JP2003231978A - Brass-plated material superior in adhesiveness to rubber, and composite thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a brass-plated material which effectively prevents an adhering interface from embrittling with time, to develop the satisfactory stable adhesiveness over time, while adequately keeping the adhesion to a rubber obtained at the time of vulcanization/adhesion and product finishing, and to provide a composite thereof. <P>SOLUTION: The brass-plated material has the brass-plated layer formed on the surface of the base metal, and an oxide film of 50 nm or thinner containing zinc and copper formed on the surface of the brass-plated layer, wherein the oxide film of 10 nm or thicker, in a cross-section observation view transverse to the brass-plated surface, has 500 nm or shorter of a continuous length A (nm) on the plated surface, has 5-60% of a rate R<SB>1</SB>(%) of a total of the continuous length A (nm) to the total length of the observation view on the plated surface, and further satisfies the relationship of A (nm)≤10×R<SB>1</SB>(%). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a tire, a hose,
The present invention relates to steel strands (steel cords, bead wires, etc.) used for reinforcement of industrial belts, brass plating materials used as materials to be bonded to rubber linings and rubber rolls, and composites thereof, especially rubber and The present invention relates to a brass-plated material having excellent adhesiveness, and a composite in which rubber is bonded to the surface of such brass-plated material. The brass plating material targeted by the present invention includes various metal materials such as steel wire, steel plate, and steel for machine structure as a base material to which brass plating is applied. The case of using a line will be mainly described.

[0002]

2. Description of the Related Art In various applications as described above, from the viewpoint of improving the adhesiveness between a metal material as a base material and rubber, wet brass plating is applied to the surface of the base material to obtain a brass plating material. The technique of joining rubber and rubber by vulcanization is widely applied. As such technology,
A typical example is joining a brass-plated steel wire and rubber in an automobile tire.

The brass-plated steel wire is obtained by forming a brass-plated layer on the surface of a wire material before wire drawing and drawing the brass-plated layer. In addition, the brass plating layer on the steel wire is formed by first forming a copper plating layer on the wire material by wet electroplating, then forming a wet electrogalvanizing layer on top of it, and then heating to alloy both metals. It is generally a brass plating layer.

Since the above-mentioned automobile tires are used under severe conditions, it goes without saying that the rubber-steel wire has good adhesiveness (initial adhesiveness) when the product is finished.
It is also necessary to exhibit and maintain excellent rubber adhesiveness during subsequent use. That is, while the tire is in use, the temperature of the tire rises, and chlorine ions, which is a corrosion factor caused by moisture, snow-melting salt, etc. from external damage, etc., penetrate into the interior, which is the worst that hinders the adhesion between brass plating and rubber. Will be exposed to the environment.

In recent years, from the viewpoint of recycling, large tires used for trucks, buses, etc.
After the first life, it is often used up to the second and even the third by replacing the tire tread part,
Increasing the life of tires and long-term stabilization of rubber adhesion (adhesion with time) during use are becoming more and more desirable.

Various techniques have been proposed up to now as a technique for improving the rubber adhesiveness when a tire is used. For example, in Japanese Patent Laid-Open No. 11-113233, cobalt is contained in brass plating and the content thereof is There has been proposed a technique for improving the adhesiveness between the rubber and the brass plating material by providing a concentration gradient that increases from the plating surface side toward the inside. In addition, JP-A-11-9
No. 3086 discloses a technique in which the copper content on the brass plating surface is made lower than that in the inside and a rubber coating layer containing a cobalt organic acid is provided on the brass plating surface to improve the adhesiveness. Further, Japanese Patent No. 3096159 proposes a technique for improving the adhesiveness to rubber by containing phosphorus (P) on the brass plating surface and controlling the roughness of the interface between the brass plating and the substrate to be plated. Has been done.

The development of these techniques has significantly improved the adhesion between the brass-plated material and the rubber during use. However, the inclusion of cobalt or phosphorus tends to delay the vulcanization adhesion between the rubber and the brass plating on the one hand, or to hinder the rubber adhesion at the time of product finishing. Further, it is difficult to control the provision of a gradient in the plating composition in a normal plating process. Moreover,
There is a problem that the desired effect cannot be obtained only by controlling the roughness of the interface between the brass plating and the base material to be plated.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object thereof is to maintain good rubber adhesiveness during vulcanization adhesion and finished product, To provide a brass-plated material capable of effectively preventing brittleness of an adhesive surface with the passage of time and exhibiting good adhesiveness over time, and a composite obtained by bonding rubber to the brass-plated material to form a composite. It is in.

[0009]

The brass-plated material of the present invention that has achieved the above object is a brass-plated material in which the surface of a base material is plated with brass. An oxide film containing zinc and zinc and having a thickness of 50 nm or less is formed, and the oxide film having a thickness of 10 nm or more has a continuous length A (nm) on the plating surface in a cross-section observation field perpendicular to the brass plating surface. Fifty
0 nm or less, and the total continuous length A (nm) occupies 5 to 60% of the ratio R ₁ (%) to the total length of the observation field of the plating surface, and further, A (nm) ≦ 10 × R ₁ (% )
The point is that the relationship is satisfied.

In this brass-plated material, in the surface curve of 1 μm in length observed in the right-angled cross-sectional field, the area in which the difference between the highest elevation point and the lowest elevation point is within 50 nm is the observation field of the plated surface. It preferably accounts for 70% or more of the entire length.

On the other hand, the composite of the present invention capable of achieving the above object is a composite in which rubber is vulcanized and bonded to the surface of a brass-plated material, and the brass-plated surface and the rubber in the composite. In the vicinity of the interface of, a reaction layer containing copper, zinc and sulfur is formed in the rubber,
An oxide film containing copper and zinc and having a thickness of 50 nm or less is formed on the brass plating side, and the oxide film having a thickness of 10 nm or more is formed on the interface adjacent to the reaction layer in the cross-sectional observation visual field perpendicular to the brass plating surface. The continuous length B (nm) is 1000 nm or less, and the total of the continuous length B (nm) occupies 50 to 90% in the ratio R ₂ (%) to the total observation field of the plating surface. The point is the gist.

Further, in this composite, the oxide film observed in the right-angled cross-sectional view has the highest elevation point and the lowest elevation point in the interface curve having a length of 1 μm on the interface adjacent to the reaction layer. It is preferable that the region having a difference of 50 nm or less occupies 70% or more of the entire length of the observation visual field of the plating surface.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The basic principle of improving the adhesiveness with rubber in a brass plating material is considered as follows. That is, there is an oxide film on the brass plating surface, which prevents dezincification corrosion and also prevents copper or zinc from diffusing from the inside of the brass plating to the surface. It is considered that the adhesive property with time is improved. However, if the oxide film on the brass-plated surface becomes too thick, vulcanization adhesion is hindered, and therefore the oxide film tends to be formed as thin as possible. Further, although the influence of the composition of the oxide film on the adhesiveness has been investigated, no attempt has been made to control the distribution of the oxide film to improve the adhesiveness.

The present inventors have paid attention to the oxide film as described above, and have made repeated studies on the influence of the distribution state of the oxide film on the initial adhesiveness and aging adhesiveness of rubber. As a result, the initial adhesion of the brass plating material to the rubber is maintained well by controlling the distribution state of the oxide film appropriately, and in particular by giving a shade to the film thickness and distributing it in a sea-island shape on the brass plating surface. The present invention has been completed by discovering that the adhesiveness with time when used as a product can be remarkably improved.

The structure, operation and effect of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory view schematically showing a surface layer cross section of a brass plating material of the present invention,
In the figure, 1 is a base material plated with brass, 2 is a brass plating layer, and 3a to 3f are oxide films. Incidentally, FIG.
(A) to (d) show arbitrary four visual field equivalents when a cross section perpendicular to the plated surface is observed by the method described later, but in actual measurement, an arbitrary 10
The field of view was observed.

The oxide films 3a to 3f formed on the surface of the brass plating layer 2 contain copper and zinc, and contain zinc / zinc.
It is a portion where the composition ratio of copper is 1.0 or more. Further, the oxide films 3a to 3f are all formed to have a thickness of 50 nm or less. Among them, the oxide film portion to be measured in the present invention is a portion having a thickness of 10 nm or more.
The elements and composition ratio in the oxide film can be measured by, for example, EDX analysis.

This oxide film has a continuous length A (nm) of 500 n on the plating surface in the visual field for observing the cross section at right angles.
it is necessary to hereinafter as m, and the continuous length A, of the oxide film 3a~3f ‥ 3 _x (10-field equivalent), the thickness of s husband in the region excluding the portions less than 10nm length a ₁ , a ₂ , a ₃ , a ₄ , a ₅ ... A _x, and in the brass plating material of the present invention, the continuous length A is 500 nm.
It is below.

In the present invention, the total continuous length A of the oxide film must account for 5 to 60% of the ratio R ₁ (%) to the entire length of the observation visual field of the plating surface, but this ratio R ₁ Is the length of one side of each field of view L ₁ , L ₂ , L ₃ , L ₄
‥ sum of _{L 10 (L 1 + L 2} + L 3 + L 4 ‥ + L 10) continuous length to _{a 1, a 2, a 3} , a 4, a 5 sum of ‥ a _x (a ₁ +
a ₂ + a ₃ + a ₄ + a ₅ + ... + ax _x [[(a ₁ + a ₂ +
_{a 3 + a 4 + a 5} + ‥ + a x) / (L 1 + L 2 + L 3 + L 4 ‥ +
L ₁₀ )] × 100 (%)].

In the brass-plated material of the present invention, the difference between the highest elevation point and the lowest elevation point (elevation difference) in the surface curve having a length of 1 μm observed in the right-angled cross-sectional view.
It is a preferable requirement that the region having a thickness of 50 nm or more occupy 70% or more of the entire length of the observation visual field of the plating surface (hereinafter, may be referred to as “occupancy rate”). This occupancy rate is, for example, one side length L ₁ , L ₂ , L ₃ , L _{4 of} each field of view.
When L _{10 is set} to 1 μm, the remaining sum (L ₁ + L ₃ + L ₄ +) excluding L ₂ having a level difference of more than 50 nm
+ L ₁₀ ) summation (L ₁ + L ₂ + L ₃ + L ₄ ... + L ₁₀ ).
To [[(L ₁ + L ₃ + L ₄ + ... + L ₁₀ ) / (L ₁
+ L ₂ + L ₃ + L ₄ ... + L ₁₀ )] × 100 (%)].

In the brass plating material having the above-mentioned surface texture, the oxide films 3a to 3f formed on the surface must all have a film thickness of 50 nm or less. If there is a portion where the thickness of this oxide film exceeds 50 nm,
This is because in vulcanization adhesion, formation of a reaction layer between rubber / brass plating (see FIG. 2 to be described later) is obstructed and adhesion with time is impaired. Further, the continuous length A of the oxide film needs to be 500 nm or less as described above. This continuous length A
Is more than 500 nm, a local reaction layer defective part (a part where the reaction layer is not formed) is generated in the vulcanization adhesion, and there is a concern that the initial adhesion may be deteriorated.

The present invention is intended for the portion where the thickness of the oxide film is 10 nm or more, but if the thickness is smaller than this, the effect of improving the temporal adhesiveness described later cannot be sufficiently observed. Therefore, as described above, the continuous lengths a ₁ , a ₂ , a ₃ , a ₄ , and a ₅ of the oxide film are the lengths in the region excluding the portion having a thickness of less than 10 nm (for example, the oxide film 3b). is there.

The above-mentioned ratio R ₁ of the oxide film on the brass-plated surface needs to be 5 to 60%, and this ratio R ₁
And the maximum length A are A (nm) ≦ 10 × R ₁ (%)
Need to satisfy the relationship. The ratio R ₁ is less than 5%, or if that does not satisfy the above relationship, in the aged adhesion, its improving effect can not be well recognized, the ratio R ₁
When it exceeds 60%, the reaction layer formation in vulcanization adhesion is hindered.

In the brass-plated material of the present invention, it is preferable that the occupancy of the region where the elevation difference on the surface curve is within 50 nm is 70% or more. This is because a step difference of more than 50 nm is likely to be a starting point for cracking of peeling during adhesion over time. Therefore, it is preferable to make the surface curve such a step as little as possible in order to improve the adhesion property over time. Is.

In the present invention, the method of forming the oxide film in the above-mentioned form on the brass plating surface is not particularly limited, and for example, vapor phase plating methods such as sputtering and ion plating, or anodic oxidation, etc. Chemical method, heat treatment in the atmosphere, etc. can be adopted. Further, as a means for controlling the distribution of the oxide film,
(A) changing the diameter of the wire forming the oxide film, (b) changing the area reduction ratio of the wire drawing, (c) changing the lubricity during wire drawing, (e) mechanically grinding the plated surface Yes, there are various means.

Rubber is vulcanized and adhered to the surface of the brass-plated material having the above-mentioned oxide film formed. At this time, sulfur diffused from the rubber side and copper diffused from the brass-plated side (partly). , Also containing zinc), a rubber / brass plating reaction layer containing copper and sulfur as a main component and partially containing zinc is formed on the brass plating surface or the oxide film surface. At this time, a new oxide film is formed on the interface between the reaction layer and the brass plating due to oxygen considered to be contained in the rubber.

Copper and zinc during brass plating are more likely to diffuse to the rubber side in regions where the oxide film is thinner, and newly formed oxide films are formed in regions where there is little or no initial oxide film. It is easy to be done. Further, in the region where the oxide film is initially formed, the film thickness tends to spread laterally rather than increase.

On the other hand, it is considered that a boundary remains between the oxide film previously formed on the brass plating surface and the oxide film newly formed, but the former is controlled to a predetermined film thickness, maximum length and distribution. Therefore, it is considered that the former oxide film acts as a wedge even after vulcanization and adhesion, and the density of the oxide film and the sea-island distribution are maintained. As a result, it is considered that the temporal adhesiveness is also improved.

It is not possible to elucidate all of the reasons why the density and sea-island distribution of the oxide film formed in advance improve the adhesiveness over time. However, cracks when adhesion peeling occurs are caused by oxidation. It is considered that the oxide propagates in the oxide film in the vicinity of the interface between the film and the brass plating, and it is considered that the non-uniform presence of the oxide film causes the propagation of cracks to be stopped midway.

FIG. 2 is an explanatory view schematically showing the interface cross section of a composite in which rubber is bonded to the surface of the brass plating material having the above-mentioned configuration. The structure shown in FIG. 2 is based on the assumption that rubber is bonded to the brass plating material shown in FIG. 1, and parts corresponding to those in FIG. 1 are designated by the same reference numerals. . However, oxide film 3a
3f are in a state in which their shapes have grown and become slightly larger than those in the state shown in FIG. 1, and in some cases the bonding of the oxide films (in FIG. 2, oxide films 3a and 3b shown in FIG. 1). ,
3c and 3d are combined to form one oxide film).

In the composite of the present invention, a reaction layer 4a containing copper, zinc and sulfur is formed in the rubber 4 in the vicinity of the rubber / brass plating interface, and a thickness of 50 nm containing copper and zinc is formed. The following oxide films 3a to 3f are formed on the brass plating 2 side. Oxide film 3a
3 to 3f indicate the portions containing copper and zinc as described above and having a zinc / copper composition ratio of 1.0 or more. Further, like the brass plating material, the oxide films 3a to 3f are required to have a film thickness of 50 nm or less. This is because if there is a portion where the film thickness of this oxide film exceeds 50 nm, the film thickness becomes excessively large, cracks are likely to occur, and the adhesiveness with time deteriorates.

In the composite of the present invention, the oxide film has a thickness of 1
The target is a portion of 0 nm or more. If the thickness is thinner than this, dezincification corrosion, the effect of preventing diffusion of copper and zinc from the plating side to the rubber side will be insufficient, and the density of the oxide film will also be insufficient, leading to crack propagation during adhesion peeling. This is because the preventive effect is not sufficiently observed and the adhesiveness with time deteriorates. Therefore, the continuous length B (b ₁ , b ₂ , b ₃ , b ₄ ) of the oxide film is the length of the portion excluding the portion having a thickness of less than 10 nm.

In the composite of the present invention, the above oxide film
3a to 3f are cross-sectional observation views at right angles to the brass-plated surface
Continuous length on the interface adjacent to the reaction layer 4a in the field
It is necessary that the thickness B be 1000 nm or less. This continuous length
Sa is the oxide films 3a + 3b, 3c + 3d, 3
e, 3f ... 3_xEach length b (corresponding to 10 fields of view)₁, B
₂, B₃, B_Four... b_yMeans that this continuous length B is 1000
If it exceeds nm, the crack propagation in the above-mentioned adhesion peeling will occur.
Insufficient prevention of sowing.

In the composite of the present invention, the oxide film 3a
～3F ‥ While 3 the sum of _x consecutive length B needs to occupy 50-90% at a ratio R ₂ (%) with respect to the observation field of view the entire length of the plating surface, the ratio R ₂ is less than 50%, dezincification Adhesion properties over time such as corrosion prevention and copper and zinc diffusion inhibition are not sufficiently observed, and when it exceeds 90%, crack propagation in adhesive peeling is insufficiently prevented.

The ratio R ₂ is the sum (L ₁ + L ₂ + L ₃ + L ₄₎ of the lengths L ₁ , L ₂ , L ₃ , L ₄ ... L ₁₀ of one side of each field of view.
‥ + length to _{L 10) b 1, b 2} , b 3, b 4 ratio of the sum of _{‥ b y (b 1 + b} 2 + b 3 + b 4 + ‥ + b y) [[(b 1 +
_{b 2 + b 3 + b 4} + ‥ + b y) / (L 1 + L 2 + L 3 + L 4 ‥ +
L ₁₀ )] × 100 (%)].

In the composite of the present invention, the brass
Observed in the right-angle cross-section observation field, as in the case of metal
The oxide film of 1 μm on the interface adjacent to the reaction layer.
The highest and lowest elevation points on the interface curve
The occupancy of the area where the difference (elevation difference) is 50 nm is 70% or less.
The above is preferable. As mentioned above, this is 50
A step difference of more than nm may cause peeling of the adhesive during aging.
It tends to be the starting point for cracks to separate, and
It is preferable to use a surface curve with as little difference as possible
Because. The occupancy rate is, for example, the length of one side of each field of view.
L₁, L₂, L ₃, L_Four・ ・ ・ L_TenAltitude is 1 μm
L having a step difference of more than 50 nm₂Excluding the area
Remaining sum (L₁+ L₃+ L_Four＋ ‥ ＋ L_Ten) Sum
(L₁+ L₂+ L₃+ L_Four... + L_Ten)) Ratio [(L₁
+ L₃+ L_Four＋ ‥ ＋ L_Ten) / (L₁+ L₂+ L₃+ L_Four... + L
_Ten) × 100 (%)].

The composition of brass plating formed in the brass plating material and composite of the present invention is copper: 50-9.
Generally, 0 mass% and zinc: 50 to 10 mass% may be used, but from the viewpoint of balancing the adhesiveness and the wire drawability after plating, copper: 60 to 70 mass%, Zinc: about 40 to 30% is preferable.

Further, as typical examples of the material to be joined (base material) applicable in the present invention, linear ones such as steel cords and bead wires for rubber reinforcement can be mentioned, but in addition, rubber lining Material (for example, steel plate) or material for rubber roll (for example, steel for machine structure)
The present invention can be applied to any of the above, and the above effects can be effectively exhibited regardless of the application of the present invention.

The present invention will be described in more detail with reference to the following examples, but the following examples are not intended to limit the present invention, and any change in the design of the present invention can be made without departing from the spirit of the preceding and the following. It is included in the technical scope.

[0039]

Example: Brass wire plating (Cu: 63% by mass, Zn: 37%) is applied to the surface of a wire having a wire diameter of 0.5 to 1.7 mm, and before or after wire drawing to an intermediate wire diameter. Substantially Cu and Z on the brass plating surface by the sputtering method
An oxide film composed of n and Zn / Cu ≧ 1 was formed, and finally drawn to a wire diameter of 0.3 mm to obtain a test material. At this time, the thickness of the oxide film formed by sputtering is changed to 15 to 50 nm, the wire diameter for applying the oxide film is changed as described above, the wire diameter for brass plating is changed as described above, and the wire drawing is performed. Area reduction rate of each stage in 5-22%
(1) the maximum oxide film thickness on the brass plating surface, (2) the continuous length A of the oxide film having a thickness of 10 to 50 nm on the brass plating surface, (3) the ratio of the oxide film, (4) The difference between the highest point and the lowest point of the brass plating surface curve was controlled. The sputtering was performed at a partial pressure of argon of 10 ⁻¹ Pa and a film forming power of 5 W per 1 m of the steel wire, and the oxide film thickness was controlled by changing the sputtering time. As a conventional example, a steel wire having a wire diameter of 0.5 to 1.7 mm, Cu: 63% by mass,
Zn: 37 mass% brass plated, wire diameter 0.3
A test material that was finally drawn to a thickness of mm was also produced (Nos. 16 and 17 of Tables 1 and 2 below).

Next, three brass-plated steel wires having the above-mentioned wire diameter of 0.3 mm are twisted together, and based on ASTM D2229, as shown in FIG. 3 (5 in the drawing is a rubber material, 6 is 3
Mainly twisted steel wire) embedded in a rubber material and vulcanized and bonded. The vulcanization at this time was performed at 160 ° C. for 20 minutes. Subsequently, the three-strand steel wire was pulled out from the rubber, and the initial adhesiveness was evaluated by the adhesion state of the rubber on the steel wire after being pulled out. At this time, 100% of the rubber remained on the surface of the steel wire was rated as 10 points (good), and no sticking at all was rated as 0 point (bad), and was evaluated in 10 levels. The adhesion state of the rubber at this time is schematically shown in FIG. That is, FIG.
(A) is 10 points according to the above evaluation criteria, and FIG.
FIG. 4 (c) shows the points 0, and FIG. 4 (c) shows the points 0 respectively.

Regarding the brass-plated steel wire after the final wire drawing,
By the focused ion beam (FIB) processing method, a cross-section thin film sample perpendicular to the length direction of the steel wire is prepared, and the plated surface in the cross section is included at a magnification of 90,000 times with a transmission electron microscope (TEM). The outermost layer was arbitrarily observed in 10 visual fields in the range of 1 × 1 (μm). Then, on the outermost surface of the brass plating, a layer (oxide film layer) which is substantially composed of copper and zinc and has a zinc / copper composition ratio of 1.0 or more and contains oxygen (oxide film layer) is identified by EDX. The thickness and length were measured and the ratio R ₁ (%) was calculated. Further, the highest elevation point and the lowest elevation point were observed from the plating surface curve, and the occupancy rate was calculated. The results of these measurements are collectively shown in Table 1 below.

[0042]

[Table 1]

On the other hand, the rubber / steel wire composite after vulcanization joining
The FIB processing method, the steel wire traverses perpendicular to the length direction.
Surface thin film sample is prepared and is examined with a transmission electron microscope (TEM).
At a magnification of 90,000 times, the composite of
The area near the interface including the reaction layer and the oxide film should be within 1 × 1 (μm)
Arbitrarily 10 fields of view were observed. And at the complex interface
It consists of copper and zinc, and the ratio of zinc / copper exceeds 1.0,
The layer containing oxygen (oxide layer) was identified by EDX, and
By measuring the thickness and length of the oxide film, the ratio R ₂(%)
Was calculated. From the reaction layer / oxide film interface curve,
Observe the highest and lowest elevation points,
I calculated. In addition, use rubber / steel wire composite after vulcanization adhesion
Storage for 72 hours in a humid atmosphere of 75 ° C x RH 95%
After that, a pull-out test is performed in the same manner as above,
The adhered state was evaluated by the method described above. Cross the result
The results of the surface observation are shown in Table 2 below.

[0044]

[Table 2]

From these results, the following can be considered.
If the requirements specified in the present invention are satisfied (No. 1 to
10), it can be seen that good results are obtained for both the initial adhesiveness and the temporal adhesiveness. Incidentally, No. In No. 11, since the occupancy rate, which is a preferable requirement of the present invention, is small, the adhesiveness with time is slightly decreased, but it is still better than the conventional one.

On the other hand, in the case where the requirements defined by the present invention are not satisfied (Nos. 12 to 18), it is understood that any of the characteristics is deteriorated. That is, No. 12
In No. 1, the oxide film is thicker, 1
In No. 3, the oxide film having a thickness of 10 to 50 nm has a long continuous length. In No. 15, the oxide film ratios R ₁ and R ₂ were too large. In _No. 17, the maximum continuous length A and the ratio R ₁ are too large, and both the initial adhesiveness and the temporal adhesiveness are deteriorated. In addition, No. In the case of Nos. 14 and 16, the ratio R _{1 of the} oxide film was low, and although the initial adhesiveness was good, it was found that the temporal adhesiveness was deteriorated. Furthermore, No. For 18 samples, A (nm) ≦ 10 × R
_Since the relationship of ₁ (%) was not satisfied, the maximum continuous length B and the ratio R ₂ after vulcanization adhesion were out of the ranges specified by the present invention, and the adhesiveness with time deteriorated.

[0047]

EFFECTS OF THE INVENTION The present invention is configured as described above, and effectively prevents brittleness of an adhesive surface with the passage of time while maintaining good rubber adhesiveness during vulcanization adhesion and product finishing. As a result, a brass-plated material capable of exhibiting good adhesive properties over time, and a composite in which rubber is bonded to the brass-plated material to form a composite have been realized.

[Brief description of drawings]

FIG. 1 is an explanatory view schematically showing a surface layer cross section of a brass plating material of the present invention.

FIG. 2 is an explanatory view schematically showing an interface cross section of the composite of the present invention.

FIG. 3 is a diagram for explaining a state of an adhesiveness test.

FIG. 4 is a diagram schematically showing evaluation criteria for an adhesiveness test.

[Explanation of symbols]

1 base material 2 Brass plating 3a-3f oxide film 4 rubber 5 rubber material 6 3 strand steel wire

Continued front page    (72) Inventor Takenori Nakayama             1-5-5 Takatsukadai, Nishi-ku, Kobe City Stock Association             Company Kobe Steel Works, Kobe Research Institute (72) Inventor Tatsuya Yasunaga             1-5-5 Takatsukadai, Nishi-ku, Kobe City Stock Association             Company Kobe Steel Works, Kobe Research Institute (72) Inventor Toshiyuki Yamauchi             1081 Minamiyama, Sumiyoshi-cho, Ono City, Hyogo Prefecture             N Industry Co., Ltd. (72) Inventor Toshiaki Shimizu             1081 Minamiyama, Sumiyoshi-cho, Ono City, Hyogo Prefecture             N Industry Co., Ltd. (72) Inventor Michiru Doi             1081 Minamiyama, Sumiyoshi-cho, Ono City, Hyogo Prefecture             N Industry Co., Ltd. F term (reference) 3B153 BB15 CC52 FF12 FF16 GG13                 4F100 AA17C AA25C AB03A AB17B                       AB18B AB31B AN00D AR00C                       AT00A BA04 BA06 BA10A                       BA10D EH71B EJ06D EJ12C                       GB32 GB90 JK06 YY00C                 4K044 AA02 AB02 AB04 BA06 BA10                       BA12 BB03 BB08 BC05 CA02                       CA07 CA13 CA18 CA62

Claims (4)

[Claims] 1. A brass plating material in which a surface of a base material is brass-plated, and an oxide film containing copper and zinc and having a thickness of 50 nm or less is formed on the surface of the brass plating. The oxide film with a thickness of 10 nm or more,
The continuous length A (nm) on the plating surface in the cross-section observation field perpendicular to the brass plating surface is 500 nm or less, and the total of the continuous length A (nm) is the ratio R ₁ ( %) Occupying 5 to 60%, and further satisfying the relationship of A (nm) ≦ 10 × R ₁ (%), a brass-plated material having excellent adhesion to rubber. 2. The length observed in the right-angled cross section is 1 μm.
The brass plating according to claim 1, wherein in the surface curve of m, a region where the difference between the highest elevation point and the lowest elevation point is within 50 nm occupies 70% or more of the entire observation field of view of the plating surface. material. 3. A composite body in which rubber is vulcanized and bonded to the surface of a brass plating material, and a reaction layer containing copper, zinc and sulfur near the interface between the brass plating surface and the rubber in the composite body. Is formed in the rubber, and an oxide film containing copper and zinc and having a thickness of 50 nm or less is formed on the brass plating side. Among them, the oxide film having a thickness of 10 nm or more is an observation field at a right angle to the brass plating surface. The continuous length B on the interface adjacent to the reaction layer in
(Nm) is 1000 nm or less, and the total of the continuous lengths B (nm) occupies 50 to 90% of the ratio R ₂ (%) to the total length of the observation visual field of the plating surface. body. 4. The difference between the highest elevation point and the lowest elevation point is 5 in the interface curve having a length of 1 μm on the interface where the oxide film observed in the right-angled cross-sectional view is adjacent to the reaction layer.
The composite according to claim 3, wherein the region within 0 nm occupies 70% or more of the entire length of the observation visual field of the plating surface.