CA1327446C - Polyalkylenepolyamines as corrosion inhibitors - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
A corrosion inhibiting polyalkylenepolyamine composition comprising a mixture of (a) at least one C-alkyl-ethylene diamine, and (b) at least one di-(C-alkyl)-diethylenetriamine or at least one di-(C-alkyl)-piperazine or a mixture thereof;
wherein each C-alkyl group on the ethylene diamine, diethylenetriamine and piperazine independently contains from 10 to 28 carbon atoms. Methods for preparing this composition are also disclosed, as well as methods for its use in inhibiting corrosion of corrodible metals.

Description

1327~46 01 POLYALKYLENEPOLYAMINES AS COP~ROSION INHIsIToRs BA~KGROUND OF T~E INVENTION
This invention relates to a hydrocarhon-soluble S composition which is useful in inhibiting the corrosion of a corrodible metal material. ~ore particularly, this invention relates to a hydrocarbon-soluble polyalkylene-polyamine composition comprising a mixture of (a) at least one C-alkyl-ethylene diamine and (b) at least one di-(C-alkyl)-diethylenetriamine or at least one di-(C-alkyl)piperazine or mixtures thereof;
wherein each C-alkyl qroUP on the ethylene diamine, diethylenetriamine and pyrazine independently contains from l0 to 28 carhon atoms. This invention also relates to methods for preparing this composition. The invention further relates to a method of inhihiting corrosion in corrodible metals.
Corrosion inhibition in acid systems has been the subject of considerable interest in recent years. In ~ industrial cleaning operations, where a~ueous solutions of acid serve to remove scale and other deposits from metal-lic surfaces of industrial equipment, the inhibitors are used to reduce acid attack on the metals of construction ~, during the cleaning operations. In processing operations ; 25 where some acid is present or may be qenerated, inhibitors J are introduced to reduce the corrosiveness of the acid.
In oil well operations, corrosion inhibitors are intro-duced during various treatment staqes and during secondary recovery operations. In all these operations, the corro-sion inhibitor is in a form which is dispersible and pre-ferably miscible in the liquid medium of the particular system.
- Since the industrial eauipment being protected by the inhibitor is often of considerable value or is often difficult an~ expensive to replace, significant -~ importance has been given to the development of new and improved corrosion inhibitors. One area of such interest has been the organic inhihitors such as the amines, ,, , ~ 40 , , , . ,: .

6:

Ol ketones, sulfides, acetylenic alcohols and the like. In respect to the amines or to their acid salts commonly formed in the acidic systems, fatty amines havin~ one or more amine groups have been recognized as effective -05 inhibitors. Rosin amines have also been used as corro-sion inhibitors as have their oxyalkylated derivatives.In addition, various polymeric resins with amine func-tionalities have been used to some extent. rlOst of the commercial filminq amine corrosion inhibitors are reaction products of fatty acids with ethylene diamine, diethylenetriamine and hiqher polyamines, resulting in amidoamines and imidazolines.
U.S. Patent No. 3,770,377 discloses a method for preventinq corrosion of metals in an acidic environment by utilizinq a corrosion inhibitor which is the reaction product formed by reacting, in the liquid phase and under neutral conditions, at least one carbonyl compound and at least one amine containinq a plurality of primary or secondary amino qroups. Specific amines tauqht by this , patent include hexamethylene diamine and 1,8-diaminonaph-A thalene. Specific carbonyl compound.s employed include formaldehyde and cyclohexanone.
U.S. Patent No. 4,554,090 discloses a combina-tion corrosion and scale inhibitor composition comprisinq s 25 the reaction product of (a) a heterocyclic nitrogen-con-taininq compound selected from alkylpyridine, alkylpyrimi-dine, alkylimidazole, alkylimidazoline, quinoline and ^ quinaldine, (b) an aldehyde, and (c) a phosphoric acid constituent.
U.S. Patent No. 3,977,981 discloses a method for inhibiting corrosion of corrodible metals utilizing a 14-membered or 16-membered macrocyclic tetramine.
U.S. Patent No. 4,511,480 discloses a method of inhibitinq corrosion of ferrous metals by employing a phosphate ester of an oxyalkylated thiol.
U.S. Patent No. 4,089,789 discloses a method for inhibiting corrosion of ferrous metal in an acid system utilizinq an oxyaikylated phenolic inhibitor comprising 01 the reaction product of (a) an alkylene oxide and (b) a phenolic compound having two non-oxyalkylatable, saturated tertiaryamino alkylene groups.
U.S. Patent No. 4,388,214 discloses corrosion S inhibitors comprisin~ the reaction product of certain imidazolines or precursors thereof and elemental sulfur.
U.S. Patent No. 4,084,971 discloses a metal protectinq composition comprising zinc, a partially hydro-lyzed organic silicate, and a fatty acid amidoamine formed by the interaction of an ethylenically unsaturated fatty acid and an alkylene polyamine containing two primary amine qroups and at least one secondary amine group wherein the alkylene ~roup contains about 2 to 5 carbon atoms.
U.S. Patent No. 3,766,053 discloses a method for preventing corrosion utilizinq an imidazoline compound formed from the reaction of a naphthenic acid and dipro-pylene triamine.
U.S. Patent No. 3,728,277 discloses a corrosion , inhibiting composition comprising a mixture of (a) an ; imidazoline or oxazoline salt of a lonq chain fatty acid and (b) a salt of a lon~ chain aliphatic amido amine and a lon~ chain aliphatic carboxylic acid.
U.S. Patent No. 2,940,927 discloses a method of inhibitin~ corrosion of ferrous metals utilizing the final ~, reaction product ohtained by first condensing two moles of a polyamine selected from tetraethylene pentamine, triethylene tetramine, diethylene triamine and ethylene -~ diamine with one mole of a dicarboxylic acid to provide an intermediate bis-imidazoline reaction product, which is then contacted with 1 to 4 moles of ethylene oxide.
~1 U.S. Patent No. 4,344,861 discloses a method of inhibitin~ corrosion of metals utilizing the bis-amide reaction product of about one e~uivalent of a dicarboxylic acid and about one mole ratio of an amine. Amon~ the amines contemplated for use in this method include N-alkyl and N-alkenyl alkylene diamines, wherein the alkylene ~roup contains from 2 to about 10 carbon atoms. Also --' .j ~
1327~,4~193~-179~ `
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; 01 contemplated are terminally N-suh~tituted polyethylene polyamines, such as diethylenetriamine, triethylenetetra-mine, tetraethylene~entamine and pentaethylene hexamine.
The preparation of ethylene diamine and other 05 ethylene polyamines is well known in the art. For exam-ple, U.S. Patent No. 1,832,534 disclo~e~ the preparation of ethylene diamine by reactin~ ethylene dichloride with aqueous ammonia at a temPerature of about 110C and a pressure of about 10 atmospheres.
Similarly, U.S. Patent No. 2,049,467 describes a procedure for makin4 ethylen~ polyamine~ wh~in ethylene dichloride and a dilute aqueous solution o~ ammonia are heated und~r ~ressure at temperatures of from 120C to 300C.
~i lS U.~. Patent No. 2,769,841 discloses an improve-~ ment in the preparation of ethylene polyamines and p~ly-:`? ethylene polyamines by addinn die~hylenetriamine to a starting mixture of ethylene dichloride and an anueous ~i solution of ammonia, to reduce the formation of diethyl-~'? ~ enetriamine and increase the formation of higher poly-ethylene polyamines.
U.S, Patent No. 3,751,474 disclo~ea the prepara-~; tion of relatively hinh molecular wei~ht ~olyethylene s polyamines by the reaction of ethylene dichloride and s 25 a~ueous ammonia, using a mole eatio of ammonia to ethylene dichloride of more than 2.6 to 1.
U,S. Patent No. 4,123,462 describes a process for aminatin~ aliphatic alkane derivatives containin~ from one to six carbon atoms with ammonia in the presence of a solid nickel-rhenium catalyst, wherein said alkane deriva-tives are selected ~rom the lo~er alkanemono-ol~, lower alkane diols, lower alkanolamines, and mixt~lres t~hereof.
~anadian Patent No. 1,197,263 describes a continuous process for the manufacture of ethylenediamine from the ethanolamine mixture Produced by reactin~ ethylene oxide with ammonia hy providing a con-tinuous monoethanolamine recycle stream to a reaction zone comprising a solid amination catalyst.
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East German Patent No. 149,509 describes a pro-cess for the manufacture of a mixture of polyethylene-amines from ethylene oxide and ammonia at high pressure by stepwise non-catalytic reaction with ammonia to produce 05 ethanolamine followed by catalytic reaction with ammonia to produce the polyethyleneamines.
U.S. Patent No. 4,112,050 discloses a process for removin~ CO2 from gaseous feeds using sterically hin-! ~ered amines. Among the many compounds disclosed is , 10 2,2,5,5-tetramethyld;ethylenetriamine (Col. 15, lines 27-31).
U.S. Patent No. 4,293,682 discloses ~riamines of the general formula:
, ~ .
Me R3 Me ., H2N-c-cE~2-N-cH2-cl NH2 , Rl R2 ~~ ~ where Rl and R2 can be lower alkyl and R3 can be hydrogen.
The polyamines are useful as epoxy curing agents for poly-epoxides.
;; U.S. Patent No. 4,629,752 discloses particular hi~hly hranched chain polyalkylenepolyamines as startinq materials for polysubstituted piperazinones, useful as U.V. stabilizers for polymers. See, for example, struc-ture (IX) in Column 12, lines 41-47. These structures ~ require that the carbon adjacent to the primary amines be -i disubstituted.
Kempter and r~oSer in J. Prakt. Chem. 34(1-4), 104-11 (1966), CA 66:28324v describe the preparation of even-numbered 1,2-diamines from chromatoqraphically pure even-numbered fatty acids. This procedure involves pre-paring the 2-bromo-acid, reacting it with thionyl chloride ` 35 and then ammonia to produce the 2-bromo-amide, reactin~
the amide with 40-80 equivalents of aqueous ammonia to produce the 2-amino-amide and then reducinq this product , . , , .

Ol with lithium aluminum hydride. Aliphatic 1,2-diamines up to Cl~ are disclosed.
~.S. Patent No. 2,736,658 discloses aliphatic diamines of the structure:

H
P~-N-(cH2)x-NH2 wherein R represents an ali~hatic or alicyclic carbon chain attached to nitrogen of ~rom 8-22 carbon atoms and x is a number from 2-10. Preferably, x is 3. These compounds are described as corrosion inhibitors, the effectiveness increasing ~reatly when the diamines are employed in the form of their fatty or rosin acid salts.
Prior art corrosion inhibitors are generally N-alkyl-amines or polyamines, wherein the alkyl group is typically in the deterqent ran~e. We have now surpris-inqly discovered that when this alkyl qroup is attached to ~U carbon rather than nitro~en, polyalkylenepolyamine ~ compositions havinq improved corrosion inhibiting -~ characteristics are obtained.
SUMMARY OF THE INVENTION
; The present invention provides a hydrocarbon-; 25 soluble, corrosion inhibiting polyalkylenepolyamine compo-sition comprising a mixture of (a) at least one C-alkyl-ethylene diamine and (b) at least one di-(C-alkyl)-diethylenetriamine or at least one di-(C-alkyl)-piperazine, or a mixture thereof; wherein each C-alkyl group on the ~` 30 ethylene Aiamine, diethylenetriamine and piperazine independently contains from 10 to 28 carbon atoms.
The present invention also provides a corrosion inhibiting composition comprising the polyalkylenepoly-amine product obtained by the reaction of a 1,2-dihalo-alkane having from 12 to 30 carbon atoms and ammonia.
The present invention additionally provides a corrosion inhibiting composition comprising the poly-alkylenepolyamine product obtained by the reaction of a l-epoxyalkane having from 12 to 30 carbon atoms and ,, - ~ .

_7_ ~327446 l ammonia, in the presence of an amination catalyst and hydrogen.
The present invention further provides a method of inhibitin~ corrosion of a corrodible metal material 05 which comprises contacting the metal material with an effective amount of the corrosion inhibitor composition of the invention.
The present invention is also concerned with a method of inhibitin~ corrosion of a corrodible metal mate-rial in or around a well through which a corrosive fluid ` is produced, which comprises contacting the metal material with an effective amount oE the corrosion inhibitor compo-sition of the invention.
Amon~ other factors, the present invention is based on our discovery that a mixture of C-alkyl-ethylene ` diamines and di-tC-alkyl)-diethylenetriamines and/or ... .
di-(C-alkyl)-piperazines, wherein each alkyl group independently contains from 10 to 28 carbon atoms, are outstandin~ corrosion inhibitors in various environ-ments. More particularly, the invention is based, in part, on the discovery that formulations of the presently described polyamines qive greater than 90% inhibition of both CO2 and H2S corrosion in the industry-standard wheel test with NACE hrine (National Association of Corrosion Enqineers), under both continuous and film persistence ., '~ test modes. Moreover, the polyamine products of this invention show superior inhihition of CO2 corrosion in film persistence wheel tests at low treatment levels (500-2,000 ppm) when compared wlth known commercial corrosion inhibitors, such as Tretolite KP310, Nalco ~f ` Visco~4910 and Nalco Visco 945.
DETAILED-DESCRIPTION OF THE INVENTION
The Polyalkylenepolyamines The polyalkylenepolyamine composition of this invention comprises a mixture of (a) at least one C-alkyl-~- ethylene diamine and (b) at least one di-(C-alkyl)-diethylenetriamine or at least one di-(C-alkyl)-piperazine, or a mixture thereof;

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' ' -8- ~ 32~ 446 wherein each C-alkyl group on the ethylene diamine, diethylenetriamine and piperazine independently contains from 10 to 28 carbon atoms. Generall~, the composition of this invention will contain qreater than 1% of component (b), and preferably greater than 5% of component (b), relative to component (a). The ratio of component (b) to component (a) will preferably range from about 0.05:1 to about 20:1.
Preferably the C-alkyl groups on the ethylene diamine, diethylenetriamine and piperazine will each con-tain from 14 to 22 carbon atoms, and more preferably, from 18 to 22 carbon atoms.
The polyalkylenepolyamine composition of this invention contains a mixture of compounds. This mixture includes at least one C-alkyl-ethylene diamine of Structure 1, wherein R iR an alkyl group containing 10 to 28 carbon atoms.

R-C~i_CH2-N1~2 ( 1 ) ;!O
NH

The composition of this invention also includes at least one di-(C-alkyl)-diethylenetriamine or a di-(C-alkyl)-piperazine, or a mixture thereof. Generally, at least one di-(C-alkyl)-diethylenetriamine of Structure 2 is present.

Rl H IR2 30 H2N-CH-CH-N-CH-CH-NH2 (2) In Structure 2, Rl, R2, R3 and R4 individually 3S may be hydrogen or alkyl of 10 to 28 carbon atoms, pro-vided that two of the Rl, R2, R3 and R4 groups are hydro-gen and two of the Rl, R2, R3 and R4 groups are alkyl.
These di-(C-alkyl)-diethylenetriamines generally include compounds substituted at the 2 and 5 position, at ~0 9 1327~46 01 the 2 and 6 positions, and at the 3 and 5 positions. The compounds of Structure 2 can also he described as di-(C-alkyl)-2,2'-diaminodiethylamines.
A cyclized di-(C-alkyl) component may also be 05 present, in addition to, or instead o~, the di-(C-alkyl)-diethylenetriamines. Generally, one or both of the di-(C-alkyl) piperazines of Structure 3 is present:

H-N'' 2 - N_ ~ C~-CH-'' I I

In Structure 3, R5 is alkyl of 10 to 28 carbon atoms and one of the R6 and R7 groups is hydrogen and the other of the R6 and R7 groups is alkyl having a chain lenqth of from 10 to 28 carbon atoms. These compounds may be ~ described as 2,5- and 2,6-dialkylpiperazines.
- ~ It is believed that the above-described dialkyl compounds of Structures 2 and 3 are especially advantage-ous in controlling corrosion. Preferred alkyl groups are derived from the correspondinq linear alpha-olefins.
Even-numbered alpha-olephins are preferred. Particularly preferred are the compounds of Structures 1, 2 and 3 wherein the alkyl group contains 14-22 carbon atoms, most preferably 18-22 carbon atoms. Polyalkylenepolyamines having a mixture of alkyl groups containing more than one carbon chain length are especially preferred, as they have increased solubility, lower melting points and lower pour points.
By the term "polyalkylenepolyamine" is meant a mixture of compounds including the alkyl diamines of -~ Structure 1, the higher dialkylpolya~ines of Structures 2 - 15 and 3, and higher polyalkylenepolyamine oligomers. The alkyl chain can be linear or branched. Although Structures 1, 2 and 3 show primary and secondary amine groups, these amine groups can be substituted with one or , -i 01 more alkyl or aminoalkyl groups. These compounds are also encompassed hy the term "polyalkylenepolyamine". As referred to herein, the term "polyamine" is also used to mean "polyalkylenepolyamine".
S These polyalkylpolyamines can he present as either the free base or as a salt thereof, such as a hydrochloride salt. Thus, the term "polyalkylenepolyamine"
is also meant to include the free base, the ammonium salt form, or mixtures of the two.
I As used herein, the term "C-alkyl" refers to an alkyl group directly bonded to carbon, and the term "di-(C-alkyl)" refers to two alkyl groups directly bonded to two different carbon atoms. This usage of "C-alkyl" is similar to the expression "N-alkyl", meaning an alkyl group directly bonded to nitrogen.
Preparation of Polyalkylenepolyamine The corrosion inhibiting composition of this - invention can be prepared by a variety of methods. Suit-able methods for preparation of this composition include, but are not limited to the following: reaction of a 1,2-dihalo-(C12-C30)alkane with ammonia, in which the halogen may be chlorine, bromine or iodine; reaction of a l-epoxy-(C12-C30)alkane with ammonia in the presence of a suitable catalyst; reaction of a l-amino, 2-(C12-C30)alkanol or 1-amino, di-~2-(C12-C30)alkanol] or mixtures thereof with ammonia in the presence of a suitable catalyst; reaction of a 1,2-(C12-C30) alkanediol with ammonia in the presence of a suitable catalyst; reaction of a (C10-C28) C-alkylaziridine with ammonia. A critical factor in - determining what constitutes a suitable method for prepar-ing the present composition is that the process must pro-vide for the formation of the above-described di-(C-alkyl) - component, that is, component (b), in addition to the C-alkyl ethylene diamine of component (a).
Preparation from 1,2-Dihaloalkanes - A preferred method of preparing the present composition is by reacting a 1,2-dihalo-(C12-C30) alkane with ammonia, preferably by the reaction of a ,~

01 1,2-dichloroalkane and ammonia. Although it is understood that any of the l,2-dihaloalkanes may be employed, the 1,2-dichloroalkanes will be discussed as representative.
In general, the 1,2-dichloroalkane will contain S from 12 to 30 carbon atoms, preferably from 16 to 24 car-bon atoms, and more preferably, from 20 to 24 carbon atoms. The 1,2-dichloroalkane employed may be a single carbon number or a mixture of several carbon numbers. The alkane may be branched or linear.
l The 1,2-dichloroalkane may be prepared from readily available alpha olefin feedstocks. Suitable alpha olefins are those containing about 12 to 30 carbon atoms, preferably about 16 to 24 carbon atoms, and more prefera-bly, about 20 to 24 carbon atoms. These alpha olefins are normally obtained by the crackinq of wax or from the ethylene growth reaction. A particularly useful alpha olefin is the (C20-C24)-alpha olefin obtained from the ethylene growth reaction.
The alpha olefin is converted to the 1,2-dichlo-roalkane by reaction of the olefin with molecular chlorine in the presence of a free radical scavenger, such as ferric chloride. The reaction is generally carried out at a temperature in the range of about -15C to about +25C.
The reaction pressure is qenerally ambient, although posi-tive pressures in the range of 0 to ~5 psi may be employed.
The reaction is normally run in the presence of a solvent, such as carbon tetrachloride, or cyclohexane. The reac-tion time is generally from 0.5 to 2 hours. The resulting 1,2-dichloroalkane is then isolated from the reaction ~i mixture using conventional techniques. In similar fashion, the alpha olefin may be reacted with molecular bromine or molecular iodine to form the 1,2-dibromoalkane or the 1,2-diiodoalkane.
The polyalkylenepolyamine products of the-~
invention may be prepared by amination of the appropriate ` 1,2-dichloroalkane with ammonia. The molar ratio of ammo-nia to 1,2-dichloroalkane will normally range from about 2:1 to 100:1, and preferably from about 4:1 to 50:1. The 01 most preferred ratio is about 5:1 to 20:1.
Although the reaction of 1,2-dichloroalkane and ammonia may be effectively carried out without a solvent, it is generally preferable to run the reaction in the 05 presence of an organic solvent. Contemplated solvents are those polar organic solvents which are inert to the reac-tants under the presently described reaction conditions.
~ Especially suitable solvents are the alkanols, such as } isopropanol. The preferred solvent is alkanol. The weight ratio of ethanol to ammonia will generally range from about 50:5~ to 90:10, and preferahly from about 60:40 to 80:20.
The amination reaction will qenerally be carried out under substantially anhydrous conditions. It IS has been found that the relatively hiqh carbon number 1,2-dichloroalkanes employed herein do not readily form the polyalkylenepolyamine products of the invention in the ` presence of aqueous ammonia. This is in marked contrast to the known prior art use of a~ueous ammonia conditions in the conventional preparation of lower alkylene poly-aminés, such as polyethylenepolyamine.
The presently described reaction of 1,2-dichlo--~ roalkane and ammonia is normally carried out at a tempera-~ ture in the ranqe of about 100C to 250C, preferably in -l 25 the ranqe of about 160C to 230C, and most preferably in the range of about 180C to 200C. The reaction pressure is generally in the range of about 500 to 3,000 psi, and preferably about 800 to 1,500 psi. The reaction will ' normally proceed over a period of about 0.5 to 18 hours, although longer reaction times may be employed, depending upon the temperature and ammonia concentration.
At the termination of the reaction, the poly-alkylenepolyamine product is generally in a polyalkylene-polyamine hydrochloride form. If the free base is desired, ~; 35 neutralization may be effected by addition of a strong base, such as calcium hydroxide, sodium hydroxide, potassium hydroxide, and the like. The salt formed from the neutralization may be easily separated from the .:

-13- 132~446 01 or~anic free base. Typically, about 15% vinyl chloride side is product is produced usin~ this process. Reaction of the remainin~ chloride products with sodium metal is advantageous in using the resulting composition as 05 corrosion inhibitors. The isomer distribution does not significantly chan~e after reaction with sodium metal.
~justing the Hydrophobic-T~ydrophilic Ratio Advantageously, the hydrophobic-hydrophilic ratio and nitrogen content of the polyalkylenepolyamine product can be readily adjusted hy the addition of various amounts of ethylene dichloride, ethylene diamine or a hiqher polyethylenepolyamine, such as diethylenetriamine, durin~ the reaction of the 1,2-dichloroalkane and ammonia. The amount of ethylene dichloride, ethylene diamine or higher polyethylenepolyamine which may be reacted with the 1,2-dichloroalkane and ammonia will ; generally range from about 1 to 50 weight percent, and preferably from about 10 to 2n weight percent.
Preparation from l-Epoxyalkane A second preferred method of preparing the poly-alkylenepolyamines of the invention is by reaction of a l-epoxyalkane with ammonia in the presence of a suitable amination catalyst. In general, the l-epoxyalkane will contain from 12 to 30 carbon atoms, preferably from 16 to 24 carbon atoms, and more preferably, from 20 to 24 carbon atoms. The l-epoxyalkane employed may be a sin~le carbon number or a mixture of several carbon numbers. The alkane - may be branched or linear.
The l-epoxyalkane may be prepared from readily 3 available alpha-olefin feedstocks. As discussed above, suitable alpha-olefins are those containing about 12 to 30 carbon atoms, preferably about 16 to 24 carbon atoms, and more preferably, about 20 to 24 carbon atoms. These alpha-olefins are normally obtained by the cracking of wax or from the ethylene growth reaction. A particularly useful alpha-olefin is the (C20-C24)-alpha-olefin obtained from the ethylene qrowth reaction.

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Ol The alpha-olefin is converted to the l-epoxy-alkane by reaction of the olefin with a peracid such as performic acid, peracetic acid, perpropionic acid, and the like according to procedures well-known in the art.
S The polyalkylenepolyamine composition of the invention can be prepared by amination of the appropriate l-epoxyalkane with ammonia in the presence of a suitable catalyst and hydrogen. The molar ratio of ammonia to l-epoxyalkane affects the molecular weiqht distribution of the final polyalkylenepolyamine product and will normally ranqe from about 2:1 to 100:1 and preferably from about 8:1 to 50:1. Reaction of ammonia with the l-epoxyalkane to form a mixture of mono- di- and tri-alkanolamines takes place in the presence or absence of a catalyst in the temperature range 100-200C. Further reaction of the alkanolamines with ammonia to form the instant polyalkyl-enepolyamines requires a catalyst under hydrogen pressure and takes place in the temperature range 120-230C. The ' two reactions may be carried out in separate reaction zones, or together in the presence of hydrogen and the catalyst.
The presently described reaction of l-epoxy-alkane and ammonia is normally carried out in a single reactor at a temperature in the range of about 100 to 250C, preferably in the range of about 150 to 230C and , most preferably in the range of about 160 to 190C. The reaction pressure is generally in the range of about 500 to 3,000 psi, and preferably between about 500 to 1,500 psi. The reaction is normally charged at room temperature with hydrogen qas to a pressure of about 25 to 400 psi, and preferably to a pressure of about 100 to 300 psi. The catalyst employed in the reaction may be either supported ' or unsupported, and is generally present in an amount - equal to about 0.1~ to 30% of the weight of l-epoxyalkane, and preferahly 1% to 10% of the weiqht of l-epoxyalkane.
The reaction will normally proceed over a period of ahout ` 1 hour to 20 hours. The resulting polyalkylenepolyamine ' ,. . ~ .
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01 is isolated simply by flashin~ the volatile hydro~en, ammonia and water and filtering off the catalyst.
Alternatively, the reaction can be carried~out in two separate steps. The mixture of mono-, di- and tri-05 alkanolamines obtained from reaction of l-epoxyalkane with ammonia at an ammonia to l-epoxyalkane molar ratio between ~ 2:1 and 100:1 and preferably between 8:1 and 50:1 can be ; isolated and used in place of the l-epoxyalkane followin~
the procedure above.
i lO It is also envisioned that the reaction may be ~t` carried Ol~t in a continuous fashion with similar ratios of ammonia, l-epoxyalkane and hydrogen passing in a plu~-flow reactor over a bed of solid catalyst. This continuous process may also allow for separate reaction zones for IS (1) non-catalytic conversion of the l-epoxyalkane to alkanolamines mixture, for example in a preheater se~ment of the continuous reaction unit, and (2) catalytic amina-tion of the alkanolamines mixture to polyalkylenepoly-~! amines.
,~J Amination catalysts for converting alcohols to amines are known in the art and include nickel-containin~
and cobalt-containing catalysts. Preferred catalysts ~t~ include Raney Nickel, nickel chromite, supported cobalt-catalysts such as Harshaw-Filtrol Co-0138E, supported nickel-rhenium catalysts such as that described in U.S.
Patent No. 4,111,840, and supported nickel catalysts such as Harshaw-Filtrol Ni5136P. Most preferred are supported cobalt and supported nickel-rhenium catalysts.
Adjustin~ the Hydrophobic-Hydrophilic Ratio ;-~ Advanta~eously, the hydrophobic-hydrophilic ;~ ratio and nitro~en content of the polyalkylenepolyamine product can be readily adjusted by the addition of various amounts of ethylene diamene or a hi~her polyethylenepoly-amine durin~ the reaction of the l-epoxyalkane and ammonia. The amount of ethylene diamine or hi~her polyethylenepolyamine which may be reacted with the l-epoxyalkane and ammonia will ~enerally ran~e from about . , .

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13274~6 Ol 1 to 50 weight percent, and preferably from about 10 to 20 weight percent.
Corrosion Inhibition The polyalkylenepolyamines of this invention are 05 surprisinqly qood corrosion inhibitors. In comparison with commercial corrosion inhibitors, they show much superior performance.
For use as corrosion inhibitors, the polyamines of the invention are applied to the metal surfaces to be protected in a variety of ways known to the art. For example, a dilute hydrocarbon solution of the polyamine ; may be contacted with the metal to be protected, usin~
methods such as dipping, spraying, wiping, and the like.
- For this method of ap~lication, solutions of about 0.1 to 10~, preferably from about 0.2 to 1%, by weight of polyalkylene-polyamine, or mixture of polyalkylene-polyamine and other active corrosion inhibiting agents, are employed.
Alternatively, oil-soluble, water-dispersible ~ formulations of the present polyamines, or mixtures of the polyamines and other active corrosion inhibiting agents, can be added to a corrosive aqueous environment. In this method of application, sufficient amounts of polyamine, or mixture of the polyamine and other active corrosion inhibiting aqents, are added to give from about l to l,000 ppm, preferably from 10 to S00 ppm, of active corro-sion inhibitor in the final solution for continuous methods of treatment. For batch treatment methods, the level of corrosion inhibiting agents is qenerally between 500 and 25,000 ppm, preferably between l,000 and 10,000 ppm.
Generally, corrosion inhibitors are formulated with other components for corrosion inhibiting applica-tions.
Preferably, the corrosion inhibiting poly-alkylenepolyamine composition of the present invention will be combined with one or more dimer/trimer acids to provide a formulated product. Dimer/trimer acids are , 01 well-known in the art and are typically derived from~fatty acids. Examples of dimer/trimer acids include Empol 1024, Empol 1041, Empol 1052, obtained from Emery Chemicals.
In addition to the polyalkylenepolyamine of the S invention and the dimer/trimer acid, corrosion inhibiting formulations may also contain one or more surfactants, one or more alcohols and a hydrocarbon solvent. The surfac-tant employed may be ionic or nonionic in nature. Gener-j ally, nonionic surfactants are preferred. Typical nonionic surfactants include ethoxylated nonylphenols such as Igepal C0-630, Igepal CO-710, and ethoxylated fatty alcohols such as Tergitol 15-S-9. The hydrocarbon solvent may be any of the known solvents, such as kerosene, diesel fuel, paint thinner, toluene, lubricating oil, and similar materials. A typical hydrocarbon solvent is kerosene.
Isopropanol is a typical alcohol.
Generally, the active corrosion inhibiting agents will be combined with a solvent and a surface-active agent to produce a concentrated solution of the ~ corrosion inhibitor. In this solution, the polyamine, or mixture of the polyamine and other active corrosion inhibiting agents, will be present in amounts ranging from about 10 to 60%, preferably about 30 to 50%, by weight.
. The amount of solvent present is from about 30 to 80%, and the amount of surfactant is about 1 to 20%, by weight.
This concentrated formulation is then diluted to the desired concentration of the final solution.
A typical oil-soluble, water-dispersible formu-lation will contain about 15 to 30% of the present polyalkylene-polyamine, about 15 to 30% of a dimer/trimer acid, about 1 to 10% of a nonionic surfactant, about 25 to 75% of a hydrocarbon solvent, such as kerosene, and about 0 to 5~ of an alcohol, such as isopropanol.
Oil-soluble, water-dispersible formulations of the present polyamines are particularly useful in brine!CO2 or brine/~2S environments, such as encountered in oil wells, especially oil wells employing secondary oil recovery techniques.
' ~. ~ r~ na~<

~^~

~j Ol In standard wheel tests using NACE brine at `! 90C, tested in both saturated CO2 solution and in 500 ppm H2S, formulations of the ~olyamines of the present inven-tion provided corrosion protection of greater than 90~
3 ~5 over the treatment range of 20 to lO0 ppm in continuous tests and 2,000 to lO,000 ppm in film persistence tests.
For example, side-by-side film persistence tests in CO2 saturated N~CE brine were carried out at a 2,000 ppm treatment level. The polyamines of the present inven-lO tion provided 96% corrosion inhibition whereas the commer-cial corrosion inhibitor, Nalco Visco 945, provided only .82% corrosion inhibition.
~oreover, when film persistence tests in CO2 saturated NACE brine were carried out at lower treatment levels, formulations of the polyamines of the present invention continued to provide greater than 90% corrosion inhibition at treatment levels as low as 500 ppm, whereas the commercial corrosion inhibitors Tretolite KP310 and ~ Nalco Visco 4910 failed to provide at least 90% corrosion -~ ~ inhibition at treatment levels lower than 1,000 ppm and 5,000 ppm, respectively. Tretolite KP310, available from Petrolite Corporation, is described as a liquid oil-sol~
~j uble organic film forming inhibitor effective against `~ corrosion caused by H2S, CO2, and organic and mineral , ~.
acids. Nalco Visco 4910 and Nalco Visco 945, available from Nalco Chemical Company, are described as oil-soluble, water-dispersible corrosion inhibitors, formulated to control sweet and sour corrosion.
i It has also heen found that formulations of the .- polyalkylenepolyamines of the present invention containing the di-(C-alkyl)-diethylenetriamine and/or di-(C-alkyl)-piperazine compounds show improved adhesion to metal surfaces. These formulated products were observed to visibly stick to mild steel coupons more tenaciously than commercial formulated products, such as Nalco 945.
The following examples are provided to illus-trate the invention in accordance with the principles of this invention but are not to be construed as limiting the , 1 .

- 1327~4~

01 invention in any way except as lndicated hy the appended claim.s.
EXAMPLES
Example 1 S Preparation of 1,2-dichloro(C20-C24)alkane The alpha olefin used in this example was Gulftene~20-24, a linear C20-C24 alpha olefin fraction obtained from Chevron Chemical Company.
To a l-liter autoclave equipped with an air-drive stirrer, freon coolin~ coil system, nitro~en purge lines and a dip tube hooked up to a chlorine gas lecture bottle was added 300 g Gulftene 20-24, 600 g car-bon tetrachloride, and 6 g anhydrous FeC13. The mixture was stirred at 750 to 1000 rpm, purged with nitrogen and cooled to 0C. The nitrogen purge was then discontinued, and chlorine gas was added gradually over the course of 35 minutes, keeping the temperature between 0C to 5C.
Upon completion of the chlorine addition, nitrogen was purged through the solution for 1 hour to remove any unreacted chlorine gas. The crude reaction mixture was washed with 400 ml of 5 weight percent NaOH, followed by two water washes, after which the organic phase was x separated and filtered. The carbon tetrachloride solvent ' was removed on a rotary evaporator to yield 360 g of crude f product containing 19.0 weight percent C1. lH NMR anal-ysis of the product shows no evidence of any olefinic protons in the re~ion 4.6 to 6.0 ppm, where the olefinic ~; proton resonances of the starting alpha olefin appear, and shows a clear multiplet pattern in the region 3.6 to 4.1 ppm, characteristic of the vicinal dichloride func-tionality, thus verifying complete conversion of the alpha olefin to 1,2-dichloride.
Example 2 ,':
Preparation of Poly(C20-C24)alkylenepolyamines To a 300-cc, 316 stainless steel autoclave ` equipped with an Athena temperature controller and an air-drive stirrer were added 12.9 g of the dichloride from Example 1 and 54 ~ absolute ethanol. The autoclave was ' --~o--0l sealed, and 23.1 g ammonia was added, using a HOKE bomb to carry out the transfer between the ammonia cylinder and the autoclave. The stirrer was turned on and temperature raised to 195C over the course of 20 minutes. The reaction 05 was carried out for 2 hours at 195C and 900 psi, and then cooled to room temperature. The autoclave was vented, the crude product removed with methylene chloride and evapo-rated to dryness. The resulting solid was taken up in 150 ml of methylene chloride, washed with 200 ml 5% NaOH, twice with distilled water and filtered. The methylene chloride was then removed on a rotary evaporator at 55C
under 3 mm Hg vacuum to a constant weight. 9.97 g of crude product, melting at 55-62C, were obtained, which by - elemental analysis contained 77.01~ C, 13.35% ~, 4.78~ N, and 3.31% Cl. 1H NrqR analysis of this product showed, in addition to some residual resonances in the region 3.6 to 4.1 ppm from unreacted starting material, complex new multiplets in the region 2.4 to 2.9 ppm, characteristic of a mixture of vicinal diamino functional qroups. Some resonances in the region 5.0 to 6.1 ppm also appeared, and were confirmed by independent synthesis and analysis to be caused by small amounts of vinyl chloride elimination , product. ~ased on the % Cl in the crude product, and on the ratio of vinyl chloride to dichloride starting mate-rial as obtained from the lH N~1R data, the conversion of ~ the starting dichloride to product was calculated to be -~ 86% and selectivity of the converted product to polyamine versus vinyl chloride was 91%. Field ionization mass spectral (FI~1S) analysis of the product showed that 90% of the product was the monomeric C-alkyl-ethylene diamines, 9% of the product was the dimeric di-(C-alkyl) compounds, and that small amounts of higher oligomers were also - obtained.
- Examples 3-ll Preparations of Poly~C20-C24)alkylenepolyamines - Additional polyalkylenepolyamines were prepared using variations in reaction temperature, reaction time, - and reaction solvent from the procedure specified in .
., .

-01 Example 2. ~ith the exception of Example 3, all of these reactions produced reasonable yields of polyalkylenepoly-amines with various conversions and selectivities, calcu-lated as outlined in Example 2 and summarized in Table I
05 below. Example 3 is sigrlificant because it illustrates that polyalkylenepolyamines with large alkylene groups,such as C20-C24, cannot be prepared under the aqueous ammonia conditions used for traditional manufacture of polyethylene~olyamines.
I Table II shows the product distribution for the products of Examples 2, 9, 10 and 11. Table II demon-strates that, by varying reaction conditions, varying amounts of dimer and hi~her polyamines can be obtained.

i ~0 v , ' 4~6 C ~
1 ~ O u~ U) I
~ ~ ~ ~ a~
Z ~ o ~ s~ o _ ~q C
o o . . ~ ~ ~ ~ ~ dP ~ ~ dP
O ~ o oo ~ O u~ o ~
co ~ O 'O
~ ~ ~ ,~
g .c a)-~n o o o o o o o o o ,~
~ ~O ~ ~ o o o u~ o a~
.,, u~ ~, c ~ ~ 7 H r-l Q~-- O U~ O O 1~1IJ-) In 11'1 U~
O ~ ~_) ~) O ~ O
~ ~ ~-Q ~ h ~ ~ ~
i~ ~ E~.C ~ h rl O ~
o ~ C C ~ O ¦~ 0 0 0 CO
. ~ m ~ ~P O ~ ~ ~ ~ ,1 ~ ~ 3 ~ Z æ~ ~ ~o ~ U~ ~1 o a~ o r~ ~) I O t~ ) ~ ~ O ~ U~ C
æ ~ ;

, o o ., .L) ~ ~ ~0 0 ~0 ,~ o ~
u~ !r c c c c 2 h 2 ~
dP f~) C .C .C ~ O O O
H H H U~

X I O ~ ~
_~ In o u~ o u~
O O

. --23--., .
01 TABLE II(l) Polyalkylenepolyamine Product Distribution , NH3/
05 1,2-di-chloro-~.~. alkanes, Product Distribution Mole Ex. Ratio rlOnomer(2) Dimer(3) Trimer(4) Tetramer(5) 2 41.4 90 9 :~ . 1O 9 5.0 12 70 18 ~'. 10 7.8 7 32 35 26 11 10.6 28 63 8 ., .,., -- .
~ l5 (1) As determined by field ionization mass spectroscopy ~;, ( FIMS ) (2) C-alkyl ethylene diamine .~
~i (3) Di(C-alkyl)polyamine (4) Tri(C-alkyl)polyamine (5) Tetra(C-alkyl)polyamine :~ .
~; Fxample 12 ; Preparation of C20-C24 alkanolamines rqixturè
,. .
252 9 of 1-epoxy(C20-24)alkane~ obtained from Viking Chemical Company under th~ trade name "Vikalox 20-24", was added to a stirred, 1 gallon stainless steel autoclave`along with 503 g isopropanol and 840 g anhydrous ~. ammonia. This corresponds to an ammonia to epoxyalkane ; 30 mole ratio of 60:1. This mixture was heated at 150C at a pressure of 1,590 psi for 2 hours. Upon completion of the reaction, the crude alkanolamine was stripped of ammonia and isopropanol at 95C using a rotary evaporator with ~- 1 mm Hq vacuum.
- 35 The NMR spectrum of the product indicated complete conversion of the starting epoxide, and exhibited the following proton NMR resonances: multiplet at 2.45-2.58 anA a doublet of doublets at 2.83 and 2.87 ppm, .

, 1327~46 characteristic of the alkanolamine structures. Nitrogen analysis of the product was 3.58~.
From the theoretical nitrogen contents of pure monoalkanolamine (4.20~) and pure dialkanolamine (2.16%), the experimentally obtained nitro~en content is calculated to correspond to a mixture of approximately 70 monoalkanolamine and 30% dialkanolamine.
Examples 13-15 Additional C20-C24 alkanolamines mixtures were !~ prepared accordinq to the procedure in Example 12, except ; for the mole ratio of ammonia to epoxyalkane. The nitrogen contents and calculated mono-, di- and tri-alkanolamine contents are summarized in Table III below:

~t TABLE III
r Ammonia:
Epoxyalkane, % r1ono- % Di- ~ Tri-r~ole Experimental alkanol alkanol alkanol ; Ex. _ Ratio N, %_ amine amine amine i ~ 13 30:1 3.32 57 43 ; 14 10:1 2.73 28 72 15 5:1 1.77 - 55 45 These examples show that, at lower ammonia to ~3 25 epoxyalkane mole ratios, higher amounts of dimeric and t, higher alkanolamines are produced. These mixtures of - alkanolamines can be converted to polyalkylenepolyamines hy reaction with additional ammonia and an amination catalyst, as in Examples 19-21.
Example 16 Preparation of poly(C20-24)alkylenepolyamine . from l-epoxy(C20-24)alkane with Raney Nickel Catalyst Raney Nickel as obtained from Grace Davison i Chemical Company was dried and crushed to a fine powder 35 under an inert atmosphere prior to use. 3.0 y of 1-epoxy(C20-24)alkane, obtained from Vikinq Chemical Company under the trade name "Vikalo ~20-24" and 0.3 g dried Raney Nickel were combined in a 17 cc stainless steel microbomb ~ ~

. . .
01 under an inert atmosphere. 2.0 g anhydrous ammonia was weighed into the dry ice-acetone bath cooled microbomb, , ~! after which hydrogen gas was adde~ to a total reactor l pressure of 350 psi. The reaction was carried out at ~,J 05 200C for 4 hours. The microbomb was then coole~, vented, ~ and the crude product mixture dissolved in 50 cc warm ; chloroform and allowed to settle. The supernatant solution was decanted from the catalyst, and the chloroform stripped away on a rotary evaporator.
j 10 NrlR analysis of the product showed essentially 9~ complete conversion of the starting epoxide to a mixture of approximately 64~ poly(C20-24)alkylenepolyamine as evidenced hy its characteristic multiplets at 2.42-2.48, - 2.67 and doublet of doublets at 2.73 and 2.77 and 21%
~j 15 ;~ alkanolamines showing a multiplet at 2.45-2.58 and a -- doublet of doublets at 2.83 and 2.87 ppm. Elemental analysis indicated a nitro~en content of 4.01~.
Example 17 Preparation of poly(C20-24)alkylenepolyamine ~ from l-epoxy(C20-24)alkane with Cobalt Catalyst The same procedures were followed as in Example 16, except that the catalyst used in place of Raney Nickel was Co-0138E, a commercial supported cobalt catalyst obtained from Harshaw-Filtrol Company.
2S N~JR analysis of this reaction indicated complete conversion of the starting epoxide to a mixture of -9 approximately 81% poly(c2o-24)alkylenepolyamine and 17%
i alkanolamines as identified by the resonances indicated in the above examples. Elemental analysis of this product 30 indicated 3.73% N.
Example 18 , Preparation of poly(C20-24)alkylenepolyamine from l-epoxy(C20-24)alkane with Nickel Chromite Catalyst ~ - .
The same procedures were followed as in Example 35 16, except that the catalyst used in place of Raney Nickel was a commercial Nickel Chromite catalyst obtained from ALFA Products. This reaction was run for 6 hours, after which NMR analysis of the product indicated approximately :

, , .; .
01 52% poly(C20-24)alkylenepolyamine and 48~ alkanolamines as `. idsntified by the resonances indicated in the above examples.
~r, Example 19 05 Preparation of poly(C20-24)alkylenepolyamine from C20-24alkanolamines with Raney Nickel Catalyst The same procedures were followed as in Example 16, except that the C20-24alkanolamines mixture prepared as described in Example 12 was used in the place of ` I0 1-epoxy(C20-24)alkane as the startinq material, and the ', reaction was run for 28 hours. NMR analysis of this product indicated a mixture of approximately 79%
poly(C20-24)alkylenepolyamine and 6% alkanolamines.
- Example 20 ~i 15 Preparation of poly(C20-24)alkylenepolyamine x from C20-24alkane with Nickel Catalyst The same procedures were followed as in Example . 16 above, except that a commercial Harshaw-Filtrol Nickel :j ~` 5136P catalyst was used in place of Raney Nickel and the ~ reaction was run for 6 hours. Nl1R analysis of this product indicated a mixture of approximately 72~
`~ poly(C20-24)alkylenepolyamine and 28% alkanolamines as identified hy the resonances indicated in the above ~ examples.
;s 25 Example 21 Preparation of poly(C20-24)alkylenepolyamine ~ from C20-24alkanolamines with Nickel-Rhenium Catalyst -?
` The same procedures were followed as in Example 19 above, except that a Nickel-Rhenium supported on alpha alumina catalyst prepared according to the procedure in U.S. Patent No. 4,111,840 was use~ in place of Raney Nickel and the reaction was run for 6 hours. NMR
analysis of this product indicated a mixture of approx-imately 86% poly(C20-24)alkylenepolyamine and 14%
; 35 alkanolamines, as identified by the resonances indicated in the above examples. The melting point of this product was 61-72C. Field ionization mass spectral analysis of the product showed that 52% of the product was the ,, :' ~. .

- . :

:

.

01 monomeric C-alkylethylenediamine and 46% of the product was the dimeric di(C-alkyl) diethylenetriamine or di(C-alkyl) piperazine or mixtures of these.
Example 22 S Preparation of Copolymers of (C20-C24)alkylene-and ethylenepolyamines _ ~
In order to demonstrate that it is possible to increase the nitrogen content and thus vary hydrophilic/
hydrophobic properties of the product, polyalkylenepoly-10 amines containing a mixture of C20-C24 alkylene groups and ~ ethylene groups were prepared ~y using equal molar amounts !,i of ethylenediamine and 1,2-dichloro(C20-C24)alkane in the amination reaction.
To a 300-cc, 316 stainless steel autoclave l5 equipped with an Athena temperature controller and an air-drive stirrer were added 12.93 g of the dichloride from Example 1, 2.06 g ethylenediamine and 54 q absolute ~' ethanol. The autoclave was sealed, and 38 g ammonia was q added, using a HOKE bomb to carry out the transfer between the ammonia cylinder and the autoclave. The stirrer was turned on and temperature raised to 160C over the course of 20 minutes. The reaction was carried out for 4 hours at 160C and 850 psi, and then cooled to room temperature.
The autoclave was vented, the crude product removed with 25 methylene chloride, and evaporated to dryness. The resulting solid was taken up in 150 ml of methylene chlo-ride, washed with 200 ml 5% NaOH, twice with distilled water and filtered. The methylene chloride was then removed on a rotary evaporator at 55C under 3 mm Hg 30 vacuum to a constant weiqht. 10.94 g of crude product were obtained, which by elemental analysis contained 77.71% C, 13.26~ H, 5.39~ N, and 2.51% Cl. lH NMR
analysis of this product showed the same complex new multiplets in the reqion 2.4 to 2.9 ppm characteristic of 35 the polyamine product, as described in Example 2, onl~y these had a greater intensity relative to the polyamine products obtained with 100% C20-C24 alkylene qroups. This greater intensity corresponds to a qreater content of ., ~

:~ .

i , f_~ .

~ 1327446 ~^ -28-" 01 1,2-diaminoethylene linkaqes in the product. This lH NMR
result and the higher ~ N (5.39% versus 4.85% for Rxample 7 run under similar conditions without the addition of ethylenediamine) verify the incorporation of 05 ethylenediamine into the final polyalkylenepolyamine product mixture.
Example 23 Formulation of Poly(C20-C24)alkylenepolyamines for CO2 and H2S Corrosion Inhibition .~i ~, 10 It is well known in the art that filming amines are usually formulated with other active inqredi-.~5 ents and surfactants to produce a formulation which is ~' effective aqainst CO2 and E~2S corrosion in oil field , - environments. For the purposes of the corrosion tests .,7, 15 reported in Examples 24 and 26, the followin~ formulation of polyalkylenepolyamines was used for the polyamines of ;1; Examples 2-11:
;,.~.
- .
~ Formulation A
"''- ;~0 Inqredient __ Weiqht Percent .~
~, Polyalkylenepolyamine 16.4%
3 Empol 1052 Dimer/Trimer Acid 12.0%
-i Dodecylbenzenesulfonic Acid 1.6%
i- 25 Igepal C0630 Ethoxylated Nonylphenol 1.0%
Exxon HAN heavy aromatic naphtha 69.0%

- The following formulation of polyalkylene-~~ polyamines was used for the corrosion tests show in , 30 Example 25 using the polyamines of Example 21:
i Formulation B
, InqredientWeiqht Percent Polyalkylenepolyamine 15.0~ -Empol 1052 Dimer/Trimer Acid 13.2%
Dodecylbenzenesulfonic Acid 2.0~
Igepal C0630 Ethoxylated Nonylphenol 1.0%
~; Exxon HAN heavy aromatic naphtha68.8%

" .

, , ~ ^ ~

i 29 13274~6 Ol Exam~le 24 Wheel Test Evaluation of Poly(C20-C24)alkylenepolyamines as Corrosion Inhibitors for CO2 and H2S Corrosion n5 The wheel test is an industry-standard test procedure for evaluating corrosion inhibitors. This test is described in the National Association of Corrosion l Engineers (NACE) publication lDl82. The procedures 0l followed in this example are essentially the same as those ,!, 10 described in the NACE publication, and are summarized below.
The test fluids consisted of 90% synthetic brine as described in NACE publication lD182 and 10% deodorized kerosene. For CO2 corrosion tests, the brine was lS deaerated with nitrogen~ then saturated with CO2 by purging with CO2 gas at room temperature. For H2S corro-~ sion tests, H2S gas was bubbled through the deaerated 3 brine until a level of 500 ppm was reached, as determined by reaction with iodine and titration with sodium thiosulfate. Test coupons were 5-mil thick mild steel shimstock and were sandblasted in a ball mill and tared prior to use. The test coupon, test fluids, and inhibitor were placed in a 7-oz. juice bottle taking care to avoid , oxygen contamination. The bottles were capped and placed on a rotating wheel mounted in a 90C oven. Following the test, the coupons were removed from the bottles, rinsed with soap and water, dipped in 10% hydrochloric acid, and rinsed with water. A plastic wool pad was used to scrub any remaining corrosion products from the coupon, after which the coupon was rinsed, dried, and weighed to deter-- mined the weiqht loss. The percent inhibition provided by ! the inhibitor was calculated with reference to the weight loss of an uninhibited coupon, according to the formula:
, .
(Uninhibited wei~ht loss -. . . Inhibited weight loss) % Inhlblt1On = uninhibited wei~ht los9 .

~ - .
~ 327446 For continuous tests, the inhibitor was added at a level of either 20, 50, or 100 ppm, and the bottle placed on the wheel for 24 hours.
For film persisten~e tests, the coatin~ step 0-5 consisted of addin~ the inhibitor at a level between 500 and 25,000 ppm and placin~ the bottle on the wheel for 1 hour. ~ rinsin~ step followed consisting of removing the coupon from the bottle used for the filmin~ step, replacing it in a second bottle containing fresh fluids, and placing this bottle on the wheel for 1 hour. Finally, a testin~ step was carried out, in which the coupon was placed in a third bottle containing fresh fluids and placed on the wheel for 24 hours.
Table IV below summarizes the corrosion inhibitor test results obtained using this procedure for formulations of the poly(C20-C24)alkylenepolyamines prepared as described in Examples 6 and 9 above.
TABLE IV
;~0 Percent Inhibition Percent Inhibition Wheel Test Polyalkylenepolyamine Polyalkylenepolyamine Conditionsfrom Example 6from Example 9 C2 Continuous 20 ppm 96 99 -~ 25 50 ppm 98 99 100 ppm 96 100 s H2S Continuous -^
20 ppm 94 94 50 ppm 98 98 100 ppm 96 97 C2 Film Persistence - 5,000 ppm 96 99 10,000 ppm 97 98 H2S Film Persistence 5,000 ppm 97 98 , .

/

-01 Example 25 Following the test procedure of Example 24, a sample of polyalkylenepolyamine prepared as described in Example 21 was formulated as described in Example 23 05 (Formulation B) and evaluated in a CO2 film persistence wheel test at 2,000 ppm treatment level and 190F side-by-side with Nalco Visco 945, a commercial corrosion inhibitor formulation available from Nalco Chemical Company. ~fter 24 hours, the polyalkylenepolyamine formulation of the present invention had provided 96%
corrosion protection, whereas the commercial Nalco Vi~sco 945 inhihitor provided only 82% corrosion protection.
Example 26 ' Comparison of Corrosion Inhibitor Performance of Formulated Po1y(C20-C24)alkylenepolyamines and Other Commercial Corrosion Inhibitors in CO2: Film Persistence Wheel Test Evaluation , In addition to the standard testing conditions described in Example 24, the materials of the present , ~ invention were also tested against several commercial ,A, inhibitor formulations at low film persistence test treat-ment levels. Using the same test procedures as described 1 ;n Example 24, a performance advantage was demonstrated `~ for both the poly(C20-C24)alkylenepolyamines of Examples 2 and ~ and their copolymers with ethylenepolyamines from Example 22. This data is summarized in Table V.
`"!
TABLE V
C2 Film Persistence Wheel Tests Percent Inhibition _ -Treatment Polyamine Polyamine Polyamine Tretolite Nalco Level, ppmExample 2Example 8 Example 22 KP310 4910 -' 351,000 99 99 96 91 83 2,000 97 94 94 94 81 5,000 100 97 92 98 87 ` 40 i , "

Example 27 Comparison of Corrosion Inhibitor Performance of Formulated Poly(C20-C24)alkylenepolyamines and Other Commercial Corrosion Inhibitors in C02: Linear Polarization Test Evaluation Cleaned and de~reased mild steel coupons were immersed in a synthetic seawater solution saturated with C2 gas at 90C and equili~rated for 18 hours. The instantaneous general corrosion rates were electrochemi-cally measured using the standard linear polarizationmethod to give the uninhibited corrosion rates for the test coupons, typically 100 to 150 mpy (mils per year) in this environment. To these solutions were then added sufficient amounts of formulated inhibitor to reach 100 ppm total formulation in the corrosion solution. A
comparison was made with Nalco Visco 4907, a commercial nitrogen-cont-aining corrosion inhibitor formulation, available from Nalco Chemical Company. The commercial Nalco formulation was used as received. The polytC20-C24)-alkylenepolyamine sample of Example 6 was used in a formulation similar to that of Example 23 (Formulation A), except that the level of Igepal C0630 surfactant was 10%.
Followin~ addition of the formulated inhibitors, the corrosion rate, CR, was monitored and the percent inhibition calculated according to the formula:

nhibition Uninhibited CR
Both inhibitor formulations quickly lowered the corrosion rate and provided significant inhibition.
Following 18 hours, the inhibited corrosion rates had stabilized at 7 mpy for the Nalco formulation and at 2.2 mpy for the formulated polyalkylenepolyamine inhibitor.

..

...

Claims (48)

1. A polyalkylenepolyamine composition comprising a mixture of (a) at least one C-alkyl-ethylene diamine, and (b) at least one di-(C-alkyl)-diethylenetriamine or at least one di-(C-alkyl)-piperazine or a mixture thereof;
wherein each C-alkyl group on the ethylene diamine, diethylenetriamine and piperazine independently contains from 10 to 28 carbon atoms.

2. The composition according to Claim 1, wherein the composition contains greater than 1% of component (b), relative to component (a).

3. The composition according to Claim 2, wherein the composition contains greater than 5% of component (b), relative to component (a).

4. The composition according to Claim 1, wherein the ratio of component (b) to component (a) is in the range of about 0.05:1 to about 20:1.

5. The composition according to Claim 1, wherein each C-alkyl group independently contains from 14 to 22 carbon atoms.

6. The composition according to Claim 5, wherein each C-alkyl group independently contains from 18 to 22 carbon atoms.

7. A composition comprising the polyalkylenepoly-amine product obtained by the reaction of a 1,2-dihalo-alkane having from 12 to 30 carbon atoms and ammonia.

8. The composition according to Claim 7, wherein the 1,2-dihaloalkane is 1,2-dichloroalkane.

9 The composition according to Claim 7, wherein the 1,2-dihaloalkane has from 16 to 24 carbon atoms.

10. The composition according to Claim 9, wherein the 1,2-dihaloalkane has from 20 to 24 carbon atoms.

11. The composition according to Claim 7, wherein the molar ratio of ammonia to 1,2-dihaloalkane is about 2:1 to 100:1.

12. The composition according to Claim 7, wherein the reaction is carried out under substantially anhydrous conditions.

13. The composition according to Claim 7, wherein the reaction is carried out in the presence of an inert polar organic solvent.

14. The composition according to Claim 13, wherein the solvent is an alkanol.

15. The composition according to Claim 7, wherein the 1,2-dihaloalkane and ammonia are reacted with about 1-to 50 weight percent of ethylene diamine, a higher polyethylenepolyamine or ethylene dichloride to form the polyalkylenepolyamine product.

16. A composition comprising the polyalkylenepoly-amine product obtained by the reaction of a 1-epoxyalkane having from 12 to 30 carbon atoms and ammonia, in the presence of an amination catalyst and hydrogen.

17. The composition according to Claim 16, wherein the 1-epoxyalkane has from 16 to 24 carbon atoms.

18. The composition according to Claim 17, wherein the 1-epoxyalkane has from 20 to 24 carbon atoms.

19. The composition according to Claim 16, wherein the molar ratio of ammonia to 1-epoxyalkane is about 2:1 to 100:1.

20, The composition according to Claim 16, wherein the amination catalyst is selected from the group consist-ing of cobalt-containing and nickel-containing catalysts.

21. The composition according to Claim 20, wherein the amination catalyst is a supported cobalt catalyst.

22. The composition according to Claim 20, wherein the amination catalyst is a supported nickel-rhenium cata-lyst.

23. The composition according to Claim 16, wherein the 1-epoxyalkane and ammonia are reacted with about 1 to 50 weight percent of ethylene diamine or a higher polyethylenepolyamine to form the polyalkylenepolyamine product.

24. A method of inhibiting corrosion of a corrodible metal material which comprises contacting the metal mate-rial with an effective amount of a corrosion inhibiting polyalkylenepolyamine composition comprising a mixture of (a) at least one C-alkyl-ethylene diamine, and (b) at least one di-(C-alkyl)-diethylenetriamine or at least one di-(C-alkyl)-piperazine or a mixture thereof;
wherein each C-alkyl group on the ethylene diamine, diethylenetriamine and piperazine independently contains from 10 to 28 carbon atoms.

25. The method according to Claim 24, wherein each C-alkyl group independently contains from 14 to 22 carbon atoms.

26. The method according to Claim 25, wherein each C-alkyl group independently contains from 18 to 22 carbon atoms.

27. The method according to Claim 24, wherein the polyalkylenepolyamine composition contains greater than 1%
of component (b), relative to component (a).

28. The method according to Claim 27, wherein the polyalkylenepolyamine composition contains greater than 5%
of component (b), relative to component (a).

29. The method according to Claim 24, wherein the ratio of component (b) to component (a) is in the range of about 0.05:1 to about 20:1.

30. A method of inhibiting corrosion of a corrodible metal material which comprises contacting the metal mate-rial with an effective amount of a corrosion inhibiting composition comprising the polyalkylenepolyamine product obtained by the reaction of a 1,2-dichloroalkane having from 12 to 30 carbon atoms and ammonia.

31. A method of inhibiting corrosion of a corrodible metal material which comprises contacting the metal mate-rial with an effective amount of a corrosion inhibiting composition comprising the polyalkylenepolyamine product obtained by the reaction of a 1-epoxyalkane having 12 to 30 carbon atoms and ammonia, in the presence of an amina-tion catalyst and hydrogen.

32. A method of inhibiting corrosion of a corrodible metal material in or around a well through which a corro-sive fluid is produced, which comprises contacting the metal material with an effective amount of a corrosion inhibiting polyalkylenepolyamine composition comprising a mixture of (a) at least one C-alkyl-ethylene diamine, and (b) at least one di-(C-alkyl)-diethylenetriamine or at least one di-(C-alkyl)-piperazine or a mixture thereof;
wherein each C-alkyl group on the ethylene diamine, diethylenetriamine and piperazine independently contains from 10 to 28 carbon atoms.

33. A method of inhibiting corrosion of a corrodible metal material in or around a well through which a corro-sive fluid is produced, which comprises contacting the metal material with an effective amount of a corrosion inhibiting composition comprising the polyalkylenepoly-amine product obtained by the reaction of a 1,2-dichloro-alkane having from 12 to 30 carbon atoms and ammonia.

34. A method of inhibiting corrosion of a corrodible metal material in or around a well through which a corro-sive fluid is produced, which comprises contacting the metal material with an effective amount of a corrosion inhibiting composition comprising the polyalkylenepoly-amine product obtained by the reaction of a 1-epoxyalkane having 12 to 30 carbon atoms and ammonia, in the presence of an amination catalyst and hydrogen.

35. A corrosion inhibiting composition comprising the polyalkylenepolyamine composition of Claim 1 and one or more dimer/trimer acids.

36. The corrosion inhibiting composition according to Claim 35, further comprising one or more ionic or nonionic surfactants and a hydrocarbon solvent.

37. The corrosion inhibiting composition according to Claim 36, further comprising one or more alcohols.

38. A corrosion inhibiting composition comprising the composition of Claim 7 and one or more dimer/trimer acids.

39. The corrosion inhibiting composition according to Claim 38, further comprising one or more ionic or non-ionic surfactants and a hydrocarbon solvent.

40. The corrosion inhibiting composition according to Claim 29, further comprising one or more alcohols.

41. A corrosion inhibiting composition comprising the composition of Claim 16 and one or more dimer/trimer acids.

42. The corrosion inhibiting composition according to Claim 41, further comprising one or more ionic or non-ionic surfactants and a hydrocarbon solvent.

43. The corrosion inhibiting composition according to Claim 42, further comprising one or more alcohols.

44. A composition comprising (a) about 15 to 30% of a polyalkylenepolyamine corrosion inhibitor composition comprising a mixture of (i) at least one C-alkyl-ethylene diamine, and (ii) at least one di-(C-alkyl)-diethylenetriamine or at least one di-(C-alkyl)-piperazine or a mixture thereof;
wherein each C-alkyl group on the ethylene diamine, diethylenetriamine and piperazine independently contains from 10 to 28 carbon atoms;
(b) about 15 to 30% of a dimer/trimer acid;
(c) about 1 to 10% of a nonionic surfactant;
(d) about 25 to 75% of a hydrocarbon solvent; and (e) about 0 to 5% of an alcohol.

45. A composition comprising (a) about 15 to 30% of a corrosion inhibitor compo-sition comprising the polyalkylenepolyamine product obtained by the reaction of a 1-epoxyalkane having from 12 to 30 carbon atoms and ammonia, in the presence of an amination catalyst and hydrogen;
(b) about 15 to 30% of a dimer/trimer acid;
(c) about 1 to 10% of a nonionic surfactant;
(d) about 25 to 75% of a hydrocarbon solvent; and (e) about 0 to 5% of an alcohol.

46. A composition comprising (a) about 15 to 30% of a corrosion inhibitor compo-sition comprising the polyalkylenepolyamine product obtained by the reaction of a 1,2-dihaloalkane having from 12 to 30 carbon atoms and ammonia;
(b) about 15 to 30% of a dimer/trimer acid;
(c) about 1 to 10% of a nonionic surfactant;
(d) about 25 to 75% of a hydrocarbon solvent; and (e) about 0 to 5% of an alcohol.

47. A composition comprising (a) about 15 to 30% of a corrosion inhibitor compo-sition comprising the polyalkylenepolyamine product obtained by the reaction of a 1,2-dihaloalkane having from 12 to 30 carbon atoms and ammonia and wherein the 1,2-dihaloalkane and ammonia are reacted with about 1 to 50 weight percent of ethylene diamine, a higher polyethylenepolyamine or ethylene dichloride to form the polyalkylenepolyamine product;
(b) about 15 to 30% of a dimer/trimer acid;
(c) about 1 to 10% of a nonionic surfactant;
(d) about 25 to 75% of a hydrocarbon solvent; and (e) about 0 to 5% of an alcohol.

48. A composition comprising (a) about 15 to 30% of a corrosion inhibitor composition comprising the polyalkylenepolyamine product obtained by the reaction of a 1-epoxyalkane having from-12 to 30 carbon atoms and ammonia, in the presence of an amination catalyst and hydrogen, and wherein the l-epoxyalkane and ammonia are reacted with about 1 to 50 weight percent of ethylene diamine or a higher polyethylenepolyamine to form the polyalkylenepolyamine product;
(b) about 15 to 30% of a dimer/trimer acid;
(c) about 1 to 10% of a nonionic surfactant;
(d) about 25 to 75% of a hydrocarbon solvent; and (e) about 0 to 5% of an alcohol.