WO2011110593A1

WO2011110593A1 - Stabilised enzyme-containing liquid detergent composition

Info

Publication number: WO2011110593A1
Application number: PCT/EP2011/053540
Authority: WO
Inventors: Rupertus Mattias Rafaël GIJSEN; Rudolf Eduard Nijburg; Laurens Johan Hendrik Van Oene
Original assignee: Purac Biochem Bv
Priority date: 2010-03-12
Filing date: 2011-03-09
Publication date: 2011-09-15

Abstract

The present invention pertains to an enzyme-containing liquid detergent composition which comprises water, a surfactant, at least one enzyme, a divalent lactate salt selected from calcium lactate, magnesium lactate, zinc lactate, and combinations thereof, and a monovalent lactate salt selected from sodium lactate, potassium lactate, ammonium lactate, and combinations thereof. It has been found that the combination of the specified monovalent and divalent lactate salts gives good results in the stabilisation of enzymes in liquid detergent compositions.

Description

Stabilised enzyme-containing liquid detergent composition

The present invention pertains to a stabilised enzyme- containing liquid detergent composition . The invention also pertains to a process for stabilising a enzyme-containing liquid detergent composition, and to the use of a specific combination of lactate salts to stabilise enzyme-containing liquid detergent compositions .

Enzyme-containing liquid aetergent compositions are well known in the art . They are mainly intended for the treatment of laundry, although the use of enzyme-containing liquid detergent compositions for dishwashing, whether manually or machine, have also been disclosed. Examples of enzymes used in enzyme-containing liquid detergent compositions are proteases, which are active in the breakdown of protein, and amylases, which are active in the breakdown of starches, Examples of further enzymes are lipases, cellulases,

pectinases, and hemicellulases .

A problem in the field of enzyme-containing liquid detergent compositions is their storage stability over time. It has been found that in enzyme-containing liquid detergent compositions , the activity of the enzymes may decrease over time, which results in a decreased performance of the product .

033,819,523 describes an aqueous enzyme composition, e.g., a surfactant composition which contains a water-soluble calcium salt to stabilise an amylolytic enzyme. It is indicated that the use of a calcium, salt may not be sufficient, and this problem is addressed by incorporating an aliphatic glycol into the composition. GB1278024 describes an aqueous amy.lolytio enzyme-containing detergent composition which is stabilised, by the provision of a calcium salt and an alkali metal thiosulphate .

WO2002/08398 describes stabilisation of an enzyme-containing composition, which may be a detergent composition, using a high level of alkali metal halide salts in combination with a poIyo.1 so.1vent .

WO2008/040818 describes a detergent composition comprising a combination of enzymes and. a calcium ion.

US4, 318, 818 describes a stabilised aqueous enzyme composition containing calcium ions and a low molecular weight carboxylic acid or salt, preferably a formate.

It has been found, however, that there is still need for an improved enzyme-containing liquid detergent composition, which combines high storage stability with ease of

manufacture, low eco-toxicity, and the use. of hie compounds . In the present invention, this problem is solved by the provision of an enzyme-containing liquid detergent

composition which comprises water, a surfactant, at least one enzyme, a divalent lactate salt selected from calcium

lactate, magnesium lactate, zinc lactate, and combinations thereof, and a monovalent lactate salt selected from sodium lactate, potassium lactate, ammonium lactate, and.

combinations thereof.

It has been found that the use of the combination of a divalent lactate salt as specified above and a monovalent lactate salt selected as specified above results in a highly stable enzyme-containing liquid detergent composition. While calcium salts have been described for stabilising enzyme- containing liquid detergent compositions, it was found that the combination of a divalent lactate salt and. a monovalent lactate salt as specified above leads to an improved stability. This is the more surprising since with the

monovalent lactate salt only has limited stabilising activity of itself, The combination of a divalent lactate salt

selected from calcium lactate, magnesium, lactate, zinc lactate, and combinations thereof; and a. monovalent lactate salt selected from sodium lactate, potassium lactate, amm.onium lactate, and combinations thereof shows a

synergistic effect.

Accordingly, the present invention allows the manufacture of compositions with an improved residual enzyme activity, This results in a composition with a higher cleaning activity. It also makes it possible, should this be desired, to decrease the amount of enzyme (s) in the composition while retaining activity, which results in a more cost-effective composition. It may also be possible to reduce the content of surfactant, builders, or other components of the cleaning composition. Further, it allows the use of surfactants which are known to affect enzyme stability, thus broadening the possibilities for formulating liquid detergent compositions.

Within the context of the present specification the wording storage stability refers to the retention of activity of the enzyme (s) in the composition upon storage, as can be seen from the residual enzyme activity after storage, In one embodiment of the present invention an enzyme-containing liquid detergent composition is provided wherein the enzyme activity after storage at 37°C for 2 months is at least 40% of the enzyme activity of the freshly prepared composition, in particular, at least 50%, more in particular at least 60%.

The divalent lactate salt is selected from calcium lactate, magnesium lactate, zinc, lactate, and combinations thereof. The use of calcium lactate is presently considered preferred, whether or not in corabination with magnesium lactate and/or zinc lactate. Therefore, in erne embedimerit,, it may be preferred for the divalent lactate salt to consists for at least 50 wt . % of calcium lactate, in particular for at least 70 wt . %, ^"more in particular for at least 90%, still more in particular for at least 95%, In one embodiment, only calcium lactate is used as divalent lactate salt.

The monovalent lactate salt selected from sodium lactate, potassium lactate, ammonium lactate, and combinations thereof .

The use of sodium lactate is presently considered preferred, whether or not in combination -with potassium, lactate and/or ammonium lactate. Therefore, in one embodiment, it may be preferred for the monovalent lactate salt to consists for at least 50 wt , % of sodium lactate, in particular for at least 70 wt . % , more in particular for at least 90%, still more in particular for at least 95%. In one embodiment, only sodium lactate is used as divalent lactate salt .

The total of monovalent and divalent lactate salt as

described above generally is between 0,1 and 1.0 wt . % . When the total amount of these compounds is below 0.1 wt . % , the advantageous effect of the present invention will be obtained to a too limited extent. Preferably, a total amount of at least 1 wt . % is used. In some embodiments an amount of at least 2 wt . % may be used. A value of at most 7 wt . % may be mentioned as preferred value.

The divalent lactate salt is generally present in an amount of 0.05-5 wt . %, calculated on the total of the enzyme- containing liquid detergent composition. If the amount of divalent lactate salt is below 0.05 wt . % , the effect of the present invention will not be obtained; if it is above 5 wt . % , no additional stabilising effect will be obtained.

Preferably, the amount of divalent lactate salt is at least 0.1 wt.%, more in particular at least 0.5 wt . % . As a preferred maximum, a value of 4 wt.% may be mentioned, more in particular 3 wt.%.

The monovalent lactate salt is generally present in an amount of 0.05-5 wt . %, calculated on the total of the enzyme- containing liquid detergent composition. If the amount of monovalent lactate salt is below 0.05 wt . % , the effect of the present invention will not be obtained; if it is above 5 wt.%, no additional stabilising effect will be obtained.

Preferably, the amount of monovalent, lactate salt is at least 0.1 wt.%, more in particular at least 0.5 wt . % . As a

preferred maximum, a value of 4 wt . % may be mentioned, more in particu1ar 3 wt . % , The weight ratio between the monovalent and divalent lactate salt is generally between 0.1:1 and 10:1. For values outside this range the synergistic effect of the present invention is unlikely to be obtained. In one embodiment, a preferred ratio is between 0.2:1 and 5:1. A more preferred range is between 0.5:1 and 2:1.

The enzyme-containing liquid detergent composition according to the invention contains at least one enzyme . Suitable enzymes for use in detergent compositions are known in the art, and commercially available. Examples include proteases, amylases, lipases, cellulases, pectinases, and

hemicellulases . In one embodiment, the composition comprises at least an amylase. In another embodiment, the composition comprises at least a protease. In a further embodiment, the composition comprises an amylase and a protease. The enzyme or enzymes are present in amounts conventionally used, in the art, e.g., in an amount of 0.0001 to 2 wt.%, calculated on the final composition. The enzyme-containing liquid detergent composition according to the invention comprises at least one surfactant . Suitable surfactants are known in the art and include nonionic

surfactants , cationic surfactants, anionic surfactants, and zwitterionic surfactants .

The amount of surfactant in the composition generally is in the range of 1-60 wt . % , calculated on the total weight of the composition .

When included therein the detergent will usually contain from about 1% to about 40% of an anionic surfactant such as linear alkylbenzeunfeslonate, alpha-olefinsulfonate, a.1 ky1 sulfate (fatty alcohol sulfate) , alcohol ethoxysulfate , secondary aIkanesulfonate, alpha- suito fatty acid methyl ester, aikyl- or a.l kenyIsuccinic acid or soap.

When included therein the detergent will usually contain from about 0.2% to about 40% of a non-ionic surfactant such as alcohol ethoxylate, nonylphenol ethoxylate, alkylpoly- glycoside, alkyldimethylamineoxide, ethoxylated fatty acid monoethanolamide, fatty acid raonoethanolamide, polyhydroxy alkyl fatty acid amide, or N-acyl N-alkyl derivatives of glucosamine ( "giucamides " ) .

Additionally cationic and zwitterionic surfactants may be included such as betaines, quaternary ammonium salts and quaternary aikoxy ammonium salts.

The detergent composition may additionally comprise one or

.more additional components known in the art for enzyme- containing liquid detergent compositions.

For example, the detergent composition may contain 0-65 % of a detergent, builder or complexing agent such as zeolite, diphosphate, triphosphate, phosphonate, carbonate, citrate, nitrilotriacetic acid, et.hvienedi aminetetraacetic acid, diethylenetrrarcinepentaacetic acid, alkyl- or alkenylsuccinic acid, soluble silicates or layered silicates, If so desired, the detergent composition may comprise one or more polymers . Examples are carboxymethyl-cellulose,

poly (vinylpyrrolidone) , poly (ethylene glycol) , polyvinyl alcohol) , poly (vinylpyridine- N-oxide) , poly { vinylimidazole) , polycarboxylates such as polyacrylates , maleic/acrylic acid copolymers and lauryl methacrylate/acrylic acid copolymers . If so desired, the detergent composition may contain a bleaching system which may comprise a H202 source such as perborate or percarbonate which may be combined with a peracid-forming bleach activator such as

tetraacetylethylenediamine or nonanoyloxybenzenesu.1 £onate .

Alternatively, the bleaching system may comprise peroxyacids of e.g. the amide , imide, or su.Ifone type.

1 so desired, the composition may comprise a thickening agent and/or rheoiogy modifyer such as cocomethylethylamide, cocodiiaethylethylainide, and acrylate copolymers, e.g., in an amount of 0,1- 3 wt . % . If so desired, the composition may also comprise a pH regulating agent, e.g., in an amount of 0.1-3 wt.%. The composition may also comprise one or more compounds selected, from the group of preservatives and antibacterial agents, e.g., in an amount of 0.1-3 wt . %, fragrance compounds, e.g. , in an amount, of 0.1-1 wt.%, and colouring or pearlescent agents, e.g., in an amount of 0.1-1 wt.%. These compounds are known in the art and require no £urther e1uci d.ation here .

While not required, in one embodiment the composition may contain additional enzyme stabilisers known in the art. As conventional stabilisers may be mentioned po.lyols such as propylene glycol, di ethylene glycol, methyl propane diol, or glycerol, sugars or sugar alcohols, boric acid or boric acid derivatives such as 4-form.y.1phenyl boronic acid or mono- or triethanolamine . However, in the composition of the present invention, the lactate salts will contribute substantially to the stabilisation of the enzyme, making it possible to use less - or no - conventional enzyme stabilising components. In one embodiment, the present invention allows the formulation of a liquid detergent composition which contains only low amounts of borates, or which is substantially free of borates .

In one embodiment, the liquid detergent composition according to the invention contains less than 2 wt . % borate {calculated as boric acid) , in particular less than 1 wt . % , still more in particular less than 0.5 wt.%. In one embodiment the

composition is substantially free from borate, which means that borate is only present in such amounts as cannot

reasonably be avoided.

In another embodiment , the liquid detergent composition according to the invention contains less than 2 wt . %

propylene glycol, in particular less than 1 wt . %, still more in particular less than 0.5 wt . % . In one embodiment the composition is substantially free from propylene glycol.

In one embodiment, substantially no additional enzyme

stabilising components are present in the composition

according to the invention.

The composition generally has a pH in the range of 5-12, more in particular in the range of 6-11, still more in particular in the range of 7-1.0. In one embodiment the composition has a pH in the. range of 6-8.

The present invention also pertains to a process for

manufacturing the enzy.me~conta.ini.ng liquid detergent

composition described above, which comprises the steps of combining and homogenising the surfactant, the enzyme or enzymes, the monovalent lactate salt, the divalent lactate salt, and water. The components may be provided in any form, depending on their nature, e.g. , in the form of solid

composition, dispersions or solutions in water or other solvents, pastes, or in any other form. The divalent lactate salt arid the monovalent lactate salt can be added in the form of the stipulated salts, but they can also be added in the form of compounds which, with other compounds present in the detergent composition, result in the presence of a divalent lactate salt and a raonovaient lactate salt in accordance with the invention. For example, in one embodiment, a combination of a divalent lactate salt and lactic acid is provided to the composition, wherein the lactic acid results in the presence of sodium lactate, due to the presence of, e.g. , a sodium salt of a surfactant.

The monovalent and divalent lactate salts may be combined with the other ingredients in separate steps. They may also be combined with the other ingredients in a single step. In one embodiment in a first step a mixture is prepared which comprises a combination of the monovalent and divalent lactate salts, and in a second step the mixture is combined with the other components . This mixture may, for example, be in the form of an aqueous solution, e.g., a solution with a concentration of at least 10 wt. ,%. The upper limit of the concentration will be determined by solubility

considerations ,

In. another embodiment, a mixture is prepared of a divalent lactate salt and lactic acid, as described above. This mixture may, for example, be present in the form of an aqueous solution, with the concentration considerations given above .

In another embodiment, the mixture is in the form of a solid composition .

The present invention also pertains to a process for

increasing the stability of a enzyme-containing liquid detergent composition by incorporating therein a monovalent lactate salt and a divalent lactate salt, as specified above. The present invention also pertains to the use of a monovalent lactate salt and a divalent lactate salt as specified above for increasing the stability of a enzyme- containing liquid detergent composition.

For preferred embodiments, reference is made to what has been stated above for the composition .

The present invention will be elucidated by the following examples, without being limited thereto or thereby.

Example 1: Comparison of composition according to the invention with comparative composite oris

A base for a liquid detergent composition was prepared having the following composition :

The base formulation was used to prepare liquid detergent compositions as follows:

To the base composition, stabiliser compounds were added, viz, sodium lactate, calcium lactate, or combinations

thereof, or conventional stabilisers , The composition was adjusted to pH 9 with, aqueous NaOH (50%) or H₂S0₄, Then, the enzymes were added, viz. Termamyl, a thermostable alpha- amylase, and Alcalase a protease. The final compositions as follows:

The amount of stabiiisers in the compositions of the Example- arid the Comparative Examples are given in Table 2 below. For calcium (di ) lactate 1 wt.% was used, for sodium lactate 2 wt .%.

The stability of the enzyine-containing liquid detergent composition was determined after storage at a temperature of 37 °C for various periods . The residual protease activity and alpha-amylase activity were determined, and the results are presented in the following tables, with the activity of the Example according to the invention just after preparation being set at 100%. The A_50% is the half-life value of the residual enzyme activity in days. Table 3: Residual aloha -amylase activity (%) durina storage at 37

nd stands for not determined

ad stands for not determined

From Tables 3 and 4 it can be seen that the use of the combination of sodium lactate and calcium lactate results in an increased half life of both aipha-ainylase and protease enzyme as compared to the use of either sodium lactate alone or calcium lactate alone. The effect is especially pronounces for protease, where the composition according to the

invention shows an A_50% of 12.5 days, while all comparative systems show an A₅₀% of 11 days or lower.

Example 2 : Effect of amounts of the two components

Compositions were prepared analogous to those in Example 1, but using different, amounts of sodium lactate and calcium lactate. The compositions are given in the following table: Table b: Composition NaL+CaL2 (2:1) at different

The stability of the enzyme-containing liquid detergent composition was determined after storage at a temperature of 37 °C for various periods. The residual protease activity and alpha-amylase activity were determined, and the results are presented in the following tables, with the activity of Ex 2 . 1 just, after preparation being; set at 100 % .

Table 7; Residual protease activity (%) during storage 37 °C

From tables 6 and 7 it can be seen that, in this composition the residual alpha-amylase activity is highest at. a total concentration around 1 wt . % . The residual protease activity is highest at a total concentration of 5 wt. %, and may even increase at higher concentrations. This shows that the total amount of stabiliser should be selected as a balance for residual protease activity and residual amylase activity. Example 3; Effect of ratio between the two components

Composit ions were prepared analogous to those in Example 1, taut using different amounts of sodium lactate and calcium lactate, to give a total wt . % of lactates of 3 wt . % , but with different ratios between the components. The compositions are given in the following table:

The stability of the enzyme-containing liquid detergent composition was determined after storage at a temperature of 37 °C for various periods. The retention of the protease activity and alpha-amylase activity were determined, and the results are presented in the following tables, with the activity of Ex 3.3 just after preparation, being set at 100%.

From Tables 9 and 10 it can be seen that in the tested composition the amylase residual activity is highest at a NaL:CaL2 weight ratio of about 0.33:1, while the protease residual activity is highest at a NaL : CaL2 weight ratio of about 1:1 to 2:1.

Example 4: Comparison with commercial stabilisers To show the effect of the composition according to the invention as compared to commercial borate stabilisers, compositions were prepared analogous to those in Example 1, but using different types and amounts of stabilisers. The borate was added to the composition in the form of boric acid.

The stability of the enzyme-containing liquid detergent compositions were was determined after storage at a

temperature of 37 °C for various periods. The residual

protease activity and alpha-amylase activity were determined, and the results are presented in the following tables, with the activity of Ex 4.1 just after preparation being set at 100% ,

As can be seen, from the tables above _r the combination of sodium lactate and calcium lactate shows a residual activity .for protease which is substantially improved as compared to that obtained when using borate. For alpha-amylase the effect of the residual activity depends on the concentration.

Claims

1. Enzyme-containing liquid detergent composition which comprises water, a surfactant, at least one enzyme, a divalent lactate salt selected, from calcium lactate,

magnesium lactate, zinc lactate, and combinations thereof, and a monovalent lactate salt selected from sodium lactate, potassium lactate, ammonium lactate, and combinations thereof .

2. Enzyme-containing liquid detergent composition according to claim 1 wherein the divalent lactate salt comprises calcium lactate and the monovalent lactate salt comprises sodium lactate .

3. Enzyme-containing liquid detergent composition according to claim 1 or 2, wherein the total of monovalent and divalent lactate salt is between 0.1 and 10 wt . % .

4. Enzyme-containing liquid detergent composition according to any one of the preceding claims which contains amylase, protease, or a combination thereof.

5. Enzyme-containing liquid detergent composition according to any one of the preceding claims wherein the weight ratio between the monovalent and divalent lactate salt is between 0.1:1 and 10: 1, in particular between 0.2:1 and 5:1, more in particular between 0.5:1 and 2:1.

6. Process for improving the storage stability of an enzyme-containing liquid detergent composition which

comprises incorporating therein a divalent lactate salt selected from calcium lactate, magnesium lactate, zinc lactate, and combinations thereof, and a monovalent lactate salt selected from sodium lactate, potassium lactate, ammonium lactate,, and combinations thereof.

7, Use of a combination of a divalent lactate salt selected from calcium lactate, magnesium lactate, zinc lactate, and combinations thereof, and a monovalent lactate salt selected from sodium lactate, potassium lactate, ammonium lactate, and combinations thereof to improve the storage stability of an enzyme-containing liquid detergent compos.itio.ru

8. Combination of a divalent lactate salt selected from calcium, lactate, magnesium lactate, zinc lactate, and

combinations thereof, and a monovalent lactate salt selected from sodium lactate, potassium lactate, ansrtonium lactate, and combinations thereof for use in improving the storage

stability of an enzyme-containing liquid detergent

composition.