EP-4739761-A1 - ENZYMATIC DETERGENT BARS HAVING IMPROVED ENZYME STABILITY

Abstract

The invention provides enzymatic detergent bars exhibiting improved enzyme stability after repeated wetting and drying when used for hand washing of laundry or dishware.

Inventors

• SIMONSEN, OLE
• Ramani, Shilpa
• Doneria, Sanjoli
• SAINATHAN, Rajendra, Kulothungan
• JAIN, PRASHANT
• Subramaniam, Ramya
• S. CHIGADANNAVAR, Premchand

Assignees

• Novozymes A/S

Dates

Publication Date

20260513

Application Date

20240703

Claims (15)

1. 1 . A solid detergent bar comprising (a) an anionic surfactant selected from the group consisting of alkyl sulfonic acids, alkyl sulfates, alkyl sulfonates, alkyl benzene sulfonic acid, alkyl benzene sulfates, alkyl benzene sulfonates, alkyl ether sulfonic acids, alkyl ether sulfates, alkyl ether sulfonates, paraffin sulfonic acids, paraffin sulfates, paraffin sulfonates, olefin sulfonic acids, olefin sulfates, olefin sulfonates, alpha-sulfocarboxylates, esters of alpha-sulfocarboxylates, alkyl glyceryl ether sulfonic acids, alkyl glyceryl ether sulfates, alkyl glyceryl ether sulfonates, sulfates of fatty acids, sulfonates of fatty acids, sulfonates of fatty acid esters, alkyl phenol polyethoxy ether sulfates, 2-acryloxy- alkane-l-sulfonic acid, 2-acryloxy-alkane-l -sulfonate, beta-alkyloxy alkane sulfonic acid, betaalkyloxy alkane sulfonate, and salts and mixtures thereof; (b) a builder; (c) water; and (d) an enzyme-containing granule having a hydrophobic coating.
2. 2. The detergent bar of claim 1 , which is free of bleaching agents selected from the group consisting of bleach catalysts, bleach activators, and sources of organic peroxyacids.
3. 3. The detergent bar of any of the preceding claims, which comprises 5-30% w/w of the anionic surfactant; preferably 5-20% w/w of the anionic surfactant.
4. 4. The detergent bar of any of the preceding claims, which further comprises a non-ionic surfactant; preferably in an amount of 1-10% w/w.
5. 5. The detergent bar of any of the preceding claims, which comprises 10-40% w/w of the builder; preferably the builder is selected from the group consisting of hydratable alkali metal phosphates, carbonates, bicarbonates, zeolites, ethylenediaminetetraacetate, nitrilotriacetate, and mixtures thereof.
6. 6. The detergent bar of any of the preceding claims, which comprises 10-30% w/w of water.
7. 7. The detergent bar of any of the preceding claims, which comprises 0.01-5% w/w of the enzyme-containing granule having a hydrophobic coating.
8. 8. The detergent bar of any of the preceding claims, wherein the hydrophobic coating comprises an oil, fat, wax, or paraffin; such as a vegetable oil or fat.
9. 9. The detergent bar of any of the preceding claims, wherein the hydrophobic coating comprises a vegetable oil or fat, which is a mono-, di- or triglyceride, or a mixture thereof; such as hydrogenated palm oil, hydrogenated palm kernel oil, or hydrogenated soya bean oil.
10. 10. The detergent bar of any of the preceding claims, wherein the hydrophobic coating comprises an oil, fat, wax, or paraffin having a melting point in the range of 30-100°C; preferably in the range of 40-60°C.
11. 11. The detergent bar of any of the preceding claims, wherein the hydrophobic coating comprises 25-80% w/w, preferably 40-80% w/w, of fine particulate matter having an average volume based particle size, Dso, of less than 50 pm; preferably the fine particulate matter comprises talc, kaolin, titanium dioxide, calcium carbonate, calcium sulphate, starch, diatomaceous earth, amorphous silica, bentonite, or mixtures thereof.
12. 12. The detergent bar of any of the preceding claims, wherein the enzyme is selected from the group consisting of protease, amylase, carbohydrase, lipase, nuclease, oxidoreductase, and combinations thereof; preferably the enzyme is protease or amylase.
13. 13. The detergent bar of any of the preceding claims, wherein the granule comprises 0.5-25% w/w of active enzyme protein; preferably 1-20% w/w of active enzyme protein.
14. 14. A method of making the detergent bar of any of the preceding claims, comprising (a) mixing a surfactant; a builder; water, and enzyme-containing granules having a hydrophobic coating, (b) milling the mixture, and (c) extruding the milled mixture.
15. 15. The method of the preceding claim, wherein the surfactant, builder, and water are premixed before adding the enzyme-containing granules having a hydrophobic coating.

Description

ENZYMATIC DETERGENT BARS HAVING IMPROVED ENZYME STABILITY FIELD OF THE INVENTION The present invention relates to detergent bars comprising enzyme granules with a hydrophobic coating, which exhibit improved enzyme stability during repeated wetting and drying. Such detergent bars are useful for hand washing of laundry or dishware. BACKGROUND Detergent bars are more common in emerging markets where body grime and tough stains are still consumer pain points. Unlike detergent powders and liquids, laundry and dishwash bars are still whitespace for enzyme inclusion. The basic wash practice in case of bars is to wet and use, contrary to detergent powders and liquid, resulting in repeated wetting and drying cycles. Detergent bars are also referred to as syndet bars (or non-soap bars) and distinguish from soap bars by containing synthetic surfactant, while soap bars contain natural soaps (sodium salts of fatty acids) made by saponification. Enzymes can be added to detergent bars in the form of a liquid enzyme product, or as a granulated enzyme product, which dissolves and releases the enzyme during use. Granulated enzymes have excellent stability during manufacture and storage, but when the granules dissolve during wet-dry cycle, the protection is lost, and the enzyme activity will decline. Because of how detergent bars are used, enzyme granules in the outer layers of the detergent bar will fully or partly dissolve during rubbing of the bar on the fabric in the washing process, resulting in loss of enzyme stability during the following storage until the next wash cycle. We have found that enzyme granules become more resistant to the repeated wetting and drying cycles by adding a coating that does not dissolve in water, but which releases the enzyme during the rubbing phase in the washing process. SUMMARY OF THE INVENTION The present invention provides, in a first aspect, a detergent bar comprising an anionic surfactant, a builder, water, and an enzyme-containing granule having a hydrophobic coating. Other aspects and embodiments of the invention are apparent from the description and examples. Unless otherwise indicated, or if it is apparent from the context that something else is meant, all percentages are percentage by weight (% w/w). As used herein, the term "consists essentially of" (and grammatical variants thereof), as applied to the compositions and methods of the invention, means that the compositions/methods may contain additional components so long as the additional components do not materially alter the composition/method. As used herein, the term "essentially free of' (and grammatical variants thereof), as applied to the compositions and methods of the invention, means that the compositions/methods may contain minor amounts of the specified component so long as the amount of the component does not materially alter, or provide any material effect on, the composition/method. In an embodiment, "essentially free of" means 0% w/w. Particle size distribution may be measured using laser diffraction methods or optical digital imaging methods or sieve analysis. Unless otherwise indicated, the particle size is the volume based particle diameter (and the average particle size, Dso, is the volume average particle diameter), which is the same as the weight based particle diameter if the densities of the particles are the same DETAILED DESCRIPTION We have found that it is advantageous to apply a hydrophobic coating to enzyme granules used in detergent bars. Enzyme granules located below the surface of a detergent bar will experience a wet/humid environment during use, and this is detrimental to the structural stability of detergent enzyme granules designed to quickly dissolve in water. By applying a hydrophobic coating, the enzyme granules will be more resistant to dissolution and only break after application of the mechanical action associated with the washing process. The present invention is particularly useful in the production of (syndet) detergent bars because such detergent bars require a lower temperature in the manufacturing process than soap bars. This provides for a better enzyme stability during manufacturing and avoids melting of the hydrophobic coating, in particular hydrophobic coatings made from vegetable oils or fats. Detergent bars The present invention relates to a (syndet) detergent bar comprising enzyme granules having a hydrophobic coating, as described below. In particular, the present invention relates to a detergent bar comprising an (synthetic) anionic surfactant, a builder, water, and enzyme granules having a hydrophobic coating; where the anionic surfactant is selected from the group consisting of alkyl sulfonic acids, alkyl sulfates, alkyl sulfonates, alkyl benzene sulfonic acid, alkyl benzene sulfates, alkyl benzene sulfonates, alkyl ether sulfonic acids, alkyl ether sulfates, alkyl ether sulfonates, paraffin sulfonic acids, paraffin sulfates, paraffin sulfonates, olefin sulfonic acids,