TW201718896A - Porous nickel thin film and manufacturing method thereof - Google Patents

Abstract

Provided is a porous nickel thin film having a flexibility value of no more than 15.0 N/mm.

Description

Porous nickel film and method of producing the same

The present invention relates to a porous nickel film and a method of producing the same.

Nickel films are expected to be used in many fields. For example, Japanese Patent No. 4411409 (Patent Document 1) discloses that a porous nickel plating film is used as a support for a hydrogen permeable metal film. Here, the nickel film is required to have softness.

[Previous Technical Literature] [Patent Literature]

Japanese Patent No. 4411409

An object of the present invention is to provide a nickel film having excellent softness and a method for producing the same.

The inventors of the present invention have found that a porous nickel film obtained by a specific method is particularly excellent in extremely high softness compared to a nickel film obtained by a conventional method. That is, the present invention includes the following matters.

[1] A porous nickel film characterized by having a soft value of 15.0 N/mm or less, and the soft value is a value measured by a method of supporting a jig by a test object to form a nickel film closed shape. a step of supporting the periphery of the nickel film in the unsupported region; and for the nickel film, one end of the jig is vertically inserted into the unsupported region, and the force applied to the jig and the change of the abutting jig are measured. The step of the relationship between the digits; the force (N) subjected to the jig is divided by the value (N/mm) obtained by the amount of displacement (mm) of the jig as the calculation step of the soft value.

[2] The porous nickel thin film according to the above [1], wherein the film thickness is 0.1 to 100 μm.

[3] A method for using a porous nickel film, comprising the steps of forming a nickel plating film on a conductive substrate using an electrolytic nickel plating bath containing a nickel salt and a surfactant; and burning the nickel A step of heat-treating the nickel plating film by using a surfactant contained in the plating film.

[4] The method according to the above [3], wherein the porous nickel film has a soft value of 15.0 N/mm or less. The softness value is a value measured by a method of supporting a jig by forming a non-supporting region of a nickel film closed shape by supporting a jig, and supporting all the periphery of the nickel film; Placing one end of the jig into the unsupported area vertically, and measuring the relationship between the force applied to the jig and the displacement amount of the abutting jig; the force (N) received by the jig is divided by the push The value (N/mm) obtained by the amount of deformation of the jig (mm) is used as a calculation step of the aforementioned soft value.

[5] The method according to the above [3] or [4] wherein the surfactant is a negative ion surfactant.

[6] The method according to the above [5], wherein the negative ion surfactant comprises a polyoxyalkylene alkyl ether sulfate, a polyoxyalkylene alkyl ether carbonate, and an alkyl group. a compound of the group consisting of besylate.

[7] The method according to any one of [3] to [6] wherein the step of forming the nickel plating film includes a step of performing pulse plating.

[8] The method according to any one of the above [3], wherein the conductive substrate is a Ti substrate, a Cu substrate, a SUS substrate, a glass that imparts conductivity, or imparts conductivity. Resin.

[9] The method according to any one of [3] to [8], further comprising the step of removing the porous nickel thin film from the conductive substrate.

According to the present invention, a nickel film excellent in softness and a method for producing the same can be provided.

1‧‧‧Electrically conductive substrate

2‧‧‧ Nickel plating film

3‧‧‧ Nickel film

4‧‧‧ holes

10‧‧‧Evaluation device

11‧‧‧ pedestal

12‧‧‧Measurement support fixture

12-1‧‧‧ Maintaining materials

12-2‧‧‧ Maintaining materials

13‧‧‧Admitted to the Fixture Support Department

14‧‧‧Entering fixtures

15‧‧‧Drive mechanism

17‧‧‧ openings

18‧‧‧Measurement device

18-1‧‧‧Weighing sensor

18-2‧‧‧Encoder

19-1‧‧‧Thread

19-2‧‧‧Thread

Fig. 1A is a cross-sectional view schematically showing a method of producing a porous nickel film.

Fig. 1B is a cross-sectional view schematically showing a method of producing a porous nickel film.

Fig. 1C is a cross-sectional view schematically showing a method of producing a porous nickel film.

Fig. 1D is a cross-sectional view schematically showing a method of producing a porous nickel film.

Fig. 2 is an external view showing an evaluation apparatus.

Fig. 3 is a schematic view showing an evaluation apparatus.

Fig. 4 is a cross-sectional view schematically showing a pair of holding members.

Fig. 5 is a schematic view showing an example of a jig.

Fig. 6 is a schematic view showing a method of evaluating softness.

Fig. 7 is a graph showing the results of measurement of softness.

Fig. 8 is a graph showing the calculation result of the soft value.

Hereinafter, embodiments of the present invention will be described.

1A to 1D are cross-sectional views schematically showing a method of producing a porous nickel film in the present embodiment.

First, as shown in FIG. 1A, a conductive substrate 1 is prepared.

Next, as shown in FIG. 1B, a nickel plating film 2 is formed on the conductive substrate 1. The nickel plating film 2 is formed using an electrolytic nickel plating bath containing a nickel salt and a surfactant. At this time, due to electrolytic nickel The plating bath contains a surfactant, and the formed nickel plating film 2 contains a surfactant.

Next, as shown in FIG. 1C, the nickel plating film 2 is subjected to heat treatment. The surfactant contained in the nickel plating film 2 can be burned and removed by applying heat treatment. As a result, in the nickel plating film 2, the pores 4 penetrating in the film thickness direction are formed, and the porous nickel film 3 is obtained.

When the nickel thin film 3 is used as a single film, as shown in FIG. 1D, the nickel thin film 3 is peeled off from the conductive substrate 1. In this case, in order to peel off the nickel thin film 3, the conductive base material 1 may be used in advance with a substrate having low adhesion to the nickel thin film 3. Examples of such a substrate include a metal substrate such as a Ti substrate, a Cu substrate, and a SUS substrate, and a glass or resin material that imparts conductivity. Further, in order to remove the heat treatment of the surfactant, the nickel thin film 3 may be peeled off from the conductive substrate 1 and then applied.

On the other hand, the nickel thin film 3 is not necessarily peeled off from the conductive substrate 1. The laminated substrate of the conductive substrate 1 and the nickel thin film 3 may be used as a final use without being separated from the conductive substrate 1 for the purpose of use.

When the above-described production method is used, a porous nickel film 3 excellent in softness can be obtained. Specifically, by using the above-described production method, the soft nickel film 3 can have a softness value of 15.0 N/mm or less, preferably 10.0 N/mm or less, and more preferably 1.0 to 10.0 N. /mm, especially good 3.0~8.0N/mm. The porous nickel film 3 having such a soft value is a novel metal film obtainable by the production method of the present invention, and has excellent softness and can be used for various purposes.

In the present specification, the "softness value" can be determined by a method for evaluating a porous nickel film to be described later and a method described in the examples.

Further, the porous nickel film 3 obtained in the present embodiment is also excellent in heat resistance. Calender The nickel film produced by the method is oxidized at a high temperature and may not be able to maintain its shape. On the other hand, the porous nickel thin film 3 obtained in the present embodiment can maintain its shape even when heated at a high temperature.

The film thickness of the nickel thin film 3 obtained in the present embodiment is preferably 0.1 μm to 100 μm, more preferably 1 μm to 10 μm, and particularly preferably 2 μm to 8 μm. When the film thickness is too large, the porosity becomes difficult, the processing difficulty increases, and the production cost tends to increase. On the other hand, if the film thickness is too small, the strength tends to be insufficient.

The use of the nickel film 3 obtained in the present embodiment is not particularly limited, and is, for example, used for a high performance catalyst film; a high-functional filter; a base film for coating, coating, and plating; at a high temperature The functional film and the exothermic film to be used; and the surface film of the sliding member.

When used as a high-performance catalyst film, it can disperse and support catalyst particles such as Pt and Pd particles directly or in the pores of the nickel film 3. When used as a highly functional filter, a through hole formed in the nickel thin film 3 is used as a fluid flow path. The softness is important from the viewpoint of film life with respect to a high-performance catalyst film, a highly functional filter, etc., and the nickel film 3 of the present embodiment can satisfy such requirements.

Further, the nickel thin film 3 obtained in the present embodiment can be used for a functional film and a heat releasing film which are required to have heat resistance because they are not damaged in a high temperature environment.

Further, the nickel thin film 3 of the present embodiment has a high surface area due to the provision of voids. Therefore, when used as a base film for coating, coating, and plating, the physical adhesion between the nickel thin film 3 and the film formed thereon can be improved.

Further, when the nickel film 3 of the present embodiment is used as a surface film of a sliding member, the retention of the lubricating oil can be improved by providing the pores, and the life of the sliding member can be extended.

(plating bath and plating conditions)

Next, the electrolytic nickel plating bath and plating conditions used in the present embodiment will be described in detail. As described above, the plating bath used in the present embodiment contains an aqueous solution of a nickel salt and a surfactant.

Nickel salt acts as a source of nickel ions. The nickel salt is not particularly limited, and a compound selected from the group consisting of Nisulfonic acid Ni, Ni chloride Ni, Ni sulfate, and Ni citrate is preferably used. Among these, the nickel salt preferably contains amine sulfonic acid Ni. By using Nisulfonic acid sulfonic acid, a film having low internal stress and high flexibility can be obtained.

The concentration of the nickel salt in the plating bath is preferably from 100 g/L to 800 g/L. When the concentration of the nickel salt is too high, the saturated dissolved concentration of the surfactant decreases, and the porosity becomes difficult, and the flexibility is easily impaired. When the concentration of the nickel salt is too low, the critical current density is lowered due to the insufficient concentration of the metal salt, and hydrogen gas is easily generated during the formation of the film, and the conductive substrate 1 of the base layer absorbs hydrogen and is likely to be cracked. In addition, the Ni plating film tends to be rough and has many pinholes.

The surfactant contained in the plating bath is preferably an ionic surfactant. As the ionic surfactant, an anionic surfactant is preferably used.

Suitable examples of the anionic surfactant are selected from the group consisting of polyoxyalkylene alkyl ether sulfates, polyoxyalkylene alkyl ether carbonates, polyoxyalkylene alkyl ether sulfosuccinates. , polyoxyalkylene alkyl ether phosphate, polyoxyalkylene alkyl ether acetate, alkyl benzene sulfonate, higher alcohol sulfate, polyoxyalkylene styrenated phenyl ether sulfate, alkane Diphenyl ether sulfonate, dialkyl sulfosuccinate, alkyl sulfonate, alkyl alkane sulfonate, alkyl naphthalene sulfonate, naphthalene sulfonate formaldehyde condensate, higher alcohol phosphate A compound of a group of ester salts, polyoxyalkylene styrenated phenyl ether phosphates, fatty acid rock bases, disproportionated rosinine, and sulfonated castor oil. Among these, selected from polyoxyalkylene alkyl ether sulfates, polyoxyalkylene alkyl ether carbonates, poly More preferred are oxyalkylene alkyl ether acetates and alkylbenzene sulfonate compounds.

Further, the polyoxyalkylene alkyl ether sulfate and the polyoxyalkylene alkyl ether carbonate are preferably those having an ethylene oxide compound represented by the following formula 1.

(Formula 1): R1-O-(CH ₂ CH ₂ O) _n -X

Further, in the formula 1, R1 represents an alkyl group, preferably an alkyl group having 10 to 16 carbon atoms, more preferably 12 to 14 carbon atoms. X represents a sulfate or carbonate. n is 1~20, and better is 2~12.

Further, the alkylbenzenesulfonate is preferably a compound having an alkyl group having 8 to 16 carbon atoms, more preferably a dodecylbenzenesulfonate.

The counter ion to be used for the salt of the negative ion surfactant may, for example, be an alkali metal salt such as a sodium salt or a calcium salt, an alkaline earth metal salt, an ammonium salt or an alkanolamine salt. Among them, an alkali metal salt is preferred. The sodium salt is better.

The concentration of the surfactant in the plating bath is preferably from 0.1 mL/L to 100 mL/L, more preferably from 1 mL/L to 50 mL/L, and particularly preferably from 5 mL/L to 30 mL/L. When the concentration of the surfactant is too high, plating deposition is inhibited, and it is difficult to obtain a dense film. On the other hand, when the concentration is too low, it becomes difficult to obtain porosity, and it is difficult to obtain desired softness.

Further additives such as a pH adjuster, a pH buffer, and a stress relieving agent may be further added to the plating bath. As the pH adjuster, for example, sulfuric acid, aminosulfonic acid, nickel hydroxide or the like can be used. A stress relieving agent can be used, for example, saccharin or the like.

The pH of the plating bath is preferably from 2.0 to 4.5. When the pH is too high, the critical current density is lowered, hydrogen gas is easily generated, and the conductive substrate 1 is easily sucked into hydrogen. In addition, Ni film capacity It is hard and hard. On the other hand, if the pH is too low, the decomposition of the plating bath component is easily promoted.

The bath temperature of the plating bath during plating is at 40 ° C ~ 65 ° C for home. If the bath temperature is too high, it becomes easy to decompose the bath components. On the other hand, if the bath temperature is too low, the surfactant is easily precipitated. In addition, Ni tends to precipitate abnormally.

Although electroplating can be performed by direct current electrolysis, it is better by pulse plating. When pulse plating is used, the surfactant is dispersed and adsorbed on the conductive substrate 1 in the initial stage of precipitation, and the co-deposition of the surfactant and nickel in the plating can be promoted.

When pulse plating is used, the average current density is preferably 1 A/dm ² to 20 A/dm ² . When the average current density is too high, hydrogen is excessively generated and the conductive substrate 1 of the base layer is affected. In addition, it may cause an abnormal precipitation of Ni. On the other hand, if the average current density is too low, it is difficult to make the porous, and it is difficult to obtain the desired softness. In addition, productivity is lowered.

The pulse current density is preferably ² A/dm ² to 20 A/dm ² . When the pulse current density is too high, hydrogen is excessively generated and the conductive substrate 1 of the base layer is affected. When the pulse current density is too low, it is difficult to perform porosity and productivity is lowered.

The ratio of the pulse application time ton to the pulse stop time toff (ton/toff) is preferably 0.1 to 10. If the ton/toff value is too large, the porosity is difficult, and it is difficult to obtain the desired softness. Moreover, if it is too low, it becomes difficult to make a porous, and it is difficult to obtain the desired softness.

The pulse frequency is preferably 0.1 to 1000 (Hz). If the pulse frequency is too large, the porosity is difficult, and it is difficult to obtain the desired softness. In addition, if it is too low, it is difficult to make it porous. It is difficult to obtain the desired softness.

(heat treatment conditions)

Next, the heat treatment conditions for the removal of the surfactant by combustion will be described. The heat treatment is carried out, for example, in a reducing gas atmosphere such as the atmosphere or hydrogen, or in an inert gas atmosphere such as nitrogen or argon, to carry out the conditions for burning and removing the surfactant.

Specifically, the heat treatment temperature is, for example, 350 ° C to 900 ° C. In addition, the heating time is, for example, 10 minutes to 120 minutes. If the heating temperature is too high, the cost at the time of mass production processing tends to increase. Further, an interdiffusion layer is easily formed between the conductive substrate 1 of the base layer and the nickel plating film 2, and the softness is easily impaired. On the other hand, when the heat treatment temperature is too low, it is less likely to be porous, and the desired softness cannot be obtained. Further, when the heating time is too long, the interdiffusion layer is easily formed. Further, if the heating time is too short, it is difficult to cause porosity and the softness is impaired.

(Evaluation method of porous nickel film)

As described above, the nickel thin film 3 produced by the method of the present embodiment has excellent softness characteristics. Specifically, a porous nickel film 3 having a "soft value" of 15.0 N/mm or less can be obtained. Here, the "soft value" is a value obtained by the evaluation method described below.

Fig. 2 is an external view showing an evaluation apparatus 10 for an evaluation method of a soft value. In addition, FIG. 3 is a schematic diagram showing the evaluation apparatus 10. As shown in FIGS. 2 and 3 , the evaluation device 10 includes a main body portion 16 , a pedestal 11 , a push jig support portion 13 , a measurement device 18 , a push jig 14 , a test object support jig 12 , and a drive mechanism 15 . Further, the jig 14 and the test fixture 12 are detachable, and are only drawn in FIG. 3, and are not drawn in FIG.

The pedestal 11 is supported by the body portion 16 in order to support the test object supporting jig 12 .

The test object supporting jig 12 is provided to support the nickel film 3 of the test object (refer to FIG. 3). The test object supporting fixture 12 is attached to the pedestal 11 and can be installed by itself. Fig. 4 is a cross-sectional view schematically showing the test object supporting jig 12. The object to be tested supports the jig 12 and has a pair of holding members (12-1 and 12-2). The opening portion 17 is provided on one side of the holding member 12-1. The other holding member 12-2 is provided with a recess 16 at a corresponding position of the opening 17. The opening 17 and the recess 16 each have a circular shape with a predetermined diameter a. Further, the holding member 12-2 may be provided with an opening instead of the recessed portion 16. Further, in each of the holding members (12-1, 12-2), the threads (19-1 and 19-2) are provided to hold the nickel film 3, and the holding member 12-1 can be screwed to the holding member 12-2. . The central portion of the nickel film 3, that is, the region corresponding to the opening 17, does not contact the test object supporting jig 12. That is, the test object supporting fixture 12 is configured to support the entire circumference of the nickel film 3, and the central portion of the nickel film 3 forms a closed shape unsupported region corresponding to the opening 17.

The jig support portion 13 (see FIGS. 2 and 3) is attached to support the jig 14 . The jig support portion 13 is moved in the vertical direction with respect to the nickel film 3, and is attached to the main body portion 16.

The drive mechanism 15 is attached to the main body portion 16 and has a function of moving the jig support portion 13. The drive mechanism 15, such as a motor.

The jig is placed in a 14-bar shape. The jig 14 is pushed over the nickel film 3 so as to extend in the vertical direction with respect to the nickel film 3, and is supported by the jig support portion 13. Further, the jig 14 is placed such that one end (lower end) thereof is disposed directly above the center of the opening 17 provided in the holding member 12-1.

Fig. 5 is a schematic view showing an example of the pushing jig 14. Better, as shown in Figure 5. As shown, one end of the jig 14 has a shape corresponding to a portion of the ball of a predetermined diameter b.

The measuring device 18 (see FIG. 3) has a function of detecting the amount of displacement of the jig 14 when a force is applied to the jig. Specifically, the measuring device 18 includes a weighing sensor 18-1 and an encoder 18-2. The weighing sensor 18-1 is provided between the push jig support portion 13 and the urging jig 14 and has a function of detecting the force applied to the plunging jig 14. The encoder 18-2 is connected to the drive mechanism 15 and detects the amount of displacement of the jig support portion 13, that is, the amount of displacement of the jig 14.

Next, the evaluation method of the present invention will be described.

First, the test piece supporting the nickel film 3 by the test object supporting fixture 12 is attached to the pedestal 11. Further, the push jig 14 is attached to the jig support portion 13 via the weighing sensor 18-1.

Then, the driving fixture 15 moves the pressing jig support portion 13 downward (on the side of the object supporting fixture 12). Thereby, as shown in Fig. 6, one end of the jig 14 is pushed, and the nickel film 3 is vertically pushed from the center of the opening 17. The jig 14 is pushed in and pushed in until the nickel film 3 is worn. At this time, the force applied to the jig 14 and the amount of displacement of the jig 14 are measured by the measuring device 18. As a result of the measurement, the data indicating the relationship between the force applied to the jig 14 and the displacement amount of the jig 14 is stored in a computer (not shown) or the like.

Based on the obtained data, the soft value of the nickel film 3 was calculated. Here, the "soft value" in the present specification is a value represented by a value (N/mm) obtained by dividing a force (N) applied to the jig by a displacement amount (mm) of the jig. The smaller the value, the softer the expression. Specifically, the displacement amount is the horizontal axis, and the force (test force) received by the jig 14 is plotted on the vertical axis, and a linear good range is obtained (for example, the correlation coefficient R ² obtained by linear approximation exceeds The slope of the area of 0.9 can be used to calculate the soft value.

According to the above evaluation method, the softness of the nickel film 3 having a film thickness of 0.1 to 100 μm can be appropriately evaluated.

Further, the diameter a (see FIG. 4) of the opening 17 provided in the holding member 12-1 is preferably 9 mm to 14 mm, more preferably 10 mm to 13 mm, and particularly preferably 11 mm to 12 mm. When the diameter a is too small, a sufficient amount of displacement cannot be obtained for the test force; when it is too large, a large sample area is required.

The shape of one end of the jig 14 (refer to FIG. 5) is not particularly limited, and as described above, it is preferable that the shape of one of the balls having the diameter b is preferable. For example, in the case where the shape of one end of the jig 14 is polygonal, the portion of the jig 14 is attached to the test piece at an angular portion, and the test force is concentrated on the corner portion, and the test piece is easily torn on the way. As a result, in the test force-displacement amount chart, it is difficult to secure a region having a high linear relationship. Further, when the shape of one end of the jig 14 is a flat plate shape such as a flat plate shape, the end portion of the flat plate shape deforms the test piece at an acute angle, and it is difficult to obtain a high linear relationship. On the other hand, in the case where the shape of one end of the jig 14 is a shape having a portion corresponding to the ball, the effect of pushing the test piece into the face can be obtained. In detail, when the push-in jig 14 is pushed in, the test piece is smoothly stretched while forming an obtuse angle, and a higher linear relationship is easily obtained.

Further, the diameter b is preferably 5 mm to 10 mm, more preferably 6 mm to 9 mm, and particularly preferably 7 mm to 8 mm. When the diameter b is too small, the test piece is pressed at a point, and the test piece is easily broken quickly. On the other hand, when the diameter b is too large, the object supporting fixture 12 also needs to be enlarged, and the required sample area is also increased.

Further, the ratio of the diameter b of the diameter a of the opening 17 (diameter b / diameter a), It is preferably 0.3 to 0.9, more preferably 0.4 to 0.8, and particularly preferably 0.5 to 0.7. If the ratio of the diameter b to the diameter a is in such a range, a high linear relationship is easily obtained.

The pushing speed of the jig 14 is preferably from 0.1 mm/min to 10.0 mm/min, more preferably from 0.5 mm/min to 5.0 mm/min, and from 1.0 mm/min to 2.0 mm/ Min is especially good. If the pushing speed is too slow, it takes a long time to test. On the other hand, when the pushing speed is too fast, the test piece is likely to break the film, and it is easy to break the film in a state where the high linear region cannot be sufficiently ensured.

Next, the embodiments will be described in order to explain the present invention in more detail.

[Example 1]

As the conductive substrate 1 of the base layer, a SUS substrate was prepared. In the conductive substrate 1, a nickel plating film 2 is formed by an electroplating method. At this time, as the plating bath, an aqueous solution containing 600 g/L of amine sulfonic acid Ni, 10 g/L of chlorinated nitrogen, 40 g/L of boric acid, and 10 ml/L of an anionic surfactant (sodium dodecylbenzenesulfonate) was used. The plating bath had a pH of 3.5 and a bath temperature of 60 °C. Electroplating is performed by pulse plating. Pulse plating was carried out under the conditions of an average current density of 5.9 A/dm ² and a ratio of (ton/toff) of 1.4. Next, the nickel plating film 2 is peeled off from the conductive substrate 1. Further, the nickel plating film 2 was heat-treated at 500 ° C for 60 minutes in the air to obtain a nickel thin film 3 of Example 1. The thickness of the obtained nickel thin film 3 was 5 μm.

[Example 2]

The nickel film 3 of Example 2 was obtained in the same manner as in Example 1. However, the heat treatment time was 120 minutes.

[Comparative Example 1]

The nickel film of Comparative Example 1 was obtained in the same manner as in Example 1. However, no heat treatment is performed.

[Comparative Example 2]

A nickel film of Comparative Example 2 was obtained in the same manner as in Example 1. However, no heat treatment is performed. Further, the electrolytic bath used a solution of dissolving sulfuric acid Ni 350 g/L, chlorinated Ni 60 g/L, and trisodium citrate 30 g/L in water (excluding a surfactant). The plating bath had a pH of 4.6 and a bath temperature of 60 °C. The plating conditions were carried out under the conditions of a current of 0.1 A.

[Comparative Example 3]

The nickel film of Comparative Example 3 was prepared by a calendering method of a nickel film having a thickness of 10 μm.

[Comparative Example 4]

The metal film of Comparative Example 4 was a Cu film having a thickness of 10 μm which was produced by a rolling method.

[Comparative Example 5]

The metal film of Comparative Example 5 was prepared by a calendering method of an Al film having a thickness of 10 μm.

[Comparative Example 6]

The nickel film of Comparative Example 2 was subjected to heat treatment under the same conditions as in Example 1 in an attempt to obtain a nickel film of Comparative Example 6. However, the nickel film of Comparative Example 2 after the heat treatment became weak due to oxidation, and the shape could not be maintained.

Next, the softness of the nickel film or the metal foil obtained by Examples 1 to 2 and Comparative Examples 1 to 5 was evaluated. Specifically, the relationship between the test force and the displacement amount was measured using the evaluation device 10 described in FIGS. 2 to 6.

Specifically, the test piece was cut into a circle having a diameter of 20 mm. Next, use the opening 17 and The recessed portion 16 has a diameter of 12 mm, holds the test piece against the holding members (12-1 and 12-2), and fixes the pedestal 11. Further, the jig 14 is inserted into a jig having a shape corresponding to one of the balls having a diameter of 7 mm at one end, and is attached to the jig support portion 13. By pushing the jig support portion 13 toward the pair of grip members 12 at a speed of 1 mm/min, one end of the jig 14 is brought into contact with the test piece from the center of the opening 17. Further, the jig 14 is pushed in until the test piece is pierced, and the relationship between the amount of displacement of the jig 14 and the test force (the force applied to the jig 14) is measured by the measuring device 18.

Fig. 7 is a graph showing the results of the measurement. In Fig. 7, the correspondence between the respective lines and the first to second embodiments and the comparative examples 1 to 5 is as follows.

Example 1: Line "1"

Example 2: Line "2"

Comparative Example 1: Line "3"

Comparative Example 2: Line "4"

Comparative Example 3: Line "5"

Comparative Example 4: Line "6"

Comparative Example 5: Line "7"

In each of the graphs of Fig. 7, the portion where the test force is drastically reduced corresponds to the point at which the test piece is broken (hereinafter referred to as a breaking point). In any of Examples 1 to 2 and Comparative Examples 1 to 5, the relationship between the linearly high displacement amount and the test force was obtained from the origin to the break point region. This indicates that the evaluation method of the present invention appropriately reflects the softness of the test piece.

As shown in Fig. 7, in the nickel film 3 of Examples 1 and 2, the amount of displacement of the test piece before breaking was larger than that of the nickel film or the metal foil of Comparative Examples 1 to 5. Further, Examples 1 and 2 are compared compared In Examples 1 to 5, the area surrounded by the origin, the breaking point, and the point on the X-axis corresponding to the breaking point, that is, the amount of action on the elongation is large. This shows that Examples 1 and 2 are easily stretched and softer than Comparative Examples 1 to 5, and have high mechanical strength.

Fig. 8 is a graph showing the calculation result of "soft value". Further, in the graph shown in Fig. 7, the "soft value" is obtained by finding a range in which the linearity is good (the correlation coefficient R ^{2 of the} linear approximation is 0.9), and the slope is calculated. As shown in Fig. 8, in Examples 1 and 2, the "softness value" was smaller than that of Comparative Examples 1 and 2. That is, it can be understood that the nickel film 3 which is easy to elongate and soft can be obtained by electroplating using a plating bath containing a surfactant and removing the surfactant by heat treatment. Further, it can be understood that the nickel film 3 of Examples 1 and 2 has a smaller softness value than the metal films of Comparative Examples 3 and 4, and is more easily elongated and softer than the nickel film and the Cu film obtained by the calendering method. .

Further, the soft values of Examples 1 and 2 were larger than those of Comparative Example 5. As shown in Fig. 7, Comparative Example 5 pierced the test piece with a minimum amount of displacement compared with Examples 1 and 2. That is, it can be understood that the nickel thin film 3 of Examples 1 and 2 has excellent mechanical strength superior to that of the Al film obtained by the calendering method.

Further, the nickel plating film of Comparative Example 6 could not maintain its shape after the heat treatment, and in Examples 1 and 2, the heat treatment was carried out, in addition to maintaining the shape and improving the softness. From this point of view, the results of Examples 1 and 2 can be said to be unpredictable results.

3‧‧‧ Nickel film

4‧‧‧ holes

Claims (9)

A porous nickel film characterized by having a soft nickel film having a softness value of 15.0 N/mm or less, and the softness value is a value measured by a method of supporting a jig by a test object to form a nickel film. a non-supporting region of the shape to support all the periphery of the nickel film; for the nickel film, one end of the jig is vertically inserted into the unsupported region, and the force applied to the jig and the abutting jig are measured The step of the relationship of the displacement amount; the force (N) subjected to the pressing of the jig divided by the value (N/mm) obtained by the displacement amount (mm) of the jig is used as the calculation step of the aforementioned soft value. The porous nickel thin film according to the first aspect of the invention, wherein the film thickness is 0.1 to 100 μm. A method for producing a porous nickel thin film, comprising the steps of forming a nickel plating film on a conductive substrate using an electrolytic nickel plating bath containing a nickel salt and a surfactant; and burning and removing the nickel plating a surfactant contained in the film, and a step of heat-treating the nickel plating film. The method of claim 3, wherein the porous nickel film has a softness value of 15.0 N/mm or less, and the soft value is a value measured by a method comprising the following steps: Supporting the jig to form an unsupported area in which the nickel film is closed, while supporting the aforementioned a step of all the periphery of the nickel film; and stepping the one end of the jig into the unsupported region vertically, and measuring the relationship between the force received by the pressing jig and the displacement amount of the abutting jig; The force (N) subjected to the jig is divided by the value (N/mm) obtained by the amount of displacement of the jig (mm) as a calculation step of the aforementioned soft value. The method of claim 3, wherein the surfactant comprises an anionic surfactant. The method of claim 5, wherein the negative ion surfactant comprises a polyoxyalkylene alkyl ether sulfate, a polyoxyalkylene alkyl ether carbonate, and an alkylbenzene. a group of compounds of sulfonates. The method according to any one of claims 3 to 6, wherein the step of forming the nickel plating film comprises the step of performing pulse plating. The method according to any one of claims 3 to 7, wherein the conductive substrate is a Ti substrate, a Cu substrate, a SUS substrate, a glass that imparts conductivity, or a resin that imparts conductivity. . The method according to any one of claims 3 to 8, further comprising the step of peeling the porous nickel thin film from the conductive substrate.