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
  • 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
  • C23F11/16—Sulfur-containing compounds
• • 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 invention relates to the use of water-soluble salts of certain aminotriazine polycarboxylic acids and half esters thereof as corrosion inhibitors for use in aqueous systems, for example in aqueous surface coating compositions, such as emulsion paints or aqueous powder coating systems, or in aqueous cooling systems, but in particular in lubricant and cooling systems in metalworking processes.
• aqueous surface coating compositions such as emulsion paints or aqueous powder coating systems
• aqueous cooling systems but in particular in lubricant and cooling systems in metalworking processes.
• the invention relates to an aqueous system containing, as a corrosion inhibitor, a water-soluble salt of an aminotriazine polycarboxylic acid or a partial ester (half ester) of this acid of the general formula I.
• the group -NR R a straight-chain or branched C 1 -C 4 alkyl group, a mononuclear C 1 -C 10 aryl group optionally substituted by one or more water-solubilizing groups
• the rest or a residue of the formula represents in which X denotes the group -CH 2 - or -0-, in which R 1 and R 2 are identical or different and denote hydrogen, a group -CHR 4 SR 3 or a group -CHR 4 SR 5 COOQ, where Q is Hydrogen or a straight-chain or branched C 1 -C 8 -alkyl group, R 3 for a straight-chain or branched C 1 -C 12 -alkyl group, R 4 for hydrogen, a
• R represents a straight-chain or branched alkyl group, it is preferably methyl. If R represents an aryl group which is substituted by water-solubilizing groups, the latter group is, for example, -OH or -COOH.
• the system according to the invention preferably contains those compounds of the formula I in which R is -NR 1 R 2 and R 1 and R 2 are the group -CHR 4 SR 5 COOQ, where R 4 is hydrogen, R 5 is a methylene or ethylene group and Q is hydrogen.
• Metalworking is understood to be the workshop or factory processing of metals, e.g. Drilling, rolling, milling, turning, cutting, sawing, grinding and thread cutting as well as non-cutting deformation, drawing and stretching.
• the salt of the compound of formula I is preferably an alkali salt, in particular a K or Na salt or else an amine salt, in particular a triethanolamine salt.
• the water-soluble amine which forms the salt with the compounds of the formula I can be a mono-, di- or trialkylamine having up to 8 carbon atoms, such as, for example, methylamine, ethylamine, propylamine, butylamine, pentylamine, hexylamine, heptylamine, octylamine , Dimethylamine, diethylamine, dipropylamine, di-n-butylamine, trimethylamine, triethylamine or cycloalkylamine containing up to 6 carbon atoms such as cyclopentylamine, cyclohexylamine, a mono-, di- or trialkanolamine containing 1 to 9 carbon atoms, such as ethanolamine, 2 Hydroxypropylamine, 3-hydroxypropylamine, 4-hydroxybutalamine, 6-hydroxyhexylamine, 8-hydroxyoctylamine, diethanolamine, dipropanolamine, triethanolamine, dimethylamin
• the salts can be prepared by known processes by reacting the acid and the base either in a stoichiometric ratio or in excess of one of the two components.
• the pH of the liquid is preferably 7.5 to 10, in particular 8 to 9.5.
• the pH is expediently adjusted by adding amine, preferably triethanolamine.
• the amount of the compound of formula I which is present in the aqueous system during use is generally 0.005 to 2% by weight, preferably 0.01 to 1% by weight and in particular 0.05 to 1% by weight, based on the total weight of the system.
• the invention further relates to a method for inhibiting metal corrosion in aqueous systems, such as e.g. in a metal working process which is characterized in that the metal is brought into contact with an aqueous system which contains a salt of a compound of the formula I, if appropriate in the presence of an excess of an amine.
• a triethanolamine salt and excess triethanolamine are preferably used.
• the salts of the compounds of the formula I used according to the invention can also be used as corrosion inhibitors in antifreeze and hydraulic fluids which contain water and glycol, and also in aqueous surface coating systems, such as aqueous emulsion paints and aqueous powder coating systems.
• Extreme pressure additives which may be contained in the systems according to the invention are, for example, sulfur and / or phosphorus and / or halogen-containing substances, such as e.g. sulphurized whale oils, sulphurized fats, tritoluolphosphates, chlorinated paraffins or ethoxylated phosphate esters.
• sulfur and / or phosphorus and / or halogen-containing substances such as e.g. sulphurized whale oils, sulphurized fats, tritoluolphosphates, chlorinated paraffins or ethoxylated phosphate esters.
• the acids or the partial esters thereof of the formula I in which R 1 and R 2 are identical or different and denote hydrogen or a group —CHR 4 S R 5 COOQ, where R 4 , R and Q have the meaning given above, can by Reaction of at least 2 gram equivalents (Val) of a mercaptocarboxylic acid of the general formula II with 1 gram equivalent of an optionally alkylated condensation product of an aminotriazine with an aldehyde of Fromel R4CHO, which of the formula III is obtained, where R 6 is a group -NR R, a straight-chain or branched C 1 -C 4 alkyl group or a mononuclear C 6 -C 10 aryl group optionally substituted by a water-solubilizing group and R 7 and R 8 are the same or are different and for hydrogen or a group -CHR 4 -OR 9 , in which R 9 is hydrogen or a straight-chain or branched C 1 -C 8 alkyl group,
• the acids and partial esters of the formula I in which R and R 2 are identical or different and are a group -CHR 4 SR 3 or a group -CHR 4 SR 5 COOQ, where R 3 , R 4 , R 5 and Q are the same as before have given meaning, can by reaction of at least 2 gram equivalents (Val) of a mercaptocarboxylic acid of formula II and 1 to 4 gram equivalents of an alkyl mercaptan of formula IV can be obtained with 1 gram equivalent of the condensation product of formula III.
• reaction can be carried out by mixing the components at room temperature or preferably at elevated temperature, usually at 50 ° to 150 ° C., in the presence or in the absence of suitable solvents.
• Water, methanol, ethanol, dioxane, acetone, acetic acid, benzene or toluene are suitable as solvents.
• an acid catalyst such as sulfuric acid or hydrochloric acid, is added.
• the product obtained is generally a mixture of the acid of the formula I with Q as hydrogen with a small proportion of the ester of the formula I in which Q is an identical alkyl group R 9 , preferably methyl, n-butyl, isobutyl or 2-ethylhexyl.
• R 9 is an identical alkyl group
• This modification of the process can be used as an alternative to the use of an alkylated aminotriazinaldehyde condensation product (for example a compound of the formula III in which at least one of the groups R 7 and R 8 represents a group -CHR 4 -OR 9 in which R 9 means one of the alkyl groups previously indicated). It can also be used if such a condensation product is used to increase the content of ester groups, the residues -OQ and -OR9 being the same or different in the ester groups can.
• an alkylated aminotriazinaldehyde condensation product for example a compound of the formula III in which at least one of the groups R 7 and R 8 represents a group -CHR 4 -OR 9 in which R 9 means one of the alkyl groups previously indicated. It can also be used if such a condensation product is used to increase the content of ester groups, the residues -OQ and -OR9 being the same or different in the ester groups can.
• aminotriazine polycarboxylic acids of the formula I in which at least 3 of the radicals Q are hydrogen, are prepared by known processes using an alcohol of the formula VI in which Q 1 has the meaning given above, esterified.
• ester of the formula IV or alcohol of the formula VI should not be so great in the processes described that the product contains on average less than 2 free carboxyl groups per molecule.
• the reaction is preferably carried out in an aqueous medium in such a way that the acid of the formula II, the ester of the formula V (if used) and the aminotriazine of the formula VII are kept in contact, if appropriate with heating, until they dissolve with salt formation, and then the aldehyde of formula VIII is added. The mixture is then stirred until the reaction is complete.
• the reaction can be carried out at room temperature but preferably at a temperature of 50 ° to 100 ° C.
• the acid of formula II and the ester of formula V can first be mixed with the aldehyde of formula VIII under aqueous or anhydrous conditions and then the aminotriazine of formula VII can be added .
• This reaction can also be carried out at room temperature and elevated temperature.
• the reaction agents are preferably heated to 50 ° to 100 ° C.
• melamine is reacted in the absence of an ester of the formula V with 2 to 6 gram equivalents of formaldehyde and the mercaptocarboxylic acid.
• the Aminotriazinpolycarbon Acid of the formula I in which all of R 4 and Q - is a hydrogen atom groups can also be prepared in such a way that 1 gram equivalent of an aminotriazine of the formula IX with at least 2 gram equivalents of a mercaptocarboxylic acid of the formula II, where R11 is a group -NR 12 R 13 , a straight-chain or branched C 1 -C 4 -alkyl group or optionally by a water-solubilizing group is substituted, 1-ring C 6 -C 10 aryl group and R 12 and R 13 , which are the same or different, represent hydrogen or a group -CH 2 NR 14 R 15 .
• R 14 denotes hydrogen or a straight-chain or branched C 1 -C 4 alkyl group and R 15 denotes such an alkyl group (whereby this alkyl group can be the same or different), or R 14 and R 15 together with the N- Atom to which they are attached, a monovalent, mononuclear heterocyclic radical that contains up to 8 carbon atoms.
• R 12 and R 13 are chosen such that the compound of formula IX contains at least 2 groups -CH 2 NR 14 R 15 .
• reaction is carried out in the absence or in the presence of solvents such as xylene, methanol, ethanol, dioxane, acetone, glacial acetic acid, benzene, toluene or pyridine, with elimination of the amine of formula X
• the reacting substances are heated to temperatures of 100 ° to 200 ° C.
• the aminotriazines of the formula IX used as starting products are prepared by Mannich reaction between a triazine of the formula VII, formaldehyde and a primary or secondary amine of the formula X or a salt of such an amine.
• the nature of the amine used is generally not critical, but because of the economy (formation of undesirable by-products) and to facilitate the cleavage during the reaction with the mercaptocarboxylic acid, R 14 preferably represents a hydrogen atom and R 15 either methyl or ethyl or R 14 and R 15 are both methyl or Ae thyl or R 14 and R 15 together are - (CH 2) 5 or a group - (CH 2) 2 -O- (CH 2) 2 - represents.
• Examples 1 to 29 The tests are carried out to demonstrate the corrosion inhibition capabilities of various concentrations of the triethanolamine salts of the following compounds of the formula I in the presence of excess triethanolamine.
• test method used is a modification of the IP 287 test, which is normally used to demonstrate the corrosion resistance properties of emulsifiable grinding oils diluted with water until damaged (rusting).

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)
• Anti-Oxidant Or Stabilizer Compositions (AREA)
• Lubricants (AREA)

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Citations (4)

• 1981
  • 1981-05-01 EP EP81810168A patent/EP0041039A1/fr not_active Withdrawn
  • 1981-05-08 JP JP7005181A patent/JPS5729583A/ja active Pending

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