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

Definitions

• the invention relates to a melamine-containing Corrosion inhibitors and aqueous systems in which this Corrosion protection agent is used.
• polycarboxylic acids are only slightly soluble in water have, the polycarboxylic acids are used in the form of their water-soluble salts, i.e. they are neutralized before the Use or add to a basic water system. Storage and trading forms are, however, generally the free ones Polycarboxylic acids.
• the free polycarboxylic acids are generally solid substances. During their manufacture, they are usually filtered out isolated from an aqueous phase. The filtered product is usually washed with water and then dried subjected. To the energy required for drying save, one has recently for use in aqueous Systems the moist filter cake, which is about 50% water contains, offered as a commercial form. The moist filter cake has the disadvantage, however, that it is not flowable. He can not to be poured or poured, but with the Bucket dosed or decanted manually. That's why too have already been proposed in the form of polycarboxylic acids use high-percentage aqueous dispersions.
• Corrosion inhibitors also developed on the basis of melamine are already known. For example, US-A-2,485 309 methylolmelamine condensation products described but the high demands that are placed on an anticorrosive today are not sufficient. About that from European patent application 0 846 690 already melamine polycarboxamides and their use as Anticorrosive known. It is for their manufacture however, the polycarboxylic acid or the like is required Polycarboxylic acid halide, the polycarboxylic anhydride or the polycarboxylic acid ester in a reaction vessel melt using heat and then, if necessary, also using an inert protective gas melamine in the Stir in melt. This reaction generally a temperature between 120 and 180 ° C maintained.
• the reaction product can then cool off from the reaction vessel removed and in an aqueous alkaline solution to the anti-corrosion agent. Because this manufacture the melamine polycarboxylic acid amide was expensive the task of an equally good or better effective corrosion protection agent to develop on the basis of melamine, in which the Production of acid amide bonds is not required.
• a corrosion protection agent the melamine and an organic polycarboxylic acid of the formula I. in a molar ratio of 1: 1.5, preferably in a molar ratio of 1: 3, where X is a straight-chain or branched alkylene or alkylidene radical having 1 to 20 carbon atoms, which carry one or more hydroxyl or carboxyl groups and a cyclopentylene, cyclohexylene or may contain phenylene group.
• Suitable polycarboxylic acids are butanedioic acid Pentanedioic acid, hexanedioic acid, heptanedioic acid, the Nonandioic acid and particularly preferably also as sebacic acid designated decanedioic acid.
• the carbon chain of these dicarboxylic acids can also be a cyclopentylene, cyclohexylene or Contain phenylene radical.
• citric acid or an ethylene oxide or dicarboxylic acid containing propylene oxide units can together in the anti-corrosion agent according to the invention be included with melamine.
• Polycarboxylic acids especially mixtures of several Dicarboxylic acids can be used in the anti-corrosion agent according to the invention be used.
• Polycarboxylic acids can also be monocarboxylic acids Example the isononanoic acid may be present in the mixture.
• the carboxylic acids mentioned react with melamine in aqueous Solution with salt formation.
• the resulting salts are characterized by sufficient solubility in water so that aqueous solutions can be prepared that these compounds in an amount of 0.1 to 10 weight percent contain.
• the anti-corrosion agent according to the invention is preferred used in aqueous systems.
• aqueous system are water circuits, for example cooling water circuits, Circulations of aqueous machine fluids and coolants that are used during drilling, milling, milling, Turning, cutting, sawing, grinding, thread cutting or used in rolling and drawing metals.
• Antifreeze or hydraulic fluids Glycol water base as well as aqueous paints, for example Dispersion paints or aqueous powder coatings can be used with the Corrosion protection agent according to the invention anticorrosive be equipped.
• the anti-corrosion agent according to the invention can be in aqueous Systems as a sole addition or in combination with others Additives are used.
• Additives are used.
• Known corrosion inhibitors such as Phosphonates, phosphonocarboxylic acids or phosphinocarboxylic acids, N-acyl sarcosines, imidazolines, triethanolamine or fatty amines.
• Copper passivators such as water-soluble benzotriazoles, Methylene-bis-benzotriazoles or 2-mercaptobenzothiazoles can be added.
• Dispersants and Carriers such as poly (meth) acrylic acid and its salts, hydrolyzed polyacrylonitrile, polyacrylamide and the like Copolymers, lignosulfonic acid and their salts, starch and Starch derivatives, cellulose, alkylphosphonic acids, 1-aminoalkyl-1,1-diphosphonic acids and their salts, polymaleic acids and other polycarboxylic acids or alkali phosphates are added.
• additives can be precipitants, such as alkali phosphates or alkali carbonates, oxygen scavengers such as Alkali sulfates or hydrazine, complexing agents such as Nitrilotriacetic acid or ethylenediamine tetraacetic acid and their salts or anti-foaming agents such as distearyl sebacic acid diamide, Distearyladipinklarediamid or ethylene oxide or Propylene oxide condensation products of such amides as well Fatty alcohols and their ethylene oxide condensation products.
• precipitants such as alkali phosphates or alkali carbonates, oxygen scavengers such as Alkali sulfates or hydrazine
• complexing agents such as Nitrilotriacetic acid or ethylenediamine tetraacetic acid and their salts or anti-foaming agents
• the anti-corrosion agents according to the invention can also in Form of aqueous dispersions can be used.
• Dispersants are suitable for all surface-active compounds, especially anionic and non-ionic surfactants.
• Such dispersions can be thickened to be stabilized, with stabilizers in particular modified polysaccharides from xanthan, alginate, guar or Cellulose type used. This also includes cellulose ethers such as Methyl cellulose or carboxymethyl cellulose and heteropolysaccharides.
• the dispersions according to the invention can also be used for other Contain auxiliaries, for example hydrotropic agents such as Urea or sodium xylene sulfonate; Antifreeze like Ethylene or propylene glycol, diethylene glycol, glycerin or Sorbitol; Biocides such as chloroacetamide, formalin or 1,2-benzisothiazolin-3-one or complexing agents.
• hydrotropic agents such as Urea or sodium xylene sulfonate
• Antifreeze like Ethylene or propylene glycol, diethylene glycol, glycerin or Sorbitol
• Biocides such as chloroacetamide, formalin or 1,2-benzisothiazolin-3-one or complexing agents.
• the dispersions thus produced are at Room temperature as well as several at temperatures up to 40 ° C Stable for months. They keep their fluidity and segregate not yourself. That is for the storage and transportation of the Dispersions are an important property. For using the Dispersions have the advantage that they are like liquids can be handled and very quickly in alkaline water Systems.
• Corrosion protection agent was carried out according to the Regulation of DIN 51360 part II. Serve as a measure of corrosion the corrosion drawings on a round filter paper, that when exposed to artificially corrosive water on gray cast iron chips in the presence of the anti-corrosion agent arise. The test is carried out in the following way:
• water with a total hardness of 3.58 mmol is prepared from CaCl 2 x 6 H 2 O and MgSO 4 x 7 H 2 O, with 3% of the above-mentioned corrosion protection agent and with this Solution that wets gray cast iron chips distributed on round filters in a Petri dish. After a dwell time of 2 hours at room temperature, the gray cast iron chips are removed from the round filter, the round filter is rinsed and dried and then the degree of corrosion is determined visually according to the table in DIN 51360, Part II. The results obtained are shown in the table above.

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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)
• Treatment And Processing Of Natural Fur Or Leather (AREA)
• Chemical And Physical Treatments For Wood And The Like (AREA)
• Anti-Oxidant Or Stabilizer Compositions (AREA)

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Cited By (6)

Citations (6)

• 1999
  • 1999-03-30 DE DE59909853T patent/DE59909853D1/de not_active Expired - Fee Related
  • 1999-03-30 EP EP99106518A patent/EP1041174B1/fr not_active Expired - Lifetime
  • 1999-03-30 AT AT99106518T patent/ATE270352T1/de not_active IP Right Cessation

Patent Citations (6)

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