FR2614630A1 - PROCESS FOR INHIBITING CORROSION, AND COMPOSITIONS USEFUL IN THIS PROCESS - Google Patents

Abstract

THE INVENTION RELATES TO A PROCESS FOR INHIBITING CORROSION OF COPPER OR ALLOY CONTAINING COPPER. THE SURFACE OF THE COPPER, OR OF THE COPPER CONTAINING ALLOY, IS PLACED IN CONTACT WITH A MIXTURE OF A COMPOUND RESPONDING TO FORMULA A: (CF DRAWING IN BOPI) IN WHICH R IS A RADICAL ALKYL, CYCLOALKYL, ARALKYL OR ARYL , A HETEROCYCLIC RADICAL OR A RADICAL - (CH) -CHO (N DESIGNATED A NUMBER FROM 1 TO 6), AND A COMPOUND RESPONDING TO FORMULA B: R-NH (B) IN WHICH R REPRESENTS A RADICAL ALKYL, CYCLOALKYL , ARALKYL OR ARYL, A HETEROCYCLIC RADICAL OR A RADICAL - (CH) -NH (M DESIGNATES A NUMBER FROM 1 TO 6). POSSIBLE AREAS OF APPLICATION: LUBRICANTS, HYDRAULIC FLUIDS, FLUIDS FOR METAL WORKING, HEAT FLUIDS, TRANSFORMER AND SWITCH OILS.

Description

The present invention relates to a method for inhibiting corrosion of the

  copper and copper alloys. It also relates to compositions which, in contact with copper or copper alloys, have the function of inhibiting corrosion, as well as the application of a combination of certain aldehydes and certain amines as a corrosion inhibitor

  for copper and copper alloys.

  It is well known that copper surfaces may be corroded when in contact with certain aqueous or non-aqueous media. In addition

  products resulting from the corrosion of copper

  lyses the decomposition of organic media that are in contact with the corrosion-sensitive surface, and can electrolytically trigger corrosion of other metals that may be present,

  for example iron or aluminum.

  Many compounds with extremely varied structures have been proposed as inhibitors of copper corrosion in media such as

  systems or functional fluids.

  Among many others, compounds of a group comprising Schiff's bases derived from the condensation of aromatic amines and aromatic aldehydes have been found very effective. In "Surface

  Coatings and Technology ", 27, 175-86 (1986) the N- (mercap-

  to-2 phenyl) -salicylidene imine is described as being

  corrosion inhibitor for copper in aqueous alcoholic media, while in "Surface Coatings and Technology", 29, 141-151 (1986), the same molecule and its analogs are presented as corrosion inhibitors for copper and its alloys in acidic medium. Previous publications describe Schiff bases as metal corrosion inhibitors in a number of systems. Thus, N, N'-bis (2-hydroxybenzylidene) ethylene diamine and N, N'-bis (4-methoxybenzylidene) ethylene diamine are shown in J. Electrochem. India, 32, 397-401 (1983), as corrosion inhibitors for zinc in sulfamic acid; U.S. Patent 3,865,739

  discloses an inhibitor which is an alkylidene-imino

  thiadiazole; GB 1 434 354 describes azomethine prepared by condensation of cinnamaldehyde with 4-amino hexane-nitrile as an inhibitor for steel

in hydrochloric acid.

  GB 803 541 relates to a mixture of aldehydes and amines in acidic liquids, in particular for stripping, a mixture which is used

  to protect metal surfaces.The metals mentioned

  in this document are iron and steel and,

  according to the invention, aluminum and zinc.

  In "Werkstoffe und Korrosion", 23rd year, Issue 6, 1972, Mr. N. Desai cites, on pages 483 to 487, various compounds as corrosion inhibitors for copper. There is mention of aldehydes and

  amines but these compounds are always used separately.

  rately. In contrast to the above-mentioned state of the art, in which it is proposed, for example, to inhibit the corrosion of metals by means of Schiff bases, the present inventor has found that mixtures of Schiff base precursors exert a remarkable inhibitory effect on the corrosion of copper in different media, for example in functional fluids and

in aqueous systems.

  The subject of the present invention is therefore a process for inhibiting the corrosion of copper or a metal containing copper, characterized in that the surface of the copper or the surface of a copper alloy is brought into contact with a quantity effective, with respect to the anti-corrosion action, of a mixture consisting of: a compound of formula (A):

R -C = O (A)

  Wherein R 1 is C -C 9 alkyl

1 1_ 19

  linear or branched chain, C5-C12 cycloalkyl, C7-C13 aralkyl, C6, C14 or C14 aryl, C14-C14 aryl;

  substituted C6, C10 or C14 aryl, a hetero radical

  monocyclic rocyclic ring containing at most 5 carbon atoms in its ring, or a radical of formula (I): - (CH 2) n -CHO (I) in which n denotes a number from 1 to 6, and a compound corresponding to formula (B):

R2-NH2 (B)

  in which R2 represents a linear or branched C 1 -C 19 alkyl, a C 5 -C 12 cycloalkyl, a C 7 -C 13 aralkyl, a C 6, C 10 or C 14 aryl, a C 6 -C 10 aryl or

  Substituted C14, a heterocyclic radical

  clique containing at most 5 carbon atoms in its ring, or a radical of formula (11):

26 1 4630

- (CH2) mNH2 (II)

  in which m denotes a number from 1 to 6.

  The C1-C19 alkyl which R1 or R2 may represent is linear or branched and may be, for example, a methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, n-pentyl or n-hexyl radical. , n-heptyl, noctyl, 2-ethylhexyl, n-nonyl, n-decyl, n-dodecyl,

  n-tridecyl, n-pentadecyl, n-heptadecyl or n-nonadecyl.

  As C 5 -C 12 cycloalkyl, R 1 or R 2 is, for example, a cyclopentyl or cyclohexyl radical,

  cyclooctyl, cyclodecyl, adamantyl or cyclododecyl.

  As a C 7 -C 13 aralkyl, R 1 or R 2 may be benzyl, 2-phenylethyl, benzhydryl

or naphthylmethyl.

  As the C 6, C 10 or C 14 aryl, R 1 or R 2 is phenyl, naphthyl or anthracenyl. The substituents which may be on these aryl radicals will be taken for example from the group consisting of the hydroxyl, amino, mercapto, carbonyl, carboxy and sulpho radicals and by the radicals CR in which o

  R3 represents hydrogen or hydroxy.

  As a heterocyclic radical, R or R2 is for example a pyridyl, furyl or thienyl radical. The compounds of formula (A) which are more particularly preferred are those of formula (A 1): ## STR2 ## In which X represents hydrogen, a hydroxy, a mercapto or a radical CR whose symbol R3 denotes II 3

hydrogen or a hydroxy radical.

  Other preferred compounds (A) are those which have the formula (A 2): OHC (CH 2) nCHO (A 2)

  in which n is a number from 1 to 6.

  The compounds of

  formula B which respond more particularly to the

mule (B 1): \. / Y i he (B 1),

</ \ E2

  in which Y represents hydrogen or a radical

  amino, hydroxy, mercapto, carboxy or sulfo.

  Examples of compounds of formula A which may be present in the mixture are: acetaldehyde, propionaldehyde, butyraldehyde, isobutyraldehyde, 2-ethylbutanal, valeraldehyde, isovaleraldehyde and hexanal , heptanal, octanal, nonanal, decanal, undecanal, dodecanal,

  tetradecanal, pentadecanal, hexadecanal, octadecan

  decanal, eicosanal, cyclopentane-carbaldehyde, cyclohexanecarbaldehyde, cyclooctane-carbaldehyde, cyclododecane-carbaldehyde, phenylacetaldehyde, 3-phenylpropionaldehyde, benzhydrylcarbaldehyde,

  naphthylacetaldehyde, benzaldehyde, salicylate

  hyde, 3-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 2-mercaptobenzaldehyde, 3-mercaptobenzaldehyde,

  4-mercaptobenzaldehyde, phthalaldehyde, isophthalate

  laldehyde, terephthalaldehyde, 2-carboxydobenzene

  hyde, 4-carboxybenzaldehyde, 2-sulfobenzaldehyde,

  4-sulfobenzaldehyde, naphthaldehyde-1, naphthalene

  dehydro-2, 2-hydroxy-naphthaldehyde-I, 2-mercapto

  naphthaldehyde-1, anthracene-carbaldehyde-1, anthrax-

  co-carbaldehyde-2, 2-hydroxy-anthracene-carbaldehyde-1, malonaldehyde, succinaldehyde, glutaraldehyde,

  adipaldehyde, heptane-dicarbaldehyde-1, 5, hexane,

  dicarbaldehyde-1,6, furfural and thiophene-carbal-

  dehyde-2. As compounds of formula B, mention will be made of

for example:

  methylamine, ethylamine, propylamine, isopropylamine,

  pylamine, n-butylamine, sec-butylamine, tert-butylamine,

  butylamine, n-pentylamine, tert-pentylamine, n-hexylamine, nheptylamine, n-octylamine, ethyl-2

  hexylamine, n-nonylamine, n-decylamine, n-

  cylamine, n-dodecylamine, n-tridecylamine, n-

  tetradecylamine, hexadecylamine, octadecylamine, cyclopentylamine, cyclohexylamine, cycloheptylamine,

  cyclo-octylamine, adamantamine-1, cyclododecyl-

  amine, benzylamine, (2-phenylethyl) -amine, benzhydrylamine, (3-phenylpropyl) -amine, (phenyl-4)

  butyl) -amine, naphthyl-methylamine, aniline, hydro-

  xy-2 aniline, 3-hydroxy aniline, 4-hydroxy aniline,

  2-mercaptoaniline, 3-mercaptoaniline,

  to-4 aniline, 2-amino benzaldehyde, o-amino acid,

  benzoic acid, 3-amino-benzoic acid, 4-amino acid

  benzoic acid, sulfanilic acid, 2-amino-benzene

  sulfonic acid, dimethylamine, diamino-1,2-ethane, 1,3-diamino propane, 1,4-diamino-butane, 1,5-diamino pentane, 1,6-diamino-hexane, 1-phenylene diamine, m-phenylenediamine, p-phenylenediamine, 1-amino-naphthalene, 1-amino-2-naphthol, 1-amino-7-naphthol, 3-amino-2-naphthol 4-amino-1-naphthol, 8-amino-2-naphthol,

2614630.

  3-amino-2-naphthoic acid, 2-amino-naphthalene acid

  sulfonic acid-1, 4-amino-naphthalene-1-sulfonic acid, 5-amino-2-naphthalenesulfonic acid, 8-amino acid

  naphthalene-2-sulfonic acid, 3-amino-naphthalene-disul-

  2.7-fox, 7-amino-naphthalene-1,3-disulfonic acid, 1-amino-anthracene, 2-amino-anthracene, 2-amino

pyridine and 3-amino pyridine.

  Treatment of metal surfaces

  can be executed in different ways.

  For example, the copper surface may be wrapped in a film or coating impregnated with sufficient quantities of the compounds of formulas (A) and (B); or the copper surface can be dipped into a solution, for example into an aqueous solution, which contains sufficient amounts of the compounds of formulas (A) and (B). Normally the metal surface is in constant contact with a substrate causing corrosion of the metal surface. In such cases

  metal surfaces containing copper may be

  effectively treated against corrosion by addition of an effective amount, with regard to the anti-corrosion effect, of a mixture of the compounds of formulas (A) and (B). In all the methods which have just been indicated, the mixture may contain non-equimolar amounts of (A) and (B), for example

  in a ratio between 3: 1 and 1: 3, but

has an equimolar mixture.

  The subject of the present invention is therefore also a composition which contains a substrate in contact with copper or with a metal containing copper, and an amount which is effective, as far as

  the anti-corrosion effect, advantageously a quantity

  between 0.001 and 5% by weight, preferably between 0.01 and 1% by weight, relative to the total weight of the substrate, of a mixture of the compounds of formulas (A)

and (B) as defined above.

  Substrates which can be treated in accordance with the present invention include functional liquids, such as lubricants, for example lubricants containing a mineral oil, a poly-olefin or a synthetic base consisting of

  carboxylic acid esters; hydration liquids

  for example based on mineral oils, phosphoric esters, aqueous mixtures of polyglycols and polyglycol ethers, or systems containing glycols; LH (oil-in-water) or HL (water-in-oil) emulsions, liquids for machining metals based on mineral oils or aqueous systems; cooling media for water-based machines or an aqueous glycol or a mixture of ethylene glycol or propylene glycol and methanol; transformer or switch oils; as well as aqueous systems, eg industrial cooling water, aqueous air conditioning systems, steam generator systems,

  systems for evaporation of seawater; warming

  hydrostatic fans; and aqueous heating systems

  or closed circuit cooling.

  When the functional fluids are synthetic lubricants they are, for example, lubricants based on a diester derived from a diacid and a monoalcohol, such as dioctyl sebacate or dinonyl adipate; based on a triester derived from trimethylolpropane and a monoacid or a mixture of such acids, such as trimethylolpropane tripelargonate, tri-octanoate (tricaprylate) trimethylolpropane or a mixture thereof ; based on a tetraester derived from pentaerythrol and a monoacid or a mixture of monoacids, such as pentaerythrol tetraoctanoate, or based on complex esters prepared from monoacids, diacids and monoalcohols, such as complex esters prepared from trimethylolpropane, octanoic acid ("caprylic") and sebacic acid, or mixtures thereof.

of these.

  In the state of the art, there are other synthetic lubricants, especially those described in "Schmiermittel-Taschenbuch", ed. H thig, Heidelberg, 1974 in "Ullmann's Enzyklopadie der technischen Chemie", volume 13, pages 85-94 (Verlag Chemie, Weinheim 1977), or in D. Klamann, "Schmierstoffe und verwandte

  Produkte ", pages 158-174 (Verlag Chemie, Weinheim 1982).

  In addition to the preferred mineral oils, phosphates are particularly suitable, for example

  polyglycols, polyalkylene glycols and poly-α-

  olefins. For its different properties

  to improve a functional liquid

  form of the present invention may also contain other additives, including, for oil-based systems, one or more of the antioxidants, metal deactivators, other corrosion inhibitors or rust, improvers viscosity indexes, freezing point depressants, dispersants, surfactants, high pressure additives and friction reducing agents, and, for water-based systems, one or more additives selected from antioxidants, other corrosion and rust inhibitors, metal deactivators, high additives

  pressure and friction reducers ("anti-wear"),

  plexants, precipitation inhibitors, biocides,

buffers and antifoams.

  Examples of additional additives for use in oil-based systems are given below.

  EXAMPLES OF PHENOLIC ANTIOXIDANTS

  1. 2,6-Tert-butyl-2,6-methylphenol, 2,6-ditert-butyl-phenol, 2,6-tert-butyl-2,6-phenol, ditert-butyl-2,6-ethyl-4-phenol, ditert-butyl-2,6-phenol 2,6-butyl-n-butyl-4-phenol, 2,6-ditert-butyl-4-isobutylphenol, 2,6-dicyclopentyl-4-methylphenol, (2-methylcyclohexyl) -2,4-dimethylphenol, dioctadecyl -2,6-methyl-phenol, 2,4,6-tricyclohexyl phenol, 2,6-ditert-butyl-4-methoxymethyl phenol and o-tert-butyl-phenol. 2. 2,6-Tert-butyl-4-methoxy-phenol, 2,6-ditert-butyl-hydroquinone, ditert-pentyl-2,5-hydroquinone and

  2,6-diphenyl-4-octadecyloxyphenol.

  3. Thio-2,2 'bis- (tert-butyl-6-methyl-4-phenol), thio-2,2' bis- (octyl-4-phenol), thio-4,4 'bis- (2,2-bis) benzyl bis (diphenyl sulphides) tert-butyl-6-methyl-3-phenol) and

  thio-4,4'bis- (tert-butyl-6-methyl-2-phenol).

  4. Alkylidene-bis-phenols methylene-2,2'bis- (tert-butyl-6-methyl-4-phenol), methylene-2,2'bis- (tert-butyl-6-ethyl-4-phenol), methylene-2 2 'bis- / methyl-4-methylcyclohexyl) -6-phenol, methylene-2,2'-bis (4-methyl-6-cyclohexylphenol), methylene-2,2' bis- (nonyl-6-methyl-4-phenol) ), 2,2'-methylenbis (4,6-ditert-butyl) phenol, 2,2'-ethylidene bis (4,6-diterto) -phenol), 2,2'-ethylidene bis (tert-butyl) 6-isobutyl-4 or -5 phenol), methylene-2,2'bis [(d-methylbenzyl) -6-nonyl-4-phenol], methylene-2,2'bis- (c, d-dimethylbenzyl) - 4-nonyl-4-phenol, 4,4-methylene-bis (2,6-tert.-butyl) phenol, methylene-4,4'-bis (tert-butyl-6-methyl-2-phenol), bis (tert-butyl) 4-hydroxy-2-methyl-phenyl) -1,1-butane, bis (3-tert-butyl-5-methyl-2-hydroxy-benzyl) -4-methyl-4-phenol, tris (4-tertbutyl-4-hydroxy-methyl) 2 phenyl) -1,3,3-n-dodecylthio-3-butane, bis- [bis (tert-butyl-3-hydroxy-4-phenyl) -3,3-butyrate] ethylene glycol,

  bis- (tert-butyl-3-hydroxy-4-methyl-5-phenyl) -dicyclo

  pentadiene and bis-Z terephthalate (tert-butyl-3-hydroxy-2-methyl-5-methyl)

  benzyl) -2-tert-butyl-6-methyl-4-phenyl.

5. Benzylic compounds

  tris- (3,5-ditert-butyl-4-hydroxy-benzyl) -l, 3,5 tri-

  2,4,6-methyl-benzene, bis (3,5-ditert-butyl-4-hydroxy-benzyl) sulfide,

  (3,5-ditert-butyl-4-hydroxy-4-benzylthio) isoacetate

  octyl, bis (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) dithioterephthalate, tris (3,5-ditert-butyl-4-hydroxy-4-benzyl) isocyanurate, tris (tert-butyl) isocyanurate 4-hydroxy-2,6-dimethylbenzyl), dioctadecyl (3,5-ditert-butyl-4-hydroxybenzyl) phosphonate and

  calcium salt mono-ethyl ester of the acid (ditert-

  butyl-3,5-hydroxy-4-benzyl) -phosphonic acid.

  6. 4-Lauroylmino phenol-4-amylamino phenol, 4-stearoylamino-phenol, 2,4-bisoctylthio (3,5-ditert-butyl-4-hydroxy-anilino) -6-triazine-1,3,5 and

  N- (octyl butert-butyl-3,5-hydroxy-4-phenyl) -carbamate.

  7. esters of 3- (3,4-tert-butyl-4-hydroxyphenyl) propionic acid which are derived from monoalcohols or polyols, these alcohols being for example: methanol, diethylene glycol, octa decanol, triethylene glycol, hexane-1,6-diol, pentaerythrol, neopentyl glycol, tris (hydroxyethyl) isocyanurate,

  thio-diethylene-glyco] and N, N'-bis (hydroxyethyl) -

  oxamide. 8. Esters of 5-tert-butyl-4-hydroxy-3-methylphenylpropionic acid which are derived from monoalcohols or polyols, these alcohols being for example: methanol, diethylene glycol, octadecanol triethylene glycol, hexane-1,6-diol, pentaerythrol, neopentyl glycol, tris (hydroxyethyl) isocyanurate,

  thio-diethylene glycol and N, N'-bis- (hydroxyethyl) -

  oxamide. 9. Amides of the acid (ditert-butyl-3,5-hydroxy-4-phenylpropionic acid, for example:

  N, N'-bis (3,5-tert-butyl-4-hydroxyphenylpropionyl) -

hexamethylenediamine,

  N, N'-bis (3,5-tert-butyl-4-hydroxyphenylpropionyl) -

trimethylenediamine and

  N, N'-bis (3,5-tert-butyl-4-hydroxyphenylpropionyl) -

hydrazine.

EXAMPLES OF AMINE ANTIOXIDANTS

  N, N'-diisopropyl-p-phenylenediamine, N, N'-di-sec-butyl-p-phenylenediamine, N, N'-bis (1,4-dimethylpentyl) -p-phenylenediamine, N, N'-bis (1-ethyl-3-methyl-pentyl) -p-phenylenediamine, N, N'-bis- (methyl-1-heptyl) p-phenylenediamine, N, N'-dicyclohexyl-p- phenylenediamine, N, N'-diphenylp-phenylenediamine, N, N'-bis (2-naphthyl) -p-phenylenediamine, Nisopropyl-N'-phenyl-p-phenylenediamine, N- ( 1,3-dimethylbutyl) -N'-phenylp-phenylenediamine, N- (methyl-1-heptyl) -N'-phenyl-p-phenylenediamine, Ncyclohexyl-N'-phenyl-p-phenylenediamine, (4-p-toluenesulfonylamino) -4-diphenylamine, N, N'-dimethyl-N, N'-di-sec-butyl-p-phenylenediamine, diphenylamine, N-allyl-diphenylamine, 4-isopropoxy-diphenylamine, phenylamino- 1 naphthalene, 2-phenylamino-naphthalene,

  octylated diphenylamines, for example p, p'-di-tert-octyl-

  diphenylamine, 4-n-butylamino phenol, 4-butyrylamino phenol, 4-nonanoylamino phenol, 4-dodecanoylamino phenol, octadecanoylamino-4-phenol, bis (4-methoxyphenyl) -amine, ditert-butyl-2,6-dimethylaminomethyl-4 phenol, 2,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis (dimethylamino) -4,4'-diphenylmethane, bis (2-methylphenyl) -amino] -1,2 ethane, bis ( phenylamino) -1,2 propane, (o-tolyl) biguanide, bis [4- (dimethyl-1,3-butyl) phenyl] amine, phenylamino-1 naphthalene tert-octyl, mixture of tert-butyl and tert-octyldiphenylamines monoalkyl and dialkyl, 2,3-dihydro-3,3-dimethyl-4-benzothiazine-1,4, phenothiazine and N-allyl-phenothiazine.

EXAMPLES OF OTHER ANTIOXIDANTS

  aliphatic or aromatic phosphites, esters of thiodipropionic acid or thio-diacetic acid,

  and salts of dithiocarbamic acid or dithiocarbamic acid

  phosphoric. EXAMPLES OF METAL DEACTIVANTS, for example for copper: triazoles, benzotriazoles and their derivatives, tolutriazoles and their derivatives, 2-mercaptobenzothiazole, 2-mercaptobenzotriazole, 2,5-dimercapto benzotriazole, 2,5-dimercapto

  benzothiadiazole, methylene-5,5 'bis-benzotriazole, tetra-

  hydro-4,5,6,7 benzotriazole, salicylidene-propylene-dia-

  mine, salicylamino-guanidine and its salts.

EXAMPLES OF RUST INHIBITORS

  a) Organic acids, their esters, metal salts and anhydrides, for example:

  N-oleoylsarcosine, sorbitan mono-oleate, naphtha-

  lead compounds, alkenylsuccinic anhydrides, such as dodecenylsuccinic anhydride, partial esters and partial amides of alkenylsuccinic acids, and

(4-nonylphenoxy) -acetic acid.

  (b) Nitrogen compounds, for example: I. primary or secondary aliphatic or cycloaliphatic amines and salts of amines of organic or inorganic acids, for example carboxylates

of oil-soluble alkylammoniums.

  II. heterocyclic compounds, for example imidazolines

and substituted oxazolines.

  c) Phosphorus compounds, for example: salts formed by amines and partial esters of phosphoric acid or partial esters of phosphonic acids, and dithiophosphates of dialkyl and zinc. (d) Sulphide compounds, for example: dinonyl-naphthalene-barium sulphonates and salts

  calcium from petroleum sulfonation products.

  EXAMPLES OF VISCOSITY INDEX IMPROVERS

  Polyacrylates, polymethacrylates, vinylpyrrolidone copolymers

  lidone / methacrylate, poly (vinylpyrrolidones), polybu-

  polymers, olefin copolymers, styrene / acryl copolymers

lates and polyethers.

  EXAMPLES OF FREEZING POINT SLICERS

  Polymethacrylates and alkylated derivatives of naphthalene.

EXAMPLES OF DISPERSANTS / SURFACTANTS

  Polybutenyl succinamides or succinimides derived from polybutenyl phosphonic acids and basic

of barium.

EXAMPLES OF ANTI-WEAR ADDITIVES

  Compounds containing sulfur and / or phosphorus and / or halogen, such as sulphurated vegetable oils,

  dithiophosphates of dialkyl and zinc, phos-

  tritolyl phage, chlorinated paraffins, di- and

  tri-sulfides of alkyls and aryls, phosphorothio-

  triphenyls, diethanolaminomethyltolyltria-

  zole and bis (2-ethylhexyl) aminomethyltolyltriazole.

  When dealing with fully aqueous substrates, such as in water-cooled systems, air-conditioning systems, steam systems, systems for the evaporation of water from sea, hydro-electric heaters

  static and heating and cooling systems

  with a closed circuit, inhibitors -

  additional corrosion, especially water-soluble zinc salts, phosphates, polyphosphates, phosphonic acids and their salts, such as

  hydroxy-ethylidene diphosphonic acid, nitrilo-tris

  (methylenephosphonic acid) and methylamino-dimethyl

  ethylene phosphonocarboxylic acid and their salts, for example the compounds which are described in DE A 2,632,774, hydroxyphosphonoacetic acid, 2-phosphono butane-tricarboxylic acid, 1,2,4 and those GB 1 572 406 discloses nitrates, such as sodium nitrate, nitrites, such as sodium nitrite, molybdates, such as sodium molybdate, tungstates, silicates, such as

  sodium silicate, benzotriazole, bis-benzotria-

  zole or derivatives of benzotriazole or tolutriazole which deactivate copper, or Mannich bases which

  derive therefrom, N-acyl sarcosines, N-acyl

  imino-diacetics, ethanolamines, fatty amines

  and poly (carboxylic acids), such as poly-

  (maleic acid) and poly (acrylic acid), as well as the corresponding alkali metal salts,

  copolymers of maleic anhydride, such as copolymers

  lymers of maleic anhydride and sulfonated styrene, copolymers of acrylic acid, such as copolymers of acrylic acid and hydroxyalkylated acrylic acids, and substituted derivatives of poly (acids)

  maleic) and poly- (acrylic acids) and their

  lymers, as well as the corresponding alkali metal salts.

  In fully aqueous systems it is furthermore possible to use, in accordance with the present invention, a copper corrosion inhibitor derived from

  triazole and dispersants and / or surfactants

  such as polymerized acrylic acids (or their salts), phosphino-polycarboxylic acids (such as those described and claimed in GB 1 458 235), the cotelomeric compounds described in EP A 0 150 706, hydrolyzed polyacrylonitrile, polymerized methacrylic acid and its salts, polyacrylamide and copolymers

  of it with acrylic acid and methacrylate

  ligninsulfonic acids and their salts,

  tannin, condensation products of a naphtha

  talenesulfonic acid with formaldehyde, starch and its

  derivatives, cellulose, -copolymers of acrylic acid,

  Examples of such compounds are styrene / maleic anhydride copolymers and sulfonated homopolymers of styrene, such as those described in US Pat. No. 4,029,577. 4,374,733, and combinations thereof, special surfactants, such as 2-phosphono-butane-1, 2,4-tricarboxylic acid, acetodiphosphonic acid, hydrolysed poly (maleic anhydride) and its salts , alkanephosphonic acids, hydroxyphosphonoacetic acid, amino-1-amino acids,

  alkane-diphosphonic acid-1, let their salts, and poly-

alkali metal phosphates.

  In addition, precipitation agents such as alkali orthophosphates or carbonates can be used; oxygen sensors, such as alkali metal sulfites and hydrazines; sequestrants, such as nitrilo-triacetic acid and its salts; defoamers, such as silicones, by

  poly- (dimethylsiloxanes), distearyl-sebacetate

  was obtained from ethylene oxide and / or

2 6 1 4 6 3 C

  propylene oxide, with, in addition, fatty alcohols, such as caprylic alcohol and its condensation products with ethylene oxide; and biocides,

  including amines, quaternary ammonium compounds, chlorophenols, sulfur compounds, such as sulfones,

  methylene-bis-thiocyanates and carbamates, isothiazolones, brominated propionamides, triazines, phosphonium compounds, chlorine and chlorine-releasing compounds, as well as organometallic compounds, such as tributyltin oxide. The compounds of formulas A and B have both excellent deactivation properties for copper and good solubility in substrates

  aqueous or oil-based substrates.

  The following examples illustrate the present invention. In these examples parts and percentages are by weight unless otherwise indicated.

EXAMPLES 1 to 11

  A 0.05% solution of an equimolar mixture of a compound of formula A with a

  compound of formula B in a mixture of water and ethylene

  75:25 ratio glycol whose water contains, per liter, 0.132 g of MgSO4. 7H20 and 0.68 g of CaCl 26H20 (water 0.132 g of gSO4VH20 t 0.6 g of aC.H20 (water according to the test of DIN 51 360).

  The solution is adjusted to 8.5 with NaOH.

  A copper foil (20 x 50 x 0.1 mm) is polished by rubbing it with an impregnated cotton ball

  water and pumice spray, dry and weigh.

  It is then completely immersed in 50 ml of the solution described above in a 60 ml flask equipped with a screw closure. The bottle is kept for 24 hours in an oven at 70 ° C. At the end of this time the sheet is extracted, washed and dried, and its color is determined (using the color scale of the standard ASTM D 130). The foil is then immersed for 15 seconds in 5N hydrochloric acid at 20 ° C, washed, dried and weighed again. The results obtained are gathered

in table 1.

  EXAMPLE Compound of Inhibit Compound Results of Formula A Formula B R 1 R 2 Appearance of Metal and Eval according to

ASTM D 130

TEMOINIO 4D

  ## STR2 ## The green film was obtained 2 2 -OH CfH4 2-HS-C6H & 67.57 thick brown film 3 "2-NH2-C6H4 83.9 1B 4" 2-CO2H. C6H4 71.0 lB C6H5 2-HO.Cl6H4 6914 lA / lB 6 "2-HS.C6H4 95.2 lA / lB

7 "2-NH2.C6HI 64.5 2C

  8 "2-CO2H.C6H 100 lA 9 (CH2) 3CHO 2-CO2H-C6H4 95.2 thick brown film

"4-CO2H-C6H4 82.2 3A

  11 4-SO3H-C6Hk 71.0 black areas and orange areas

26 1 4630

  The assessment is performed at levels 1 to 4 and, at each of these levels, according to a fine subdivision using the designations A to D. The signs used have the meanings given in the following extract from ASTM D 130:

  1 slightly matt A light orange, practically

  identical to that of the freshly polished test tube B dark orange 2 moderately matt C multicolored with lavender blue or silver 3 matt dark Covered with magenta 4D corrosion

Claims (14)

  1. Process for inhibiting corrosion of the   copper or a metal containing copper, a process   terized in that one puts the surface of the copper, or of   the alloy containing copper, in contact with a quantity   an effective mixture for the inhibition of corrosion of a mixture of: a compound of formula (A): R -C = O (A)   1! Wherein R 1 represents linear or branched C 1 -C 19 alkyl, C 5 -C 12 cycloalkyl, C 7 -C 13 aralkyl, C 6, C 10 or C 14 aryl,   substituted C6, C10 or C14 aryl, a hetero radical   monocyclic ring containing at most 5 carbon atoms in its ring, or a radical of formula (I): - (CH2) n-CHO (1) in which n denotes a number from 1 to 6, and a compound corresponding to formula (B): R2-NH2 (B)   in which R2 represents a linear or branched C 1 -C 19 alkyl, a C 5 -C 12 cycloalkyl, a C 7 -C 13 aralkyl, a C 6, C 10 or C 14 aryl, a C 6 -C 10 aryl or   Substituted C14, a heterocyclic radical   clique containing at most 5 carbon atoms in its ring, or a radical of formula (II): - (CH2) m -NH2 (I) 26 1 4630   in which m denotes a number from 1 to 6.   2. Method according to claim 1   characterized in that the compound of formula (A) is a compound   compound which has the formula (A 1): embedded image in which X represents hydrogen, a hydroxy, a mercapto or a radical -CR3 whose R3 symbol denotes hydrogen or hydroxy.   3. Process according to claim 1, characterized in that the compound of formula A corresponds more particularly to formula (A 2): OHC (CH2) CHO (A 2)   in which n is a number from 1 to 6.   4. Process according to any one of   Claims 1 to 3, characterized in that the compound   of formula B is a compound of formula (B 1): (B 1) Y-XNH2   in which Y represents hydrogen or a radical   amino, hydroxy, mercapto, carboxy or sulfo.   5. Process according to any one of   Claims 1 to 4, characterized in that the mixture   contains A and B in a molar ratio between 3: 1 and 1: 3. 26 1 463G   6. Process according to any one of   Claims I to 5, characterized in that the mixture   contains equimolar amounts of the compounds A and B. 7. Composition containing a substrate in contact with copper, or with a metal containing copper, and a sufficient amount, as   of the inhibition of corrosion, a mixture of   poses of formulas A and B according to claim 1.   8. A composition according to claim 7 which contains from 0.001 to 5% by weight, based on the total weight of the substrate, of a mixture of the compounds of formulas A and B. 9. Composition according to claim 8 which contains from 0.01 to 1% by weight, relative to the total weight of the substrate, of the mixture of compounds of formulas A and B.   10. Composition according to one of the   8 and 9 which contains equimolar amounts of the compounds of formulas A and B. 11. Composition according to any one   Claims 7 to 10 wherein the substrate is   lubricant, hydraulic fluid, oil   in water or water-in-oil, a liquid for the   metals, machinery coolant, transformer or switch oil,   industrial cooling, an aqueous system of   air conditioning, a steam production system, a seawater evaporation system, a   hydrostatic heater or an aqueous heating system   cooling or cooling operation in a closed circuit. 26 1 4630   12. Composition according to claim 11 characterized in that it is based on an oil and in   what it contains in addition an anti-oxidant, a deactivation   metal, a corrosion or rust inhibitor, a viscosity index improver, a freezing point depressant, a dispersant, a surfactant and / or a friction reducer.   13. Composition according to claim 11 characterized in that it is water-based and in that it further contains an antioxidant, a corrosion inhibitor, a metal deactivator, a high-pressure additive or reducing agent. friction, a complexing agent, a precipitation inhibitor, a biocide, a substance buffer and / or antifoam.   14. Application of a combination of compounds of formulas (A) and (B) according to claim 1 as corrosion inhibitor for copper or copper alloys.