EP1275709B1 - Process for the production of bleach activator granules - Google Patents

Description

The present invention relates to a process for the production of cylindrical to spherical extrudates containing bleach activators, with defined particle sizes and narrow particle size distribution, which exhibit a low abrasion behavior and a good flow behavior.

Numerous patents disclose processes for producing extruded detergents and cleaners. EP 486 592 describes the production of extruded moldings in which a solid and free-flowing premix is extruded using a plasticizer and / or lubricant at relatively high pressures of between about 25 and 200 bar. The strand has such a consistency that it can be cut directly onto a predetermined granule dimension after leaving the hole shape by means of a cutting device. The plasticizers and / or lubricants mentioned are in particular aqueous anionic surfactant pastes, aqueous polymer solutions and / or nonionic surfactants which are liquid at room temperature. The extruded shaped articles which can be produced in this way generally have a size of up to 2 cm, preferably up to 0.8 cm, the length-diameter ratio advantageously being between 1: 1 and 3: 1.

As described in WO 99/27061, bleach activators are advantageously formulated in the form of cylindrical extrudates in order to ensure compatibility with other detergent constituents and a sufficient storage stability. It is assumed that the highly reactive bleach activator is predominantly embedded in the interior of the cylindrical granules and the surface predominantly consists of binding materials and plasticizer.
To avoid segregation of the different particles in the detergent formulation during transport and storage, the particle diameter should be between 0.2 mm and 2 mm, preferably between 0.5 mm and 0.8 mm, the particle length is in the range of 0.5 mm to 3.5 mm, ideally between 0.9 mm and 2.5 mm.
All previously described processes for the production of extrudates either provide moldings having a relatively broad particle size distribution and / or a comparatively high dust content. The particles have sharp corners and edges at the interfaces which cause high abrasion with dust formation and unfavorable flow behavior. If the preparation of the extrudates under high compression forces, the dissolving behavior of the particles is significantly impaired.

The object of the invention was to produce cylindrical to spherical extrudates containing bleach activators for use in detergents or cleaners, which have a very narrow particle size distribution and at the same time a low Abriebtendenz, low dust formation, a favorable flow behavior, and a good dissolving behavior show during the washing and cleaning process.

The invention relates to a process for the preparation of bleach activator granules, characterized in that a mixture of bleach activator, anionic or nonionic surfactant and polyalkylene glycol at temperatures of 40 to 90 ° C, preferably 60 to 80 ° C and a pressure of 10 to Extruded at 30 bar and granulated the extrudates obtained at a temperature of 60 to 90 ° C, preferably 60 to 80 ° C on a Rondier.

Suitable bleach activators are, for example, N, N, N ', N'-tetraacetylethylenediamine (TAED), glucose pentaacetate (GPA), xylose tetraacetate (TAX), sodium 4-benzoyloxybenzenesulphonate (SBOBS), sodium trimethylhexanoyloxybenzenesulphonate (STHOBS), tetraacetylglycoluril (TAGU), Tetraacetylcyanoic acid (TACA), di-N-acetyldimethylglyoxime (ADMG), 1-phenyl-3-acetylhydantoin (PAH), nonanoylcaprolactam phenylsulfonate ester (APES), nitrilotriacetate (NTA), preferably the sodium salt of nonanoyloxybenzenesulphonate (NOBS), the sodium salt of 3,5,5-trimethylhexanoyloxyphenylsulfonate (iso-NOBS) or the sodium salt of acetoxyphenylsulfonate (ABS).

Preferred anionic surfactants are alkali salts, ammonium salts, amine salts and salts of amino alcohols of the following compounds: alkyl sulfates, alkyl ether sulfates, alkyl amide sulfates and ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, alkyl sulfonates, alkyl amide sulfonates, alkylaryl sulfonates, alpha-olefin sulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkyl amide sulfosuccinates, alkyl sulfoacetates, Alkyl polyglycerol carboxylates, alkyl phosphates, alkyl ether phosphates, alkyl sarcosinates, alkyl polypeptides, alkyl amido coppeptides, alkyl isethionates, alkyl taurates, alkyl polyglycol ether carboxylic acids or fatty acids such as oleic acid, ricinoleic acid, palmitic acid; Stearic acid, coconut oil acid salt or hydrogenated coconut oil acid salts. The alkyl radical of all these compounds normally contains 8-32, preferably 8-22 C atoms. Particularly preferred are linear straight-chain alkylbenzenesulfonates, in particular having a C ₈ -C ₂₀ -, more preferably having a C _11-13 -alkyl group.

Preferred nonionic surfactants are polyethoxylated, polypropoxylated or polyglycerolated ethers of fatty alcohols, polyethoxylated, polypropoxylated and polyglycerinated fatty acid esters, polyethoxylated esters of fatty acids and of sorbitol, polyethoxylated or polyglycerolated fatty amides.

Suitable polyalkylene glycols are polyethylene glycols, 1,2-polypropylene glycols and also modified polyethylene glycols and polypropylene glycols. The modified polyalkylene glycols include in particular sulfates and / or disulfates of polyethylene glycols or polypropylene glycols having a molecular weight between 600 and 12000 and in particular between 1000 and 4000. Another group consists of mono- and / or disuccinates of polyalkylene glycols, which in turn have molecular weights between 600 and 6000, preferably between 1000 and 4000. Also included are ethoxylated derivatives such as trimethylolpropane having 5 to 30 EO.
The polyethylene glycols preferably used may be a linear or have branched structure, in particular linear polyethylene glycols are preferred. Particularly preferred polyethylene glycols include those having molecular weights between 2,000 and 12,000, advantageously about 4,000, wherein polyethylene glycols having molecular weights below 3500 and above 5000, especially in combination with polyethylene glycols having a molecular weight of 4000, can be used and advantageously such combinations are more than 50 wt .-%, based on the total amount of polyethylene glycols, polyethylene glycols having a molecular weight between 3500 and 5000 have.
The modified polyethylene glycols also include one or more end-capped polyethylene glycols, the end groups preferably being C ₁ -C ₁₂ -alkyl chains, preferably C ₁ -C ₆ , which may be linear or branched. Unilaterally end-capped polyethylene glycol derivatives may also correspond to the formula Cx (EO) y (PO) z, where Cx may be an alkyl chain having a C chain length of 1 to 20, y 50 to 500 and z 0 to 20. Likewise suitable are low molecular weight polyvinylpyrrolidones and derivatives of these having molecular weights of up to a maximum of 30,000. Preferred here are molecular weight ranges between 3,000 and 30,000. Polyvinyl alcohols are preferably used in combination with polyethylene glycols.

To improve the plasticizing and sliding properties, but also the abrasion resistance of the bleach activator granules may additionally one or more components added, which are liquid at room temperature or present under the processing conditions as a melt, for example linear or branched fatty acids, especially nonanoic acid or ethoxylated fatty acids 2 to 100 EO.

The mixture of all components described above may additionally contain small amounts of a solvent, preferably less than 15 wt .-%, preferably less than 10 wt .-%, more preferably less than 7 wt .-%. Preferred solvent is water.

Other suitable additives are substances that increase the pH during storage and Affect application. These include organic carboxylic acids or their salts, such as citric acid in anhydrous or hydrated form, glycolic acid, succinic acid, maleic acid or lactic acid. In addition, additives are possible which influence the bleaching ability, such as complexing agents and transition metal complexes, for example iron, cobalt or manganese-containing metal complexes as described in EP-A-0 458 397 and EP-A-0 458 398.

Particularly advantageous embodiments of the invention contain as bleach activator the sodium salt of nonanoyloxyphenylsulphonate (NOBS), as solubilizer linear straight-chain alkylbenzenesulphonates, in particular with a C ₈ -C ₂₀ -, more preferably with a C 11-13 -alkyl group (LAS), as well as nonanoic acid and polyethylene glycol ( PEG) 4000 as consistency regulator and plasticizer, wherein the proportion of NOBS 70 wt .-% to 90 wt .-%, preferably 80 wt .-% to 87 wt .-%, particularly preferably 81 wt .-% to 85 wt. %, to LAS 2 wt .-% to 10 wt .-%, preferably 3 wt .-% to 5 wt .-%, particularly preferably 3.7 wt .-% to 4.5 wt .-%, of nonanoic acid 0 , 1 wt .-% to 6 wt .-%, preferably 1 wt .-% to 4 wt .-%, particularly preferably 2.5 wt .-% to 3.5 wt .-%, of PEG 4000 1 wt. -% to 15 wt .-%, preferably 5 wt .-% to 10 wt .-%, particularly preferably 7 wt .-% to 8 wt .-% is.

Advantageously, bleach activator, for example nonanoyloxyphenylsulphonate (NOBS) and anionic or nonionic surfactant, for example alkylbenzenesulphonate (LAS) are mixed in powder form, plasticizers, for example nonanoic acid and PEG 4000 at 50 to 70 ° C, preferably 60 to 65 ° C and registered at a temperature in the range from 60 to 70 ° C and a pressure of 14 bar to 22 bar extruded strand-shaped. In a preferred embodiment of the invention, the mixture is fed continuously to a 1-shaft extruder, 2-shaft extruder or 2-screw extruder with concurrent or counter-rotating screw guide whose housing and its extruder granulating head to be heated to the predetermined extrusion temperature can. Under the shearing action of the extruder screws, the mixture is compacted under pressure, plasticized, extruded in the form of strands through the hole die plate in the extruder head, optionally with fine-grained anti-caking agent, For example, TiO2, silica, zeolite, dusted own dust, crushed into coarse straw pieces and transferred to a to 40 to 90 ° C, preferably 60 to 80 ° C, especially 60 to 65 ° C heated Rondierer.

By the subsequent Rondierverfahren cylindrical to spherical granules are obtained with defined particle sizes and very narrow particle size distribution, wherein the particle diameter between 0.2 mm and 2 mm, preferably between 0.5 mm and 0.8 mm, the particle length in the range of 0.5 mm to 3.5 mm, ideally between 0.9 mm and 2.5 mm. The extrudates are placed directly on the Rondierer or possibly coarsely pre-crushed. In a preferred embodiment, the molding process according to the invention is carried out continuously in cascade operation, but also a batch-wise work is possible.
The size and shape of the particles can be influenced and brought about in the Rondierverfahren by several parameters. The forming process is determined by the filling quantity, the temperature of the mixture, the residence time of the mixture in the Rondier, by the rotation speed of the Rondierscheibe, as well as by the plastic deformability of the mixture.
With decreasing filling volume in the rounding device, shorter cylindrical granules and a narrower distribution of the particle sizes are obtained. With decreasing temperature and thus decreasing plasticity longer granules are obtained, with further cooling, the dust content increases sharply.
The residence time of the mixture in the ringer depends not only on the plasticity of the filling amount and is preferably 10 sec. To 120 sec., Particularly preferably 20 sec. To 60 sec., The peripheral speed 10 m / sec. to 30 m / sec., preferably 12 m / sec. up to 20 m / sec.

In a particular embodiment, the temperature in the ringer is controlled by supplying air or gas (N2), preferably via the cleavage device. The temperature of the air or gas streams is 50 to 120 ° C, preferably 60 to 90 ° C, so that depending on the design of the Rondierers the desired working temperature can be maintained in Rondierer.
After the molding process, the cylindrically shaped and rounded Particles in a downstream apparatus, preferably cooled in a fluid bed cooler in cold air or gas stream to temperatures below 40 ° C in order to avoid sticking of the granules.

The granules thus obtained are characterized by a favorable flow behavior, low dust content, high abrasion resistance.
The bulk density is in the range 300 g / l to 2000 g / l, preferably in the range 400 g / l to 1500 g / l and particularly preferably in the range of 500-800 g / l.

The resulting granules according to the invention are suitable directly for use in detergents and cleaners. If necessary, they can be provided with a coating cover.

Further possible additives are substances which react with the peroxycarboxylic acid released from the activator in the wash liquor to form reactive intermediates, such as dioxiranes or oxaziridines, and in this way can increase the reactivity. Corresponding compounds are ketones and sulfonimines according to US-A-3 822 114 and EP-A-0 446 982.

The amount of the additive depends in particular on its nature. Thus, acidifying additives and organic catalysts to increase the performance of the peracid in amounts of 0 to 20 wt .-%, in particular in amounts of 1 to 10 wt .-%, based on the total weight, added, metal complexes in concentrations in the ppm range.
The resulting granules are characterized by a very good abrasion resistance and storage stability in powdered detergent, cleaning and disinfectant formulations. They are ideal for use in heavy-duty detergents, stain salts, machine dishwashing detergents, powdered all-purpose cleaners and denture cleaners.

In these formulations, the granules of the invention are usually used in combination with a hydrogen peroxide source. Examples include perborate monohydrate, perborate tetrahydrate, percarbonates and Hydrogen peroxide adducts on urea or amine oxides. In addition, the formulation according to the prior art may have other detergent ingredients, such as organic and inorganic builders and co-builders, surfactants, enzymes, brighteners and perfume.

The following examples are intended to illustrate the invention without limiting it thereto.

Example 1 Production of a NOBS Granule, Active Ingredient Content: 84.4% by Weight

Granule diameter d: 0.7 mm Granule length I: 1.4 mm

844 g of the sodium salt of nonanoyloxybenzenesulphonate (NOBS), 50 g of linear C _11-13 -alkylbenzenesulfonate, Na salt, 31 g of nonanoic acid and 75 g of polyethylene glycol 4000 are in the ploughshare mixer (Lödige manufacturer) at room temperature at a speed of 120 per minute and switched on Knife head homogeneously mixed in a period of 150 seconds, heated to 65 to 71 ° C, transferred to a single-screw dome extruder (manufacturer Fitzpatrick) with a bore diameter of 0.7 mm in the punch die and at an extruder screw speed of 45 per minute, a throughput of 287 g / min. extruded. Subsequently, 500 g extrudates at a temperature of 65 to 69 ° C in a batch-Rondierer (manufacturer Schlüter) with a diameter of 0.3 m at a speed of 1000 per minute, a peripheral speed of 15.71 m / sec and a residence time 40 seconds to the previously stated particle shape. After the molding process, the cylindrically shaped and rounded particles are cooled in a downstream apparatus, preferably in a fluid bed cooler in the cold air stream, in order to avoid sticking of the granules. 94.9% of the granules obtained correspond to the target size of d = 0.7 mm and an average length of I ₅₀ = 1.37 mm. The width of the length distribution is in the range of I ₁₀ = 1.03 mm to I ₉₀ = 1.66 mm. 5.05% fines and 0.05% coarse fraction are screened off, the sieved target fraction has a bulk density of 692 g / l.

Example 2 Production of a NOBS Granulate, Active Ingredient Content: 85.8% by Weight

Granule diameter d: 0.7 mm Granule length I: 1.4 mm

858 g of the sodium salt of nonanoyloxybenzenesulphonate (NOBS), 42 g of linear C _11-13 -alkylbenzenesulfonate, Na salt, 29 g of nonanoic acid and 71 g of polyethylene glycol 4000 are in the ploughshare mixer (manufacturer Lödige) at room temperature at a speed of 120 per minute and switched on Knife head homogenously mixed in a period of 150 seconds, heated to 62 to 65 ° C, transferred to a single-screw dome extruder (manufacturer Fitzpatrick) with a bore diameter of 0.7 mm in the hole die and at an extruder screw speed of 45 per minute, a throughput of 199 g / min. extruded. Subsequently, 1 kg of extrudates at a temperature of 60 to 62 ° C in a batch-Rondierer (manufacturer Schlüter) with a diameter of 0.3 m at a speed of 1000 per minute, a peripheral speed of 15.71 m / sec and a residence time 40 seconds to the previously stated particle shape. After the molding process, the cylindrically shaped and rounded particles are cooled in a downstream apparatus, preferably in a fluid bed cooler in the cold air stream, in order to avoid sticking of the granules. 97.37% of the granules obtained correspond to the target size of d = 0.7 mm and I ₅₀ = 1.45 mm. The width of the length distribution is in the range of I ₁₀ = 1.03 mm to I ₉₀ = 1.93 mm. 2.46% fines and 0.17% coarse fraction are screened, the sieved target fraction has a bulk density of 686 g / l.

Example 3 Production of an APES Granulate

Granule diameter d: 0.7 mm Granule length I: 1.4 mm

675 g Nonanoylcaprolactamphenylsulfonatester (APES), 14.3 g linear C _11-13 -alkylbenzenesulfonate, Na salt, 10.7 g of sodium citrate and 7.5 g of water are in the ploughshare mixer (manufacturer Lödige) at room temperature at room speed homogeneously blended at 120 per minute with cutter head engaged within a period of 150 seconds, transferred to a single-screw dome extruder (manufactured by Fitzpatrick) with a bore diameter of 0.7 mm in the punching die, and an extruder screw speed of 45 per minute, throughput of 199 g / min, extruded. Subsequently, the extrudates at room temperature in a batch-Rondierer (manufacturer Schlüter) with a diameter of 0.3 m at a speed of 1000 per minute, a peripheral speed of 22.3 m / sec and a residence time of 40 seconds to the previously specified particle shape brought. After the molding process, the cylindrically shaped and rounded particles are dried in a downstream apparatus, preferably in a fluid bed dryer and cooled

Claims (12)

1. A process for the preparation of bleach activator granules, which comprises extruding a mixture comprising bleach activator, anionic or nonionic surfactant and polyalkylene glycol at temperatures of from 40 to 90°C, preferably 60 to 80°C, and a pressure of from 10 to 30 bar, and granulating the resultant extrudates at a temperature of from 60 to 90°C, preferably 60 to 80°C, on a spheronizer.
2. The process as claimed in claim 1, wherein linear or branched fatty acids or ethoxylated fatty acids having 2 to 100 EO are additionally used.
3. The process as claimed in claim 1, wherein the anionic surfactant used is an alkylarylsulfonate.
4. The process as claimed in claim 1, wherein the polyalkylene glycol used is polyethylene glycol.
5. The process as claimed in claim 1, wherein the bleach activator used is Na nonanoyloxybenzenesulfonate.
6. The process as claimed in claim 1, wherein granules are prepared which consist of 70 to 90% by weight of Na nonanoyloxybenzenesulfonate, 2 to 10% by weight of alkylbenzenesulfonate, 0.1 to 6% by weight of nonanoic acid and 1 to 15% by weight of polyethylene glycol 4000.
7. The process as claimed in claim 1, wherein the extrudates are placed directly on the spheronizer or are coarsely precomminuted.
8. The process as claimed in claim 1, wherein the temperature in the spheronizer is controlled by introducing a stream of air or gas.
9. The process as claimed in claim 1, wherein the spheronizer operates at a peripheral speed of from 10 to 30 m/sec.
10. The process as claimed in claim 1, wherein the residence time in the spheronizer is from 10 to 120 sec.
11. The process as claimed in claim 1, wherein the spheronizing process is carried out batchwise or continuously in a cascade operation.
12. The process as claimed in claim 1, wherein the extrudates are powdered with an anticaking agent.