EP1926807A1

EP1926807A1 - Pellets made of diacyl peroxide in a polysaccharide matrix

Info

Publication number: EP1926807A1
Application number: EP06778292A
Authority: EP
Inventors: Jens Hildebrand; Stefan Leininger; Georg Schick; Harald Jakob
Original assignee: Evonik Degussa GmbH
Current assignee: Evonik Operations GmbH
Priority date: 2005-09-15
Filing date: 2006-08-21
Publication date: 2008-06-04
Also published as: WO2007031387A1; MX2008001655A; KR20080041257A; RU2008114049A; RU2398011C2; CA2621471A1; UA88111C2; KR100956220B1; JP2009507974A; DE102005044189A1; US20090149368A1; CN101243168A

Abstract

By introducing drops of an aqueous suspension, in which particles of a diacyl peroxide are suspended and in which at least one metal ion-crosslinkable polysaccharide is dissolved, into a solution which contains the polysaccharide-crosslinking metal ions, pellets may be produced which contain particles of a diacyl peroxide embedded into a matrix. The pellets are suitable as a bleaching component in cleaning agents.

Description

Pellets of diacyl peroxide in a polysaccharide matrix

The present invention is directed to pellets containing particles of a diacyl peroxide embedded in a matrix, a process for producing such pellets, and the use of the pellets as a bleaching ingredient in cleaning compositions.

In detergents, especially in laundry detergents, persalts, such as sodium perborate or sodium percarbonate, in combination with activators, such as tetraacetylethylenediamine, are usually used as bleaching components in order to achieve an improved cleaning action in the case of bleachable soiling. In lipophilic soiling, however, the bleaching action of these combinations leaves something to be desired. A better bleaching effect can be achieved in such soiling with diacyl peroxides, in particular aliphatic diacyl peroxides.

US 4,154,695 discloses bleaches and detergents containing a diacyl peroxide and granulation of diacyl peroxides with a phlegmatizer to reduce impact sensitivity.

WO 93/07086 discloses the use of clathrates from urea and a diacyl peroxide such as dinonanoyl peroxide as a bleaching component in detergents. WO 97/18289 discloses dishwashing detergents in powder or granular form, the preparation of which comprises mixing particles containing a diacyl peroxide first with a dispersant in liquid form and then with the other ingredients of the formulation. Carboxylated polysaccharides, in particular starches, celluloses and alginates, are also mentioned as dispersants.

WO 98/11189 and WO 00/27990 disclose liquid acid textile bleaches containing an aliphatic diacyl peroxide, for example dilauroyl peroxide, in the form of an emulsion or microemulsion.

US Pat. No. 4,515,928 discloses liquid, aqueous dispersions of diacyl peroxides which contain a surfactant as dispersant and a polyhydric alcohol, a monosaccharide or an alkaline earth metal salt as freezing point depressant. Optional additives for emulsifying the diacyl peroxide include vegetable thickeners (vegetable gums) such as starch, gelatin, pectin and sodium alginate.

US 6,602,837 discloses liquid alkaline detergent formulations containing particles of a diacyl peroxide and a chelating agent. The formulations may additionally contain a dispersant, among which numerous dispersants also include carboxylated polysaccharides, in particular alginates. GB 1 390 503 discloses liquid or gel detergents containing gel capsules in which a core material is coated with a polymer gel. The gel capsules are prepared by coextrusion with a capillary for the core material and a ring nozzle for a polymer solution, as alternatives are called gleichwirkende methods. Suitable materials for the polymer gel include polysaccharides, especially carrageenan, guar gum, alginic acid and amylopectin, and pectins such as low methoxylated amidopectins and low methoxylated ones

Called citrus pectins. As a possible core material, bleaching agent is mentioned inter alia, but without specifying its structure. GB 1 390 503 also teaches on page 3, lines 76 to 79, that in the presence of calcium ions, no alginate should be used.

The formulations for detergents which comprise a diacyl peroxide, which are known from the prior art, have a storage stability which is not yet sufficient in practice if they contain alkaline reacting and / or oxidation-sensitive components which are able to react with the diacyl peroxide. Therefore, there is a need to formulate diacyl peroxides in a form that can be safely prepared and stored and that can be used in detergent formulations without such undesirable reactions with ingredients of the detergent formulation.

The invention relates to pellets comprising a matrix of at least one crosslinked by metal ions polysaccharide and embedded in this matrix particles of a diacyl peroxide. The invention also provides a process for producing such pellets comprising the steps

a) preparing an aqueous suspension in which particles of a diacyl peroxide are suspended and in which at least one metal ion crosslinkable polysaccharide is dissolved, and

b) introducing drops of the suspension a) into a solution containing the polysaccharide crosslinking metal ions.

The invention furthermore relates to cleaning compositions which comprise pellets according to the invention and at least one anionic and / or nonionic surfactant.

The pellets according to the invention comprise a matrix of at least one metal ion crosslinked

Polysaccharide. The term matrix designates a solid phase which encloses the particles of a diacyl peroxide embedded therein and which dissolves in an aqueous medium in the case of partial or complete replacement of the crosslinking metal ions with non-crosslinking metal ions until the particles of the diacyl peroxide embedded in the matrix are released become.

Suitable polysaccharides for the matrix are all water-soluble polysaccharides, which can be crosslinked by metal ions to form a water-insoluble gel. Preferred are polysaccharides containing carboxylic acid groups, with pectins, alginates and carrageenans being preferred. Pectins, alginates and carrageenans crosslinkable by metal ions are known to those skilled in the art from Ullmann ^'s Encyclopedia of Industrial Chemistry Vol. A25, pages 24-45. In a particularly preferred embodiment, the polysaccharide is a pectin having a degree of methoxylation of less than 50 mol% or an alginate, and the crosslinking metal ions are calcium ions.

In another particularly preferred embodiment, the polysaccharide is a carrageenan and the crosslinking metal ions are potassium ions.

The matrix of the pellets according to the invention preferably comprises more than 50% by weight of metal ion crosslinked polysaccharide, and more preferably more than 80% by weight. In addition to the polysaccharide crosslinked by metal ions, the matrix of the pellets according to the invention may also comprise further constituents, such as, for example, disintegrants.

Suitable disintegrants are all substances known to those skilled in the art which, upon contact of the pellets according to the invention with an aqueous medium, assist the release of the particles of diacyl peroxide embedded in the matrix. A suitable disintegrating agent is, for example, a mixture of sodium bicarbonate and citric acid.

The pellets of the invention also comprise particles of a diacyl peroxide embedded in the matrix. Diacyl peroxides are compounds of the general formula F ^ -C (O) OOC (O) -R ² , in which R ¹ and R ^{2 are} an organic radical. Preferably, the pellets according to the invention contain particles of an aliphatic diacyl peroxide, for R ¹ and R ^{2 are} independently alkyl groups of 8 to 20 carbon atoms. Preferably, the particles of diacyl peroxide have a melting point greater than 40 ° C. The pellets according to the invention particularly preferably contain embedded particles of di-n-decanoyl peroxide (R = n-nonyl), di-n-undecanoyl peroxide (R = n-decyl) or dilauroyl peroxide (R = n-undecyl).

The embedded in the matrix particles of diacyl peroxide preferably have a mass-based average

Particle size dso in the range of 5 to 100 microns and more preferably in the range of 10 to 50 microns. By choosing the particle size in this range, on the one hand, a good storage stability of the pellets according to the invention is achieved and, on the other hand, in the release of the diacyl peroxide from the matrix of the pellets, a large surface of the released particles is ensured, whereby a rapid bleaching effect is achieved.

The proportion of particles of diacyl peroxide embedded in the matrix in the pellets according to the invention is preferably in the range from 30 to 97% by weight, in particular from 60 to 90% by weight. In this area, on the one hand, a complete covering of the particles of the diacyl peroxide by the matrix and thus good storage stability is ensured and, on the other hand, a high proportion of bleach-active components in the pellets is achieved.

The pellets according to the invention preferably have a spherical shape. The size of the invention

Pellets can be chosen in a wide range. For use in solid granular detergents, the pellets of the invention Preferably, a mass-based average particle size 0I50 in the range of 0.4 to 2 mm, wherein more preferably the proportion of pellets with a diameter of less than 0.2 mm is less than 10 wt .-%. For use in liquid or gel-like detergents, the pellets according to the invention preferably have an average particle size d 50 in the range from 0.1 to 1.2 mm, particularly preferably 0.3 to 0.8 mm.

The pellets according to the invention have the advantage that they are stable on storage and only slowly lose in storage on active oxygen and a low

Have tendency to caking. The pellets of the invention also show a high storage stability in detergent formulations, in particular in

Formulations containing alkaline component.

The process according to the invention for the preparation of the pellets according to the invention comprises at least two steps, wherein in the first step an aqueous suspension is prepared in which particles of a diacyl peroxide are suspended and in which at least one polysaccharide crosslinkable by metal ions is dissolved, and in a second step drops of the first suspension prepared in a solution containing the polysaccharide crosslinking metal ions.

For the preparation of the aqueous suspension in the first step, the polysaccharides and the

Particles of diacyl peroxide used, which were previously mentioned as preferred for the pellets according to the invention. The proportion of the polysaccharide to the aqueous suspension is preferably in the range of 0.5 to 5 wt .-%, particularly preferably from 1 to 2 wt .-%. The proportion of the particles of diacyl peroxide in the aqueous suspension is preferably in the range of 1 to 15 wt .-%, particularly preferably 6 to 12 wt .-%.

Preferably, the aqueous suspension prepared in the first step additionally contains a dispersant that slows or prevents the sedimentation of the particles of the diacyl peroxide. The share of

Dispersant to the aqueous suspension is preferably in the range of 0.1 to 5 wt .-%. Suitable dispersants for diacyl peroxides are known to those skilled in the art, for example from US 3,988,261 column 10, line

8 to column 12, line 53.

In the first step, the preparation of the aqueous suspension is preferably carried out by mixing an aqueous

Suspension of the diacyl peroxide with an aqueous solution of the metal ion crosslinkable polysaccharide. Aqueous suspensions of diacyl peroxides are commercially available, for example dilauroyl peroxide as a 40% by weight suspension under the trade name LP-40-SAQ from Degussa.

In the second step of the process according to the invention, drops of the suspension prepared in the first step are introduced into a solution which contains the polysaccharide-crosslinking metal ions. The concentration of the metal ions in this solution is chosen so that the polysaccharide in the suspension from the first step is dissolved, is crosslinked by the metal ions to a water-insoluble gel. Preferably, the concentration of the metal ions in the solution used in the second step is in the range of 0.01 to 1 mol per liter, more preferably 0.05 to 0.5 mol per liter.

When introducing the drops of the suspension from the first step into the solution containing crosslinking metal ions, a skin of crosslinked polysaccharide gel first forms around each of the introduced drops. The droplets thus enveloped then cure by diffusion of metal ions into the interior of the droplets to form the pellets according to the invention.

The solution used in the second step of the process preferably contains the crosslinking metal ions in the form of the chloride salts, in particular calcium ions in the form of calcium chloride or potassium ions in the form of potassium chloride.

The introduction of drops of the suspension prepared in the first process step into the solution containing the polysaccharide-crosslinking metal ions can be carried out by any method known to those skilled in the art for introducing drops. In a preferred embodiment of the method, the drops of the

Suspension introduced via one or more vibrating nozzles in the metal ion-containing solution, wherein the amplitude and frequency of the vibration is selected so that form drops of uniform size. With this embodiment of the method pellets according to the invention can be produced with a narrow particle size distribution. Preferably, the pellets obtained in the second step of the process according to the invention are separated from the liquid phase in a subsequent step and then dried. For the separation of the pellets from the liquid phase and the subsequent drying, all solid / liquid separation processes and drying processes known to those skilled in the art can be used. The separation of the pellets from the liquid phase can be carried out, for example, by filtering, decanting or centrifuging. The drying of the pellets can be carried out by preferably vacuum drying, fluidized-bed drying in a stream of air or by suspending the pellets in a dehydrating solvent, preferably methanol, ethanol or isopropanol. The drying is preferably carried out to a water content of less than 50 wt .-%, more preferably less than 20 wt .-%. Preferably, the drying takes place at a temperature of the pellets in the range of 0 to 50 ° C. For drying the pellets, temperatures above the melting point of the in the

Matrix embedded diacyl peroxide can be applied without it comes to a caking of the pellets.

The process of the invention can be carried out particularly safely, since the diacyl peroxide is not pure

Shape must be handled, especially at elevated temperature, as is the case in processes in which a melt of the diacyl peroxide is processed.

In addition, pellets having a narrow particle size distribution which are not prone to segregation in granular detergent formulations can be produced by the process according to the invention. The pellets according to the invention can be used advantageously as bleach-active constituents in cleaning agents. Detergents for the purposes of the invention are all preparations which contain at least one anionic and / or nonionic surfactant and are suitable in conjunction with water for cleaning surfaces. A preferred form of cleaning agents for the purposes of the invention are detergents which are suitable for cleaning textiles in an aqueous wash liquor. Another preferred in the context of the invention, the form of detergents are machine dishwashing detergents, which are suitable for machine cleaning of dishes and cutlery.

Another object of the invention are detergents containing pellets according to the invention. The cleaning agents according to the invention preferably contain the pellets according to the invention in an amount of from 1 to 40% by weight, based on the total amount of the cleaning agent.

The cleaning agents according to the invention may have a solid form and may then contain, in addition to the pellets according to the invention, further components in the form of powder or in the form of granules. In addition, they may also comprise compressed molded bodies, it being possible for the pellets according to the invention to form part of the pressed molded bodies. Such compressed molded articles in the form of extrudates, pellets, briquettes or tablets can be produced by press agglomeration processes, in particular by extrusion, extrusion, hole pressing,

Roll compacting or tableting. For carrying out the pressing agglomeration, the cleaning agents according to the invention may additionally contain a binder which the moldings in the Press agglomeration gives a higher strength. Preferably, in cleaning compositions according to the invention, which comprise pressed molded bodies, but no additional binder is used, and one of the detergent-active constituents, for example a nonionic surfactant, fulfills the function of the binder.

The cleaning agents according to the invention may moreover also have a liquid form or gel form and contain the pellets according to the invention dispersed in a liquid phase or a gel phase. In addition to the pellets according to the invention, further particles can be dispersed in the liquid phase or the gel phase. The rheological properties of the liquid phase, or the gel phase are preferably adjusted so that the particles dispersed therein remain suspended and not settle during storage. The composition of a liquid phase is therefore preferably selected to have thixotropic or pseudoplastic flow properties. To adjust such flow properties, suspension aids, such as swelling clays, in particular montmorillonites, precipitated and fumed silicas, vegetable gums, in particular xanthans and polymeric gelling agents, such as carboxyl-containing vinyl polymers may be added.

Detergents according to the invention in liquid form or gel form which contain more than 5% by weight of water preferably additionally contain, in dissolved form, metal ions in a concentration which leads to crosslinking of the polysaccharide contained in the pellets according to the invention. The concentration of the metal ions in the liquid or gel detergent is preferably so it has been chosen that the intended use of the cleaning agent by dilution with water achieves a concentration of the metal ions which is so low that the polysaccharide dissolves due to the lower crosslinking and releases the embedded particles of the diacyl peroxide.

In addition to the pellets according to the invention and at least one anionic and / or nonionic surfactant, the cleaning agents according to the invention may contain, for example, cationic surfactants, builders, alkaline components, persalts, bleach activators, enzymes, chelating complexing agents, grayness inhibitors, foam inhibitors, optical brighteners, fragrances and dyes ,

Suitable anionic surfactants are, for example, surfactants with sulfonate groups, preferably alkylbenzenesulfonates, alkanesulfonates, alpha-olefinsulfonates, alpha-sulfofatty acid esters or sulfosuccinates. at

Alkylbenzenesulfonates are those having a straight-chain or branched alkyl group of 8 to 20

Carbon atoms, in particular with 10 to 16

Carbon atoms are preferred. Preferred alkanesulfonates are those having straight-chain alkyl chains with 12 to 18

Carbon atoms. In the case of alpha-olefin sulfonates, the reaction products of the sulfonation of alpha-olefins having 12 to 18 carbon atoms are preferably used. In the case of the alpha-sulfofatty acid esters, imitation products of fatty acid esters of fatty acids having 12 to 18 carbon atoms and short-chain alcohols having 1 to 3 carbon atoms are preferred. Also suitable as anionic surfactants are surfactants having a sulfate group in the molecule, preferably alkyl sulfates and ether sulfates. Preferred alkyl sulfates are those having straight chain alkyl radicals of 12 to 18 carbon atoms. Also suitable are beta-branched alkyl sulfates and in the middle of the longest alkyl chain mono- or polysubstituted alkyl-substituted alkyl sulfates. Preferred ether sulfates are

Alkyl ether sulfates obtained by ethoxylation of linear alcohols having 12 to 18 carbon atoms with 2 to 6 ethylene oxide units and subsequent sulfation. Finally, soaps may also be used as anionic surfactants, for example

Alkali metal salts of lauric acid, myristic acid, palmitic acid, stearic acid and / or natural fatty acid mixtures, such as coconut, palm kernel or tallow fatty acids.

Suitable nonionic surfactants are, for example, alkoxylated compounds, in particular ethoxylated and propoxylated compounds. Particularly suitable are condensation products of alkylphenols or fatty alcohols with 1 to 50 mol, preferably 1 to 10 mol of ethylene oxide and / or propylene oxide. Also suitable are polyhydroxy fatty acid amides in which the amide nitrogen is bonded to an organic radical having one or more hydroxyl groups, which may also be alkoxylated. Also suitable as nonionic surfactants

Alkyl glycosides having a straight-chain or branched alkyl group having 8 to 22 carbon atoms, in particular having 12 to 18 carbon atoms and a mono- or diglycoside radical, which is preferably derived from glucose.

Suitable cationic surfactants are, for example, mono- and dialkoxylated quaternary amines with one on nitrogen bonded Cβ ~ to Cis-alkyl radical and one or two hydroxyalkyl groups.

The detergents of the invention may further contain builders capable of binding calcium and magnesium ions dissolved in the water when used.

Suitable builders are alkali metal phosphates and

Alkali metal polyphosphates, in particular

Pentasodium triphosphate; water-soluble and water-insoluble sodium silicates, in particular

Phyllosilicates of the formula NasSi2θs; Zeolites of structures

A, X and / or P; and trisodium citrate. In addition to the

Builders can also use organic cobuilders, such as

Example polyacrylic acid, polyaspartic acid and / or acrylic acid copolymers with methacrylic acid, acrolein or sulfonic acid-containing vinyl monomers, and their

Alkali metal salts are used.

The cleaning agents according to the invention may additionally contain alkaline components which, when used as intended in the aqueous cleaning agent solution, have a pH in the range from 8 to 12. As alkaline components, especially sodium carbonate, sodium sesquicarbonate, sodium metasilicate and other soluble alkali metal silicates are suitable.

The detergents according to the invention may contain, in addition to the pellets according to the invention, persalts, for example alkali metal perborates, alkali metal carbonate perhydrates, alkali metal persilicates, alkali metal persulphates, alkali metal peroxophosphates and alkali metal peroxopyrophosphates, from which hydrogen peroxide is liberated in an aqueous medium. preferred Persalts are sodium perborate tetrahydrate, sodium perborate monohydrate and sodium carbonate perhydrate. Particularly preferred is sodium carbonate perhydrate. Suitable sodium carbonate perhydrate for use in liquid detergents is known from WO 2004/056955. The combination of the diacyl peroxide-containing pellets of this invention with a peroxide releasing hydrogen peroxide achieves a synergistic bleaching effect beyond the action of the individual components, especially when the detergent contains alkaline components. The synergistic effect is presumably based on a reaction between the diacyl peroxide of the structure RC (O) OOC (O) -R with hydrogen peroxide to form two molecules of percarboxylic acid of the structure RC (O) OOH, presumably by attack of the hydroperoxide anion H00 ^~ on the diacyl peroxide ,

Suitable bleach activators for the detergents according to the invention are, in particular, compounds with one or more perhydrolysis-capable of nitrogen or on

Oxygen-bonded acyl groups with the released from the sodium percarbonate particles

React hydrogen peroxide in the aqueous detergent solution to peroxycarboxylic acids. Examples of such compounds are polyacylated alkylenediamines, in particular tetraacetylethylenediamine (TAED); acylated triazine derivatives, in particular 1, 5-diacetyl-2, 4-dioxohexahydro-l, 3, 5-triazine (DADHT); acylated glycolurils, especially tetraacetylglycoluril (TAGU); N-acylimides, especially N-nonanoylsuccinimide (NOSI); acylated phenolsulfonates, especially n-nonanoyl or iso-nonanoyloxybenzenesulfonate (n- or iso-NOBS); Carboxylic acid anhydrides, such as phthalic anhydride; acylated polyhydric alcohols, such as ethylene glycol diacetate, 2, 5-diacetoxy-2,5-dihydrofuran, acetylated sorbitol and Mannitol and acylated sugars, such as pentaacetylglucose; enol; and N-acylated lactams, especially N-acyl caprolactams and N-acyl valerolactams. Likewise suitable as bleach activators are amino-functionalized nitriles and their salts (nitrile quats), which are described, for example, in the journal Surfactants Surf. Det. 1997, 34 (6), pages 404-409. As bleach activators it is also possible to use transition metal complexes which can activate hydrogen peroxide for bleaching stain removal. Suitable transition metal complexes are known, for example, from EP-A 0 544 490 page 2, line 4 to page 3, line 57; WO 00/52124 page 5, line 9 to page 8, line 7 and page 8, line 19 to page 11, line 14; WO 04/039932, page 2, line 25 to page 10, line 21; WO 00/12808 page 6, line 29 to page 33, line 29; WO 00/60043 page 6, line 9 to page 17, line 22; WO 00/27975, page 2, lines 1 to 18 and page 3, line 7 to page 4, line 6; WO 01/05925, page 1, line 28 to page 3, line 14; WO 99/64156, page 2, line 25 to page 9, line 18; such as

GB-A 2 309 976, page 3, line 1 to page 8, line 32.

The detergents according to the invention may furthermore contain enzymes which enhance the cleaning action, in particular lipases, cutinases, amylases, neutral and alkaline proteases, esterases, cellulases, pectinases, lactases and / or peroxidases. The enzymes may be adsorbed on carriers or embedded in Hullsubstanzen to protect them against decomposition.

The cleaning agents according to the invention may additionally contain chelating transition-metal complexing agents with which a catalytic decomposition of active oxygen compounds in the wash liquor, or avoid the aqueous detergent solution and can accelerate the dissolution of the polysaccharide matrix of the pellets according to the invention by complexing the crosslinking metal ions. Suitable examples are phosphonates, such as hydroxyethane-1, 1-disphosphonate, nitrilotrimethylene phosphonate, diethylene triamine penta (methylene phosphonate), ethylene diamine tetra (methylene phosphonate), hexamethylene diamine tetra (methylene phosphonate) and their alkali metal salts. Also suitable are nitrilotriacetic acid and polyaminocarboxylic acids, in particular ethylenediaminetetraacetic acid,

Diethylenetriaminepentaacetic acid, ethylenediamine-N, N'-disuccinic acid, methylglycinediacetic acid and polyaspartates, and their alkali metal and ammonium salts Finally, polybasic carboxylic acids and in particular hydroxycarboxylic acids, in particular tartaric acid and citric acid, are also suitable as chelating complexing agents.

Detergents according to the invention may additionally contain redeposition inhibitors, which keep suspended dirt suspended and prevent the dirt from being re-applied to the cleaned surface. Suitable redeposition inhibitors are, for example, cellulose ethers such as carboxymethylcellulose and their alkali metal salts, methylcellulose, hydroxyethylcellulose and hydroxypropylcellulose. Also suitable is polyvinylpyrrolidone.

The cleaning agents according to the invention can furthermore also contain foam inhibitors which reduce the foaming in the aqueous cleaning solution. Suitable foam inhibitors are, for example, organopolysiloxanes such as Polydimethylsiloxane, paraffins and / or waxes, and mixtures thereof with finely divided silicas.

Detergents according to the invention may optionally contain optical brighteners which are applied to the fiber in the

UV absorb light and fluoresce blue to compensate for yellowing of the fiber. Suitable optical brighteners are, for example derivatives of diaminostilbenedisulfonic acid, such as alkali metal salts of 4,4 ^Λ -bis- (2-anilino-4-morpholino-l, 3, 5-triazinyl-6-amino) - stilbene-2, 2 ^Λ disulfonic acid or substituted diphenyl, such as alkali metal salts of 4,4 ^Λ bis- (2-sulfostyrlyl) -diphenyl.

Finally, the cleaning agents according to the invention may also contain fragrances and dyes.

Detergents according to the invention in liquid or gel form may additionally contain up to 30% by weight of organic solvents, for example methanol, ethanol, n-propanol, isopropanol, n-butanol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol , 1, 4-Butylene glycol, glycerol, diethylene glycol, ethylene glycol methyl ether, ethanolamine, diethanolamine and / or triethanolamine.

The detergents according to the invention show a better storage stability with lower losses of active oxygen content during storage, in particular for detergents, the alkaline compared to detergents containing non-inventive particles of diacyl peroxides Components included. At the same time there is a reduced oxidative attack on oxidation-sensitive components of the cleaning agent, such as enzymes, optical brighteners, fragrances and dyes

A preferred embodiment of the detergents according to the invention are machine dishwashing detergents in the form of tablets, the tablets also containing, in addition to the pellets according to the invention, a silver corrosion inhibitor. Silver corrosion inhibitors in the context of the invention are agents that prevent or reduce the tarnishing of non-ferrous metals, in particular silver, during machine cleaning with the machine dishwashing detergent. The silver corrosion inhibitors used are preferably one or more compounds from the series of triazoles, benzotriazoles, bisbenzotriazoles, aminotriazoles and alkylaminotriazoles. The compounds of the substance classes mentioned may also have substituents, such as linear or branched alkyl groups having 1 to 20 carbon atoms, as well as vinyl, hydroxy, thiol or halogen radicals. In the case of bisbenzotriazoles, preference is given to compounds in which the two benzotriazole groups are each connected in the 6-position via a group X in which X is a bond, a straight-chain, optionally containing one or more C 1 to C _{4 radicals} .

Alkyl group substituted alkylene group having preferably 1 to 6 carbon atoms, a cycloalkyl group having at least 5 carbon atoms, a carbonyl group, a sulfonyl group, an oxygen or a sulfur atom. A particularly preferred

Silver corrosion inhibitor is tolyltriazole.

Inventive, a silver corrosion inhibitor containing machine dishwashing detergent in the form of tablets show significantly lower yellowing of the tablets during storage of the machine dishwashing detergent compared to machine dishwashing detergents in which the diacyl peroxide is not embedded in a matrix of a polysaccharide.

Examples

example 1

25 parts by weight of a 40 wt .-% aqueous suspension of

Dilauroyl peroxide was mixed with 75 parts by weight of

2.5 wt .-% aqueous solution of sodium alginate mixed. The resulting suspension was dropped through a 0.5 mm diameter oscillating nozzle at a flow rate of 0.21 g / sec at a vibration frequency of 410 Hz into a stirred 0.1 M aqueous solution of calcium chloride. Thereafter, the obtained spherical pellets were filtered off and dried at 30 ⁰ C in vacuo for 48 h.

The pellets obtained were practically insoluble in deionized water at 20 ⁰ C and exhibited within 4 h no discernible change. In contrast, in a 0.1 M solution of EDTA, the pellets dissolved within 5 min to release the Dilauroylperoxidpartikel in the form of a suspension.

The storage stability of the pellets was determined by microcalorimetric determination of the energy release during storage at 40 ^° C. using a ^TAM® Thermal Activity Monitor from Thermometric AB, Järfälla (SE) and the TAM value was determined as the measured value after 48 h. The obtained pellets showed a TAM value of 2.3 μW / g. A peroxygen compound is sufficiently storage stable if the TAM value for energy release after 48 h is not more than 10 μW / g.

Claims

claims

Claims 1. A pellet comprising a matrix of at least one metal ion crosslinked polysaccharide and particles of a diacyl peroxide embedded in the matrix.

2. Pellets according to claim 1, characterized in that the polysaccharide is selected from the series of pectins, alginates and carrageenans and mixtures thereof.

3. Pellets according to claim 2, characterized in that the metal ions are calcium ions and the polysaccharide is selected from the series of pectins having a degree of methoxylation of less than 50 mol% and the alginates.

4. Pellets according to claim 2, characterized in that the metal ions are potassium ions and the polysaccharide is a carrageenan.

5. Pellets according to claim 1, characterized in that the diacyl peroxide acyl radicals R-C (O) contains, in which R is an alkyl group having 8 to 20 carbon atoms, preferably n-nonyl, n-decyl or n-undecyl.

6. A process for producing pellets according to claim 1, comprising the steps of a) preparing an aqueous suspension in which particles of a diacyl peroxide are suspended and in the at least one crosslinkable by metal ions

Polysaccharide is dissolved and b) introducing drops of the suspension a) into a

Solution containing the polysaccharide cross-linking metal ions.

7. The method according to claim 6, characterized in that the suspension additionally contains a dispersant.

8. The method according to claim 6 or 7, characterized in that in step a) an aqueous suspension of a diacyl peroxide with an aqueous solution of

Metal ion crosslinkable polysaccharide is mixed.

9. The method according to any one of claims 6 to 8, characterized in that the pellets obtained in step b) are separated from the liquid phase and then dried.

10. A cleaning composition comprising pellets according to any one of claims 1 to 5 and at least one anionic and / or nonionic surfactant.

11. Cleaning agent according to claim 10, characterized in that it additionally contains a persalt selected from the series sodium perborate tetrahydrate, sodium perborate monohydrate and sodium carbonate perhydrate, preferably sodium carbonate perhydrate.