EP0564476B1 - Enzyme preparation for washing and cleansing agents - Google Patents

Abstract

In the production of enzyme granulates with grain sizes from 0.1 to 2 mm, containing 2 to 20 % wt. proteases, lipases, amylases and/or cellulases, 10 to 50 % wt. swellable starch, 5 to 50 % wt. granulating agent, 3 to 12 % wt. water and not more than 10 % wt. water-soluble salt, by extruding an enzyme pre-mixture obtained by mixing a fermentation liquor cleared of insoluble components and concentrated with additives and spheroidizing the extrudate in a rounder, the use of relatively highly concentrated fermentation liquours has previously been necessary. By removing the insoluble components from the fermentation liquor by micro-filtration and mixing with additives which, in relation to the finished granulate, contains 10 to 35 % wt. cereal flour, it is possible, by the use of low-concentration fermentation liquors, to obtain highly active enzyme granulates with a long shelf life which are suitable for inclusion in washing and cleansing agents and are distinguished by uniform solubility properties in aqueous washing and cleansing baths.

Description

The invention relates to an enzyme granulate, a process for its preparation and the use of the granulate in solid washing and cleaning agents.

Enzymes, especially proteases, are used extensively in washing, auxiliary washing and cleaning agents. The enzymes are usually not used as concentrates, but in mixtures with a dilution and carrier material. If such enzyme preparations are mixed in with conventional detergents, a considerable reduction in the enzyme activity can occur during storage, especially if bleach-active compounds are present. The application of the enzymes to carrier salts with simultaneous granulation in accordance with German Offenlegungsschrift DT 16 17 190 or by sticking with nonionic surfactants in accordance with German Offenlegungsschrift DT 16 17 118 or aqueous solutions of cellulose ethers in accordance with German Offenlegungsschrift DT 17 87 568 does not lead to any significant improvement storage stability, since the sensitive enzymes in such mixtures are usually on the surface of the carrier substance. The storage stability of the enzymes can be significantly increased if the enzymes are encased or embedded in the carrier material and then converted into the desired particle shape by extrusion, pressing and marumerization, as described, for example, in German patent DE 16 17 232, German Offenlegungsschrift DT 20 32 768, and the German interpretations DE 21 37 042 and DE 21 37 043. However, such enzyme preparations have poor solubility properties. The undissolved particles can get caught in the laundry and contaminate it, or they can be discharged unused into the wastewater. Embedding agents known from German Offenlegungsschrift DT 18 03 099, which consist of a mixture of solid acids or acid salts and carbonates or bicarbonates and which disintegrate when water is added, improve the solvency but are themselves very sensitive to moisture and therefore require additional protective measures.

Another disadvantage of the aforementioned preparation is the fact that the enzymes can only be processed in the form of dry powders. The fermentation broths usually produced during enzyme production cannot be used in this form, but must be dewatered beforehand. Processes in which only readily soluble carrier materials such as sugar, starch and cellulose ether are used as binders for the production of enzyme preparations are also bound to this requirement.

Enzyme granules are known from the European patent EP 168 526 which contain starch, zeolite and water-soluble granulation aid which are swellable in water. In this document, a manufacturing process for such formulations is proposed which essentially consists of concentrating a fermenter solution freed from insoluble constituents, adding the additives mentioned and granulating the resulting mixture. The process with the additive mixture proposed there is advantageously carried out with fermentation solutions which have been concentrated to a relatively high dry matter content, for example 55% by weight. In addition, the granules produced in this way have a high dissolution or disintegration rate under washing conditions, so that the enzymes can be deactivated relatively quickly under certain circumstances.

It was therefore an object to improve the powder properties, in particular the uniform solubility of the known products, to further reduce the loss of activity during enzyme processing and to further increase the shelf life of the enzymes by a production process which allows the use of low-concentration fermentation broths. This object is achieved by the invention described below.

The invention relates to enzyme granules suitable for incorporation in detergents and cleaning agents and having a grain size of 0.1 mm to 2 mm, containing 2% by weight to 20% by weight of protease, amylase and / or cellulase, calculated as dry matter, 10% by weight to 50% by weight of swellable starch, 5% by weight to 50% by weight of granulating aid, which is a water-soluble organic Polymer contains not more than 10% by weight of water-soluble salt and 3% by weight to 12% by weight of water, which is characterized in that it contains 10% by weight to 35% by weight of cereal flour, and its use for the production of granular detergents and cleaning agents.

The invention further relates to a method for producing such an enzyme granulate by extruding an enzyme premix obtained by mixing an insoluble constituent and concentrating the fermentation broth with additives, spheronizing the extrudate in a rounding machine, drying and optionally applying a dye or pigment-containing coating from water-soluble , film-forming polymer, the process being characterized in that the insoluble constituents are removed from the fermentation broth by microfiltration and the concentrated fermentation broth is mixed with an additive which comprises 10% by weight to 35% by weight of cereal flour, based on the finished granulate, contains.

The primary enzymes that can be used are the proteases, lipases, amylases and / or cellulases obtained from microorganisms such as bacteria or fungi, proteases produced by Bacillus species and their mixtures with amylases being preferred. They are obtained in a known manner by fermentation processes from suitable microorganisms, which are described, for example, in German patent applications DE 19 40 488, DE 20 44 161, DE 22 01 803 and DE 21 21 397, US Pat. Nos. 3,632,957 and US 4,264,738 and European patent application EP 006 638. The process according to the invention can be used particularly advantageously for the formulation of the very active proteases of the so-called second generation, which include, for example, Savinase ^(R) and enzymes known from international patent application WO 91/2792, their storage-stable incorporation into washing and cleaning agents as a rule Problems. According to the invention, it is possible to convert the broths of extracellular enzymes obtained in the fermentation processes immediately after separation of the insoluble accompanying substances by microfiltration and subsequent concentration by ultrafiltration and, if appropriate, subsequent evaporation in vacuo, into storage-stable, largely odorless granules. The formation of unwanted enzyme dusts and the loss of activity associated with additional drying processes is avoided.

Enzymes are preferably contained in the granules according to the invention in amounts of 4% by weight to 20% by weight. If the enzyme granulate according to the invention is a protease-containing formulation, the protease activity is preferably 70,000 protease units (PE, determined according to the method described in surfactants 7 (1970), 125) to 250,000 PE, in particular 140,000 PE to 200,000 PE , per gram of enzyme granules.

The starch which is swellable in water is preferably corn starch, rice starch, potato starch or mixtures thereof, the use of corn starch being particularly preferred. Swellable starch is contained in the enzyme granules according to the invention in amounts of from 10% by weight to 50% by weight, in particular from 20% by weight to 40% by weight, the sum of the amounts of the swellable starch and the flour preferably not is over 60% by weight, in particular 32% by weight to 55% by weight.

The cereal flour suitable according to the invention is in particular a product which can be produced from wheat, rye, barley or oats or a mixture of these flours, wholemeal flours being preferred. A wholemeal flour is understood in the context of the invention to mean a flour that has not been fully ground, which has been produced from whole, unpeeled grains or at least predominantly consists of such a product, the rest consisting of fully ground flour or starch. Commercial wheat flour qualities, such as Type 450 or Type 550, are preferably used. It is also possible to use flour products from the cereals leading to the aforementioned swellable starches, provided that care is taken to ensure that the flours have been produced from the whole grains. The flour component of the additive mixture results in a substantial reduction in the odor of the enzyme preparation, which far exceeds the reduction in odor by incorporating the same amounts of corresponding starch types. Such cereal flour is contained in the enzyme granules according to the invention in amounts from 10% by weight to 35% by weight, in particular from 12% by weight to 25% by weight.

Furthermore, the enzyme granules according to the invention contain 5% by weight to 50% by weight, preferably 15% by weight to 25% by weight, of granulation aid which contains at least one water-soluble organic polymer. Suitable compounds of this class are, for example, cellulose and starch ethers, such as carboxymethyl cellulose, carboxymethyl starch, methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose and corresponding cellulose mixed ethers. Optionally, gelatin, casein, tragacanth, maltodextrose, sucrose, invert sugar, glucose syrup or other water-soluble or readily dispersible oligomers or polymers of natural origin can also be used. Usable synthetic water-soluble polymers are polyethylene glycol, polyacrylates, polymethacrylates, copolymers of acrylic acid with maleic acid or compounds containing vinyl groups, furthermore polyvinyl alcohol, partially saponified polyvinyl acetate and polyvinylpyrrolidone. Insofar as the aforementioned compounds are those with free carboxyl groups, they are normally in the form of their sodium salts.

In addition, the enzyme granules can contain water-insoluble granulation aids, which include, in particular, cellulose and layered silicates, for example bentonites or smectites.

Combinations of 8% by weight to 20% by weight of sodium carboxymethyl cellulose and 3% by weight to 10% by weight of polyethylene glycol have proven to be particularly suitable, the latter having a molecular weight of preferably 1000 to 20,000, in particular 2000 to 15 000 has. Sodium carboxymethyl cellulose reduces the rate of disintegration and dispersion of the granules in cold wash liquors. By adding polyethylene glycol, this effect can be changed in the direction of a higher dissolution rate. At the same time, this addition facilitates spheronization of the granules. As an additional granulation aid, the granulate according to the invention can be a combination of preferably 2% by weight to 10% by weight of cellulose and preferably 2% by weight to 3% by weight of sucrose or a combination of preferably 2% by weight to 10% by weight .-% cellulose and preferably 2 wt .-% to 5 wt .-% of a compound selected from the group comprising sorbitol, maltodextrin, polyvinylpyrrolidone, amylogum and mixtures thereof.

As further constituents, the granules can also contain small amounts, preferably not more than 10% by weight, in particular 1% by weight to 10% by weight, of water-soluble salts which are selected such that they do not adversely affect the shelf life of the enzymes influence. These salts can increase the rate of disintegration and dispersion of the granules, especially in cold wash liquors. Suitable salts are, for example, sodium chloride, sodium sulfate, sodium acetate, potassium acetate or mixtures thereof.

For the production of the enzyme granules according to the invention, fermentation broths are used which are freed from insoluble accompanying substances by microfiltration. The microfiltration is preferably carried out as cross-flow microfiltration using porous tubes with micropores larger than 0.1 »m, flow rates of the concentrate solution of more than 2 m / s and a pressure difference to the permeate side of less than 5 bar, as for example in the European patent application EP 200 032. The microfiltration permeate is then concentrated, preferably by ultrafiltration, if appropriate with subsequent vacuum evaporation. A particular advantage of the invention is that the concentration can be carried out in such a way that only relatively low dry matter contents of preferably 5% by weight to 50% by weight, in particular 10% by weight to 40% % By weight. The concentrate is metered into a suitably previously prepared dry, powdery to granular mixture of the additives described above. The water content of the mixture should be selected so that it can be converted into granular particles which do not stick at room temperature when processed with stirring and striking tools and plastically deformed and extruded when using higher pressures.

The free-flowing premix is, in principle, subsequently processed in a kneader and a connected extruder to form a plastic mass, the result of the mechanical processing being the temperature of between 40 ° C. and 60 ° C., in particular 45 ° C. to 55 ° C. can heat. The material leaving the extruder is passed through a perforated disc with a subsequent knock-off knife and is thereby crushed into cylindrical particles of a defined size. The expedient is Diameter of the holes in the perforated disc 0.4 mm to 1 mm, preferably 0.5 mm to 0.9 mm. The particles present in this form can then be dried and used for later use. However, it has proven advantageous to subsequently spheronize the cylindrical particles leaving the extruder and chopper, ie to round them off and deburr them in suitable devices. Such a spheronization method is described, for example, in the German design documents DE 21 37 042 and DE 21 37 043. For this purpose, a device is used which consists of a cylindrical container with stationary, fixed side walls and a friction plate rotatably mounted on the bottom. Devices of this type are commonly known in the art under the Marumerizer ^{(R) name} .

After spheronization, the still moist spheres are continuously or batchwise, preferably using a fluidized bed drying unit, preferably at a maximum of 45 ° C., in particular a maximum of 40 ° C., product temperature up to a residual moisture content of 3% by weight to 12% by weight. preferably 6% to 8% by weight dried. After or preferably during drying, additional substances can be introduced to coat and coat the particles. Suitable coating materials are, in particular, the film formers among the aforementioned water-soluble organic polymers, preferably higher molecular weight, that is to say a polyethylene glycol having a molecular weight of 1,000 to 20,000. Furthermore, dyes or pigments can also be applied to the particles at this stage in order to cover or change any inherent color, which usually results from the enzyme concentrate. Titanium dioxide, which is preferably introduced in an aqueous dispersion, has proven particularly useful as an inert and physiologically acceptable pigment. The water supplied via the pigment dispersion or via the polymer solution is removed again when drying is carried out at the same time or is subsequently required again.

Any dusty particles with a grain size of less than 0.1 mm, preferably less than 0.2 mm and any coarse particles with a grain size of more than 2 mm, preferably more than 1.6 mm, can be removed by sieving or air sifting and possibly returned to the manufacturing process become. The granules according to the invention preferably contain less than 5% by weight, in particular at most 1% by weight, of particles with grain sizes outside the range from 0.2 mm to 1.6 mm.

The enzyme preparation obtained consists of largely rounded, dust-free particles which generally have a bulk density of about 500 to 900 grams per liter, in particular 650 to 880 grams per liter. It is preferably used for the production of solid, especially granular detergents or cleaning agents. When using protease-containing fermenter broths, their enzyme activity can range from preferably 70,000 to 250,000 protease units per gram (PE / g), in particular from 140,000 to, due to the flexible dry matter content of the broths before mixing with the additives 200,000 PE / g. The granules according to the invention are notable for their low intrinsic odor and, even when mixed with detergents and cleaning agents and per compounds, for very high storage stability, in particular at temperatures above room temperature and high atmospheric humidity, and for uniform dissolution behavior in the wash liquor. A further advantage is that the enzyme granules according to the invention release in water at 25 ° C. preferably not more than 90% of their enzyme activity within 2 minutes and preferably more than 97% within 5 minutes and thus a sufficiently long exposure time of the enzyme to enzymatically removable Ensure soiling, especially in aqueous washing or cleaning solutions.

Examples example 1

By fermentation of the method described in the international patent application WO 91/2792 by transforming a gene sequence from Bacillus lentus DSM 5483 modified Bacillus licheniformis (ATCC 53926) analogously to the method given in the German patent DE 29 25 427, 3.3 m³ of a biomass were obtained Obtain fermenter broth containing about 50,000 protease units per gram (PE / g). The pH of the fermenter broth was adjusted to approximately 7.5 by adding 33% by weight CaCl₂ solution. Then coarse contaminants were removed by decanting. The broth was diluted with water to a volume of 11.5 m³. The enzyme was separated from the cell mass by means of cross-flow microfiltration (membrane pore diameter 0.14 »m). About 24 m³ microfiltration permeate with about 7 000 PE / g was obtained. Ultrafiltation (cut-off limit at molecular weight 10,000) of the enzyme-containing filtrate and subsequent evaporation in vacuo (50 mbar, temperature up to 30 ° C.) gave 0.3 m 3 of an F1 broth with a dry matter content of 35% by weight and a protease content of 500,000 PE / g. Using the same procedure, broths F2 (28% by weight dry matter, 480,000 PE / g), F3 (19% by weight dry matter, 350,000 PE / g) and F4 (38% by weight dry matter) were made from similar fermenter broths. 600 000 PE / g) obtained. The fermenter broths F1 to F4 thus concentrated were mixed in a mixer equipped with a rotating impact tool with the additives listed in Table 1 and homogenized in a kneader provided with external cooling. The plastic materials were extruded using an extruder equipped with a perforated disc (0.7 mm hole diameter) and a rotating knife. The extrudates E1 to E5 characterized by their composition in Table 1 were obtained with lengths of 0.7 mm to 1 mm, which were processed in a spheronizing device (Marumerizer ^(R) ) for a processing time of about 5 minutes with simultaneous dusting with powdered calcium carbonate (3 % By weight) were shaped into rounded particles and deburred. The material leaving the spheronizer was brought to a water content in a fluidized bed dryer at temperatures from 40 ° C. to 45 ° C. in about 15 minutes of about 6% by weight. Subsequent sieving largely removed particles with particle sizes below 0.2 mm and above 1.6 mm, which were returned to the process at the stage of mixing with the additives. The enzyme granules were coated by spraying on an aqueous titanium dioxide pigment suspension and then spraying on an aqueous polyethylene glycol solution during the fluidized-bed drying. The end products G1 to G5 with the enzyme activities given in Table 2 were thus obtained from the extrudates E1 to E5 . Table 1 Composition of the extrudates [% by weight] E1 E2 E3 E4 E5 F1 29.0 27.5 - - - F2 - - 28.0 - - F3 - - - 20.0 - F4 - - - - 30.0 Wheat flour type 450 13.0 20.0 25.0 12.8 20.0 Sucrose 2.5 2.5 2.5 3.0 2.5 Cornstarch 29.2 23.0 23.2 38.2 21.5 Sodium acetate 1.0 1.0 1.0 2.0 1.0 Cellulose powder ^a) 3.3 3.0 3.3 3.0 3.0 Carboxymethyl cellulose ^b) 15.0 17.0 12.0 15.0 17.0 Polyethylene glycol ^c) 7.0 6.0 5.0 6.0 5.0 ^a) : Technocel ^(R) 30 (manufacturer cellulose filler factory) ^b) : Tylose ^(R) CR 1500 (manufacturer Hoechst) ^c) : Average molecular weight 2000

Table 2 Enzyme activity of the granules [PE / g] granules made from extrudate Enzyme activity [PE / g] G1 E1 145,000 G2 E2 137,500 G3 E3 134 400 G4 E4 70,000 G5 E5 180,000

Example 2

As described in EP 168 526, 1 gram of enzyme granules in 100 ml of water at 16 ° dH (160 mg CaO / l) stirred with a magnetic stirrer was added at 25 ° C. to determine the dissolution rate. Samples were taken after every 1 minute and their enzyme activity determined after filtering off undissolved constituents. The ranges given in Table 3 resulted from 3 determinations, the dissolution rates of the granules G1 to G5 produced according to Example 1 did not differ significantly. Table 3 Rate of enzyme release Time [minutes] released activity [%] 1 60-70 2nd 83-86 3rd 93-97 5 100

Example 3

2 grams of the enzyme granules G2 were mixed with 98 grams of a commercial heavy-duty detergent (perborate content 18% by weight) and stored in a cardboard container made of non-laminated cardboard at 30 ° C. and 80% relative atmospheric humidity. For comparison, a sample which contained the same amount of commercially available granules of an alkaline protease (Savinase ^(R) 4.0 T, manufacturer Novo Industri A / S) was stored under the same conditions. After storage periods of 2 and 4 weeks, the samples had the enzyme activities given in Table 4 (based on activity used = 100%). The activity of the further enzyme granules according to the invention according to Example 1 did not differ significantly from that of the granules G2 after storage. The washing performance of the G2- containing detergent against protein-containing stains was in no way inferior to that of the comparative detergent. Table 4 Storage stability in a detergent formulation (30 ° C, 80% relative humidity) Storage period [weeks] Activity [Rel .-%] G2 comparison 2nd 85 60 4th 77 26

Claims (14)

1. Enzyme granules suitable for incorporation in detergents with a particle size of 0.1 mm to 2 mm and containing 2% by weight to 20% by weight protease, lipase, amylase and/or cellulase, expressed as dry matter, 10% by weight to 50% by weight swellable starch, 5% by weight to 50% by weight of a granulation aid containing a water-soluble organic polymer, not more than 10% by weight water-soluble salt and 3% by weight to 12% by weight water, characterized in that the enzyme granules contain 10% by weight to 35% by weight cereal flour.
2. Enzyme granules as claimed in claim 1, characterized in that they contain 4% by weight to 20% by weight protease, lipase, amylase and/or cellulase, more especially protease, 20% by weight to 40% by weight swellable starch, more especially rice starch, 15% by weight to 40% by weight granulation aid and 12% by weight to 25% by weight cereal flour, the sum total of the quantities of swellable starch and flour being no more than 60% by weight and, more particularly, between 32% by weight and 55% by weight.
3. Enzyme granules as claimed in claim 1 or 2, characterized in that the flour is selected from the group consisting of wheat flour, rye flour, barley flour, oat flour and mixtures thereof.
4. Enzyme granules as claimed in any of claims 1 to 3, characterized in that they contain protease having an activity of 70,000 PU to 250,000 PU and, more particularly, 140,000 PU to 200,000 PU per gram enzyme granules.
5. Enzyme granules as claimed in any of claims 1 to 4, characterized in that they contain 8% by weight to 20% by weight carboxymethyl cellulose and 3% by weight to 10% by weight polyethylene glycol having an average molecular weight of 1000 to 20,000 as the granulation aid.
6. Enzyme granules as claimed in claim 5, characterized in that they contain a combination of 2% by weight to 10% by weight cellulose and 2% by weight to 3% by weight sucrose or a combination of 2% by weight to 10% by weight cellulose and 2% to 5% by weight of a compound selected from the group consisting of sorbitol, maltodextrin, polyvinyl pyrrolidone, amylogum and mixtures thereof as the additional granulation aid.
7. Enzyme granules as claimed in claim 5 or 6, characterized in that they contain no more than 10% by weight layer silicate as the additional granulation aid, the sum total of the quantities of layer silicate and carboxymethyl cellulose not exceeding 20% by weight.
8. Enzyme granules as claimed in any of claims 1 to 7, characterized in that they contain 1% by weight to 3% by weight of a water-soluble salt containing an alkali metal chloride, an alkali metal sulfate, an alkali metal acetate or a mixture thereof.
9. Enzyme granules as claimed in any of claims 1 to 8, characterized in that they are coated with a dye- or pigment-containing coating of water-soluble film-forming polymer.
10. Enzyme granules as claimed in any of claims 1 to 9, characterized in that they contain less than 5% by weight and preferably at most 1% by weight particles having particle sizes outside the 0.2 mm to 1.6 mm range.
11. Enzyme granules as claimed in any of claims 1 to 10, characterized in that they release no more than 90% of their enzyme activity in 2 minutes and more than 95% of their enzyme activity in 5 minutes in water at 25°C.
12. A process for the production of enzyme granules with a particle size of 0.1 mm to 2 mm and containing 2% by weight to 20% by weight protease, lipase, amylase and/or cellulase, expressed as dry matter, 10% by weight to 50% by weight swellable starch, 5% by weight to 50% by weight of a granulation aid containing a water-soluble organic polymer, 3% by weight to 12% by weight water and not more than 10% by weight water-soluble salt by extruding an enzyme premix prepared by mixing a fermentation broth freed from insoluble constituents and concentrated with additives, spheronizing the extrudate in a spheronizer, drying and optionally applying a dye- or pigment-containing coating of water-soluble film-forming polymer, characterized in that the insoluble constituents are removed from the fermentation broth by microfiltration and the concentrated fermentation broth is mixed with an additive containing 10% by weight to 35% by weight cereal flour, based on the final granules.
13. A process as claimed in claim 12, characterized in that the flour is selected from the group consisting of wheat flour, rye flour, barley flour, oat flour and mixtures thereof.
14. The use of the enzyme granules claimed in any of claims 1 to 11 for the production of solid, more particularly granular, detergents and cleaning products.