JP2018127661A - Process liquid and iron oxide removal method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel process liquid capable of selectively removing only iron oxide in a metal material, and capable of suppressing generation of rust even when standing the same without water washing, and an iron oxide removal method using the same.SOLUTION: The above described problem can be solved by a process liquid containing thiourea dioxide (A), a chelator having a group represented by the following formula (1):-N(CHCOOH)(1) or a chelator having a benzene ring structure having 2 hydroxyl groups or a salt thereof (B) and a nonionic surfactant (C).SELECTED DRAWING: None

Description

The present invention relates to a treatment liquid capable of removing iron oxide of a metal material and a method for removing iron oxide using the same.

Various techniques have been developed to remove metallic oxide iron oxide. For example, Patent Document 1 relates to an acid cleaning solution for a metal material, which comprises (A) a low molecular polyamine having an average molecular weight of 150 to 1500 and (B) a low molecular carboxylic acid (or a salt thereof) in an aqueous hydrochloric acid solution. Technology has been proposed.

JP2011-252220A

However, when the iron oxide in the metal material is removed using the acid cleaning solution for metal material of Patent Document 1 and left without being washed with water, rusting occurs immediately. Moreover, a metal iron material will be melt | dissolved after removal of an iron oxide. Therefore, the present invention can selectively remove only the iron oxide in the metal material, and after removing the iron oxide, a novel treatment liquid that can suppress the generation of rust even if left without being washed with water. And it aims at providing the iron oxide removal method using the same.

As a result of intensive studies to solve the above problems, the present inventor has obtained thiourea dioxide (A),
The following formula (1):
_{-N (CH 2 COOH) 2 (} 1)
A chelating agent having a group represented by the formula: or a chelating agent having a benzene ring structure having two hydroxy groups, or a salt thereof (B);
The non-surfactant (C) and the treatment liquid adjusted at a predetermined pH are brought into contact with the iron oxide of the oiled metal material to selectively remove the iron oxide, and then without washing with water. It has been found that the generation of rust can be suppressed even if left untreated, and the present invention has been completed.

That is, the present invention
(1) A treatment liquid for removing iron oxide from a metal material,
Thiourea dioxide (A),
The following formula (1):
_{-N (CH 2 COOH) 2 (} 1)
A chelating agent having a group represented by the formula: or a chelating agent having a benzene ring structure having two hydroxy groups, or a salt thereof (B);
A treatment liquid comprising a nonionic surfactant (C);
(2) A method for removing iron oxide, including a step of bringing the treatment liquid according to (1) into contact with iron oxide of a metal material;
Etc.

According to the present invention, it is possible to selectively remove only iron oxide in a metal material, and after removing the iron oxide, a novel process capable of suppressing the generation of rust even if left without being washed with water. A liquid and a method of removing iron oxide using the same can be provided.

Hereinafter, the treatment liquid and the iron oxide removal method using the same according to the present invention will be described in detail. In addition, this invention can be arbitrarily changed in the range including the summary, and is not limited only to the following embodiment.

[Treatment solution]
The treatment liquid of the present invention is an agent that removes iron oxide from metal materials such as black rust mainly composed of magnetite and red rust mainly composed of iron hydroxide. The treatment liquid of the present invention includes thiourea dioxide (A),
The following formula (1):
_{-N (CH 2 COOH) 2 (} 1)
A chelating agent having a group represented by the formula: or a chelating agent having a benzene ring structure having two hydroxy groups, or a salt thereof (B);
And a nonionic surfactant (C). By using this treatment liquid, the iron oxide of the metal material can be selectively removed, and the generation of rust can be suppressed even when left without being washed with water.

The chelating agent is not particularly limited as long as it has a group represented by the above formula (1) or has a benzene ring structure having two hydroxy groups. The chelating agent having a group represented by the above formula (1) is represented by, for example, RN (CH ₂ COOH) ₂ , and R is a carboxyalkyl group (the alkyl group is usually a C1-C6 alkyl group). A), a hydroxyalkyl group (the alkyl group is usually a C1-C6 alkyl group), or a di (carboxyalkyl) aminoalkyl group (each alkyl group is, independently of each other, usually a C1-C6 alkyl group). One of the two carboxyalkyl groups may be a hydroxyalkyl group.), [[Di (carboxyalkyl) amino] alkyl- (carboxyalkyl) amino] alkyl group or [[[di (carboxyalkyl) amino ] An alkyl- (carboxyalkyl) amino] alkyl- (carboxyalkyl) amino] alkyl group or Mention may be made of salt. Moreover, as a preferable aspect of the chelating agent having a benzene ring structure having the two hydroxy groups, a hydroxy group is bonded to two carbon atoms among the six carbon atoms in the benzene ring, and the remaining four A compound in which the following substituents are bonded to one or two of the carbon atoms. Examples of the substituent include an alkyl group (the alkyl group is usually a C1-C6 alkyl group), an alkoxy group (the alkoxy group is usually a C1-C6 alkoxy group), an aldehyde group, an alkylcarbonyl group (the alkyl group is C1 to C6 alkyl group), carboxyl group, carboxyalkyl group (alkyl group is usually C1 to C6 alkyl group), allyl group, alkyloxycarbonyl group (alkyl group is usually C1 to C6 alkyl group) ), A hydroxy group, a hydroxyalkyl group, a sulfo group, or an aminoalkyl group (the alkyl group is usually a C1-C6 alkyl group). Examples of the combination of two substituents include a combination of an aldehyde group and a hydroxy group, a combination of a sulfo group and a sulfo group, and the like.

Furthermore, the following formula (1):
_{-N (CH 2 COOH) 2 (} 1)
Specific examples of the chelating agent having a group represented by formula (I) or the chelating agent having a benzene ring structure having two hydroxy groups or a salt thereof (B) include, for example, ethylenediaminetetraacetic acid (EDTA), N- (2-hydroxy Ethyl) ethylenediamine-N, N ′, N′-triacetic acid (HEDTA), N- (2-hydroxyethyl) iminodiacetic acid (HIDA), diethylenetriaminepentaacetic acid (DTPA), nitrilotriacetic acid (NTA), triethylenetetramine -N, N, N ', N ", N''', N '''-hexaacetic acid (TTHA), 1,3-propanediamine-N, N, N ′, N′-tetraacetic acid (PDTA) Pyrogallol, 1,2,4-trihydroxybenzene, 4-methylcatechol, 4-methoxycatechol, 5-methylpyrogallol, 3,4-dihydroxybenzaldehyde 4-tert-butylpyrocatechol, 3,4,5-trihydroxybenzaldehyde, 2,3-dihydroxybenzaldehyde, 3 ′, 4′-dihydroxyacetophenone, 3,4-dihydroxybenzyl alcohol, 2,3,4 Trihydroxybenzaldehyde, 2,4,5-trihydroxybenzaldehyde, 4-allylpyrocatechol, 3,4-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 3-hydroxytyramine, methyl 3,4-dihydroxybenzoate, A compound such as 3,4-dihydroxyphenylacetic acid, 4,5-dihydroxy-1,3-benzenedisulfonic acid (Tiron) or a salt thereof may be mentioned, but is not limited thereto. Among these, one type may be used alone, or two or more types may be used in combination.

Examples of the salt of the chelating agent (B) include alkali metal salts, alkaline earth metal salts, hydrochlorides or ammonium salts, and specifically include lithium salts, sodium salts, potassium salts, and hydrochlorides. Or an ammonium salt etc. can be mentioned.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether (the alkyl group is usually a C6-C16 alkyl group), polyoxyethylene polyoxypropylene alkyl ether (the alkyl group is usually a C6-C16 alkyl group). Polyoxyethylene alkylaryl ether (the alkyl group is usually a C6-C16 alkyl group, and the aryl group is preferably a phenyl group), polyoxyethylene polyoxypropylene alkylaryl ether (the alkyl group is usually C6) To C16 alkyl group, and aryl group is preferably phenyl group), polyoxyethylene alkylamino ether (alkyl group is usually C6-C16 alkyl group), polyoxyethylene sorbitan fatty acid ester (common Monoester) (fatty acids are usually C12-C18 linear or branched saturated fatty acids), polyoxyethylene fatty acid esters (mono or diesters) (fatty acids are usually C12-C18 linear or branched) A saturated saturated fatty acid), ethylene oxide-propylene oxide copolymer, and the like, but is not limited thereto. Among these, one type may be used alone, or two or more types may be used in combination.

The HLB value of the nonionic surfactant is preferably 8 or more and 18 or less, and particularly preferably 10 or more and 16 or less. As the HLB in this specification, the one calculated by the Griffin method is used. The HLB by the Griffin method can be calculated by the following equation.
HLB = 20 × (molecular weight of hydrophilic portion / total molecular weight)

The mass concentration of thiourea dioxide (A) in the treatment liquid is not particularly limited, but is preferably 0.01 g / L or more with respect to the total amount of the treatment liquid, and is 0.1 g / L or more. More preferably, it is more preferably 1.0 g / L or more. The mass concentration of the chelating agent (B) is not particularly limited, and is preferably 0.1 g / L or more, and 0.5 g / L or more with respect to the total amount of the treatment liquid. It is more preferable that 1.0 g / L or more is contained. Moreover, the upper limit in the mass concentration of thiourea dioxide (A) is not particularly limited, but is preferably the maximum amount that does not precipitate thiourea dioxide (A) in terms of cost. The solid content mass concentration of the nonionic surfactant is not particularly limited, and is preferably in the range of 0.05 g / L to 10 g / L with respect to the total amount of the treatment liquid, 0.1 g / L More preferably, it is in the range of L to 5 g / L, more preferably in the range of 0.5 g / L to 2 g / L.

The treatment liquid according to the present invention includes an aqueous solvent, thiourea dioxide (A),
The following formula (1):
_{-N (CH 2 COOH) 2 (} 1)
A chelating agent having a group represented by the formula: or a chelating agent having a benzene ring structure having two hydroxy groups, or a salt thereof (B);
Although it will not restrict | limit especially if it contains nonionic surfactant (C), You may contain another component. Examples of other components include additives such as a pH adjuster, a rust preventive component, and an antifoaming agent.

Examples of the pH adjusting agent include pH raising agents such as aqueous sodium hydroxide, aqueous potassium hydroxide, and aqueous ammonia, and pH lowering agents such as carbon dioxide gas and aqueous nitric acid, but are not limited thereto. It is not something.

The pH of the treatment liquid according to the present invention is not particularly limited, but is preferably in the range of 6.0 to 12.5, and in the range of 8.5 to 12.5. Is more preferable, and about 11.0 is particularly preferable. In addition, the rusting after a process can be suppressed effectively by making pH into 6.0 or more. Further, when the pH is higher than 12.5, there is no change in the effect of removing iron oxide, but pH 12.5 or less is preferable from the viewpoint of cost and workability. Here, pH in this specification shows the value measured using the commercially available pH meter with respect to the process liquid of 45 degreeC.

Examples of the rust preventive component include N-containing basic compounds and other rust preventive additives, but are not limited thereto. The N-containing basic compound is not particularly limited as long as it is a basic compound containing an N atom in the molecule. For example, ammonia; hydrazine compound; hydroxylamine; monobutylamine, dibutylamine, tributylamine, Aliphatic amines such as monoethylamine, diethylamine, triethylamine, monomethylamine, dimethylamine, trimethylamine, propylamine, isopropylamine, hexylamine, 2-ethylhexylamine, ethylenediamine, diethylenetriamine, octylamine, naphthylamine; monoethanolamine, diethanolamine, Triethanolamine, methylethanolamine, dimethylethanolamine, diethylethanolamine, monoisopropanolamine, diisopropano Triethanolamine, alkanolamines such as triethanolamine and triisopropanolamine; amine having an alicyclic and / or aromatic ring; ammonium nitrite, nitrite such as sodium nitrite; and the like. Examples of other rust preventive additives include catechol, 3-methylcatechol, 3-methoxycatechol, resorcinol, hydroquinone, phenol, 3-aminophenol, pyrogallol, phloroglucinol, gallic acid, or salts thereof. It is done. Among these rust preventive additives, one kind may be used alone, or two or more kinds may be used in combination. By using this rust preventive component, rusting between processes can be further suppressed.

As the antifoaming agent, for example, a mineral oil-based defoaming agent, a fatty acid defoaming agent, a pluronic-type surfactant, a silicon-based defoaming agent and the like can be selected and used in a timely manner. Among these, one type may be used alone, or two or more types may be used in combination.

[Manufacture of processing solution]
The processing liquid of this invention can be manufactured by mix | blending said each component. For example, in an aqueous solvent, thiourea dioxide (A),
The following formula (1):
_{-N (CH 2 COOH) 2 (} 1)
A chelating agent having a group represented by the formula: or a chelating agent having a benzene ring structure having two hydroxy groups, or a salt thereof (B);
It can manufacture by mixing a nonionic surfactant (C) and the said 1 type, or 2 or more types of said additive as needed.

[Aqueous solvent]
The aqueous solvent in the present invention means a solvent containing 50% by mass or more of water based on the mass of all solvents. Examples of the solvent other than water contained in the aqueous solvent include alkane solvents such as hexane and pentane; aromatic solvents such as benzene and toluene; alcohol solvents such as ethanol, 1-butanol and ethyl cellosolve; tetrahydrofuran and dioxane Ether solvents such as ethyl acetate, butoxyethyl acetate, etc .; amide solvents such as dimethylformamide and N-methylpyrrolidone; sulfoxide solvents such as dimethyl sulfoxide; phosphate amides such as hexamethylphosphate triamide Solvent; and the like. These solvents other than water may be mixed alone or in combination of two or more. In addition, it is preferable to use only water from an environmental and economic viewpoint.

[Iron oxide removal method]
The iron oxide removal method according to the present invention includes a contact step of bringing the treatment liquid of the present invention into contact with iron oxide of a metal material. In addition, after a contact process, you may wash with water and it does not need to wash with water. Moreover, you may perform a drying process after a contact process or a water washing process.

[Contact process]
Examples of the treatment liquid contact method include, but are not limited to, a spray method, a dip method, or a combination thereof.

As for the contact condition of the treatment liquid, the temperature of the treatment liquid when contacting the treatment liquid is preferably in the range of 20 ° C. or more and 60 ° C. or less, and more preferably in the range of 35 ° C. or more and 45 ° C. or less. However, it is not limited to these temperatures. The contact time varies depending on the mass concentration of each component in the treatment liquid, but is usually in the range of 30 seconds to 600 seconds, and preferably in the range of 120 seconds to 240 seconds.

[Metal material]
The metal material to which the treatment liquid is applied is not particularly limited as long as it contains iron as a component and can form iron oxide on the surface, for example, a carbon steel plate, an alloy steel plate, a plated steel plate, and the like. Specifically, cold-rolled steel sheet, hot-rolled steel sheet, hot-dip galvanized steel sheet, aluminum-containing galvanized steel sheet, electrogalvanized steel sheet, alloyed galvanized steel sheet, zinc-nickel plated steel sheet, zinc-cobalt-plated steel sheet, vapor-deposited galvanized steel sheet, Known metal materials such as nickel-plated steel plates, tin-plated steel plates, and stainless steel plates can be used. The treatment liquid of the present invention is particularly useful for a metal material on which a thick iron oxide film is formed by arc welding or the like. The metal material may be oiled on the surface.

The iron oxide removal method of the present invention can be used for surface treatment of metal materials. Specifically, the surface treatment method of the metal material is not particularly limited as long as it includes the iron oxide removal step for performing the iron oxide removal treatment of the present invention, and the pretreatment step before the iron oxide removal step. The post-treatment process may be performed after the iron oxide removal process. As a pre-processing process, the degreasing process process which performs a degreasing process can be mentioned, for example. In addition, when performing a pre-processing process, you may perform a water-washing process between a pre-processing process and an iron oxide removal process. Moreover, you may perform a drying process between a pre-processing process and an iron oxide removal process, or between a washing process and an iron oxide removal process. Examples of the post-treatment step include a chemical conversion treatment step for forming a chemical conversion film on the surface of the metal material, a coating treatment step for forming a coating film on the surface of the metal material, and the like. These steps are sequentially performed. It is preferable. In addition, when performing a post-processing process after an iron oxide removal process, a water-washing process may be performed between each process, and a water-washing process may be performed between some processes. Moreover, after each process or the water washing process process, the drying process which dries the surface of a metal material may each be performed, and a one part drying process may be abbreviate | omitted.

The degreasing treatment can be performed, for example, by bringing a known acid degreasing agent or alkaline degreasing agent into contact with the surface of the metal material by a conventional method.

Examples of the chemical conversion treatment include known phosphate chemical conversion treatment, zirconium chemical conversion treatment, titanium chemical conversion treatment, hafnium chemical conversion treatment, and vanadium chemical conversion treatment. Specifically, it can be carried out by bringing a known chemical conversion treatment agent used in various chemical conversion treatments into contact with the surface of the metal material by a conventional method.

As the phosphate chemical conversion treatment, a known chemical conversion treatment with phosphate can be used. More specifically, a zinc phosphate treatment solution having a pH of 3.0 to 6.0 containing phosphate ions (0.1 to 50 g / L) and zinc ions (0.01 to 3.0 g / L). The surface of the metal material is brought into contact at 25 to 55 ° C. for 10 to 300 seconds. In addition, you may perform the surface adjustment process process for the purpose of the reactive improvement of a phosphate chemical conversion process with respect to a metal material just before a phosphate chemical conversion process process.

The surface conditioning treatment can be performed, for example, by bringing a treatment liquid containing a known divalent metal or trivalent metal phosphate into contact with the surface of the metal material by a conventional method.

As the zirconium chemical conversion treatment, a known chemical conversion treatment with a zirconium chemical conversion treatment agent can be used. Moreover, as said titanium chemical conversion treatment, the well-known chemical conversion treatment by a titanium chemical conversion treatment agent can be used. As the hafnium chemical conversion treatment, a known chemical conversion treatment with a hafnium chemical conversion treatment agent can be used. As the vanadium chemical conversion treatment, a known chemical conversion treatment with a vanadium chemical conversion treatment agent can be used. In these chemical conversion treatments, for example, the surface of the metal material is applied to a treatment solution having a pH of 3.0 to 6.0 containing zirconium ions, titanium ions, hafnium ions and / or vanadium ions at 0.005 to 5.0 g / L. It is performed by contacting at 25 to 55 ° C. for 10 to 300 seconds.

The coating treatment is performed after performing the iron oxide removing step or after performing one or more chemical conversion treatment steps. As a coating method, known methods such as electrodeposition coating (for example, cationic electrodeposition coating), solvent coating, and powder coating can be applied, but the method is not limited to these methods.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.

[Preparation of test piece]
<Metal material>
As the metal material, a hot-rolled mild steel sheet (SPHC: length 70 mm × width 150 mm × thickness 1.8 mm) standardized by JIS G3131 was used.

<Pretreatment for metal materials>
The metal material is immersed in an alkaline degreasing agent (trade name: Fine Cleaner E2093 (A agent 13 g / L, B agent 11 g / L), manufactured by Nippon Parkerizing Co., Ltd.) at 45 ° C. for 2 minutes, and the oil content on the surface of the metal material Removed dirt and dirt. Thereafter, the surface of the metal material was washed with water.

Next, after the metal material washed with water was heated at 400 ° C. for 20 minutes in a muffle furnace, it was taken out from the muffle furnace and radiated in the atmosphere to form artificial iron oxide on the surface of the metal material.

Subsequently, NOx-RUST530F (Parker Kosan) was applied to the artificial iron oxide as a rust preventive oil at 1.0 g / m ² and stored at 25 ° C. for 1 week.

<Iron oxide removal treatment for metal materials>
Each test shown in Table 3 is performed by immersing the pretreated metal material in various treatment liquids shown in Tables 1 and 2 (treatment liquids of Examples 1 to 25 and Comparative Examples 1 to 5) at 45 ° C. for a predetermined time. A piece was made. In addition, carbon dioxide gas or sodium hydroxide aqueous solution was used for pH adjustment of various process liquids.

The nine components shown in Tables 1 and 2 are as follows. Moreover, the unit with respect to the mass concentration (C1-C5 is solid content mass concentration) of each component shown in Table 1 and 2 is "g / L".
A1: Thiourea dioxide B1: Ethylenediaminetetraacetic acid B2: Nitrilotriacetic acid B3: Hydroxyethyliminodiacetic acid B4: 4,5-dihydroxy-1,3-benzenedisulfonic acid B5: 1-hydroxyethane-1,1-diphosphonic acid B6: ethylenediaminetetramethylenephosphonic acid C1: polyoxyalkylene alkyl ether (HLB value: 13)
C2: Polyoxyethylene polyoxypropylene alkyl ether (HLB value: 16)
C3: Polyoxyethylene polyoxypropylene alkyl aryl ether (HLB value: 10)
C4: Polyoxyethylene alkyl aryl ether (HLB value: 8)
C5: Polyoxyethylene polyoxypropylene alkyl ether (HLB value: 18)

[Evaluation of specimen]
<Iron oxide removal performance>
Each test piece (No. 1-30 test piece) taken out from the various treatment liquids was washed with water and dried by air blow. The surface of each test piece after drying was visually observed, and the iron oxide removal performance was evaluated according to the following evaluation criteria. The results are shown in Table 3.
(Evaluation criteria)
4: The removal of iron oxide was completely confirmed 3: The removal of most of the iron oxide was confirmed 2: The removal of a part of iron oxide was confirmed 1: No iron oxide was removed at all

<Rust inhibiting ability after iron oxide removal>
Each test piece (No. 1-30 test piece) taken out from the various treatment solutions was allowed to stand at 25 ° C. for 60 seconds, then washed with water and left standing. The surface of each test piece after standing was visually observed, and the ability to suppress rusting after iron oxide removal was evaluated according to the following evaluation criteria. The results are shown in Table 3.
(Evaluation criteria)
○: No rusting was confirmed ×: Rusting was confirmed

Claims (2)

A treatment liquid for removing iron oxide from a metal material,
Thiourea dioxide (A),
The following formula (1):
_{-N (CH 2 COOH) 2 (} 1)
A chelating agent having a group represented by the formula: or a chelating agent having a benzene ring structure having two hydroxy groups, or a salt thereof (B);
A nonionic surfactant (C);
A treatment liquid comprising: A method for removing iron oxide, comprising a step of bringing the treatment liquid according to claim 1 into contact with iron oxide of a metal material.