Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
  • C09K5/20—Antifreeze additives therefor, e.g. for radiator liquids
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
• • 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
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
  • C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
• • 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
  • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
  • C23F11/00—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent
  • C23F11/08—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids
  • C23F11/10—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in other liquids using organic inhibitors
  • C23F11/14—Nitrogen-containing compounds
  • C23F11/149—Heterocyclic compounds containing nitrogen as hetero atom
• • 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
  • C23G1/061—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors nitrogen-containing compounds

Definitions

• juiced imidazoles as non-ferrous metal corrosion inhibitors and antifreeze concentrates and coolant compositions containing them
• the present invention relates to the use of special juiced imidazoles as corrosion inhibitors in the corrosion protection of non-ferrous metals
• Coolant protection agents for the cooling circuits of internal combustion engines usually contain alkylene glycols, especially ethylene glycol or propylene glycol, as the main component.
• alkylene glycols especially ethylene glycol or propylene glycol
• they are diluted with water and are supposed to provide good heat dissipation in addition to frost protection.
• alkylene glycol / water mixtures are very corrosive at the operating temperatures of internal combustion engines, which is why the various metals and their alloys that occur in the cooling system must be sufficiently in front of the most diverse types of corrosion, e.g. Pitting corrosion, crevice corrosion, erosion or cavitation are protected.
• a large number of chemical individuals are already known in the prior art for use as corrosion inhibitors in such cooling systems.
• the combination of the salt of an aliphatic monobasic C 3 -C 1 6-acid, the salt of a C 5 -C 16 dibasic -Kohlenwasserstoffklare and hydrocarbons stofftriazol as an effective inhibitor formulation in an in EP-B 229 440 (1) liquid-alcoholic freezing point depressant for the protection of Aluminum alloys described before pitting.
• other customary inhibitors such as alkali metal borate, silicate, benzoate, nitrate, nitrite, molybdate and / or a hydrocarbazole can be used.
• Anti-freezing agents especially for the automotive radiator, known what formulation of a combination of the salt of an aliphatic monobasic C5-C 16 acid, a hydrocarbyl triazole and imidazole as an effective inhibitor in a liquid alcoholic Gefrierddlingserniedri ⁇ means comprises. Unsubstituted imidazole and alkyl- and aryl-substituted imidazole are suitable as “imidazole”.
• a weakness of the known inhibitor combinations is that the non-ferrous metal contactor has to be cut back at higher temperatures. For example, lose the hydrocarbon triazoles predominantly used here, e.g. Benzo- and toluotriazole, their effectiveness from approx. 130 ° C.
• the object on which the invention is based was therefore to find substances which increase the protective capacity of conventional inhibitor systems against non-ferrous metals at high temperatures, without having to accept the protective capacity for the other metals, particularly for aluminum alloys.
• hydrocarbon triazoles such as benzo- or toluotriazole are largely replaced by quaternized imidazoles, resulting in a noticeable improvement in the protection for non-ferrous metals, in particular for copper, brass and bronze, under high temperature stress results.
• R 1 and R 3 are independently saturated or unsaturated hydrocarbon radicals having 1 to 12 carbon atoms designated, which may be sub ⁇ stituiert by sauerstoffunktionelle groups or atoms interrupted by nonadjacent oxygen.
• R, R 4 and R 5 independently of one another are hydrogen or saturated or unsaturated hydrocarbon radicals having 1 to 12 carbon atoms, which can be substituted by oxygen-functional groups or interrupted by non-adjacent oxygen atoms, where R 4 and R 5 together with the corresponding imidazole carbon atoms can form a five- or six-membered ring, and
• Suitable oxygen-functional groups for the radicals R 1 to R 5 are, in particular, hydroxyl, carbonyl, carboxyl and C 1 -C 4 -alkoxycarbonyl. Depending on the size of the radical R 1 to R 5 , 1 to 6, in particular 1 to 3, such oxygen-functional groups can occur per radical. Likewise, 1 to 6, in particular 1 to 3, ether oxygen atoms can be present per residue.
• R 1 Ci to C 4 alkyl, C 2 to C 4 alkenyl, C 2 to
• R 2 is hydrogen or C 1 -C 4 -alkyl
• R 3 denotes C ⁇ ⁇ to C 4 alkyl or benzyl
• R 4 and R 5 are hydrogen, C -.- to C 4 alkyl or together a benzanellant and
• X® for a mono-Ci to -C 4 alkyl sulfate anion, for sulfate in half the stoichiometric amount, dihydrogen phosphate (H 2 P0 4 ⁇ ), hydrogen phosphate (HP0 4 2 ⁇ ) in half the stoichiometric amount, phosphate (P0 4 3 ⁇ ) in one third of the stoichiometric amount, nitrate,
• Chloride or bromide is available.
• Particularly preferred quaternized imidazoles I are 1-methylimidazole, 1-ethylimidazole, 1- (ß-hydroxy-) quaternized with benzyl chloride, benzyl bromide, methyl chloride, methyl bromide, ethyl chloride, ethyl bromide, diethyl sulfate or in particular dimethyl sulfate.
• ethyl) imidazole 1, 2-dimethylimidazole, 1-phenylimidazole, benzimidazole and in particular N-vinylimidazole.
• the anions mentioned can also be obtained by customary anion exchange processes on the quaternized system.
• the quaternization with dialkyl sulfates one or two alkyl groups can be transferred, correspondingly resulting as anions R 3 OS0 3 ⁇ or S0 2 ® (in half the stoichiometric amount).
• N-vinylimidazole quaternized with dimethyl sulfate for the present invention.
• the present invention furthermore relates to antifreeze concentrates based on alkylene glycols or their derivatives which contain 0.0005 to 2% by weight, preferably 0.01 to 1% by weight, especially 0.05 to 0.5% by weight. -%, based on the total amount of the concentrate, contain one or more of the quaternized imidazoles I mentioned.
• hydrocarbon triazoles such as benzo- or toluotriazole
• hydrocarbon triazoles which are usually contained in such antifreezes and are unfavorable in terms of their temperature resistance
• hydrocarbon triazoles such as benzo- or toluotriazole
• a preferred embodiment of the present invention relates to antifreeze concentrates according to the invention which additionally contain up to 0.
• a further preferred embodiment of the present invention relates to antifreeze concentrates according to the invention, which additionally 0.001 to 5% by weight, in particular 0.01 to 2% by weight, especially 0.05 to 1% by weight, based on the total amount of the concentrate, non-quaternized imidazole and / or at least one non-quaternized alkyl or aryl-substituted imidazole, for example an 1- (C 1 -C 4 -alkyl) imidazole or 1-phenyl-imidazole.
• the antifreeze concentrates according to the invention can furthermore additionally contain all other customary inhibitor components for radiator protection formulations. The following are particularly worth mentioning:
• alkali metal borates e.g. Sodium tetraborate (borax), and / or alkali metal phosphates, e.g. Disodium hydrogen phosphate or trisodium phosphate;
• aromatic monocarboxylic acids up to 5% by weight, in particular 0.05 to 4% by weight, based on the total amount of the concentrate, of at least one aliphatic or aromatic monocarboxylic acid having 3 to 16 carbon atoms, in particular 5 to 12 carbon atoms, where aromatic monocarboxylic acids must have at least 7 carbon atoms, in the form of their alkali metal, ammonium or amine salts, for example the sodium or potassium salts of pentanoic acid, hexanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, benzoic acid or methylbenzoic acid;
• alkali metal silicates alkali metal nitrites, alkali metal nitrates, magnesium nitrate and alkali metal molybdates in amounts of up to 1% by weight, especially 0.05 to 0.8% by weight, based on the total amount of the concentrate ;
• alkali metal compounds are sodium metasilicate, sodium nitrite, sodium nitrate and sodium molybdate.
• alkali metal silicates are also used, these are expediently stabilized in customary amounts by conventional organosilicophosphonates or organosilicosulfonates.
• hydrocarbazoles can also be used in customary amounts, for example.
• the total corrosion inhibitor package based on the total amount of the concentrate, can make up to 15% by weight, in particular up to 10% by weight, the concentration of individual components being up to 5% by weight.
• the antifreeze concentrates according to the invention can furthermore additionally contain up to 1% by weight, in particular 0.01 to 0.5% by weight, based on the total amount of the concentrate, hard water stabilizers based on polyacrylic acid, polymaleic acid, acrylic acid-maleic acid. Contain copolymers, polyvinylpyrrolidone, polyvinylimidazole, vinylpyrrolidone-vinylimidazole copolymers and / or copolymers of unsaturated carboxylic acids and olefins.
• the pH of the antifreeze concentrates according to the invention is usually in the range from 6 to 11, preferably 7 to 9, in particular 7.1 to 7.3.
• the desired pH is generally set by adding alkali metal hydroxide, ammonia or amines to the formulation; solid sodium and potassium hydroxide and aqueous sodium and potassium hydroxide solutions are particularly suitable for this.
• Aliphatic or aromatic mono- and / or dicarboxylic acids to be used are expediently added as corresponding alkali metal salts in order to be automatically in the desired pH range, but these carboxylic acids can also be added as free acids and then with alkali metal hydroxide , Neutralize ammonia or amines and set the desired pH range.
• Alkylene glycols or their derivatives, in particular propylene glycol and especially ethylene glycol, are suitable as liquid alcohol freezing point depressants, which normally make up the main component (generally at least 80% by weight, in particular at least 90% by weight) of the antifreeze concentrates according to the invention.
• higher glycols and glycol ethers are also possible, e.g. Diethylene glycol, dipropylene glycol and monoethers of glycols such as the methyl, ethyl, propyl and butyl ether of ethylene glycol, propylene glycol, diethylene glycol and dipropylene glycol. Mixtures of the glycol and glycol ether mentioned can also be used.
• the present invention also relates to ready-to-use aqueous coolant compositions with a reduced freezing point, in particular for automotive radiator protection, which comprise water and 10 to 90% by weight, preferably 20 to 60% by weight, of the antifreeze concentrates according to the invention.
• the present invention further relates to a process for treating aqueous liquids which contain a water-soluble freezing point depressant based on alkylene glycols or their derivatives, for reducing the corrosion of non-ferrous metals which is in contact with the aqueous liquids, which is characterized in that a effective amount of one or more quaternized imidazoles I mixed into the aqueous liquids.
• the effective amount for the imidazoles I acting as corrosion inhibitors is normally 0.0005 to 2% by weight, preferably 0.01 to
• Table 1 shows the composition of the inhibitor mixtures used to illustrate the invention in ethylene glycol. These antifreeze concentrates were subjected to the usual corrosion tests in aqueous dilution.
• Imidazole represents the principle of action of the non-ferrous metal protection according to the invention.
• Examples C and D in a direct comparison between 1-methylimidazole and 1-methylimidazole quaternized with dimethyl sulfate (DMS), illustrate the significant difference in material removal for copper and brass.
• DMS dimethyl sulfate
• the good protective effect of the quaternary structure which is at least at the level of the effect of e.g. Benzotriazole, the commonly used hydrocarbon triazole, lies, as the comparative example X shows.
• the quaternized imidazoles also show at least as good a protective effect on non-ferrous metals (here soft solder, steel, gray cast iron and cast aluminum) like benzotriazole.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Combustion & Propulsion (AREA)
• Thermal Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)

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• 1996
  • 1996-02-15 DE DE19605509A patent/DE19605509A1/de not_active Withdrawn
• 1997
  • 1997-02-13 KR KR10-1998-0705461A patent/KR100444649B1/ko not_active Expired - Fee Related
  • 1997-02-13 AT AT97903264T patent/ATE186561T1/de not_active IP Right Cessation
  • 1997-02-13 JP JP52898397A patent/JP4020968B2/ja not_active Expired - Fee Related
  • 1997-02-13 EP EP97903264A patent/EP0880566B1/de not_active Expired - Lifetime
  • 1997-02-13 US US09/125,038 patent/US6045719A/en not_active Expired - Fee Related
  • 1997-02-13 ES ES97903264T patent/ES2140206T3/es not_active Expired - Lifetime
  • 1997-02-13 DE DE59700690T patent/DE59700690D1/de not_active Expired - Fee Related
  • 1997-02-13 WO PCT/EP1997/000648 patent/WO1997030133A1/de not_active Ceased
• 1998
  • 1998-06-08 MX MX9804557A patent/MX9804557A/es unknown

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