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
  • C23F11/04—Inhibiting corrosion of metallic material by applying inhibitors to the surface in danger of corrosion or adding them to the corrosive agent in markedly acid 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
  • C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
  • C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
  • C23G1/02—Cleaning or pickling metallic material with solutions or molten salts with acid solutions
  • C23G1/04—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors
  • C23G1/06—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors
  • C23G1/068—Cleaning or pickling metallic material with solutions or molten salts with acid solutions using inhibitors organic inhibitors compounds containing a C=C bond

Definitions

• This invention relates to compositions for inhibiting the corrosion of metals placed therein, and to novel acetylenic amines for such use as corrosion inhibitors.
• novel acetylenic amines and aqueous compositions for inhibiting the corrosion of metals placed therein which comprises:
• the compounds of the invention are made by a catalytic reaction, followed by purification, such as by molecular distillation of the crude reaction product under vacuum, or liquid chromatography.
• aldehyde reactions employed in this invention include 2-ethylhexanal, benzaldehyde, cinnamaldehyde, 2,4-dichlorobenzaldehyde, 4-methylbenzaldehyde, 4-ethoxybenzaldehyde, 2-chlorobenzaldehyde, 2,4-dichlorocinnamaldehyde, 2-chlorocinnamaldehyde, 2-methoxycinnamaldehyde, 4-ethylcinnamaldehyde, etc.
• the reaction is carried out in the presence of an ethynylation catalyst, such as is used for commercial preparation of'butynediol; see, e.g. U.S. patents 3,920,759; 4,117,248; and 4,119,790.
• the preferred catalyst is a complex cuprous acetylide prepared from a precursor containing about 5-35% by weight of copper, and 2-3% by weight of bismuth, as the oxides, on a magnesium silicate carrier.
• ethynylation catalysts and carriers known in the art may be used as well.
• the ethynylation reaction can be run under either low or high pressure conditions, i.e. a partial pressure of acetylene, as is used for butynediol, generally from about 0.1 atmosphere to 20 or more atmospheres, either in a stirred reactor with a slurried catalyst, or in a fixed bed, through which the acetylene and the solution are passed.
• low or high pressure conditions i.e. a partial pressure of acetylene, as is used for butynediol, generally from about 0.1 atmosphere to 20 or more atmospheres, either in a stirred reactor with a slurried catalyst, or in a fixed bed, through which the acetylene and the solution are passed.
• the ethynylation process preferably is carried out in the presence of a solvent in which the reactants are at least partially soluble.
• a solvent in which the reactants are at least partially soluble.
• An organic solvent which is inert to the reaction may be used advantageously; preferably it is also volatile so that it can be easily separated from the reaction product by distillation. Alcohols, hydrocarbons and other organic solvents such as a ketone, e.g. methylethylketone or acetone, or an amide, e.g. dimethyl formamide may be used for this purpose.
• a preferred organic solvent is either dry or aqueous methanol or isopropanol.
• Water also is a suitable solvent; however, water does not completely dissolve the reactants, and it wets the catalyst, which interferes with intimate contact with the organic reactants. Consequently, ethynylation reaction rate is slower in water than in an organic solvent which forms a single liquid phase.
• mixtures of an organic solvent and water may be used, most suitably those which give a single reacting liquid phase.
• a charge is made of the reactants in relatively stoichiometric proportions of the secondary amine and aldehyde in an alcoholic solvent.
• the charge then is heated to a temperature of about 70 to 1150C., preferably 85 0 to 105°C., and acetylene is introduced and maintained at the desired pressure.
• the reaction is effected over a period of from less than 1 to 36 hours, generally for a period of from about 0.2 to 8 hours.
• GC Gas chromatographic
• the purified compound may be characterized by its IR and NMR spectra.
• the IR spectrum shows the presence of a strong sharp C-H stretching absorption band at about 3320 cm 1 , attributable to the ethynyl group, and an absence of carbonyl absorption in the region of 1600-17 00 cm -1 .
• the aldehyde reactant is a benzaldehyde or cinnamaldehyde
• the NMR spectrum of the product shows distinctive absorptions related to the portion of the molecule.
• the C-1 proton is evident by a doublet at 3.1-5.2 ⁇ due to coupling of the C-3 proton with the C-1 proton.
• the C-3 proton also shows up as a doublet for the same reason; however, at 2.0-3.0 ⁇ .
• the NMR spectrum of the product shows distinctive absorptions related to the portion of the molecule.
• the C-3 proton also shows up as a doublet by coupling with the C-1 proton; however, at 2.0-2.2 ⁇ .
• the NMR spectrum of the compounds herein reveals the absence of both an aldehyde proton absorption, which is present in the starting material at 9-10 ⁇ , and any N-H absorption.
• the crude ethynylation reaction product is a complex mixture which, in the case of ethylhexanal, contains predominately 3-dialkylamino-3-phenyl- ethenylprop-1-yne, 3-dialkylamino-3-ghenylprop-1-yne or the phenyl substituted derivatives thereof or corresponding N-phenylamino derivatives, depending on the reactants selected.
• the product contains predominately the two diastereoisomers of the 3-dialkylamino-3-(1-ethylpentyl)prop-1-yne, in the ratio of about 3:1 to 4:1 of each other.
• the products of these reactions may contain some of the corresponding di-compound, having the formula: and also some 3-dialkylaminobutyne, e.g. R 1 R 2 NCH(CH 3 )C ⁇ CH, and, depending upon reaction conditions, unreacted starting materials, and lesser amounts of other materials.
• the reaction product itself may be used as a corrosion inhibitor without purification or isolation of the predominate compound therein. This option is particularly attractive from a commercial standpoint, because of the economic feature, and, indeed, the crude reaction product often performs as well or better under more severe testing conditions than does the purified compound. This effect may be due to the presence of by-products in the reaction product which may act as a synergist with the predominate compound.
• the corrosion-inhibiting compositions of the invention may be used at varying concentrations. What is an effective amount in a particular application will depend upon local operating conditions. For example, the temperature and other characteristics of the acid corrosion system will have a bearing upon the amount of inhibitor to be used. The higher the temperature and/or the higher the acid concentration, the greater is the amount of corrosion inhibitor required to give optimum results. In general, however, it has beenfound that the corrosion inhibitor composition of the invention should be employed at a concentration of between 0.01 and 2%, preferably between 0.01% and 1.2%, by weight of the aqueous acidic solution, although higher concentrations can be used when conditions make them desirable. An inhibitor concentration between 0.05% and 0.75% by weight is of the most general use, particularly at elevated temperatures, e.g. in the neighborhood of 200°F.
• the acidic solution itself can be dilute or concentrated as desired, and can be of any of the specific concentrations customarily used in treating metals, e.g. ferrousmetals, or for operations involving contact of acidic solutions with such metals in oil-well acidizing.
• the acid content is about 5 to 80%, and, in most operations of the character indicated, acid concentrations of 10-15% by weight are employed.
• Non-oxidizing inorganic acids are the most common acids used.
• a charge is made to a 1-1. stirred autoclave consisting of 1 mole (129 g) of dibutylamine, 1 mole of the aldehyde shown in Table I, 25 g of a 35 wt. % Cu-containing catalyst, prepared as described in U.S. 4,119,790, as a powder, and 350 ml of isopropanol.
• the reactor is purged well with nitrogen, released to atmospheric pressure, and the reactants are heated to 95°C. The vapor pressure at this point is recorded. Acetylene then is admitted at a pressure of 100 psig above the recorded pressure. The amount of acetylene furnished to the reaction is measured by the loss in weight of the supply cylinder.
• N,N-diphenyl substituted acetylenic amine products are produced by using N,N-diphenyl-amine as the starting material;
• the N,N-dipropyl acetylenic amine products are prepared by employing N,N-dipropyl amine reactant;
• the N-methyl-N-phenyl acetylenic amine products are obtained from N-methyl-N-phenylamine reactant; etc.
• the most preferred inhibitors of this invention are the dialkylamino halogenated phenyl prop-1-ynes and dibutylamino alkylpentylprop-1-ynes.
• the compounds of the present invention were tested in the usual way to determine their effectiveness as corrosion inhibitors.
• strips of 1020 carbon steel of the dimensions 2.5" x 1.0" x 0.20" were first degreased with methylethyl ketone and then descaled by soaking in 10% hydrochloric acid solution containing approximately 0.1% propargyl alcohol.
• the coupons then were cleaned with a brush and thoroughly rinsed with water. After rinsing, the coupons were soaked in 2% sodium carbonate solution, rinsed successively with water and acetone and air dried.
• the surface dimensions of the cleaned coupons were determined with the vernier scale and the coupons were allowed to dry in a desiccator. Before use the coupons were weighed on an analytical balance.
• the tests were carried out in a 4 oz. jar containing a weighed amount of the inhibitor. The total solution weight was taken to 100.0 g with the addition of hydrochloric acid solutions at concentrations noted in Table II.
• the coupon then was placed in the mixture and the jar loosely capped and placed in a 80°C. oil bath. After the designated hours, the jar was removed from the oil bath and the contents were allowed to attain ambient conditions. The coupon was removed from the acid solution, thoroughly washed with water, 2% sodium carbonate solution, again with water, and finally rinsed with acetone. After air drying the coupon was kept in a desiccator before weighing and the net weight loss was calculated by the established procedure.
• the compounds of the invention exhibit excellent corrosion inhibition for metal in aqueous acid solution. These compounds perform substantially better than the corresponding dialkylamino compounds which are unsubstituted or which contain lower alkyl substitutions, either straight chain, branched chain or cyclic. This result is attributable primarily to the long chain alkyl group and its branching groups at the 1-position.

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Citations (4)

• 1982
  • 1982-09-13 EP EP82304806A patent/EP0080794A1/de not_active Withdrawn

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