The invention relates to detergents characterized in that they contain xcex1-amylase from Bacillus amyloliquefaciens and protease from Bacillus lentus, optionally modified by genetic engineering, in addition to our usual ingredients compatible with said enzymes.

The present invention relates to enzyme containing detergents comprising besides customary constituents an amylase from Bacillus amyloliquefaciens and a certain protease.
Amylases have the function of facilitating the removal of starchy stains by means of catalytic hydrolysis of the starch polysaccharide, and have been used for this purpose for a fairly long time in dishwashing detergents, but also in detergents for use in textile laundering. In by far the great majority of cases the amylase involved has comprised a heat-stable amylase from Bacillus licheniformis, which is customary in commerce under the designation Termamyl(copyright), for example. More recently, there has been increased use in such compositions of genetically manipulated amylases; that is, amylases whose amino acid sequence has been altered, using gene technology methods, in comparison to naturally occurring amylases. As well as increasing their capacity to perform, the objective of genetically modifying amylases is essentially to enhance the stability of the enzyme, especially their stability to attack by oxidizing agents. One approach toward achieving this objective, which was proposed in International Patent Application WO 94/18314, consists in removing particularly oxidation-susceptible amino acids, such as methionine, tryptophan, cysteine or tyrosine, from the amino acid sequence of the amylase, or replacing them by other amino acids more stable to oxidation. A similar approach is proposed in International Patent Application WO 95/21247, which recommends replacing at least one methionine in the amylase amino acid sequence by an amino acid which is neither methionine nor cysteine.
Although such genetic modifications may lead to improved amylase stability under certain application conditions, they do not help to increase the contribution of the amylase to the wash or cleaning performance of corresponding compositions comprising the amylase.
Besides amylases, other enzymes, especially proteolytic enzymes, are being used to an increased extent in laundry detergents, laundering assistants, and cleaning products. Those used at present comprise almost exclusively proteases from the subtilisin family. This family comprises extracellular proteins having a molecular weight in the range from about 20,000 to 45,000. Subtilisins are relatively unspecific enzymes which in addition to the hydrolytic effect on peptide bonds also have esterolytic properties (M. Bahn and R. D. Schmidt, Biotec 1, 119, 1987). Many representatives of the subtilisins have been the subject of precise physical and chemical characterization. Their three-dimensional structure is often known in detail through X-ray structural analysis. This has provided the prerequisites for molecular modeling and so-called protein engineering in the form of site-directed mutagenesis (Kraut, Ann. Rev. Biochem. 46, 331-358, 1977). Genetic modifications of proteases have been described on numerous occasions; in June 1991, for instance, there were already 219 known protein variants of the subtilisin obtained by protein engineering (A. Recktenwald et al., J. Biotechnol. 28, 1-23, 1993). The majority of these variants have been produced in order to enhance the stability of the proteases.
A protease from the subtilisin family which is active and stable under strongly alkaline conditions may be produced as described in International Patent Application WO 91/02792 in Bacillus lentus (DSM 5483). This Bacillus lentus alkaline protease (BLAP) can be produced by fermenting Bacillus licheniformis transformed using an expression plasmid which carries the gene for BLAP under the control of the promoter from Bacillus licheniformis ATCC 53926. Both the composition and three-dimensional structure of BLAP are known (D. W. Godette et al., J. Mol. Biol. 228, 580-595, 1992). This protease is characterized by the 269 amino acid sequence described in the cited literature, a calculated molecular weight of 26,823 daltons, and a theoretical isoelectric point of 9.7. Variants, accessible by mutation, of this Bacillus lentus DSM 5483 protease are described in U.S. Pat. No. 5,340,735. They include protease enzymes which lead to particularly low substrate damage, or destruction of the fiber assemblies, when textiles comprising proteinogenic fibersxe2x80x94for example, sheetlike textile structures of natural silk or woolxe2x80x94are laundered, especially when they are laundered repeatedly, and do so with no loss in cleaning performance.
It has surprisingly now been found that the combination of an optionally genetically manipulated protease from Bacillus lentus as described above and a naturally occurring xcex1-amylase leads to unexpectedly synergistic performance improvements when used in detergents.
The invention accordingly provides an amylase and protease containing detergent which comprises, in addition to customary ingredients compatible with such enzymes, xcex1-amylase from Bacillus amyloliquefaciens and protease from Bacillus lentus, which protease may optionally have been genetically manipulated.
The invention further provides for the use of a combination of xcex1-amylase from Bacillus amyloliquefaciens and protease from Bacillus lentus, which protease may optionally have been genetically manipulated, for enhancing the cleaning performance of detergents, especially with respect to starchy stains, when used in detergent solutions, especially aqueous detergent solutions. xcex1-Amylase from Bacillus amyloliquefaciens has been known for a long time, for example, from the U.S. Pat. No. 1,227,374. It is available commercially, for example, under the designation Amylase BAN(copyright).
A composition of the invention contains preferably from 0.001 mg to 0.5 mg, in. particular from 0.02 mg to 0.3 mg, of amylolytic protein per gram of the overall composition. The protein concentration may be determined using known methods, such as the bicinchonic acid technique (BCA technique, Pierce Chemical Co., Rockford, Ill.) or the Biuret technique (A. G. Gornall, C. S. Bardawill and M. M. David, J. Biol. Chem. 177, 751-766, 1948).
The composition preferably has a proteolytic activity in the range from about 100 PU/g to about 10,000 PU/g, in particular from 300 PU/g to 8000 PU/g. The protease activity is determined in accordance with the standardized method described below, as described in Tenside 7 (1970), 125: a solution of 12 g/l casein and 30 mM sodium tripolyphosphate in water of hardness 15xc2x0 dH [German hardness] (containing 0.058% by weight CaCl2.2H2O, 0.028% by weight MgCl2.6H2O and 0.042% by weight NaHCO3) is heated to 70xc2x0 C. and the pH is adjusted to 8.5 at 50xc2x0 C. by adding 0.1 N NaOH. 200 ml of a solution of the test enzyme in 2 percent strength by weight sodium tripolyphosphate buffer solution (pH 8.5) are added to 600 ml of the substrate solution. The reaction mixture is incubated at 50xc2x0 C. for 15 minutes. The reaction is then stopped by adding 500 ml TCA solution (0.44 M trichloroacetic acid and 0.22 M sodium acetate in 3 percent strength by volume acetic acid) and cooling (ice bath at 0xc2x0 C., 15 minutes). The TCA-insoluble protein is removed by centrifugation and 900 ml of the supernatant are diluted with 300 ml of 2 N NaOH. The absorbance of this solution at 290 nm is determined using an absorption spectrometer, the blank absorbance value being determined by measuring a centrifuged solution prepared by mixing 600 ml of the abovementioned TCA solution with 600 ml of the abovementioned substrate solution and then adding the enzyme solution. The proteolytic activity of a protease solution which under the stated measurement conditions brings about an absorbance of 0.500 OD is defined as 10 PU (protease units) per ml.
The proteases which can be used in accordance with the invention include not only the naturally occurring protease from Bacillus lentus but also genetically modified proteases of the abovementioned BLAP type in which in position 211 (BLAP numeration) the amino acid leucine (L in the common one-letter code) present at this position in the wild type protease has been replaced by aspartic acid (D) or glutamic acid (E) (L211D and L211E, respectively). These may be prepared as described in International Patent Application WO 95/23221. Instead of this or in addition to this it is possible for further modifications to have been made relative to the original Bacillus lentus protease, such as, for example, at least one of the amino acid replacements S3T, V4I, R99G, R99A, R99S, A188P, V193M and/or V199I. Particular preference is given to the use of a variant in which the amino acid replacements S3T+V4I+V193M+V199I+L211D have been performed. In the context of the above-described protease nomenclature relating to the replacement of individual amino acids, it should be noted that the numbering of the amino acid positions in BLAP differs from the frequently encountered numbering of subtilisin BPNxe2x80x2. The numbering of positions 1 to 35 is identical in subtilisin BPNxe2x80x2 and BLAP; owing to a lack of corresponding amino acids, the positions 36 to 54 in BLAP correspond to positions 37 to 55 in BPNxe2x80x2; positions 55 to 160 in BLAP correspond to positions 57 to 162 in BPNxe2x80x2; and positions 161 to 269 correspond to 167 to 275 in BPNxe2x80x2.
Especially for use in particulate compositions, as described for other enzymes, for example, in European Patent EP 0 564 476 or in International Patent Application WO 94/23005, the enzymes may have been adsorbed on carrier substances and/or embedded in coating substances in order to protect them against premature inactivation. In compositions of the invention, the combination of amylase and genetically modified protease, which is essential to the invention, may be used by incorporating the two separate enzymes, or conventionally separately compounded enzymes, or by protease and amylase compounded together in granules, as known, for example, from International Patent Applications WO 96/00772 or WO 96/00773.
In addition to the enzyme combination used in accordance with the invention, the detergents of the invention, which may be present as solids, especially pulverulent solids, in postcompacted particle form, as homogeneous solutions or suspensions may in principle comprise all known ingredients which are customary in such compositions. The compositions of the invention may in particular comprise builder substances, surface-active surfactants, bleaches based on organic and/or inorganic peroxygen compounds, bleach activators, water miscible organic solvents, additional enzymes, sequesterants, electrolytes, pH regulators, and further auxiliaries, such as optical brighteners, graying inhibitors, color transfer inhibitors, foam regulators, silver corrosion inhibitors, and also dyes and fragrances.
The compositions of the invention may comprise a surfactant or two or more surfactants, suitable surfactants comprising in particular anionic surfactants, nonionic surfactants and mixtures thereof, but also cationic, zwitterionic and amphoteric surfactants.
Suitable anionic surfactants are, in particular, soaps and those containing sulfate or sulfonate groups. Preferred surfactants of the sulfonate type are C9-13 alkylbenzenesulfonates, olefinsulfonates, i.e., mixtures of alkenesulfonates and hydroxyalkanesulfonates, and also disulfonates, as are obtained, for example, from C12-18 monoolefins having a terminal or internal double bond by sulfonating with gaseous sulfur trioxide followed by alkaline or acidic hydrolysis of the sulfonation products. Also suitable are alkanesulfonates, which are obtained from C12-18 alkanes, for example, by sulfochlorination or sulfoxidation with subsequent hydrolysis or neutralization, respectively. Likewise suitable, in addition, are the esters of xcex1-sulfo fatty acids (ester sulfonates), e.g., the xcex1-sulfonated methyl esters of hydrogenated coconut, palm kernel or tallow fatty acids, which are prepared by xcex1-sulfonation of the methyl esters of fatty acids of plant and/or animal origin having 8 to 20 carbon atoms in the fatty acid molecule, followed by neutralization to give water-soluble mono-salts. Preferably, these comprise the xcex1-sulfonated esters of hydrogenated coconut, palm, palm kernel or tallow fatty acids, it being possible as well for sulfonation products of unsaturated fatty acids, e.g. oleic acid, to be present in small amounts, preferably in amounts of not more than about 2 to 3% by weight. Particular preference is given to xcex1-sulfo fatty acid alkyl esters having an alkyl chain of not more than 4 carbon atoms in the ester group, examples being methyl esters, ethyl esters, propyl esters, and butyl esters. With particular advantage, the methyl esters of the xcex1-sulfo fatty acids (MES) are used, and also their saponified di-salts. Further suitable anionic surfactants are sulfated fatty acid glycerol esters which are the monoesters, diesters and triesters, and mixtures thereof, as obtained in the preparation by esterification of a monoglycerol with from 1 to 3 mol of fatty acid or in the transesterification of triglycerides with from 0.3 to 2 mol of glycerol. Preferred alk(en)yl sulfates are the alkali metal salts, and especially the sodium salts, of the sulfuric monoesters of C12-C18 fatty alcohols, examples being those of coconut fatty alcohol, tallow fatty alcohol, lauryl, myristyl, cetyl or stearyl alcohol, or of C10-C20 oxo alcohols, and those monoesters of secondary alcohols of this chain length. Preference is also given to alk(en)yl sulfates of said chain length which contain a synthetic straight-chain alkyl radical prepared on a petrochemical basis, these sulfates possessing degradation properties similar to those of the corresponding compounds based on fatty-chemical raw materials. From a detergents standpoint, C12-C16 alkyl sulfates and C12-C15 alkyl sulfates, and also C14-C15 alkyl sulfates, are particularly preferred. In addition, 2,3-alkyl sulfates, which may for example be prepared in accordance with U.S. Pat. No. 3,234,258 or U.S. Pat. No. 5,075,041 and obtained as commercial products from Shell Oil Company under the name DAN(copyright), are suitable anionic surfactants. Also suitable are the sulfuric monoesters of the straight-chain or branched C7-21 alcohols ethoxylated with from 1 to 6 mol of ethylene oxide, such as 2-methyl-branched C9-11 alcohols containing on average 3.5 mol of ethylene oxide (EO) or C12-18 fatty alcohols containing from 1 to 4 EO. Owing to their high foaming behavior, they are normally used in detergents only in relatively small amounts, for example in amounts of from 1 to 5% by weight. Preferred anionic surfactants further include the salts of alkylsulfosuccinic acid, which are also referred to as sulfosuccinates or as sulfosuccinic esters and which constitute the monoesters and/or diesters of sulfosuccinic acid with alcohols, preferably fatty alcohols and especially ethoxylated fatty alcohols. Preferred sulfosuccinates comprise C8-18 fatty alcohol radicals or mixtures thereof. Especially preferred sulfosuccinates contain a fatty alcohol radical derived from ethoxylated fatty alcohols which themselves represent nonionic surfactants. Particular preference is given in turn to sulfosuccinates whose fatty alcohol radicals are derived from ethoxylated fatty alcohols having a narrowed homolog distribution. Similarly, it is also possible to use alk(en)ylsuccinic acid containing preferably 8 to 18 carbon atoms in the alk(en)yl chain, or salts thereof. Further suitable anionic surfactants include fatty acid derivatives of amino acids, for example, of N-methyltaurine (taurides) and/or of N-methylglycine (sarcosides). Particular preference is given here to sarcosides and to the sarcosinates and, of these, especially the sarcosinates of higher fatty acids, which may be mono- or polyunsaturated, such as oleyl sarcosinate. Further suitable anionic surfactants are, in particular, soaps. Suitable soaps include in particular saturated fatty acid soaps, such as the salts of lauric acid, myristic acid, palmitic acid, stearic acid, hydrogenated erucic acid and behenic acid, and, in particular, mixtures of soaps derived from natural fatty acids, e.g., coconut, palm kernel, or tallow fatty acids. Together with these soaps, or as substitutes for soaps, it is also possible to use the known alkenylsuccinic salts.
The anionic surfactants, including the soaps, may be present in the form of their sodium, potassium or ammonium salts and also as soluble salts of organic bases, such as mono-, di- or triethanolamine. Preferably, the anionic surfactants are in the form of their sodium or potassium salts, in particular in the form of the sodium salts.
Suitable nonionic surfactants are, in particular, alkyl glycosides and ethoxylation and/or propoxylation products of alkyl glycosides or linear or branched alcohols having in each case 12 to 18 carbon atoms in the alkyl moiety and from 3 to 12, preferably from 4 to 10, alkyl ether groups. It is also possible to use corresponding ethoxylation and/or propoxylation products of N-alkylamines, vicinal diols, fatty acid esters and fatty acid amides, which in terms of the alkyl moiety correspond to the aforementioned long chain alcohol derivatives, and also alkylphenols having 5 to 12 carbon atoms in the alkyl radical.
Nonionic surfactants used are preferably alkoxylated, advantageously ethoxylated, especially primary, alcohols having preferably 8 to 18 carbon atoms and on average from 1 to 12 mol of ethylene oxide (EO) per mole of alcohol, in which the alcohol radical may be linear or, preferably, methyl-branched in position 2 land/or may comprise linear and methyl-branched radicals in a mixture, as are commonly present in oxo alcohol radicals. In particular, however, preference is given to alcohol ethoxylates containing linear radicals from alcohols of natural origin having 12 to 18 carbon atoms, e.g., from coconut, palm, tallow fatty or oleyl alcohol and on average from 2 to 8 EO per mole of alcohol. Preferred ethoxylated alcohols include, for example, C12-14 alcohols containing 3 EO or 4 EO, C9-11 alcohols containing 7 EO, C13-15 alcohols containing 3 EO, 5 EO, 7 EO or 8 EO, C12-18 alcohols containing 3 EO, 5 EO or 7 EO, and mixtures thereof, such as mixtures of C12-14 alcohol containing 3 EO and C12-18 alcohol containing 7 EO. The stated degrees of ethoxylation represent statistical mean values, which for a specific product may be an integer or a fraction. Preferred alcohol ethoxylates have a narrowed homolog distribution (narrow range ethoxylates, NREs). In addition to these nonionic surfactants it is also possible to use fatty alcohols containing more than 12 EO. Examples thereof are (tallow) fatty alcohols containing 14 EO, 16 EO, 20 EO, 25 EO, 30 EO or 40 EO. Especially in detergents for use in machine dishwashing processes, it is common to use extremely low-foaming compounds. These include, preferably, C12-C18 alkyl polyethylene glycol-polypropylene glycol ethers having in each case up to 8 mol of ethylene oxide and propylene oxide units in the molecule. However, it is also possible to use other nonionic surfactants which are known to be low-foaming, such as, for example, C12-C18 alkyl polyethylene glycol-polybutylene glycol ethers having in each case up to 8 mol of ethylene oxide and butylene oxide units in the molecule, and also endgroup-capped alkyl polyalkylene glycol mixed ethers. Particular preference is also given to the hydroxyl-containing alkoxylated alcohols as are described in European Patent Application EP 0 300 305, referred to as hydroxy mixed ethers. The nonionic surfactants also include alkyl glycosides of the general formula RO(G)x, where R is a primary straight-chain or methyl-branched aliphatic radical, especially an aliphatic radical methyl-branched in position 2, containing 8 to 22, preferably 12 to 18, carbon atoms, and G represents a glycose unit having 5 or 6 carbon atoms, preferably glucose. The degree of oligomerization, x, which indicates the distribution of monoglycosides and oligoglycosides, is any desired numberxe2x80x94which, as a variable to be determined analytically, may also be a fractionxe2x80x94between 1 and 10; preferably, x is from 1.2 to 1.4. Further suitable surfactants are polyhydroxy fatty acid amides of the formula (I)
where R1CO is an aliphatic acyl radical having 6 to 22 carbon atoms, R2 is hydrogen or an alkyl or hydroxyalkyl radical having 1 to 4 carbon atoms, and [Z] is a linear or branched polyhydroxyalkyl radical having 3 to 10 carbon atoms and from 3 to 10 hydroxyl groups. The polyhydroxy fatty acid amides are derived preferably from reducing sugars having 5 or 6 carbon atoms, especially glucose. The group of the polyhydroxy fatty acid amides also includes compounds of the formula (II)
where R3 is a linear or branched alkyl or alkenyl radical having 7 to 12 carbon atoms, R4 is a linear, branched or cyclic alkylene radical or an arylene radical having 2 to 8 carbon atoms and R5 is a linear, branched or cyclic alkyl radical or an aryl radical or an oxyalkyl radical having 1 to 8 carbon atoms, preference being given to C1-C4 alkyl radicals or phenyl radicals, and [Z] is a linear polyhydroxyalkyl radical whose alkyl chain is substituted by at least two hydroxyl groups, or alkoxylated, preferably ethoxylated or propoxylated, derivatives of said radical. Here too, [Z] is preferably obtained by reductive amination of a sugar such as glucose, fructose, maltose, lactose, galactose, mannose, or xylose. The N-alkoxy- or N-aryloxy-substituted compounds may then be converted to the desired polyhydroxy fatty acid amides, for example, in accordance with the teaching of International Patent Application WO 95/07331 by reaction with fatty acid methyl esters in the presence of an alkoxide as catalyst. A further class of nonionic surfactants used with preference, which are used either as sole nonionic surfactant or in combination with other nonionic surfactants, in particular together with alkoxylated fatty alcohols and/or alkyl glycosides, are alkoxylated, preferably ethoxylated, or ethoxylated and propoxylated, fatty acid alkyl esters, preferably having 1 to 4 carbon atoms in the alkyl chain, especially fatty acid methyl esters, as are described, for example, in Japanese Patent Application JP 58/217598, or those prepared preferably by the process described in International Patent Application WO 90/13533. Nonionic surfactants of the amine oxide type, examples being N-cocoalkyl-N,N-dimethylamine oxide and N-tallowalkyl-N,N-dihydroxyethylamine oxide, and of the fatty acid alkanolamide type, may also be suitable. The amount of these nonionic surfactants is preferably not more than that of the ethoxylated fatty alcohols, in particular not more than half thereof. Further suitable surfactants include those known as gemini surfactants. This term is used generally to refer to those compounds which possess two hydrophilic groups per molecule. These groups are generally separated from one another as a result of what is known as a spacer. This spacer is generally a carbon chain, which should be long enough to give the hydrophilic groups a sufficient spacing to allow them to act independently of one another. Surfactants of this kind are generally notable for an unusually low critical micelle concentration and the ability to reduce greatly the surface tension of water. In exceptional cases, however, the expression gemini surfactants is used to embrace not only dimeric but also, correspondingly, trimeric surfactants. Examples of suitable gemini surfactants are sulfated hydroxy mixed ethers in By accordance with German Patent Application DE 43 21 022 or dimer alcohol bis- and trimer alcohol tris-sulfates and ether sulfates in accordance with German Patent Application DE 195 03 061. Endgroup-capped dimeric and trimeric mixed ethers in accordance with German Patent Application DE-A-195 13 391 are notable in particular for their bi- and multifunctionality. Thus said endgroup-capped surfactants possess good wetting properties and are low-foaming, so making them particularly suitable for use in machine washing or cleaning processes. However, it is also possible to use gemini-polyhydroxy fatty acid amides or polypolyhydroxy fatty acid amides, as described in International Patent Applications WO 95/19953, WO 95/19954, and WO 95/19955.
In laundry detergents of the invention, surfactants are present in proportions of preferably from 5% by weight to 50% by weight, in particular from 8% by weight to 30% by weight, whereas compositions for cleaning hard surfaces, especially for the machine cleaning of kitchen- and tableware, have lower surfactant contents of up to 10% by weight, in particular up to 5% by weight, and preferably in the range from 0.5% by weight to 3% by weight.
A composition of the invention comprises preferably at least one water soluble and/or water insoluble, organic and/or inorganic builder. The water soluble organic builder substances include polycarboxylic acids, especially citric acid and sugar acids, monomeric and polymeric amino polycarboxylic acids, in particular methylglycinediacetic acid, nitrilotriacetic acid and ethylenediaminetetraacetic acid, and also polyaspartic acid, polyphosphonic acids, especially aminotris-(methylenephosphonic acid), ethylenediaminetetrakis-(methylenephosphonic acid) and 1-hydroxyethane-1,1-diphosphonic acid, polymeric hydroxy compounds such as dextrin, and also polymeric (poly)carboxylic acids, especially the polycarboxylates of European Patent EP 0 625 992 or of International Patent Application WO 92/18542 or of European Patent EP 0 232 202, which are obtainable by oxidizing polysaccharides or, respectively, dextrins; polymeric acrylic acids, methacrylic acids, maleic acids and copolymers thereof, which may also contain in copolymerized form small fractions of polymerizable substances without carboxylic acid functionality. The relative molecular mass of the homopolymers of unsaturated carboxyclic acids is generally between 3000 and 200,000, that of the copolymers between 2000 and 200,000, preferably from 30,000 to 120,000, based in each case on free acid. A particularly preferred acrylic acid-maleic acid copolymer has a relative molecular mass of from 30,000 to 100,000. Commercially customary products are, for example, Sokalan(copyright) CP 5, CP 10 and PA 30 from BASF. Suitable though less preferred compounds of this class are copolymers of acrylic acid or methacrylic acid with vinyl ethers, such as vinyl methyl ethers, vinyl esters, ethylene, propylene and styrene, in which the acid fraction is at least 50% by weight. As water soluble organic builder substances it is also possible to use terpolymers containing as monomers two unsaturated acids and/or their salts and, as the third monomer, vinyl alcohol and/or an esterified vinyl alcohol or a carbohydrate. The first acidic monomer or salt thereof is derived from a monoethylenically unsaturated C3-C8 carboxylic acid and, preferably, from a C3-C4 monocarboxylic acid, especially from (meth)acrylic acid. The second acidic monomer or salt thereof may be a derivative of a C4-C8 dicarboxylic acid, maleic acid being particularly preferred, and/or a derivative of an allylsulfonic acid substituted in position 2 by an alkyl or aryl radical. Such polymers may be prepared in particular by processes which are described in German Patent DE 42 21 381 and German Patent Application DE 43 00 772, and generally have a relative molecular mass of between 1000 and 200,000. Further preferred copolymers are those described in German Patent Applications DE 43 03 320 and DE 44 17 734, containing as monomers preferably acrolein and acrylic acid/acrylic acid salts, and/or vinyl acetate. The organic builder substances, especially for the preparation of liquid compositions, may be used in the form of aqueous solutions, preferably aqueous solutions with a strength of from 30 to 50 percent by weight. All said acids are generally used in the form of their water soluble salts, especially their alkali metal salts.
Organic builder substances of this kind may be present, if desired, in amounts of up to 40% by weight, in particular up to 25% by weight, and preferably from 1% by weight to 8% by weight. Amounts close to the stated upper limit are used preferably in pastelike or liquid compositions of the invention, especially those containing water.
Suitable water soluble inorganic builder materials include, in particular, alkali metal silicates, alkali metal carbonates and alkali metal phosphates, which may be present in the form of their alkaline, neutral or acidic sodium or potassium salts. Examples thereof are trisodium phosphate, tetrasodium diphosphate, disodium dihydrogen diphosphate, pentasodium triphosphate, so-called sodium hexametaphosphate, oligomeric trisodium phosphate having degrees of oligomerization from 5 to 1000, especially from 5 to 50, and also the corresponding potassium salts and/or mixtures of sodium and potassium salts. Water insoluble, water dispersible inorganic builder materials used are, in particular, crystalline or amorphous alkali metal alumosilicates, in amounts of up to 50% by weight, preferably not more than 40% by weight, and in liquid compositions in particular from 1% by weight to 5% by weight. Among these, preference is given to the crystalline sodium alumosilicates of detergent quality, especially zeolite A, P and, if appropriate, X, alone or in mixtures, in the form for example of a cocrystallizate of zeolites A and X (Vegobond(copyright) AX, a commercial product from Condea Augusta S.p.A.). Amounts close to the stated upper limit are used preferably in solid, particulate compositions. Suitable alumosilicates possess in particular no particles having a size of more than 30 xcexcm, and preferably consist at least 80% by weight of particles having a size below 10 xcexcm. Their calcium binding capacity, which may be determined in accordance with the information in German Patent DE 24 12 837, is generally in the range from 100 to 200 mg of CaO per gram.
Suitable substitutes or partial substitutes for said alumosilicate are crystalline alkali metal silicates, which may be present alone or in a mixture with amorphous silicates. The alkali metal silicates which can be used as builders in the compositions of the invention preferably have a molar ratio of alkali metal oxide to SiO2 of below 0.95, in particular from 1:1.1 to 1:12, and may be present in amorphous or crystalline form. Preferred alkali metal silicates are the sodium siliates, especially the amorphous sodium silicates, having a molar ratio Na2O:SiO2 of from 1:2 to 1:2.8. Those with a molar ratio Na2O:SiO2 of from 1:1.9 to 1:2.8 may be prepared by the process of European Patent Application EP 0 425 427. As crystalline silicates which may be present alone or in a mixture with amorphous silicates it is preferred to use crystalline phyllosilicates of the general formula Na2SixO2x+1.yH2O, where x, the so-called modulus, is a number from 1.9 to 22, in particular from 1.9 to 4, and y is a number from 0 to 33, and preferred values for x are 2, 3 or 4. Crystalline phyllosilicates which fall under this general formula are described, for example, in European Patent Application EP 0 164 514. Preferred crystalline phyllosilicates are those where x in the stated general formula adopts the values 2 or 3. In particular, both xcex2- and xcex4639-sodium disilicates (Na2Si2O5.yH2O) are preferred, with xcex2-sodium disilicate, for example, being obtainable by the process described in International Patent Application WO 91/08171. xcex4-Sodium silicates having a modulus of between 1.9 and 3.2 may be prepared in accordance with Japanese Patent Applications JP 04/238 809 and JP 04/260 610. In addition, virtually anhydrous crystalline alkali metal silicates of the abovementioned general formula wherein x is a number from 1.9 to 2.1, prepared from amorphous alkali metal silicates, and preparable as described in European Patent Applications EP 0 548 599, EP 0 502 325 and EP 0 452 428, may be used in compositions of the invention. In a further preferred embodiment of compositions of the invention, a crystalline sodium phyllosilicate having a modulus of from 2 to 3 is used, as may be prepared from sand and soda by the process of European Patent Application EP 0 436 835. Crystalline sodium silicates having a modulus in the range from 1.9 to 3.5, as are obtainable by the processes of European Patents EP 0 164 552 and/or EP 0 294 753, are used in a further preferred embodiment of compositions of the invention. Crystalline sheetlike silicates of the abovementioned formula are sold by Clariant GmbH (Germany) under the trade name Na-SKS, e.g., Na-SKS-1 (Na2Si22O45.xH2O, kenyaite), Na-SKS-2 (Na2Si14O29.xH2O, magadiite), Na-SKS-3 (Na2Si8O17.xH2O) or Na-SKS-4 (Na2Si4O9.xH2O, makatite). Of these, those particularly suitable include Na-SKS-5 (xcex1-Na2Si2O5), Na-SKS-7 (xcex2-Na2Si2O5, natrosilite), Na-SKS-9 (NaHSi2O5.H2O), Na-SKS-10 (NaHSi2O5.3H2O, kanemite), Na-SKS-11 (t-Na2Si2O5) and Na-SKS-13 (NaHSi2O5), but especially Na-SKS-6 (xcex4-Na2Si2O5). A review of crystalline phyllosilicates is given, for example, by the articles published in xe2x80x9cHoechst High Chem Magazin 14/1993xe2x80x9d on pages 33-38 and in xe2x80x9cSeifen-xc3x96le-Fette-Wachse, Vol. 116, No. 20/1990xe2x80x9d on pages 805-808. In one preferred embodiment of compositions of the invention, use is made of a granular compound of crystalline phyllosilicate and citrate, of crystalline phyllosilicate and abovementioned (co)polymeric polycarboxylic acid, as is described, for example, in German Patent Application DE 198 19 187, or of alkali metal silicate and alkali metal carbonate, as is described, for example, in International Patent Application WO 95/22592 or as is available commercially, for example, under the name Nabion(copyright) 15.
Builder substances may be present in the compositions of the invention, if desired, in amounts of up to 90% by weight. They are preferably present in amounts of up to 75% by weight. Laundry detergents of the invention have builder contents of in particular from 5% by weight to 50% by weight. In compositions of the invention for cleaning hard surfaces, especially for the machine cleaning of kitchen- and tableware, the amount of builder substances is in particular from 5% by weight to 88% by weight, preferably no water insoluble builder materials being used in such compositions. In a preferred embodiment of compositions of the invention intended in particular for the machine washing of kitchen- and tableware, from 20% by weight to 40% by weight of water soluble organic builder, especially alkali metal citrate, from 5% by weight to 15% by weight of alkali metal carbonate, and from 20% by weight to 40% by weight of alkali metal disilicate are present.
Peroxygen compounds suitable for use in compositions of the invention include, in particular, organic peracids or peracidic salts of organic acids, such as phthalimidopercaproic acid, perbenzoic acid or salts of diperdodecanedioic acid, hydrogen peroxide, and inorganic salts which give off hydrogen peroxide under the washing conditions, including perborate, percarbonate, persilicate and/or persulfate such as Caroate. Where solid peroxygen compounds are to be used, they may be employed in the form of powders or granules, which may also have been coated in a manner which is known in principle. Where a composition of the invention does comprise peroxygen compounds, they are present in amounts of preferably up to 50% by weight, in particular from 5% by weight to 30% by weight. The addition of small amounts of known bleach stabilizers such as, for example, of phosphonates, borates and/or metaborates and metasilicates, and also magnesium salts such as magnesium sulfate, may be judicious.
Bleach activators which may be used are compounds which under perhydrolysis conditions give rise to aliphatic peroxo carboxylic acids having preferably 1 to 10 carbon atoms, in particular 2 to 4 carbon atoms, and/or substituted or unsubstituted perbenzoic acid. Suitable substances are those which carry O-acyl and/or N-acyl groups of the stated number of carbon atoms, and/or substituted or unsubstituted benzoyl groups. Preference is given to polyacylated alkylenediamines, especially tetraacetylethylenediamine (TAED), acylated triazine derivatives, especially 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT), acylated glycolurils, especially tetraacetylglycoluril (TAGU), N-acyl imides, especially N-nonanoylsuccinimide (NOSI), acylated phenolsulfonates, especially n-nonanoyl- or isononanoyloxybenzenesulfonate (n- or iso-NOBS), carboxylic anhydrides, especially phthalic anhydride, acylated polyhydric alcohols, especially triacetin, ethylene glycol diacetate, 2,5-diacetoxy-2,5-dihydrofuran, and the enol esters known from German Patent Applications DE 196 16 693 and DE 196 16 767, and also acetylated sorbitol and mannitol and/or the mixtures thereof (SORMAN) described in European Patent Application EP 0 525 239, acylated sugar derivatives, especially pentaacetylglucose (PAG), pentaacetyl-fructose, tetraacetylxylose and octaacetyllactose, and acetylated, optionally N-alkylated glucamine and gluconolactone, and/or N-acylated lactams, for example, N-benzoylcaprolactam, which are known from International Patent Applications WO 94/27970, WO 94/28102, WO 94/28103, WO 95/00626, WO 95/14759 and WO 95/17498. The hydrophilically substituted acylacetals known from German Patent Application DE 196 16 769 and acyllactams described in German Patent Application DE 196 16 770 and in International Patent Application WO 95/14075 are likewise used with preference. The combinations of conventional bleach activators known from German Patent Application DE 44 43 177, may also be used. Such bleach activators may be present in customary quantities, preferably in amounts of from 0.5% by weight to 10% by weight, and in particular from 1% by weight to 8% by weight, based on overall composition.
In addition to the above-listed conventional bleach activators, or instead of them, it is also possible for the sulfonimines known from European Patents EP 0 446 982 and EP 0 453 003 and/or bleach boosting transition metal salts or transition metal complexes to be present as so-called bleaching catalysts.
Enzymes which may be used in the compositions in addition to the protease/amylase combination that is essential to the invention include those from the class of the lipases, cutinases, pullulanases, hemicellulases, cellulases, oxidases, laccases and peroxidases, and mixtures thereof. If desired, proteases or amylases other than the protease or amylase essential to the invention may be present in addition to the latter. Particularly suitable active enzymatic substances are those obtained from fungi or bacteria, such as Bacillus subtilis, Bacillus licheniformis, Streptomyces griseus, Humicola lanuginosa, Humicola insolens, Pseudomonas pseudoalcaligenes, Pseudomonas cepacia or Coprinus cinereus. The enzymes that may be used in addition mayxe2x80x94as described, for example, in International Patent Application WO 92/11347 or WO 94/23005xe2x80x94be adsorbed on carrier substances and/or embedded in coating substances in order to protect them against premature inactivation. In the detergents of the invention they are present preferably in amounts of up to 5% by weight, in particular from 0.2% by weight to 4% by weight.
The organic solvents which may be used besides water in the compositions of the invention, especially if they are present in liquid or paste form, include alcohols having 1 to 4 carbon atoms, especially methanol, ethanol, isopropanol and tert-butanol, diols having 2 to 4 carbon atoms, especially ethylene glycol and propylene glycol, and also mixtures thereof and the ethers derivable from the aforementioned classes of compound. Water miscible solvents of this kind are present in the compositions of the invention preferably in amounts of not more than 30% by weight, in particular from 6% by weight to 20% by weight.
Additionally, the compositions may comprise further constituents customary in detergents. These optional constituents include, in particular, enzyme stabilizers, graying inhibitors, color transfer inhibitors, foam inhibitors, and optical brighteners and also dyes and fragrances. In order to protect against silver corrosion, silver corrosion inhibitors may be used in dishwashing detergents of the invention. A cleaning product of the invention for hard surfaces may, furthermore, comprise abrasive constituents, especially from the group consisting of quartz flours, wood flours, polymer flours, chalks and glass microbeads, and mixtures thereof. Abrasives are present in the detergents of the invention preferably at not more than 20% by weight, in particular from 5% by weight to 15% by weight.
In order to adjust the pH to a desired level which does not come about of itself through the mixing of the other components, the compositions of the invention may comprise system-compatible and environmentally compatible acids, especially citric acid, acetic acid, tartaric acid, malic acid, lactic acid, glycolic acid, succinic acid, glutaric acid and/or adipic acid, or else mineral acids, especially sulfuric acid, or bases, especially ammonium hydroxides or alkali metal hydroxides. pH regulators of this kind are present in the compositions of the invention in amounts of preferably not more than 20% by weight, in particular from 1.2% by weight to 17% by weight.
The color transfer inhibitors suitable for use in laundry detergents of the invention include, in particular, polyvinylpyrrolidones, polyvinylimidazoles, polymeric N-oxides such as poly(vinylpyridine N-oxide), and copolymers of vinylpyrrolidone with vinylimidazole.
Graying inhibitors have the function of keeping the soil detached from the textile fiber in suspension in the liquor. Suitable for this purpose are water soluble colloids, usually organic in nature, examples being starch, glue, gelatin, salts of ether carboxylic acids or ether sulfonic acids of starch or of cellulose, or salts of acidic sulfuric esters of cellulose or of starch. Water soluble polyamides containing acidic groups are also suitable for this purpose. Furthermore, starch derivatives other than those mentioned above may be used, aldehyde starches, for example. Preference is given to cellulose ethers, such as carboxymethylcellulose (Na salt), methylcellulose, hydroxyalkylcellulose and mixed ethers, such as methylhydroxyethylcellulose, methylhydroxypropylcellulose, methylcarboxymethylcellulose, and mixtures thereof, in amounts, for example, of from 0.1 to 5% by weight, based on the compositions.
As optical brighteners, laundry detergents of the invention may comprise derivatives of diaminostilbene-disulfonic acid and/or its alkali metal salts. Suitable, for example, are salts of 4,4xe2x80x2-bis(2-anilino-4-morpholino-1,3,5-triazinyl-6-amino)stilbene-2,2xe2x80x2-disulfonic acid or compounds of similar structure which instead of the morpholino group carry a diethanolamino group, a methylamino group, an anilino group, or a 2-methoxyethylamino group. It is also possible for brighteners of the substituted diphenylstyryl type to be present, for example, the alkali metal salts of 4,4xe2x80x2-bis(2-sulfostyryl)biphenyl, 4,4xe2x80x2-bis(4-chloro-3-sulfostyryl)biphenyl, or 4-(4-chlorostyryl)-4xe2x80x2-(2-sulfostyryl)biphenyl. Mixtures of the aforementioned optical brighteners may also be used.
Especially for use in machine processes, it may be of advantage to add customary foam inhibitors to the compositions. Examples of suitable foam inhibitors are soaps of natural or synthetic origin having a high C18-C24 fatty acid fraction. Examples of suitable nonsurfactant-type foam inhibitors are organo-polysiloxanes and their mixtures with microfine, optionally silanized silica and also paraffins, waxes, microcrystalline waxes, and mixtures thereof with silanized silica or bis-fatty acid alkylene diamides. With advantages, use is also made of mixtures of different foam inhibitors, for example, mixtures comprising silicones, paraffins, or waxes. The foam inhibitors, especially those containing silicone and/or paraffin, are preferably bound on a granular, water soluble or dispersible support substance. Particular preference is given to mixtures of paraffins and bisstearylethylenediamide.
The production of solid compositions of the invention presents no difficulties and may be done conventionally, for example, by spray drying or granulation, with the enzymes and any other heat sensitive ingredients such as bleaches, for example, being added separately later on if desired. To produce compositions of the invention of heightened bulk density, in particular in the range from 650 g/l to 950 g/l, preference is given to a process known from European Patent EP 0 486 592 which includes an extrusion step. Another preferred preparation, with the aid of a granulation process, is described in European Patent EP 0 642 576.
To produce compositions of the invention in tablet form, which may have one or more phases, may have one or more colors, and consist in particular of one layer or of two or more layers, in particular of two layers, it is preferred to follow a procedure in which all of the constituentsxe2x80x94per one layer if appropriatexe2x80x94are mixed with one another in a mixer and the mixture is compressed by means of conventional tableting presses, for example, eccentric presses or rotary presses, at pressing forces in the range from about 50 to 100 kN, preferably from 60 to 70 kN. Especially in the case of multilayer tablets it may be of advantage if at least one layer is compressed beforehand. This is preferably accomplished at pressing forces of between 5 and 20 kN, in particular from 10 to 15 kN. In this way, tablets which are fracture resistant and yet dissolve sufficiently quickly under application conditions are obtained without problems, having fracture strengths and flexural strengths of normally from 100 to 200 N, but preferably above 150 N. A tablet produced in this way preferably has a weight of from 10 g to 50 g, in particular from 15 g to 40 g. The three-dimensional form of the tablets is arbitrary and may be circular, oval or angular, with intermediate forms also being possible. Corners and edges are advantageously rounded. Circular tablets preferably have a diameter of from 30 mm to 40 mm. In particular, the size of tablets of angular or cuboid design which are introduced predominantly by way of the dosing apparatus of, for example, the dishwashing machine is dependent on the geometry and on the volume of this dosing apparatus. Embodiments which are preferred by way of example have a basal area of (from 20 to 30 mm)xc3x97(from 34 to 40 mm), in particular of 26xc3x9736 mm or of 24xc3x9738 mm.
Liquid or paste detergents of the invention in the form of solutions comprising customary solvents are generally prepared by simply mixing the ingredients, which may be introduced in bulk or in solution into an automatic mixer.

Detergents containing amylase and protease


A test, drill and pull system for testing a well formation or zone of interest and further drilling of the well in a single trip into the wellbore. The system includes a surface readout tester valve, a rotation-operated reversing valve, a resettable packer, a packer lockout, a perforated anchor and a drill bit. In operation, the apparatus is run into the bottom of the well adjacent to the formation or zone of interest and the packer set and unset as desired. With the packer set, a surface readout tester valve probe is lowered into the apparatus on a wireline and latched into the tester valve so that multiple testing operations may be carried out if desired. After testing, the fluid recovery may be reversed out and analyzed by actuating the reversing valve by rotation of the tool string. Further, rotation engages the packer lockout such that when weight is picked upon the packer, the packer cannot be reset. After the packer lockout is engaged and the packer unset, further drilling operations may be carried out without removing the apparatus from the wellbore.

1. Field of the Invention
The present invention relates generally to apparatus and methods for servicing a well, and more particularly, to apparatus and methods for the early evaluation of a well after the borehole has been partially drilled and before casing has been cemented in the borehole such that testing of the well and further drilling may be carried out on a single trip of the tool into the well.
2. Description of the Prior Art
During the drilling and completion of oil and gas wells, it is often necessary to test or evaluate the production capabilities of the well. This is typically done by isolating a subsurface formation or a portion of a zone of interest which is to be tested and subsequently flowing a sample of well fluid either into a sample chamber or up through a tubing string to the surface. Various data, such as pressure and temperature of the produced well fluids, may be monitored downhole to evaluate the long-term production characteristics of the formation.
One commonly used well testing procedure is to first cement a casing in the wellbore and then to perforate the casing adjacent the formation or zone of interest. Subsequently, the well is flow-tested through the perforations. Such flow tests are commonly carried out with a drill stem test string located within the casing. The drill stem test string carries packers, tester valves, circulating valves and the like to control the flow of fluids through the drill stem test string.
Although drill stem testing of cased wells provides very good test data, it has the disadvantage that the well must first be cased before the test can be conducted. Also, better reservoir data can often be obtained immediately after the well is drilled and before the formation has been severely damaged by drilling fluids and the like.
For these reasons, it is often desired to evaluate the potential production capability of a well without incurring the cost and delay of casing the well. This has led to a number of attempts at developing a successful open-hole test which can be conducted in an uncased borehole.
One approach which as been used for open-hole testing is the use of a weight-set, open-hole compression packer on a drill stem test string. To operate a weight-set, open-hole compression packer, a solid surface must be provided against which the weight can be set. Historically, this is accomplished by a perforated anchor which sets down on the bottom. Prior to such drill stem testing, it is necessary to remove the drill string from the well and then run the test string into the well. Afterwards, if it is desired to further drill the well, the test string must be removed so that the drill string may be run back into the well for the additional drilling procedure.
Thus, there is a need for reducing the number of trips in and out of the well which reduces both the cost of testing and drilling and also allows the testing to be conducted at an early stage before significant damage is done to the formation or zone of interest. The present invention meets these needs by providing a testing system which allows an open-hole test to be carried out and then additional drilling to be done on the same trip into the well.
The present invention includes a well testing system and method of testing and drilling a well. Specifically, the apparatus is referred to as a test, drill and pull tool. This apparatus is adapted for use on a tool or drill string for testing in an uncased wellbore.
The apparatus comprises a packer having a set position for sealing engagement with the wellbore and packer and an unset position for disengagement from the wellbore, a tester valve in communication with the drill string and having an open position such that fluid from the well will flow into the drill string during a well test when the packer is set and further having a closed position, and a drill bit adapted for further drilling of the well after the packer lockout has been engaged. The packer is preferably a compression or squeeze packer which is set by setting down weight on the drill string and unset by picking up the drill string, the packer being resettable in this way without removal from the wellbore.
The apparatus may also comprise a packer lockout having an engaged position which prevents resetting of the packer when weight is set down on the drill string and packer after the packer has been set and subsequently unset. The packer lockout is preferably engaged by rotation of the drill string. When this packer lockout is engaged, the drill bit may be rotated. In one embodiment, the drill bit may be rotated by rotating the drill string, and in another embodiment, the drill bit may be rotated by a mud motor actuated by pumping mud down the drill pipe.
The tester valve may be a surface readout tester valve, and the apparatus may further comprise a valve probe latchably engagable with the tester valve. In the illustrated embodiment, the valve probe is connectable to a wireline on which the valve probe may be run into the wellbore and engaged with the tester valve. Pulling on the wireline will open the tester valve for the test, and slacking off on the wireline will close the tester valve. The valve probe may further comprise a sampler adapted for trapping a fluid sample during the well test and/or a flow meter or xe2x80x9cspinnerxe2x80x9d for determining fluid flow rates therethrough during the well test.
The setting and unsetting of the packer and the testing of the well with a tester valve may be carried out any number of times as desired prior to actuation of the packer lockout.
The apparatus may also comprise an isolation valve in communication with the drill string and having a closed position for testing the well and an open position wherein the drill string is placed in communication with the well during a drilling operation. The isolation valve may be actuated by rotation of the drill string, or alternatively, the isolation valve may be configured such that it is pressure actuated.
The apparatus additionally comprises a perforated anchor between the packer and drill bit. The perforated anchor is in communication with the tester valve, and fluid may flow through the perforated anchor into the drill string during a well test. A check valve is provided in the anchor and adapted for allowing fluid to enter the drill string during the well test and preventing discharge of fluid from the anchor during a drilling operation with the drill bit.
Stated in another way, the apparatus of the present invention is adapted for use on a drill string in an uncased wellbore and comprises a packer having a set position for sealing engagement with the wellbore and an unset position disengaged from the wellbore, a tester valve in communication with the drill string and having an open position and a closed position, a valve probe connectable to the tester valve for actuating the tester valve between the open and closed positions thereof, and a drill bit adapted for further drilling of the wellbore. The packer is adapted such that, after a selected cycle of setting and unsetting of the packer, it cannot be reset, and the drill bit is adapted for further drilling after the selected cycle of setting and unsetting the packer. The prevention of resetting of the packer is preferably accomplished by a packer lockout which prevents resetting of the packer after the selected cycle of setting and unsetting the packer.
The invention also includes a method of testing and drilling a well which comprises the step of running a tool string into the well and positioning the tool string adjacent to a bottom portion of the well. This tool string comprises a length of drill pipe, a packer connected to the drill pipe, a tester valve, and a drill bit. The method further comprises the steps of setting the packer into sealing engagement with an uncased borehole of the well, opening the tester valve so that the fluid will flow from a formation or zone of interest into the tool string, closing the tester valve, locking the packer such that it cannot be reset, unsetting the packer, drilling the well deeper with the drill bit.
The step of opening the tester valve may comprise flowing fluid into the drill pipe and flowing at least a sample portion of the fluid through the drill pipe to the surface of the well.
After the step of closing the tester valve, and before the step of locking the packer, the method may further comprise repeating the steps of opening the tester valve and closing the tester valve as many times as desired. After the step of closing the tester valve, and before the step of locking the packer, the method may also comprise unsetting the packer and repeating the steps of setting the packer, opening the tester valve and closing the tester valve as many times as desired. The method may further comprise running the tool string out of the well, unlocking the packer, and repeating the previously mentioned steps.
The step of locking the packer may comprise actuating a packer lockout in the tool string, and in the preferred embodiment, this step is carried out by rotating the tool string.
The method of testing and drilling a well may further comprise the steps of running a valve probe into the drill string on a wireline, and latching the valve probe to the tester valve. The step of opening the tester valve comprises applying tension to the wireline, and the step of closing the tester valve comprises slacking off on the wireline.
During the step of drilling, fluid is pumped down the tool string while preventing flow of fluid from the well into the tool string. Drilling may be accomplished by rotating the tool string or pumping the fluid through a mud motor connected to the drill bit.
Additionally, the method may comprise trapping a fluid sample while fluid is flowing from the formation or zone of interest and/or measuring a flow rate of the fluid flowing from the formation or zone of interest.
Numerous objects and advantages of the invention will become apparent as the following description of the preferred embodiment is read in conjunction with the drawings which illustrate such embodiment.

Test, drill and pull system and method of testing and drilling a well


An abrasive cleaning composition comprises abrasive particles, preferable of a soluble abrasive, cationic or non ionic surfactants and a quaternary ammonium antibacterial agent.

The present invention relates to cleaning compositions, and in particular to cleaning compositions containing abrasive particles.
Cleaning compositions containing abrasive particles are well known and may generally be classified into two types. The first type contain water-insoluble abrasive particles. These particles are often difficult to rinse away from the cleaned surface and can leave an undesirable gritty residue on the surface. In order to overcome these disadvantages, the second type of composition has been proposed in which the abrasive particles are water soluble. These compositions contain the water-soluble abrasive particles in an amount greater than that required to achieve a saturated solution. Thus, undissolved abrasive particles are always present in the composition. Because the abrasive particles are water soluble, particles remaining on the surface after cleaning tend to be dissolved on rinsing the surface and are thus removed from the surface. Cleaning compositions containing water soluble abrasive particles are described in EP 0 193 375 and WO 91/08282.
Cleaning compositions of this general type are particularly suitable for cleaning hard surfaces especially in kitchens and bathrooms such as sinks, washbasins, baths, shower trays and stalls, lavatories, work surfaces and the like. In these uses, the concept of good hygiene is particularly important to consumers and to meet this need, abrasive cleaning compositions having soluble or insoluble abrasive particles and further including a chlorine containing, in particular a hypochlorite containing bleach, have been proposed. The hypochlorite bleach is included in the compositions to provide, inter alia, an antibacterial effect. U.S. Pat. No. 3,577,347 describes a composition consisting of anionic and non-ionic detergents, a chlorine bleaching compound and more than 50% by weight of a water soluble abrasive salt having less than six molecules of water of hydration and selected from alkali and alkaline earth metal salts. As is well known, the inclusion of chlorine containing bleaches in cleaning compositions causes significant formulation problems with regard, in particular, to the stability of the composition and the thickening of the composition. Furthermore, chlorine containing bleaches are often perceived by the consumer as xe2x80x9caggressivexe2x80x9d or xe2x80x9charshxe2x80x9d and may easily damage clothes, soft furnishings and the like.
Accordingly, the present invention seeks to overcome the above disadvantages and to provide a cleaning composition containing an abrasive, especially a water-soluble abrasive which composition also has antibacterial properties, without requiring the incorporation of bleaching agents.
Two further relevant prior art documents are as follows.
U.S. Pat. No. 3,997,460 describes a surface adherent abrasive liquid cleaner including a mineral acid to aid in dissolving stains and an abrasive suspended in the cleaner to aid in mechanically scrubbing off stains.
U.S. Pat. No. 4,561,993 describes a thixotropic cleaner comprising about 6 to 12% of precipitated silica, about 0.05 to 2.5 of a cationic, nonionic, zwitteronic or amphoteric surfactant or mixtures thereof that has the ability to hydrogen bond, an acid and an abrasive.
One known method of providing antibacterial properties in a cleaning composition is to include in the composition a quaternary ammonium type antibacterial agent. Such quaternary ammonium compounds are included in known (non-abrasive) antibacterial hard surface cleaners. However, the inclusion of quaternary ammonium antibacterial agents presents disadvantages in formulating cleaning compositions. For example, due to the cationic nature of the quaternary ammonium compounds, conventional anionic surfactants or surfactant mixtures containing anionic surfactants cannot be used. Also, the inclusion of quaternary ammonium compounds often presents formulations difficulties with thickening media such as polyacrylates and synthetic or natural clays such as Laponite (TM) and some Bentonite types. Furthermore, it has commonly been supposed that the cationic quaternary ammonium compounds would become absorbed on anionic sites of the abrasive particles, thereby significantly reducing or rendering ineffective the antibacterial properties of these compounds.
However it has now been shown that useful antibacterial properties can be obtained from hard surface cleaning compositions containing both quaternary ammonium compounds and abrasive particles, in particular particles of a soluble abrasive material. Accordingly, the present invention provides an aqueous antibacterial abrasive cleaning composition comprising, in addition to water,
8% to 80% of abrasive particles,
0.5% to 25% of a cationic or non-ionic surfactant,
0.1% to 10% of a quaternary ammonium antibacterial agent,
0% to 15% of a solvent, and a functional amount of a thickening agent,
wherein the abrasive particles are soluble in the composition and are present in an amount in excess of their saturation solubility.
Preferably the abrasive particles are water-soluble abrasive particles is selected from inorganic or organic water soluble salts of alkali or alkaline earth metals. They are present in the composition in an amount such that at least 5% of the particles (by weight of the composition)remain undissolved.
Preferred abrasive particles include sodium carbonate, sodium bicarbonate, sodium sesquicarbonate sodium tripolyphosphate pentahydrate, sodium tetraborate decahydrate, potassium sulphate and sodium citrate. Additionally or alternatively, other water soluble salts may be included, such as sodium chloride, potassium chloride, magnesium chloride, calcium chloride and other inorganic or organic water soluble salts of lithium, magnesium, sodium, potassium and calcium, of which sodium oxalate, sodium succinate, sodium adipate and sodium glutarate are examples.
As indicated above, the soluble abrasive particles must be present in an amount in excess of the saturation solubility, so that in the composition the soluble salt comprising the abrasive particles is present in both the dissolved and the undissolved state. Preferably, the salt is present in total in an amount of 15% to 60%, particularly 30% to 50%, and especially about 40% by weight of the composition.
One of the criteria used in selecting the abrasive particles is the hardness of the particles. The particles should have a hardness less than that of the surfaces to be cleaned, in order to avoid scratching the surfaces. Thus, the particles will usually have a hardness less than that of plastic, for example acrylic, baths and like materials. A Mohs hardness of at least 2 and less than 4, preferably less than 3 will in general be suitable.
In order to provide the necessary abrasive properties, the abrasive particles will usually have a mean particle diameter of from 5 mm to 500 mm, and preferably from 10 mm to 300 mm. The mean particle diameter may also have an effect on the ability of compositions to maintain the abrasive particles in suspension, and also on the cleaning efficacy.
It is important that the compositions of the invention are stable in use and storage so that the abrasive particles remain in suspension. It may usually be expected that the compositions will be stored and used at temperatures generally within the range of 0xc2x0 C. to 40xc2x0 C. It is therefore preferable to choose salts for the abrasive particles whose saturation solubility changes to the minimum extent over this temperature range. Particularly, it is preferable that the saturation solubility of the salt in water at 40xc2x0 C. is less than 10 times, most preferably less than 8 times, and especially less than 2 times that at 10xc2x0 C. Suitable salts will typically have a solubility in the range of from about 2 g to about 70 g per 100ml of water and 0xc2x0 C. and from about 4 g to about 150 g per 100ml of water at 40xc2x0 C. More preferably the salts will have a solubility in the range of from about 3 g to about 70 g per 100 ml of water at 0xc2x0 C. and from about 4 g to about 90 g per 100 ml of water at 40xc2x0 C. and especially from about 8 g to about 35 g per 100 ml at 0xc2x0 C. and from about 12 g to about 40 g per 100 ml of water at 40xc2x0 C.
To ensure that the composition contains undissolved abrasive particles, the salt forming the abrasive particles will preferably have a saturation solubility at 10xc2x0 C. of not more than 15% by weight. In order to ensure that the abrasive particles may easily be rinsed from the surface after cleaning, the salt will preferably have a solubility in water of at least 5 g/l at 10xc2x0 C.
The compositions of the invention will preferably have a pH in the range from pH 5 to pH 12, more preferably from pH 7 to pH 12 and especially from pH 8 to pH 12.
Of the above mentioned salts, sodium bicarbonate meets the above-noted criteria particularly well and is preferred in the present invention.
The quaternary ammonium antibacterial agents used in the present invention may in general be selected from those known in the art. Suitable examples include quarternary ammonium compounds and salts thereof which may be characterised by the general structural formula:
where at least one R1, R2, R3 and R4 is a hydrophobic, aliphatic, aryl aliphatic or aliphatic aryl radical of from 6 to 26 carbon atoms, and the entire cation portion of the molecule has a molecular weight of at least 165. The hydrophobic radicals may be long-chain alkyl, long-chain alkoxy aryl, long-chain alkyl aryl, halogen-substitued long-chain alkyl aryl, long-chain alkyl phenoxy alkyl, aryl alkyl, etc. The remaining radicals on the nitrogen atoms other than the hydrophobic radicals are substituents of a hydrocarbon structure usually containing a total of no more than 12 carbon atoms. The radicals R1, R2, R3 and R4 may be straight chained or may be branched, but are preferably straight chained, and may include one or more amide or ester linkages. The radical X may be any salt-forming anionic radical.
Exemplary quaternary ammonium salts within the above description include the alkyl ammonium halides such as decyl trimethyl ammonium chloride, decyl dimethyl benzyl ammonium chloride, lauryl trimethyl ammonium chloride, lauryl dimethyl benzyl ammonium chloride, myristyl trimethyl ammonium chloride, myristyl dimethyl benzyl ammonium chloride, myristyl trimethyl ammonium bromide, cetyl trimethyl ammonium chloride, cetyl trimethyl ammonium bromide, dioctyl dimethyl ammonium chloride, didecyl dimethyl ammonium chloride and dilauryl dimethyl ammonium chloride, alkyl aryl ammonium halides such as octadecyl dimethyl benzyl ammonium bromide, N-alkyl pyridinium halides such as N-cetyl pyridinium bromide, and the like. Other suitable types of quarternary ammonium salts include those in which the molecule contains either amide or ester linkages such as octyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride, N-(laurylcocoaminoformlmethyl)-pyridinium chloride, and the like. Other very effective types of quarternary ammonium compounds which are useful as antibacterial agents include those in which the hydrophobic radical is characterised by a substituted aromatic nucleus as in the case of lauryloxyphenyltrimethyl ammonium chloride, cetyl aminophenyltrimethyl ammonium methosulfate, dodecyl phenyltrimethyl ammonium methosulfate, dodecylbenzyl trimethyl ammonium chloride, chlorinated dodecylbenzyltrimethyl ammonium chloride, and the like.
Preferred quaternary ammonium compounds which act as antibacterial agents and which are be found useful in the practice of the present invention include those which have the structural formula:
wherein R2 and R3 are the same or different C8-C12 alkyl groups, or R2 is C12-16 alkyl, C8-18 alkylethoxy, C8-18 alkylphenolethoxy group and R3 is a benzyl group and X may be any salt-forming anionic radical, but is preferably a halide, such as a chloride, bromide or iodide, or is a methosulfate radical. The alkyl groups recited in R2 and R3 may be straight chained or branched, but are preferably substantially linear.
Such quatenary ammonium antibacterial agents are usually sold as mixtures of two or more different quatenaries, such as BARDAC 205M (presently commercially available from Lonza, UK Ltd) which is believed to be a 50% aqueous solution containing 20% by weight of an alkyl dimethyl benzylammonium chloride (50% C14, 40% C16 alkyl); 15% by weight of an octyl decyl dimethylammonium chloride; 7.5% by weight of dioctyl dimethylammonium chloride; and 7.5% by weight of didecyl dimethylammonium chloride. A further useful quarternary ammonium antibacterial agent is CYNCAL(copyright) 80% (presently commercially available from Hilton Davis Chemical Co.;) which is believed to comprise 80% by weight of an alkyl dimethyl benzylammonium chloride (50% C14, 40% C12 and 10% C16 alkyl), 10% water and 10% ethanol. Further useful quaternary ammonium antibacterial agents include BTC-8358(copyright), an alkyl benzyl dimethyl ammonium chloride (80% active) and BTC-818(copyright), a dialkyl dimethyl ammonium chloride (both presently commercially available from the Millchem UK Ltd). Additional suitable commercially available quaternary ammonium antibacterial agents of the alkyl dimethyl benzyl ammonium chloride type containing the same dimethyl benzyl ammonium chloride mixture as that of CYNCAL(copyright) and which are generally referred to as quarternium salts include BARQUAT(copyright) MB-80, (presently commercially available from Lonza, UK Ltd.) which is believed to be an 80% by weight solution (20% ethanol) of the quarternary, HYAMINE 1622 believed to be an aqueous solution of benzethonium chloride and HYAMINE 3500, which is believed to be a 50% aqueous solution of the quarternary (both presently commercially available from Lonza UK, Ltd).
Preferably, the quaternary ammonium antibacterial agent is present in an amount of from 0.1% to 4%.
Suitable nonionic surfactants which can be used in the instant invention include water soluble nonionic surfactants, many of which are well known and conventionally used in the art. Nonlimiting examples of nonionic surfactants which may be employed in the composition include those which are water soluble or water miscible and include one or more of the following: amine oxides, block copolymers, alkoxylated alkanolamides, ethoxylated alcohols, and ethoxylated alkyl phenols, and the like. Other commercially available nonionic surfactants may be found in the xe2x80x9cChemical Classificationxe2x80x9d section of McCutcheon""s Emulsifier and Detergents North American Edition, 1991 and also in Surfactants Europa, 3rd edn. Hollis (Ed) 1995.
Useful water soluble nonionic surfactants in the compositions according to the present invention include commercially well known surfactant compositions, including the primary aliphatic alcohol ethoxylates, secondary aliphatic alcohol ethoxylates, alkylphenol ethoxylates and ethylene-oxide-propylene oxide condensates of primary alkanols. These water soluble nonionic surfactants are generally the condensation products of an organic aliphatic or alkyl aromatic hydrophobic compound and hydrophilic ethylene oxide groups. Practically any hydrophobic compound having a carboxy, hydroxy, amido, or amino group with a free hydrogen attached to the nitrogen can be condensed with a hydrophilic group containing an ethylene oxide and/or the polyhydration product thereof, polyethylene glycol, to form a water soluble nonionic surfactant.
Useful nonionic surfactants include the condensation products of a higher alcohol (e.g. an alkanol containing about 8 to 18 carbon atoms in a straight or branched chain configuration) condensed with about 5 to 30 moles of ethylene oxide, for example, lauryl or myristyl alcohol condensed with about 16 moles of ethylene oxide, tridecanol condensed with about 6 to 10 moles of ethylene oxide, myristyl alcohol condensed with about 10 moles of ethylene oxide per mole of myristyl alcohol, the condensation product of ethylene oxide with a cut of coconut fatty alcohol containing a mixture of fatty alcohols with alkyl chains varying from 10 to about 14 carbon atoms in length and wherein the condensate contains either about 6 moles of ethylene oxide per mole of total alcohol or about 9 moles of ethylene oxide per mole of alcohol and tallow alcohol ethoxylates containing 6 moles ethylene oxide to 11 moles ethylene oxide per mole of alcohol.
A preferred group of the foregoing nonionic surfactants are certain ethoxylates presently commercially available under the trade name Neodol(copyright) (Shell Chemical) which are believed to be higher aliphatic, primary alcohols containing about 9-15 carbon atoms, such as C9-C11 alkanol condensed with 8 moles of ethylene oxide (Neodol 91-8), C12-13 alkanol condensed with 6.5 moles ethylene oxide (Neodol(copyright) 23-6.5), C12-15 alkanol condensed with 12 moles ethylene oxide (Neodol(copyright) 25-12), C14-15 alkanol condensed with 13 moles ethylene oxide (Neodol(copyright) 45-13), and the like. Such ethoxylates have an HLB (hydrophobic to lipophilic balance) value of about 8 to 15 and give good oil/water emulsification, whereas ethoxylates with HLB values below 8 contain less than 5 ethylene oxide groups and tend to be poor emulsifiers and poor detergents.
Additional satisfactory nonionic surfactant compositions include the condensation products of a secondary aliphatic alcohols containing 8 to 18 carbon atoms in a straight or branched chain configuration condensed with 5 to 30 moles of ethylene oxide. Examples of commercially available nonionic detergents of the foregoing type are those presently commercially available under the trade name of Tergitol(copyright) (Union Carbide Ltd) such as Tergitol 15-S-12 which is described as being C11-C15 secondary alkanol condensed with 9 ethylene oxide units, or Tergitol 15-S-9 which is described as being C11-C15 secondary alkanol condensed with 12 ethylene oxide units per molecule.
Other suitable nonionic surfactant compositions include the polyethylene oxide condensates of one mole of alkyl phenol containing from about 8 to 18 carbon atoms in a straight-or branched chain alkyl group with about 5 to 30 moles of ethylene oxide. Specific examples of alkyl phenol ethoxylates include nonyl phenol condensed with about 9.5 moles of ethylene oxide per mole of nonyl phenol, dinonyl phenol condensed with about 12 moles of ethylene oxide per mole of phenol, dinonyl phenol condensed with about 15 moles of ethylene oxide per mole pf phenol and diisoctylphenol condensed with about 15 moles of ethylene oxide per mole of phenol. Commercially available nonionic surfactants of this type include those which are presently commercially available under the trade name of Igepal(copyright) (Rhone-Poulenc, Chemicals Ltd).
Also among the satisfactory nonionic surfactants which find use with the present inventive compositions are the water-soluble condensation products of a C8-C20 alkanol with a mixture of ethylene oxide and propylene oxide wherein the weight ratio of ethylene oxide to propylene oxide is from 2.5:1 to 4.1, preferably 2.89:1 to 3.3:1, with the total of the ethylene oxide and propylene oxide (including the terminal ethanol or proponol group) being from 60-85%, preferably 70 to 80%, by weight. Such surfactants include those which are presently commercially available under the trade name of Plurafac(copyright) (BASF plc). Further useful water-soluble condensation products of a C8-C20 alkanol with a mixture of ethylene oxide and/or propylene oxide include those which are presently marketed under the trade name Poly-Tergent SL (Olin UK Ltd) series of nonionic surfactants which are cited to comprise between 5 and 12 moles of oxyethylene per molecule.
Other suitable water-soluble nonionic detergents which are less preferred but which are nonetheless useful are those which are marketed under the trade name Pluronics(copyright) (BASF plc). The compounds are formed by condensing ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol The molecular weight of the hydrophobic portion of the molecule is of the order of 950 to 4,000 and preferably 200 to 2,500. The addition of polyoxyethylene radicals of the hydrophobic portion tends to increase the solubility of the molecule as a whole so as to make the surfactant water-soluble. The molecular weight of the block polymers varies from 1,000 to 15,000 and the polyethylene oxide content may comprise 20% to 80% by weight. Preferably, these surfactants are in liquid form and particularly satisfactory surfactants are available as those marketed as Pluronics(copyright) L62 and Pluronics L64.
Alkylmonoglyocosides and alkylpolyglycosides which find use in the present inventive compositions include known nonionic surfactants which are alkaline and electrolyte stable. Alkylmonoglycosides and alkylpolyglycosides are prepared generally by reacting a monosaccharide, or a compound hydrolyzable to a monosaccharide with an alcohol such as a fatty alcohol in an acid medium. Various glycoside and polyglycoside compounds including alkoxylated glycosides and processes for making them are disclosed in U.S. Pat. Nos. 2,974,134; 3,219,656; 3,598,865; 3,640,998; 3,707,535, 3,772,269; 3,839,318; 3,974,138; 4,223,129 and 4,528,106.
One exemplary group of such useful alkylpolyglycosides include those according to the formula:
R2Oxe2x80x94(CnH2nO)rxe2x80x94(Z)x
where Z is derived from glucose, R2 is a hydrophobic group selected from alkyl groups, alkylphenyl groups, hydroxyalkylphenyl groups as well as mixtures thereof, wherein the alkyl groups may be straight chained or branched, which contain from about 8 to about 18 carbon atoms, n is 2 or 3, r is an integer from 0 to 10, but is preferably 0, and x is a value from about 1 to 8, preferably from about 1.5 to 5. Preferably the alkylpolyglycosides are nonionic fatty alkylpolyglucosides which contain a straight chain or branched chain C8-C15 alkyl group, and have an average of from about 1 to S glucose units per fatty alkylpolyglucoside molecule. More preferably, the nonionic fatty alkylpolyglucosides which contain straight chain or branched C8-C15 alkyl group, and have an average of from about 1 to about 2 glucose units per fatty alkylpolyglucoside molecule.
A further exemplary group of alkyl glycoside surfactants suitable for use in the practice of this invention may be presented by formula I below:
ROxe2x80x94(R1O)yxe2x80x94(G)xZbxe2x80x83xe2x80x83I
wherein: R is a monovalent organic radical containing from about 6 to about 30, preferably from about 8 to 18 carbon atoms; R1 is a divalent hydrocarbon radical containing from about 2 to about 4 carbon atoms; y is a number which has an average value from about 0 to about 1 and is preferably 0, G is a moiety derived from a reducing saccharide containing 5 or 6 carbon atoms; and x is a number having an average value from about 1 to 5 (preferably from 1.1 to 2); Z is O2M1,
O(CH2), CO2M1, OSO3M1, or O(CH2)SO3M1; R2 is (CH2)CO2M1 or CHxe2x95x90CHCO2M1; (with the proviso that Z can be O2M1 only if Z is in place of a primary hydroxyl group in which the primary hydroxyl-bearing carbon atom, xe2x80x94CH2OH, is oxidized to form a
group) b is a number of from 0 to 3xc3x97+1 preferably an average of from 0.5 to 2 per glycosal group; p is 1 to 10, M1 is H+ or an organic or inorganic counterion, particularly cations such as, for example, an alkali metal cation, ammonium cation, monoethanolamine cation or calcium cation.
As defined in Formula 1 above, R is generally the residue of a fatty alcohol having from about 8 to 30 and preferably 8 to 18 carbon atoms. Examples of such alkylglycosides as described above include, for example APG(trademark)325 CS Glycoside(copyright) which is described as being a 50% C9-C11 alkyl polyglycoside, also commonly referred to as D-glucopyranoside, (commercially available from Henkel Ltd) and Glucopon(trademark) 625 CS which is described as being a 50% C10-C16 alkyl polyglycoside, also commonly referred to as a D-glucopyranoside, (available from Henkel Ltd).
The nonionic surfactant can be present either singly, or a mixture of two or more nonionic surfactant compounds as defined above. Preferably, the total amount of non-ionic/cationic surfactants is from 1% to 10%.
Solvents usable in the compositions of present invention may be selected from solvents known in the art, of which volatile silicones, n-paraffins, alcohols, glycol ethers, propylene glycol, dipropylene glycol, iso-paraffins and amino methyl propanol are particularly suitable. Preferably, the solvent is present in an amount of from 0% to 8%.
An important function of the solvents included in the inventive formulations is the removal of fat and grease deposits. In principle, any solvent capable of removal of such deposits, which meets environmental and safety requirements and which may stably be included in the inventive formulations without deleteriously affecting desirable properties of the compositions, may be included.
It is desirable that at least a portion of the abrasive particles in the compositions of the invention should be maintained in suspension, in order to obviate the need for excessive shaking or agitation of the composition by the consumer prior to use. To this end, the compositions of the invention preferably include a thickening agent. The thickening agent may be such as to provide the composition with a generally Newtonian viscosity. Alternatively, the composition may be provided with a structured rheology, such as a shear thinning rheology. It is, of course, essential that the composition is pourable. Generally, for compositions with Newtonian viscosity, the viscosity will be in the range of from 200 to 600 Cps (as measured using a Brookfield DV-III viscometer). Where the composition has a structed rheology, the measured viscosity may be considerably higher. Suitable thickeners and rheology modifiers include polysaccharides such as hydroxy celluloses, carboxy methyl celluloses, such inorganic thickening agents based on clays as are compatible with quaternary ammonium antibacterial agents and other thickening media known in the art and compatible with quaternary ammonium antibacterial agents. Preferably, the thickener is present in an amount of from 0.1% to 8%.
The compositions of the invention may further include optional ingredients such as fragrances, colouring agents, silicas, preservatives, pH regulants, freeze-thaw stabilisers, opacifiers, optical brighteners and the like.
Test for Antibacterial Effect
A saturated solution of sodium bicarbonate was prepared containing 2.0% BTC 2125M which is believed to be a myristyl dimethyl benzyl ammonium chloride. The amount of BTC present is expressed as weight percent active material. To this solution further solid sodium bicarbonate was added and the mixture left overnight. The solid sodium bicarbonate was removed by filtration and the filtered solution was assessed for antimicrobial efficacy using prEN 1276 (proposed standard protocol for assessing disinfectants used in food, industrial, domestic and institutional areas), against Pseudomonas aeruginosa and Staphylococcus aureus. A control solution comprising 2.0% BTC 2125M only was similarly assessed. The results are shown in Table 1 below:
From these results, it can be seen that when solid sodium bicarbonate is added to a saturated solution of sodium bicarbonate containing a quaternary ammonium antibacterial agent, left to equilibrate overnight and the solid filtered off, within the limits of the test, no drop in antimicrobial activity of the residual solution is seen. A drop in antimicrobial activity would be expected if a significant amount of the quaternary ammonium compound became adsorbed on or otherwise deactivated by the particles of sodium bicarbonate.
The antibacterial effect of the quaternary ammonium antibacterial agents given in Table 2 below was tested in accordance with the method of Sample 1, but using 1.5% w/v (of active material) of the quaternary ammonium antibacterial agent in both the saturated sodium bicarbonate solution and in the control solution. In each case, the ME value against both Ps. aeruginosa and S. aureus was greater than 5.0.
The following Examples illustrate the invention.