Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B3/00—Cleaning by methods involving the use or presence of liquid or steam
  • B08B3/04—Cleaning involving contact with liquid
  • B08B3/08—Cleaning involving contact with liquid the liquid having chemical or dissolving effect
• • 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
  • C11D1/00—Detergent compositions based essentially on surface-active compounds; Use of these compounds as a detergent
  • C11D1/66—Non-ionic compounds
  • C11D1/72—Ethers of polyoxyalkylene glycols
• • 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
  • C11D3/0005—Other compounding ingredients characterised by their effect
  • C11D3/0073—Anticorrosion compositions
• • 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
  • C11D3/042—Acids
• • 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
  • C11D3/046—Salts
  • C11D3/048—Nitrates or nitrites
• • 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
  • C11D3/16—Organic compounds
  • C11D3/20—Organic compounds containing oxygen
  • C11D3/2003—Alcohols; Phenols
  • C11D3/2041—Dihydric alcohols
• • 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
  • C11D3/16—Organic compounds
  • C11D3/20—Organic compounds containing oxygen
  • C11D3/2075—Carboxylic acids-salts thereof
  • C11D3/2082—Polycarboxylic acids-salts thereof
• • 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
  • C11D3/16—Organic compounds
  • C11D3/26—Organic compounds containing nitrogen
  • C11D3/32—Amides; Substituted amides
  • C11D3/323—Amides; Substituted amides urea or derivatives thereof
• • 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
  • C11D7/08—Acids
• • 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
  • C11D7/22—Organic compounds
  • C11D7/26—Organic compounds containing oxygen
  • C11D7/265—Carboxylic acids or salts thereof
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
  • C23C22/78—Pretreatment of the material to be coated
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
  • C23G1/04—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors
  • C23G1/06—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B08—CLEANING
  • B08B—CLEANING IN GENERAL; PREVENTION OF FOULING IN GENERAL
  • B08B2203/00—Details of cleaning machines or methods involving the use or presence of liquid or steam
  • B08B2203/007—Heating the liquid
• • 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
  • C11D2111/00—Cleaning compositions characterised by the objects to be cleaned; Cleaning compositions characterised by non-standard cleaning or washing processes
  • C11D2111/10—Objects to be cleaned
  • C11D2111/14—Hard surfaces
  • C11D2111/16—Metals

Definitions

• the invention relates to a composition and a method for removing cryolite-containing deposits of plants or plant parts, which serve for the conversion treatment of metal surfaces.
• a content of accelerating acting additives such as nitrite, chlorate, peroxide or combinations thereof, of anions such as chloride and sulfate to maintain the electroneutrality and optionally layer-refining additives such as hydroxycarboxylic acids, aminocarboxylic acids or condensed phosphates, and complex or simple fluorides is common.
• treatment solutions containing fluoride and possibly nitrate and / or phosphate are also used to treat, in particular, aluminum and zinc.
• treatment solutions containing fluoride and possibly nitrate and / or phosphate are also used to treat, in particular, aluminum and zinc.
• aluminum solutions are common, the titanium and / or zirconium ions, fluoride ions and optionally contain tannin.
• solvents based on sulfuric acid, amidosulfuric acid, hydrochloric acid, nitric acid or sodium hydroxide / complexing agents are used for the chemical removal of deposits in plants or plant components. These are suitable for the removal of crusts consisting of zinc and iron phosphates, as they arise in the phosphating of steel and galvanized steel.
• borate-containing compounds such as boric acid should, however, be avoided as far as possible under environmental and toxicological aspects.
• Boric acid may not be available at all in the near future due to the REACH regulation. At least, however, the availability of boric acid for these reasons will continue to decline over the next few years.
• the object of the invention is to provide a composition and a method for the removal of cryolite-containing deposits of equipment or plant parts, which serve the conversion treatment of metal surfaces, or the disadvantages of the known compositions or methods does not have, and in particular a little time-consuming and economical Cleaning allowed and essentially, in particular completely manages without the use of borate compounds.
• cryolite-containing deposits Furthermore, the time required for complete dissolution / dispersion of the cryolite-containing deposits (dissolution time) and the amount dissolved per solvent amount Amount of cryolite-containing deposits of the combination of mineral acid and borate-containing compound be comparable.
• the object is achieved on the one hand by a method according to the invention for the removal of cryolite-containing deposits of plants or parts of installations in which the plants or plant parts are brought into contact with an aqueous composition which contains a) at least one mineral acid and
• the effect of the at least one dicarboxylic acid in this regard is due to its being an effective complexing agent for Al 3+ and these ions to the solubility equilibrium of cryolite be withdrawn by complexation.
• cryolite-containing deposits solid deposits, ie crusts, which preferably consist of more than 50% by weight and more preferably more than 90% by weight of cryolite (dry weight).
• the term “removal of cryolite-containing deposits” should not only be understood to mean the detachment of said deposits from the corresponding installations or parts of installations but also the dissolution and / or dispersion of at least 90% by weight, in particular the complete dissolution / dispersion of the deposits ,
• an "aqueous composition” is to be understood as meaning that, for the most part, ie more than 50% by weight, contains water as the solvent or dispersion medium.
• the aqueous composition is a solution, more preferably a solution containing only water as the solvent.
• the fact that “no borate-containing compounds have been added to the composition” is not intended to exclude that the composition may contain a negligible proportion of borate-containing compounds, which are then due to contamination of the raw materials used.
• borate-containing compounds is meant in particular borax and boric acid.
• the "normal concentration" of an acid is equivalent to the molar concentration of the acid-releasable protons.
• sulfuric acid for example, two protons are released per acid molecule. Therefore, a sulfuric acid having a molar concentration of 1 mol / l has a normal concentration of 2 mol / l.
• the at least one dicarboxylic acid may also have been added to the solution as salt, ie as dicarboxylate or monohydrogendicarboxylate, of the aqueous composition.
• the plants or plant parts are brought into contact with an aqueous composition which contains a) at least one mineral acid having a normal concentration (total) in the range from 1.0 to 10 mol / l and
• the at least one mineral acid in a normal concentration is preferably in the range from 2.0 to 8.0 mol / l, particularly preferably from 3.0 to 6.0 mol / l and very particularly preferably from 3.5 to 4 , 5 mol / l before, while the at least one dicarboxylic acid in a total concentration in the range of 0.07 to 1, 5 mol / l, more preferably from 0.35 to 1, 5 mmol / l, particularly preferably from 0.35 to 1, 0 mol / l and most preferably from 0.5 to 0.8 mol / l is present.
• the aqueous composition contains the at least one mineral acid and the at least one dicarboxylic acid in a molar ratio ranging from 2.4: 1 to 60: 1, more preferably from 2.6: 1 to 60: 1, more preferably from 2.6 : 1 to 12: 1, more preferably from 4.0: 1 to 12: 1 and most preferably from 5.0: 1 to 8.0: 1 (normal concentration (total) of the at least one mineral acid in mol / l based on the total concentration of the at least one dicarboxylic acid in mol / l).
• aqueous composition containing as the at least one mineral acid hydrochloric acid, sulfuric acid and / or nitric acid.
• the at least one mineral acid is very particularly preferably sulfuric acid.
• Sulfuric acid is considered in terms of performance and its functionality is advantageous over hydrochloric acid and nitric acid.
• hydrochloric acid there is the problem that the deposits containing cryolite can only be dissolved slowly, since the system can not be heated for the purpose of accelerating the dissolution process. The resulting vapors would otherwise corrode the system.
• nitric acid there is a risk that nitrous gases may be produced by reaction with phosphating residues.
• Dicarboxylic acids with x> 3 - as already adipic acid with x 4 -, however, have too low solubility in the aqueous medium and thus can no longer function as complexing agents for Al 3+ .
• the aqueous composition advantageously additionally contains at least one nonionic surfactant. This facilitates the wetting of the cryolite-containing deposits with the aqueous composition.
• the at least one nonionic surfactant is selected from the group consisting of ethoxylated Fettalkoholpolyglykolethern.
• the aqueous composition may additionally contain at least one corrosion inhibitor in order to protect the systems or plant components against corrosion during contact with the aqueous composition.
• the at least one corrosion inhibitor preferably comprises at least one compound selected from the group consisting of urea derivatives, diols and alkoxylated diols.
• the at least one corrosion inhibitor is N, N'-diethylthiourea or a mixture of N, N'-di (o-tolyl) thiourea, N, N'-dibutylthiourea and hexamethylenetetraamine.
• the at least one corrosion inhibitor is a mixture of a compound of the formula I. wherein R 1 and R 2 are both H, and a compound of formula I wherein R 1 and R 2 are each independently an HO- (CH 2 ) w group with w> 2, preferably both HO- (CH 2 ) 2 group, wherein in each of the two compounds of formula I x and y are each independently 1 to 4.
• a mixture is toxicologically less harmful and less harmful to the environment than the aforementioned urea derivatives.
• the method of the type mentioned above according to the invention is designed in such a way that the plants or plant parts in contact with an aqueous composition containing a) sulfuric acid having a normal concentration (total) in the range of 1 , 0 to 10 mol / l and
• oxalic acid having a total concentration in the range of 0.07 to 1.7 mol / l, wherein no borate-containing compounds were added to the composition.
• the sulfuric acid is preferably present in a normal concentration (overall) in the range from 2.0 to 8.0 mol / l, particularly preferably from 3.0 to 6.0 mol / l and very particularly preferably from 3.5 to 4, 5 mol / l before, while the oxalic acid in a total concentration in the range of 0.07 to 1, 5 mol / l, more preferably from 0.35 to 1, 5 mol / l, particularly preferably from 0.35 to 1, 0th mol / l and very particularly preferably from 0.5 to 0.8 mol / l is present.
• the aqueous composition contains the sulfuric acid and the oxalic acid in a molar ratio ranging from 2.4: 1 to 60: 1, more preferably from 2.6: 1 to 60: 1, further preferably from 2.6: 1 to 12 : 1, more preferably from 4.0: 1 to 12: 1 and most preferably from 5.0: 1 to 8.0: 1 (normal concentration (total) of sulfuric acid in mol / l based on the total concentration of oxalic acid in mol / l).
• the plants or plant parts are brought into contact with an aqueous composition which additionally contains nitrate. Due to the presence of nitrate in a sulfuric acid aqueous composition, their passivation is guaranteed in plants or plant components made of stainless steels.
• the plants to be liberated from cryolite-containing deposits can be, for example, spray-phosphating plants or dipping-phosphating plants.
• a plant to be liberated from deposits containing cryolite is preferably brought into contact with the aqueous composition by introducing the latter into the plant up to a filling level such that all plant components containing cryolite-containing deposits are covered with the aqueous composition.
• affected plant components can also be disassembled and placed in an appropriate treatment bath with the aqueous composition, so that all plant components are covered with the aqueous composition.
• aqueous composition is stirred while it is in contact with the corresponding system or with the corresponding system components.
• the aqueous composition can also be circulated particularly advantageously through the system - basins, pipes, nozzles, etc.
• the temperature at which the aqueous composition is used can in principle be between room temperature and about 95 ° C. However, particularly advantageous is a temperature in the range of 40 to 80 ° C, in particular from 50 to 70 ° C, since the dissolution of the cryolite-containing deposits takes place particularly quickly, but without having to take too high an energy consumption into account.
• the desired temperature can be adjusted, for example, by heating the corresponding system or the corresponding treatment bath.
• the time to removal in particular the time to complete dissolution / dispersion (dissolution time) of all cryolite-containing deposits, in the case of circulation of the aqueous composition through the plant, is preferably between 2 and 6 hours.
• the amount of cryolite-containing deposits dissolved per 100 g of the aqueous composition is preferably at least 4 g, more preferably at least 5 g.
• the composition / process according to the invention is also particularly suitable for those made of plastic.
• an aqueous composition for removing cryolite-containing deposits of installations or parts of installations which serve for the conversion treatment of metal surfaces which comprise a) at least one mineral acid and
• the present invention additionally relates to a concentrate from which an aqueous composition according to the invention can be obtained by dilution with a suitable solvent and / or dispersion medium, preferably with water.
• composition (s) of the invention will be further illustrated by the following examples, which are not intended to be limiting.
• the deposits thus consist of about 95 wt .-% of cryolite (NasAIFe).
• the dissolved amount is larger by a factor of 4 to 6, which results in a considerable saving in solvent.
• the amount dissolved using the process according to the invention is comparable to that dissolved with the combination of sulfuric acid / boric acid.
• Adipic acid is not soluble in 20% sulfuric acid and thus can not function as a complexing agent for Al 3+ . Consequently, the same results occur as with 20% sulfuric acid alone.
• the soluble crust quantity is consequently also significantly lower than in the combination sulfuric acid / boric acid.
• Glutaric acid is soluble in 20% sulfuric acid - although the dissolution process can take up to 30 minutes.
• the soluble crust quantity here is comparable to the combination of sulfuric acid / boric acid.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• General Chemical & Material Sciences (AREA)
• Mechanical Engineering (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Inorganic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Emergency Medicine (AREA)
• Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
• Detergent Compositions (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Chemical Treatment Of Metals (AREA)

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Publications (1)

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• 2018
  • 2018-12-07 CN CN201880076195.4A patent/CN111417744B/zh active Active
  • 2018-12-07 US US16/769,966 patent/US11434573B2/en active Active
  • 2018-12-07 BR BR112020009513-3A patent/BR112020009513A2/pt unknown
  • 2018-12-07 KR KR1020207016464A patent/KR102655537B1/ko active IP Right Grant
  • 2018-12-07 JP JP2020532630A patent/JP7394761B2/ja active Active
  • 2018-12-07 EP EP18812176.8A patent/EP3724371A1/de active Pending
  • 2018-12-07 WO PCT/EP2018/084005 patent/WO2019115395A1/de unknown
  • 2018-12-07 MX MX2020006184A patent/MX2020006184A/es unknown

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