Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/16—Organic compounds
  • C11D3/38—Products with no well-defined composition, e.g. natural products
  • C11D3/386—Preparations containing enzymes, e.g. protease or amylase
  • C11D3/38663—Stabilised liquid enzyme compositions

Definitions

• the present invention relates to stabilized aqueous enzyme compositions which preferably contain detergent compounds.
• Description of the Art - The formulation of enzyme-containing aqueous liquid detergent compositions is very difficult due to the rapid decrease in enzymatic activity in aqueous media during storage.
• the stabilized aqueous enzyme compositions of this invention comprise: (a) from 0% to about 75% of a detergent surfactant; (b) from about 0.025% to about 1% of an enzyme, preferably a proteolytic enzyme; (c) from 0% to about 20%, preferably from about 5% to about 15% of a low molecular weight primary or secondary alcohol; (d) from about 0.1% to about 10%, preferably from about 0.3% to about 3% for lower pH products and from about 3% to about 10% for higher pH products, of a short chain length carboxylic acid salt, preferably a formate; (e) a soluble calcium salt to give from about 0.1 to about 10, preferably from about 0.5 to about 1.5 for lower pH products and from about 4 to about 8 for higher pH products, millimoles of calcium ion per liter; and (f) the balance water, the pH of the product being from about 6.5 to about 10, preferably from about 7 to about 8.5 for enzyme stability and from about 8.5 to about 10 for detergency.
• an enzyme
• the detergent surfactant can be selected from nonionic, anionic, cationic, zwitterionic, amphoteric and semi-polar nonionic surfactants and mixtures thereof.
• the surfactant comprises a substantial portion of nonionic surfactant together with either an anionic surfactant, a semi-polar nonionic surfactant, or cationic surfactant or mixtures thereof.
• the surfactants are preferably from about 10% to about 75%, more preferably from about. 20% to about 50% of the formula.
• nonionic surfactants are conventionally produced by condensing ethylene oxide with a hydrocarbon having a reactive hydrogen atom, e.g., a hydroxyl, carboxyl, amino, or amido group, in the presence of an acidic or basic catalyst.
• Nonionic surfactants have the general formula RA(CH 2 CH 2 O) n H wherein R represents the hydrophobic moiety, A represents the group carrying the reactive hydrogen atom and n represents the average number of ethylene oxide moieties.
• R typically contains from about 8 to about 22 carbon atoms, but can also be formed by the condensation of propylene oxide with a lower molecular weight compound, n usually varies from about 2 to about 24.
• the hydrophobic moiety of the nonionic compound is preferably a primary or secondary, straight or slightly branched, aliphatic alcohol having from about 8 to about 24, preferably from about 12 to about 20 carbon atoms.
• suitable nonionic surfactants can be found in U.S. Patent 4,111,855 disclosed hereinbefore and incorporated herein by reference.
• Synthetic anionic surfactants can be represented by the general formula R 1 SO 3 M wherein R 1 represents a hydrocarbon group selected from the group consisting of straight or branched alkyl radicals containing from about 8 to about 24 carbon atoms and alkyl phenyl radicals containing from about. 9 to about 15 carbon atoms in the alkyl group.
• M is a salt forming cation which typically is selected from the group consisting of sodium, potassium, ammonium, monoalkanol- ammonium, dialkanolammonium, trialkanolammonium, and magnesium cations and mixtures thereof.
• a preferred synthetic anionic surfactant is a water-soluble salt of an alkylbenzene sulfonic acid containing from about 9 to about 15 carbon atoms in the alkyl group.
• Another prererrect synthetic anionic surfactant is a water-soluble salt of an alkyl polyethoxylate ether sulfate wherein the alkyl group contains from about 8 to about 24, preferably from about 10 to about 18 carbon atoms and there are from about 1 to about 20, preferably from about 1 to about 12 ethoxy groups.
• Other suitable anionic surfactants are disclosed in U.S. Patent 4,170,565, Flesher et al, issued October 9, 1979, incorporated herein by reference.
• Suitable anionic surfactants can include soaps and fatty acids containing from about 8 to about 24 carbon atoms, but it should be recognized that such soaps and fatty acids do tend to tie up calcium ions and thus are preferably limited to from about 1% to about 25%, most preferably from about 10% to about 20%.
• Suitable cationic surfactants have the general formula Y L Z wherein each R2 is an organic group containing a straight or branched alkyl or alkenyl group optionally substituted with up to three phenyl or hydroxy groups and optionally interrupted by up to four structures selected from the group consisting of and mixtures thereof, each R 2 containing from about 8 to 22 carbon atoms, and which may additionally contain up about 12 ethylene oxide groups, m is a number from 1 to each R 3 is an alkyl or hydroxyalkyl group containing fre to 4 carbon atoms or a benzyl group with no more than or in a molecule being benzyl, x is a number from 0 to 11, remainder of any carbon atom positions being filled by hydrogens, Y is selected from the group consisting of: therein p is from 1 to 12, wherein p is from 1 to 12, and (9) mixtures thereof.
• Zwitterionic surfactants include derivatives of aliphatic quaternary ammonium, phosphonium, and sulphonium compounds in which the aliphatic moiety can be straight or branched chain and wherein one of the aliphatic substituents contains from about 8 to 24 carbon atoms and one contains an anionic water-solubilizing group.
• Particularly preferred zwitterionic materials are the ethoxylated ammonium sultanates and sulfates disclosed in U.S. Patents 3,925,262, Laughlin et al, issued December 9, 1975 and 3,929,678, Laughlin et al, issued December 30, 1975, said patents being incorporated herein by reference.
• Ampholytic surfactants include derivatives of aliphatic heterocylic secondary and ternary amines in which the aliphatic moiety can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 24 carbon atoms and at least one aliphatic substituent contains an anionic water-solublizing group.
• Semi-polar nonionic surfactants include water-soluble amine oxides containing 1 alkyl or hydroxy alkyl moiety of from about 8 to about 28 carbon atoms and 2 moieties selected from the group consisting of alkyl groups and hydroxy alkyl groups, containing from 1 to about 3 carbon atoms which can optionally be joined into ring structures; water-soluble.
• phosphine oxides containing 1 alkyl or hydroxy alkyl moiety of from about 8 to about 28 and 2 moieties selected from the group consisting of alkyl groups and hydroxy alkyl groups, containing from about 1 to about 3 carbon atoms; and water-soluble sulfoxides containing 1 alkyl or hydroxy alkyl moiety of from about 8 to about 28 carbon atoms and a moiety selected from the group consisting of alkyl and hydroxy alkyl moieties of from 1 to 3 carbon atoms.
• the enzyme component herein is incorporated in an amount of from about 0.025 to about 1%, preferably from about 0.05% to about 0.2%.
• the preferred proteolytic enzyme component should give to the composition a proteolytic activity of at least about 4 Anson units per liter, preferably from about 15 to about 70 Anson units per liter, most preferably from about 20 to about 40 Anson units per liter.
• a proteolytic activity of from about 3 to about 5 Anson units per gram of product is desirable.
• Other enzymes, including amylolytic enzymes can also be included.
• the enzyme component is characterized by an isoelectric point of from about 8.5 to about 10, preferably from about 9 to about 9.5
• suitable proteolytic enzymes include many species which are known to be adapted for use in detergent compositions and, in fact, have been used in detergent compositions.
• Sources of the enzymes include commercial enzyme preparations such as "Alcalase” sold by Novo Industries, and “Maxatase” sold by Gist-Brocades, Delft, The Netherlands, which contain from about 10% to about 20% enzyme.
• Other preferred enzyme compositions include those commercially available under the tradenames SP-72 (“Esper- ase”) manufactured and sold by Novo Industries, A/S, Copenhagen, Denmark and "AZ-Protease” manufactured and sold by Gist-Brocades, Delft, The Netherlands.
• the low molecular weight primary or secondary alcohol is exemplified by methanol, ethanol, propanol, and isopropanol.
• Monohydric alcohols are preferred for solubilizing the surfactant but polyols containing from 2 to about 6 carbon atoms and from 2 to about 6 hydroxy groups can be used and can provide improved enzyme stability.
• polyols include propylene glycol, ethylene glycol and glycerine.
• Ethanol is a particular preferred alcohol.
• the composition contains from 0% to about 20%, preferably from about 5% to about 15%, most preferably from about 9% to about 11.4% of the alcohol.
• the short chain carboxylic acid salt is preferably water-soluble and more preferably is a formate, e.g., sodium formate.
• the formates are surprisingly much more effective than other short chain carboxylic salts like the acetates and the propionates.
• the short chain carboxylic acid salt is used at a level from about 0.1% to about 10%, preferably from about 0.3% to about 3%, more preferably from about 0.5% to about 1.5% when the product pH is below about 8.5 and from about 3% to about 10%, preferably from about 4% to about 8%, when the product pH is from about 8.5 to about 10. At the higher pH's (8.5-10) only formates are suitable.
• Any water-soluble calcium salt can be used as a source of calcium ions, including calcium acetate, calcium formate and calcium propionate.
• the level of calcium ions in the composition is from about 0.1 to about 10 millimoles of calcium ion per liter, preferably from about 0.5 to about 1.5 millimoles of calcium ion per liter when the product pH is below about 8.5 and from about 4 to about 8 millimoles when the product pH is from about 8.5 to about 10.
• soap or fatty acid is present, the preferred level is from about 2 to about 6 millimoles of calcium ion per liter.
• Zinc and magnesium ions can replace the calcium ion completely or in part.
• the pH of the product is from about 6.5 to about 10, preferably from about 7 to about 8.5 to obtain a combination of enzyme stability and detergency.
• a pH of from about 8.5 to about 10 preferably 9 to 10 is best for detergency. Both high and low pH's adversely affect enzyme stability and low pH's give up too much detergent effectiveness.
• Suitable pH buffers include mono-, di- and tri-ethanolamines. When the product pH is from 8.5 to about 10 triethanolamine is the best buffer. When soap or fatty acid is present, the preferred pH is from about 7 to about 7.5.
• the balance of the composition is usually water, but the composition can contain other ingredients, including perfumes, dyes, opacifiers, optical brighteners, suds suppressors, pH adjusting agents, etc. Disclosures of suitable ingredients can be found in the patents and patent applications incorporated herein by reference.
• the product is essentially free of materials such as detergent builders that tie up calcium ions to permit sufficient free calcium ions to be present although with the formate, excellent stability is achieved with very low levels of calcium ions, especially in the low pH range.
• Preferred Compositions Containing Soap low pH range only).
• homogeneous aqueous detergent compositions of this invention comprise: (a) from about 20% to about 50% by weight of an organic synthetic surface-active: agent; (b) from about 3% to about 15% by weight of a saturated fatty acid having 1.0 to 16 carbon atoms in the alkyl chain; (c) from 0.025% to about 1% by weight of an enzyme; (d) from 0.1% to about 3% by weight of a carboxylic acid having from 1 to 3 carbon atoms; and (e) less than 2 millimoles of enzyme-accessible calcium per kilo of the detergent composition, the pH of the composition measured as is at 20°C, being from about 6.5 to 8.5.
• the saturated fatty acids preferably have from 12 to 14 carbon atoms in the alkyl chain
• the detergent enzymes are represented by proteases or mixtures of proteases and amylases
• the short chain carboxylic acid is represented by formic acid
• the enzyme-accessible calcium is present in an amount of from about 0.5 to 1.5 millimoles per kilo of the detergent composition
• the pH of the composition, as is, is in the range from about 7 to about 7.5.
• These preferred compositions of this invention are substantially builder free. While the fatty acids and/or soaps are not considered as detergent builders/sequestrants in the context of this invention, the claimed compositions do not contain more than minor amounts of sequestrants.
• the saturated fatty acid component is incorporated in an amount of from about 3% to about 15%, preferably from about 5% to about 11%.
• the saturated fatty acids have from 10 to 16, preferably 12 or 14 carbon atoms in the alkyl chain.
• the most preferred fatty acids are either lauric acid or lauric and myristic fatty acid in a mixture of 5:1 to 1:1.
• the compositions herein can comprise certain amounts of unsaturated fatty acids having, for example, 16 or 18 carbon atoms in the alkyl chain.
• unsaturated fatty acids are oleic fatty acid and palmitoleic fatty acid.
• the enzyme component is incorporated in an amount of from about 0.025 to about 1%, preferably from about 0.5% to about 0.2%.
• the preferred proteolytic enzyme component should give to the composition a proteolytic activity of at least about' 4 A nson units, preferably from about 8 to about 30 Anson units, most preferably from about 10 to about 20 Anson units per kilo of the liquid detergent composition.
• the enzyme component can be represented by a mixture of proteases and amylases. The proteolytic activity of that mixture is as defined hereinbefore.
• the enzyme component is characterized by an isoelectric point of from about 8.0 to about 10, preferably from about 8.5 to about 9.5.
• the Carboxylic Acid is characterized by an isoelectric point of from about 8.0 to about 10, preferably from about 8.5 to about 9.5.
• this ingredient is used in an amount from 0.1% to about 3%, preferably from 0.5% to 15% by weight.
• Preferred are the water-soluble salts. Most preferred is formic acid or the formates such as sodium, potassium, lithium, amines and substituted amines, inclusive of mono-, di-, and tri-ethanolamines.
• the Enzyme-Accessible Calcium The Enzyme-Accessible Calcium.
• compositions herein comprise less than about 2, preferably from 0.5 to 1.5, millimoles of enzyme-accessible calcium per kilo of the homogenous enzyme contain- ing detergent product.
• the claimed compositions are-substantially free of seguestrants, for example, polyacids capable of forming calcium complexes which are soluble in the composition. However, minor amounts of sequestrants such as polyacids or mixtures of polyacids can be used.
• The- enzyme-accessible calcium is defined as the amount of calcium- ions effectively available to the enzyme component.
• the calcium sequestration resulting from e.g., 0.5% of a mixture of polyphosphonates and polyacids as exemplified hereinafter can represent about 1 to about 1.5 millimoles of calcium per kilo of product.
• the total calcium incorporated into the compositions is thus comprised of the enzyme-accessible calcium and also .the calcium sequestered by the low levels of polyacids. From a practical standpoint the enzyme-accessible calcium is therefore the soluble calcium in the composition in the absence of any strong sequestrants, e.g., having an equilibrium constant of complexation with calcium equal to or greater than 1.5 at 20°C
• the pH of these preferred products is from about 6.5 to about 8.5, preferably from about 7 to about 7.5 to obtain a combination of enzyme stability and detergency. Both high and low pH's can adversely affect enzyme stability.
• compositions herein frectoently contain a series of optional ingredients which are used for the known functionality in conventional levels.
• inventive compositions are premised on aqueous enzyme-containing, detergent compositions containing a critical ternary system as fully explained above, it is frequently desirable to use a phase regulant. This component together with water constitutes then the solvent matrix for the claimed liquid compositions. Suitable phase regulants are well-known in liquid detergent..
• phase regulants are: ethanol; n-propanol; isopropanl; butanol; 1,2-propanediol; 1,3-propanediol; n-hexanol; monomethyl-, -ethyl-, -propyl, and mono-butyl ethers and di-ethylene glycol.
• Additional phase regulants having a relatively high boiling point and low vapor pressure can also be used provided they. do not react with. the other ingredients of the compositions.
• phase regulants are a further class of phase regulants. suitable for use herein.
• these hydrotropes include salts of alkylarylsulfonates having up to 3 carbon atoms in the alkylgroup, e.g., sadium, potassium, ammonium and ethanolamine salts of xylene-, toluene-, ethylbenzene- cumene-,and isopropylbehzene sulfonic acids.
• the phase regulant is frequently us.ed in an amount from about 5% to. about 20%; the sum of phase regulant and water is normally in the range. from 65% to 35%
• compositions herein can contain a series of further optional ingredients which are mostly used in additive levels usually below about 5%
• additives include; polyacids, suds regulants, opacifiers, antioxidants, bactericides, dyes, perfumes, brightener 3 and the like.
• a preferred additive is represented by a polyacid or mixture, of polyacids in an amount below about 1%.
• Suitable polyacids. can include: citric, cyclohexane-1,1-dicarboxylic, cyclooprooopane-1-1dicarboxylic, dimethylmalic, glutaric, o-hydroxyb'enzoic, m-hydroxybenzoic, p-hydroxybenxoic, itaconic, methylsuccinic, sodium tripolyphosphates, and nitrilotriacctic acic- Preferred polyacid species for use herein can be represented by citric acid and organo-phosphonic acids and mixtures thereof.
• alkylene-polyamino- polyalkylene phosphonic acids are ethylene diamine tetrame- thylenephosphonic acid, hexamethylene diaminetetramethylene- phosphonic acid, diethylene triaminepentamethylenenephosphonic acid, and amino-trimethylenephosphonic acid or the salts thereof.
• organophosphonic acids/salts are preferably used in an. amount from 0.1%-0.8%
• the beneficial utilization of the claimed compositions under yarious usage conditions can. require the utilization of a suds regulant. While generally all detergent suds regulants can be utilized preferred for use herein are alkylated polysiloxanes such as dimethylpolysiloxane also frequently termed silicones, The silicon.es are frequently usLed in a leyel not. exceesing 0.5% most preferably between 0.01% and 0.2%
• opacifiers can also be desirable to utilize opacifiers inasmuch as they contribute to create a uniform appearance of the concentrated liquid detergent compositions.
• suitable opacifiers include: polystyrene commercially known as LYTRON. 621 manufactured by MONSANTO CHEMICAL CORPORATION. The opacifiers are frequently used in an amount from 0,3% to 1,5%.
• compositions herein can also contain known antioxidants for their known utility, frequently radical scavengers, in the art established levels i.e. 0,001% to 0,25% (by reference to total composition). These antioxidants are frequently introduced in conjunction with the fatty acids. While many suitable antioxidants are readily known and available for that purpose especially preferred for use in the compositions herein are: 2,6 ditertiary butyl-p-cresol, more commonly known as butylated hydroxytoluene, BHT, and 2-tertiarybutyl-4-hydroxyanisole or 3-tertiarybutyl-4-hydroxy- anisole more commonly known as BHA or butylated hydroxyanisolc. Other suitable antioxidants are: 4,4'thiobis(6-tert-butyl-m-cresol) and 2-methyl-4,6-dinonyl phenol.
• 21 day stability data follows the same general trend. As can be seen from the above data, the formate is best, followed by the acetate, which is followed by the propionate. The total amount of Ca ++ present is about 15 millimoles/ liter. (Some is added with the enzyme slurry.)
• Liquid detergent compositions were prepared by mixing the individual ingredients listed hereinafter in the stated proportions.
• compositions I-IV contained 3 millimoles and compositions V-VII 5 millimoles of calcium/liter of the composition.
• compositions II, III, IV, VI and VII were markedly superior vs. comparable compositions I and V which did not contain the formate stabilizer.
• compositions III and VI wherein the sodium formate is replaced by a substantially equivalent molar level of a salt selected from: triethanolammonium formate, diethanolammonium formate; monoethanolammonium formate; potassium formate; lithium formate and ammonium formate.
• a salt selected from: triethanolammonium formate, diethanolammonium formate; monoethanolammonium formate; potassium formate; lithium formate and ammonium formate.
• Liquid detergent compositions were prepared by mixing the listed ingredients in the stated proportions.
• composition A is representative of the prior art
• Compositions B and C are reference compositions based on routine variations vs, the art compositions.
• Composition I is an. example of the invention herein.
• the level of calcium in compositions A and B represents, based on current art knowledge, the minimum needed to achieve acceptable enzyme stability.
• the amount of calcium in composition C was lowered to. the point where phase instability and precipitation-would not anymore occur.
• the testing data are summarized. below.
• composition I in accordance with this invention vs. formulationwise closely related art composition --A-- or what could be technical variations --B, C-- of known art formulations.
• compositions of this invention were prepared by mixing the listed components in the indicated proportions.
• Composition D is what could be a technical variation of the state of art whereas formulae IV and V are executions of the claimed invention.
• the residual enzymatic activity (expressed in % of initial activity) were measured following exposure to accelerated storage conditions (48 hours at 40°C).
• compositions of this invention are prepared bu mixing the listed ingredients in a conventional manner.
• compositions VI-XII are clear, homogeneous products having a markedly improved enzyme stability, especially upon storage.

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Cited By (12)

Citations (3)

• 1980
  • 1980-11-07 DE DE8080201059T patent/DE3068554D1/de not_active Expired
  • 1980-11-07 EP EP19800201059 patent/EP0028866B1/de not_active Expired

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