WO2012101149A1

WO2012101149A1 - Storage-stable enzyme granules

Info

Publication number: WO2012101149A1
Application number: PCT/EP2012/051097
Authority: WO
Inventors: Ole Simonsen; Dennis BONNÉ
Original assignee: Novozymes AS
Current assignee: Novozymes AS
Priority date: 2011-01-26
Filing date: 2012-01-25
Publication date: 2012-08-02
Anticipated expiration: 2013-07-26

Abstract

The storage stability of enzyme granules in bleach-containing granulates such as detergents or detergent additives can be improved by applying a coating which includes malic acid.

Description

STORAGE-STABLE ENZYME GRANULES

FIELD OF THE INVENTION

The present invention relates to an enzyme-containing granule and to a bleach- containing granular composition comprising the granules.

BACKGROUND OF THE INVENTION

Enzyme-containing granules are commonly added to bleach-containing granular compositions such as detergents or detergent additives. The bleach tends to lower the stability of the enzyme during storage, so there is a need to improve the storage stability of enzyme granules in this environment.

WO 00/63336 discloses enzyme composite particles having an acidic barrier and a physical barrier coating.

WO 2004/067739 discloses that the stability of coated enzyme granules in hostile alkaline powder detergents can be improved by adding acidic buffer components to the granules; optionally the coating of the granule may also contain an acidic buffer.

WO 00/01793 discloses a new improved enzyme coating granule.

WO 87/07292 discloses coated detergent enzymes.

SUMMARY OF THE INVENTION

The inventors have found that the storage stability of enzyme granules in bleach- containing powders such as detergents or detergent additives can be improved by applying a coating which includes malic acid.

Accordingly, the invention provides a granule comprising a core surrounded by a protective coating, wherein:

a) the core comprises an enzyme, and

b) the coating comprises malic acid.

The invention also provides a granular composition comprising (a) the above particles and (b) particles comprising a bleach.

DETAILED DESCRIPTION OF THE INVENTION Malic acid coating

The granule of the invention comprises a core surrounded by a protective coating. The core comprises an enzyme, and the protective coating comprises malic acid, typically in an amount of 2-20 % by weight of the coating. The malic acid coating may comprise malic acid in an amount of more than 80% by weight, e.g. more than 90% or more than 95%. Alternatively, the malic acid coating may include a salt, typically in an amount above 60%, particularly 80-98 %, by weight of the coating. The salt is preferably water soluble, with a solubility at 20°C of at least 0.1 g per 100 g of water, particu- larly at least 10 g per 100 g. The salt may be sodium sulfate (particularly in anhydrous form) or another salt described in WO 00/01793.

The malic acid is typically present in an amount of 0.2-10 % by weight of the core, particularly 0.3-5% or 0.5-3%. The malic acid coating typically constitutes 10-40 % by weight of the core.

Optional second coating

Optionally, the malic acid coating may be surrounded by one or more additional coatings, e.g. comprising a wax, particularly polyethylene glycol (PEG) or polyvinyl alcohol (PVA). The PEG typically has a molecular weight of 3000-6000.

The malic acid coating and/or the optional second coating may comprise a filler or pigment, particularly kaolin, titanium dioxide or talc. The total amount of fillers and pigments typically constitutes 5-20 % by weight of the total amount of the coatings.

Enzyme-containing core

The invention may be used to improve the storage stability of any enzyme, particularly a bleach-sensitive detergent enzyme. Examples are proteases, amylases, lipases, carboydras- es and cellulases.

The protease may be a subtilisin, particularly an alkaline microbial serine protease. Examples are subtilisins derived from Bacillus, e.g., subtilisin Novo, subtilisin Carlsberg, subtilisin ΒΡΝ', subtilisin 309, subtilisin 147 and subtilisin 168 (described in WO 89/06279).

The content of enzyme (calculated as pure enzyme protein) in the granule will typically be in the range of from about 0.5% to 20% by weight of the core. The core may be prepared by various known methods, e.g. as described in US 4, 106,991 , WO 97/23606 or WO 97/391 16.

The core may consist of an inert particle with the blend absorbed into it, or with the blend applied on to the surface e.g. via fluid bed coating.

The core particle may have a diameter of 20-2000 μνη, particularly 50-1500 μνη, 100-1500 μιη or 250-1200 m. Method of applying coating

The malic acid coating (optionally comprising salt) may be applied onto the enzyme core by atomization of a solution of the compounds onto the core granules in a fluid bed, the malic acid coating may further be applied in vacuum mixers, dragee type coaters (pan-drum coaters), equipment for coating of seeds, equip-ment comprising rotating bottoms (eks. Roto Glatt, CF granulators (Freund), torbed processors (Gauda) or in rotating fluid bed processors such as Omnitex (Nara).

After applying the malic acid layer, the granule may optionally be dried. The drying of the malic acid coated granule can be achieved by any drying method available to the skilled person, such as spray-drying, freeze drying, vacuum drying, fluid bed drying, pan drum coating and microwave drying. Drying of the malic acid coated granule can also be combined with granulation methods which comprise e.g. the use of a fluid bed, a fluid bed spray dryer (FSD) or a Multi-stage dryer (MSD).

The coating should encapsulate the core unit by forming a substantially continuous layer. A substantially continuous layer is to be understood in the present invention as a coating having few or none holes, so that the core unit it is encapsulating has few or none uncoated areas. The layer or coating should in particular be homogenous in thickness.

Bleach-containing granular composition

The granules are particularly suited for incorporation in a granular detergent composi- tion comprising a surfactant. Enzyme granules according to the invention result in improved storage stability of the enzyme when the granules are incorporated in a detergent, even a detergent comprising aggressive components such as a bleaching system.

The detergent composition may for example be formulated as a laundry detergent composition for hand or machine washings including a cleaning additive composition suitable for pre-treatment of stained fabrics or a fabric softener composition, or a detergent composition for use in general household hard surface cleaning operations, or a composition for hand or machine dishwashing operations.

The detergent composition of the invention may be in any convenient dry form, e.g., a bar, a tablet, a powder, a granulate or a paste.

The granules show improved storage stability when added to a bleach-containing powder (or granular) composition. The bleach is typically a peroxide-based bleaching system such as a percarbonate or a perborate, which may be combined with a peracid-forming bleach activator such as tetraacetylethylenediamine (TAED) or nonanoyloxybenzenesulfonate (NOBS).

The bleach-containing powder or granular composition may be a detergent additive comprising at least 50 % by weight of the bleach, or it may be a detergent comprising 5-25 % by weight of surfactant and 10-25 % by weight of the bleach.

Suitable bleaching system components include bleach activators, sources of hydrogen peroxide such as sodium percarbonate and sodium perborates, preformed peracids and mixtures thereof. Suitable preformed peracids include peroxycarboxylic acids and salts, percarbonic acids and salts, perimidic acids and salts, peroxymonosulfuric acids and salts, for example, Oxone®. Examples of bleaching systems include peroxide-based bleaching systems, which may comprise, for example, an inorganic salt, including alkali metal salts such as sodium salts of per-borate (usually mono- or tetra-hydrate), percarbonate, persulfate, perphosphate, persili- cate salts, in combination with a peracid-forming bleach activator. Suitable bleach activators in- el u d e 4-(dodecanoyloxy)benzenesulfonate (LOBS), 4-(decanoyloxy)benzenesulfonate, 4- (decanoyloxy)benzoate (DOBS), 4-(3,5,5-trimethylhexanoyloxy)benzenesulfonate (ISONOBS), tetraacetylethylenediamine (TAED) and 4-(nonanoyloxy)benzenesulfonate (NOBS), and/or those disclosed in W098/17767. Alternatively, the bleaching system may comprise peroxyacids of, for example, the amide, imide, or sulfone type. The bleaching system may also comprise pe- racids such as 6-(phthaloylamino)percapronic acid (PAP). The bleaching system may also include a bleach catalyst.

The bleach-containing composition may be formulated as described in EP2380481 , WO201 1133380, US201 1212874, US201 1207646, WO2011060109, WO2011005623, WO201 1005630, WO2011005827, WO201 1005833, WO2011005905, WO201 1005910, WO201 1002759, WO2011005813, WO201 1002640, WO2010090915, WO2010006861 , WO2009092699, WO2009030600, WO2009016123, WO201 1036146, WO201 1009887, WO2010142538, WO2010108787, WO2010108783, WO2010108782, WO2010108784, WO2010105961 , WO2010105962, WO2010084203, WO2010063688, DE102009033248, or WO2010049187. EXAMPLES

Example 1 :

An uncoated protease-containing granulate was produced in full scale production equipment after the principles described in U.S. Pat. No. 4,106,991 example 1 with the following exceptions:

· Sodium sulfate was used instead of sodium chloride

The enzyme concentrate was an aqueous solution of the protease (Everlase) also containing a carbohydrate (dextrin) binder

The uncoated granulate was sieved between 300 and 1200 microns:

Granulate A (comparative granulate):

5.0 kg of the uncoated granulate was loaded into a top spray fluid bed (Niro MP-1). The following mixture was coated onto the granulate:

1000 g sodium sulfate

100 g TiO2

3000 g water (kept at 40-50°C) After coating the salt onto the granulates a thin film coating was applied:

60 g PEG4000 (polyethylene glycol)

60 g Kaolin

180 g water

Granulate B (granulate of the invention):

950 g sodium sulfate

50 g Malic acid

100 g TiO2

3000 g water (kept at 40-50°C)

After coating the salt onto the granulates a thin film coating was applied:

60 g PEG4000 (polyethylene glycol)

60 g Kaolin

180 g water

The following bed settings were used during coating of granulate A and B:

Air flow: 175 kg/h

Inlet air temperature: 90°C during salt coating, 60°C during film coating Product temperature: 42-46°C during salt coating, 40-42°C during film coating 1.2 mm nozzle

3.0 bar nozzle pressure

After salt coating the granulate was dried to a temperature of approx. 60°C, after film coating the granulate was dried to a temperature of approx. 50°C and subsequently cooled to approx. 40°C before discharge.

Storage stability:

Granulate A and B were mixed with a commercial bleach-containing powder detergent additive (4% granulate+96% powder additive) without enzyme (Vanish from Reckitt Benckiser). Glasses with 5 g of the enzyme containing detergent additive were stored for 2 weeks at 37°C and 70% relative humidity (%RH) in open glasses. The residual activity of the protease was analyzed using standard protease assays (compared to unstored samples):

% residual enzyme activity

Granulate A (comparative granulate): 71 % Granulate B (granulate of the invention) 89%

The results in this accelerated study show improved storage stability for the granulate with malic acid.

Claims

I . A granule comprising a core surrounded by a protective coating, wherein:

a) the core comprises an enzyme, and

b) the coating comprises malic acid. 2. The granule of claim 1 wherein the malic acid is present in an amount of 0.2-10 % by weight of the core.

3. The granule of claim 1 or 2 wherein the malic acid coating further comprises a salt, particularly in an amount of 80-98% by weight of the coating.

4. The granule of claim 3 wherein the salt is water soluble, particularly sodium sulfate. 5. The granule of any of claims 1-4 wherein the malic acid coating is present in an amount of 10-40 % by weight of the core.

6. The granule of any of claims 1-5 wherein the malic acid coating is surrounded by a second coating comprising a wax, particularly polyethylene glycol or polyvinyl alcohol.

7. The granule of any of claims 1-6 wherein the malic acid coating and/or the optional second coating comprises a filler or pigment, particularly kaolin, titanium dioxide or talc.

8. The granule of any of claims 1-7 wherein the enzyme is a protease, an amylase, a lipase or a cellulase.

9. The granule of claim 8 wherein the protease is a subtilisin, particularly an alkaline microbial serine protease. 10. The granule of any of claims 1-9 which has a particle size of 300-1200 μηι.

I I . The granule of any of claims 1-10, wherein the protective coating constitutes 10-40% by weight of the core, and the coating comprises malic acid in an amount of 2-20% by weight of the coating and sodium sulfate in an amount of 80-98 % by weight of the coating.

12. A granular composition comprising (a) the particles of any of claims 1-11 and (b) particles comprising a bleach.

13. The composition of claim 12 wherein the bleach is an oxygen-based bleach, particularly a percarbonate or perborate. 14. The composition of claim 12 or 13 which is a detergent additive comprising at least 50 % by weight of the bleach.

15. The composition of claim 12 or 13 which is a detergent comprising 5-25 % by weight of surfactant and 10-25 % by weight of the bleach.