Classifications

• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
  • C04B28/24—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing alkyl, ammonium or metal silicates; containing silica sols
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D1/00—Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances
  • C09D1/02—Coating compositions, e.g. paints, varnishes or lacquers, based on inorganic substances alkali metal silicates
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
  • C04B28/24—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing alkyl, ammonium or metal silicates; containing silica sols
  • C04B28/26—Silicates of the alkali metals
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/60—Additives non-macromolecular
  • C09D7/61—Additives non-macromolecular inorganic
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L58/00—Protection of pipes or pipe fittings against corrosion or incrustation
  • F16L58/02—Protection of pipes or pipe fittings against corrosion or incrustation by means of internal or external coatings
  • F16L58/04—Coatings characterised by the materials used
  • F16L58/06—Coatings characterised by the materials used by cement, concrete, or the like
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2103/00—Function or property of ingredients for mortars, concrete or artificial stone
  • C04B2103/46—Water-loss or fluid-loss reducers, hygroscopic or hydrophilic agents, water retention agents
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
  • C04B2111/00482—Coating or impregnation materials
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
  • C04B2111/00482—Coating or impregnation materials
  • C04B2111/00525—Coating or impregnation materials for metallic surfaces
• • C—CHEMISTRY; METALLURGY
  • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
  • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
  • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
  • C04B2111/56—Compositions suited for fabrication of pipes, e.g. by centrifugal casting, or for coating concrete pipes

Definitions

• the present invention relates to the field of pipes or tanks intended to be in contact with water, in particular the field of pipe or tank elements coated internally with coatings based on a mineral binder such as cement mortars for transporting or store drinking water or raw water intended for the production of drinking water (raw water being water that has not undergone any treatment and can supply a drinking water production station).
• a mineral binder such as cement mortars for transporting or store drinking water or raw water intended for the production of drinking water (raw water being water that has not undergone any treatment and can supply a drinking water production station).
• the invention relates to a treatment of the internal surfaces of these containers intended to be in contact with water, and a container, such as a pipe or a reservoir, thus treated.
• drinking water we mean hereinafter mainly drinking water strictly speaking, but also where appropriate raw water when it is intended for the production of drinking water.
• slag cement makes it possible to widen the field of application of the coating, but does not make it possible to cover all the drinking and raw water.
• a binder from aluminous cement makes it possible to remedy this in large part and provides an improvement in abrasion resistance, but at the cost of releasing aluminum in quantities that may exceed the normative thresholds.
• the use of a chemically very stable mineral binder such as a geopolymer, having a very low soluble alkaline reserve also compromises the protection of the metal in the case for example of pipes or tanks made of steel or comprising reinforced concrete reinforcements. .
• the present invention has therefore sought to improve the protection of containers intended to transport or contain water, in particular drinking water, against degradation which may occur over time, in particular to reduce again, the possible release of species which must not exceed the normative thresholds, in particular to reduce the leaching of aluminum from coatings based on mineral binder, in particular cement, from containers intended to receive (transport or contain) water.
• the present invention thus provides a treatment composition, in particular (a composition) for impregnating a coating, in particular a coating based on an inorganic binder, in particular (a coating) based on a cementitious binder, this coating being in particular the internal coating of a container intended to receive water, in particular drinking water, this composition being in the form of a solution comprising:
• At least one alkali silicate and at least one source of lithium in particular at least one alkali silicate and at least one separate source of lithium, the total content of lithium source (s) in the solution being in particular less than 10% by weight, or
• This treatment is intended to impregnate the mineral binder-based coating covering the internal surface of the containers intended to receive water, this treatment thus selected not remaining on the free surface of said coating and not generating a layer thereon. reported, as is the case with other existing treatments, but impregnating said coating to an impregnation depth typically of at least 50 ⁇ m, and preferably between 100 and 500 ⁇ m, thus allowing enhanced protection against leaching aluminum of said coatings based on inorganic binder, in particular on inorganic cement-based binder (or cementitious binder).
• free surface of the coating is meant the inner surface of the coating, potentially in contact with water.
• impregnation composition therefore means a composition which does not remain on the free surface of the coating on which it is deposited and does not generate an added layer on said free surface, but therefore impregnates said coating in depth without remaining on the surface (this impregnation therefore being an impregnation by absorption).
• the present invention also relates to a container, such as a pipe or water tank element, in particular drinking water (or "for water. potable ”or“ intended to receive potable water ”), this container having an internal coating based on a mineral binder, in particular cement, said internal coating being impregnated to a depth of at least 50 ⁇ m, preferably between 100 and 500 ⁇ m, and in particular between 100 and 300 ⁇ m, with at least one silicate, in particular with a solution comprising:
• At least one alkali silicate and at least one source of lithium in particular at least one alkali silicate and at least one separate source of lithium, the total content of lithium source (s) in the solution being in particular less than 10% by weight, or
• the inorganic binder is advantageously a cementitious binder.
• the alkali silicate is preferably (at least) a sodium silicate, a potassium silicate or a lithium silicate, and particularly advantageously is a (or at least one) sodium silicate or one (or at least one) silicate. potassium.
• the alkali silicate is a potassium silicate, which contributes to less precipitation of Na2CO3 at the surface.
• the alkali silicate in particular of potassium, preferably has an S1O2 / R2O molar ratio ranging from 1 (inclusive) to less than 5 (5 being excluded), in particular ranging from 1 to 4 (1 and 4 being included) or between 1 and 4, in particular ranging from 2 to 3 (2 and 3 being included) or between 2 and 3, where R denotes the alkali metal.
• Silicates with too low a ratio are too reactive, while silicates with too high a ratio are poorly soluble and lend themselves less easily to impregnation.
• the mass concentration (or by weight or by mass) of alkali silicate in the solution is preferably at least 2%, in particular is between
• the or each lithium source can in particular be a lithium salt. It is preferably chosen from lithium carbonate, lithium sulphate or other organic lithium salts (for example lithium acetate), or even from lithium hydroxide, lithium silicate, and their derivatives.
• the most preferred salts are lithium sulfate, lithium carbonate and lithium hydroxide. A mixture of two or more of these salts is also suitable.
• the lithium silicate can both play the role of alkali silicate and of lithium source.
• the case in which the only alkali silicate present and the source of lithium are one and the same compound is preferably excluded in the present invention, the lithium silicate not only exhibiting a high cost which is not compatible with such an embodiment but such an embodiment. mode also involving too large a quantity (for reasons in particular of sanitary conformity) of lithium after deposition having regard to the quantities of composition applied (to obtain the desired effects) according to the present invention (preferably between 50 and 500 g / m 2 as indicated later).
• the composition comprises at least one lithium silicate
• this silicate in this case being both a source of lithium and all or part of the alkali silicate (s) within the meaning of the present invention
• the lithium source is one (or at least one) other compound than a lithium silicate
• the total content of lithium source (s) is preferably strictly less than 10% by weight, thus limiting in particular the risk of excessively high amounts of lithium being released into water with regard to the amounts of composition applied according to the present invention.
• the solution therefore comprises, in its first variant (the second variant being the use of at least one organic orthosilicate), at least one alkali silicate and a separate lithium source, in the sense where, either it does not include any lithium silicate, or when it does include one, the solution then also comprises another source of lithium than a lithium silicate and / or at least one other alkali silicate (for example sodium or potassium), and / or, preferably also according to the invention, the total content of lithium source (s) in the solution is less than 10% by weight.
• the alkaline silicate (s) according to the invention is (are) made up entirely or mainly of silicates other than lithium silicate.
• the source of lithium combined with the alkali silicate delays the reaction with the calcium ions without disturbing the formation of major hydrates such as hydrated calcium silicates and hydrated calcium silico-aluminates (CSH and CASH in cementitious notation), and thus makes it possible to ensure the deep penetration of the treatment composition. Without this combination, the silicate would react immediately on the surface with the calcium ions from the binder, causing the formation of a dense layer on the surface which does not allow deep penetration of the composition.
• the total content of lithium source (s) in the solution or in the treatment composition according to the invention is in particular less (strictly) than 10% by weight, in particular between 0.05% and 10%, and preferably is less than or equal to 2%, in particular between 0.05 and 2%, in particular between 0.05 and 1%, preferably between 0.10 and 1.0% by weight, or even between 0.15 and 0.50 % in weight.
• the total content corresponds to the sum of the contents of each lithium source when the solution contains several.
• Advantageous treatment compositions according to the invention are, for example, aqueous solutions comprising a potassium silicate, in particular with an S1O2 / K2O molar ratio of between 1 and 5, in particular between 1 and 4 or ranging from 1 to 4, or even between 2 and 3 or ranging from 2 to 3, said silicate preferably being in a mass concentration of between 5 and 40%, more particularly between 10 and 30%, said solutions further comprising a source of lithium chosen from lithium sulfate (L12SO4 ), lithium hydroxide (LiOH), lithium silicate and lithium carbonate.
• a source of lithium chosen from lithium sulfate (L12SO4 ), lithium hydroxide (LiOH), lithium silicate and lithium carbonate.
• the content of lithium source (s) in the treatment composition / in the solution according to the invention is in particular between 0.05 and 10%, and preferably is less than or equal to 2%, in particular between 0, 05 and 2%, in particular between 0.05 and 1%, preferably between 0.10 and 1%, or even between 0.15 and 0.50% by weight for said compositions.
• organic orthosilicate is meant an organic salt of the orthosilicate.
• the organic orthosilicate is preferably chosen from tetramethyl orthosilicate (TMOS) and tetraethyl orthosilicate (TEOS).
• TMOS tetramethyl orthosilicate
• TEOS tetraethyl orthosilicate
• the organic orthosilicate is preferably tetraethyl orthosilicate (TEOS).
• TMOS tetramethyl orthosilicate
• TEOS tetraethyl orthosilicate
• the combination with a lithium source is not necessary, said composition penetrating in depth without initial formation of a dense layer on the surface.
• silicate-based treatment compositions selected according to the invention are in the form of a liquid composition (or solution) in which the silicates, dissolved in metastable form, are capable of precipitating inside the coating near the surface. surface, under the effect of contact with the mineral binder of the coating present inside the container.
• the solution is preferably an aqueous solution.
• the solution can be pure orthosilicate or orthosilicate in an organic solvent, the solvent preferably being an alcohol. Alcohol is typically ethanol or isopropanol.
• the mass concentration of organic orthosilicate in the solution is preferably at least 2%, in particular between 10 and 30%.
• the composition according to the invention comprises less than 0.5% by weight of other components.
• the content of components other than alkali silicate (s), lithium source (s), organic orthosilicate (s) and aqueous or organic solvent (s) is less than 0.5% by weight.
• the composition generally advantageously comprises at least one surfactant, so as to facilitate impregnation, this surfactant preferably being nonionic. Mention may in particular be made of alkylpolyglucosides and ethoxylated fatty alcohols.
• the total surfactant content in the solution is preferably at least 0.01%, in particular at least 0.05%, or even between 0.1 and 0.5% by weight.
• the composition is advantageously devoid of components considered to be pollutants with regard to the quality of the water (including for example heavy metals, etc.), just as apart from the surfactants, it is devoid of any other organic component of non-reactive type with hydrated compounds or (non-hydrolyzable type) which would be likely to remain present after application of the composition. It is also devoid of any hardener, their presence being able to lead to the formation of a surface layer contrary to the desired impregnation.
• the treatment according to the invention makes it possible to better preserve the quality of the water transported or stored in contact with a coating based on a mineral binder, in particular cement (coating in particular of the “cement mortar” type), in particular by reducing the aluminum leaching.
• a coating based on a mineral binder in particular cement (coating in particular of the “cement mortar” type)
• cement coating in particular of the “cement mortar” type
• a large amount of Ettringite is detected on the surface of cement mortar coatings, Ettringite being a mineral phase rich in aluminum and capable of dissolving in contact with drinking water. or raw.
• Ettringite being a mineral phase rich in aluminum and capable of dissolving in contact with drinking water. or raw.
• the aluminum is thus mainly incorporated in an environment typical of CSH phases, thus forming very stable CASH phases in which the aluminum is trapped, the decrease in the leaching of the aluminum thus resulting from this trapping in very stable phases by reaction of the alkali silicate with the Ettringite-type phases initially present in the binder of the cementitious coating (or coating in cement mortar).
• the treatment thus makes it possible to form under the surface of the coating a barrier layer limiting the release of aluminum ions, preserving both the composition of the water in contact with the coating and the structural integrity of the latter.
• the treatment according to the invention thus makes it possible to functionalize the surface of a coating based on a mineral binder, in particular cementitious, without changing the formulation of said coating before treatment.
• the treatment with the composition according to the invention acting from the surface and inside the coating this makes it possible to overcome any adhesion problem; moreover, no surface preparation is necessary beforehand.
• the treatment can be applied during the manufacture of the container in the factory, on a stockyard or also on an installation site. It can also be applied in rehabilitation.
• the present invention also relates to a method of treatment (this method being in particular a method of impregnation or treatment by impregnation) of a container, in particular of the internal coating of a. container, said container having to receive water (pipe or tank elements), in particular drinking water, said coating being based on a mineral binder, in particular cementitious, in particular being a coating of cement mortar, process wherein the treatment composition according to the invention is applied to the interior of said container, in particular to the surface of said internal coating.
• the treatment can be carried out by means of a brush, a paint brush, by spraying, by immersion or by pouring (for example in the case of a rotating pipe).
• the coating may have been dried before treatment.
• a heat treatment and controlled humidity can be carried out in order to control the precipitation reactions.
• Such heat treatment can use temperatures up to 80 ° C.
• the treatment composition is deposited so as to apply between 50 and 500 g / m 2 , in particular between 100 and 300 g / m 2 (the limits also being included), of the composition according to the invention to the surface of the internal coating.
• This ratio corresponds to the weight of solution relative to the surface of the treated coating.
• the interior coating based on a mineral binder, in particular cementitious, to be treated generally comprises at least one binder, in particular hydraulic, and in particular based on (or formed from) at least one cementitious binder.
• cementitious binders mention may in particular be made of Portland cements, aluminous cements, sulphoaluminous cements, belitic cements, blast furnace slag cements and pozzolanic mixture cements optionally comprising fly ash, silica smoke, limestone, calcined shale and / or natural or calcined pozzolans.
• the binder is a blast furnace slag cement.
• the binder is generally formed predominantly (at least 75% by weight of the binder, and generally at least 90% by weight of the binder), or even solely of a hydraulic binder of the cement type.
• the coating is also advantageously a cement mortar, its composition also advantageously containing aggregates, aggregates, sands, and / or fillers (finely ground mineral fillers) limestone and / or siliceous, playing in particular on the rheology, the hardness or the final appearance of the product.
• the mortar composition can also include initially or in the final mortar coating, other additives such as rheological or plasticizing agents, accelerators and / or retarders, and other agents for improving setting, hardening and / or the stability of the mortar after application or to adjust the workability, application or impermeability of the mortar.
• additives such as rheological or plasticizing agents, accelerators and / or retarders, and other agents for improving setting, hardening and / or the stability of the mortar after application or to adjust the workability, application or impermeability of the mortar.
• the treatment composition according to the invention can be used advantageously to treat the interior coatings based on a mineral binder, in particular cementitious, of containers intended to receive water, these containers possibly being in particular gray or ductile iron pipes coated.
• a mineral binder in particular cementitious
• these containers possibly being in particular gray or ductile iron pipes coated.
• the present invention also relates to the use of the treatment composition described above for reducing the leaching of aluminum from coatings based on mineral binder, in particular cementitious, of containers intended to receive water, in particular drinking water. .
• the treatment composition used was a solution composed of soluble potassium silicate of S1O2 / K2O molar ratio of 2.45 and in a mass concentration of about 20% and a mixture of lithium sulfate (L12SO4) in a mass concentration. 0.15% and lithium hydroxide (LiOH), also in a mass concentration of 0.15%.
• the treatment was applied to the surface of an internal coating of a ductile iron pipe, the coating being of CEMIII / B slag cement mortar, at a surface concentration of 150 g / m 2 .
• the treatment was applied in two different ways:
• the specimens (with a height and a diameter of 200 mm) were tested a few weeks after treatment according to the normative leaching protocol of standard EN 14944-3, and compared with the results of an untreated coating a few weeks after manufacture, as well as those of an untreated coating aged one and a half years.
• the impregnation treatment according to the invention made it possible to reduce the leaching of aluminum by a factor of at least 20 compared to the untreated examples in the case of impregnation after natural ripening. In the case of impregnation on a one and a half year old coating, this treatment surprisingly reduced the leaching of aluminum to below detection limits.
• FIG. 1 is an X-ray diffraction pattern performed on an untreated hydrated CEM III / B slag cement paste. A certain amount of Ettringite was detected, this aluminum-rich mineral phase being liable to dissolve on contact with drinking or raw water.
• FIG. 2 is an X-ray diffraction pattern performed on a hydrated CEM III / B slag cement paste treated with the example composition. It shows that after treatment with impregnation, the peaks corresponding to the existence of Ettringite have disappeared. Surprisingly, this treatment with an alkali silicate solution therefore converted the hydrates rich in aluminum into amorphous phases (invisible by X-ray diffraction).
• FIG. 3 represents three NMR spectra.
• the analysis by NMR spectroscopy of aluminum was carried out on anhydrous CEM III / B slag cement (curve A), on this same hydrated cement (curve B), as well as on this hydrated cement then treated by impregnation with composition according to the invention (curve C).
• the aluminum was mainly incorporated in the slag (bump at 60 ppm).
• the aluminum was mainly incorporated in Ettringite-type phases (peaks at 15 ppm), in a manner consistent with the analysis by X-ray diffraction.
• the aluminum was predominantly incorporated in a typical environment of HSCs (displacement at 70 ppm), thus forming CASHs in which the aluminum was trapped, thus causing, as seen above, a decrease in the leaching of the aluminum.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Inorganic Chemistry (AREA)
• Ceramic Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Structural Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Paints Or Removers (AREA)

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• 2019
  • 2019-10-17 FR FR1911582A patent/FR3102183B1/fr active Active
• 2020
  • 2020-10-15 EP EP20789188.8A patent/EP4045473A1/de active Pending
  • 2020-10-15 BR BR112022003955A patent/BR112022003955A2/pt unknown
  • 2020-10-15 WO PCT/EP2020/079125 patent/WO2021074341A1/fr unknown
  • 2020-10-15 CN CN202080005795.9A patent/CN113195643A/zh active Pending

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