Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M129/00—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing oxygen
  • C10M129/02—Lubricating compositions characterised by the additive being an organic non-macromolecular compound containing oxygen having a carbon chain of less than 30 atoms
  • C10M129/68—Esters
  • C10M129/76—Esters containing free hydroxy or carboxyl groups
• • 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
• • 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
  • C23F11/12—Oxygen-containing compounds
  • C23F11/124—Carboxylic acids
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2201/00—Inorganic compounds or elements as ingredients in lubricant compositions
  • C10M2201/02—Water
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
  • C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
  • C10M2207/28—Esters
  • C10M2207/287—Partial esters
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
  • C10N2030/00—Specified physical or chemical properties which is improved by the additive characterising the lubricating composition, e.g. multifunctional additives
  • C10N2030/12—Inhibition of corrosion, e.g. anti-rust agents or anti-corrosives

Definitions

• the invention relates to dicarboxylic acid mono- (2-hydroxydodecyl) esters, their salts and their use as a corrosion inhibitor in aqueous systems.
• Water-bearing systems such as steam generation systems, heating systems, cooling water circuits and closed water supply systems are permanently exposed to the corrosive attack of the water circulating in them, which is primarily directed against the base materials of the respective systems, e.g. steel, brass, aluminum, zinc or galvanized steel.
• the risk of corrosion is further increased by the fact that in such systems there are usually elevated temperatures and the circulating water contains constituents which also chemically promote the corrosive attack on the respective materials. Chemicals that prevent corrosion or prevent it completely have therefore long been added to the waters circulating in the systems mentioned as anti-corrosion agents. This has proven particularly useful in this context hang the use of phosphorus-containing compounds, for example phosphonic acids or inorganic phosphates, which are optionally combined with zinc salts. The effectiveness of these combinations has so far been entirely satisfactory.
• Zinc salts are generally known to be extremely toxic to fish, which is why these types of water must never be allowed to get into the wastewater.
• self-cleaning power of natural water is significantly inhibited even at zinc concentrations above 0.1 ppm.
• the use of combinations of zinc salts with phosphonic acids or phosphates also generally leads to increased silting of the process water circulation system due to the precipitation of zinc hydroxide at higher pH values (pH greater than 8.0).
• the object of the present invention was to provide corrosion inhibitors for aqueous systems which are effective, essentially phosphorus- and zinc-free, even at low concentrations, which are easily accessible in terms of production technology and which permanently or completely prevent the corrosion of numerous materials used in plant construction.
• the compounds used should be environmentally neutral and meet the legal requirements applicable in this context, particularly with regard to their toxicity.
• the invention therefore relates to dicarboxylic acid mono- (2-hydroxydodecyl) esters of the general formula (I) and their salts of the general formula (II) in which A for the residues - (CH2) 2-, - (CH2) 3-, and M represents an alkali metal or ammonium.
• the general formulas (I) and (II) defined above thus comprise the following compounds: succinic acid mono- (2-hydroxydodecyl) ester, glutar acid mono- (2-hydroxydodecyl) esters, itaconic acid mono- (2-hydroxydodecyl) esters, phthalic acid mono- (2-hydroxydodecyl) esters or their salts, preferably their sodium, potassium or ammonium salts, and in particular their sodium salts.
• the invention also relates to the use of dicarboxylic acid mono- (2-hydroxydodecyl) esters (I) and / or their salts (II) in concentrations of 1 to 100 ppm as corrosion inhibitors in aqueous systems, if appropriate in the presence of further stone protection and / or dispersants and / or non-ferrous metal inhibitors and / or microbicides.
• the invention also relates to the use of dicarboxylic acid mono- (2-hydroxydodecyl) esters (I) and / or their water-soluble salts (II) in combination with one or more complexing agents from the group consisting of ethylenediaminetetraacetic acid, nitrilotriacetic acid, citric acid, phosphoric acid esters of ethoxylated sugars and phosphonic acid or the water-soluble salts of these acids, in particular the sodium salts, optionally in the presence of further, known stone protection and / or dispersants and / or non-ferrous metal inhibitors and / or microbicides as corrosion inhibitors in aqueous systems, the concentration of the mixture of (I) and / or (II) and the complexing agents in aqueous solution in the range from 1 to 100 ppm and the ratio of (I) and / or (II) to the complexing agents in the range between 5: 1 and 1: 5.
• one or more complexing agents from the group
• the high effectiveness of the compounds mentioned as corrosion inhibitors is all the more surprising as Dicarboxylic acid mono- (2-hydroxyalkyl) esters, in which the ester alkyl groups have less than 12 or more than 12 C atoms, and dicarboxylic acid monoalkyl esters, which have no hydroxyl group in the ester alkyl group, have an insignificant or no corrosion-inhibiting action in process water.
• Dicarboxylic acid mono- (2-hydroxyalkyl) esters in which the ester alkyl groups have less than 12 or more than 12 C atoms
• dicarboxylic acid monoalkyl esters which have no hydroxyl group in the ester alkyl group, have an insignificant or no corrosion-inhibiting action in process water.
• Corrosion inhibitors according to the invention are primarily dicarboxylic acid mono- (2-hydroxydodecyl) esters of the formula (I) and their water-soluble salts of the general formula (II)
• A represents the radicals - (CH2) 2-, - (CH2) 3-, and M for an alkali metal or ammonium, preferably for sodium, potassium or ammonium.
• the resulting Salts (II) have good water solubility without exception.
• the corrosion inhibitors to be used according to the invention are therefore the following compounds: Succinic acid mono- (2-hydroxydodecyl) esters, glutaric acid mono- (2-hydroxydodecyl) esters, itaconic acid mono- (2-hydroxydodecyl) esters, phthalic acid mono- (2-hydroxydodecyl) esters or their salts defined above.
• Succinic acid mono- (2-hydroxydodecyl) esters glutaric acid mono- (2-hydroxydodecyl) esters
• itaconic acid mono- (2-hydroxydodecyl) esters phthalic acid mono- (2-hydroxydodecyl) esters or their salts defined above.
• phthalic acid mono- (2-hydroxydodecyl) esters or their salts are preferred.
• the half esters (I) formed by esterification between the acid anhydride or the dicarboxylic acid and the alcoholic component can subsequently be neutralized by reaction with a base M-OH, salts (II) being formed in accordance with the above reaction scheme.
• the dicarboxylic acid mono- (2-hydroxydodecyl) esters (I) and their salts (II), in which A and M have the meanings given above, are used individually or in any mixtures with one another as corrosion inhibitors.
• the high, corrosion-inhibiting action of the esters (I) alone is remarkable and particularly advantageous for the use according to the invention, without any further addition.
• the concentration of the dicarboxylic acid mono- (2-hydroxydodecyl) ester (I) and / or its salts (II) is in the range from 1 to 100 g / m3, i.e. in the range of 1 to 100 ppm.
• a preferred concentration range is 10 to 50 ppm of the compounds (I) and / or (II) mentioned.
• the compounds (I) and / or (II) are used according to the invention as a corrosion inhibitor for metals
• aqueous systems such as are found in water-carrying systems such as steam generating systems, heating systems, cooling water circuits and water supply systems.
• the compounds mentioned can preferably be used in process water systems.
• polyacrylates and / or copolymers of acrylic acid and / or methacrylic acid and / or their derivatives with an average molecular weight of 500 to 4000 and / or ethylene oxide-propylene oxide block copolymers with an average molecular weight of 500 to 3000 have proven to be stone protection and / or dispersants and an ethylene oxide to propylene oxide ratio of 10:90 to 30:70.
• stone protection and dispersing agents are used in combination with dicarboxylic acid mono- (2-hydroxydodecyl) esters (I) and / or their salts (II) in amounts of 1 to 50 g / m3 (1 to 50 ppm), preferably in amounts of 3 to 10 ppm.
• the corrosion inhibitors (I) and / or (II) are used according to the invention, it may be advantageous to provide inhibitors for non-ferrous metals as further additives known per se for this purpose.
• dicarboxylic acid mono- (2-hydroxydodecyl) esters and / or their water-soluble salts according to the invention 3-heptyl-5-amino-1,2,4-triazole, benzimidazole, benzotriazole and / or tolyltriazole are preferably dissolved in the process water as non-ferrous metal inhibitors.
• the amount of non-ferrous metal inhibitors is in the range from 0.1 to 5 g / m3 (0.1 to 5 ppm).
• microbicidal or biocidal substances may also be advantageous to add microbicidal or biocidal substances to the industrial water in amounts of 1 to 100 g / m3 (1 to 100 ppm).
• such substances are in particular glutaraldehyde, glyoxal or alkyloligoamides, preferably in the form of a reaction product of dodecylpropylenediamine and ⁇ -caprolactam in a molar ratio of 1: 2.
• the dicarboxylic acid mono- (2-hydroxydodecyl) esters (I) or their water-soluble salts (II) used according to the invention as corrosion inhibitors for metals have the advantage over comparable compounds used as corrosion inhibitors or with regard to the chemical structure that they have completely different corrosion-inhibiting substances, for example in the way described above, are technically easy to manufacture and already at low concentrations in the aqueous in question Systems have an extremely high corrosion-inhibiting effect. This effect is largely independent of the pH. In addition, they have no detrimental, in particular no toxic, effect and can therefore be used without hesitation in water that is ultimately released into the environment from the systems mentioned. In comparison to phosphorus-containing corrosion-inhibiting agents, they also do not lead to eutrophication of the water.
• esters of the formula (I) and / or their salts corresponds to the general formula (II), preferably the sodium salts, a particularly preferred and advantageous embodiment of the present invention, which is also significantly better than that of conventional complexing agents in terms of the corrosion-inhibiting activity.
• the combination of for Corrosion inhibiting agents used complexing agents with the esters (I) of the present invention and / or their salts (II) leads to a significant improvement in corrosion protection.
• a further preferred embodiment within the meaning of the present invention should therefore be considered to use dicarboxylic acid mono- (2-hydroxydodecyl) ester (I) and / or its water-soluble salts (II) in combination with one or more complexing agents for inhibiting corrosion in aqueous systems.
• the esters (I) and their water-soluble salts (II), of which the sodium salt is particularly preferred over the other alkali metal salts or the ammonium salt, can be used individually or in any mixtures with one another.
• Complexing agents from the group consisting of ethylenediaminetetraacetic acid, nitrilotriacetic acid, citric acid, phosphoric acid esters of ethoxylated sugars and phosphonic acid or the water-soluble salts of these acids, in particular the sodium salts, are suitable for such preferred combinations.
• phosphoric acid esters of ethoxylated sugars esters of such sugars are suitable which have a degree of ethoxylation of 1 to 10, preferably 1 to 5.
• the sugars are selected from the group of sorbitol, mannitol, glucose and mixtures of two or three of these sugars in any proportion with one another.
• phosphonic acids suitable for the purpose of complex formation can be used as phosphonic acids the, where phosphonic acids from the group 1-hydroxyethane-1,1-diphosphonic acid, aminotris- (methylenephosphonic acid) and 2-phosphonobutane-1.2.4-tricarboxylic acid and the water-soluble salts of such phosphonic acids are suitable. These can also be used individually or in any mixtures with one another.
• the concentration of the combination of mono- (2-hydroxydodecyl) dicarboxylic acid (I) or its water-soluble salts (II) on the one hand and one or more complexing agents from the above-mentioned group on the other hand in the aqueous solution is in the range from 1 to 100 ppm, preferably in the range from 2 to 60 ppm.
• the ratio of the components ester (I) and / or their salts (II) to complexing agents is in the range between 5: 1 and 1: 5, a range from 2: 1 to 1: 2 being particularly preferred.
• the corrosion-inhibiting effect even when using such combinations, is largely independent of the pH, since the acid form of the esters, that is to say the compound (I.), Immediately changes in the acidic pH range, for example at a pH of 6.5 ), forms during alkaline pH values, for example at a pH of 8.2, the alkali metal or ammonium salts of the esters, that is to say the compounds (II), are present.
• the combinations according to the invention of compounds (I) and / or (II) with one or more of the complexing agents mentioned can also be mixed with other additives customary in such systems without difficulty, with the result that, together with these, an additionally improved corrosion protection trains. Examples of such additives are stone protection agents and / or dispersants, non-ferrous metal inhibitors or biocides from the groups specified above.
• the blank value was determined on sheets of the same quality after treatment with an aqueous solution without the inhibitor according to the invention.
• test water used as the corrosive medium had the following analytical data: 8 ° dH (calcium hardness); 2 ° dH (magnesium hardness); 1 ° dH (carbonate hardness) and 500 ppm Cl ⁇ .
• Table 1 below shows the results of the corrosion protection tests when using dicarboxylic acid mono- (2-hydroxydodecyl) esters (DHDE) or their sodium salts.
• DHDE dicarboxylic acid mono- (2-hydroxydodecyl) esters
• dicarboxylic acid mono- (2-hydroxydodecyl) esters (I), or their Na salts as corrosion inhibitors can provide significantly better corrosion protection in both weakly acidic and weakly basic environments than with the structurally similar compounds to DHDE - see experiments a to g.
• the comparison compounds a to f are corresponding dicarboxylic acid monoesters with shorter or longer carbon chains in the ester alkyl groups; in the case of the comparative compound g, the ester alkyl group - with a chain length of 12 carbon atoms - has no hydroxyl group.
• the corrosion inhibitors known from the prior art - see experiment h to k - better or comparable values are obtained, but when using the DHDE no phosphorus and no zinc get into the waste water and no precipitation occurs.
• Example 2 Analogously to the procedure described in Example 1, a corresponding number of test sheets were treated in an aqueous solution which contained a combination of DHDE (I) or its sodium salt (II) and a complexing agent, which is mentioned in Table 3. The sheets were treated as described in Example 1 and the corrosion protection value of the combination used according to the invention, based on a blank value, was determined in accordance with the formula given in Example 1.
• Example 2 Analogously to Example 2, in comparison to the combination of DHDE or its sodium salts and complexing agents, further corrosion inhibitors known per se, in some cases together with zinc salts, were tested with regard to their corrosion-inhibiting behavior. The results are shown in Table 4 below.

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• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
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• Metallurgy (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 1986
  • 1986-06-12 DE DE19863619804 patent/DE3619804A1/de not_active Withdrawn
• 1987
  • 1987-06-04 EP EP87108076A patent/EP0249148A3/fr not_active Withdrawn
  • 1987-06-12 JP JP62147807A patent/JPS62298554A/ja active Pending
  • 1987-06-12 US US07/061,856 patent/US4902443A/en not_active Expired - Fee Related

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