JP6051423B2 - Zinc plating bath additive, zinc plating bath, galvanized film forming method, and additive manufacturing method - Google Patents

Description

  The present invention relates to a galvanizing bath additive capable of preventing abnormal precipitation at a high current density.

  As alkaline galvanizing baths for forming galvanized films, cyan baths and zincate baths are known. From the viewpoint of environmental problems, zincate baths are used more than cyan baths. It was. However, since the formation rate of the zinc plating film by the zincate bath is slow, it is desired to increase the formation rate of the zinc plating film by the zincate bath. In addition, when a galvanized film is formed in a galvanizing bath, the current density in the plating bath increases locally due to the shape of the object to be plated, and abnormal deposition on the plated film occurs at locations where the current density is high. May occur. For this reason, development of a galvanizing bath additive capable of preventing the abnormal deposition of the plating film has been promoted even when the current density is locally increased. The following patent document describes an example of such a galvanizing bath additive.

Japanese Patent Laying-Open No. 2015-30866

By using the galvanizing bath additive described in the above patent document, it is possible to prevent abnormal deposition of the plating film even when the current density is locally increased to some extent. However, when a plating film is formed on a hooking jig such as a rack, the current density of the protruding portion such as the tip of the hooking part of the jig may be 50 A / dm ² or more. At a high current density, abnormal deposition occurs in the plating film even when the zinc plating bath additive described in the above-mentioned patent document is used. The abnormally deposited plating metal was easily detached from the member to be plated and became a foreign substance dispersed in the plating solution. If this foreign matter is properly collected by the filter member, there is no problem. However, if the foreign matter adheres to a portion where normal deposition of the member to be plated is to be performed before the foreign matter is collected, the attached foreign matter is taken into the plating film. As a result, the appearance of the plating film may be poor. The present invention has been made in view of such circumstances, and an object of the present invention is to increase the speed of formation of a galvanized film by a zincate-type galvanizing bath and to form a plated film at a high current density. Is to prevent the abnormal precipitation of.

In order to solve the above-mentioned problems, the additive production method of the present invention comprises: (D) at least one of dichloroalkyl ether, dichloroalkane and epichlorohydrin; (A) urea and ( B) N, N-dimethyl. Producing a zinc plating bath additive for zincate-type zinc plating bath by reacting ethylenediamine with (C) N, N, N ′, N′-tetraalkylalkylenediamine. It is characterized by.
Moreover, the additive manufacturing method of the present invention comprises (D) reacting at least one of dichloroalkyl ether, dichloroalkane and epichlorohydrin with (C) N, N, N ′, N′-tetraalkylalkylenediamine. And (A) urea and (B) N, N-dimethylethylenediamine are reacted with each other, and (D) at least one of dichloroalkyl ether, dichloroalkane and epichlorohydrin is reacted. Thus, a galvanizing bath additive for a zincate type galvanizing bath is manufactured.

In order to solve the above problems, the galvanizing bath additive of the present invention is characterized by containing a copolymer represented by the following structural formula (1).

In the formula, R ¹ = —CH ₂ CH ₂ —O—CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ —O—CH ₂ CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ CH ₂ —O— _{CH 2 CH 2 CH 2 CH 2} -, - CH 2 CH 2 CH 2 -, - CH 2 CH 2 CH 2 CH 2 -, - CH 2 CH (OH) CH 2 -
R ² , R ³ = CH ₃ —, CH ₃ CH ₂ —, CH ₃ CH ₂ CH ₂ —
R ⁴ = —CH ₂ CH ₂ —O—CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ —O—CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ CH ₂ —O—CH ₂ CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH (OH)
_{CH 2 Cl, -CH 2 CH (} OH) CH 2 OH, -CH 2 CHCH 2 O
^{R 5 = -N + (R 2} ) (R 3) (CH 2) n N (R 2) (R 3), - N + (CH 3) 2 (CH 2) 2 NHCONH (CH 2) 2 N ( _{CH 3) 2, -CH 2 CH} 2 -O-CH 2 CH 2 Cl, -CH 2 CH 2 CH 2 -O-CH 2 CH 2 CH 2 Cl, -CH 2 CH 2 CH 2 CH 2 -O-CH ₂ CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH (OH) CH ₂ Cl, —CH ₂ CH (OH) CH
₂ OH, —CH ₂ CHCH ₂ O
n = 1-8, X ≧ 1, Y ≧ 1, Z ≧ 1

  In order to solve the above-mentioned problems, the galvanizing bath of the present invention comprises 1 to 50 g / L of zinc, 30 to 250 g / L of sodium hydroxide, and 0.1 to 10 g / L (in terms of pure content). And a galvanizing bath additive.

  In order to solve the above-mentioned problems, the galvanized film forming method of the present invention comprises 1 to 50 g / L of zinc, 30 to 250 g / L of sodium hydroxide, and 0.1 to 10 g / L (pure component conversion). A galvanized film is formed using a galvanizing bath containing the above galvanizing bath additive.

(D) a reaction of at least one of dichloroalkyl ether, dichloroalkane and epichlorohydrin with (A) urea and (B) N, N-dimethylethylenediamine; and (C) N, N, N An additive produced by reacting ′, N′-tetraalkylalkylenediamine, or (D) at least one of dichloroalkyl ether, dichloroalkane and epichlorohydrin, and (C) N, N, N ', N'-tetraalkylalkylenediamine reacted, (A) urea and (B) N, N-dimethylethylenediamine reacted, (D) dichloroalkyl ether and dichloroalkane at least one additive which is prepared by reacting with epichlorohydrin, or represented by the structural formula (1) The additive promotes the formation of a galvanized film, and by adding the additive to a zincate-type galvanizing bath, the formation rate of the galvanized film can be increased. . In addition, by adding the additive to the galvanizing bath to form a galvanized film, it is possible to prevent abnormal deposition of the plated film at a high current density.

It is a figure which shows the composition structure of the sulfomethylethanediyl group and tetrathiomolybdenum in the (sulfomethylethanediyl) polythiomolybdate ion aqueous solution. It is a figure which shows the structure of molybdenum sulfide and a metal ion. It is a figure which shows the state which is disperse | distributing the soluble and stabilized nickel thioate complex by a sulfonic acid group in a nickel plating bath. It is a figure which shows the compounding quantity of the galvanization bath of Examples 1-5. It is a figure which shows the compounding quantity of the zinc plating bath of Comparative Examples 1-5. It is a figure which shows the result of the hull cell test using the zinc plating bath of Examples 1-3 and the zinc plating bath of Comparative Examples 1-3. It is a figure which shows the thickness of the plating film by the hull cell test using the zinc plating bath of Examples 1, 3-5, and the zinc plating bath of Comparative Examples 4 and 5. It is a figure which shows the external appearance of the plating film by the hull cell test using the zinc plating bath of Examples 1, 3-5, and the zinc plating bath of Comparative Examples 4 and 5. It is a figure which shows the compounding quantity of the nickel plating bath for forming the electroplating film of a zinc melt | dissolution acceleration | stimulation member, and an EDS analysis result. It is a figure which shows the result of the X-ray-diffraction measurement of the electroplating film | membrane of a zinc dissolution promotion member. It is the imaging photograph by the electron microscope of particles, such as nickel metal, nickel alloy, and molybdenum sulfide, which constitute a film. It is the imaging photograph by the electron microscope of particles, such as nickel metal, nickel alloy, and molybdenum sulfide, which constitute a film. It is a figure which shows the result of the dissolution test of zinc using the electroplating film of the zinc melt | dissolution acceleration | stimulation member, and another metal. It is a perspective view which shows a liquid circulation type plating tank apparatus. It is a figure which shows the relationship between working time and the zinc concentration in a plating bath.

  The “zinc plating bath additive” described in the present invention is represented by the above structural formula (1), and includes (A) urea, (B) N, N-dimethylethylenediamine, and (C) N, A copolymer of N, N ′, N′-tetraalkylalkylenediamine and (D) at least one of dichloroalkyl ether, dichloroalkane, and epichlorohydrin. Specifically, (A) urea and (B) N, N-dimethylethylenediamine are mixed and stirred at 60 to 180 ° C. for 1 to 20 hours. Thereby, N, N′-bis [2- (dimethylamino) ethyl] urea is obtained. Further, (C) N, N, N ′, N′-tetraalkylalkylenediamine, (D) at least one of dichloroalkyl ether, dichloroalkane, and epichlorohydrin are mixed with water, and 80 to 180 Stir at <RTIgt; C </ RTI> for 1-20 hours. As a result, a copolymer of (C) N, N, N ′, N′-tetraalkylalkylenediamine and (D) at least one of dichloroalkyl ether, dichloroalkane, and epichlorohydrin is obtained. Further, N, N′-bis [2- (dimethylamino) ethyl] urea, (D) at least one of dichloroalkyl ether, dichloroalkane, and epichlorohydrin and water are added to the copolymer. , And stir at 80 to 180 ° C. for 1 to 20 hours. And it cools to room temperature. Thereby, the “zinc plating bath additive” described in the present invention is produced. In addition, when epichlorohydrin is employ | adopted as a raw material of a galvanization bath additive, a ring-opening addition reaction arises.

  As another production method, (A) urea and (B) N, N-dimethylethylenediamine are mixed and stirred at 60 to 180 ° C. for 1 to 20 hours. Thereby, N, N′-bis [2- (dimethylamino) ethyl] urea is obtained. Further, (C) N, N, N ′, N′-tetraalkylalkylenediamine, (D) at least one of dichloroalkyl ether, dichloroalkane, and epichlorohydrin are mixed with water, and 80 to 180 Stir at <RTIgt; C </ RTI> for 1-20 hours. And it cools to room temperature. Thereby, the “zinc plating bath additive” described in the present invention is produced.

  N, N, N ′, N′-tetraalkylethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, N, N, N ′, N′-tetraethylethylenediamine, N, N, N ′, N'-tetrapropylethylenediamine and the like can be mentioned. Examples of the dichloroalkyl ether include dichloroethyl ether, dichloropropyl ether, dichlorobutyl ether and the like. Examples of the dichloroalkane include 1,3-dichloropropane and 1,4-dichlorobutane.

  The mixing ratio of the raw materials for the galvanizing bath additive, that is, (A) urea, (B) N, N-dimethylethylenediamine, (C) N, N, N ′, N′-tetraalkylalkylenediamine, (D) The compounding ratio (molar ratio) of dichloroalkyl ether, dichloroalkane and at least one of epichlorohydrin is 1.5 to 2.5: 3.5 to 4.5: 1.5 to 2. 5: 3.5 to 4.5 is preferable, and in particular, 1.7 to 2.3: 3.7 to 4.3: 1.7 to 2.3: 3.7 to 4.3. It is preferable. Furthermore, it is preferable that it is 1.9-2.1: 3.9-4.1: 1.9-2.1: 3.9-4.1.

  In addition, the “zinc plating bath additive” described in the present invention preferably has a weight average molecular weight (Mw) of 2000 to 50000 from the viewpoint of functional properties. Here, the functional characteristics are the characteristics that make the appearance of the zinc film good (prevention of galling of the zinc film, prevention of uneven glossy appearance), and the characteristics that quickly form the zinc film (increase the amount of zinc deposited per hour) Characteristic) and a characteristic (characteristic for forming a zinc film with a more uniform film thickness) that reduces the width of variation in film thickness at each location on the surface of the object. Moreover, it is more preferable that the weight average molecular weight of a water-soluble copolymer is 2000-30000 from a viewpoint of improving said functional characteristic more. This weight average molecular weight can be measured using a calibration curve of a cubic approximate curve using polyethylene oxide (PEO) as a standard sample.

  Moreover, the “zinc plating bath additive” described in the present invention has an action of suppressing excessive precipitation of zinc by containing a water-soluble copolymer containing the structural formula (1). By this action, it is possible to suppress an excessive amount of zinc from being deposited only at a part of the surface of the object, and as a result, it is possible to suppress a variation in the film thickness of the zinc film for each part of the surface of the object. .

  By adding the “zinc plating bath additive” described in the present invention to a zinc plating bath containing zinc and sodium hydroxide, the formation rate of the zinc plating film can be increased. The zinc concentration in the galvanizing bath to which the galvanizing bath additive is added is preferably 1 to 50 g / L, and particularly preferably 20 to 30 g / L. The concentration of sodium hydroxide in the galvanizing bath is preferably 30 to 250 g / L, and particularly preferably 140 to 200 g / L. The concentration of the additive in the galvanizing bath is preferably 0.1 to 10 g / L, and particularly preferably 0.8 to 5 g / L in terms of pure content. The pure conversion is a concentration converted based on the weight of the substrate, that is, the weight of the raw material of the additive. Moreover, since an additive is consumed by formation of a zinc plating film, it is necessary to supply an additive at the time of formation of a plating film so that the said density | concentration may be maintained.

  Moreover, since zinc is also consumed by the formation of the zinc plating film, it is necessary to supply zinc ions to the plating bath. In the “zinc plating bath” described in the present invention, a zinc dissolution accelerating member on which a specific electroplating film is formed is immersed in contact with zinc metal, and high-concentration zinc ions are supplied to the plating bath. Is done. This specific electroplating film is formed by using an acidic electroplating bath containing the “treatment solution” described in the present invention.

The treatment solution is produced by an addition reaction between an unsaturated hydrocarbon having a water-soluble functional group and a thioate. That is, a thioic acid derivative is produced by reacting a thionate with an alkyne compound or alkene compound having a water-soluble functional group. The thioacid derivative may be an S-ethanediyl group (—S—CH ₂ —CHR—S—) in which an ethylene group is bonded to a sulfur atom of thioacid, or an S-ethylenediyl group (—S—CH) in which an acetylene group is bonded. = CR-S-), and the water-soluble modifying group (R) has a sulfonate group, a carboxyl group, a polyether group, a hydroxyl group, a quaternary ammonium group, and the like. Furthermore, a compound having an alkene group or alkyne group that undergoes an addition bond reaction, or a compound having an epoxy group or glycidyl group that undergoes a ring-opening addition reaction can be used as a stabilizing modifier.

  Examples of the sulfonate functional group include allyl sulfonate, 2-methyl-2-propene-1-sulfonate, 3-butene-1-sulfonate, 4-pentene-1-sulfonate, and 5-hexene. -1-sulfonate, propargyl sulfonate, vinyl sulfonate, phenyl (meth) allyl ether sulfonate, 2-acrylamido-methylpropane sulfonate, etc., particularly sodium propargyl sulfonate, 2 -Sodium methyl-2-propene-1-sulfonate is preferred. Further, as the thioate, there are thiomolybdate, thiotungstate, thiocuprate, thiostannate, thioarsenic acid, thioantimonic acid, etc., thiomolybdate and thiotungstate are preferred, In particular, thiomolybdate is preferable. Furthermore, intramolecular cyclic sulfonates that undergo a ring-opening addition reaction can also be used as stabilizing modifiers. In particular, propane sultone is preferable.

  The mixing molar ratio of the unsaturated hydrocarbon having a water-soluble functional group and the thioate salt may be 1:20 to 20: 1, and particularly preferably 1: 5 to 5: 1.

By adding metal ions to the treatment solution, it is possible to adjust a black colloid solution with high dispersion solubility. For example, a treatment solution generated by an addition reaction of an unsaturated hydrocarbon having a sulfonate functional group and a thiomolybdate, that is, a sulfomethylethanediyl group (—CH ₂ —CH (CH ₂ SO ₃ H —) —) By adding a metal ion (Co, Cu, Ni, Pd, Rh, Ru, etc.) to a water-soluble (sulfomethylethanediyl) polythiomolybdate ion aqueous solution having a metal ion and high hydrophilicity ( Sulfomethylethanediyl) Dispersible black colloid solution having water-soluble molybdenum / metal composite sulfide ion (alkylsulfonate ion and sulfide ion) having a structure in which at least part of polythiomolybdate ion is bonded Is adjusted.

Specifically, the sulfomethylethanediyl group (—CH ₂ —CH (CH ₂ SO ₃ H —) —) in the (sulfomethylethanediyl) polythiomolybdate ion aqueous solution is, as shown in FIG. It is thought that it is couple | bonded in the ratio of 1-2 per thiomolybdenum dimer. Due to this structure, it is considered that the metal ions added to the (sulfomethylethanediyl) polythiomolybdate ion aqueous solution are stably dispersed. That is, by adding metal ions to the (sulfomethylethanediyl) polythiomolybdate ion aqueous solution, as shown in FIG. 2, nano-sized molybdenum sulfide and metal ions are coordinated to form the state shown in FIG. It is thought that it is dispersed in the solution.

  Thus, by adding metal ions to the treatment solution, a highly colloidally dispersed black colloid solution is prepared, and this solution can be used as an electroplating bath. The plating bath may be a nickel plating bath, a copper plating bath, a cobalt plating bath, or more specifically a plating bath containing a metal such as Mn, Fe, Sn, Pd, Ru, Rh, depending on the type of metal ions to be added. Can be adjusted.

  The concentration of the thioic acid derivative produced by the addition reaction of the unsaturated hydrocarbon and the thioate in the electroplating bath containing the treatment solution is preferably 0.001 to 10% by mass, particularly preferably It is preferable that it is 01-1 mass%.

  The pH of the electroplating bath containing the treatment solution is preferably 1.0 to 6.0, and particularly preferably 2.0 to 4.0. Moreover, it is preferable that bath temperature is 20-80 degreeC, and it is especially preferable that it is 40-60 degreeC.

  In the electroplating bath containing the above treatment solution, as a compound that imparts conductivity and buffering properties, inorganic acids, organic acids, their alkali salts, organic complexing agents, their alkali salts, organic amines, organic compounds Polyamines and the like may be included.

  The electroplating bath containing the treatment solution further includes a film stabilizer, a film adhesion enhancer, a compound having a phenolic hydroxyl group, a low-molecular compound such as a phenolic acid salt, a polymer compound having them as a skeleton, tannin, High molecular compounds called polyphenols such as tannic acid and catechin may be included.

In the electroplating bath containing the treatment solution, it is preferable to employ an electrolysis method in which anodic electrolysis and cathodic electrolysis are alternately repeated, a so-called PR electrolysis method. Thereby, it is possible to form a film in which a metal and molybdenum sulfide are appropriately combined. Note that when employing the PR electrolytic method, the current density during cathodic electrolysis and 0.1~20A / dm ^2, the current density during the anodic electrolysis is preferably to 0.1~20A / dm ^2, especially the current density during cathodic electrolysis and 1-5A / dm ^2, the current density during the anodic electrolysis is preferably a 1-5A / dm ^2. The cathode electrolysis time is preferably 0.1 to 10 seconds and the anodic electrolysis time is preferably 0.1 to 5 seconds. The ratio of the cathode electrolysis time to the anodic electrolysis time is as follows: cathodic electrolysis time: anodic electrolysis time = The ratio is preferably 1: 0.1 to 1: 1.

  Further, when a soluble anode or an insoluble anode is used for a long period of time, it is preferable to use a membrane separation electrode, a hydrogen diffusion electrode, or the like.

Moreover, it is preferable to perform strike plating before forming a film with an electroplating bath containing the treatment solution. Thereby, it is possible to appropriately form a film by an electroplating bath containing the treatment solution and to increase the adhesion. In addition, it is preferable that the cathode current density at the time of strike plating processing is 2-20 A / dm < ² >, and it is especially preferable that it is 5-15 A / dm < ² >. The bath temperature is preferably 15 to 35 ° C.

  By using an electroplating bath containing the treatment solution, a film having a high molybdenum content can be formed. Specifically, for example, the molybdenum content in the film can be 10 to 30% by weight, and when converted to molybdenum disulfide, a film of 15 to 50% by weight can be formed. .

  The film formed using the electroplating bath containing the above treatment solution can be adjusted by adding metal ions, etc., so that Ni, Cu, Co, Mn, Fe, In, Ir, Pt, Sn, Pd, Ag , Ru, Rh, or a single metal, or an alloy of two or more elements thereof, or a multi-component alloy including Mo, W, etc. that undergoes induction eutectoid. Further, the coating includes metal oxides such as Mo, W, Zr, Si, Ce, V, Al, Ni, Cu, Co, Mn, Fe, In, Sn, Pd, Ag, Ru, and Rh, sulfides, and the like. Fine particles, carbon nanotubes, carbon nanofibers, carbon bodies such as carbon black, alkali metal compound ions, alkaline earth metal compounds, and the like.

  Moreover, it is preferable to coat the film formed using an electroplating bath containing the treatment solution with titanium. The titanium coating improves alkali durability and improves durability when immersed in a galvanizing bath. In addition, the formation method of a titanium coating is not limited, Adopting various methods, such as the formation method of the titanium coating by the immersion to the processing liquid containing titanium, the formation method of the titanium coating using plasma Is possible.

  The elemental composition of the coating formed when a nickel plating bath is used as the electroplating bath containing the treatment solution and the titanium coating applied on the coating was analyzed using an analytical scanning electron microscope (JSM-6480A JEOL). EDS analysis by the company), Ni: 20-95 mass%, Mo: 0.1-25 mass%, S: 0.1-40 mass%, O: 0-40 mass%, C: 0 It is preferable that they are 40 mass% and Ti: 0-15 mass%. Further, the diameter of at least one fine particle of nickel metal and nickel alloy and the fine particle of molybdenum sulfide contained in the film formed when the nickel plating bath is used is preferably 50 nm or less, and particularly 30 nm or less. It is preferable that

  The following examples illustrate the present invention more specifically. However, the present invention is not limited to this embodiment, and can be implemented in various modes with various modifications and improvements based on the knowledge of those skilled in the art.

The galvanizing baths of Examples 1 to 5 and the galvanizing baths of Comparative Examples 1 to 5 were prepared from the raw materials having the formulations shown in FIGS. 4 and 5. Additive 1 is composed of (A) urea, (B) N, N-dimethylethylenediamine, (C) N, N, N ′, N′-tetramethylethylenediamine, and (D) dichloroethyl ether. Synthesized. Specifically, (A) 2 mol of urea and (B) 4 mol of N, N-dimethylethylenediamine are mixed and stirred at 100 ° C. for 5 to 10 hours. Thereby, 2 mol of N, N′-bis [2- (dimethylamino) ethyl] urea is obtained. Further, (C) 2 mol of N, N, N ′, N′-tetramethylethylenediamine, 4 mol of (D) dichloroethyl ether, and an arbitrary amount of water are mixed and stirred at 100 ° C. for 5 to 10 hours. And it cools to room temperature. Thereby, additive 1 is obtained. In addition, the structural formula of the additive 1 is the above structural formula (1) (R ¹ = —CH ₂ CH ₂ —O—CH ₂ CH ₂ —, R ² , R ³ = CH ₃ —, R ⁴ = —CH _{2. ^{CH 2 -O-CH 2 CH 2}} Cl, R 5 = -CH 2 CH 2 -O-CH 2 CH 2 Cl, -N + (R 2) (R 3) (CH 2) n n (R 2) ( _{^{R 3), - n + (}} CH 3) 2 (CH 2) 2 NHCONH (CH 2) 2 n (CH 3) 2, n = 2) it is.

Additive 2 includes (A) urea, (B) N, N-dimethylethylenediamine, (C) N, N, N ′, N′-tetraethylethylenediamine, and (D) 1,3-dichloropropane. And synthesized. Specifically, (A) 2 mol of urea and (B) 4 mol of N, N-dimethylethylenediamine are mixed and stirred at 100 ° C. for 5 to 10 hours. Thereby, 2 mol of N, N′-bis [2- (dimethylamino) ethyl] urea is obtained. Furthermore, (C) N, N, N ′, N′-tetraethylethylenediamine (2 mol), (D) 1,3-dichloropropane (4 mol) and an arbitrary amount of water are mixed and stirred at 100 ° C. for 5 to 10 hours. To do. And it cools to room temperature. Thereby, the additive 2 is obtained. In addition, the structural formula of the additive 2 is the above structural formula (1) (R ¹ = —CH ₂ CH ₂ CH ₂ —, R ² , R ³ = CH ₃ CH ₂ —, R ⁴ = —CH ₂ CH ₂ CH _{^{2 Cl, R 5 = -CH 2}} CH 2 CH 2 Cl, -N + (R 2) (R 3) (CH 2) n n (R 2) (R 3), - n + (CH 3) 2 ( CH ₂₎ a _{2 NHCONH (CH 2) 2 n} (CH 3) 2, n = 2).

For Additives 1 and 2, the molecular weight was measured using a high-speed GPC device, HLC-8320GPC, Eco SEC (manufactured by Tosoh Corp.) and a calibration curve of a cubic approximation curve using polyethylene oxide (PEO) as a standard sample. (GPC measurement conditions are as follows). As a result, it was found that additive 1 had an Mw of 7800 and additive 2 had an Mw of 6700. GPC is a method of separating a target substance by molecular size. A GPC apparatus is an apparatus that separates substances by using a chromatograph using a column that can be sorted according to the size of molecules. GPC is particularly excellent in the separation and analysis of polymer substances. Aqueous GPC is a kind of size exclusion chromatography and is also called abbreviated SEC.
<GPC measurement common conditions>
Water-based GPC equipment: HLC-8320GPC, EcoSEC (manufactured by Tosoh Technosystem Co., Ltd.)
Column: TSKgel G6000PWXL-CP + TSKgel G3000PWXL-CP (7.8 mm ID X 30 cm)
Detector: Differential refractometer (RI detector)
Eluent: 0.1M NaNO3 aqueous solution Column temperature: 40 ° C

  In addition, additive 4 contains 1 mol of N- [2- (dimethylamino) ethyl] urea, 1 mol of N, N′-bis [2- (dimethylamino) ethyl] urea, 1 mol of epichlorohydrin, and dichloroethyl. 1 mol of ether and an arbitrary amount of water are mixed and stirred at 100 ° C. for 5 to 10 hours. And it cools to room temperature. Thereby, the additive 4 is obtained. Additive 3 is WT manufactured by MIRAPOL.

A Hull cell test was performed using the adjusted galvanizing baths of Examples 1 to 5 and Comparative Examples 1 to 5. The conditions of the Hull cell test are as follows.
Current: 4A
Time: 5 minutes Temperature: 25 ° C
Stirring: None

  FIG. 6 shows the results of the zinc plating baths of Examples 1 to 3 and the zinc plating baths of Comparative Examples 1 to 3 in the Hull cell test. As can be seen from the figure, when the zinc concentration and the sodium hydroxide concentration are the same, the thickness of the galvanized film formed in the zinc plating bath to which additive 1 is added is added by additive 3 The thickness of the galvanized film formed in the galvanized bath is about 1.25 to 1.5 times or more. Specifically, in the zinc plating bath (zinc plating bath of Example 1 and zinc plating bath of Comparative Example 1) having a zinc concentration of 10 g / L and a sodium hydroxide concentration of 120 g / L, additive 1 is added. In this case, the thickness of the galvanized film is about 1.25 times the thickness of the galvanized film when the additive 3 is added. In addition, in a zinc plating bath (zinc plating bath of Example 2 and zinc plating bath of Comparative Example 2) having a zinc concentration of 15 g / L and a sodium hydroxide concentration of 150 g / L, additive 1 is added The thickness of the galvanized film is about 1.35 times the thickness of the galvanized film when the additive 3 is added. In addition, in a zinc plating bath (zinc plating bath of Example 3 and zinc plating bath of Comparative Example 3) having a zinc concentration of 20 g / L and a sodium hydroxide concentration of 160 g / L, additive 1 is added The thickness of the galvanized film is about 1.5 times or more the thickness of the galvanized film when the additive 3 is added. From this, it is understood that a zinc plating film can be formed at a high speed by adding the additive 1 represented by the structural formula (1) to a zincate type zinc plating bath.

  Moreover, the result of the zinc plating bath of Examples 1 and 3-5 of the above-mentioned Hull cell test and the zinc plating bath of Comparative Examples 4 and 5 is shown in FIG. As can be seen from the figure, in the zinc plating baths having a zinc concentration of 20 g / L and a sodium hydroxide concentration of 160 g / L (the zinc plating baths of Examples 3 and 5 and the zinc plating bath of Comparative Example 5), the additive The thickness of the galvanized film when 1 is added is about 1.3 times the thickness of the galvanized film when Additive 4 is added. However, the thickness of the galvanized film when the additive 2 is added is approximately the same as the thickness of the galvanized film when the additive 4 is added. Moreover, in the zinc plating bath (zinc plating bath of Examples 1 and 4 and the zinc plating bath of Comparative Example 4) having a zinc concentration of 10 g / L and a sodium hydroxide concentration of 120 g / L, When the distance is long, the thickness of the galvanized film when the additive 1 or the additive 2 is added is larger than the thickness of the galvanized film when the additive 4 is added. When the distance from the edge is short, the thickness of the galvanized film when additive 1 or additive 2 is added is thinner than the thickness of the galvanized film when additive 4 is added. That is, by adding the additive 4 to the galvanizing bath, it becomes possible to form a galvanized film at a high speed as much as when the additive 1 or the additive 2 is added to the galvanizing bath.

Moreover, the hull cell test was done using the adjusted zinc plating baths of Examples 1 and 3 to 5 and the zinc plating baths of Comparative Examples 4 and 5, and the appearance of the plating film was evaluated. The conditions of the Hull cell test are as follows.
Current: 4A
Time: 5 minutes Temperature: 25 ° C
Stirring: None Adjustment of plating area: In order to increase the current density, the plating area of the anode iron plate was set to 1/5 that of a normal hull cell. Specifically, the upper 2 cm portion and the lower 2 cm portion of the longitudinal length (5 cm) of the anode iron plate were masked to expose only the central 1 cm portion of the anode iron plate. .

The external appearance of the plating film formed in the said hull cell test is shown in FIG. The dark colored portion in the figure indicates a glossy appropriate plating film, and the white portion in the figure indicates a dull plating film. As can be seen from the figure, the plating film formed in the zinc plating baths of Examples 1 and 3 to 5, that is, the zinc plating bath to which the additive 1 or the additive 2 was added had no abnormal precipitation, and was plated. The appearance is uniform gloss. On the other hand, the plating film formed by the zinc plating baths of Comparative Examples 4 and 5, that is, the zinc plating bath to which the additive 4 was added had no abnormal precipitation at a current density of about 30 A / dm ² or less. The appearance is uniform gloss. However, there is abnormal precipitation at a high current density of about 30 A / dm ² or more, and the appearance of plating is not glossy. From this, it can be understood that abnormal precipitation at a high current density can be prevented by adding the additive 1 or the additive 2 represented by the structural formula (1) to the galvanizing bath.

Further, a nickel plating bath was prepared from each raw material having the composition shown in FIG. 9, and a plating film was formed on the iron piece (surface area: 0.1 dm ² ) using the nickel plating bath. Below, the toning method of a nickel plating bath and the formation method of a plating film are demonstrated in detail.

  First, a raw material molybdate derivative aqueous solution is produced by ammonium tetrathiomolybdate and sodium 2-propyne-1-sulfonate. Ammonium tetrathiomolybdate is produced by the following method. 200 ml of water is added to 400 ml of concentrated ammonia water to dissolve 71 g of ammonium heptamolybdate. And after heating to 60-70 degreeC, 500 ml of 22% ammonium sulfide is added. This produces ammonium tetrathiomolybdate. 3 g (11.53 mmol) of ammonium tetrathiomolybdate thus produced is dissolved in 1000 ml of water. Then, 8.19 ml (11.53 mmol) of a 20% aqueous solution of sodium 2-propyne-1-sulfonate is added and stirred for 1 hour. Then, it is left to react at a constant temperature of 50 ° C. for 8 hours. Thereby, a molybdate derivative aqueous solution is generated.

  Next, 120 g of nickel sulfate and 30 g of boric acid are completely dissolved in 500 ml of the molybdate derivative aqueous solution produced by the above method, and diluted with water to prepare a 1 L nickel plating bath. The pH of the nickel plating bath is adjusted to pH 2 with dilute sulfuric acid or sodium hydroxide.

Further, before the formation of the plating film by the nickel plating bath, nickel strike is performed on the iron piece according to the following conditions in order to improve the adhesion of the film. Note that nickel or an insoluble anode is used as the counter electrode.
Nickel chloride 6H ₂ O: 250 g / L
White hydrochloric acid: 120cc / L
pH: 1 or less Cathode current density: 10 A / dm ²
Bath temperature: 25 ° C

When nickel strike is performed under the above conditions, PR electrolysis is performed using the nickel plating bath. The conditions for the electrolysis of the PR electrolysis method are as follows.
Current density during cathode electrolysis: 1 A / dm ²
Current density during anodic electrolysis: 0.5 A / dm ²
Cathodic electrolysis time: 5 seconds Anode electrolysis time: 5 seconds Stirring: None Bath temperature: 50 ° C
Counter electrode: nickel or insoluble anode The electroplating is performed in a state where the counter electrode is separated by a diaphragm.

  A film is formed on the surface of the iron piece by performing electrolysis of PR electrolysis under the above conditions. X-ray diffraction measurement was performed on this film, and the measurement results are shown in FIG. As can be seen from the figure, a gentle peak exists in the range of about 30 to 40 (deg), and it can be seen that microcrystalline molybdenum disulfide is contained in the film. Moreover, a peak exists at about 45 (deg), and it turns out that nickel of a microcrystal is contained in the film. The X-ray diffraction was measured using a fully automatic horizontal multipurpose X-ray diffractometer (SmartLab Rigaku).

  Moreover, the film formed on the surface of the iron piece was photographed with an electron microscope, and the particle diameters of nickel metal, nickel alloy, molybdenum sulfide, etc. constituting the film were measured. As a result of the measurement, the particle diameters of nickel metal, nickel alloy, molybdenum sulfide and the like were several nm to 50 nm as shown in FIGS. In addition, the electron microscope used for imaging | photography is the reaction science ultrahigh voltage | pressure scanning transmission electron microscope (JIM-1000K RS JEOL Co., Ltd. product).

  From the above results, a composite film of nickel and molybdenum sulfide is formed on the surface of the iron piece, and the composite film is composed of nanometer-sized dense particles with uniform particle diameters. I understand that

  Further, a titanium coating is applied to the surface of the composite film. Specifically, 100 g of water was added to 7.8 g of a titanium chloride (iv) aqueous solution (16.5% by mass, manufactured by Wako Pure Chemical Industries, Ltd.), and ammonia water (25% by mass, Wako Pure Chemical Industries, Ltd.). )) To adjust the pH to 4-5. Thereby, titanium hydroxide precipitates. The precipitated titanium hydroxide is washed several times with water and less than 1 L of water is added to the washed titanium hydroxide. Then, while heating the aqueous solution to 40 ° C., 25.35 g of hydrogen peroxide (30% by mass, manufactured by Wako Pure Chemical Industries, Ltd.) is added. Furthermore, the aqueous solution is made 1 L by adding water. While stirring at 40 ° C., the mixture is stirred for 8 hours to dissolve the precipitate. Further, by heating at 90 ° C. for 3 hours, a yellow translucent titanium coating treatment liquid is prepared.

  The iron piece on which the film is formed is immersed in the adjusted titanium coating treatment solution for 10 seconds. And a titanium coating is formed in the surface of a membrane | film | coat by heating at 80 degreeC. In addition, in order to improve the adhesiveness of a membrane | film | coat and a titanium coating, heat processing are performed at 250 degreeC for 2 hours.

  In accordance with the above method, there is a member in which a composite film of nickel and molybdenum sulfide is formed on the surface of the iron piece, and a titanium coating is applied to the surface of the composite film (hereinafter sometimes referred to as a zinc dissolution promoting member). It is formed. In order to analyze the elemental composition of the composite film and titanium coating of the zinc dissolution promoting member, EDS analysis was performed. The result is shown in the “EDS analysis” column of FIG.

  From the result of EDS analysis, it is understood that the composite film of the zinc dissolution promoting member contains about 5% by mass of molybdenum sulfide fine particles. Using this zinc dissolution accelerating member having a composite film containing about 5% by mass of molybdenum sulfide fine particles (hereinafter sometimes referred to as a 5% by mass Mo-containing member), zinc in a galvanizing bath is used. The amount of dissolution was measured.

Specifically, a state in which a 5 mass% Mo-containing member and a zinc metal plate (surface area: 0.25 dm ² ) are brought into contact with a zinc plating bath having a zinc concentration of 10 g / L and a sodium hydroxide concentration of 120 g / L. The zinc concentration after 24 hours and the zinc concentration after 72 hours were measured. Then, by subtracting the initial zinc concentration (10 g / L) from the zinc concentration after 24 hours and the zinc concentration after 72 hours, the amount of zinc increase, that is, the amount of zinc dissolved (g / L), is reduced. It was measured. As a comparative example, instead of a 5 mass% Mo-containing member, iron, iron casting, nickel plating (a normal nickel plating is applied to the metal surface), or a Pt / Ti alloy is used as a comparative example. The amount of zinc dissolved (g / L) when immersed in a galvanizing bath in a state where the respective metals were brought into contact with the zinc metal plate was also measured. Further, the amount of zinc dissolved (g / L) was measured when only the zinc metal plate was immersed in the zinc plating bath without bringing the metal into contact with the zinc metal plate. Furthermore, in order to clarify the relationship between the composite film of nickel and molybdenum sulfide and the amount of zinc dissolved, a zinc dissolution promoting member (hereinafter referred to as 10 mass) having a composite film containing about 10% by mass of molybdenum sulfide fine particles. The amount of zinc dissolved (g / L) when immersed in a galvanizing bath in a state where the zinc metal plate is in contact with the zinc metal plate may be measured. The method for producing the 10% by mass Mo-containing member is substantially the same as the method for producing the 5% by mass Mo-containing member, and the current density during cathodic and anodic electrolysis, cathodic electrolysis time, anodic electrolysis time, etc. are adjusted. Thus, a 10% by mass Mo-containing member is formed. The zinc concentration was measured using an ICP emission spectroscopic analyzer (manufactured by SPS 5520 SII Nano Technology Co., Ltd.).

  The amount of zinc dissolved (g / L) is shown in FIG. The melting efficiency in the figure is based on the amount of zinc dissolved when immersed in a galvanizing bath in a state where iron and a zinc metal plate are in contact with each other, and a predetermined metal and a zinc metal plate are in contact with each other. The ratio of the dissolved amount of zinc when immersed in a zinc plating bath to the reference dissolved amount. That is, the higher the dissolution efficiency, the more zinc dissolves in the galvanizing bath.

  As can be seen, the zinc does not dissolve in the galvanizing bath when no metal is in contact with the zinc. However, when iron is brought into contact with zinc, zinc is dissolved in the zinc plating bath to some extent. Further, by bringing the iron casting or nickel plating into contact with zinc, the melting efficiency is about 2, and the amount of zinc dissolved is slightly increased. Furthermore, by bringing the Pt / Ti alloy into contact with zinc, the melting efficiency becomes 27.5, and the amount of zinc dissolved increases dramatically. However, Pt / Ti alloys are not practical because they are very expensive.

  On the other hand, the 5 mass% Mo-containing member and the 10 mass% Mo-containing member are not so expensive, and by contacting the 5 mass% Mo-containing member or the 10 mass% Mo-containing member with zinc, iron, iron Compared with castings and nickel plating, the amount of zinc dissolved increases. In particular, when a 10% by mass Mo-containing member is brought into contact with zinc, the dissolution efficiency is 38.5, and more zinc is dissolved in the plating bath than when an expensive Pt / Ti alloy is brought into contact with zinc. To do. From this, a large amount of zinc dissolution accelerating member, that is, by immersing in a zinc plating bath in a state where zinc is in contact with a composite coating formed by an electroplating bath containing a molybdate derivative aqueous solution, a large amount of It can be seen that zinc dissolves in the plating bath.

  From the above results, the formation rate of the galvanized film was immersed in a zinc plating bath to which the additive represented by the structural formula (1) was added while the zinc dissolution accelerating member and zinc were brought into contact with each other. It can be seen that the formation speed can be maintained at a high speed. Specifically, according to the galvanizing bath to which the additive represented by the structural formula (1) is added, a galvanized film is formed at a high speed. On the other hand, when the galvanized film is formed at a high speed, the consumption rate of zinc ions is also increased. Therefore, unless the zinc ions are supplied to the galvanizing bath at a high speed, the formation speed of the plated film is lowered. Therefore, by immersing the zinc dissolution promoting member and zinc in contact with the zinc plating bath, a large amount of zinc is dissolved in the plating bath, and zinc ions are supplied to the zinc plating bath at a high speed. Thus, the formation rate of the galvanized film is increased by immersing the zinc dissolution accelerating member and zinc in contact with the zinc plating bath to which the additive represented by the structural formula (1) is added. And the increased formation speed can be maintained.

Next, the following test was conducted in order to evaluate the time during which zinc ions can be supplied when the zinc dissolution accelerating member and zinc are brought into contact with each other in a zinc plating bath. For the test, a liquid circulation type plating apparatus (Smart Cell For SMI, manufactured by Yamamoto Gold Tester) 10 shown in FIG. 14 was used. The plating apparatus 10 includes a liquid tank 12, and the inside of the liquid tank 12 is divided into a plating electrolytic tank 16 and a zinc dissolution tank 18 by a partition plate 14. The capacity of the plating electrolysis tank 16 is 0.8 L, and when a plating solution with a capacity larger than that is put into the plating electrolysis tank 16, the plating solution with a capacity exceeding 0.8 L flows into the zinc dissolution tank 18. . In this test, 1 L of zinc plating solution is placed in the liquid tank 12, 0.8 L of zinc plating liquid enters the plating electrolysis tank 16, and 0.2 L of zinc plating liquid flows into the zinc dissolution tank 18. To do. The composition of the galvanizing solution used in this test is as follows.
Zinc: 30g / L
Sodium hydroxide: 160 g / L
Additive 1: 1 Automatic supply so that it becomes 1g / L (pure component conversion)

An iron basket 20 is immersed in the zinc dissolution tank 18. The basket 20 is formed with the above-described composite film and functions as a zinc dissolution promoting member. That is, a composite film of nickel and molybdenum disulfide is formed on the surface of the basket 20 using a nickel plating bath containing the aqueous molybdate derivative solution. A zinc metal plate (surface area: 0.5 dm ² ) 22 is accommodated in the basket 20. As a result, the composite coating of nickel and molybdenum disulfide, that is, the zinc dissolution accelerating member and the zinc metal plate 22 are immersed in the plating bath.

  Further, the plating apparatus 10 is formed with a passage 24 connecting the plating electrolytic bath 16 and the zinc dissolution bath 18, and driving for sending the plating solution from the zinc dissolution bath 18 to the plating electrolytic bath 16 in the passage 24. A source (not shown) is provided. Thereby, in the plating apparatus 10, zinc is dissolved in the plating solution in the zinc dissolving tank 18, and the plating solution in which the zinc is dissolved is sent out to the plating electrolytic tank 16. Then, the plating solution having a reduced zinc concentration flows from the plating electrolysis tank 16 into the zinc dissolution tank 18 beyond the partition plate 14. As described above, in the plating apparatus 10, the plating solution is constantly circulated between the plating electrolytic bath 16 and the zinc dissolution bath 18.

  Using such a liquid circulation type plating apparatus 10, the zinc concentration in the plating electrolysis tank 16 when the plating process was performed for a long time was measured, and the appearance of the plating was observed. The measurement of the zinc concentration and the appearance observation of the plating were performed 24 hours, 100 hours, 200 hours, 400 hours, and 800 hours after the start of the plating treatment. The result is shown in FIG. As can be seen from the figure, the zinc concentration is generally maintained at the initial concentration (30 g / L) at all times even when the plating process is performed for 800 hours. Moreover, even if it is a case where a plating process is performed continuously for 800 hours, it turns out that the external appearance of plating is always a uniform luster. From this, it is understood that an appropriate amount of zinc can be dissolved in the plating bath continuously for 800 hours or more by immersing in the zinc plating bath in a state where the zinc dissolution accelerating member is in contact with zinc. Further, it can be seen that a high-quality galvanized film can be formed at a high speed for 800 hours or more.

Claims (7)

(D) at least one of dichloroalkyl ether, dichloroalkane and epichlorohydrin;
(A) urea and (B) N, N-dimethylethylenediamine reacted ;
(C) N, N, N ′, N′-tetraalkylalkylenediamine ;
By reacting, added pressure agent manufacturing method you characterized by producing zinc plating bath additives zincate type galvanizing bath. (D) a reaction of at least one of dichloroalkyl ether, dichloroalkane and epichlorohydrin with (C) N, N, N ′, N′-tetraalkylalkylenediamine;
(A) urea and (B) N, N-dimethylethylenediamine reacted ;
( D) at least one of dichloroalkyl ether, dichloroalkane and epichlorohydrin ;
By reacting, added pressure agent manufacturing method you characterized by producing zinc plating bath additives zincate type galvanizing bath. (D) at least one of dichloroalkyl ether, dichloroalkane and epichlorohydrin, (A) urea, (B) N, N-dimethylethylenediamine, and (C) N, N, N ′, N′— The molar ratio of the tetraalkylalkylenediamine is 3.5 to 4.5: 1.5 to 2.5: 3.5 to 4.5: 1.5 to 2. Additives The process according to claim 1 or claim 2, characterized in that 5 a.   1-50 g / L of zinc;
  30-250 g / L sodium hydroxide;
  A 0.1-10 g / L (in terms of pure content) zinc plating bath additive produced by the additive production method according to any one of claims 1 to 3, and
  A method for forming a galvanized film, comprising forming a galvanized film using a galvanizing bath containing A zinc plating bath additive for a zincate-type zinc plating bath, comprising a copolymer represented by the following structural formula (1).

In the formula, R ¹ = —CH ₂ CH ₂ —O—CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ —O—CH ₂ CH ₂ CH ₂ —, —CH ₂ CH ₂ CH ₂ CH ₂ —O— _{CH 2 CH 2 CH 2 CH 2} -, - CH 2 CH 2 CH 2 -, - CH 2 CH 2 CH 2 CH 2 -, - CH 2 CH (OH) CH 2 -
R ² , R ³ = CH ₃ —, CH ₃ CH ₂ —, CH ₃ CH ₂ CH ₂ —
R ⁴ = —CH ₂ CH ₂ —O—CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ —O—CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ CH ₂ —O—CH ₂ CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH (OH)
_{CH 2 Cl, -CH 2 CH (} OH) CH 2 OH, -CH 2 CHCH 2 O
^{R 5 = -N + (R 2} ) (R 3) (CH 2) n N (R 2) (R 3), - N + (CH 3) 2 (CH 2) 2 NHCONH (CH 2) 2 N ( _{CH 3) 2, -CH 2 CH} 2 -O-CH 2 CH 2 Cl, -CH 2 CH 2 CH 2 -O-CH 2 CH 2 CH 2 Cl, -CH 2 CH 2 CH 2 CH 2 -O-CH ₂ CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH ₂ CH ₂ CH ₂ Cl, —CH ₂ CH (OH) CH ₂ Cl, —CH ₂ CH (OH) CH
₂ OH, —CH ₂ CHCH ₂ O
n = 1-8, X ≧ 1, Y ≧ 1, Z ≧ 1 1-50 g / L of zinc;
30-250 g / L sodium hydroxide;
A galvanizing bath comprising the galvanizing bath additive according to claim 5 at 0.1 to 10 g / L (in terms of pure content). 1-50 g / L of zinc;
30-250 g / L sodium hydroxide;
A method of forming a galvanized film, comprising forming a galvanized film using a galvanized bath containing 0.1 to 10 g / L (in terms of pure content) of the galvanized bath additive according to claim 5. .