Classifications

• • C—CHEMISTRY; METALLURGY
  • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
  • C02F5/00—Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents
  • C02F5/08—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents
  • C02F5/10—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances
  • C02F5/12—Treatment of water with complexing chemicals or other solubilising agents for softening, scale prevention or scale removal, e.g. adding sequestering agents using organic substances containing nitrogen
• • 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
  • C23F11/173—Macromolecular compounds

Definitions

• the operation of industrial water systems is generally not possible without the use of anti-corrosion agents and hardness stabilizers.
• the classic means for this purpose are phosphorus-containing substances, e.g. Polyphosphates or phosphonic acids.
• the object of the present invention was therefore to find more effective agents of the type mentioned which are not phosphorus-containing compounds and are therefore of considerable technical interest.
• telomerizates from telogen and acrylic compounds containing mercaptan groups are expediently used in amounts of 0.1 to 100, in particular 1 to 30 ppm, based on the process water.
• Sodium and potassium are of course primarily considered as alkali metal ions. Of course, these can also be replaced in whole or in part by optionally substituted ammonium ion.
• the telomerizates to be used according to the invention can be prepared by known processes (for example, see US Pat. No. 3,498,942).
• the reaction of alkyl mercaptan, acrylonitrile and acrylic acid in an anhydrous medium such as e.g. carried out in low molecular weight aliphatic alcohols, such as methanol, ethanol or propanol.
• the reaction temperature can be varied within wide limits from about 20 to about 100 ° C, but is generally between 20 to 70 ° C.
• the reaction is carried out in the presence of a conventional radical initiator, such as e.g.
• telomerisate obtained in this way is usually suitable for use as a stone and corrosion inhibitor without further purification.
• Alkyl mercaptans with preferably a straight-chain primary, branched-chain primary, secondary or tertiary alkyl group with 8 to 18 carbon atoms, such as, for example, n-octyl mercaptan, n-decyl mercaptan, t-dodecyl mercaptan, hexadecyl mercaptan, octadecyl mercaptan, are used.
• unsaturated monomers come especially acrylic acid and methacrylic acid and the corresponding amides and also acrylonitrile and methacrylonitrile.
• acrylamide telomerizates are compounds of the general formula in which R represents an aliphatic hydrocarbon radical having 8 to 18 carbon atoms, X is hydrogen or a methyl group and m are numbers from approximately 6 to 20.
• telomerization of the nonionic, i.e. Polymers containing amide and optionally nitrile groups are carried out as previously explained.
• the reaction mixture is advantageously worked up by precipitation with solvents, such as, for example, lower hydrocarbons or, in particular, diethyl ether. In this way, even through sogn. Accidental cleaning can be carried out. In general, however, this is not necessary.
• the solution was concentrated on a Rotavapor, dissolved in warm water with aqueous ethanol and precipitated in ether. Approx. 90% of the telomer was dispersed in water, neutralized to pH 10 with dilute sodium hydroxide solution, precipitated in ethanol and dried to constant weight in a vacuum drying cabinet.
• telomeres In order to recover the telomeres, some of which were still in solution, 2.5 liters of ether were added as the precipitant and the precipitate formed was filtered off. The precipitate was washed with acetone, filtered and in Vacuum drying cabinet dried to constant weight.
• telomeres The yield of telomeres was 609 g (corresponding to 79% of theory).
• the sulfur content of the product was 4.15% and the distribution of the monomer fractions in moles in the telomer was 1 mol of n-dodecyl mercaptan: 8.6 mol of acrylamide (product A).
• test water with the substance according to the invention contained therein is conveyed through a heat exchanger by means of a peristaltic pump.
• the hardness deposited on the wall of the heat exchanger is dissolved in dilute hydrochloric acid and Ca0 is determined titrimetrically in this solution.
• the relation to a blank value without dosing is given:
• the test water had the following German degrees of hardness:
• Table 1 below shows the values found for substance A in comparison with the so-called zero value.
• Corrosion behavior is determined using the coupon method. For this purpose, iron dissolved in solution is determined after a certain test period due to the corrosion process and is given in relation to a blank value without addition of the products to be used according to the invention.
• the percentage iron content is calculated according to:
• Table 2 shows the corrosion protection effects in%, depending on the acrylic telomerisates according to II.
• a technical cooling system with a content of 1.2 m 3 and a circulation of 8 m 3 / hour. is operated with Düsseldorf city water.
• the main analysis data were: total hardness 16 ° dH, of which carbonate hardness 8.5 ° dH at a pH of 7.4 and a chloride content of 165 mg / l.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Environmental & Geological Engineering (AREA)
• Hydrology & Water Resources (AREA)
• Life Sciences & Earth Sciences (AREA)
• General Chemical & Material Sciences (AREA)
• Water Supply & Treatment (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Preventing Corrosion Or Incrustation Of Metals (AREA)
• Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)

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Citations (3)

• 1977
  • 1977-07-07 DE DE19772730645 patent/DE2730645A1/de not_active Withdrawn
• 1978
  • 1978-06-19 EP EP78100185A patent/EP0000337A1/fr not_active Withdrawn
  • 1978-07-05 IT IT25342/78A patent/IT1097813B/it active

Patent Citations (3)

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