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
  • 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

Definitions

• the field of the invention is that of aqueous liquids which can be used as heat transfer fluids for cooling circuits, for example the cooling circuits of internal combustion engines, the corrosivity of which must be remedied.
• Water and aqueous solutions are very widely used as cooling fluids in circuits constructed of various metals, copper, steel, aluminum, cast iron and their alloys, which they attack as soon as corrosion conditions are found.
• the first consequence of corrosion is the loss of material from the walls of the circuits and their perforation. Added to this is the formation of corrosion products, the deposits of which disturb the heat transfers between the fluid and the walls of the circuit, and cause overheating in the hot walls with significant risks of rupture of sensitive mechanical parts.
• the phosphates precipitate in contact with hard water, and therefore their concentration and their activity decreases (depletion), which we can fight against, but at the cost of an increase in the cost of protection, by using certain additives (JP -A-62205183); these phosphates are also harmful to the environment (eutrophication of water). Amines when combined with nitrites generate the risk of formation of nitrosamines, highly toxic products. Releases of fluids containing boron derivatives or molybdates are also harmful and require treatment before being returned to the environment. We therefore turned resolutely to other organic inhibitors, which has given rise to numerous publications and numerous patents, including for example:
• compositions of the present invention provide an answer to this problem which is practically expressed in their compliance with the requirements of the so-called "cavitation” test at the same time as those of the conventional tests for evaluating the hot inhibitory efficacy vis-à-vis - screws of different metals in an antifreeze liquid.
• the CEC C-05X-95 "cavitation" test is one which provides an evaluation of the performance of an inhibiting composition with regard to the corrosion of steel and aluminum by cavitation of a possibly antifreeze fluid. circulating in a loop under standardized conditions of flow, temperature and pressure. These tests are described in the examples.
• the present invention is that of a method for inhibiting multimetal corrosion by heat transfer fluids, whether or not these fluids contain an organic compound lowering the freezing point, which consists in introducing into said fluids 3 to 6% by weight , and preferably 3.8 to 5%, of an organic inhibitor system consisting of:
• (II) 40 to 70% by weight of at least one saturated carboxylic acid taken from the group comprising saturated monocarboxylic acids with 5-16 carbon atoms and saturated dicarboxylic acids with 4-12 carbon atoms, or a salt thereof alkali or amine or alkanolamine metal of these acids; - (III) 20 to 40% by weight of a tricarboxylic derivative of 1,3,5-triazine corresponding to the formula: NHR. -NOT. NHR
• R is a carboxyalkyl group with 2-6 carbon atoms, or an alkali metal or amine or alkanolamine salt of this derivative - (IV) 1 to 5% by weight of an azole derivative taken from the group made up of:
• R T is a hydrogen atom or a methyl radical
• R 2 is a hydrogen atom or a mercapto radical
• R 3 is a hydrogen atom or a radical of formula
• R 4 and R 5 identical or different, representing a 2-ethylhexyl or hydroxyalkyl radical, in particular an ethanol residue.
• the weight ratio of the constituents I and II (l / ll) will be between 5 and 15 and, preferably, between 8 and 12, and the weight ratio of the constituents I and II on the one hand and III (I + ll / lll) will be between 1.5 and 3 and, preferably, between 1.9 and 2.2.
• C 5 -C 10 acids are preferred, in particular n-hexanoic acid, heptanoic acid, n-octanoic acid and nonanoic acid;
• C 4 -C ⁇ 0 acids are preferred, in particular suberic acid, azelaic acid and sebacic acid.
• undecylenic acid is preferred.
• the preferred 1,3,5 triazine tricarboxylic derivative is the compound of formula:
• RN 80584-91 -4 or its triethanolamine salt.
• the inhibitor system according to the invention can be used in aqueous fluids with or without antifreeze for cooling circuits and in particular for cooling circuits of internal combustion engines. It can be implemented by introducing the various components of the inhibitor system directly into the transfer fluid. It is more convenient to use stock solutions which are aqueous solutions comprising from 10 to 60% by weight of the inhibitor system constituted by the components (I), (II), (III) and (IV) as described more high, and whose pH will be adjusted by neutralization, for example with sodium hydroxide in order to dissolve all of the components and so that the pH of the transfer fluid will be in the range 7-9, preferably 7.5- 8.5. These aqueous stock solutions are compositions of the invention. If it is desired to obtain both protection of the circuits against corrosion and freezing, use will be made of inhibiting anti-freeze compositions, also objects of the present invention, consisting of: 0.1 to 10% by weight of the composition inhibitor described above;
• a hydroalcoholic solution having a freezing point below 0 ° C, preferably between -10 and - 40 ° C, the alcohol being taken from the group consisting of methanol, l ethanol, 2-propanol, glycerol, ethylene glycol, diethylene glycol, propylene glycol, 1-methoxy-2-propanol, methyl-, ethyl-, propyl-, butyl ethers of ethylene glycol. Ethylene glycol is preferred.
• the inhibitor system according to the invention provides protection against multimetal corrosion under cavitation corrosion conditions (high temperature, high pressure), a fortiori under milder aggressiveness conditions.
• the inhibitor system of the invention can be used in wide ranges of applications, using media of ferrous iron, cast iron, copper copper and aluminum in particular. We can cite surface treatment, metalworking, paint stripping, lubrication.
• Hot plate test (ASTM D 4340: "Corrosion of cast aluminum alloys in Engine Coolants under Heat-rejecting Conditions"), by which follows the variations in weight of a cast aluminum sample simulating a piston, heated to 135 ° C, for 168 hours (7 days) and subjected to a pressure of 193 kPa in a corrosive solution (0.165 g / l of NaCl ) containing 25% antifreeze; - c) Cavitation test (CEC C-05X-95), by which we measure the mass variation of test bodies made up of cast iron and aluminum discs subjected to the action of flow in loop of a corrosive solution according to ASTM D 1384 (Na 2 S0 4 : 148 mg
• the tests take into account three types of inhibitors: i) conventional mineral compositions based on nitrites, borax or sodium molybdate, ii) organic or mixed compositions of the prior art comprising sebacic acid, iii ) compositions according to the invention.
• the inhibitor components were dissolved in ethylene glycol.
• the pH of the concentrated solution was adjusted between 7 and 8 by adding sodium hydroxide.
• the alkaline reserve (RA) of these compositions expressed in milliliters of 0.1N hydrochloric acid is determined according to standard ASTM D 1121-93.
• These concentrated solutions constitute antifreezes. Coolants are obtained by dilution to 50% with deionized water.
• the test solution consists of a corrosive solution to which this coolant has been added, at a rate of 33% by volume if the ASTM D 1384 standard is applied, 25% by volume for the ASTM D 4340 standard. , 20% by volume for the CEC C-05X-95 standard.
• compositions To prepare the exemplified compositions, the following were used: - as monocarboxylic acid of type (I) heptanoic acid (C 7 ), - as type (II) monocarboxylic acid undecylenic acid
• compositions V9 and V10 being preferred compositions according to the invention; the compositions V 2 , V 3 and V 6 emerging from the invention.
• the ASTM D4340 hot plate test is passed if the weight loss is less than 1 mg / cm / week.
• the CEC C-05X-95 test is considered accepted if the weight variation is between -50 and +10 mg for aluminum and between -10 and +5 mg for cast iron. TABLE 1
• organic (O) or organic-mineral (M) compositions with diacids (adipic (H 2 C 6 ) and sebacic (H 2 C ⁇ 0 )), octanoic acid (C 8 ), sodium molybdate (Molyb.) , sodium nitrite (Nitrite) and tolyltriazole (TTZ) containing (in% by weight):
• composition 03 has interesting performances except however in the test ASTM D 1384 for cast iron where it causes weight gain (instead of loss). This weight gain is a contraindication for a potential blockage of the circuits.
• the use dose of these products is generally between 0.01 and 0.03% by weight relative to the total of the formulation of stock solutions.
• a product well suited to the formulations is 1 - hydroxyethane-1, 1 diphosphonic acid and in particular the commercial product
• DEQUEST 2010 from SOLUTIA This product may exhibit a certain activity with respect to corrosion tests which may require an adjustment of the overall composition according to the invention.

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

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Citations (7)

• 1999
  • 1999-06-28 FR FR9908214A patent/FR2795432B1/fr not_active Expired - Fee Related
• 2000
  • 2000-06-23 WO PCT/FR2000/001760 patent/WO2001000902A1/fr active IP Right Grant
  • 2000-06-23 PL PL00352778A patent/PL352778A1/xx unknown
  • 2000-06-23 BR BR0011906-7A patent/BR0011906A/pt not_active IP Right Cessation
  • 2000-06-23 EP EP00949557A patent/EP1192296A1/fr not_active Withdrawn
  • 2000-06-23 CZ CZ20014588A patent/CZ20014588A3/cs unknown
  • 2000-06-23 CA CA002377776A patent/CA2377776A1/fr not_active Abandoned
  • 2000-06-23 MX MXPA01013315A patent/MXPA01013315A/es unknown
  • 2000-06-23 AU AU62877/00A patent/AU6287700A/en not_active Abandoned
  • 2000-06-23 CN CN00812217A patent/CN1371431A/zh active Pending
  • 2000-06-23 KR KR1020017016814A patent/KR20020026889A/ko not_active Abandoned

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