Process for producing a liquid detergent composition containing a liquid crystal phase

Abstract

To provide processes for making stable, structured, liquid detergent compositions, such as liquid laundry detergent compositions, having a high fraction of liquid crystalline phase.SOLUTION: A process for making a liquid laundry detergent composition comprises the steps of: a) providing an isotropic base mix and b) adding non-surfactant salt to the isotropic base mix, and a resultant liquid detergent composition further comprises 12-30 wt.% of a surfactant based on the weight of the liquid detergent composition.SELECTED DRAWING: None

Description

Technical Field

[0001] Process for producing a stable and structured liquid detergent composition, particularly a liquid laundry detergent composition, having a high liquid crystal phase fraction.

Background Art

[0002] Particularly for household and laundry detergent compositions, there are different preferences and needs among different consumers. After cleaning the surfaces and laundry within the home, all consumers desire that the home and laundry be clean and have a fresh smell. However, different consumers have different ideas about which fragrance is "fresh". In addition, there are different requirements for color. Furthermore, it is also desired to have various detergent compositions having specific types and concentrations of functional components. For example, the detergent composition may contain a specific soil removal polymer to improve the level of particulate and grease cleaning, or may contain fragrance microcapsules to make the fresh feeling last longer.

[0003] To simplify production, it is desirable to make such liquid compositions tailored to each consumer from a common basic mixture. Such a basic mixture contains components common to different formulation types. To make the final detergent composition, differentiating components and other components are added at desired concentrations to result in a detergent composition having the desired appearance and performance. To facilitate the mixing of such components into the basic mixture, a basic mixture having a low viscosity is desired.

[0004] To facilitate storage and transportation, it is desirable to formulate a basic mixture having a high concentration of surfactant and then dilute the basic mixture to achieve the surfactant concentration desired in the final product.

[0005] However, at high surfactant concentrations, a liquid crystal phase is typically formed. Unless the detergent composition is structured, such a liquid crystal phase precipitates into a phase rich in the liquid crystal phase. Therefore, to limit the amount of such liquid crystal phase in the base mixture and to avoid phase separation of the base mixture, the base mixture is typically formulated with a sufficient solvent or hydrotrope. However, the use of a solvent causes the base mixture to have a low flash point, and as a result, an explosion-proof process may be required. Furthermore, the resulting final detergent composition also contains a higher concentration of the solvent and requires a higher concentration of structuring agent to achieve the desired viscosity.

[0006] European Patent No. 1220886 relates to a lamellar phase liquid detergent composition containing a strong electrolyte at a low concentration.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] Thus, there remains a need for a process that can produce a differentiated liquid detergent composition from a common stable base mixture without requiring a high concentration of solvent. In addition, there remains a need for a liquid detergent composition that requires little or no external structuring agent to achieve the viscosity and structuring level desired by consumers.

Means for Solving the Problems

[0009] The present invention relates to a process for producing a detergent composition, comprising the step of preparing an isotropic base mixture, the base mixture containing more than 15% by weight of a surfactant and less than 1.2% by weight of a non-surfactant salt, and the step of adding a non-surfactant salt to the isotropic base mixture such that the resulting liquid detergent composition contains at least 15% of a liquid crystal phase.

[0010] The present invention further relates to a liquid detergent composition comprising 1% to 70% by weight of a surfactant and less than 10% by weight of an organic non-amino functional solvent, a hydrotrope, and mixtures thereof, the liquid detergent composition comprising at least 15% of a liquid crystal phase.

DETAILED DESCRIPTION OF THE INVENTION

[0011] By limiting the amount of non-surfactant salts in the base mixture, a base mixture with a limited amount of liquid crystal phase can be provided without the need for high concentrations of solvents or hydrotropes. As a result, a common, stable, and easily flowable base mixture can be provided that can be subsequently processed by adding components specific to certain types. Furthermore, a base mixture with a lower flash point can be formulated. As one of the finishing steps, non-surfactant salts are added to form the liquid crystal phase. The base mixture and the resulting final product contain lower concentrations of solvents and hydrotropes, so a larger amount of the liquid crystal phase is present in the final product, and less or even no structuring agent needs to be added to achieve the desired viscosity characteristics.

[0012] As used herein, "liquid laundry detergent composition" refers to any laundry treatment composition that includes a fluid capable of wetting and cleaning fabrics such as clothing in a household washing machine. The composition can suitably include solids or gases in finely divided forms, but the composition as a whole excludes product forms that are non-fluid as a whole, such as tablets or granules. Any solid additives are excluded from the liquid detergent composition, but if present, any foam is included and preferably has a density in the range of 0.9 grams to 1.3 grams, more specifically 1.00 grams to 1.10 grams per cubic centimeter.

[0013] As used herein, the term "external structuring system" refers to a selected compound or mixture of compounds that, independent of any structuring effect of the detergency surfactant in the composition, i.e., by something other than the detergency surfactant, provides either a yield stress or a low-shear viscosity sufficient to stabilize a liquid laundry detergent composition. "Internal structuring" means relying on the detergent surfactant that forms the major class of the laundry components to provide the required yield stress or low-shear viscosity.

[0014] All percentages, ratios, and proportions used herein are by weight of the composition, unless otherwise specified. All average values are calculated based on the "weight" of the composition or its components, unless otherwise clearly specified.

[0015] Base mixture: The base mixture contains more than 15% by weight of surfactant. Preferably, the base mixture contains 15% to 85% by weight, more preferably 20% to 75% by weight, and even more preferably 25% to 50% by weight of surfactant. In a preferred embodiment, the base mixture contains a surfactant selected from the group consisting of anionic surfactants, nonionic surfactants, and mixtures thereof.

[0016] Suitable anionic surfactants may be selected from the group consisting of alkyl sulfates, alkyl ethoxysulfates, alkyl sulfonates, alkylbenzene sulfonates, fatty acids and their salts, and mixtures thereof. However, essentially any anionic surfactant known in the art of detergent compositions, such as those disclosed in W.M. Linfield, Surfactant Science Series, Vol. 7, can be used. However, the base mixture preferably contains at least a sulfonate surfactant, such as linear alkylbenzene sulfonic acid, and the water-soluble salt form can also be used. The anionic surfactant is typically present at a concentration of 1.0% to 70% by weight, preferably 5.0% to 50% by weight, and more preferably 10% to 30% by weight of the base mixture.

[0017] Suitable anionic sulfonates or sulfonic acid surfactants for use in this specification include linear or branched C5-C20, more preferably C10-C16, more preferably C11-C13 alkylbenzene sulfonates, C5-C20 alkyl ester sulfonates, C6-C22 primary or secondary alkane sulfonates, C5-C20 sulfonated polycarboxylic acids, and any mixtures thereof in acid and salt forms, with C11-C13 alkylbenzene sulfonates being preferred. The above surfactants can have widely different 2-phenyl isomer contents.

[0018] Suitable anionic sulfates for use in the compositions of the present invention include primary and secondary alkyl sulfates having a linear or branched alkyl or alkenyl moiety having 9-22 carbon atoms or more preferably 12-18 carbon atoms. Β-branched alkyl sulfate surfactants, or mixtures of commercially available substances, in which the weight average branching degree (of the surfactant or mixture) is at least 50% are also useful.

[0019] Medium-chain branched alkyl sulfates or sulfonates are also suitable anionic surfactants for use in the compositions of the present invention. Preferred are C5-C22, preferably C10-C20 medium-chain branched alkyl primary sulfates. When using a mixture, the preferred average total number of carbon atoms in the alkyl moiety is preferably in the range of more than 14.5 to 17.5. Preferred mono-methyl-branched primary alkyl sulfates are selected from the group consisting of 3-methyl to 13-methyl pentadecanol sulfates, the corresponding hexadecanol sulfates, and mixtures thereof. Dimethyl derivatives, or other biodegradable alkyl sulfates having slight branching can also be used.

[0020] Other suitable anionic surfactants for use in this specification include aliphatic methyl ester sulfonates and / or alkyl ethoxysulfates (AES) and / or alkyl polyalkoxylated carboxylates (AEC). Mixtures of anionic surfactants can also be used (e.g., a mixture of alkylbenzene sulfonate and AES).

[0021] Anionic surfactants typically exist in the form of salts with alkanolamines or alkali metals (such as sodium and potassium).

[0022] The base mixture preferably includes fatty acids, fatty acid salts, and mixtures thereof. Preferably, the base mixture includes 1% to 10% by weight, more preferably 2% to 7% by weight, and most preferably 3% to 5% by weight of fatty acids, fatty acid salts, and mixtures thereof.

[0023] The base mixture preferably includes nonionic surfactants. Preferably, the base mixture includes up to 15% by weight, more preferably 1% to 15% by weight, and most preferably 5% to 12% by weight of nonionic surfactants.

[0024] Suitable nonionic surfactants include C12 - C18 alkyl ethoxylates (''AE'') containing so-called narrow peaks of alkyl ethoxylates, and C6 - C12 alkylphenol alkoxylates (especially ethoxylates and ethoxy / propoxy mixtures), block-type alkylene oxide condensates of C6 - C12 alkylphenols, alkylene oxide condensates of C8 - C22 alkanols, and ethylene oxide / propylene oxide block polymers (Pluronic, BASF Corp.), but are not limited thereto, and semi-polar nonionic substances (e.g., amine oxides and phosphine oxides) can be used in the compositions of the present invention. A wide disclosure of these types of surfactants can be found in U.S. Patent No. 3,929,678 (Laughlin et al., issued December 30, 1975).

[0025] Alkyl polysaccharides, such as those disclosed in U.S. Patent No. 4,565,647 (Llenado), are also nonionic surfactants useful in the compositions of the present invention.

[0026] Alkyl polyglucoside surfactants are also preferred.

[0027] In some embodiments, useful nonionic surfactants include those of the formula R1(OC2H4) n OH, wherein R1 is a C10-C16 alkyl group or a C8-C12 alkylphenyl group, and n is preferably from 3 to 80. In some embodiments, the nonionic surfactant may be a condensation product of 5 to 20 moles of ethylene oxide per mole of alcohol and a C12-C15 alcohol, for example, a condensation product of 6.5 moles of ethylene oxide per mole of alcohol and a C12-C13 alcohol.

[0028] Another preferred nonionic surfactant includes polyhydroxy fatty acid amides of the following formula.

[0029]

Chemical formula

[0030] The base mixture may include additional surfactants selected from the group consisting of amphoteric and / or zwitterionic surfactants, cationic surfactants, semi-polar surfactants, and mixtures thereof.

[0031] Suitable amphoteric or zwitterionic detergency surfactants include those known for use in hair care or other personal care cleansing. Non-limiting examples of suitable zwitterionic or amphoteric surfactants are described in U.S. Patent Nos. 5,104,646 (Bolich Jr. et al.) and 5,106,609 (Bolich Jr. et al.). Suitable amphoteric detergency surfactants include those widely described as derivatives of aliphatic secondary and tertiary amines, in which the aliphatic radical may be straight-chain or branched-chain, and one of the aliphatic substituents contains 8 to 18 carbon atoms and one contains an anionic group, such as a carboxy group, a sulfonic acid group, a sulfuric acid group, a phosphoric acid group, or a phosphonic acid group. Suitable amphoteric detergency surfactants for use in the present invention include, but are not limited to, cocoamphoacetate, cocoamphodiacetate, lauroamphoacetate, lauroamphodiacetate, and mixtures thereof.

[0032] Suitable zwitterionic detergency surfactants are well-known in the art and include those widely described as derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radical may be straight-chain or branched-chain, and one of the aliphatic substituents contains 8 to 18 carbon atoms and one contains an anionic group, such as a carboxy group, a sulfonic acid group, a sulfuric acid group, a phosphoric acid group, or a phosphonic acid group. Zwitterionic surfactants such as betaines are suitable for the basic mixture.

[0033] Suitable semi-polar surfactants include amine oxide surfactants. R(EO) x (PO) y (BO) zAmine oxide surfactants having the formula N(O)(CH2R’)2.qH2O (I) are particularly useful in the basic mixtures of the present invention. R is a relatively long-chain hydrocarbyl moiety which can be saturated or unsaturated, straight-chain or branched-chain, and can contain from 8 to 20, preferably from 10 to 16 carbon atoms, more preferably C12 - C16 primary alkyl. R’ is preferably a short-chain moiety selected from hydrogen, methyl and -CH2OH. When x + y + z is different from 0, EO is ethyleneoxy, PO is propyleneneoxy, and BO is butyleneoxy. The amine oxide surfactant is represented by C 12~14 alkyl dimethyl amine oxide.

[0034] Non-limiting examples of other anionic, zwitterionic, amphoteric, or any additional surfactants suitable for use in the compositions are described in McCutcheon’s, Emulsifiers and Detergents, 1989 Annual (M.C. Publishing Co.), and U.S. Patent Nos. 3,929,678, 2,658,072, 2,438,091, and 2,528,378.

[0035] For the purposes of the present invention, the surfactant-free salt does not contain amphiphilic molecules. Thus, the surfactant-free salt does not contain ions having a hydrophobic tail bonded to a charged group. Therefore, the surfactant-free salt does not lower the surface tension of the solution. Such a surfactant-free salt ionizes when dissolved in water and promotes the formation of a liquid crystal phase in the composition. Suitable surfactant-free salts may be selected from the group consisting of sodium carbonate, sodium hydrogen carbonate (sodium bicarbonate), magnesium chloride, ethylenediaminetetraacetate (EDTA), diethylenetriaminepentaacetate (DTPA), hydroxyethanediphosphonate (HEDP), sodium chloride, citrate, calcium chloride, sodium formate, diethylenetriaminepentamethylenephosphonate, and mixtures thereof. Preferred surfactant-free salts provide additional benefits to the composition, for example, as builders. For the purposes of the present invention, surfactant-free salts that provide a builder effect are first considered as surfactant-free salts. Examples of salts of ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethanediphosphonic acid (HEDP), citric acid, and diethylenetriaminepentamethylenephosphonic acid include metal salts such as sodium salts, calcium salts, and magnesium salts, with sodium salts being preferred.

[0036] In a preferred embodiment, the base mixture comprises less than 1.2% by weight, preferably from 0.1% to 1.2% by weight, more preferably from 0.2% to 0.9% by weight, and most preferably from 0.4% to 0.7% by weight of a surfactant-free salt. In a more preferred embodiment, the base mixture comprises less than 1.2% by weight, preferably from 0.1% to 1.2% by weight, more preferably from 0.2% to 0.9% by weight, and most preferably from 0.4% to 0.7% by weight of a surfactant-free salt selected from the group consisting of sodium carbonate, sodium hydrogen carbonate (sodium bicarbonate), magnesium chloride, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethanediphosphonic acid (HEDP), sodium citrate, sodium chloride, citric acid, calcium chloride, sodium formate, diethylenetriaminepentamethylenephosphonic acid, and mixtures thereof.

[0037] When a surfactant salt is added to the base mixture as a premix, the pre-alkalinity of the premix is preferably sufficiently low such that the change in pH of the base mixture after adding the premix to the base mixture is slight.

[0038] As a result of the low concentration of surfactant salt, the base mixed composition contains little or no liquid crystal phase. Preferably, the base mixture contains less than 15% by volume, preferably less than 10% by volume, more preferably less than 5% by volume, and most preferably less than 1% by volume of the liquid crystal phase.

[0039] Aqueous detergent compositions typically contain a significant amount of surfactant. Above the critical micelle concentration (CMC), the surfactant re-aligns to form micelles such as spherical, cylindrical (rod-shaped), and disc-shaped micelles. As the surfactant concentration increases, an aligned liquid crystal phase, such as a lamellar phase, hexagonal phase, cubic phase, or a combination thereof, forms. The lamellar phase consists of alternating bilayer surfactant and water layers. These layers are generally not flat but are folded to form sub-micrometer spherical onion-like structures called vesicles or liposomes. On the other hand, the hexagonal phase consists of long cylindrical micelles aligned in a hexagonal lattice. Generally, the microstructure of many aqueous detergent compositions consists of either spherical micelles, rod-shaped micelles, or a lamellar phase. The micelles can be spherical or rod-shaped. Formulations with spherical or rod-shaped micelles tend to have low viscosities and are more easily processed.

[0040] Methods for identifying liquid crystal phases are well known in the art and include microscopy methods such as conoscopic microscopy. For example, lamellar phase compositions are readily identified by their characteristic focal conic shapes and oily streak textures, while the hexagonal phase exhibits an angular fan-like texture. In contrast, the micellar phase is optically isotropic and has little effect on the turbidity of the detergent composition.

[0041] It should be understood, for example, that liquid crystal phases can be formed with various surfactant systems as described in U.S. Patent No. 5,952,286.

[0042] Methods for revealing the characteristics of the liquid crystal phase are well known in the art, and include microscopy, in particular crossed polarization microscopy. Micrographs generally show the liquid crystal microstructure and the closest packing of liquid crystal droplets (generally in the dimension range of about 2 micrometers). Another method for measuring the liquid crystal phase is to use a freeze fracture electron microscope.

[0043] The basic mixture is preferably isotropic. Thus, the basic mixture preferably has a turbidity of less than 5 NTU to less than 3000 NTU, preferably less than 1000 NTU, more preferably less than 500 NTU, and most preferably less than 100 NTU. Preferably, the basic mixture does not contain suspended substances.

[0044] Since the basic mixed composition contains little or no liquid crystal phase, the concentrations of the solvent and hydrotrope that need to be present in the basic mixture also decrease. Thus, the basic mixture preferably contains less than 4% by weight, more preferably less than 3.0% by weight, and most preferably less than 2.0% by weight of organic non-amino functional solvents, hydrotropes, and mixtures thereof. To avoid misunderstanding, a hydrotrope that is also a salt is considered a hydrotrope in the present invention because such a hydrotrope greatly affects the solubilization of the liquid crystal phase in the detergent composition. When the basic mixture contains less of the organic non-amino functional solvent, hydrotrope, and mixtures thereof, more liquid crystal phase is present in the final liquid detergent composition.

[0045] As used herein, "non-amino functional organic solvent" refers to any solvent that does not contain an amino functional group and further does not contain nitrogen. Examples of non-amino functional solvents include C1-C5 alkanols (such as methanol, ethanol and / or propanol and / or 1-ethoxypentanol, etc.), C2-C6 diols, C3-C8 alkylene glycols, C3-C8 alkylene glycol mono-lower alkyl ethers, glycol dialkyl ethers, low molecular weight polyethylene glycols, C3-C9 triols (such as glycerol, etc.), and mixtures thereof. More specifically, the non-amino functional solvent is liquid at ambient temperature and pressure (i.e., 21 °C and 0.1 MPa (1 atm)) and contains carbon, hydrogen and oxygen.

[0046] When used, an organic non-amino functional solvent is preferred. Such organic non-amino functional solvents include monohydric alcohols, dihydric alcohols, polyhydric alcohols, glycerol, glycols, polyalkylene glycols (such as polyethylene glycol, etc.), and mixtures thereof.

[0047] When used, extremely preferred are mixtures of organic non-amino functional solvents, in particular mixtures of lower aliphatic alcohols such as propanol, butanol, isopropanol, etc., and / or diols such as 1,2-propanediol or 1,3-propanediol; diethylene glycol, or mixtures thereof. Preferred is propanediol (in particular, 1,2-propanediol), or a mixture of propanediol and diethylene glycol. The preferred basic mixture contains less than 2.5% by weight, preferably less than 1.5% by weight, more preferably less than 1% by weight of methanol or ethanol.

[0048] High concentrations of volatile alcohols greatly affect the flammability of compositions, especially liquid compositions. Flammable substances can be classified by their closed cup flash point (CCFP) and boiling point using the following National Fire Protection Association (NFPA) classification. Class IA-CCFP is less than 23°C (73°F) and boiling point is less than 38°C (100°F). Class IB-CCFP is less than 23°C (73°F) and boiling point is greater than 38°C (100°F). Class IC-CCFP is greater than 23°C (73°F) but less than 38°C (100°F). Class II-CCFP is 38°C (100°F) or higher but less than 60°C (140°F). Class IIIA-CCFP is 60°C (140°F) or higher but less than 93°C (200°F). Class IIIB-CCFP is 93°C (200°F) or higher

[0049] Flammability is measured according to the Pensky-Martens closed cup flash point (CCFP) method described in ASTM D93.

[0050] Depending on the classification, the requirements for the safe handling and storage of the liquid detergent composition, including storage location and temperature control conditions, change. Therefore, the base mixture preferably has an NFPA classification of IC, preferably II, more preferably IIIA, and most preferably IIIB.

[0051] Suitable hydrotropes include anionic hydrotropes such as those disclosed in U.S. Patent No. 3,915,903, particularly sodium xylene sulfonate, potassium xylene sulfonate, and ammonium xylene sulfonate, sodium toluene sulfonate, potassium toluene sulfonate and ammonium toluene sulfonate, sodium cumene sulfonate, potassium cumene sulfonate and ammonium cumene sulfonate, and mixtures thereof.

[0052] To facilitate processing, the base mixture preferably has a 20s -1When measured at 20 °C, it has a viscosity of 0.010 - 2 Pa·s. Furthermore, since the basic mixture composition contains little or no liquid crystal phase or other suspended substances, the basic mixture has little tendency to phase separate. As a result, little or no structuring agent is required in the basic mixture. Therefore, the basic mixture preferably contains less than 2% by weight, more preferably less than 1% by weight of an external structuring agent. Even more preferably, the basic mixture contains no external structuring agent.

[0053] For stability improvement, especially when the basic mixture contains fatty acids, the basic mixture preferably has a pH of 6.5 - 13, more preferably 7 - 10, most preferably 8 - 9 when measured at 25 °C for a 10% by weight solution diluted with deionized water. Since it has a stable pH, the basic mixture preferably has a pre-alkalinity of 0.20 - 0.30 g NaOH / 100 g at pH 7.5.

[0054] The basic mixture preferably contains water. The water content is preferably 1% - 70% by weight, preferably 10% - 65% by weight, more preferably 30% - 55% by weight of the basic mixture.

[0055] The basic mixture or the subsequent liquid detergent composition may contain additional components such as those selected from the group consisting of adhesion aid polymers, organic builders and / or chelating agents, enzymes, enzyme stabilizers, cleaning polymers, and mixtures thereof.

[0056] Adhesion Aid Polymer: The basic mixture may contain from 0.1% to 7%, more preferably from 0.2% to 3% of an adhesion aid polymer. As used herein, "adhesion aid polymer" refers to any cationic polymer or mixture of cationic polymers that significantly increases the adhesion of fabric care beneficial agents to the fabric during washing. Suitable adhesion aid polymers can include cationic polysaccharides and / or copolymers. As used herein, "fabric care beneficial agent" refers to any substance that can provide a fabric care effect. Non-limiting examples of fabric care beneficial agents include silicone derivatives, oily sugar derivatives, dispersible polyolefins, polymer latexes, cationic surfactants, and combinations thereof. Preferably, the adhesion aid is a cationic or amphoteric polymer. The cationic charge density of the polymer is preferably in the range of 0.05 milliequivalents / g to 6 milliequivalents / g. The charge density is calculated by dividing the net number of positive charges per repeating unit by the molecular weight of the repeating unit. In one embodiment, the charge density varies between 0.1 milliequivalents / g and 3 milliequivalents / g. The positive charges can be present on the main chain or on the side chain of the polymer.

[0057] Organic builders and / or chelating agents: The basic mixture may contain 0.6% to 10% by weight, preferably 2% to 7% by weight, of one or more organic builders and / or chelating agents. Suitable organic builders and / or chelating agents include MEA citrate, citric acid, aminoalkylene poly(alkylenephosphonates), alkali metal ethane 1-hydroxybisphosphonates, and nitrilotrimethylene, phosphonates, diethylenetriaminepenta(methylenephosphonic acid) (DTPMP), ethylenediaminetetra(methylenephosphonic acid) (DDTMP), hexamethylenediaminetetra(methylenephosphonic acid), hydroxy-ethylene 1,1-diphosphonic acid (HEDP), hydroxyethanedimethylenephosphonic acid, ethylenediaminedisuccinic acid (EDDS), ethylenediaminetetraacetic acid (EDTA), hydroxyethylethylenediaminetriacetate (HEDTA), nitrilotriacetate (NTA), methylglycinediacetate (MGDA),iminodisuccinate (IDS), hydroxyethyliminodisuccinate (HIDS), hydroxyethyliminodiacetate (HEIDA), glycinediacetate (GLDA), diethylenetriaminepentaacetate (DTPA), catecholsulfonate (such as Tiron™), and mixtures thereof.

[0058] Enzymes: Suitable enzymes provide cleaning performance and / or fabric care effects. Examples of suitable enzymes include, but are not limited to, hemicellulase, peroxidase, protease, cellulase, xylanase, lipase, phospholipase, esterase, cutinase, pectinase, keratinase, reductase, oxidase, phenol oxidase, lipoxygenase, ligninase, pullulanase, tannase, pentosanase, malanases, β-glucanase, arabinosidase, hyaluronidase, chondroitinase, laccase, and known amylases, or combinations thereof. Preferred enzyme combinations include a cocktail of conventional cleaning enzymes such as protease, lipase, cutinase and / or cellulase together with amylase. Cleaning enzymes are described in more detail in U.S. Patent No. 6,579,839.

[0059] Enzyme stabilizers: Enzymes can be stabilized using any known stabilizer system such as calcium and / or magnesium compounds, boron compounds and substituted boric acids, aromatic borate esters, peptides and peptide derivatives, polyols, low molecular weight carboxylates, relatively hydrophobic organic compounds [e.g., certain esters, dialkyl glycol ethers, alcohols, or alcohol alkoxylates], alkyl ether carboxylates in addition to a calcium ion source, benzamidine hypochlorite, lower aliphatic alcohols and carboxylic acids, N,N-bis(carboxymethyl)serine salts; (meth)acrylic acid-(meth)acrylic acid ester copolymers and PEG; lignin compounds, polyamide oligomers, glycolic acid or its salts; polyhexamethylene biguanide or N,N-bis-3-amino-propyl-dodecylamine or salts; and mixtures thereof.

[0060] Washing polymer: Suitable washing polymers are provided for washing a wide variety of soils on surfaces and fabrics and / or suspending soils. Any suitable washing polymer can be used. Useful washing polymers are described in U.S. Patent Application Publication No. 2009 / 0124528 (A1). Non-limiting examples of types of useful washing polymers include amphiphilic alkoxylated grease washing polymers, mud soil washing polymers, soil removal polymers, and soil suspending polymers.

[0061] Process for manufacturing a liquid detergent composition In the process of the present invention, a non-surfactant salt is added to the base mixture such that the resulting liquid detergent composition contains at least 15% liquid crystal phase. The liquid crystal phase is desired in the final detergent composition because its presence typically means that little or no external structuring agent is required to achieve the desired viscosity of the final product.

[0062] The concentration at which the surfactant forms a liquid crystal phase is reduced by the addition of a suitable non-surfactant salt. Liquid crystal dispersions, particularly lamellar dispersions, can have a high zero-shear viscosity (due to the close packing of the liquid crystal droplets that are the components), but these solutions are very shear-thinning and thus different from spherical or rod-like micelles. Due to the different densities, the liquid crystal phase has a tendency to induce phase separation, clearly resulting in a phase rich in liquid crystal and a phase with a low liquid crystal content. Thus, the liquid crystal phase is typically not desirable in the base mixture that can be stored for a long time before being processed into the final detergent composition.

[0063] Preferably, the non-surfactant salt is added until the liquid detergent composition contains 15% - 85%, preferably 5% - 70%, more preferably 10% - 60% liquid crystal phase. The non-surfactant salt is typically added to result in a concentration of at least 1.5 wt%, preferably 1.5 wt% - 10 wt%, more preferably 2.5 wt% - 7 wt%, most preferably 3 wt% - 5 wt% non-surfactant salt in the liquid detergent composition.

[0064] Suitable non-surfactant salts added to the base mixture to form the liquid crystal phase may be selected from the group consisting of sodium carbonate, sodium bicarbonate (sodium hydrogen carbonate), magnesium chloride, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethanediphosphonic acid (HEDP), sodium citrate, sodium chloride, citric acid, calcium chloride, sodium formate, diethylenetriaminepentamethylenephosphonic acid, and mixtures thereof.

[0065] In a preferred embodiment, the non-surfactant salt selected from the group consisting of sodium carbonate, sodium bicarbonate (sodium hydrogen carbonate), magnesium chloride, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethanediphosphonic acid (HEDP), sodium citrate, sodium chloride, citric acid, calcium chloride, sodium formate, diethylenetriaminepentamethylenephosphonic acid, and mixtures thereof is added to the base mixture at a concentration of 0.1 wt% to 10 wt%, more preferably 0.8 wt% to 7 wt%, and most preferably 1.6 wt% to 3.5 wt% of the resulting liquid detergent.

[0066] In a more preferred embodiment, the non-surfactant salt selected from the group consisting of sodium citrate, sodium chloride, citric acid, calcium chloride, sodium formate, sodium carbonate, sodium bicarbonate (sodium hydrogen carbonate), magnesium chloride, and mixtures thereof is added to the base mixture at a concentration of 0.1 wt% to 10 wt%, more preferably 0.8 wt% to 7 wt%, and most preferably 1.6 wt% to 3.5 wt% of the resulting liquid detergent.

[0067] The non-surfactant salt may be added as part of a salt premix. Such a salt premix typically does not contain a surfactant. Suitable salt premixes may include non-surfactant salts selected from the group consisting of sodium carbonate, sodium bicarbonate (baking soda), magnesium chloride, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), hydroxyethanediphosphonic acid (HEDP), sodium citrate, sodium chloride, citric acid, calcium chloride, sodium formate, diethylenetriaminepentamethylenephosphonic acid, and mixtures thereof.

[0068] The basic mixture is typically more concentrated than the desired final liquid detergent composition. Therefore, water is typically added so that the desired concentration of the active ingredient is achieved. Preferably, typically enough water is added to result in a liquid laundry detergent composition having a surfactant concentration of 5% to 40% by weight, preferably 12% to 30% by weight, in the final product.

[0069] The non-surfactant salt can be used to structure or increase the viscosity of a liquid detergent composition containing an external structuring agent, because such non-surfactant salts increase the amount of the liquid crystal phase present in the liquid detergent composition.

[0070] Thus, the liquid detergent composition may a) preparing a liquid detergent composition containing more than 15% of the liquid crystal phase; and b) adding an external structuring agent.

[0071] Preferably, a liquid detergent composition is provided by the basic mixture used in the process of the present invention, wherein the liquid crystal phase is formed by the addition of a non-surfactant salt. Since the liquid crystal phase is generally neutral in charge, preferred external structuring agents rely on charge-charge interactions to provide a structuring effect. Thus, particularly preferred external structuring agents are non-polymeric crystalline hydroxyl-functional structuring agents such as hydrogenated castor oil, microfibrillar cellulose, uncharged hydroxyethyl cellulose, uncharged hydrophobically modified hydroxyethyl cellulose, hydrophobically modified ethoxylated urethane, hydrophobically modified nonionic polyol, and those selected from the group consisting of mixtures thereof, etc., which are non-charged external structuring agents.

[0072] Depending on the desired cleaning or surface care effect desired, auxiliary components may be added to the liquid detergent composition. In a liquid laundry detergent composition, suitable auxiliary components may be selected from the group consisting of cationic surfactants, amphoteric and / or zwitterionic surfactants, enzymes, enzyme stabilizers, amphiphilic alkoxylated grease cleaning polymers, soil cleaning polymers, soil removal polymers, soil suspension polymers, bleaching systems, optical brighteners, hue dyes, particulate materials, fragrances and other malodor control agents, hydrotropes, antifoaming agents, fabric care beneficial agents, pH adjusters, anti-migration agents, preservatives, direct dyes for nonwovens, and mixtures thereof.

[0073] In a preferred embodiment, an external structuring agent is added to the liquid detergent composition and any other suspended substances that may be added to structure the resulting liquid crystal phase. The external structuring agent is preferably added at a concentration of 0.05% to 2% by weight, preferably 0.07% to 1% by weight, more preferably 0.1% to 0.38% by weight, and most preferably 0.15% to 0.3% by weight of the liquid detergent composition. The external structuring system is preferably selected from the group consisting of the following i and / or ii: i. non-polymeric crystalline hydroxy-functional structuring agents, and / or ii. polymeric structuring agents

[0074] Such external structuring systems impart sufficient yield stress or low shear viscosity to stabilize a fluid liquid laundry detergent composition, separately from or externally to any structuring effect of the detergent surfactant in the composition. Preferably, these impart to the fluid laundry detergent composition, at 1 s -1 , a high shear viscosity of 1 to 6500 cps at 20 °C and greater than 60 cps at 100 / s, and a viscosity of greater than 5000 cps at low shear (0.05 s -1 , 20 °C).

[0075] Suitable non-polymeric crystalline hydroxyl-functional structuring agents are known in the art and generally include crystallizable glycerides that can be pre-emulsified to assist in their dispersion in the final liquid detergent composition. Non-limiting examples of such pre-emulsified external structuring systems include (a) a crystallizable glyceride, (b) an anionic surfactant, (c) water, and optionally a non-amino-functional organic solvent. Each of these components will be discussed in detail below. Preferred non-polymeric crystalline hydroxy-functional structuring agents include crystallizable glycerides, preferably hydrogenated castor oil, i.e., "HCO".

[0076] Suitable polymeric structuring agents include naturally derived and / or synthetic polymeric structuring agents.

[0077] Examples of naturally derived polymeric structuring materials used in the present invention include microfibrillar cellulose, hydroxyethyl cellulose, hydrophobically modified hydroxyethyl cellulose, carboxymethyl cellulose, polysaccharide derivatives, and mixtures thereof. Non-limiting examples of microfibrillar cellulose are described in International Publication No. WO 2009 / 101545 (A1). Suitable polysaccharide derivatives include pectin, alginate, arabinogalactan (gum arabic), carrageenan, gellan gum, xanthan gum, guar gum, and mixtures thereof.

[0078] Examples of synthetic polymer structuring agents used in the present invention include polycarboxylates, polyacrylates, hydrophobically modified ethoxylated urethanes, hydrophobically modified nonionic polyols, and mixtures thereof.

[0079] Preferably, the polycarboxylate polymer is a polyacrylate, a polymethacrylate, or a mixture thereof. In another preferred embodiment, the polyacrylate is a copolymer of an unsaturated mono- or di-carbonic acid and a C1-C30 alkyl ester of (meth)acrylic acid. Such copolymers are available from Noveon Inc under the trade name Carbopol Aqua 30.

[0080] The surfactant-free salt increases the size of the liquid crystal phase and thus increases the viscosity of the liquid detergent composition. Therefore, even in the absence of an external structuring agent, structuring can be achieved using the surfactant-free salt, i.e., the viscosity of the liquid detergent composition can be increased. Further, when the surfactant-free salt is added at a concentration such that the liquid detergent composition contains a liquid crystal phase, particularly a lamellar phase, at a concentration of 15% to 85%, preferably 5% to 70%, more preferably 10% to 60%, the surfactant-free salt acts as a viscosity modifier and / or a structuring agent.

[0081] In a preferred embodiment, the different components are added to the base mixture in a continuous process. In a preferred continuous process, the base mixture is pumped through a pipe of suitable dimensions, and the different components are added at various inlets arranged along the pipe. Preferably, there is a mixing device after the last component inlet. More preferably, and to improve mixing, the mixing device is arranged at various positions along the pipe. Suitable mixing devices may include static and dynamic mixer devices. Examples of dynamic mixer devices are homogenizers, rotor-stators, and high-shear mixers. The mixing device can be a plurality of mixing devices arranged in series or in parallel to provide the required energy dissipation rate.

[0082] The process of the present invention results in a liquid detergent composition having a greater amount of liquid crystal phase, which composition is self-structuring or can be structured using a small amount of external structuring agent.

[0083] Such a liquid detergent composition preferably contains 1% to 70% by weight of a surfactant, less than 10% by weight of an organic non-amino functional solvent, a hydrotrope, and mixtures thereof, and contains at least 15% of a liquid crystal phase when measured using the method disclosed herein. In a more preferred embodiment, the liquid detergent composition contains 15% to 85%, preferably 5% to 70%, more preferably 10% to 60% of a liquid crystal phase. In a preferred embodiment, the liquid detergent composition contains 2% to 50% by weight, more preferably 5% to 40% by weight, most preferably 12% to 30% by weight of a surfactant.

[0084] The liquid detergent composition preferably contains less than 2.5% by weight, preferably less than 2% by weight, more preferably less than 1.2% by weight of an organic non-amino functional solvent, a hydrotrope, and mixtures of a solvent, a hydrotrope, and mixtures thereof.

[0085] In a more preferred embodiment, the liquid detergent composition contains 1% to 10% by weight of a fatty acid and has a pH of 6.5 to 13 when measured at 25 °C for a 10% by weight solution diluted with deionized water.

[0086] The liquid detergent composition may preferably contain an external structuring agent at a concentration of 0.05% to 2% by weight, more preferably 0.07% to 1% by weight, even more preferably 0.1% to 0.38% by weight of the liquid detergent composition.

[0087] Method: A) Method for evaluating the phase stability of a fluid laundry detergent composition: The phase stability of the composition is evaluated by placing 300 mL of the composition in a glass jar at 25 °C for up to 21 days. Within the above period, (i) if it does not separate into two or more layers, or (ii) if it separates into multiple layers but there is a major layer containing at least 90% by volume, preferably 95% by volume, more preferably 99% by volume of the composition, the composition is stable against phase separation.

[0088] B) Method for measuring viscosity: Viscosity is measured using an AR550 rheometer from TA Instruments with a flat steel spindle at a diameter of 40 mm and a gap size of 500 μm. High shear viscosity at 100 s -1 and low shear viscosity at 0.05 s -1 can be obtained from a logarithmic shear rate sweep at 0.05 s -1 to 1200 s -1 for 3 minutes at 21°C.

[0089] C) Turbidity (NTU): Turbidity (measured in NTU: Nephelometric Turbidity Units) is measured using a Hach 2100P turbidimeter calibrated according to the procedure provided by the manufacturer. Fill a sample vial with 15 mL of a representative sample according to the instruction manual, cap it, and wash it. If necessary, degas the sample to remove any bubbles by applying a vacuum or using an ultrasonic bath (see the instruction manual for the procedure). Turbidity is measured using automatic range selection.

[0090] D) Ratio of liquid crystal phase: Prepare a product that does not contain an external structuring agent and does not contain fine particles or other solids that do not dissolve in the product. Next, store the product sample in a graduated centrifuge tube at 5°C for at least 1 day, and then centrifuge it at 4400 rpm for 1 hour. After centrifugation, measure the % of the liquid crystal phase as the height of the liquid crystal phase measured with a ruler relative to the total height of the centrifuged sample.

[0091] E) Method for measuring pH: pH is measured at 25°C using a Santarius PT-10P pH meter with a gel-filled probe (e.g., Toledo probe, part number 52 000 100) calibrated according to the instruction manual.

Example

[0092] Base mixture 1 used in the process of the present invention was prepared by simply mixing. The resulting base mixture did not contain a liquid crystal phase and was isotropic.

[0093] The basic mixture 2 was prepared in the same manner, but included 1.8 wt% of HEDP. Since HEDP is acidic, 0.6 wt% of additional sodium hydroxide was added to reach the target pH. With the addition of HEDP, a turbid basic mixture containing 15% liquid crystal phase was obtained. As can be seen from the basic mixture 3, 2.3 wt% of additional ethanol was necessary to disperse the liquid crystal phase of the basic mixture 2 and obtain a stable isotropic basic mixture.

[0094] Similarly, when the basic mixture contained 1.5 wt% of citric acid, 2.1 wt% of additional ethanol was necessary to disperse the liquid crystal phase and obtain a stable isotropic basic mixture (see basic mixtures 4 and 5).

[0095] When the basic mixture contained 1.0 wt% of sodium carbonate, 2.3 wt% of additional ethanol was necessary to disperse the liquid crystal phase and obtain a stable isotropic basic mixture (see basic mixtures 6 and 7).

[0096]

Table 1

[0097] As can be seen from the above data, when the basic mixture contains more than 15 wt% of surfactant and less than 1.2 wt% of non-surfactant salt, a stable and transparent basic mixture is formed. Increasing the amount of non-surfactant salt results in the formation of a liquid crystal phase, and phase separation occurs if the basic mixture is not kept constantly stirred (see basic mixtures 2, 4, and 6). To provide a stable and transparent basic mixture, ethanol must be added to reduce the amount of liquid crystal phase to a negligible level (less than 2 wt%, see basic mixtures 3, 5, and 7).

[0098] The basic mixture 8 (used in the process of the present invention) and the basic mixture 9 (used in the comparative process) were prepared by simply mixing.

[0099] The base mixture 8 included a total of 2.3 wt% of a hydrotrope (sodium cumenesulfonate) and an organic non-amino functional solvent (ethanol) for the purpose of both isotropy and stability. In contrast, for the purpose of obtaining a stable and isotropic base, the base mixture 9 included a total of 4.1 wt% of a hydrotrope (sodium cumenesulfonate) and an organic non-amino functional solvent (ethanol).

[0100]

Table 2

[0101] The base mixture 8 and the base mixture 9 (for comparison) were processed and the final products 1 and 2 were obtained respectively by adding the following components.

[0102]

Table 3

[0103]

Table 4

[0104] Since the base mixture 8 contained less hydrotrope, significantly more liquid crystal phases were present in the final product 1 than in the final product 2. As a result, very little external structuring agent was required to obtain a final product with the desired structuring and viscosity characteristics.

[0105] The base mixture 10 (used in the process of the present invention) and the base mixture 11 (used in the comparative process) were simply mixed and prepared.

[0106] The base mixture 10 included a total of 1.73 wt% of a hydrotrope (sodium cumenesulfonate) and an organic non-amino functional solvent (ethanol) for the purpose of both isotropism and stability. In contrast, for the purpose of obtaining a stable and isotropic base, the base mixture 9 included a total of 3.47 wt% of a hydrotrope (sodium cumenesulfonate) and an organic non-amino functional solvent (ethanol).

[0107]

Table 5

[0108] The base mixture 10 and the base mixture 11 (comparison) were processed and the following components were added to obtain the final product 3, and further the comparative final products 4 and 5, respectively.

[0109]

Table 6

[0110]

Table 7

[0111] Again, since the base mixture 10 contained less hydrotrope, significantly more liquid crystal phases were present in the final products 3 and 4 than in the final product 5. As a result, very little external structuring agent was required to obtain the final product with the desired structuring and viscosity characteristics.

[0112] The dimensions and values disclosed herein should not be understood to be strictly limited to the exact numerical values recited. Rather, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range around that value. For example, a dimension disclosed as "40 mm" is intended to mean "about 40 mm".

Claims

1. A process for manufacturing a liquid detergent composition, comprising: a) A step of preparing an isotropic base mixture, wherein the isotropic base mixture comprises: i. A surfactant in an amount of more than 15% by weight based on the weight of the isotropic base mixture, the surfactant being an anionic surfactant selected from the group consisting of alkyl ethoxysulfates, alkylbenzene sulfonates, and mixtures thereof (excluding fatty acids, fatty acid salts, and mixtures thereof); ii. A non-surfactant salt in an amount of 0.1 - 1.2% by weight based on the weight of the isotropic base mixture, the non-surfactant salt being selected from the group consisting of salts of hydroxyethane diphosphonic acid (HEDP), salts of diethylenetriamine pentamethylene phosphonic acid, and mixtures thereof; iii. A component selected from fatty acids, fatty acid salts, and mixtures thereof in an amount of 1 - 7% by weight based on the weight of the isotropic base mixture; iv. A hydrotrope in an amount of less than 4% by weight based on the weight of the isotropic base mixture, the hydrotrope being selected from the group consisting of sodium xylene sulfonate, potassium xylene sulfonate, ammonium xylene sulfonate, sodium toluene sulfonate, potassium toluene sulfonate, ammonium toluene sulfonate, sodium cumene sulfonate, potassium cumene sulfonate, ammonium cumene sulfonate, and mixtures thereof, and the isotropic base mixture contains 0% by weight or less than 2% by weight of an external structuring agent based on the weight of the isotropic base mixture; b) A step of adding a non-surfactant salt selected from the group consisting of salts of hydroxyethane diphosphonic acid (HEDP), salts of diethylenetriamine pentamethylene phosphonic acid, and mixtures thereof to the isotropic base mixture, wherein the liquid detergent composition obtained by this addition step contains at least 15% by volume of a liquid crystal phase; and The resulting liquid detergent composition contains 12 - 30% by weight of a surfactant based on the weight of the liquid detergent composition.

2. The process according to claim 1, wherein the non-surfactant salt added to the isotropic base mixture in step (b) is added so as to provide a concentration of at least 1.5% by weight of the non-surfactant salt in the liquid detergent composition.

3. The process according to claim 1 or 2, wherein the isotropic base mixture in step a) further comprises a nonionic surfactant.

4. The process according to any one of claims 1 to 3, wherein the isotropic base mixture comprises less than 15% by volume of a liquid crystal phase.

5. c) adding the external structuring agent selected from the group consisting of non-polymeric crystalline hydroxyl-functional structuring agents, microfibrillar cellulose, uncharged hydroxyethyl cellulose, uncharged hydrophobically modified hydroxyethyl cellulose, hydrophobically modified ethoxylated urethane, hydrophobically modified nonionic polyol, and mixtures thereof The process according to any one of claims 1 to 4, further comprising.

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