Classifications

• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D7/00—Compositions of detergents based essentially on non-surface-active compounds
  • C11D7/02—Inorganic compounds
  • C11D7/04—Water-soluble compounds
  • C11D7/10—Salts
  • C11D7/14—Silicates
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D3/00—Other compounding ingredients of detergent compositions covered in group C11D1/00
  • C11D3/02—Inorganic compounds ; Elemental compounds
  • C11D3/04—Water-soluble compounds
  • C11D3/08—Silicates

Definitions

• the subject of the present invention is a detergent composition for a dishwasher, based on alkali metal silicate, non-corrosive with respect to glass, crystal, porcelain and decorations; it also relates to the use of said non-corrosive detergent composition in a dishwasher, as well as the method of washing in a dishwasher using it.
• One of the major problems encountered in the use of dishwashers is the phenomenon of irreversible corrosion of the dishes (glass, crystal, porcelain) observed following repeated washing.
• silicates as a detergency builder in detergent compositions for dishwashers is well known; some authors mention their ability to limit the corrosion of glass, porcelain and the glaze of articles (EJ Schuck, Proc. Mid-Year Meet, Chem. Spec. Manuf. assoc. (1972), vol. 58, pp 82-85; M. Hellsten, Tenside detergents, 9, Heft 4, pp 178-182 (1972); US-A-3,494,868; WO 96/17047). In this context, two types of formulas must be distinguished (W. Buchmeir, Glatech. Ber. Glass Sci. Tecnol. (1996) No. 6, pp 159-167),
• the Applicant has found a solution which makes it possible to solve the two problems at the same time, namely loss of mass and damage to the articles.
• the Applicant has hypothesized that the use of a detergent bath comprising in its chemical composition a "silicate part" analogous to that of the silica network of glass would make it possible to eliminate the phenomenon of hydrolysis and thus to limit, even remove, corrosion of the glass at the hydrolysis stage by rupture of Si-O-Si bonds in the glass network.
• a first object of the invention consists in the use, for eliminating or limiting corrosion of articles in glass, crystal, porcelain and decorations on glass or porcelain by repeated washing in the dishwasher, of a detergent composition generating a medium detergent having a concentration of protonated silicic monomer Si (OH) 4 of at least 2.5 ⁇ 10 -3 mole / liter of detergent medium, preferably of at least 3 ⁇ 10 ⁇ 3 mole / liter of detergent medium, all particularly of the order of 3 ⁇ 10 -3 to 9 ⁇ 10 -3 mole / liter of detergent medium.
• a second object of the invention consists of a process for the non-corrosive washing in the dishwasher of glass articles.
• a detergent composition generating a detergent medium having a concentration of protonated silicic monomer S OI- 4 of at least 2.5 ⁇ 10 ⁇ 3 mole / liter of detergent medium, preferably at least 3 x 10 "3 mole / liter of detergent medium, in particular of the order of 3 ⁇ 10 -3 to 9 ⁇ 10 3 mole / liter of detergent medium.
• Said detergent medium preferably has a pH greater than 9.8, very particularly of the order of 9.9 to 11.1.
• One means of obtaining this sufficient concentration of protonated silicic monomer Si (OH) 4 in the detergent bath consists in using, via a detergent composition, a sufficient quantity of at least one alkali metal silicate in order to obtain a high content of S.O2 capable of generating said monomer and of favoring the formation of said monomer by adjusting the pH of the bath by the choice of the nature of said silicate and of the other ingredients of the composition according to the silicate chosen.
• All the amorphous or crystalline soluble alkali metal silicates with a Si ⁇ 2 2 ⁇ ratio of the order of 1 to 4.2 allow the desired objective to be achieved.
• a particularly preferred means consists in using in the detergent composition at least one soluble alkali metal silicate, with an average Si ⁇ 2 M2 ⁇ molar ratio of the order of 2.5 to 4.2, preferably amorphous, making it possible to obtain in the detergent bath with a high Si ⁇ 2 content and favoring a low pH of the bath compatible with an adequate content of protonated silicic monomer Si (OH) 4.
• soluble silicate is understood to mean any silicate of which at least 50% of the silicon network is dissolved in the washing medium after 10 minutes under the washing conditions.
• average Si ⁇ 2 / 2 ⁇ molar ratio is understood to mean the ratio of the total number of moles of Si ⁇ 2 to the total number of moles of M2O originating from the alkali metal silicate (s) present in the detergent composition.
• a third subject of the invention consists of a detergent composition for a dishwasher, based on at least one alkali metal silicate, with an average Si ⁇ 2 M2 ⁇ molar ratio of the order of 1 to 4.2, preferably of of the order of 2.5 to 4.2, M representing an alkali metal, non-corrosive to glass, crystal, porcelain and decorations, generating, at the concentration of use, a medium detergent having a concentration of protonated silicic monomer Si (OH) 4 of at least 2.5 ⁇ 10 ⁇ 3 mole / liter of detergent medium, preferably of at least 3 ⁇ 10 ⁇ 3 mole / liter of detergent medium, all particularly of the order of 3 x 10 ⁇ 3 to 9 x 10 3 mole / liter of detergent medium.
• a medium detergent having a concentration of protonated silicic monomer Si (OH) 4 of at least 2.5 ⁇ 10 ⁇ 3 mole / liter of detergent medium, preferably of at least 3 ⁇ 10 ⁇ 3 mole / liter of detergent medium
• alkali metal silicate is understood below to mean both an alkali metal silicate alone and a mixture of several alkali metal silicates which may have different Si ⁇ 2 / M2 ⁇ molar ratios; the expression “average Si ⁇ 2 M2 ⁇ molar ratio” therefore corresponds either to a silicate alone, when a single silicate is present, or to a mixture of silicates, when several silicates of different molar ratios are present.
• the concentration of protonated silicic monomer Si (OH) 4 in the washing medium is a function of the concentration of total soluble SiO 2 in the washing medium and the pH of the bath. It is measured at 25 ° C and expressed in mole / liter, according to the following equation (I): [Si (OH) 4] [Total Si ⁇ 2 of the washing medium] / ⁇ 1 + 10 ⁇ P H " P K1) + 10 (2 P H -P K1 -PK2 ) , (I) equation in which: "pH” represents the pH of the washing medium at 25 ° C. .
• concentration of total soluble Si ⁇ 2 in the washing medium means the amount of Si ⁇ 2 soluble in the washing medium, originating from the soluble alkali metal silicate used.
• Equation (I) can also be written as follows:
• Curve (a) corresponds to a concentration of protonated silicic monomer Si (OH) 4 of 2.5 ⁇ 10 ⁇ 3 mole / liter of detergent medium; curve (b) corresponds to a concentration of protonated silicic monomer Si (OH) 4 of 3 x 10 "3 mole / liter of detergent medium. Three zones are delimited by these two curves:
• the areas to the left of curve (b) and between the two curves therefore correspond to concentrations of protonated silicic monomer Si (OH) 4 in the field of the invention, the area to the left of curve (b) corresponding to the area preferential of the invention.
• the concentration of protonated silicic monomer Si (OH) 4 in the detergent medium is of the order of 3 ⁇ 10 3 to 9 ⁇ 10 ⁇ 3 mole / liter of detergent medium.
• Said detergent composition can be in solid form (powder, tablets), in liquid form or in gel form.
• concentration of use of a detergent composition for dishwashers is generally of the order of 3 to 12 g / liter of detergent bath. This is more precisely of the order of 4 to 10 g / liter for a powder composition, of the order of 3 to 6 g / liter for a composition in tablet form and of the order of 4 to 12 g / liter for a liquid composition or in the form of a gel.
• the pH of the washing medium is regulated by the nature and the amount of the alkali metal silicate and of the other additives influencing the pH present in the composition. This is preferably set to a value greater than 9.8, more particularly to a value of the order of 9.9 to 11.1.
• the areas to the left of curve (B) and between the two curves therefore correspond to concentrations of protonated silicic monomer Si (OH) 4 in the field of the invention, the area to the left of curve (B) corresponding to the area preferential of the invention.
• the amount by dry weight of alkali metal silicate generally represents, depending on the form of detergent composition chosen, of the order of 5 to 55%, preferably of the order of 10 to 40% of the dry weight of said composition.
• the amount of silicate represents of the order of 5 to 55%, preferably of the order of 10 to 40% of the dry weight of said composition
• the amount of silicate represents of the order of 5 to 40%, preferably of the order of 10 to 30% of the dry weight of said composition.
• FIGS. 2 to 7 define which conditions are best suited to carrying out the invention, depending on the nature of the silicate chosen and the form of detergent composition sought.
• Those skilled in the art can also, for concentrations of use different from those mentioned above and / or for silicates of molar ratio Si ⁇ 2 / Na2 ⁇ other means, by general study of Figure 1 and / or at l Using equation (I) determine the best conditions for carrying out the invention.
• This analysis makes it possible to recommend - for a detergent composition used at a concentration of 6 g / liter, with a pH of the detergent medium for example of 10.5, the use in said detergent composition. at least about 30%, preferably at least about 36% of sodium metasilicate. at least about 22%, preferably at least about 27% of sodium disilicate
• the pH of the detergent medium is then adjusted by the choice and the quantities of the other ingredients influencing the pH of the detergent composition.
• the usual additives present in detergent compositions for dishwashers and making it possible to influence the pH of the detergent medium are mainly
• alkali metal phosphates orthophosphates, pyrophosphates, polyphosphates such as tripolyphosphates in particular
• alkali metal hydroxides ... - acidifying additives soluble in the washing medium such as
• carboxylic or polycarboxylic acids generating sequestering or dispersing compounds in the washing medium citric, glutamic, glutaric, gluconic, tartaric acids, polyacrylic acids or their copolymers, fatty acids .
• the detergent compositions for dishwashers comprise at least one surfactant in an amount which can range from 0.5 to 10%, preferably of the order of 1 to 5%, by weight of said detergent composition expressed as dry matter.
• anionic surfactants such as alkali metal soaps (alkaline salts of C8-C24 fatty acids), alkali sulfonates (Cb- alkylbenzene sulfonates)
• C13, C12-C16 alkyl sulfonates C13, C12-C16 alkyl sulfonates), oxyethylenated and sulfated C6-C16 fatty alcohols, oxyethylenated and sulfated C8-C13 alkylphenols, alkali sulfosuccinates (C12-C16 alkyl sulfosuccinates) -
• builders agents improving the surface properties of surfactants
• soluble mineral phosphates of alkali metals in particular the tripolyphosphates of alkali metals in an amount of 0 to 70% of the total weight of detergent composition expressed as dry matter
• organic phosphonates such as those of the DEQUEST® range from MONSANTO at a rate of 0 to 2% of the total weight of detergent composition expressed as dry matter;
• nitriloacetic acid N acid, N-dicarboxymethyl-2-aminopentane dioic acid, ethylenediamine tetraacetic acid, diethylenetriamine pentaacetic acid, at a rate of 0 to 10% of the total weight of detergent composition expressed as dry matter; . citric acid, gluconic acid or tartaric acid or their salts from 0 to
• acetylated bleaching activators such as N, N, N ', N'-tetraacetylethylenediamine (TAED) or chlorinated products of the chloroisocyanurate type for solid compositions, or chlorinated products of the hypochlorite type of alkali metals for liquid compositions, at a rate of 0 to 30% of the total weight of said detergent composition expressed as dry matter;
• acetylated bleaching activators such as N, N, N ', N'-tetraacetylethylenediamine (TAED) or chlorinated products of the chloroisocyanurate type for solid compositions, or chlorinated products of the hypochlorite type of alkali metals for liquid compositions, at a rate of 0 to 30% of the total weight of said detergent composition expressed as dry matter;
• alkaline agents such as borates, carbonates, bicarbonates, sesquicarbonates of alkali metals, at a rate of 0 to 50% of the total weight of said composition expressed as dry matter;
• any type of soluble alkali metal silicate can be used in the detergent composition of the invention.
• anhydrous and / or hydrated metasilicates (S 2 O 2 molar ratio of 1) in the form of powder or granules can be present according to the invention in a detergent composition in powder or in tablets.
• the pH of the detergent bath may be adjusted to a pH greater than 9.8, preferably of the order of 9.9 to 11.1, by the presence in said composition of an acidifying agent or additive such as citric acid. , sodium bicarbonate, sodium sesquicarbonate or any other acidifying agent.
• the amorphous "disilicates" may be present, in atomized form compacted in a detergent composition in powder or in tablets, in the form of a concentrated solution generally at approximately 45 % of dry matter in a liquid detergent composition or in gel form; they can also be present in the form of solid preformulation in a powder or tablet composition, preformulation, preferably in the form of cogranules, obtained by adsorption and / or absorption of a concentrated solution of alkali metal silicate generally at about 45% dry matter on a soluble mineral support of the alkali metal tripolyphosphate type and / or alkali metal carbonate and / or alkali metal bicarbonate and / or alkali metal sesquicarbonate and / or alkali metal sulfate, the amount of water remaining associated with the silicate corresponding to a water associated with silicate / silicate ratio expressed as dryness of at least 20/100, preferably
• water associated with silicate means the water of the supported solution which is not combined with the mineral support, in particular in the form of crystallized hydrate. This can be measured in particular by X-ray diffraction, NMR of the solid, proton, phosphorus, etc.).
• the pH of the detergent bath may be adjusted to a pH greater than 9.8, preferably of the order of 9.9 to 11.1, by the presence in said composition of an acidifying agent or additive such as citric acid. , sodium bicarbonate, sodium sesquicarbonate or any other acidifying agent.
• the alkali metal silicate, especially sodium silicate, used in the detergent compositions of the invention is amorphous and has an average Si ⁇ 2 M2 mol molar ratio of the order of 2.5 to 4.2.
• a detergent composition depends on the form of the detergent composition for which it is intended, namely a composition solid detergent (powder or tablets) or a liquid or gel detergent composition.
• Said alkali metal silicate having an average Si ⁇ 2 / 2 ⁇ molar ratio of the order of 2.5 to 4.2 can be used in particular in the form of an aqueous solution concentrated generally at about 25 to 50% of dry matter or a liquid preformulation in a liquid or gel detergent composition, or in the form of a solid preformulation in a powder or tablet composition.
• a solid detergent composition When it is intended for a solid detergent composition, it can preferably be used in the form of a solid preformulation, in particular in the form of cogranules, obtained by adsorption and / or absorption of a concentrated solution of alkali metal silicate.
• a solid preformulation in particular in the form of cogranules, obtained by adsorption and / or absorption of a concentrated solution of alkali metal silicate.
• the quantity of water remaining associated with the silicate corresponding to a water-associated with silicate / silicate ratio expressed as dry of at least 20/100, preferably at least 30/100.
• non-water-soluble mineral supports mention may be made of natural or synthetic, amorphous or crystalline sodium silicoaluminates, calcium carbonate, clays, magnesium, calcium silicates, silica, etc.
• the alkali metal tripolyphosphate the alkali metal carbonates, the alkali metal bicarbonates, the alkali metal sesquicarbonate, the alkali sulfates ...
• the pH of the detergent bath can be adjusted to a pH greater than 9.8, preferably of the order of 9.9 to 10.8, by the presence in said composition of an alkalizing agent or additive or of an acidifying agent or additive.
• a first type of solid preformulation consists of cogranules obtained by adsorption and / or absorption of a concentrated solution of alkali metal silicate molar ratio Si ⁇ 2 / M2 ⁇ average of the order 2.5 to 4.2, preferably l '' order 2.6 to 3.5, adsorbed and / or absorbed on at least one water-soluble mineral support compatible with the desired pH, in particular of the sodium sesquicarbonate type and / or mixtures of sodium carbonate and sodium bicarbonates and / or preferably sodium tripolyphosphate, the weight ratio, expressed as dry, silicate / mineral support being of the order of 20/80 to 60/40, preferably of the order of 25/75 to 50/50, and optionally drying until the amount of water present in said preformulation represents of the order of 10 to 3
• a first particular type of solid detergent composition which is the subject of the invention consists of a solid detergent composition as described above, in which the alkali metal silicate has an average Si ⁇ 2 / 2 ⁇ molar ratio of the order of 2 , 5 to 4.2, preferably of the order of 2.6 to 3.5, and is implemented via said first type of solid preformulation, preformulation whose pH at its concentration in the washing medium is greater than 9, 8, preferably of the order of 9.9 to 10.8, and this in accordance with equation (I) mentioned above.
• a second type of solid preformulation consists of cogranules obtained by adsorption and / or absorption of a concentrated solution of alkali metal silicate average Si ⁇ 2 / M2 ⁇ molar ratio of the order of 3 to 4.2, preferably of the order 3.3 to 4, adsorbed and / or absorbed on sodium carbonate, the weight ratio, expressed as dry, silicate / carbonate being of the order of 40/60 to 80/20, preferably of the order of 50 / 50 to 70/30, and optionally drying until the amount of water present in said preformulation represents of the order of 15 to 35% of the weight of said preformulation, and the amount of water remaining associated with the silicate corresponds to a water ratio associated with silicate / silicate expressed as dry of at least 20/100, preferably at least 30/100.
• a second particular type of solid detergent composition which is the subject of the invention consists of a solid detergent composition as described above, in which the alkali metal silicate has an average Si ⁇ 2 / 2 ⁇ molar ratio of the order of 3 to 4.2, preferably of the order of 3.3 to 4, and is implemented by means of said second type of solid preformulation, preformulation whose pH at its concentration in the washing medium is greater than 9.8 , preferably of the order of 9.9 to 10.8, and this in accordance with equation (I) mentioned above.
• silicate When said silicate is intended for a liquid detergent composition or in the form of a gel, the latter has an average SÎO2 / M2O molar ratio of the order of 2.5 to 3.5, preferably of the order of 2.6 to 3 , 3; it is used in the form of a concentrated aqueous commercial solution containing approximately 25 to 50% of dry matter, or of a liquid preformulation in the form of a dispersion in said concentrated solution of silicate of a water-soluble mineral compound.
• One type of liquid preformulation consists of a dispersion in a concentrated silicate solution with an average Si ⁇ 2 / 2 ⁇ molar ratio of the order of 2.5 to 3.5, preferably of the order of 2.6 to 3.3 at about 25 to 50% of dry matter, of a water-soluble mineral compound sodium tripolyphosphate, preferably atomized, and / or sodium carbonate, the weight ratio, expressed as dry, silicate / water-soluble mineral compound being of the order of 70/30 to 30/70, preferably of the order of 60/40 to 35/65, the amount of water present in said preformulation representing of the order of 40 to 65% of the weight of said preformulation.
• a particular type of liquid detergent composition which is the subject of the invention consists of a liquid detergent composition as described above, in which the alkali metal silicate has an average Si ⁇ 2 / M2 ⁇ molar ratio of the order of 2.5 to 3.5, preferably of the order of 2.6 to 3.3, and is implemented by means of said type of liquid preformulation, preformulation whose pH at its concentration in the washing medium is higher to 9.8, preferably of the order of 9.9 to 10.9, and this in accordance with equation (I) mentioned above.
• the concentration of Si (OH) 4 is calculated in accordance with equation (I), from the measurement of the pH of the washing medium and the amount of total Si ⁇ 2.
• the temperature cycle chosen is 65 ° C; the dose of detergent composition used for each wash is 30 g for a volume of wash water of 5 liters; after each wash-rinse-dry cycle, the door is left closed for 10 minutes and then opened for 10 minutes.
• the corrosion evaluation is done visually with a scale ranging from 1 to 5 points, taking as reference the glasses in new condition, by 9 trained people.
• the measurement of the relative mass loss (PM) of the samples makes it possible to quantify the thickness of the damaged (dissolved) surface; it is expressed in thousands of%. This corresponds to
• composition of the L3 formulation is close to that of the commercial formulations.
• compositions are used at a rate of 32 g per wash. Corrosion tests are carried out as described above, on standard white glasses (wine and fruit flask, round) and on standard decorated glasses (cherry motif and red stripe motif), after 100 cycles of washing.
• This simplified glass corrosion test reproduces certain washing conditions for dishwasher machines, in particular washing, rinsing and drying cycles.
• the glass used is made up of microscopy slides of dimension 2.5 ⁇ 7.5 cm, previously cleaned with ethanol, slides whose composition given below is close to that of table glasses.
• 200 ml of an aqueous washing solution containing 6 g / l of product to be tested are introduced into the container.
• the container is introduced and kept in an oven at 65 ° C for 1 hour.
• a glass slide is completely immersed in an inclined position.
• the container is then closed, then placed in an oven at 65 ° C.
• the blade is taken out of the container after 16 hours, rinsed twice on each side with permuted water using a wash bottle, touched with a finger to remove the film which may have formed, dried in ambient air for 2 hours.
• the slide is weighed after cooling to room temperature and the change in relative mass (in% x 1000) is calculated. The test is repeated another time to confirm the results.
• Corrosion visible to the eye is evaluated, compared with a reference blade not subjected to the test. Finally, the pH of the solutions is measured at room temperature before immersion of the slide and at the end of the experiment.
• Example 15 16 17 18 Cogranulate carbonate / silicate formulation 60 60 60 60 citrate 17 0 17 0 sodium sulfate 0 17 4.5 21.5 polyacrylate 6 6 6 6 6 paraffin 0.5 0.5 0.5 0.5 0.5 0.5 0.5 surfactant no -ionic 2 2 2 2 bleaching system 10 10 10 (perborate, 1 H? 0 + TAED **) phosphonate 4.5 4.5 0 0

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  • 1996-11-20 FR FR9614137A patent/FR2751341B1/fr not_active Expired - Fee Related
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