JPH01123079A - Amorphous ni-p alloy - Google Patents

Abstract

PURPOSE:To provide an amorphous Ni-P alloy capable of maintaining the nonmagnetic state even after heating by carrying out electroless plating with an Ni-P plating bath contg. a citric acid component in a complexing agent in a specified molar ratio to Ni ions. CONSTITUTION:A plating bath contg. Ni ions, an Ni ion reducing agent, an Ni ion complexing agent, a pH adjusting agent and a sec phosphorus deposition accelerator or further contg. a prim. phosphorus depositing agent is prepd. so that a citric acid component in the complexing agent is contained in 1:8.0-1:10.0 molar ratio to Ni ions (Ni ions: C6H5O7). Other complexing agent may be incorporated by an equivalent amt. and a group IVa or VIa metal may be dissolved in 1:>=0.15 molar ratio to Ni ions. An amorphous Ni-P alloy layer is formed on the surface of copper foil, etc., by electroless plating with the plating bath. The alloy layer has corrosion and wear resistances and does not change the properties even when heated.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides amorphous N that can maintain a non-magnetic state even after heating.
Regarding i-P alloy. Furthermore, <prior art> regarding an amorphous Ni-P alloy having corrosion resistance and wear resistance. Conventionally, in order to make a Ni-P alloy amorphous, the P content is approximately 7. It is known that the content must be at least atomic percent. Furthermore, in order to stabilize the amorphous state at room temperature, the P content must be 15 to 25%, and the present inventors prepared a plating bath with the following composition and electroless P content is 15-25% depending on plating
proposed a method for manufacturing N1-P alloy (see Japanese Patent Laid-Open No. 60-248882).

Bath composition (comparative example 2), (mol /j2
) Nickel sulfate 0.13 Sodium hypophosphite 0.09 Sodium citrate
0.17 Satucharin Sodium 0.0042
C+oHIsN 2 Na s O70,001!7
Adjust pH (=5.0) with dilute sulfuric acid and aqueous ammonia.1 with pure water.
I suddenly thought about it.

In addition, in the above ingredients, nickel sulfate is a nickel ion, sodium hypophosphite is a nickel ion reducing agent, sodium citrate is a nickel ion complexing agent,
Saccharin sodium is a stress reducer, C+oHIsN
2 N aso 7 refers to the primary phosphorus precipitation promoter. Note that sodium citrate, which is a complexing agent, is completely 'f!' in the plating bath. There are 11111t. The citric acid component is expressed as CaLOy, with a mo of nickel Kel ion.
l ratio of 1/3.5 (nickel ion/CaHsQy
; the same applies hereafter).

<Problems to be Solved by the Invention> However, when the N1-P alloy manufactured by the above invention is heated, it changes from an amorphous state to a crystalline state, similar to conventional alloys of this type. (See Comparative Example 2 in Table 1), and the desired properties such as wear resistance, corrosion resistance, catalytic properties, and non-magnetic properties are no longer exhibited.

Such alloys can be used in the field of electronics (for example, ■ Formation of conductor circuits, ■ As a protective film on the surface of conductor circuits and parts of connectors, ■ As sliding surface layers for magnetic heads and rotary encoders, and as surface reinforcement layers for contact parts of switches. etc.), there is a risk that the temperature will rise due to the magnetic field and sliding friction generated around the conductor when it is moving, and due to sparks at the contact point, causing it to change to take on properties such as magnetic material. Furthermore, during device assembly, the temperature may rise due to the influence of soldering irons and other heat processing jigs. When the alloy is denatured in this way, problems arise such as causing magnetic interference with peripheral elements, inhibiting high-speed running of the magnetic medium, and causing noise generation.

Particularly, as a countermeasure against the above problem, noble metals (Rh, Pd, Pt, AU, etc.) which have no magnetic influence even in the crystal structure are used, but this is not preferable because the manufacturing cost increases.

Therefore, it is an object of the present invention to provide an amorphous N1-P alloy that is an inexpensive alternative to such noble metals and does not change even when heated.

<Means for Solving the Problems> In order to achieve the above object, the present inventor has disclosed
As a result of improving the invention proposed in Publication No. 882, it was discovered that when manufacturing an amorphous N1-P alloy by electroless plating, it is sufficient to use a predetermined amount of a nickel ion complexing agent. I came up with an invention.

That is, the first invention is a plating bath that maintains a non-magnetic state even after heating at 600°C and contains the following components (a) or (b), wherein the citric acid component of the complexing agent but for nickel ions. PAL ratio 1:8.0 to 1:10
．． This is an amorphous Ni--P alloy manufactured by electroless plating using a complexing agent containing 0 or an equivalent amount of another complexing agent.

(a) Nickel ion Nickel ion reducing agent Complexing agent for nickel ions pH adjuster Secondary phosphorus precipitation accelerator.

(a) Nickel ion Reducing agent for nickel ions Complexing agent for nickel ions pH adjuster First phosphorus precipitation promoter and second phosphorus precipitation promoter Also, second phosphorus precipitation promoter
The invention is a plating bath that maintains a non-magnetic state even after heating at 600°C, has corrosion resistance against nitric acid (69.8%), and contains the above-mentioned component (a) or (b). The citric acid component of the complexing agent is contained in an lll01 ratio of 178.0 to 1:10.0 with respect to nickel ions, or an equivalent amount of other complexing agents is contained, and the periodic law of the elements is The rVa group or VIa group metals in the table are nickel ions in a mol ratio of l:o, 15(
It is an amorphous Ni-P alloy manufactured by electroless plating using dissolved nickel ions (two metals) or more.

<Detailed explanation of means> The above means will be explained in detail below.

First, a plating bath for forming the amorphous N i -P alloy of the ζ first invention will be described.

The plating bath contains (1) nickel ions, (2) a reducing agent for nickel ions, (2) a complexing agent for nickel ions, (2) a secondary phosphorus precipitation promoter, (2) a primary phosphorus precipitation promoter, and (2) other agents.

■Nickel ions Nickel ions are usually added in the form of salts (nickel sulfate, nickel chloride, etc.), and 0.03~
Contains 0.20 mol (hereinafter, 0.03 to 0.2
0Iloj/It).

■Nickel ion reducing agent Sodium hypophosphite is used as the nickel ion reducing agent. Addition amount is 0.05-0.40mol/11
shall be.

■Complexing agents for nickel ions Examples of complexing agents for nickel ions include oxycarboxylic acids and their salts such as citric acid, succinic acid, tartaric acid, and gluconic acid, and polyapoliaminocarboxylic acids such as aminoacetic acid and EDTA, or two or more thereof. It will be done.

The amount contained in the plating bath is citric acid (C:6H507
present in the plating bath), the ll1O1 ratio to nickel ions is 1:8. O~1: 10.0
shall be. For other complexing agents, such as succinic acid, the amounts are comparable to those for citric acid, depending on the respective complexing capacity (see Example 6.7).

In the case of citric acid, mo for nickel ion
When the l ratio is less than 1:8.0, nonmagnetism cannot be maintained when heated at 600°C (see Comparative Example 3°4). Also,
If the molar ratio to nickel ions exceeds 1710.0, the deposition rate of plating decreases, which is not preferable. Note that even when the molar ratio exceeded 1/10.0, the amorphous N1-P alloy was able to maintain a nonmagnetic state when heated at 600°C.

The above amount of citric acid is usually added to the plating bath as an alkali metal salt (the same applies to other oxycarboxylic acids). In this case, when adding it as a sodium salt, the ll1O1 ratio of nickel ions and sodium ions is set to 1.
:1.9 to 1:3.5 (nickel ion:sodium ion; the same applies hereinafter) is preferable. If the ratio is less than 1:1.9, there will be a problem that the copper plate will be eroded when the copper plate is used as the material to be plated. Also, 1:3.5
It is not necessary to have sodium ions present in excess of .

Furthermore, when adding as an alkali metal salt such as lithium or potassium, the amount of the alkali metal ion needs to be adjusted in relation to the second phosphorus precipitation promoter described later.

■Second phosphorus precipitation accelerator As the secondary phosphorus precipitation accelerator, one or more types selected from ammonium sulfate, lithium sulfate, potassium sulfate, and ammonium sulfate shown in the above-mentioned publications can be used. .

Furthermore, while considering this invention, the inventor discovered the second
We discovered that lithium ions are important as phosphorus precipitation promoters. In other words, in addition to the above-mentioned secondary phosphorus precipitation promoters, lithium chloride, potassium chloride, sodium chloride, lithium bromide, potassium bromide, sodium bromide, lithium nitrate, potassium nitrate, sodium nitrate, lithium phosphate, phosphorus Inorganic salts such as acid potassium, sodium phosphate, lithium oxalate, potassium oxalate, sodium oxalate, sodium sulfate, lithium acetate, potassium acetate,
Sodium acetate, lithium citrate, potassium citrate, sodium citrate, lithium tartrate, potassium tartrate, sodium tartrate, lithium lactate, potassium lactate,
Organic salts such as sodium lactate, lithium oxalate, potassium oxalate, sodium oxalate, lithium stearate, potassium stearate, sodium stearate, etc.-f
ill or 2 ff11 or more can be used. Note that this alkali metal ion may be added together with a complexing agent component (see each example).

The amount of alkali metal ions as the second phosphorus precipitation promoter in the plating bath is 1:0.50 (nickel ions:alkali metal ions:
The same applies hereinafter) or more is preferable. 1 : 0.5
If it is less than 0, a non-magnetic N1-P alloy cannot be obtained (
(See Comparative Example 7 in Table 1).

■First phosphorus precipitation accelerator The first phosphorus precipitation accelerator includes C
+aHISN 2 N a 307 (hereinafter referred to as HE
DTA) can be used.

Furthermore, while studying this invention, it was discovered that other amines also act as primary phosphorus precipitation promoters.

As amines applicable to the primary phosphorus precipitation promoter, ED
Examples include TA, nitriloacetic acid, aminoacetic acid, diethylenetriamine/triacetic acid, diethylenetriamine/pentaacetic acid, iminodiacetic acid, and cyclohexylenediamine/tetraacetic acid. Note that these amines are added to the plating bath either alone or in the form of their alkali metal salts.

The first phosphorus precipitation promoter and the second phosphorus precipitation promoter other than those shown in the above-mentioned publications are used in the case of a plating bath containing a normal amount of a nickel ion complexing agent - in the case of an amorphous N1-P alloy. This also applies to materials that change into magnetic materials by heating (see Comparative Examples A to G in Table 3).

These secondary phosphorus precipitation accelerators and ■ primary phosphorus precipitation accelerators are:
One or both of the secondary phosphorus precipitation promoters are added to the plating bath.

■Other chemicals Other chemicals contained in the plating bath include - pH adjusting agents such as dilute sulfuric acid, dilute hydrochloric acid, and ammonia (this adjusts the pH of the plating bath to 5.0 to 5.2. ),
pH buffering agents such as components with small dissociation constants such as inorganic acids, organic acids and their alkali salts, stress I such as saccharin sodium, etc.
Examples include H& agents.

Next, a plating bath for forming the amorphous Ni-P alloy of the second invention will be explained.

This plating bath is the same as the plating bath of the first aspect of the invention described above, in which a metal of group IVa or group Vra of the periodic table of elements is further dissolved.

Zirconium is preferred among the IV a group metals, and chromium is preferred among the a group metals. These metals are zirconium chloride and zirconium oxychloride.

It is added to the plating bath in the form of zirconium sulfate, zirconium oxysulfate, chromium sulfate, chromium chloride, potassium chromium sulfate, chromium acetate, chromium nitrate, chromium ammonium sulfate, chromium bromide, etc.

The amount of the metal added is m relative to nickel ions.

The ratio is 1:0.15 (nickel ion:the metal; the same applies hereinafter) or more. If it is less than 1:0.15, it is not preferable because the corrosion resistance is poor (see Comparative Example 9 in Table 2). Also,
According to the studies of the present inventors, there is no need to add more than 1:1.20.

Using each of the above plating baths, electroless plating is performed through numerical operations. The material to be plated is not particularly limited, and may include wood and other metals, ceramics, semiconductors, plastics, etc., but in the case of materials other than metals, pretreatment (etching, formation of a catalyst layer, etc.) is required.

<Effects of the Invention> The amorphous Ni-P alloy of the first invention described above has the following characteristics:
Even when heated at 600°C, it can maintain its non-magnetic state. As a result, it can be used in the field of electronics (for example, ■ Formation of conductor circuits, ■ As a protective film on the surface of conductor circuits and parts of connectors, ■ As a sliding surface layer for magnetic heads and rotary encoders, and as a surface reinforcement layer for contact parts of switchgears. etc.) will be available.

Since this amorphous Ni--P alloy is manufactured by electroless plating, it can be formed to be homogeneous and have a uniform thickness, and has the advantage of being inexpensive.

The fact that the amorphous Ni-P alloy of this invention maintains its non-magnetic state even when heated at 600°C means that the N1-P alloy is amorphous even when heated at 600°C. It is assumed that quality can be maintained.

Even when heated at a temperature below 600°C (e.g. 270°C), due to the self-heating reaction of the amorphous Ni-P alloy,
It is considered that the amorphous Ni-P alloy is heated to a temperature higher than the heating temperature.

In addition to the effects of the amorphous Ni-P alloy of the first invention, the amorphous Ni-P alloy of the second invention has the following properties:
9.8%).

In this specification, "having corrosion resistance to nitric acid (69.8%)" means amorphous N1-P with a thickness of 10 μm.
This means that the alloy layer does not disappear when the alloy layer is immersed in nitric acid (89.8%) for 14 hours or more.

In addition, the fact that it has corrosion resistance to nitric acid (Ii 9.8%) indicates that the amorphous Ni-P alloy of the second invention has corrosion resistance higher than that of a normal N1-P alloy. Corrosion resistance to IN to 2N hydrochloric acid is usually examined. Also,
Corrosion resistance against concentrated hydrochloric acid (35%) has also been confirmed through studies by the present inventors.

Along with such improvement in corrosion resistance, the amorphous N of the second invention
It is presumed that the i-P alloy also has improved wear resistance.

<Example> Hereinafter, an example for confirming the above effects will be described.

The plating bath for the first invention example and the plating bath for the comparative example each contain the components shown in Table 1.

Using such a plating bath (90°C), 10% of the copper foil was coated on both sides of a 20 μm x 5 cm x 5 cm copper foil by electroless plating.
An amorphous N1-P alloy layer with a thickness of μm was formed. Comparative Example 8 is a 75 μm×1.2 cm×55 cm stainless steel (SUS304) (approximately the same weight as the copper foil).

In the magnetic sensitivity test, the test piece 1 obtained above is placed on a support stand 3 with a radius of curvature of approximately 0.25 cm, as shown in FIG. It was visually judged whether the test piece 1 moved by approaching it from both the direction and the perpendicular direction (magnetic sensitivity test I). When the test piece moved, it was evaluated as X, when it moved slightly, it was evaluated as △, and when it did not move, it was evaluated as ◎. The results are shown in Table 1.

In addition, the magnet 5 is made into a bar shape by stacking five 3000 Gauss in series (BH)max=22NG・Oe1 outer diameter 6φ×height 5mm.After removing the magnet 5, the magnetic needle is To the end of the test piece 1, which is approached by
bring them closer. Then, it was visually determined whether the magnetic needle could swing due to residual magnetism (Magnetic Sensitivity Test I+).If the magnetic needle swings, it is evaluated as ×1 if it does not swing. The results are shown in Table 81.

Regardless of whether this amorphous N1-P alloy layer was formed from the plating bath for Examples or from the plating bath for Comparative Examples 1 to 7, the layer before heating was It showed non-magnetism.

Thereafter, each test piece was heated at 600° C. for 10 minutes, and the above magnetic sensitivity test I was repeated. Similarly, the results are shown in Table 1.

The amorphous N1-P alloy layer of the example exhibited non-magnetism both before and after heating, while the 4.5 comparative example after heating showed paramagnetism, and the remaining comparative examples all showed hardness. It showed magnetism.

Next, a 10 μm thick amorphous N1-P alloy layer was formed on both sides of a 20 μm x 5 cm x 5 cm copper foil using a matting bath containing the components shown in Examples 9 to 12 in Table 2. (Second invention).

Regarding this, in addition to the magnetic sensitivity test described above, the following corrosion resistance test was conducted before and after heating.

In this corrosion resistance test, the test piece 1 was immersed in concentrated hydrochloric acid or concentrated nitric acid, and whether or not the test piece 1 disappeared was visually determined.

The time of disappearance is shown in Table 2. Note that 1 in the table indicates that the N1-P alloy does not disappear even after the time specified in the table has passed.

From the results in Table 2, it can be seen that Examples 8 to 11 exhibit suitable corrosion resistance.

Study examples A to G shown in Table 3 are not included in the present invention, although they were manufactured using a different plating bath from that described in the conventional publication (Japanese Unexamined Patent Publication No. 60-248882). First, it exhibited nonmagnetic properties before heating. Therefore, it is presumed that the N1-P alloys of Study Examples A to G are amorphous.

The plating conditions are the same as in Table 1.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the method of magnetic sensitivity test I. l... test piece, 5...Magnet. Patent applicant

Claims (1)

[Claims] (1) A plating bath that maintains a non-magnetic state even after heating at 600°C and contains the following components (a) or (b),
Among the complexing agents, the citric acid component is contained in a molar ratio of 1:8.0 to 1:10.0 (nickel ion: C_6H_5O_7) to nickel ions, or other complexes in an equivalent amount Amorphous Ni-P alloy manufactured by electroless plating using an agent containing: (a) Nickel ion Reducing agent for nickel ions Complexing agent for nickel ions pH adjusting agent Secondary phosphorus precipitation Accelerator. (a) Nickel ion Reducing agent for nickel ions Complexing agent for nickel ions pH adjuster Primary phosphorus precipitation promoter and second phosphorus precipitation promoter (2) 60
It maintains its non-magnetic state even after heating at 0℃, has corrosion resistance against nitric acid (69.8%), and contains the following ingredients (
A plating bath containing a) or (b), wherein the citric acid component in the complexing agent is in a molar ratio of 1:8.0 to 1:10.0 (nickel ion: C_6H
_5O_7) or a corresponding amount of other complexing agents, as well as group IVa or V of the Periodic Table of the Elements.
Group Ia metal has a molar ratio of 1 to nickel ion.
: Amorphous Ni-P alloy produced by electroless plating using 0.15 (nickel ions: the metal) or more dissolved; (a) Nickel ions Reducing agent for nickel ions Nickel ions Complexing agent pH adjuster secondary phosphorus precipitation promoter. (a) Nickel ion Nickel ion reducing agent Nickel ion complexing agent pH adjuster Primary phosphorus precipitation promoter and secondary phosphorus precipitation promoter