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
  • C23F11/14—Nitrogen-containing compounds
  • C23F11/141—Amines; Quaternary ammonium compounds
  • C23F11/143—Salts of amines

Definitions

• This invention relates to non-petroleum based metal corrosion inhibitors.
• Inhibited petroleum based oils are widely used as coatings for inhibiting the corrosion of various steels. This type of protection, however, is becoming increasingly impractical due to cost, the hazardous conditions created by the use of the petroleum based coatings, difficulty in removing the coatings and difficulty in disposing of the oil following its removal from the steel. Additionally, so-called smudging is sometimes caused by the polymerization and oxidation of petroleum based inhibitor- compositions. Since the surface of steel is microscopically porous, sufficient oil is absorbed into the surface to cause such smudging even after removal of the petroleum based inhibitor. In spite of these problems, these oil coatings continue to be used since they provide the required protection against corrosion and also serve to provide lubrication.
• a metal corrosion inhibiting composition which is a water-based solution of:
• a metal corrosion inhibiting composition which is a water-based solution of the aliphatic, monobasic acid, the aromatic acid and amines is provided.
• the composition according to the present invention is generally prepared as a concentrated aqueous solution containing from about 25 to about 65% by weight of the non-aqueous components. For application to metal surfaces, this concentrate is generally diluted up to about 5 times with water, i.e., 5 parts of water to 1 part of the concentrate.
• the composition offers protection against oxidation to aluminum, zinc coated or galvanized steel, aluminum coated steel, tin plated steel, stainless steel, high carbon electrical grade steel, cold rolled carbon steel and the like.
• the non-petroleum based corrosion inhibiting composition according to the present invention including a preferred composition which contains a minor amount of a petroleum oil, appears to be an aqueous solution of a reaction mixture of the various components. The exact mechanism of the formation of the solution, however, is not known.
• Relatively high molecular weight aliphatic, monobasic acids are employed in preparing the non-petroleum based composition according to the present invention.
• Aliphatic acids having from about 8 to about 20 carbon atoms have been found to be useful in preparing the composition. These acids include fatty acids, both saturated and unsaturated, such as caprylic acid, palmitic acid, stearic acid, oleic acid and linoleic acid and'resin acids such as abietic acid and acids isomeric therewith. These acids can be used alone or in combination.
• a mixture of tall oil fatty acids and rosin is used as the high molecular weight aliphatic acid component of the composition.
• Such mixtures are obtained as a byproduct of the paper industry from tall oil usually recovered from pine wood "black liquor”.
• Oleic and linoleic acids are the major components of the tall oil fatty acids with acids such as palmitic acid, isostearic acid and stearic acid being present in relatively minor amounts.
• oleic acid and linoleic acid comprise about 45% and 35% by weight, respectively, of the fatty acids.
• Rosin is mainly comprised of isomeric forms of abietic acid.
• the rosin can be present in amount of from about 5 to 40% by weight; preferably, lO to 40% by weight, of the tall oil fatty acid/rosin mixture. Mixtures containing less than about 5% by weight of rosin cannot be used because of problems relating to viscosity. Increased amounts of rosin appear to decrease the viscosity of the corrosion inhibiting composition. Mixtures containing more than about 40% rosin are not economical.
• non-petroleum based corrosion inhibiting compositions can also be employed in preparing the non-petroleum based corrosion inhibiting compositions according to the present invention.
• the high molecular weight aliphatic, monobasic acid component of the corrosion inhibiting composition is employed in an amount of about 5 to 20 parts by weight based on about 100 parts by weight of the concentrated solution.
• the composition according to the present invention typically contains a minor amount of a lubricant which may be either a petroleum or a non-petroleum product.
• a lubricant which may be either a petroleum or a non-petroleum product.
• Any of the petroleum oils presently employed in petroleum based corrosion inhibiting compositions for steel are believed to be useful in the present composition. Good results have been obtained using a 100 SSU viscosity petroleum oil.
• esters such as butyl stearate, dioctyl sebacate, butyl benzoate, or any of the light alkyl esters with boiling ranges above 350°F can be used as the lubricant.
• a petroleum oil is used as the lubricant.
• the amount of lubricant is limited by the amount of the high molecular weight aliphatic acid. More particularly, the lubricant is employed in an amount of from about 10 to 20% of the aliphatic acid, i.e., 0.5 to 4 parts by weight per 100 parts by weight of the concentrated solution. Amounts of greater than about 20% are not completely solubilized in the composition.
• the lubricant can be omitted from the metal corrosion inhibiting compositions.
• Such compositions will provide coatings which give good corrosion protection and which have a lubricity similar, for example, to soapy water.
• Such lubricity is believed to result from amine soaps or salts of the aliphatic and aromatic acids employed in the compositions.
• the aminoalkylalkanolamine of the metal corrosion inhibiting compositions according to this invention has the following general structural formula: wherein R l and R 2 are independently alkylidene of 1 - 4 carbon atoms and R 3 is hydrogen or alkyl of 1 - 4 carbon atoms.
• R l and R 2 are independently alkylidene of 1 - 4 carbon atoms and R 3 is hydrogen or alkyl of 1 - 4 carbon atoms.
• R l and R 2 are independently alkylidene of 1 - 4 carbon atoms and R 3 is hydrogen or alkyl of 1 - 4 carbon atoms.
• the metal corrosion inhibiting composition according to the present invention includes as a corrosion inhibitor a water-soluble amine salt of an aromatic acid.
• an aromatic monocarboxylic acid such as benzoic acid or an aromatic polycarboxylic acid such as phthalic, isophthalic, terephthalic or trimellitic acid. Mixtures of the aromatic acids may also be employed. Although it has not been confirmed, it is believed that the aromatic acids may also contain other functional groups such as hydroxy and lower alkyl groups which do not inhibit the formation of the water-soluble salt. Good corrosion inhibiting effects have been obtained employing about 10 to 35 parts and, particularly, 24 to 35 parts of the aromatic acid per 100 parts by weight of the concentrated solution.
• any primary, secondary, tertiary or cyclic amine which forms the water-soluble salt with the aromatic acid can be used in the composition according to the present invention to provide corrosion inhibiting properties. Particularly good results have been obtained with the use of (lower C 2 -C 4 ) alkanolamines and, particularly, monoethanolamine and diethanolamine. Other suitable amines are triethanol, diisopropylamine, cyclohexylamine and morpholine. The amines can be used alone or in combination.
• the amines employed in the metal-corrosion inhibiting composition according to the present invention also serve to neutralize the aliphatic acid and appear to assist in the solubilization of the lubricant component.
• the total amount of amines employed in the composition is generally in slight excess of the amount required to neutralize, i.e., form salts with, the aliphatic and aromatic acids.
• this amount of the amine component is typically within the range of 5 to 25 parts by weight per 100 parts by weight of the concentrated solution. In preferred embodiments the amount is within the range of 15 to 20 parts by weight per 100 parts by weight of the concentrate.
• the non-aqueous components of the compositions are employed in an amount of from 25 to 65 parts per 100 parts by weight of the concentrate.
• the non-aqueous components are employed in an amount of from 55 to 65 parts per 100 parts by weight of the concentrate; the remainder of the concentrate being water.
• the concentrated solutions are diluted up to 5 times, preferably about 4 times, with water, i.e., up to 500 parts of water per 100 parts of the concentrate.
• the mixture of the above-described aliphatic, monobasic acid component and lubricant are added to water with stirring in a suitable mixing device. This is followed by the addition of the aminoalkylalkanolamine which causes the formation of a cloudy emulsion. An amount of the amine (which forms the water-soluble salt with the aromatic acid) in excess of that required to form a clear solution from the cloudy emulsion is then added followed by the aromatic acid and the remainder of the salt-forming - amine. In another variation, a solution of the aromatic acid and salt-forming amine can be added to a solution of the aliphatic acid - lubricant - aminoalkylalkanolamine.
• a unique characteristic of the present invention is that following these procedures, a lubricant, either natural or synthetic, can be completely solubilized in water when the amounts of the components of the non-petroleum based inhibitor concentration are maintained within the ranges described above.
• composition prepared as described above is diluted with up to 5 parts of water and applied as either a rust preventative and/or lubricant.
• the recommended dilution ratio is 1 part concentrate to about 4 parts water.
• compositions according to the present invention are formed by the sequential addition of the following compounds to 250 lbs (about 30 gallons; 113 kg, 114 litres) of water with stirring (weights are approximate): and
• composition according to the present invention does not have to be removed from the surface of metals prior to painting in most cases. However, when it must be removed, water will remove it from the surface. The water can be discharged into drains since the solution is biodegradable.
• the inhibitor composition of the present invention When employed in a steel making operation, the inhibitor composition of the present invention should be applied after pickling and hot roll reduction operations, and prior to cold reduction, because the cleaned pickled sheet is very susceptible to rusting. Reapplication of the composition after the final reduction protects the coils during storage prior to annealing.
• the composition can be reapplied at the temper mill operation, either on the entry or exit side of the temper mill. When the composition is applied at the entry side, a very fine mist application is desirable so as not to cause problems on the temper mill rolls.
• the composition is applied at the exit side of the temper mill either as a light or heavy spray. This also applies when the solution is applied at the stretch or shear line.
• compositions were prepared according to the general procedures described above.
• percentages are by weight and the tall oil fatty acids/rosin mixtures employed are commercially available compositions in which the fatty acids are- composed primarily of a mixture of oleic and linoleic acids:
• compositions were evaluated for corrosion , inhibiting properties according to the testing procedures described below. Data for other corrosion inhibiting compositions are presented for comparative purposes.
• Cold roll dry strips (1 1/4", 3.2cm. wide by 4", 10.2cm. long, dry, clean and rust-free) were used as test specimens.
• a 1/16" (l.6mm.) hole was punched 1/8" (3.2 mm.) form the top and bottom, and 5/8" (1.6'cm.) from one side.
• a hook, fabricated from galvanized wire, was used to hang the strips in a humidity cabinet. Each strip was marked for identification by embossing a number with a metal stamp about 1/4" (6.4mm.) bolow the punched hole.
• a strip as described above was dipped 2" (5cm.) in the solution to be tested and suspended by a metal hook with the dipped or coated portion of the strip at the bottom.
• the strip was allowed to dry or drain for one hour, and the hook transferred to the opposite end of the strip, which was then suspended on a rack in the humidity cabinet.
• the coated or dipped end was now on top, and the lower, uncoated end of the strip on the bottom.
• the conditions in the humidity cabinet were maintained a 100°F (38°C) and 100% humidity.

Priority Applications (1)

Applications Claiming Priority (4)

Publications (3)

Family

ID=26714118

Family Applications (1)

Country Status (3)

Cited By (6)

Citations (3)

• 1980
  • 1980-05-08 PL PL22410880A patent/PL131859B1/pl unknown
  • 1980-05-09 DE DE8080301531T patent/DE3067103D1/de not_active Expired
  • 1980-05-09 EP EP19800301531 patent/EP0020042B1/de not_active Expired

Patent Citations (3)

Also Published As

Similar Documents

Legal Events