JPH02277794A - Organic solvent electroplating solution for plating film of r2t14b intermetallic compound permanent magnet - Google Patents

Abstract

PURPOSE:To form an oxidation-resistant coating film with the glossiness and adhesion improved by incorporating specified boric acid compd., alkali metal and tetraalkylammonium salt to the org. solvent electroplating soln. for a plating film as the supporting salt. CONSTITUTION:A plating film is formed with the org. solvent electroplating soln. on the surface of an R2T14B intermetallic compd. permanent magnet material (R is the rare-earth elements including Y, and T is transition metals). At least one kind among the boric acid compd. contg. >=1 kind among R'3BO3, MBO2, M'BO3 and M'2BxO (R' is H or an alkyl group, M is H or an alkali metal, M' is an alkali metal and x>=2), an alkali metal contg. either M'XO4 (X is a halogen) or R'4NXO4 or the XO4<-> salt of a tetraalkylamine, the BX4<-> salt (or PX6<-> salt) of an alkali metal and a tetraalkylamine and the R'COO<-> salt of an alkali metal is added to the plating soln. as the supporting salt.

Description

[Detailed description of the invention] [Industrial field of application]
Regarding the improvement of oxidation resistance of 2T14B intermetallic compound permanent magnets (here, R is a rare earth element including Y, and T is a transition metal), in particular, forming a plating film that coats R2T14B intermetallic compound permanent magnets. The present invention relates to an organic solvent electrolytic plating solution for use in organic solvent electrolytic plating.

[Prior art] In general, R2T,4 represented by Nd-Fe-B magnets
B rare earth permanent magnets are known to have superior magnetic properties compared to Sm--Co rare earth permanent magnets. In addition, in terms of price, since Nd and Fe, which are abundant in resources, are the main components, it has the advantage that it can be supplied at a lower price than the Sm-Co type, and its range of use is expanding.

However, on the other hand, R-Fe-B rare earth permanent magnets contain a special internal oxidation factor in that the metal structure of their alloy contains an R-Fe solid solution phase that is extremely susceptible to oxidation in the atmosphere. As a result, an oxide film is deposited and formed on the magnet surface, causing deterioration and variation in magnetic properties.
When used as a component for a magnetic circuit or the like, there is a problem in that the oxide film scatters and causes contamination of peripheral equipment.

Therefore, conventionally, as described in JP-A-80-54406 or JP-A-60-83903, an oxidation-resistant coating such as plating or chemical conversion coating was applied to the surface of the magnet using an aqueous plating solution. A method of forming was adopted.

[Target to be Solved by the Invention] However, in the conventional methods of forming oxidation-resistant films such as plating and chemical conversion films described above, a large amount of water or aqueous solution is used in the plating solution used in the plating process. Since it has a specific oxidation factor, it has the disadvantage that the R-Fe solid solution phase is preferentially oxidized during the treatment process. As a result, the important pretreatment effect in the plating process is lost,
The formation and growth of the plating film on the surface of the magnet is hindered,
Problems arise such as poor adhesion and powdery electrodeposit.

Furthermore, even if it is possible to form an oxidation-resistant film such as a plating film or a chemical wave film on the surface of the magnet, the oxide film existing between the surface of the magnet and the film may remain in the film. Internal oxidation progresses due to adsorbed water molecules, etc., resulting in defects on the adhesion side such as blistering of the film and peeling of the film.

Furthermore, even in a surface treatment method using a PVD method such as ion blasting, the film structure becomes a resin-like precipitation and lacks density.

That is, with these conventional surface treatment methods, it is difficult to improve corrosion resistance.

On the other hand, as described in JP-A No. 63-9108, the surface of rare earth permanent magnets is coated using an organic electrolytic plating method that uses an organic solvent, which is a non-aqueous plating solution, as an electrolytic bath (such as a tetrahydrofuran bath). Methods of coating are also known. However, even with non-aqueous plating solutions, since the organic solvent itself is a polar solvent, it tends to contain water, and since organic solvents have low solubility for salts, they can even reduce conductivity. It has the disadvantage of being stored away, which is unique to organic electrolytes.

Furthermore, in order to compensate for the drawbacks of organic solvents, it is necessary to use the internal oxidation factor of the R2T14B rare earth permanent magnet material, which has a R-Fe solid solution phase that is highly oxidized, with a simple supporting salt used in conventional organic electrolytic plating. However, the current situation is that only plating films that lack gloss and have low adhesion can be formed.

In view of the above drawbacks, the first technical problem of the present invention is to provide an acid-resistant plating method that improves gloss (appearance) and adhesion in an organic electrolytic plating method that does not require a large amount of water or aqueous solution during the plating process. An object of the present invention is to provide an organic solvent electrolytic plating solution for plating films of R2T, B intermetallic compound permanent magnets forming a chemically resistant film.

In addition, the second technical problem of the present invention is to respond to the special internal oxidation factors included in R2T14B intermetallic compound permanent magnets, and to develop plating using a highly versatile supporting salt that can be used in various organic solvents. An object of the present invention is to provide an organic solvent electrolytic plating solution for membranes.

Furthermore, a third technical object of the present invention is to provide an organic solvent electrolytic plating solution for plating films that has increased solubility in organic solvents and also has increased conductivity of the supporting salt according to the present invention. .

Furthermore, a fourth technical object of the present invention is to provide an organic solvent electrolytic plating solution for plating films that eliminates external oxidation factors during the organic electrolytic plating process.

[Means for Solving the Problems] According to the present invention, an organic electrolytic plating method using an organic solvent electrolytic plating solution containing a metal salt containing one or more metal elements, a supporting salt, and the remainder being an organic solvent. , R, Fe, B
Used in the organic electrolytic plating process to form a plating film on the surface of R2T, 4B intermetallic compound permanent magnet material (here, R is a rare earth element containing Y, and T is a transition metal) whose main component is In the organic solvent electroplating solution for plating film, the supporting salts include: (R', BO, (R'' represents H or an alkyl group).
, MBO2 (M represents H or an alkali metal), M'
BO, (M' represents an alkali metal.

) + M' 28 x 0.3x+2)y□(x is 2
is an even number greater than or equal to ); ■ an alkali metal or tetraalkylammonium XO4- salt containing at least one of M' XO4 and R' 4 NXO4 (X represents a halogen); ■ M' BX,-salt of an alkali metal and tetraalkylammonium containing at least one of BX4 or R' NBX4, and PI3-salt of an alkali metal and tetraalkylammonium containing at least one of M' PI3 and R' NPX6. and ■M' CX 3 S 03 and R' 4 N CX
alkali metal and tetraalkylammonium cx, so3 salts containing at least either one of 3S O3 and an alkali metal R' C containing OR'C00M'
An organic solvent electroplating solution for plating films of R2T, B intermetallic compound permanent magnets is obtained, which is characterized by containing at least one selected from the group consisting of salts.

According to the present invention, the supporting salt comprises: oxalic acid (H3BO3) as the halonic acid-based compound, and oxalic acid (H3BO3) as the tetraalkylammonium
Tetrabutylammonium perchlorate 1 [CHs (C
An organic solvent electroplating solution for a plating film of an R2T14B intermetallic compound permanent magnet is obtained, which is characterized by containing H2) 3] 4 NCN O4).

According to the present invention, the organic solvent electroplating solution for the plating film of the R2T14B intermetallic compound permanent magnet contains an accelerating crown compound as a compound added together with the supporting salt, whereby the organic solvent contains An organic solvent electroplating solution for plating films of R2T, 4B intermetallic compound permanent magnets is obtained, which is characterized by forming an anion complex and activating metal cations.

According to the present invention, R, Fe, B,
Used in the organic electrolytic plating process to form a plating film on the surface of R2T, 4B intermetallic compound permanent magnet material (here, R is a rare earth element containing Y, and T is a transition metal) whose main component is The organic solvent electroplating solution for plating film contains at least 11]i of trifluoroacetate, acetate, and perchlorate as the metal salt, and the salt includes Al, Pb, Sn, and Cr. , Ni.

An organic solvent electroplating solution for plating films of R2T14B intermetallic compound permanent magnets, which is characterized by containing at least one of Cu and Zn, is obtained.

According to the present invention, R, Fe, B,
Used in an organic electrolytic plating process to form a plating film on the surface of an R2T I4B4B metal compound permanent magnet material (here, R is a rare earth element containing Y, and T is a transition metal) whose main component is An organic solvent electroplating solution for plating films of R2T14B intermetallic compound permanent magnets, characterized in that the organic solvent contains at least one of a protic amphoteric solvent and a proton-accepting solvent. A solvent electroplating solution is obtained.

According to the present invention, the organic solvent contains at least 18 of methanol (CH,OH) and ethanol (C2H50H) as the protic amphoteric solvent, and formamide (ICON) as the proton-accepting solvent.
H2).

An organic solvent electroplating solution for plating films of R2T14B intermetallic compound permanent magnets is obtained, which is characterized by containing at least one type of dimethylformamide (ICON (CH3)21acetamide (CH3CONH2)).

According to the present invention, in the organic solvent electroplating solution for plating films of any of the R2T 14B intermetallic compound permanent magnets, hypophosphite MH2PO2 and sulfamic acid (C7R5NO3S) are added as stabilizers together with the supporting salt.
) An organic solvent electroplating solution for plating films of R2T14B intermetallic compound permanent magnets is obtained, which is characterized by containing at least one of the following.

According to the invention, any of the above R'x T 14B
In the organic solvent electroplating solution for plating films of intermetallic compound permanent magnets, the amount of the metal salt added is substantially 0.1 to 1.
2.0 mol/1, the amount of the supporting salt and the stabilizer added is 0.005 mol/R or more, and the remainder is the organic solvent for plating films of R2T, 4B intermetallic compound permanent magnets. An electroplating solution is obtained.

According to the present invention, the R2T4B characterized in that the water content contained in the organic solvent electroplating solution for plating film of any of the R2T, 4B intermetallic compound permanent magnets is substantially 3000 ppm or less. An organic solvent electroplating solution for plating films of intermetallic compound permanent magnets is obtained.

[Summary of the invention]

The organic electrolytic plating solution of the present invention can be said to be a plating method in which a solution in which a metal salt and a supporting salt to form a plating layer are dissolved in an organic solvent is used as an electrolytic solution.

A supporting salt of the present invention (first and second claims) Here, the supporting salt is in a state separated into ions (E, NH, Cg
-NH,"+,Cfi-), and is known to impart conductivity to the solution. However, the present inventors believe that depending on the selection of the properties of the supporting salt, R2T, , B rare earth magnets It was discovered that this method not only improves the conductivity of the material, but also has a significant effect on the properties of the plating film (adhesion, gloss, etc.), crystal grain shape, and corrosion resistance, leading to the present invention. be.

Therefore, as a result of various experiments, the present inventors have found that they not only improve the conductivity of the plating bath, but also improve the corrosion resistance, adhesion, and Improves appearance (gloss) and also improves R2
A supporting salt matching the characteristics of T, 4B rare earth permanent magnet material was obtained.

When these supporting salts according to the present invention are expressed in the form of X+Y'',
1Y- is X+...H"M" (alkali metal), NR"(
R: H or alkyl group) Y-...Hallic acid anion, XO.

BI3-, PI3-, CXI 5O3RC00-N
Oi -S O4'-, etc cx: "Rogen
R'H or alkyl group) ion, but R
x+, which meets the characteristics of 2T14B rare earth permanent magnet material;
The key point is the combination of y-.

In other words, 1. Even if cations such as H+M+ and NR4+ are used as X+ in the above, Y- is N01-
, S04'-, an anion, the plating film has no luster, and the plating film and R2T
, 4B rare earth permanent magnet material has poor adhesion, and R2T, 4B rare earth magnet material with excellent corrosion resistance cannot be obtained.
This is because a discharge reaction of the anion Y- occurs on the electrode surface, and these products and anions increase the oxidizing power in the electrolyte, and the surface of the R, T, B rare earth permanent magnet material in the electrolyte increases. This is because it violates the As a result, the adhesion of the plating film will deteriorate.

Here, by using the supporting salt according to the present invention, the metals that can be plated include Ni, Cr, Cu, and Sn, as in the case of electrolytic plating using a normal aqueous solution.

Metals such as Co can be used, and there are many choices depending on the application. Furthermore, various organic solvents can be used, such as alcohols such as ethanol and methanol, aromatics such as benzene, amides, BPC, hexane, and quinolene. In addition, materials with a high dielectric constant and low viscosity, as well as materials with low vapor pressure and danger due to pollution, etc.
It is preferable to select one with low toxicity.

Moreover, although the supporting salt according to the present invention is different from the supporting salt used in electrolytic plating using a normal aqueous solution, the method thereof is relatively easy and the cost is low.
A monobicyclic crown compound that can be produced at a lower cost and can be said to be extremely effective industrially than the resin coating used as a conventional means of improving corrosion resistance or the dry plating of swine, ivy, etc. (Claim 3): Next, a bicyclic crown compound that increases the solubility of the metal in an organic solvent and increases the conductivity of the supporting salt when used with the supporting salt according to the present invention described above will be described.

In general, organic solvents have a lower solubility of salts than aqueous solutions, which inevitably results in lower reaction rates and lower electrical conductivity.

In order to improve this problem, the present inventors have investigated various compounds that can form complexes with ionized ions, increase solubility in organic solvents, and work together with the supporting salt according to the present invention. As a result, a yielding crown compound capable of clathrating anions was discovered as a compound that satisfies the purpose of the present invention.

Cryptand was effective because this compound included anions and solubilized them in organic solvents, and although electrolytes normally exist in ion pairs in solutions and the solution as a whole is electrically neutral, This is understood to be due to the inclusion of the anion, making it appear as if only the cation existed in the solution.

Metal Salt of the Present Invention (Fourth Claim) Furthermore, in the present invention, various metal salts can be used as solutes. Moreover, since the electrolytic plating solution of the present invention has a wide stable potential range, when a solvent without active hydrogen is used, there will be no simultaneous metal deposition, so electrodeposition from an aqueous solution is usually possible. Another feature of the present invention is that aluminum and titanium salts, which are difficult to use, can be used.

Specifically, triethylaluminum (i(C2H5)
3)2. ) Lifluoroacetic acid di-soquer (N i (C
F3 Coo)2), copper trifluoroacetate (Cu
(CF3Coo)2), perchlorate, etc., but are not particularly limited to these.

Organic Solvent of the Present Invention (Fifth and Sixth Claims) First, the organic solvent will be described in a method for removing external oxidation factors during an organic electroplating process.

Generally, rare earth metal (R) compounds are mainly trivalent ionic compounds. The metal is positive and highly reactive and gradually reacts with cold water as follows.

R+3H20→R+ (OH)3 +3/2H2 It is easily assumed that as the reaction progresses further, the hydroxide produced here becomes an oxide. From this, R2T
It can be seen that when applying an oxidation-resistant film to a 4B alloy, it is necessary to avoid contact with water as much as possible.

Therefore, an organic solvent is used as a substitute for water as a solvent.

Although various organic solvents can be used as the organic solvent for use in the present invention, it is generally preferable to select a solvent having the following properties as the solvent for the organic electrolytic plating bath.

1) Low toxicity and risk.

2) Low viscosity and good conductivity.

3) It has a high dielectric constant and facilitates solute dissolution and dissociation.

In addition, metals that can be plated by the organic electrolytic plating method according to the present invention include Ni
, Cr, Cu, Sn, Co, and other metals, and many choices can be made depending on the application.

In addition, as mentioned above, various organic solvents are used, such as alcohols, aromatics, amides, hexane, xylene, etc., but some have a high dielectric constant and low viscosity, others have low water content and have no affinity for water. Although it is preferable that the water content is low, the water content may be dehydrated before use as shown in the present invention. Further, in consideration of pollution, etc., it is preferable to select a material that has a low vapor pressure, is low in danger, and is low in toxicity.

In view of these points, usable solvents are required to have physical properties such as high dielectric constant, low viscosity, being liquid at around room temperature, and low volatility. Table 1 shows typical organic solvents used.

Margin table below - 1 Solvents used and their physical properties - Moisture content of the present invention: 3000 ppm (Claim 9) Similarly, in the method of removing external oxidation factors during the organic electroplating process, the water content explain.

When using the above-mentioned organic solvents, the most important thing to be careful about is water, but many of these polar solvents dissolve water, so they have the inevitable drawback of containing a large amount of water during the treatment process. be.

This water content is generated at the stage of manufacturing various organic solvents, and the water absorption properties differ depending on the organic solvent, and the water content changes depending on the subsequent storage conditions and use environment.

Especially low molecular weight alcohols such as ethanol and methanol,
Its solubility in water is infinite, and its water absorption is high. There are also other organic solvents that have high water absorption (
formamide etc.). That is, due to the water absorption property of this organic solvent, the water content of the organic solvent itself changes depending on the usage and storage environment.

As a result of studying the effects of various conditions on organic electrolytic plating, the inventors of the present invention have found that the amount of water in the organic solvent and the plating atmosphere can be particularly controlled.

That is, according to the present invention, the water content in the organic solvent for organic electrolytic plating is 3000 ppa+ or less, and the organic electrolytic plating is performed in an atmosphere such as N, Ar, etc. in the plating tank, which is cut off from the atmosphere. It is something.

Thereby, the organic solvent in the present invention is ethanol,
Alcohols such as methanol, aromatics such as benzene, amides, BPC, propylene carbonate, hexane,
Various organic solvents can also be used, such as xylene.

The reason why the amount of water is 3000 ppm or less is because this is the upper limit for obtaining a plating bath with excellent corrosion resistance and gloss.

In the present invention, as a method for reducing the water content in the organic solvent to 3000 pp or less, a commonly used dehydration method using Ca metal, molecular sieve, etc. may be used, and in order to further protect the plating environment, an electrolytic layer Ar, N
It may be placed in an inert gas atmosphere such as No. 2. in particular,
A glove box or the like is preferred.

1. Content of each component of the present invention (Claim 8) If the metal salt used in the present invention is contained in an organic solvent of 0.1 to 2.0 mol/N, a good film can be formed by plating. The concentration can be changed depending on the purpose. In addition, in the region of less than 0.1 mol/Ω, the ability to form a plating film is low, the current efficiency decreases due to coexisting reactions such as hydrogen generation, and the plating time also takes a long time, so the lower limit of the amount of metal salt added is It is necessary to set it to 0.1a+ol/g. In addition, in a region where the amount is more than 2° Omol/II, the undissolved metal salt powder will react with the forming reaction of the plating film due to the non-uniformity of the plating film due to the increase in the reaction rate and the limited solubility of the metal salt in the organic solvent. The upper limit of the amount of metal salt added is 2.0 mol/II! It is necessary to do so.

Supporting salts and stabilizers added to organic solvents include: ■ Supporting salts for electroplating and electrolysis, which provide conductivity during electrolysis; ■ Stabilizers and buffers for plating baths. These additives are used in additives, etc., and the purpose can be achieved by adding only one type of these additives or by adding a mixture of two or more types.

The concentration of supporting salt and stabilizer added was 0.005II.

/f) or more is sufficient to achieve the target plating. In addition, if the amount is less than 0.005 mol/N, it is insufficient to impart conductivity to the plating solution, stabilize it, or buffer it, so the additive should be less than 0.005 mol/N.
It is necessary to do more than that.

As described above, by using the plating solution having the composition of the present invention in organic solvent electrolytic plating, it is possible to obtain a dense and uniform film structure, which has excellent corrosion resistance, excellent adhesion, and has a metallic luster in appearance. Excellent plating film with Nd
It can be obtained on the surface of -Fe-B rare earth permanent magnets and is extremely effective industrially.

[Example] Next, examples of the present invention will be described.

-First Example- A plating test sample was prepared as follows.

First, 33 W t%Nd-
A sintered body having a composition of 10 wt% B#Febap was created, and this sintered body was cut into a size of 10×10×5 (I1g+) to serve as a sample for a plating test.

The above sample was subjected to organic electrolytic plating under the supporting salt and electrodeposition conditions shown in Table 2, and tests under each condition were prepared. Here, methanol (CM, OH) is used as the organic solvent that constitutes the main component of the electrolytic solution, and nickel trifluoroacetate tNi(CF3Coo)2+ is used as the metal salt.

In addition, as a comparison material, ammonium chloride (NH40g)
, lithium nitrate, (LiNOi), and ammonium hydrogen sulfate 1 (NH4) HSO41 were used as supporting salts.

Margin below Here, a corrosion resistance test was conducted on samples (sample Nos. 1 to 35) plated under the electrodeposition conditions shown in Table 2.

The method and conditions are low temperature constant temperature test at 60℃, 9
5% for 2000 hours. Table 3 shows the results of these corrosion resistance tests.

Table 3: Corrosion resistance test results of plating samples obtained with various supporting salts Next, in order to compare the organic electrolytic plating according to the first example with the plating formed by a normal Watt bath, Samples plated with Ni in the Hewat bath of the Nd-Fe sintered body used and the methanol-Ni salt-N a 2 sample of the first example
SI for Ni-plated samples formed from B40t bath
Analysis by MS was performed.

The results are shown in FIGS. 1 and 2. Here, FIG. 1 shows the results of a plating sample using a Watt bath, and FIG. 2 shows the results of organic electrolytic plating (Ni salt-Na2BaOt-methanol).

From Figures 1 and 2, plating using a normal Watt bath,
It can be seen that there are many substances that oxidize Nd-Fe-B, such as H20,02.

In addition, in the organic electrolytic plating of this example, although many peaks of C-H compounds were observed, no peaks with adverse effects such as H2O,02 were observed at all. It was found that the impurities contained in the plating layer are clearly different from plating.

-Second Example- 33wt%Nd-1 by normal powder metallurgy method
, OB-Febag was obtained. This sintered body was cut out to a size of 110 x 10 x 5 (+m) to obtain several T and R pieces for plating tests.

Next, under the plating conditions shown in Table 4, organic electrolytic plating (a, b, c) according to this example and supporting salt N as a comparative material were applied.
Samples were prepared under the conditions of organic electrolytic plating using H4Cf1 (ammonium chloride) (Comparative Example 1) and electrolytic Ni plating using a normal Watts bath (Comparative Example 2).

The margins below are these plated test pieces 80℃895% humidity test 5
It was applied for 00 hours. The results of this corrosion resistance test are shown in Table-5.

Table 5 shows that the samples using the supporting salts according to the examples of the present invention have significantly better corrosion resistance than the comparative materials.

Although the Nd/Fe conflict B has been described in the following margins, it can be easily inferred that similar effects can be expected for rare earth (R)-T (transition metal)-B alloys including Y.

1. Third Example - 33 wt%Nd-1, O
Create a sintered body having a composition of wt%B-Febal,
This sintered body was cut into a size of 1010×10×5 (a) and used as a sample for a plating test.

The above samples were subjected to organic electrolytic plating under the electrodeposition conditions in which the crown compound shown in Table 6 was added, and samples under each condition were prepared. Table 6 shows that by adding the crown compound, these compounds strongly coordinate with the Ni ions in the electrolyte, thereby promoting the dissociation of the metal salt and increasing the mobility of the ions. As a result, when the crown compound is added, less voltage is required to flow the same current than when the crown compound is not added.

In this example, a crown compound that easily coordinates with Ni ions was selected, but when alkali metal ions are used as the supporting salt, the same effect can be obtained by selecting a crown compound that easily coordinates with these alkali metal ions. It is easy to infer that this can be expected.

Next, a sample plated under the electrodeposition conditions shown in Table 6 (Nα
36-39) corrosion resistance test (constant temperature and humidity test at 60℃,
95%, 2000 hr).

Table 7 shows the results of these corrosion resistance tests.

The following margin - Fourth Example - 33 wt%Nd-1,0 by normal powder metallurgy method
A sintered body having a composition of B-FeBAl was obtained. This sintered body was cut into a size of 1010 x 10 x 5 (a) to obtain several T and P pieces for plating tests.Next, as a plating method, organic electrolytic plating with methanol-boric acid-trifluoroacetic acid N1 was applied to the above sample. The electrolytic conditions at this time were a bath temperature of 40°C and a current density of 3 (A/dr&).Here, in order to detect the difference due to the water content in methanol, methanol whose water content was adjusted in advance was The water content of these five types of methanol was measured using the Karl Fischer method, and found to be 50 ppts.

280ppm, 630ppm, 620ppm
m, 1540ppm, 2860pp11,351
It was 0ppa+, 5780ppm. Plating was performed using these seven types of methanol under the above plating conditions.

The obtained 7 types of plated materials were subjected to appearance observation and 80"Cr95% constant temperature constant temperature test for 500 hours.
r was applied. Table 8 shows the test results.

When measured, 50pp layer, 28Opp layer, 630p layer
pm, 620ppm, 1540
ppm, 2860ppm.

They were 3510 ppm and 5780 ppm. Plating was performed using these seven types of methanol under the above plating conditions.

The obtained 7 types of plated materials were subjected to appearance observation and 80@Cr95% constant temperature constant temperature test for 500 hours.
r was applied.

Table 8 shows the test results. From Table 8, the water content in Rakuchu is 3
000 ppm or less, a plated layer with excellent appearance and good corrosion resistance can be obtained.

Below margin - Example 5 - 33Nd-1゜0B-FebaΩ obtained in the fourth example
(wt%), an electrolyte of methanol-boric acid-Ni trifluoroacetate was used as in the fourth example, an air-open plating bath of the comparative example, and a glove box according to the present invention. Two types of plating were performed in plating baths placed in an Ar atmosphere.

Next, these samples were subjected to an external appearance inspection and a constant temperature test at 80°C x 95% for 1000 hours. Table 8 shows the test results.

From Table 9, it can be seen that the samples treated in the Ar atmosphere are superior in both appearance and corrosion resistance.

Margin below Example 6- A plating test sample was prepared as follows.

33wt%Nd-1, Ovt% by normal powder metallurgy method
Producing a sintered body having a composition of B-F e bat,
This sintered body was cut into a size of 1010x10x1,
This was used as a plating test sample.

This sample was subjected to organic electrolytic plating under the plating solution composition and electrodeposition conditions shown in Table 10 to produce samples under each condition (Samples 40 to 63).

As a comparative material, a sample was also prepared using N i (NO3) 2 as a metal salt (sample 64°65).

Furthermore, samples 66 and 67 were also prepared by ordinary aqueous electrolytic plating (Watts bath) AfI ion blating.

Samples plated under the electrodeposition conditions shown in Table 10 (sample magnet 4
Corrosion resistance tests of 0 to 67) were conducted.

The method and conditions are constant temperature and humidity test at 60℃, 95%
It was applied for 2000 hours.

Table 11 shows the results of these corrosion resistance tests. The samples tested were those prepared under the electrodeposition conditions shown in Table 10 that yielded the best plating film.

From Table 11, it can be seen that samples 40 to 63 plated by the organic electrolytic method using the metal salt according to the present invention have significantly better corrosion resistance than comparative materials 64 to 67.

Beneath #0 Red Rust Precipitation This will significantly erode the Nd-Fe-B magnet surface and prevent electrodeposition on the magnet surface in the case of nitric acid-based metal salts, but in the case of acetic acid-based and perchloric acid This result may be due to the fact that the influence of metal salts is extremely small.

Above, Nd-Fe-B system was described as an intermetallic compound permanent magnet, but R (rare earth element including Y) -T (
It can be easily inferred that similar effects can be expected for transition/metal)-B alloys as well.

Margin below -Seventh Example- A plating test sample was prepared as follows.

By ordinary powder metallurgy method, 33vt%Nd-1, Ovt.
A sintered body having a composition of %B-Febal was prepared, and this sintered body was cut into a size of 10 x 10 x 1 m+s to prepare a sample for a plating test.

The above samples were subjected to organic electrolytic plating under the plating solution compositions and electrodeposition conditions shown in Tables 12 and 13 below to produce samples under each condition.

The upper limit of the bath temperature was set to room temperature, which was slightly lower than the lower boiling point temperature.

As comparative materials, acetonitrile (CH, CN), ethyl methyl ketone (CH3C0C2Hs), [materials that are difficult to bond with metal ions and difficult to form metal complexes that are easy to electrodeposit]
A sample was also prepared when using this as an organic solvent. Furthermore, samples were also prepared by conventional aqueous electrolytic plating (Watts bath') and l-ion blating.

Corrosion resistance tests were conducted on samples (sample Na 68 to 89) plated under the electrodeposition conditions shown in Table 14 Table 12 and Table 13 below. The method and conditions are constant temperature and humidity test at 60℃ x 95℃ humidity.
%2000hr. Table 14 shows the results of these corrosion resistance tests. The samples compared are shown in Table-12 and Table-1.
A sample prepared under the conditions in which the best plating film was obtained under the conditions of No. 3 is shown below.

From Table 14 below, it can be seen that the samples plated by the organic electrolytic method using an organic solvent according to the present invention have significantly better corrosion resistance than the comparative materials.

Above, we have described the Nd-Fe-B system as an intermetallic compound permanent magnet, but the same effect can be expected with the R (rare earth element including Y)-T (transition metal)-B system alloy. This can be easily inferred.

1.Eighth Example- A plating test sample was prepared as follows.

By ordinary powder metallurgy method, 33vt%N d -1,O
Create a sintered body having a composition of wt%B-Febal,
This sintered body was cut into a size of 10 x 10 x 1 mm and used as a sample for a plating test.

The above samples were subjected to organic electrolytic plating under the plating solution composition and electrodeposition conditions shown in Table 15 to create samples under each condition.

As a comparative material, ordinary aqueous electrolytic plating (Wat
Samples were also prepared using AfI ion blating.

Sample plated under the electrodeposition conditions shown in Table 15 (Sample Nα
A corrosion resistance test of 90 to 120) was conducted.

The method and conditions are constant temperature and humidity test at 60℃ x 95?6
It was applied for 2000 hours. Table 16 shows the results of these corrosion resistance tests.

Note that the tested samples are those prepared under the conditions in Table 15 under which the best plating film was obtained.

From Table 15, it can be seen that the samples plated by the organic electrolytic method using the organic solvent electroplating solution according to the present invention have significantly better corrosion resistance than the comparative materials. Moreover, it can be seen that the effect is even better when the metal salt concentration is 0.11 Ilol/J2 or more.

[Effects of the Invention] As explained above, by using the supporting salt of the present invention in organic electrolytic plating, a plated layer with extremely good corrosion resistance, excellent adhesion, and a beautiful appearance with metallic luster can be formed using Nd-Fe. -B It can be obtained on the surface of the magnet and is extremely effective industrially.

In addition, by using the crown compound of the present invention in organic electrolytic plating, it forms a complex with ionized ions, increases the solubility in organic solvents, and works together with the conductivity of the supporting salt of the present invention. can be increased.

Furthermore, according to the present invention, the amount of water in the organic solvent serving as the electrolyte is set to 3000 ppm or less, and the plating bath atmosphere is set to an inert atmosphere such as Ar or N2, thereby preventing moisture and oxygen from entering from the atmosphere. Because it can prevent such things as
It is possible to reduce as much as possible the amount of water and greedy oxygen that have an adverse effect during the plating process.

Further, according to the present invention, an organic electrolytic plating method is used.
In the step of forming an oxidation-resistant plating layer on the surface of the Nd-Fe-B intermetallic compound permanent magnet, triple oleoacetate of a transition metal (including AΩ, Sn, Pb, CrNi, Cu, and Zn) is used as a metal salt. By using at least one of , acetate, and perchlorate, it is possible to obtain a plating film with excellent corrosion resistance, adhesion, and appearance on the Nd-Fe-B magnet, and it has excellent oxidation resistance. An excellent Nd-Fe-8 intermetallic compound permanent magnet can be obtained.

Further, according to the present invention, the organic solvent-based electroplating solution has a composition of 0.5% of the metal salt. t ~2.0 fflol/1, the additives (supporting salts and stabilizers) dissolved in the organic solvent 0.0
By using an organic electroplating solution consisting of 05 mol/11 or more and the balance being the organic solvent, a plated film with excellent corrosion resistance, adhesion, and appearance can be obtained on the Nd-Fe-B intermetallic compound magnet. , Nd with excellent oxidation resistance
-Fe-B intermetallic compound permanent magnets can be obtained.

In addition, as an intermetallic compound rare earth permanent magnet, Nd-F
Although I mentioned the e-B system, R (a rare earth element containing Y)
It can be easily inferred that similar effects can be expected for -T (transition metal)-B alloys.

[Brief explanation of drawings]

Figure 1 shows organic electrolytic plating (Ni salt-Na2B407-
Fig. 2 shows the results of SIMS analysis of a plated sample using a Watt bath.

Claims (1)

[Scope of Claims] 1) R, Fe, and B are produced by an organic electrolytic plating method using a metal salt containing one or more metal elements, a supporting salt, and an organic solvent electrolytic plating solution with the remainder being an organic solvent. For plating films used in organic electrolytic plating processes to form plating films on the surface of R_2T_1_4B intermetallic compound permanent magnet materials (here, R is a rare earth element containing Y, and T is a transition metal) as the main component. In the organic solvent electroplating solution, as the supporting salt, [1] R'_3BO_3 (R' represents H or an alkyl group), MBO_2 (M represents H or an alkali metal), M'BO_3 (M' represents an alkali metal.), M'_2B_xO_(_3_x_+_2_)_/_
[2] An alkali metal containing at least one of M'XO_4 and R'_4NXO_4 (X represents a halogen); Tetraalkylammonium XO_4^-
[3] BX_4^-salt of an alkali metal and tetraalkylammonium containing at least one of M'BX_4 or R'NBX_4; [4] containing at least one of M'PX_6 and R'NPX_6 PX_6^-salt of alkali metal and tetraalkylammonium, [5] M'CX_3SO_3 and R'_4NCX_3S
Alkali metal and tetraalkylammonium CX_3SO_3^- containing at least one of O_3
salt and R'COO of alkali metals including [6] R'COOM'
An organic solvent electroplating solution for plating films of R_2T_1_4B intermetallic compound permanent magnets, characterized by containing at least one selected from the group consisting of salts. 2) The supporting salt according to claim 1 includes: boric acid (H_3BO_3) as the boric acid compound; and tetrabutylammonium perchlorate {[CH_3(
An organic solvent electroplating solution for plating film of R_2T_1_4B intermetallic compound permanent magnet, characterized by containing CH_2)_3]_4NClO_4}. 3) The organic solvent electroplating solution for plating films of R_2T_1_4B intermetallic compound permanent magnets according to the first or second claim, further comprising a bireducing crown compound as a compound added together with the supporting salt, whereby the An organic solvent electroplating solution for plating films of R_2T_1_4B intermetallic compound permanent magnets, which is characterized by forming an anion complex in an organic solvent to activate metal cations. 4) R_2T_1_4B metal containing R, Fe, and B as main components by an organic electrolytic plating method using a metal salt containing one or more metal elements, a supporting salt, and an organic solvent electrolytic plating solution with the remainder being an organic solvent. In an organic solvent electroplating solution for a plating film used in an organic electrolytic plating process to form a plating film on the surface of an intermediate compound permanent magnet material (where R is a rare earth element containing Y, and T is a transition metal). , the metal salt contains at least one of trifluoroacetate, acetate, and perchlorate, and the salt includes Al, Pb, Sn, Cr, Ni, Cu,
R_ characterized by containing at least one kind of Zn
2T_1_4B Organic solvent electroplating solution for plating films of intermetallic compound permanent magnets. 5) R_2T_1_4B metal containing R, Fe, and B as main components by an organic electrolytic plating method using a metal salt containing one or more metal elements, a supporting salt, and an organic solvent electrolytic plating solution with the remainder being an organic solvent. In an organic solvent electroplating solution for a plating film used in an organic electrolytic plating process to form a plating film on the surface of an intermediate compound permanent magnet material (where R is a rare earth element containing Y, and T is a transition metal). , R_2T_1_4, characterized in that the organic solvent contains at least one of a protic amphoteric solvent and a proton-accepting solvent.
B Organic solvent electroplating solution for plating films on intermetallic compound permanent magnets. 6) In the organic solvent according to claim 5, the protic amphoteric solvent is methanol (CH_3OH).
, ethanol (C_2H_5OH), and the proton-accepting solvents include formamide (HCONH_2), dimethylformamide {HCON(CH_3)2}, acetamide (CH_
3CONH_2) An organic solvent electroplating solution for plating films of R_2T_1_4B intermetallic compound permanent magnets. 7) Any R_2T_1_ described in the first to sixth claims
In the organic solvent electroplating solution for plating film of 4B intermetallic compound permanent magnet, hypophosphite MH_2PO_2 and sulfamic acid (C_7H_5) are added as stabilizers together with the supporting salt.
An organic solvent electroplating solution for a plating film of an R_2T_1_4B intermetallic compound permanent magnet, characterized by containing at least one of the following: NO_3S). 8) Any R_2T_1_ described in the first to seventh claims
In the organic solvent electroplating solution for plating films of 4B intermetallic compound permanent magnets, the amount of the metal salt added is 0.1 to 2.0 mol/l, and the amount of the supporting salt and the stabilizer added is 0. .005mol/l
As described above, an organic solvent electroplating solution for a plating film of an R_2T_1_4B intermetallic compound permanent magnet, characterized in that the remainder consists of the organic solvent. 9) Any R_2T_1_ described in the first to eighth claims
The water content contained in the organic solvent electroplating solution for plating film of 4B intermetallic compound permanent magnet is substantially 3000p.
An organic solvent electroplating solution for plating films of R_2T_1_4B intermetallic compound permanent magnets, characterized in that the electroplating solution is pm or less.