Method for crosslinking polysaccharides in a concentrated aqueous-organic medium and detergent formulations comprising the same

Abstract

The present invention relates to a novel process for crosslinking polysaccharides of natural origin in aqueous-organic media and detergent formulations comprising the same. The process of the present invention produces gels of natural origin polymers more concentrated or free of added water and in powder form.

Description

Technical Field

[0001] This invention relates to household and industrial detergents. More particularly, this invention relates to novel methods for synthesizing naturally derived thickeners for use in such formulations. Background Technology

[0002] Existing industrial or household detergent formulations are alkaline or acidic.

[0003] - Alkaline detergent formulations are commonly used to remove oil stains from solid surfaces.

[0004] - Acidic detergent formulations are used not only to remove grease but also to degrease surfaces, especially those of equipment in the agri-food industry, or those of household appliances such as dishwashers and coffee machines. Furthermore, they are used to remove concrete or cement residue before any painting, and to clean grease-stained concrete surfaces. They should not produce excessive foam during cleaning operations, and they must possess good foaming and detergent properties.

[0005] Detergent formulations for industrial or household use are in the form of powders, concentrates, or liquids such as emulsions, and are used directly or diluted in a suitable solvent, depending on the application. In liquid form, particularly in emulsions, they include rheology modifiers for the polar phase. Polymers that modify the rheology of the polar phase particularly include anionic or cationic, amphiphilic, linear or branched, crosslinked or non-crosslinked polyelectrolytes. Once introduced into the polar phase, these polymers possess the property of unfolding in the polar phase under the electrostatic repulsion caused by the presence of negative and / or positive charges on the linear or branched, crosslinked or non-crosslinked polymer backbone. Rheology modifiers simultaneously provide an increase in the viscosity of the polar phase and impart a certain consistency and stability to the detergent or cleaning composition to be thickened.

[0006] Despite ample commercial supply, novel thickeners for the polar phase remain needed in detergent formulations for industrial or household use because the polymers currently used are primarily petrochemically derived, while user industries are keen on eco-design processes. Therefore, there is a need to develop alternative thickeners that, while possessing comparable properties, offer improved environmental characteristics due to their origin or the source of their precursors, or due to their biodegradability. The use of polysaccharides appears to be an acceptable alternative, as they have been used industrially for many years as texture or rheology modifiers in the preparation of pharmaceuticals, cosmetics, or food products.

[0007] Based on their chemical composition, they can be used as gelling agents or thickeners. A "thickener" is understood to be a chemical compound that increases the viscosity of the medium to which it is introduced. A "gelling agent" is understood to be a compound that transforms a liquid medium into a non-flowing, structured state by forming a three-dimensional network within the liquid; gels are considered an intermediate state between liquid and solid.

[0008] Polysaccharides are polymers of saccharides, or more commonly, polymers of sugars. According to the International Union of Pure and Applied Chemistry (IUPAC), the term sugar refers to monosaccharides, monosaccharide compounds themselves, and their derivatives, obtained through the reduction of a carbonyl group, the oxidation of one or more hydroxyl functional groups, or the substitution of one or more hydroxyl functional groups with hydrogen atoms or amine, phosphate, or sulfate functional groups.

[0009] The polysaccharides most commonly used in the aforementioned industries are polymers of monomer units containing monosaccharides such as glucose, galactose, mannose, xylose, and arabinose, or monomer units of monosaccharide derivatives in which the hydroxyl functional group of the terminal carbon has been oxidized to a carboxyl functional group.

[0010] Polysaccharides composed entirely of monosaccharides (polymonosaccharides) specifically include: - Starch and starch derivatives are glucose homopolymers with alpha-1,4 glycosidic linkages: distinguished by linear homopolymers called amylose (approximately 20% of starch, consisting only of alpha-1,4 linkages) and branched homopolymers called amylopectin (approximately 80% of starch, consisting of both alpha-1,4 and alpha-1,6 glycosidic linkages). Starch is obtained from plants such as wheat, corn, or potatoes; - Cellulose, which is a homopolymer of glucose with β-1,4 glycosidic bonds: Cellulose is extracted from wood and is mainly used in the paper industry to produce pulp; - Hemicellulose is a polymer of various sugars such as glucose, mannose, galactose, xylose, arabinose, and rhamnose, with xylose usually being the main component. Hemicellulose sometimes also contains uronic acid.

[0011] Polysaccharides composed of monosaccharide derivatives include: - Sulfated galactan, which is a polymer of galactose that may have sulfate ester side groups, such as algal polysaccharides or agar; - uronans are polymers of uronic acids, such as alginate and pectin; - Monosaccharide heteropolymers, including galactomannans such as guar gum, tara gum, locust bean gum, and fenugreek gum, and glucomannoglycans such as konjac gum; and - Xyloglycans, such as tamarind gum. - Polymers of monosaccharides and uronic acids; these polymers are particularly found in sap exudates, such as gum arabic and karaya gum; they are also produced by microorganisms, such as xanthan gum and gellan gum. - Glucosaminoglycans: These are polysaccharides formed from glucose by replacing its C-2 hydroxyl group with an amine functional group (called 2-amino-2-deoxy-D-glucose or glucosamine); the amine functional group can be acetylated. This class of polysaccharides includes chitosan, which is formed entirely of glucosamine units, chitin, which has acetylated amine functional groups, and hyaluronan (whose repeating unit is a dimer of glucosamine and glucuronic acid).

[0012] Chemical modification of polysaccharides is one way to improve their initial properties and provide new characteristics. This is achieved through chemical functionalization by grafting relatively high molecular weight new chemical groups, or through crosslinking, which involves combining polysaccharide chains with each other using at least a bifunctional crosslinking agent called a crosslinker. In both cases, the functional groups of the starting polysaccharide involved retain hydroxyl (monosaccharides), amino (glucosamine derivatives), or carboxyl (uronic acid derivatives).

[0013] However, such functionalization is often carried out using environmentally unfriendly reactants or according to procedures that only partially comply with the twelve principles of green chemistry, such as the use of organic solvents. Furthermore, the resulting products currently cannot compete with petrochemically derived thickening polymers in terms of thickening or gelling properties.

[0014] Among the crosslinking agents commonly used for crosslinking natural polysaccharides, only those belonging to the polyphosphate derivative family, such as sodium trimetaphosphate (STMP) or sodium tripolyphosphate (STPP), are environmentally advantageous. STMP is a non-toxic compound to humans and is commonly used in the food and pharmaceutical industries; it is synthesized by the high-temperature dehydration of sodium polyphosphate; it is partially soluble in cold water, very poorly soluble in hot water, and insoluble in methanol, diethyl ether, n-octanol, and acetone. Polysaccharide crosslinking using STMP, as described in patents or academic literature, is carried out for several hours in an aqueous medium under alkaline pH conditions at temperatures ranging from 20°C to 50°C.

[0015] However, the crosslinking methods used to date yield highly diluted crosslinked natural polymer gels, i.e., containing approximately 3% by weight of the crosslinked polymer. Such dilution makes it impossible to prepare crosslinked natural polysaccharides in powder form on an industrial scale. Furthermore, the commercialization of such hydrogels (i.e., solutions containing water and 3% or 5% by weight of crosslinked polysaccharides) incurs unacceptable logistical costs due to the need to transport large quantities of water. Therefore, there is a need to develop crosslinking methods that produce more concentrated or water-free, naturally derived polymer gels in powder form. Summary of the Invention

[0016] Therefore, according to the first aspect, one subject of the present invention is a method for preparing at least one cross-linked polysaccharide, comprising the following steps: - Step a), preparing a water-polar solvent mixture, wherein the polar solvent is selected from aliphatic alcohols containing 1 to 4 carbon atoms, ketones containing 3 to 5 carbon atoms, and polyols containing 2 or 3 hydroxyl groups and 2 to 6 carbon atoms, wherein the preparation is carried out by mixing water and the polar solvent in a weight ratio of the polar solvent to water greater than or equal to 0.4 and less than or equal to 19.0; - Step b) Dispersing at least one polysaccharide in the water-polar solvent mixture prepared in step a) to obtain a reaction medium comprising, by weight 10% and less than or equal to 55% of a polysaccharide, selected from the group consisting of: xanthan gum, xanthan gum with hydrocarbons branched with 2 to 22 carbon atoms, more particularly xanthan gum esterified with dodecanoate, guar gum and konjac gum, carrageenan, more particularly kappa-carrageenan and iota-carrageenan, and mixtures of two or more of the polysaccharides from the group. - Step c), adjusting the pH of the reaction medium prepared in step b) to a value greater than or equal to 8.0 and less than or equal to 13.0, more particularly greater than or equal to 8.5 and less than or equal to 12.5 by adding alkali; - Step d), crosslinking the at least one polysaccharide by adding a phosphate crosslinking agent selected from sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) to the alkaline reaction medium obtained at the end of step c), to obtain an alkaline dispersion containing the crosslinked polysaccharide; - Step e), adjust the pH of the alkaline dispersion obtained at the end of step d) to a value less than or equal to 7.0 to obtain a non-alkaline dispersion of the cross-linked polysaccharide; - Step f), filtering the non-alkaline dispersion obtained at the end of step e) to recover the at least one intended cross-linked polysaccharide therefrom, optionally followed by: - Drying step g) to remove trace amounts of residual solvent. - or step h), atomize the at least one cross-linked polysaccharide obtained in step f) to obtain a powder therefrom.

[0017] According to a specific aspect of the method defined above, steps a) and b) are simultaneous and constitute a single step A), namely, the preparation of the reaction medium by mixing water, a polar solvent selected from aliphatic alcohols containing 1 to 4 carbon atoms, ketones containing 3 to 5 carbon atoms, and polyols containing 2 or 3 hydroxyl groups and 2 to 6 carbon atoms, and a polysaccharide, in proportions such that: - The weight percentage of the at least one polysaccharide is greater than 10% by weight and less than or equal to 55% by weight of the reaction medium, and - The weight ratio of the polar solvent to water in the mixture is greater than or equal to 0.4 and less than or equal to 19.0.

[0018] In the method defined above, the polar solvent of the mixture prepared in step a) or the reaction medium prepared in step A) is more particularly selected from methanol, ethanol, butanol, isopropanol, acetone, methyl ethyl ketone, glycerol, 1,3-propanediol, butanediol, 1,3-butanediol, pentanediol, hexanediol, and 2-methyl-2,4-pentanediol; according to this particular embodiment, the polar solvent is very particularly selected from ethanol and isopropanol.

[0019] In the method defined above, one or more salts may be optionally added during the preparation of the water-solvent mixture prepared in step a) or the reaction medium prepared in step A), such as salts selected from sodium chloride, calcium chloride, magnesium chloride, calcium sulfate, magnesium sulfate, calcium carbonate, magnesium carbonate, magnesium aspartate, and other monovalent or divalent salts acceptable in the cosmetics, pharmaceutical, plant protection, and food industries.

[0020] In the method defined above, the weight ratio of polar solvent to water in the mixture prepared in step a) or the reaction medium prepared in step A) is particularly greater than or equal to 1.0 and less than or equal to 4.0.

[0021] In the method defined above, the reaction medium prepared in step b) or step A) more particularly comprises, by weight 15% and less than 45% of the weight of the at least one polysaccharide, as 100% of its weight.

[0022] According to a particular aspect of the invention, if necessary, step b) of dissolving or dispersing the at least one polysaccharide or step A) of preparing the reaction medium is carried out at a temperature between 50°C and 100°C, preferably between 60°C and 80°C.

[0023] In the method defined above, step c) is carried out by adding an alkaline base, such as sodium hydroxide or potassium hydroxide, ammonium hydroxide, or an amine base, to the reaction mixture prepared in step b) or step A). ​​Sodium hydroxide is used more particularly, especially a tetramolar aqueous solution of sodium hydroxide, potassium hydroxide, ammonium hydroxide, or triethylamine. In the method defined above, in step c), the pH is more particularly adjusted to a value greater than or equal to 10.0 and less than or equal to 12.5.

[0024] In the method defined above, the weight ratio of the STMP or STPP crosslinking agent used in step d) to the at least one starting polysaccharide is greater than or equal to 0.0001 and less than or equal to 0.0700; more particularly, it is greater than or equal to 0.0003 and less than or equal to 0.0300. The crosslinking temperature can be between 5°C and 100°C, preferably between 10°C and 80°C, and ideally varies between 20°C and 70°C.

[0025] According to another specific implementation of the method defined above, the crosslinking agent used in step d) is sodium tripolyphosphate (STMP).

[0026] In the method defined above, step e) of adjusting the pH is specifically carried out using a strong acid, such as hydrochloric acid or sulfuric acid, to stop the cross-linking mechanism. This is typically done at an ambient temperature between 15°C and 35°C.

[0027] The methods defined above enable the production of polysaccharide gels in more concentrated or even solid forms, which allows them to be used industrially as an alternative to petroleum-derived polymers.

[0028] Therefore, another subject of the invention is the use of cross-linked polysaccharides or mixtures of cross-linked polysaccharides obtained by the methods defined above for thickening, stabilizing, or emulsifying detergent formulations for industrial or household use containing a polar phase. A further subject of the invention is the use of cross-linked polysaccharides obtained by the methods defined above for suspending solid particles in detergent formulations for industrial or household use containing a polar phase.

[0029] Therefore, another subject of the present invention is an aqueous formulation for industrial or household use containing a polar phase, characterized in that it contains, by weight 0.1% to 10.0%, more particularly 0.5% to 5.0%, of a cross-linked polysaccharide or a mixture of cross-linked polysaccharides obtained by the methods defined above as a thickener, stabilizer or emulsifier in the aqueous detergent formulation for industrial or household use containing a polar phase, or as a reagent capable of and intended to suspend solid particles within the aqueous detergent formulation for industrial or household use containing a polar phase.

[0030] For the purposes of this invention, industrial or household detergent formulations containing a polar phase are understood to refer to compositions designed and used for cleaning various types of surfaces, such as textile fibers, glass, ceramics, tiles, wood, metals, and composite materials, and which are liquid at 20°C. They can be used to clean contaminants from said surfaces, such as manually or by machine cleaning bottles or tableware, manually or by machine cleaning clothing, cleaning floors, grease-contaminated metal surfaces, windows, toilets, or storage tanks.

[0031] In the context of this invention, the polar phase constituting an industrial or household detergent formulation comprising a polar phase is particularly selected from water, aqueous-alcoholic mixtures such as water-ethanol, water-propanol, water-isopropanol, water-butanol, water-isobutanol, water-sec-butanol, and water-tert-butanol, and water-polyol mixtures such as water-ethylene glycol, water-propylene glycol, water-butanediol, water-glycerol, or water-1,3-propanediol.

[0032] Among these industrial or household detergent formulations containing polar phases, alkaline detergent formulations and acidic detergent formulations can be distinguished. They are typically in the form of solutions, aqueous solutions, emulsions or microemulsions with an aqueous continuous phase, emulsions or microemulsions with an oily continuous phase, aqueous gels, foams, or aerosols. They can be applied directly to the surface to be cleaned by soaking, spraying, or vaporization, or by means of any type of carrier (paper, wiping material, textiles) designed to contact the solid surface to be cleaned.

[0033] In the context of this invention, the stabilizer for industrial or household detergent formulations containing a polar phase means that the cross-linked polysaccharide or mixture of the cross-linked polysaccharides obtained by the methods defined above is capable of and intended to stabilize the formulation in emulsion or microemulsion form by imparting them a uniform appearance during storage under various conditions, more particularly at 25°C for at least one month, more particularly at 4°C for at least one month, and more particularly at 45°C for at least one month.

[0034] In the context of this invention, an agent capable of and intended to suspend solid particles in an industrial or household aqueous detergent formulation containing a polar phase means that the cross-linked polysaccharide or a mixture of the cross-linked polysaccharides obtained by the methods defined above is capable of and intended to suspend solid particles with an average apparent diameter between 1 micrometer and 5 millimeters, more particularly between 10 micrometers and 1 millimeter, which may have a variety of regular or irregular geometries, and particularly in the form of pearls, beads, rods, scales, flakes or polyhedra. Examples of such solid particles include mica, iron oxides, titanium oxides, zinc oxides or aluminum oxides, talc, silica, kaolin, clay, boron nitride, calcium carbonate or magnesium carbonate, magnesium bicarbonate, inorganic colored pigments, polyamides such as nylon-6, polyethylene, polypropylene, polystyrene, polyesters, acrylic or methacrylic polymers such as polymethyl methacrylate, polytetrafluoroethylene, crystalline or microcrystalline waxes, porous spheres, selenium sulfide, zinc pyrithione, starch, alginate, plant fibers, loofah particles, and sponge particles.

[0035] Generally, the industrial or household detergent formulations containing polar phases described in this invention also include ingredients commonly used in the field of cleaning solid surfaces or textile fibers, such as nonionic, cationic or amphoteric surfactants, cationic or nonionic polymers, defoaming or low-foaming surfactants, thickeners, enzymes, bleaching agents, corrosion inhibitors, solvents, acidic agents, alkaline agents, scale inhibitors, preservatives, fragrances, colorants, insect repellents, oxidants, detergent aids, antifouling agents, or anti-redeposition agents.

[0036] The term "detergent surfactant" refers to a surfactant that imparts to industrial or household detergent formulations containing a polar phase the ability to detach dirt from a solid surface to be cleaned and to suspend the dirt for subsequent removal during a rinsing step. These detergent surfactants can be anionic, cationic, amphoteric, or nonionic.

[0037] - Examples of anionic detergent surfactants optionally present in detergent formulations as defined above include alkyl ether sulfates, alkyl sulfates, alkyl amide ether sulfates, alkyl aryl polyether sulfates, monoglyceride sulfates, α-olefin sulfonates, alkyl sulfonates, alkyl phosphates, alkyl ether phosphates, alkyl sulfonates, alkyl amide sulfonates, alkyl aryl sulfonates, alkyl carboxylates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkyl amide sulfosuccinates, alkyl sulfoacetates, alkyl sarcosine salts, acyl hydroxyethyl sulfonates, N-acyl taurines, acyl lactates, salts of N-acylated derivatives of amino acids, salts of N-acylated derivatives of peptides, salts of N-acylated derivatives of proteins, and salts of fatty acids.

[0038] - Examples of amphoteric detergent surfactants optionally present in detergent formulations as defined above include alkyl betaine, alkylamido betaine, sulfobetaine, alkylamidoalkylsulfobetaine, imidazoline derivative, phosphobetaine, amphoteric polyacetate, amphoteric propionate, β-alanine, and N-(2-carboxyethyl)-N-(2-ethylhexyl) sodium sold under the trademark Tomamine® 30 Amphoteric 400 Surfactant.

[0039] - Examples of cationic detergent surfactants that may be present in detergent formulations as defined above include quaternary ammonium derivatives.

[0040] Examples of nonionic detergent surfactants optionally present in detergent formulations as defined above include alkyl polyglycosides containing linear or branched, saturated or unsaturated aliphatic groups comprising 8 to 16 carbon atoms; castor oil derivatives, polysorbates, coconut amides, and N-alkylamines.

[0041] Examples of acidic agents that may be present in detergent formulations as defined above include: - Inorganic acids, such as hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, sulfamic acid, hypophosphorous acid, phosphorous acid, hypochlorous acid, perchloric acid, boric acid, manganic acid, permanganic acid, chromic acid, periodic acid, iodic acid, hypoiodous acid, hydrobromic acid, hydroiodic acid, and hydrofluoric acid; - Organic acids, such as formic acid, carbonic acid, acetic acid, propionic acid, benzoic acid, salicylic acid, oxalic acid, succinic acid, glutamic acid, adipic acid, glycolic acid, lactic acid, malic acid, maleic acid, tartaric acid, citric acid, sorbic acid, dihydroacetic acid, and dimethylaminosulfonic acid. The following acids are listed: ulfamic, fumaric, glutamic, isopropylsulfamic, valeric, benzenesulfonic, xylenesulfonic, 2-ethylhexanoic, capric, caproic, cresylic, dodecylbenzenesulfonic, peracetic, chloroacetic, and gluconic acid.

[0042] Examples of alkaline agents that may be present in detergent formulations as defined above include alkali metal or alkaline earth metal hydroxides, such as sodium hydroxide, potassium hydroxide, barium hydroxide, or calcium hydroxide.

[0043] Examples of optional anti-scaling agents present in detergent formulations as defined above include the following elements: - Chelating agents that have the function of complexing calcium and magnesium ions to form water-soluble complexes that are subsequently removed during rinsing, such as sodium tripolyphosphate (STPP), ethylenediaminetetraacetate (EDTA), tetraacetylethylenediamine (TAED), methylglycine diacetate (MGDA), sodium nitrotriacetate (Na3NTA), sodium gluconate or potassium gluconate, sodium isoascorbate or potassium isoascorbate, sodium polycarboxylate or potassium polycarboxylate, and sodium citrate; - Ion exchangers that exchange their sodium ions and complex calcium and magnesium ions to form water-soluble complexes that are subsequently removed during rinsing, such as sodium zeolite or aluminosilicate, or layered sodium silicate; and - Precipitants that remove ions that cause coagulation from water by forming insoluble calcium compounds (which are subsequently removed with the dirt), such as calcium carbonate and sodium metasilicate.

[0044] According to a more specific aspect, the detergent formulation defined above includes at least one scale inhibitor selected from sodium metasilicate, sodium tripolyphosphate (STPP), ethylenediaminetetraacetate (EDTA), tetraacetylethylenediamine (TAED), methylglycine diacetate (MGDA), sodium nitrilotriacetate (Na3NTA), sodium gluconate, sodium citrate, and calcium carbonate.

[0045] Examples of nonionic defoaming or low-foaming surfactants that may be present in detergent formulations as defined above include: - Block copolymers of ethylene oxide and propylene oxide, most particularly block copolymers of ethylene oxide and propylene oxide sold under the trademarks Pluronic™, Pluronic™ PE 6100, and Pluronic™ PE 6200. - Formula R1-X-((CH2-CH(CH3)-O) u -(CH2-CH2-O) v -Y) wThe nonionic defoaming surfactant, wherein R1 represents a saturated or unsaturated, linear or branched hydrocarbon-based aliphatic radical containing 6 to 18 carbon atoms, X represents a nitrogen atom or an oxygen atom, u and v can be the same or different, each representing an integer between 1 and 50, if X represents an oxygen atom, then w equals 1, or if X represents a nitrogen atom, then w equals 1 or 2, Y represents a blocking functional group selected from linear alkyl groups containing 4 to 8 carbon atoms, such as butyl, benzyl or butylene oxide group; for example TERGITOL™ L61E and TERGITOL™ L64E; - Formula R8-O-(S') q -H refers to nonionic, low-foaming surfactants, where S' represents a reducing sugar residue selected from glucose, xylose, and arabinose, R8 represents a saturated linear or branched hydrocarbon group having 6 to 10 carbon atoms, and q' represents a decimal number greater than or equal to 1.05 and less than or equal to 5; examples include hexyl polyglucoside, 2-ethylhexyl polyglucoside, n-heptyl polyglucoside, or n-octyl polyglucoside; alkoxylated monoglycerides, alkoxylated diglycerides, and alkoxylated terpenes containing 1 to 30 oxyethylene and / or oxypropylene units, such as ethoxylated and / or propoxylated α-pinene or β-pinene, products obtained by condensation of ethylene oxide or propylene oxide with ethylenediamine, such as TETRONIC™ products sold by BASF, containing 5 to 25 moles of ethylene oxide and / or propylene oxide. Ethoxylated and / or propoxylated C8-C18 fatty acids containing ethylene oxide, ethoxylated fatty amides containing 5 to 30 moles of ethylene oxide, ethoxylated amines containing 5 to 30 moles of ethylene oxide, and alkoxylated amide amines containing 1 to 50, preferably 1 to 25, most particularly 2 to 20 moles of ethylene oxide and / or propylene oxide.

[0046] Examples of thickeners or gelling agents that may be present in detergent formulations as defined above include: - Polysaccharides composed entirely of monosaccharides, such as glucan or glucose homopolymers, glucomannoglucan, xyloglycan, and galactomannan, whose degree of substitution (DS) of D-galactose units on the main D-mannose chain is between 0 and 1, and more particularly between 1 and 0.25, such as galactomannan derived from cassia gum (DS = 0.20), locust bean gum (DS = 0.25), tara gum (DS = 0.33), guar gum (DS = 0.50), or fenugreek gum (DS = 1); - Polysaccharides composed of monosaccharide derivatives, such as sulfated galactan, especially carrageenan and agar, uronans, especially algin, alginate and pectin, hybrids of monosaccharides and uronic acids, especially xanthan gum, gellan gum, gum arabic exudate and gum arabic exudate, and glucosamine polysaccharides; - Cellulose derivatives, such as methylcellulose, ethylcellulose, hydroxypropylcellulose, silicates, starch, hydrophilic starch derivatives and polyurethane; - Inorganic thickeners, such as clay, hectorite, saponite, zinc montmorillonite, vermiculite, or colloidal silica. Examples of abrasive agents that may be present in detergent formulations as defined above include materials of natural origin, such as wood chips or kernel chips; inorganic abrasives, such as oxides, quartz, diatomaceous earth, colloidal silica; and organic abrasives, such as polyolefins, such as polyethylene and polypropylene, polystyrene, acetonitrile-butadiene-styrene resin, melamine, phenolic resin, epoxy resin, or polyurethane resin.

[0047] Examples of other solvents optionally present in the detergent formulations defined above include benzyl alcohol, chlorinated solvents, acetone, methyl ethyl ether, methyl isobutyl ether, butyl acetate, ethyl acetate, isopropyl acetate or isobutyl acetate; aromatic solvents, isoparaffins, isododecane, ethyl lactate or butyl lactate, terpenic solvents, rapeseed methyl ester, sunflower methyl ester, propylene glycol n-methyl ether, dipropylene glycol n-methyl ether, tripropylene glycol n-methyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether, propylene glycol monomethyl ether acetate, propylene glycol diacetate, propylene glycol phenyl ether, ethylene glycol phenyl ether or dipropylene glycol dimethyl ether.

[0048] Examples of enzymes that may be present in detergent formulations as defined above include proteases, amylases, lipases, cellulases, and peroxidases.

[0049] Detergent formulations for industrial or household use that contain a polar phase are typically prepared by a method comprising the following sequential steps: - Step a), preparing an aqueous medium containing water, optionally an alcohol or a polyol in a jacketed tank, wherein the heat transfer fluid is circulated in the jacket at a regulated temperature. - Step b), the at least one cross-linked polysaccharide obtained by the method described in this invention is gradually added to the aqueous medium prepared in step a) under moderate non-shear stirring at a moderate temperature between 20°C and 60°C. - Step c), in which at least one detergent surfactant is added to the medium obtained from step b), and optionally - Step d), in which one or more additional ingredients are added to the medium obtained from step c).

[0050] According to another aspect, one subject of the invention is the use of the industrial or household detergent formulations containing a polar phase as defined above for cleaning surfaces.

[0051] According to another aspect, one subject of the invention is a method for cleaning a surface, characterized by comprising at least one first step a1): applying the industrial or household detergent formulation containing a polar phase, and then at least one step b1): rinsing the surface.

[0052] In the context of this invention, the term "surface" specifically refers to floors, walls, window glass, ceramic tiles, household appliances, kitchen utensils, countertops, faucet fittings, sinks, cans for storing chemicals, food, or agricultural products, vehicle surfaces, or textile surfaces. Materials constituting these solid surfaces include, for example, glass (soda-lime glass, calcium fluoride glass, borosilicate glass, crystal glass), porcelain, earthenware, ceramics, polycarbonate or polypropylene plastics, stainless steel, silver, copper, aluminum, wood, synthetic resins, glass ceramics, or linoleum, and may be coated with paint or varnish.

[0053] In step a1) of the method defined above, the detergent formulation is applied to the surface containing the dirt to be cleaned by any means, such as by complete immersion, by spraying, or by means of a carrier composed of synthetic or natural, woven or nonwoven textile fibers or paper pre-impregnated with the composition.

[0054] In step b1) of the method defined above, rinsing of the surface to which the detergent formulation is applied is carried out during step a1) by complete immersion or by spraying with water. Step b1) can be carried out at room temperature or at a temperature between 30°C and 80°C, more particularly at a temperature between 30°C and 65°C. Detailed Implementation

[0055] The following examples illustrate the present invention, but do not limit the invention.

[0056] STMP-crosslinked xanthan gum was prepared in a water-ethanol mixture (according to the present invention). The synthesis method includes the following steps: Step A): Under mechanical stirring, load 193 g of a water-alcohol mixture of 95% ethanol and water (weight ratio 62 / 38) and 30 g of xanthan gum into a jacketed 1-liter glass reactor. Step c): Adjust the pH of the mixture prepared in step A) to 12.5 using a tetramolar aqueous solution of sodium hydroxide at 25°C. Step d): Add 0.018 g STMP (i.e., 0.06 wt% relative to xanthan gum) to the mixture obtained in step c) and heated to 50°C; maintain stirring at this temperature for 2 hours, then cool to 25°C. Step e): Adjust the pH of the reaction medium to 7 using a 5-molar concentration of pentamolar hydrochloric acid aqueous solution. Step f): Gravity filtration of the reaction medium on filter paper (average filtration of 4 µm to 7 µm). Step g): The product recovered in step f) was dried under vacuum in an oven at a constant temperature of 50°C for 16 to 20 hours; thereby obtaining 24 g of polysaccharide (P1) in the form of a white powder, with a yield of 80% (relative to the amount of xanthan gum introduced).

[0057] STMP-crosslinked xanthan gum was prepared in a water-ethanol mixture (comparative). The same method as described in the paragraph describing the preparation of STMP-crosslinked xanthan gum (P1) in water-ethanol was performed, but the pH of step c) was adjusted to 7.0 instead of 12.5. 24 g of polysaccharide (P1') was isolated as a white powder, with a yield of 80% (relative to the xanthan gum introduced).

[0058] STMP-crosslinked xanthan gum was prepared in a water-ethanol mixture (according to the present invention). The synthesis method includes the following steps: Step A): Under mechanical stirring, load 200g of a water-alcohol mixture of 95% ethanol and water (75 / 25 by weight) and 60g of xanthan gum into a jacketed 1-liter glass reactor. Step c): Adjust the pH of the mixture prepared in step A) to 12.0 at 20°C using a tetramolar aqueous solution of sodium hydroxide. Step d): Add 0.69 g STMP (i.e., 1.15% by weight relative to xanthan gum) to the mixture obtained in step c) and heated to 35°C; maintain stirring at this temperature for 1 hour, then cool to 20°C. Step e): Adjust the pH of the reaction medium to 7 using a 5-molar concentration of pentamolar hydrochloric acid aqueous solution. Step f): Gravity filtration of the reaction medium on filter paper (average filtration of 4 to 7 µm). Step g): The product recovered in step f) is dried in an oven at 50°C under vacuum for 16 to 20 hours; thereby obtaining polysaccharide (P2) in the form of a white powder.

[0059] STMP-crosslinked lipophilic xanthan gum was prepared in a water-ethanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked xanthan gum (P1) in water-ethanol was performed, but xanthan gum was replaced with chemically modified xanthan gum esterified with dodecanoate. 26 g of polysaccharide (P3) was isolated as a white powder, with a yield of 86.7% (relative to the introduced C-12 lipophilic xanthan gum).

[0060] STMP-crosslinked xanthan gum was prepared in a water-isopropanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked xanthan gum (P1) in water-ethanol was carried out, but isopropanol was used instead of ethanol. 24.5 g of polysaccharide (P4) was isolated as a white powder, with a yield of 81.7% (relative to the xanthan gum introduced).

[0061] STMP-crosslinked konjac gum was prepared in a water-ethanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked xanthan gum in a water-ethanol mixture (P2) was performed, but konjac gum was used instead of xanthan gum. The polysaccharide (P5) was isolated as a white powder.

[0062] STMP-crosslinked guar gum was prepared in a water-ethanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked xanthan gum (P2) in a water-ethanol mixture was performed, but guar gum was used instead of xanthan gum. 54.3 g of polysaccharide (P6) was isolated as a white powder, with a yield of 90.5% (relative to the amount of guar gum introduced).

[0063] STMP-crosslinked kappa-carrageenan (κ-carrageenan) was prepared in a water-ethanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked xanthan gum (P2) in a water-ethanol mixture was performed, but xanthan gum was replaced with κ-carrageenan and the medium obtained in step A) was heated at 80°C for 1 hour. 52.5 g of polysaccharide (P7) was isolated as a white powder, with a yield of 87.5% (relative to the amount of κ-carrageenan introduced).

[0064] STMP-crosslinked iota-carrageenan (i-carrageenan) was prepared in a water-ethanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked kappa-carrageenan (κ-carrageenan) (P7) in a water-ethanol mixture was performed, but iota-carrageenan was used instead of κ-carrageenan. 52.8 g of the polysaccharide (P8) was isolated as a white powder, with a yield of 88% (relative to the amount of iota-carrageenan introduced).

[0065] STMP-crosslinked iota-carrageenan was prepared in a water-ethanol mixture and in the presence of calcium sulfate (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked iota-carrageenan (i-carrageenan) in a water-ethanol mixture (P8) was performed, but 0.3 g of calcium sulfate was introduced in step A). ​​The polysaccharide was isolated as a white powder (P9).

[0066] STMP-crosslinked κ-carrageenan was prepared in a water-ethanol mixture and in the presence of calcium sulfate (according to the present invention). The same method as described in the paragraphs describing the preparation of STMP-crosslinked ι-carrageenan (P9) in a water-ethanol mixture and in the presence of calcium sulfate was performed, but κ-carrageenan was used instead of ι-carrageenan. 53.3 g of polysaccharide (P10) was isolated as a white powder, with a yield of 88.8% (relative to the amount of κ-carrageenan introduced).

[0067] STMP-crosslinked xanthan gum-i-carrageenan mixture was prepared in a water-ethanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked i-carrageenan (P8) in a water-ethanol mixture was performed, except that 54 g of xanthan gum (xanthan gum / i-carrageenan weight ratio = 9.0) was added in step A). ​​54.7 g of polysaccharide (P11) was isolated as a white powder, with a yield of 91.2% (relative to the introduced xanthan gum-i-carrageenan mixture).

[0068] STMP-crosslinked xanthan gum-i-carrageenan mixture was prepared in a water-ethanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked xanthan gum-i-carrageenan mixture (P11) in a water-ethanol mixture was performed, but the xanthan gum / i-carrageenan weight ratio was reversed. For this purpose, 6 g of xanthan gum and 54 g of i-carrageenan were used (xanthan gum / i-carrageenan weight ratio = 0.1). 54.4 g of polysaccharide (P12) was isolated as a white powder, with a yield of 90.7% (relative to the introduced xanthan gum-i-carrageenan mixture).

[0069] STMP-crosslinked xanthan gum-κ-carrageenan mixture was prepared in a water-ethanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked xanthan gum-ι-carrageenan mixture (P11) was performed, but ι-carrageenan was substituted with κ-carrageenan (xanthan gum / κ-carrageenan weight ratio = 9.0). 53.5 g of polysaccharide (P13) was isolated as a white powder, with a yield of 89.2% (relative to the introduced xanthan gum / κ-carrageenan mixture).

[0070] STMP-crosslinked xanthan gum-κ-carrageenan mixture was prepared in a water-ethanol mixture (according to the present invention). The same method as described in the paragraph describing the preparation of STMP-crosslinked xanthan gum-κ-carrageenan mixture (P12) in a water-ethanol mixture was performed, but the xanthan gum / κ-carrageenan weight ratio was reversed. For this purpose, 6 g of xanthan gum and 54 g of κ-carrageenan were used (xanthan gum / κ-carrageenan weight ratio = 0.1). 54.3 g of polysaccharide (P14) was isolated as a white powder, with a yield of 90.5% (relative to the introduced xanthan gum / κ-carrageenan mixture).

[0071] Preparation of Aqueous Gels - Evaluation of the Thickening Properties of the Prepared Polymers. The thickening properties of the STMP crosslinked polysaccharides (P1) to (P14) according to the present invention were evaluated and compared with the thickening properties of the corresponding non-crosslinked polysaccharides. The polysaccharides (P1') were characterized in the same manner, with the crosslinking step performed at a low pH outside the scope of the present invention.

[0072] - Preparation of the aqueous gel: The method for producing the aqueous gel involves introducing the amount of water required to prepare 800 grams of gel into a 2-liter beaker, which is 792 grams of water in the case of a gel containing 1% by weight of the crosslinked product. A mechanical stirrer impeller connected to a motor is placed at the bottom of the beaker. Stirring is initiated, and the necessary amount of crosslinked polysaccharide is introduced into the beaker while stirring. Stirring creates eddies that disappear as the polysaccharide becomes hydrated and forms a gel. In certain cases where the polysaccharide develops its viscosity under thermal effects, it may be necessary to heat the gel to between 50°C and 100°C to aid dissolution. A portion of the formed gel is reserved for viscosity measurement. Another portion is used to prepare a gel containing 1% polysaccharide + 0.5% sodium chloride. For this purpose, 398 grams of gel is stirred using a mechanical stirrer impeller connected to a motor, and then 2 grams of sodium chloride is added. Stirring is maintained until the sodium chloride is completely dissolved and a homogeneous gel is obtained. The gel thus prepared is evaluated 3 hours after preparation, and then 24 hours later. The viscosity of the gel was measured using a Brookfield RVT viscometer (speed 5, rotor suitable for viscosity) or a Brookfield LVT viscometer (speed 6). The experimental results are summarized in Tables 1 and 3 below.

[0073] Table 1

[0074] Table 2

[0075] Table 3

[0076] Nd: Not determined Increase in viscosity = [(Viscosity (PX) - Viscosity of the corresponding non-crosslinked polysaccharide) / Viscosity of the corresponding crosslinked polysaccharide] × 100. in conclusion - This proved the correct implementation of the cross-linking reaction, and then the cross-linked polysaccharide (~100% polymer) was separated into powder form by precipitation.

[0077] - In most cases, cross-linking polysaccharides using STMP can increase the viscosity of gels containing 1% or 2% cross-linked polysaccharides in the presence or absence of NaCl. These relative increases relative to the same uncross-linked polysaccharides vary between 3.3% (see (P6)) and 935% (see (P1)). Decreases are observed in limited quantities (see (P3), (P13), and (P14)).

[0078] - Using ethanol or isopropanol as a crosslinking cosolvent can achieve a considerable increase in gel viscosity (see (P1) and (P4)).

[0079] Examples (P1) and (P1') were able to assess the effect of pH (12.5 and 7.0, respectively) during the crosslinking step.

[0080] - The crosslinking method according to the invention was verified using single polysaccharides and mixtures of polysaccharides.

[0081] Examples of detergent formulations according to the present invention

[0082] Table 4

[0083] Table 5

[0084] Table 6

Claims

1. A method for preparing cross-linked polysaccharides, comprising the following steps: - Step a), preparing a water-polar solvent mixture, wherein the polar solvent is selected from aliphatic alcohols containing 1 to 4 carbon atoms, ketones containing 3 to 5 carbon atoms, and polyols containing 2 or 3 hydroxyl groups and 2 to 6 carbon atoms, wherein the preparation is carried out by mixing water and the polar solvent in a weight ratio of the polar solvent to water greater than or equal to 0.4 and less than or equal to 19.0; - Step b) Dispersing at least one polysaccharide in the water-polar solvent mixture prepared in step a) to obtain a reaction medium comprising, by weight 10% and less than or equal to 55% of a polysaccharide, said polysaccharide being selected from xanthan gum, xanthan gum with hydrocarbons branched with 2 to 22 carbon atoms, more particularly xanthan gum esterified with dodecanoate, guar gum and konjac gum, carrageenan, more particularly the group consisting of kappa-carrageenan and iota-carrageenan, and mixtures of two or more said polysaccharides from the group; - Step c), adjusting the pH of the reaction medium prepared in step b) to a value greater than or equal to 8.0 and less than or equal to 13.0 by adding alkali; - Step d), crosslinking the at least one polysaccharide by adding a phosphate crosslinking agent selected from sodium trimetaphosphate (STMP) and sodium tripolyphosphate (STPP) to the alkaline reaction medium obtained at the end of step c), to obtain an alkaline dispersion containing the crosslinked polysaccharide; - Step e), adjust the pH of the alkaline dispersion obtained at the end of step d) to a value less than or equal to 7.0 to obtain a non-alkaline dispersion of the at least one cross-linked polysaccharide; and - Step f), filtering the non-alkaline dispersion obtained at the end of step e) to recover the at least one intended cross-linked polysaccharide therefrom, optionally followed by: - Drying step g) to remove trace amounts of residual solvent. - or step h), atomize the at least one cross-linked polysaccharide obtained in step f) to obtain a powder therefrom.

2. The method according to claim 1, wherein steps a) and b) are simultaneous and constitute a single step A): i.e., the reaction medium is prepared by mixing water; a polar solvent selected from aliphatic alcohols containing 1 to 4 carbon atoms, ketones containing 3 to 5 carbon atoms, and polyols containing 2 or 3 hydroxyl groups and 2 to 6 carbon atoms; and polysaccharides, wherein the proportions are such that: - The weight percentage of the at least one polysaccharide is greater than 10% by weight and less than or equal to 55% by weight of the reaction medium, and - The weight ratio of the polar solvent to water in the mixture is greater than or equal to 0.4 and less than or equal to 19.

0.

3. The method according to any one of claims 1 and 2, wherein the polar solvent of the mixture prepared in step a) or the reaction medium prepared in step A) is selected from methanol, ethanol, butanol, isopropanol, acetone, methyl ethyl ketone, glycerol, 1,3-propanediol, butanediol, 1,3-butanediol, pentanediol, hexanediol and 2-methyl-2,4-pentanediol, and more particularly from ethanol and isopropanol.

4. The method according to any one of claims 1 to 3, wherein the weight ratio of the polar solvent to water in the mixture prepared in step a) or the reaction medium prepared in step A) is greater than or equal to 1.0 and less than or equal to 4.

0.

5. The method according to any one of claims 1 to 4, wherein the reaction medium prepared in step b) or step A) comprises, by weight 15% and less than or equal to 45% of the at least one polysaccharide, based on 100% of its weight.

6. The method according to any one of claims 1 to 5, wherein in step c), the pH is adjusted to a value greater than or equal to 10.0 and less than or equal to 12.

5.

7. The method according to any one of claims 1 to 6, wherein the weight ratio of the STMP or STPP crosslinking agent used in step d) to the at least one starting polysaccharide is greater than or equal to 0.0001 and less than or equal to 0.0700, more particularly greater than or equal to 0.0003 and less than or equal to 0.0300.

8. The method according to any one of claims 1 to 7, wherein the crosslinking agent used in step d) is sodium trimetaphosphate (STMP).

9. The use of cross-linked polysaccharides or mixtures of cross-linked polysaccharides obtained by the method according to any one of claims 1 to 8 for thickening, stabilizing or emulsifying industrial or household detergent formulations containing a polar phase or for suspending solid particles therein.

10. A detergent formulation for industrial or household use containing a polar phase, characterized in that... It comprises, by weight, 0.1% to 10.0%, more particularly 0.5% to 5.0% of a cross-linked polysaccharide or a mixture of cross-linked polysaccharides obtained by the method according to any one of claims 1 to 8, as a thickener, stabilizer or emulsifier in the industrial or household detergent formulation containing the polar phase, or as a reagent capable of and intended to suspend solid particles in the industrial or household detergent formulation containing the polar phase.

11. The use of the industrial or household detergent formulation comprising a polar phase as defined in claim 10 for cleaning surfaces.

12. A method for cleaning a surface, characterized in that... It includes at least one first step a1): applying the industrial or household detergent formulation containing the polar phase as defined in claim 10, and then at least one step b1): rinsing the surface.

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