DE1282415B - Agents for inhibiting corrosion - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Ο .:

C23f

German class: 48 dl - 11/10

Number: 1282415

File number: P 12 82 415.6-45 (D 43744)

Filing date: February 27, 1964

Open date: November 7, 1968

The invention relates to a synergistic mixture of organic nitrogen and sulfur compounds, which when introduced into normally corrosive solutions, the attack of the corrosive components of the Avoid solution on metal.

The corrosion inhibitor according to the invention consists of

A. 1 to 9 parts by weight of the reaction product

1. 1 mole of an ammonia derivative with at least one bonded to nitrogen Hydrogen atom, which no other reactive under the reaction conditions Has groups as hydrogen,

2. 1.5 to 10 mol of a ketone which has at least ¹ ^ at least 1 hydrogen atom on the carbon atom adjacent to the carbonyl group,

3. 2 to 10 moles of an aliphatic aldehyde having 1 to 16 carbon atoms and / or aromatic Benzene series aldehydes with no functional groups other than aldehyde groups,

4. 0 to 5 moles of acid catalyst and

5. 0.3 to 24 parts by weight, based on the sum of 1, 2, 3 and 4, of a fatty acid with 1 to 20 carbon atoms

at a temperature of about 65 to 120 ° C for about 24 hours and off

B. 9 to 1 part (s) by weight based on the inhibitor, one of the following sulfur compounds: ferric sulfide, Thiourea and its aliphatic homologues, aliphatic sulfides, alkali thiocyanates, aliphatic thiocyanates, thio acids, mercaptothiazolines, mercaptans, and mixtures of two or more compounds from the same group or different groups of the listed sulfur compounds.

The inhibitor mass effectively prevents the attack of aqueous solutions of corrosive substances on metals, for example ferrous metals, copper and zinc. It also proved beneficial to be a nonionic surfactant, for example an alkylphenoxypolyalkyleneoxyalkanol, to make it easier to produce clear solutions of the inhibitor in the corrosive solution. It should be noted that that the surface active agent is not necessary, but it makes a good-looking preparation Achieved, and it also acts to the effect of scaling means to inhibit corrosion

Applicant:

The Dow Chemical Company, Midland, Mich.

(V. St. A.)

Representative:

Dipl.-Ing. F. Weickmann,

Dipl.-Ing. H. Weickmann and Dr. K. Fincke,

Patent Attorneys, 8000 Munich 27, Möhlstr. 22nd

Named as inventor:

James Preston Engle, Duncan, Okla .;

Cecil Fred Reich, Tulsa, Okla .;

Billy Dean Oakes, Midland, Me. (V. St. A.)

Claimed priority:
V. St. v. America February 27, 1963
(261509)

and other deposits in the more common uses which include aqueous solutions being more corrosive Substances are used, d. H. for cleaning boilers and industrial heat exchangers, in To keep suspension.

The inhibitors that can be considered according to the invention have various advantages over the known inhibitors, one of which is the better inhibition with a simultaneous higher cleaning power, since the corrosive substance, for example, an inorganic acid, such as HCl or H ₂ SO ₄ , or an organic acid, such as Alkylenediaminetetraacetic acid or partially ammonia-containing salts, are not lost when the metal is attacked. Another advantage is that the present inhibitors do not leave deposits on metallic surfaces like many other inhibitors.

809 630/1027

3 4

Another benefit of the present inhibitor is ureas, thioureas, ammonia and ammo in that the inhibitor, if necessary, can be converted into nium salts, alicyclic amines, heterocyclic amines, Can be prepared in such a way that no aromatic amines, imidazolines, which have an amine chloride ion by the inhibitors in the system contain nitrogen-substituted side chains, and be introduced. Another advantage is that there are five similar compounds which no other has nor in the fact that metals, such as copper and zinc, do not have a reactive group under the reaction conditions once weakly attacked and contain no waste except hydrogen bound to the nitrogen, deposits remain behind. On these and other some compounds that have been shown to be effective are Advantages will be in the following description in more detail the normal alkylamines with 1 to 20 or more To be received. io carbon atoms in the alkyl substituent, both

To produce the nitrogen-containing reaction, for example methylamine, ethylamine, butylamine, pen product of the inhibitor according to the invention, tylamine, heptylamine, octylamine, decylamine, dodecyl, a nitrogen compound containing at least one active hydrogen amine bonded to the amine, tetradecylamine, hexadecylamine, octadecyl nitrogen atom , Eicosylamine and mixtures thereof, which contains per molecule, with a ketone which is at least 15 isoalkyl and tert-alkylamines with up to 20 carbons one hydrogen atom on the one in the α-position to the substance atoms in the alkyl substituent, for example carbonyl group. Has carbon atom, isopropylamine, isobutylamine, isoamylamine, tert-an aldehyde and a fatty acid, preferably in butylamine and tert-amylamine, the dialkylamines with the presence of an acidic catalyst, at temperatures 1 to 20 carbon atoms in the alkyl substituents, do between about 65 and 12O ⁰ C for 1 to ao, for example, dimethylamine, diethylamine, dipropyl · reacted for about 24 hours. The crude reaction pro - amine, dibutylamine, diamylamine, dihexylamine, diduct is then optionally mixed with an additional amount of heptylamine, dioctylamine, didecylamine and diocta-amount of fatty acid to determine the weight ratio of decylamine and the diiso- and tert-alkylamines and of fatty acid to active hydrogen aldehyde Ketone mixtures thereof. To diamines which, as a compound-HCl adduct, add 0.3 to 24 parts of fatty acid per part of the fertilizer containing active hydrogen, to bring usable adduct. It is preferable, but not essential, include the diamines having 1 to 20 carbon, the above reaction in the presence of atoms in the alkyl moieties thereof, for example a solvent such as. B. glycol or polyglycol, methylenediamine, ethylenediamine, propylenediamine, Bu execution. If the solvent is not used in the case of tylenediamine, diaminopentane and diaminohexane (hexylediamine, it turned out to be advantageous). In addition, others are nitrogen-rich, adding it after the reaction to make it easier to handle compounds with an active hydrogen handle. This product is then mixed with atom on the nitrogen atom such as ammonia, urine or sulfur compound to produce the inhibitor substances, thioureas, amides, ammonium salts and according to the invention. alicyclic, heterocyclic and aromatic amines,

A preferred embodiment for the preparation of compounds having an active hydrogen atom according to the inhibitor according to the invention is that the invention can be used. So you can ammonia that first the nitrogen compound is produced, urea, thiourea, l-acetyl-2-thiourea by adding (A) about 1 mole of the compound with active N-allylthiourea, dithiobiuret, l-phenyl-2-thio-hydrogen and 2 to 10 moles of aldehyde and 1.5 to urea, 1,3-di (kolophoniumamine D) thiourea, 10 moles of ketone and optionally 0 to 5 moles of 40 and 1,3-dibutylthiourea, acetamide, Nl-naph acid catalyst (B) 0.3 to 24 and preferably thylacetanüd, oxamide, acetamide, adipic acid amide, 0.3 to 3 parts by weight, based on reaction propionic acid amide, thioacetamide, malonic acid amide, participant A, a fatty acid at a temperature formamide, «-cyanacetamide, succinamide , n-Butyr between about 65 and about 120 ⁰ C for 1 to amide, acetamide, dimethylacetamide, N-methylacet-24 hours in the presence of a glycol, for example 45 amide, n-butyloxamate, hexanamide, phthalimide, n-Va-ethylene glycol, implemented will. After completion of leric acid amide, isobutyramide, armid 12 (95% D or conversion, additional fatty acid can be added under decanamide, 4% tetradecanamide, 1% decanamide), stirring to adjust the weight ratio of N, N'-dibenzyldithiooxamide, dithiooxamide, armid C of fatty acid to adduct to 0.3 to 24 parts by weight (amide of coconut fatty acids), 1-naphthylene acetamide, acid per part adduct. Then 50 Armid 0 (91% oleic acid amide, 6% stearyl amide, 3% the wetting agent in an amount of about 1 part linoleic acid amide), Ν, Ν'-dimethylthiooxamide, acetone to about 1 to 10 parts of the reaction product and an anilide, Armid HT (75 % Stearylamide, 22% palmitic alkali alcohol (acetylenic alcohol) in an amount of amide, 3% oleic acid amide), nonanamide, N, N'-dicyclo from 1 part to 6 to 19 parts of the reaction product hexyldithiooxamide, benzamide, B-isothioureidopro are added with stirring. The nitrogen-containing 55 pionic acid and N, N'-bis (hydroxymethyl) dithioox reaction product is then mixed with an amount between amide, 2-methylpiperazine, morpholine, pyrrolidine and V ₄ part up to twice its weight of a 2-aminoethylpiperazine, 2- Naphthylamine, benzylamine, sulfur compound mixed, or the two Ma- 2-aminopyridine and aniline, 1,3-diphenyltriazine, Amterialien are in any order to the monium chloride, monobasic ammonium phosphate, aqueous acid or other aqueous corrosive ammonium acetate, ammonium thiocyanate, ammonium Solutions added. umoxalate and dibasic sodium ammonium

As compounds with active hydrogen, which phosphate and also the imidazolines, such as 2-Aminozur Production of the nitrogen-containing component ethyl-l-n-heptyl-2-imidazoline, as an effective Verbingemäß of the invention can be used fertilize for active hydrogen according to the invention come to use such organic ammonia derivatives in 65.

The question as to which of the ketones which can be used according to the invention have at least one hydrogen atom

contain the nitrogen bonded, for example at least one hydrogen atom on the in «position primary and secondary amines, diamines, amides, carbon atom attached to the carbonyl group.

Some of these are shown to be effective aliphatic and aryl-substituted aliphatic ketones and mixtures thereof are, for example, acetophenone, 1-acetonaphthone, 1 part acetophenone + 1 part Acetone, p-methoxyacetophenone, propiophenone, p-chloroacetophenone, isophorone, tetrolophenone, 2,4-pentanedione, ketosol (75% phenethyl alcohol, 25% acetophenone), 2-acetylcyclohexanone, 2-acetonaphthone, 2-thienyl ketone, methyl isobutyl ketone, n-butyrophenone, acetone, 3,4-dihydro-1- (2H) -naphthalenone, 2-heptanone, diacetone alcohol and undecanone-2.

The class of fatty acids that have been found to be effective includes the alkyl carboxylic acids 1 to 20 carbon atoms including formic acid, olefinic carboxylic acids with 2 to 20 carbon atoms and with one to two or more unsaturation sites in the chain. It also proved the various alkylene oxide adducts of the foregoing acids are found to be effective. So you can recover Animal fat, octanoic acid, myristic acid, pelargonic acid, abietic acid, acetic acid, lauric acid, Formic acid, oleic acid, caproic acid, tall oil acid, coconut fatty acids + 15 moles of ethylene oxide, oleic acid + 15 moles of ethylene oxide, 70% colophony fatty acids + 15 moles of ethylene oxide, tall oil + 4 moles of propylene oxide + 8 moles of ethylene oxide, tall oil -r 6 moles of propylene oxide + 12 moles of ethylene oxide, tall oil + 8 moles Propylene oxide + 8 moles of ethylene oxide, tall oil + 4 moles of propylene oxide + 12 moles of ethylene oxide, tall oil + 4 moles Propylene oxide + 10 moles of ethylene oxide, tall oil + 6 moles of propylene oxide + 8 moles of ethylene oxide and tall oil + 6 moles of propylene oxide - use 10 moles of ethylene oxide.

The aldehydes also belong to the class of aldehydes which can be used according to the invention 1 to 18 or more carbon atoms. So you can use formaldehyde, urotropine, benzaldehyde, hexanal, Use Octanal, Decanal, Hexadecanal, etc.

Among the wetting agents that can be used with the inhibitor in some cases, include those known as anionic, nonionic, cationic, and amphoteric surfactants. Some of these Wetting agents are the mono- and dialkylphenols, which are condensed with 10 to 50 mol of ethylene oxide, for example nonylphenols, which are condensed with 10 to 50 moles of ethylene oxide, and di (sec-butyl) phenol, which is condensed with 5 to 30 moles of ethylene oxide, the polyethylene glycol alkyl mercaptans, for example Polyethylene glycol tert-dodecyl mercaptan, ammonium isopropylbenzene p-sulfonate, the diethanoiamide of coconut oil, the difatty acid quaternary alkyl ammonium chlorides of mixed fatty acid alkyl residues, such as. B. the octyl, decyl, tetradecyl, Hexadecyl and octadecyl radicals.

The alkynyl alcohols that can be used with the inhibitor according to the invention are acetylenic alcohols having 3 to 10 carbon atoms, for example l-propyn-3-ol, l-butyn-3-ol, 1-pentyn-3-ol, l- Heptin-3-ol, l-octin-3-ol, l-nonin-3-ol and l-decin-3-ol. The following alkynols are useful in Temraturen below about 65 ⁰ C: 1-Äthinylcyclohexanol, methylbutynol, methylpentynol and butynediol.

As acid catalysts for the production of the inhibitor, mineral acids such as sulfuric acid, Hydrochloric acid, phosphoric acid, and strong organic acids such as formic acid, acetic acid and propionic acid, be used.

The sulfur-containing compound used according to the invention as a synergistic ingredient consists of an organic sulfur-containing compound in which the sulfur is in the form of - S - or S = is present. Compounds that fall under this are thiourea and its aliphatic Homologues, the aliphatic sulfides, the alkali thiocyanates, the aliphatic thiocyanates, the thioacids, the mercaptothiazolines, the mercaptans, the mercaptobenzothiazoles and mixtures of two or more more connections from the same or different classes.

The following examples serve to further illustrate the invention.

example 1

A three-necked flask with a capacity of 11 was filled with 156 g of technical dehydroabietylamine,

65 g paraformaldehyde,
109 g 90% formic acid,
139 g acetophenone,
490 g ethylene glycol and

57 g concentrated H ₂ SO ₄ (98%)

loaded. The contents of the flask were heated to reflux (115 ⁰ C) for 16 hours with stirring. The flask was cooled to room temperature and 1 part by weight, based on the reaction mass, of nonylphenoxydoctaäthylenoxyäthanol was added to 3 parts by weight of the reaction mass. The mass obtained was in the following concentrations with allyl thiourea in 5% H ₂ SO ₄ to determine the corrosion-inhibiting properties on a mild steel with 0.08 to 0.13% C, 0.30 to 0.60% Mn, at most 0.04 % P and not more than 0.05% S used. The corrosion test was carried out by placing a weighed sample of the mild steel in 150 ml of 5% sulfuric acid containing the inhibitor, heating the acid to 65 ° C. and maintaining it at this temperature for 6 hours. At the end of the test, the steel sample was weighed and the loss in g / cm ² per day was calculated.

Acid 5% H ₂ SO ₄

Test duration 6 hours

Temperature 65 ° C

Steel sample mild steel sheet

(7.0 x 2.54 x 0.32 cm)

Inhibitory concentration Allyl-2-thiourea corrosion in percent by weight, 0.1 based on acid solution 1.0 g / cm ² / day Amine compound 0.0007 0.2 0.0009 0.2 0.1 0.0005 0.1 0.05 0.0010 0.1 0 0.013 0.3 0 0.011 0.2 0.3 0.017 0 0.012 0 0.1

Example 2

In the same manner as in Example 1, using 0.2 weight percent of the same Amine compound and other sulfur compounds obtained the following corrosion values. The value of Mixtures of the two components are compared in the right column with the value with the same percentage by weight of the sulfur compound alone.

Acid, water

Corrosion value
g / cm ² / day Comparative
Corrosion value Sulfur compound
0.1 percent by weight 0.0009 at 0.3 Ge
weight percent
the sulfur
link
alone Sodium mercapto-
benzothiazole 0.0018 0.024 Thiourea 0.0013 0.05 Ethyl sulfide 0.0008 - Sodium thiocyanate 0.0007 0.017 Mercaptothiazoline .. 0.0006 0.0046 N, N'-di-n-propyl-
thiourea 0.0007 Ethyl mercaptan ... 0.0007 - Methyl thiocyanate ... 0.0047 - Ν, Ν'-diallylthio-
urea 0.0012 1.0% FeS

21% H ₃ PO ₄

2% formic acid + 1% room

tronic acid

3% formic acid

3% hydroxyacetic acid

2% hydroxyacetic acid

+ 1% formic acid ...

5% HCl

7.5% sulfamic acid

3% citric acid

5% acetic acid

temperature

Corrosion value

g / cm ² / day

65

93 93 93

93 65 65 93 93

0.00024

0.0005 0.0005 0.0004

0.0004

0.00024

0.00024

0.0005

0.0004

Example 5

To illustrate the fact that two different sulfur compounds can be used with the same results, corrosion tests were carried out as in Example 1, the stated percentages of the second sulfur compound being used.
30th

Inhibitor Corrosion value g / cm ² / day 0.1% amine compound of the ³⁵ game 1 + 0.05% 1-Allyl- 2-thiourea and 0.05% 2-mercaptobenzothiazole 0.00038 0.1% amine compound + 0.05% ₄ o of a 50% aqueous Na- trium mercaptobenzothiazole solution and 1.0% 1-allyl 2-thiourea 0.0006

Example 3

The following shows the effect on the corrosion value if amines other than dehydroabietylamine are used can be used to prepare the amine compound. The different amines were in equivalents Amounts such as dehydroabietylamine are used. The test procedure was the same as in Example 1 described.

In the manner indicated in Example 1 was

an amine compound was prepared using an equivalent amount of HCl as a catalyst in place of H ₂ SO ₄ . The results of the corrosion tests carried out in the manner indicated above were as follows:

Example 6

Amine used in place of rotary hydroabietylamine

Thiourea

2- (butylthio) ethylamine ...
2- (dodecylthio) ethylamine
l-Allyl-2-thiourea ...

Example 4

Corrosion value g / cm ² / day

0.0008 0.00047 0.0010 0.00047

Concentration of the inhibitor

in 150 ml of 5% H ₂ SO ₄

in percent by weight

0.2 amine compound + 0.1 thio-

To explain the effectiveness of the inhibitors according to the invention in preventing corrosion by acids other than H ₂ SO ₄ , the following tests were carried out using the acids listed. The details of the corrosion test and the inhibitor used were as given in Example 1, unless otherwise stated.

urea

Corrosion value g / cm ² / day

0.0014

Example 7

The amine compound according to Example 1 was ^{mixed with x} / s part by weight of a surface-active agent which by condensation of nonylphenol with

20 mol of ethylene oxide was obtained, and _{mixed with a Vi 9} parts by weight of l-hexyn-3-ol. This inhibitor was treated with a 3.8% strength aqueous solution of ^e .n offset with ammonia ethylenediaminetetraacetic acid (pH 9.2), mixed, and corrosion tests were performed on 16 hours mild steel sheets at 149 ⁰ C. The following results were obtained:

Weight percent
Inhibitor Weight percent
Sodium nacapto
benzthiazole Corrosion value
g / cm ² / day without
0.1
0.1
0.1 *)
0.1 **) without
0.05
0.05
0.05
0.05 0.029 to 0.039
0.01
0.029
0.0005 to 0.001
0.0005 to 0.001
0.0005 to 0.001

IO

*) Without l-hexyn-3-ol.

**) Amine compound catalyzed with HCl, all other components as in Example 1.

Claims (5)

Patent claims: 1. Corrosion inhibitor, characterized by a content of A. 1 to 9 parts by weight of the reaction product 1. 1 mole of an ammonia derivative with at least one bonded to the nitrogen atom active hydrogen atom and no other group which is reactive under the reaction conditions than Hydrogen, 2. 1.5 to 10 moles of a ketone with at least one hydrogen atom on the car- 10 carbon atom adjacent to the bonyl group, 3. 2 to 10 moles of an aliphatic aldehyde having 1 to 16 carbon atoms and / or an aromatic aldehyde of the benzene series with no fractional groups other than aldehyde groups, 4. 0 to 5 moles of acid catalyst and 5. 0.3 to 24 parts by weight, based on the sum of 1, 2, 3 and 4, of a fatty acid having 1 to 20 carbon atoms at a temperature of about 65 to 120 ⁰ C for about 1 to 24 hours and on B. 9 to 1 part (s) by weight, based on the inhibitor, of one of the following sulfur compounds: Ferric sulfide, thiourea and its aliphatic homologues, aliphatic sulfides, alkali thiocyanates, aliphatic thiocyanates, Thio acids, mercaptothiazolines, mercaptans or mixtures of two or more compounds from the same group or from different groups of sulfur compounds. 2. Corrosion inhibitor according to claim 1, characterized in that component A as 10 to 200% solution is present in a glycol. 3. Corrosion inhibitor according to claim 1 or 2, characterized in that it is about 10 to about Percentage by weight of a wetting agent, based on the inhibitor. 4. Corrosion inhibitor according to claim 2, characterized by an additional content of Part by weight of an acetylenic alcohol containing up to 20 carbon atoms for 6 to 19 parts by weight of the inhibitor. 809 630/1027 10.68 © Bundesdruckerei Berlin