JPH10324982A - Corrosion and discoloration suppressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a corrosion and discoloration suppressor which does not contain nitrous acid capable of forming nitrosoamine harmful for health at all and is practicably effective to aluminum and iron by incorporating a specific aliphat. α- or β-dicarbonyl compd. and specific amines into this suppressor. SOLUTION: The corrosion and discoloration suppressor for Al and/or Fe is obtd. by incorporating >=1 kinds of the aliphat. α-dicarbonyl compd. expressed by formula I (Ra, Rb are H, 1 to 6C alkyl group, 2 to 5C alkenyl group or alkinyl group). The amines expressed by formula III (Ra, Rb, Rc are H, -OH, -NH2 , etc.) may be used by adding these amines to the aliphat. β-dicarbonyl compd. or the aliphat. β-dicarbonyl compd. expressed by formula II (Ra is H, 1 to 4C alkyl group, 2 to 4C alkenyl group, methoxy group, ethoxy group, Rb is H, 1 to 4C alkyl group, Rc is H, 1 to 3C alkyl group). The conventional suppressors, such as carboxylic acids, may be further added thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rust prevention technology, which does not contain nitrite which may generate harmful nitrosamines and has a remarkable effect of inhibiting corrosion and discoloration of aluminum and / or iron. It relates to a novel corrosion / discoloration inhibitor.

[0002]

2. Description of the Related Art It has long been known that β-diketone has an antirust effect on aluminum. For example,
Horiguchi et al. (Electrochemistry 34, 439 (196)
6)), Mihara's literature (Electrochemistry 37, 123 (196)
9)), a patent application for Nippon Kaishi Paper Co., Ltd.
-133471), S.P. M. Hassan reference (Co
rosion Science, Vol. 21, N
o. 06, pp 439 (1981)). However, β-diketones generally show acidity because the tautomerism of keto-enol is in equilibrium, and have a rust-preventive action and also cause an acid-induced corrosive action. There was a limit and it was not widely used.

[0003] On the other hand, no rust-preventing effect of α-diketone on aluminum is found in the literature.
n L. Horner et al. (Werkstoffe)
und Korrosion, 29, 654 (197)
8) describes the results of examining 446 types of compounds in order to find a compound having an antirust effect on aluminum, but does not describe α-diketone.

As a rust preventive for iron-based materials, those containing dicyclohexyl ammonium nitrite or diisopropyl ammonium nitrite as a main component are widely used. However, since dicyclohexylammonium nitrite and diisopropylammonium nitrite contain nitrite ions, it has been pointed out that carcinogenic nitrosamines may be generated. In some cases, and in some cases, adverse effects.

Further, the patent discloses an example in which it is disclosed that certain rust preventives for iron-based materials other than those widely used as described above also show an effect on aluminum. You can see. To name a few, for example,
Japanese Patent Application Laid-Open No. 50-15753 discloses a rust preventive comprising hexamethylenetetramine and sodium nitrite.
No. 54 discloses a rust inhibitor comprising hexamethylenetetramine and carboxylic acids or their salts and fatty acids.
19646 discloses a rust inhibitor comprising hexamethylenetetramine, sodium nitrite, an aromatic carboxylic acid or a salt thereof and a fatty acid, and JP-A-50-85535 discloses a rust inhibitor comprising an amine and a carboxylic acid or a salt or ester thereof. JP-A-50-91546 discloses a rust inhibitor comprising amines and amino acids or salts thereof.
Reference numeral 38 denotes a rust preventive comprising an ester of an amine and an aliphatic carboxylic acid or a salt thereof, and JP-A-50-93241 discloses a rust preventive comprising an amine and a dehydroacetic acid, nicotinic acid, ribofuran, calciferol, or a salt thereof. Japanese Unexamined Patent Publication No. 50-96440 discloses a rust preventive comprising an amine and an aldehyde or an alcohol. However, they also have a problem that they contain nitrite ions, and they do not provide a practically satisfactory effect.

As rust inhibitors for non-ferrous metals, benzotriazoles and their derivatives or imidazoles are mainly used in copper-based materials, and oximes and tetrazoles are also used. . For zinc, pyrazoles or aminotriazoles are used. Among them, benzotriazole for copper-based materials and the like are already known to exhibit some effects on aluminum, but the effects were not satisfactory for practical use.

[0007] As described above, the corrosion and discoloration inhibitors which do not contain nitrite which may generate harmful nitrosamines and have a remarkable corrosion and discoloration inhibitory effect on aluminum and / or iron are limited. I was

[0008]

SUMMARY OF THE INVENTION In view of this situation, there is no nitrous acid which may produce harmful nitrosamines, and a level which is practically satisfactory for aluminum and / or iron. It has been demanded to provide a practical corrosion / discoloration inhibitor having a remarkable corrosion / discoloration inhibitory effect.

[0009]

Means for Solving the Problems In view of the above-mentioned circumstances, the inventors of the present application have conducted extensive search for a corrosion / discoloration inhibitor which has a remarkable effect on aluminum and / or iron, and as a result, α -Dicarbonyl compound or α- or β-
It has been found that a corrosion / discoloration inhibitor containing a mixture of neutralizing the acidity of a carbonyl compound by adding an amine to a dicarbonyl compound and exhibiting a synergistic rust-preventive effect satisfies the above problems, The present invention has been completed.

As already mentioned, it has long been known that β-diketones have a certain rust-preventing effect on aluminum. This is thought to be due to the interaction with the metal by the chelating action of two C = O. However, the mechanism of action has not been studied in detail, and only the above-described chelating action has been considered vaguely. In addition, although there are many studies on β-diketones, no report has been found on α-diketones. As a result of the inventors' earnest research, β
-Among the diketones, as an example, two C = such as 1,3-cyclohexyldione shown in the formula (A)
A structure in which the angle formed by O is widely fixed has a small rust prevention effect.
It has been clarified that two C ＝ O, such as -acetylcyclopentanone, which can take a three-dimensional structure that is parallel or close thereto have a large rust-preventive effect.

Embedded image

Further, although α-diketones have not been studied so far, two C ＝ Os can always take such a parallel or nearly three-dimensional structure, so that they exhibit a large rust-preventive effect. all right.

A compound capable of taking such a steric structure is
Not only diketones, but also aldehydes having C ＝ O, lactones, esters, and the like have a rust preventive effect.

However, as described above, such β-dicarbonyl compounds generally show an acidity because the keto-enol tautomerism is in equilibrium, and have a rust-preventive action and an acid-induced corrosive action. Therefore, in the study using only β-diketone alone, it was judged that the rust preventive effect had a limit, and it was not practically used. On the other hand, the inventors of the present application use the mixture obtained by adding amines to such a dicarbonyl compound, thereby neutralizing the acidity of the compound and inhibiting the corrosion and discoloration of the amine. In addition to confirming that the excellent effect is exhibited, α which has not been studied before
As for the -dicarbonyl compound, it was found that the effect was excellent even when used alone or as an admixture with an amine as in the case of the β-dicarbonyl compound, and the above problem was solved. is there.

That is, the present invention provides a corrosion / discoloration inhibitor characterized by containing one or more compounds or mixtures selected from the following (A) to (C).

(A) one or more aliphatic α-dicarbonyl compounds represented by the following general formula (I):

(B) One or more of the aliphatic α-dicarbonyl compounds represented by the following general formula (I) are added with one or more of the amines represented by the following general formula (III): One or more of a mixture of

(C) One or more kinds of aliphatic β-dicarbonyl compounds represented by the following general formula (II) are added with one or more kinds of amines represented by the following general formula (III): One or more kinds of mixtures consisting of

General formula (I)

Embedded image [Where Ra and Rb may be the same or different,
Represents hydrogen or a C ₁ -C ₅ alkyl group, a C ₂ -C ₅ alkenyl group or a C ₂ -C ₅ alkynyl group, or the carbon atoms of Ra and Rb are bonded to form a 5- or 6-membered ring; May be formed. ] The aliphatic α-dicarbonyl compound represented by the formula:

General formula (II)

Embedded image [Wherein, Ra is hydrogen or an alkyl group of C ₁ ~C _4, C
Represents an alkenyl group, a methoxy group or an ethoxy group of ₂ to ₄ carbon atoms; Rb represents hydrogen or an alkyl group of ₁ to ₄ carbon atoms;
Rc represents hydrogen or an alkyl group C ₁ -C _3. The Ra
And Rc or / and Rb and Rc may combine to form a 5- or 6-membered ring. ] Represented by the aliphatic β-
Dicarbonyl compounds.

General formula (III)

Embedded image [Wherein, Ra, Rb and Rc are each independently _{hydrogen, -OH, -NH 2, -CH 2} CH 2 NH 2, -CH
_{2 CH 2 NHCH 2 CH 2 NH} 2, a phenyl group, a benzyl group, a naphthyl group, an alkyl group of C ₁ ~C _22, C ₂ ~C
_{22 represents} an alkenyl group or a C ₂ -C ₂₂ alkynyl group, wherein the terminal hydrogen of the alkyl group, the alkenyl group or the alkynyl group may be replaced by —OH or —NH ₂ , or the carbon atoms of Ra and Rb The atoms may be bonded together or via an oxygen or nitrogen atom to form a 5- or 6-membered ring. Amines represented by the formula:

[0021]

Preferred examples of the α-dicarbonyl compound represented by the general formula (I) used as a component of the corrosion / discoloration inhibitor of the present invention include glyoxal, pyrualdehyde, diacetyl, and diacetyl. , 3-pentanedione,
3,4-hexanedione, 3,4-heptanedione,
3,4-octanedione, 4,5-nonanedione, 4,
5-decandione, 5,6-undecandione, 1,2
-Cyclohexanedione and the like.

Preferred examples of the β-dicarbonyl compound represented by the general formula (II) used as a component of the corrosion / discoloration inhibitor of the present invention include acetylacetone, 2,4-hexanedione, 2,4 -Heptanedione, 2,4-octanedione, 3,5-octanedione, 4,6-decandione, 5,7-undecandione, methyl acetoacetate, ethyl acetoacetate, 3-methyl-2,4
-Pentanedione, 2-acetylcyclopentanone, α
-Acetyl-γ-butyrolactone, 2-ethylcarbonylcyclopentanone, α-ethylcarbonyl-γ-butyrolactone, 2-propylcarbonylcyclopentanone, α-propylcarbonyl-γ-butyrolactone, 2
-Butylcarbonylcyclopentanone, α-butylcarbonyl-γ-butyrolactone, 2-acetylcyclohexanone, α-acetyl-δ-pentyrolactone, 2-ethylcarbonylcyclohexanone, α-ethylcarbonyl-γ-pentyrolactone, 2- Propylcarbonylcyclohexanone, α-propylcarbonyl-γ-pentyrolactone, 2-butylcarbonylcyclohexanone,
α-butylcarbonyl-γ-pentyrolactone and the like.

Further, among the amines represented by the general formula (III) used as a component of the corrosion / discoloration inhibitor of the present invention, preferred examples include mono (or di, tri) methylamine and mono (or Di (tri) ethylamine, mono (or di, tri) n- (or i-) propylamine, mono (or di, tri) n- (or i-, t-) butylamine, mono (or di) pentylamine ( Amyl or isoamyl)
Amine, mono (or di) hexylamine, mono (or di) cyclohexylamine, dodecylamine, hexadecylamine, octadecylamine, hydrazine, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, mono (or di, tri) Ethanolamine, mono (or di, tri) n- (or i-) propanolamine, diallylamine, propargylamine, 1,1-dimethylpropargylamine,
Examples include benzylamine, aniline, di (or tri) phenylamine, 2-naphthylamine, mono (or di) phenylhydrazine, morpholine and the like.

Although we do not want to be bound by any particular theory as to the effect of the addition of the amine in the present invention, the amine is represented by the following reaction formula:

Embedded image It is considered that, as indicated by, it acts on the diketone to form (e) and shifts the equilibrium to the right so as to trap the protons of the enol compound (d) showing the acidity of the diketone. Depending on the combination of the diketone and the amine, a mixture of the two may give a crystalline or oily product, but even such a crystalline or oily substance shows volatility. It is considered that the formation of a crystalline or oily substance is not an irreversible reaction, but is in an equilibrium state, and is vaporized as diketone and amine. The reaction between (d) and (e) is an equimolar reaction, but the substance exhibiting the action of inhibiting corrosion and discoloration is not (e), but the meaning of the addition of the amine is itself. And the above-mentioned shift of the equilibrium together with the action of inhibiting corrosion and discoloration. Therefore, the mixing ratio of the mixture of the present invention is not necessarily limited to equimolar, and the effect can be exhibited in a wide mixing ratio. In this sense, herein the α- and / or β- according to the invention are used.
An addition mixture of a dicarbonyl compound and an amine in a wide mixing ratio is particularly referred to as a "mixture obtained by adding an amine to a dicarbonyl compound". Therefore, when the mixing ratio (by weight) of the α- and / or β-dicarbonyl compound and the amine constituting the present invention is from 10 to 90:90 to 10, the intended effect of inhibiting corrosion and discoloration is exhibited. , More preferably 3
The mixing ratio is from 0 to 70:70 to 30.

The present invention relates to a mixture comprising an α- and / or β-dicarbonyl compound and an amine added thereto, and / or
-A known corrosion / discoloration inhibitor can be added to a corrosion / discoloration inhibitor containing a dicarbonyl compound for use. These known corrosion / discoloration inhibitors include carboxylic acids, phosphonic acids and their amides, esters or amine salts and / or alkali metal salts, nitro compounds, dithiocarbamic acids, benzotriazoles, alkylaminotriazoles, There are thiazoles, imidazolidinones, pyrazoles, imidazoles, hydantoins, thiadiazoles, anisidines, benzoxazoles, indoles, thiazolines, tetrazoles and sugars such as starch, sucrose, glucoside and the like. One or more known compounds including these may be added to provide a synergistic effect for use.

Examples of such compounds include carboxylic acids, phosphonic acids and amides, esters or amine salts of these acids and / or alkali metal salts, and compounds suitable as nitro compounds include benzoic acid and 2-mercaptobenzoic acid. , 4-n- (or i-, t-) butylbenzoic acid, isopropylbenzoic acid, 2-chlorobenzoic acid, 3-
Chlorobenzoic acid, 4-chlorobenzoic acid, 2-aminobenzoic acid, 3-aminobenzoic acid, 4-aminobenzoic acid, 2-
Methoxybenzoic acid, 4-methoxybenzoic acid, 2,6-dimethoxybenzoic acid, 3-hydroxybenzoic acid, 4-hydroxybenzoic acid, 2,6-hydroxybenzoic acid, 3,
4,5-trihydroxybenzoic acid, 2-nitrobenzoic acid, 3-nitrobenzoic acid, 4-nitrobenzoic acid, 3,5
-Dinitrobenzoic acid, 3-methoxy-2-nitrobenzoic acid, 1-naphthoic acid, 2-naphthoic acid, toluic acid, salicylic acid, cinnamic acid, butyric acid, 1-naphthaleneacetic acid, 2-ethylbutyric acid, cyclohexyl carboxylic acid, capron Acid, 2-ethylhexanoic acid, caprylic acid, oleic acid, capric acid, lauric acid, malonic acid, succinic acid, maleic acid, fumaric acid, sorbic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, malic acid , Ethylphosphonic acid, butylphosphonic acid, hexylphosphonic acid and their amides, esters, amine salts and / or alkali metal salts.

Compounds suitable as dithiocarbamic acids include diethyldithiocarbamate, dimethyldithiocarbamate, N-methyldithiocarbamate, ethylene-bisdithiocarbamate, dithiocarbamate, dibutyldithiocarbamate, diamildithiocarbamate. And dibenzyldithiocarbamate.

Compounds suitable as benzotriazoles include benzotriazole, 1-methylbenzotriazole, 4-methylbenzotriazole, 1-ethylbenzotriazole, 1-hydroxybenzotriazole,
4-carboxybenzotriazole, 1-chlorobenzotriazole, 5-chlorobenzotriazole, N-acetyl-benzotriazole, N-butyryl-benzotriazole, N-pivaloyl-benzotriazole, N
-Nonanoyl-benzotriazole, N-caproyl-
Benzotriazole, N-caprylyl-benzotriazole, N-lauroyl-benzotriazole, N-stearyl-benzotriazole, N-oleoyl-benzotriazole, naphthotriazole, tolyltriazole, 2- (2'-hydroxy-5'-methyl Phenyl)
Benzotriazole, 2- (2′-hydroxy-3,
5′-di-tert-butylphenyl) benzotriazole, (di) ethylaminomethylbenzotriazole,
(Di) butylaminomethylbenzotriazole, (di)
Octylaminomethylbenzotriazole, (di) tridecylaminomethylbenzotriazole, (di) octadecylaminomethylbenzotriazole, (di) cyclohexylaminomethylbenzotriazole, (di) allylaminomethylbenzotriazole, (di) benzylaminomethylbenzo Triazole, (di) octylaminoethylbenzotriazole, (di) octylaminodecylbenzotriazole, (di) octylaminobenzylbenzotriazole and the like.

Compounds suitable as alkylaminotriazoles include 3-amino-1,2,4-triazole, 3-amino-5-methyl-1,2,4-triazole, 3-amino-5-ethyl- 1,2,4-triazole, 3-amino-5-propyl-1,2,4-triazole, 3-amino-5-butyl-1,2,4-triazole, 3-amino-5-pentyl-1, 2,4-triazole, 3-amino-5-hexyl-1,2,4-triazole, 3-amino-5-heptyl-1,2,4-triazole, 3-amino-5-octyl-1,2,2 4-
Triazole, 3-amino-5-nonyl-1,2,4-
Triazole, 3-amino-5-decyl-1,2,4-
Triazole, 3-amino-5-undecyl-1,2,2
4-triazole, 3-amino-5-dodecyl-1,
2,4-triazole and the like can be mentioned.

Compounds suitable as benzothiazoles include 2-methylbenzothiazole, 2-mercaptobenzothiazole, 2- (4'-morpholinodithio) benzothiazole, N-cyclohexyl-2-benzothiazolylsulfenamide, N-oxydiethylene-2-benzothiazolylsulfenamide, N-tert-butyl-2-benzothiazolylsulfenamide and the like can be mentioned.

Compounds suitable as imidazolidinones include ethylene urea, 4,5-dihydroxyethylene urea, N, N'-dimethylethylene urea, N, N'-diethanolethylene urea, and N, N'-dipropanol. Ethylene urea, N, N'-dimethyl-4,5-dihydroxyethylene urea, N, N'-diethyl-4,5-dihydroxyethylene urea, N, N'-diethanol-4,5-
Examples include dihydroxyethylene urea, N, N'-dipropanol-4,5-dihydroxyethylene urea and the like.

Compounds suitable as pyrazoles include 3
-Methyl-5-hydroxypyrazole, 4-amino-
3,5-dimethylpyrazole, 1-hydroxymethyl-
3,5-dimethylpyrazole, 3,5-dihexylpyrazole, 3,5-dipropyl-1-methoxycarbonylpyrazole, 3,5-dimethylpyrazole-1-carboxamide, 3,5-didecylpyrazole, 3,5- Dihydroxymethylpyrazole, 3-methyl-5-pyrazolone, 1,3-dimethyl-5-pyrazolone, 3,5-dimethylpyrazole, pyrazole, 3-phenyl-5-pyrazolone, 3-methyl-5-phenylpyrazole, 4-
Phenylpyrazole and the like.

Compounds suitable as imidazoles include:
2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-propylimidazole, 2-phenyl-5-iodoimidazole, 2-benzylimidazole, 2-benzyl-4-methylimidazole, 2- (3 -Chloro) benzylimidazole, 2-
(3-iodo) benzylimidazole, 2-naphthylimidazole, 2-naphthyl-4-methylimidazole,
2-naphthyl-4-methyl-5-bromoimidazole,
2- (3,5-dibromo) naphthylimidazole, 2-
(2,6-dichloro) naphthyl-4-methylimidazole, 2-mercaptobenzimidazole, 2-mercaptomethylbenzimidazole, 2-amylimidazole, 2-heptylimidazole, 2-decylimidazole, 2-undecylimidazole, 2- Dodecylimidazole, 2-tridecylimidazole, 2-tetradecylimidazole, 2-heptadecylimidazole, 2-
Undecyl-4-methylimidazole, 2-heptadecyl-4-methylimidazole and the like can be mentioned.

Compounds suitable as hydantoins include:
3- (γ-aminopropyl) hydantoin, 3- (γ-
Aminopropyl) -5-methylhydantoin, 3- (γ
-Aminopropyl) -5,5-dimethylhydantoin,
1,3-di- (γ-aminopropyl) hydantoin,
1,3-di- (γ-aminopropyl) -5-methylhydantoin, 1,3-di- (γ-aminopropyl) -5
5-dimethylhydantoin, 1,3,7-triazacyclo- [4,3,0] non-7-en-2-one, 9-methyl-1,3,7-triazacyclo- [4,3,0] nona -7-en-2-one, 9,9'-dimethyl-1,
3,7-triazacyclo- [4,3,0] non-7-en-2-one, 1- (γ-aminopropyl) -1,3,3
7-triazacyclo- [4,3,0] non-7-ene-
2-one, 1- (γ-aminopropyl) -9-methyl-
1,3,7-Triazacyclo- [4,3,0] nona-7
-En-2-one, 1- (γ-aminopropyl) -9,
9'-di-methyl-1,3,7-triazacyclo-
[4,3,0] non-7-en-2-one and the like.

Compounds suitable as thiadiazoles include 3,5-di-butyldithiothiadiazole,
5-t-hexyldithiothiadiazole, 3,5-di-octyldithiothiadiazole, 3,5-di-lauryldithiothiadiazole, 3,5-di-oleyldithiothiadiazole, 2-amino-1,3,4 -Thiadiazole, 2,5-dimercaptothiadiazole and the like.

Compounds suitable as anisidines include m
-Anisidine, o-anisidine, p-anisidine and the like.

Suitable compounds as benzoxazoles include 2-benzoxazole thiol.

Compounds suitable as dithiocarbamic acids include diethyldithiocarbamate, dimethyldithiocarbamate, N-methyldithiocarbamate, ethylene-bisdithiocarbamate, dithiocarbamate, dibutyldithiocarbamate, and diamildithiocarbamate. And dibenzyldithiocarbamate.

Compounds suitable as thiazolines include 2
-Mercaptothiazoline and the like.

Compounds suitable as tetrazoles include:
1-phenyl-5-mercaptotetrazole, 3-bromide
(4,5 dimethyl-2-thiazolyl) -2,5-diphenyl 2H-tetrazolium, 5-amino-1H-tetrazole and the like.

Compounds suitable as sugars such as starch, sucrose, glucoside and the like include dextrin, cellulose, glucose, mannose, allose, altrose, growth, ribose, arabinose, fructose, rhamnose, galactose, maltose, lactose, rafitose, Glucosidase, gelatin, maltitol, sorbitol, lactitol, erythritol, inulin,
Glycogen and the like.

Preferable examples of other compounds include thiourea, thioacetamide, thiosemicarbazide, thiophenol, p-thiocresol, thiobenzoic acid, didodecyltrithiocarbonate, didodecyldecane-1,10 -Dithiolate and the like.

The corrosion / discoloration inhibitor obtained from the mixture of the α-dicarbonyl compound and / or the α- and / or β-dicarbonyl compound constituting the present invention to which amines are added, and a part thereof are described above. Known carboxylic acids exemplified,
Phosphonic acids and their amides, esters or amine salts and / or alkali metal salts, nitro compounds, dithiocarbamic acids, benzotriazoles, alkylaminotriazoles, benzothiazoles, imidazolidinones, pyrazoles, imidazoles, hydantoins The addition ratio (by weight) of thiadiazoles, anisidines, dithiocarbamic acids, thiazolines and the like is appropriately selected according to the purpose, but is generally from 10 to 90:90 to
10, a good rust-preventing effect is exhibited.
0 to 70: 70 to 30.

The compounds and / or compositions of the present invention not only have a corrosion inhibiting, discoloring preventing and rust inhibiting effect on aluminum and iron or their alloy materials, but also have a silver , Copper, zinc and their alloy materials also exhibit the effect, so that the embodiment is not limited to aluminum and iron,
It can be applied to other metals and alloys.

The compound and / or composition of the present invention can be used in any form such as bulk, solution, pellets, and the like. When the solution is used, water, oil, alcohols, glycols, other organic solvents or It can be used by dissolving it in a mixed solvent of water / organic solvent or dissolving it with asphalt, wax, petrolactam, resin and the like. Aluminum, silver, copper,
In addition to immersing metal materials such as zinc and iron, the effect can be easily exerted only by immersion and air drying. Or,
In addition, the solution is applied to paper, cloth, non-woven fabric, plastic,
Organic and inorganic substrates such as glass, zeolite or silica gel, and adsorbents can be impregnated, coated, kneaded and used. Alternatively, it is also possible to mix in an adhesive and apply it before use. That is, for example, pickling, polishing, an inhibitor effect in a surface treatment agent such as etching,
Not only for the primary purpose of corrosion prevention, discoloration prevention and rust prevention effect, but also for the secondary purpose, such as the rust prevention effect of processing agents such as cutting oil and press oil or hydraulic oil. It can also be used for applications where

Further, the corrosion / discoloration inhibitor of the present invention is used in a surfactant, so that the above-mentioned operations, that is, dissolution, impregnation, coating, kneading, etc., can be easily carried out, and the effect can be easily exhibited.
A lubricant or the like can be added for use.

[0047]

EXAMPLES The effects of the corrosion and discoloration inhibitor of the present invention on corrosion and discoloration will be described below with reference to examples.

COMPARATIVE EXAMPLE 1 One side of a 60 × 60 × 1 mm aluminum plate (1050P) was polished with # 400 emery paper to obtain 20 ml.
Placed in the upper part of a 2 liter plastic container containing 0.5 g of a corrosion / discoloration inhibitor composition in a petri dish, and kept at 30 ° C. for 20 hours after sealing. The sample was kept at 30 ° C. for 3 days while cooling at, and a vaporization rust prevention test on aluminum was performed. As a rust inhibitor for reference, (1) sodium nitrite + hexamethylenetetramine (2) benzoic acid + dicyclohexylamine was used.

Example 1 Under the same conditions as in Comparative Example 1, a vaporizable rust-proof test was performed on aluminum using the following compounds (3) to (40), mixtures or compositions.

(3) glyoxal,

(4) pyruvaldehyde,

(5) Diacetyl

(6) 3-methyl-1,2-cyclopentanedione,

(7) 3,4-hexanedione,

(8) 1,2-cyclohexanedione,

(9) Mono-i- is added to 50 parts of glyoxal
A mixture obtained by adding 50 parts of propanolamine,

(10) A mixture obtained by adding 10 parts of hydrazine to 90 parts of 3,4-hexanedione;

(11) 1,2-cyclohexanedione 5
A mixture obtained by adding 50 parts of di-i-propanolamine to 0 parts,

(12) 1,2-cyclohexanedione 9
A mixture obtained by adding 10 parts of hydrazine to 0 parts,

(13) A composition in which 30 parts of glyoxal and 70 parts of diethyldithiocarbamate are mixed,

(14) A composition comprising 40 parts of diacetyl and 60 parts of 2-phenylimidazole,

(15) A composition comprising 90 parts of diacetyl and 10 parts of sorbitol,

(16) A composition obtained by mixing 40 parts of 3-methyl-5-hydroxypyrazole with 60 parts of 3,4-hexanedione,

(17) 1,2-cyclohexanedione 6
A composition obtained by mixing 40 parts of benzotriazole with 0 parts,

(18) Mono-i is added to 60 parts of glyoxal.
8 of a mixture obtained by adding 40 parts of propanolamine.
A composition obtained by mixing 20 parts of 3-amino-1,2,4-triazole in 0 parts,

(19) A composition obtained by adding 50 parts of 5,6-undecandione and 50 parts of di-i-propanolamine to 80 parts of a mixture obtained by mixing 20 parts of 2-mercaptobenzothiazole,

(20) 1,2-cyclohexanedione 9
A composition obtained by mixing 50 parts of ethylene urea with 50 parts of a mixture obtained by adding 10 parts of hydrazine to 0 parts,

(21) A composition in which 30 parts of propargylamine is added to 70 parts of 2,3-pentanedione, and 80 parts of a mixture obtained by mixing 20 parts of 3- (γ-aminopropyl) hydantoin is used.

(22) Di-n is added to 50 parts of acetylacetone.
A mixture obtained by adding 50 parts of propylamine,

(23) Di-n is added to 50 parts of acetylacetone.
A mixture obtained by adding 50 parts of butylamine;

(24) Di-i is added to 50 parts of acetylacetone.
A mixture comprising 50 parts of propanolamine,

(25) A mixture obtained by adding 50 parts of cyclohexylamine to 50 parts of acetylacetone,

(26) A mixture obtained by adding 60 parts of triethanolamine to 40 parts of acetylacetone,

(27) 2-acetylcyclopentanone 4
A mixture obtained by adding 60 parts of di-n-hexylamine to 0 parts,

(28) 2-acetylcyclopentanone 5
A mixture obtained by adding 50 parts of di-i-propanolamine to 0 parts,

(29) 2-acetylcyclopentanone 5
A mixture obtained by adding 50 parts of di-n-butylamine to 0 parts,

(30) 2-acetylcyclohexanone 5
A mixture obtained by adding 50 parts of triethanolamine to 0 parts,

(31) A mixture obtained by adding 10 parts of di-n-butylamine to 90 parts of α-acetyl-γ-butyrolactone;

(32) A composition obtained by adding 50 parts of morpholine to 50 parts of acetylacetone and mixing 50 parts of 3,5-di-butyldithiothiadiazole with 50 parts of the mixture.

(33) Di-n is added to 60 parts of acetylacetone.
A composition obtained by mixing 30 parts of o-anisidine with 70 parts of a mixture obtained by adding 40 parts of -butylamine,

(34) A composition in which 70 parts of 2-methylbenzothiazole is mixed with 30 parts of a mixture obtained by adding 70 parts of benzylamine to 30 parts of acetylacetone,

(35) A composition obtained by adding 30 parts of 2-benzoxazolethiol to 70 parts of a mixture obtained by adding 40 parts of cyclohexylamine to 60 parts of 5,7-undecandione;

(36) A composition comprising a mixture of 50 parts of α-propylcarbonyl-γ-pentyrolactone and 50 parts of triethanolamine mixed with 30 parts of dimethyldithiocarbamate,

(37) 2-acetylcyclopentanone 5
A composition obtained by mixing 30 parts of thioacetamide with 70 parts of a mixture obtained by adding 50 parts of di-i-propanolamine to 0 parts,

(38) A composition in which 50 parts of 2-butylcarbonylcyclohexanone and 50 parts of dodecylamine are added, and 20 parts of the mixture is mixed with 80 parts of sodium benzoate.

(39) 2-acetylcyclohexanone 7
A composition obtained by mixing 20 parts of 2-mercaptothiazoline with 80 parts of a mixture obtained by adding 30 parts of diethylenetriamine to 0 parts,

(40) A composition obtained by adding 50 parts of di-n-butylamine to 50 parts of α-acetyl-γ-butyrolactone and mixing 70 parts of 1-phenyl-5-mercaptotetrazole with 70 parts of the mixture.

Table 1 compares the results of Comparative Example 1 and Example 1.
It was shown to. The compounds, mixtures or compositions of the examples exhibited better corrosion protection than the compounds, mixtures or compositions of the comparative examples.

[0089] Comparative Example 2 225 ml 0.5 wt% glass bottle of corrosion and discoloration inhibitors Cl ^-, HCO ₃ ^-, each of SO ₄ ^2-ions 100pp
Put 200 g of aqueous solution containing 50 m, 50 x 30 x 2.0 mm
Aluminum plate (2024P) was entirely polished with # 400 emery paper, and immersed completely in the solution.
It was hung and covered. It was kept at 50 ° C. for one week, and a total immersion corrosion inhibition test on aluminum was performed. (1) and (2) described in Comparative Example 1 as corrosion / discoloration inhibitors
Was used.

Example 2 Under the same conditions as in Comparative Example 2, the compound described in Example 1
Of the mixture or composition, (5), (6), (8), (1)
Using 1), (15) and (31), a total immersion corrosion inhibition test on aluminum was performed.

Table 2 compares the results of Comparative Example 2 and Example 2.
It was shown to. The compounds, mixtures or compositions of the examples exhibited better corrosion protection than the compounds, mixtures or compositions of the comparative examples.

Comparative Example 3 In accordance with JIS-Z1519, a volatilization rust prevention test was performed on iron and steel with the amount of the corrosion / discoloration inhibitor being 0.05 g, which was double the amount of 0.1 g, as specified. (1) and (2) described in Comparative Example 1 were used as corrosion / discoloration inhibitors.

Example 3 Under the same conditions as in Comparative Example 3, (3) to (3) described in Example 1 above.
Using the compound, mixture or composition of (40), a volatilization rust prevention test on steel was performed.

The results of Comparative Example 3 and Example 3 were compared, and the results of Comparative Example 1 and Example 1 are also shown in Table 1 showing the results. The compounds, mixtures or compositions of the examples showed good or equivalent corrosion protection compared to the compounds, mixtures or compositions of the comparative examples.

Comparative Example 4 As the corrosion / discoloration inhibitor composition, (1) and (2) described in Comparative Example 1 were used. A 25 × 25 mm silver plate polished with # 400 emery paper is immersed in a 5 wt% aqueous solution of the corrosion / discoloration inhibitor composition for 1 minute, washed with water, and dried, and subjected to a hydrogen sulfide atmosphere according to JEIDA-41. The sample was hung in a desiccator, kept at room temperature for 4 hours, and subjected to an immersion rust prevention test for silver.

Example 4 Under the same conditions as in Comparative Example 4, immersion in silver using (8), (21), (29) and (34) of the compound, mixture or composition described in Example 1 above A rust prevention test was performed.

Table 3 compares the results of Comparative Example 4 and Example 4.
It was shown to. The compounds, mixtures or compositions of the examples exhibited better corrosion protection than the compounds, mixtures or compositions of the comparative examples.

As can be seen from the results shown in Tables 1 to 3, the product of the present invention exhibits a good corrosion / discoloration inhibitory effect on aluminum with respect to the conventional corrosion / discoloration inhibitor, and also has an effect on steel or silver. Excellent corrosion / discoloration suppression effect was exhibited.

[0099]

[Table 1]

[0100]

[Table 2]

[0101]

[Table 3]

[0102]

According to the present invention, an α-dicarbonyl compound and / or an α- or β-dicarbonyl compound are required to neutralize the acidity of the carbonyl compound and to exert a synergistic corrosion / discoloration inhibiting effect. By using a mixture obtained by adding an amine, aluminum has a remarkable effect to a level practically satisfactory for aluminum, and also has a corrosion / discoloration inhibiting effect satisfactory for iron-based materials, and is healthy. It has become possible to provide a practical corrosion / discoloration inhibitor containing no nitrous acid, which may generate harmful nitrosamines.

Continued on the front page (72) Inventor Akihiro Sagawa 21-8 Minami-Futami, Futami-cho, Akashi-shi, Hyogo Inside the Daiwa Kasei Research Laboratories (72) Inventor Keigo Obata 21-8 Minami-Futami, Futami-cho, Akashi-shi, Hyogo Daiwa Kasei In the laboratory

Claims (3)

[Claims] 1. A corrosion / discoloration inhibitor comprising one or more compounds or mixtures selected from the following (A) to (C): (A) a compound represented by the following general formula (I): One or more aliphatic α-dicarbonyl compounds represented by the following general formula (III): (B) one or more aliphatic α-dicarbonyl compounds represented by the following general formula (I) And (C) an aliphatic β represented by the following general formula (II):
One or more of a mixture of one or more of dicarbonyl compounds and one or more of amines represented by the following general formula (III); and a general formula (I) ] [Where Ra and Rb may be the same or different,
Represents hydrogen or a C ₁ -C ₅ alkyl group, a C ₂ -C ₅ alkenyl group or a C ₂ -C ₅ alkynyl group, or the carbon atoms of Ra and Rb are bonded to form a 5- or 6-membered ring; May be formed. An aliphatic α-dicarbonyl compound represented by the general formula (II): [Wherein, Ra is hydrogen or an alkyl group of C ₁ ~C _4, C
Alkenyl group ₂ -C ₄ represents a methoxy group or an ethoxy group, Rb represents hydrogen or an alkyl group C ₁ -C _4, Rc represents hydrogen or an alkyl group C ₁ -C _3. The carbon atoms of Ra and Rc or / and Rb and Rc may combine to form a 5- or 6-membered ring. An aliphatic β-dicarbonyl compound represented by the following general formula (III): [Wherein, Ra, Rb and Rc are each independently _{hydrogen, -OH, -NH 2, -CH 2} CH 2 NH 2, -CH
_{2 CH 2 NHCH 2 CH 2 NH} 2, a phenyl group, a benzyl group, a naphthyl group, an alkyl group of C ₁ ~C _22, C ₂ ~C
_{22 represents} an alkenyl group or a C _{2 to} C ₂₂ alkynyl group, wherein the terminal hydrogen of the alkyl group, the alkenyl group or the alkynyl group may be substituted by —OH or —NH ₂ , or the carbon atoms of the Ra and Rb The atoms may be bonded together or via an oxygen or nitrogen atom to form a 5- or 6-membered ring. Amines represented by the formula: 2. Carboxylic acids, phosphonic acids and their amides, esters or amine salts or / and alkali metal salts, nitro compounds, dithiocarbamic acids,
Benzotriazoles, alkylaminotriazoles, benzothiazoles, imidazolidinones, pyrazoles, imidazoles, hydantoins, thiadiazoles, anisidines, benzoxazoles, indoles, thiazolines, tetrazoles and starch, sucrose, The corrosion / discoloration inhibitor according to claim 1, further comprising one or more compounds selected from saccharides such as glucosides. 3. The corrosion / discoloration inhibitor according to claim 1, wherein the corrosion / discoloration inhibitor comprises a solid (bulk), a solution, or a solid formed by impregnating, coating, kneading, or the like on a support.