JPS62285926A - Reinforcement for rubber - Google Patents

Abstract

PURPOSE:To obtain the title reinforcement excellent in adhesion to rubber and useful as a reinforcement for tires, etc., by forming a cobalt plating layer of a specified thickness on the surface of a continuous filament of an amorphous alloy. CONSTITUTION:A cobalt plating layer of an average thickness of 0.01-0.15mum is formed on the surface of an iron or iron-cobalt amorphous alloy filament, which is preferably a drawn wire of an area reduction ratio >=10% (e.g., filament of Fe70Cr8Si10B12) or of a strand wire formed by using said filament as an elementary wire by electroplating in an acidic plating bath or by a dry processing such as ion plating.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention (Industrial Application Field) Regarding the application of amorphous alloy as a reinforcing material for rubber, the amorphous alloy filament can be By increasing the adhesion of the plating and the adhesion between the plating and the rubber, we are improving the properties of amorphous alloys that could not be fully demonstrated due to poor adhesion to rubber, such as high strength, The aim is to realize a reinforcing effect on rubber by fully utilizing its high fatigue properties and high corrosion resistance, thereby making it possible to apply amorphous alloys as reinforcing materials to various rubber products.

Currently, amorphous alloys are being developed and researched to be put into practical use as magnetic materials due to their unique electrical and magnetic properties, but their mechanical and chemical properties are also not found in conventional materials. Not high strength, high corrosion resistance etc? It is also very noteworthy as a structural material. For example, it is expected to be applied as a composite material to rubber reinforcing materials, especially belts and carcass ply materials in tires.

(Prior art) In recent years, tires have been required to have a high level of performance in terms of running life, high-speed running performance, safety, etc., and in order to meet this demand, high carbon steel containing 0.7 to 1 lL9 heavy IchC is used to make more than 90% of the tires. A pneumatic tire using a steel cord made of thin filament wire drawn with a high cross-sectional reduction rate has been developed, and its usage is currently rapidly increasing.

However, with this steel cord, there is a decrease in strength due to rusting (rust), corrosion fatigue rupture due to water contained in the rubber, and a decrease in filament cross section due to so-called fretting, where filaments rub against each other and wear out. The disadvantage of reduced strength due to this is seen as a problem.

From this point of view, amorphous alloys have extremely high corrosion resistance,
If iron-based amorphous alloy filaments containing small amounts of Cr, Mo, and Ni, which can exhibit high wear resistance, can be used as reinforcing materials for tires, it will dramatically increase the durability life and have the characteristic of low specific gravity. As a result, the weight of the cord used can be reduced, and the weight of the tire can be expected to be reduced with the same case strength.

Toguni recently published Japanese Patent Publication No. 57-52550, 57-1! 1
As shown in Publications No. 42AB and No. 57-1/+1128, there is a manufacturing technology in which filaments with a circular cross section can be obtained relatively stably as a continuous wire by injection spinning of molten metal into a refrigerant. It is becoming established, and the possibility of application to tires is wide open.
No. 0702 and other Japanese Patent Application Laid-Open No. 61-47BS-9, A
As seen in various publications such as No. 1-47840, techniques for twisting cords into cords for use in tires and for improving the toughness of filament wires have been proposed.

Now, as mentioned above, amorphous alloys have the required properties such as high strength, high Young's modulus, and high fatigue resistance as reinforcing materials for rubber, and can be expected to significantly improve the reinforcing effect. In order to achieve this effect, it is necessary to provide excellent adhesion to the rubber.

In order to achieve excellent adhesion with rubber, steel cords are coated with so-called brass plating on wire rods with a diameter of 1.0 to 5 mφ, and then drawn into fine-diameter filaments to ensure excellent adhesion with rubber during subsequent vulcanization. increase the reactivity of
Good adhesion is obtained.

However, when considering the application of twisted or combined amorphous alloy filaments as a tire cord, for example, the filaments are produced by injecting molten metal and direct spinning to the extent that can be obtained by the above-mentioned wire drawing. In that case, sufficient adhesion with rubber cannot be expected by using the commonly used methods (plating and subsequent wire drawing).

Therefore, as a method for obtaining adhesion between the amorphous alloy filament and the rubber, the main methods are as follows: (1) Adding a metal element that can promote adhesion to the rubber into the alloy.

■ Apply adhesive to the surface of the amorphous alloy in the same way as for organic fiber cords.

■ Examine the plating material applied to the amorphous alloy surface.

There are many things that can be considered.

In the past, various concrete methods have been considered to deal with these problems. For example, regarding
No. 45401 each publication describes C! which has the possibility of adhesion to rubber. u, Zn.

It is stated that adhesion to rubber can be achieved by adding O of N5Ca and the like in an amount of 1 to 3 atoms. Also, in Japanese Patent Application Laid-Open No. 57-160702, N1 or 0o
This shows that excellent adhesion can be obtained by adding f5 to 2o atoms.

As for (1), as disclosed in Japanese Patent Application Laid-open No. 59-220546, bonding with rubber is possible after dipping and baking treatment with a resorcinol-formaldehyde-latex adhesive commonly used in organic fiber cords. It has been shown that

Regarding ■, in Japanese Patent Publication No. 57-1597, it is possible to directly apply brass plating to an amorphous alloy filament as a general method and obtain adhesion 2 with rubber without undergoing wire drawing. It has been stated.

However, after carefully examining the content of the methods proposed above and evaluating their feasibility and validity2, we found that most of the methods are essentially impossible to bond, or are weak or insufficient. Met.

For example, in the method (2), adding Cu to the alloy significantly reduces the ability to form an amorphous state, and in reality, an amorphous alloy to which Cu is added cannot be obtained.

Also, does the addition of Ni and Co certainly have adhesive properties? However, in order to obtain a stable level, a large amount of addition is required, which simultaneously reduces the tensile strength and makes it difficult to serve as a reinforcing material.

In method (2), the initial adhesion reaches the expected good level by dipping the adhesive, but the adhesion stability under heat aging conditions and high humidity atmosphere is considerably inferior to that of brass plating. , is not sufficient as a reinforcing material for rubber.

However, when plating an amorphous alloy using method (2), the adhesion between the two is generally poor, and brass plating also has insufficient adhesion to an amorphous base. In particular, this brass plating has poor reactivity with rubber when it is in the state of the case, and may require some processing such as wire drawing. If it is not applied, it will be difficult to cause an adhesive reaction with the rubber.

As described above, the conventionally disclosed technology has been designed to achieve perfect adhesion to rubber, fully exhibit the characteristics of amorphous alloys, and exhibit excellent effects as a reinforcing material for rubber. It was something that could not be reached.

(Problems to be Solved by the Invention) In order to exhibit excellent performance as a reinforcing material for rubber, it is essential to search for a method to obtain stable adhesion to rubber. As mentioned above, one method is to add elements effective for adhesion into the alloy, but in order to achieve stable adhesion, it is necessary to increase the amount, and at the same time, it is necessary to increase the amount of elements that are effective for adhesion. It is possible to reduce the physical properties of the dog.

Furthermore, the method of applying an adhesive inherently does not have a strong bonding force to all metals that do not have functional groups, and is particularly unstable in terms of stability against moist heat.

Therefore, the inventors searched for the optimal method to ensure adhesiveness through plating, which can effectively utilize strong chemical bonds as an adhesive system.

The points required for this type of plating are that good adhesion between the amorphous alloy base and the plating 1 should not easily cause peeling, and that the vulcanization reaction between the plating and the rubber should be achieved. The two points are that it induces an excellent adhesive bonding reaction.

In view of the above, the inventors believe that there is a good bonding reaction between the rubber and the rubber. We searched for various lubricating materials that would simultaneously satisfy adhesion to amorphous metal bases, and found that cobalt plating along with zinc had already been clarified by the inventor in Japanese Patent Application No. 59-214091. It has been found that the treatment also exhibits excellent effects under optimal treatment conditions.

Based on the results of the study, we used cobalt plating to improve the adhesion with the amorphous alloy and the adhesion between rubber.
Excellent performance as a reinforcing material for rubber; for example, when used in tire belts or carcass, it takes full advantage of the characteristics of amorphous alloys to improve durability, and reduces the weight of tires by reducing the weight of the hood used. It is an object of this invention to achieve.

(Problem? No solution) This invention is a continuous filament of an amorphous alloy,
This reinforcing material for rubber is characterized by having a cobalt plating layer formed on the surface of the filament, which provides adhesiveness to the rubber used.

That is, the present invention is a rubber reinforcing material made of a continuous filament of an amorphous alloy having a cobalt plating layer on its surface, and a rubber reinforcing material made of a twisted wire cord having the continuous filament as a wire. In the latter case, the twisted structure can be of any suitable type, and the cobalt plating can also be performed after forming a twisted wire cord whose strands are continuous filaments of an amorphous alloy.

The cobalt plating may be performed by electroplating using a commonly used acidic plating bath or by dry processing such as ion grating.

By the way, cobalt metal is reactive with rubber.

Although the bondability is very good, it tends to be difficult to obtain adhesion with an amorphous alloy substrate. uses a cobalt sulfate bath, and its pFl is reduced to 2
．． Cobalt plating treatment is carried out under relatively strong acidity bath conditions of 5 or less, and after surface etching using ion beam or plasma in the case of dry treatment, cobalt plating treatment is performed by sputter deposition. Adhesion, close contact with amorphous alloy base? We have found that this is the best way to achieve both.

Even in the case of the sidewall described above, the thickness of the cobalt plating 1 is preferably 0.01 to 0.15μ on average.

If the average thickness of the plating is less than 0.01 μm, there will be areas where the plating is not applied uniformly, resulting in decreased adhesion; When +S'fe is exceeded, it still shows a decreasing tendency.The reason for this is not completely clear, but it may be because if the plating sound becomes too thick, cracks in the plating layer will easily occur due to fatigue etc. when applied to tires etc. Conceivable.

Here, iron-based and iron-cobalt-based filaments are particularly suitable as the amorphous alloy filament. In other words, there are several amorphous alloys that can be continuously spun into filaments, such as palladium-based and iron-based alloys, but from the perspective of tire application, the only one that can achieve strength and elongation equal to or higher than current piano wire material is However, considering fatigue resistance, corrosion resistance, and economic efficiency, iron-based materials and mixed iron-cobalt systems are promising.

For example, as an iron-based alloy, Feg SS 116 B+
. , F. cr8BitoB, etc., and iron-cobalt alloys include Fe4oCo3. l5iI(I B
12 etc.

Still more preferably, after spinning, the wire is drawn at a reduction in area of 10 mm or more, which improves the strength and elongation and also improves the adhesion between the amorphous alloy and the cobalt plating. Shows stronger adhesion than the original one.

(Example) Example 1 An alloy base material melted to a composition consisting of Fs=g Cr8Sino B+2 was heated and melted to about 1200°C in a quartz tube with a nozzle hole at the tip, and then cooled to about 5°C. An amorphous alloy filament of 10 tons and about 500 units was produced by a spinning method in which argon gas was injected into water through a nozzle hole.

The spinning diameter was approximately 0.14111!1φ, and then wire drawing was performed using several dies to 012=φ (cross-section reduction rate 14
H) The obtained filament is twisted into a tire cord as a bare wire, and in this case, the twisted structure is
The twisting conditions were a tubular one-way type and a twisting speed of 10 m/min.

Various thicknesses for this stranded cord? A different cobalt plating process was applied to tires.

The adhesion properties of the tires when new and after running on drums were compared with those plated with other metals, those coated with adhesive, and the current high carbon steel cord plated with brass.

The method of application to tires and test conditions on drums are as follows.

Tire size: 165SR15 Application: The above stranded cord was applied as the outer layer belt 3 to a tire having two belts 1 shown in FIG. Perto Dorito's driving was 25 per 25 width. Note that 2 in the figure is a carcass.

Drum conditions: Speed...1100k/H Load...71
5100% load internal pressure - zoKg/J, mileage + 6
0. For the adhesion of C100k+n when new and after running on the drum, the outer belt was cut out from the tire and used as an adhesion test sample. The results are shown in Table 1.

The plating thickness in Table 1 was determined by eluating the cobalt plating layer from the code after plating with 6NHC/diluted 2 to 3 times and quantifying it with an atomic absorption spectrophotometer.

Moreover, the adhesive strength was expressed as the peel resistance force per adhesive.

Furthermore, the state of rubber adhesion was expressed as the σ fraction of the rubber covered area on the cord to the cord surface area.

Note that the cobalt plating treatment was investigated using electroplating treatment under the following conditions.

Plating bath composition: Co504200? /l pH1
, 8 current density: toA/a-'' The plating thickness was changed depending on the processing time.

Cobalt-plated amorphous alloy cords, especially those with a plating thickness in the range of CLO 1 to 0.15μ, are equivalent to or better than current brass-plated high carbon steel cords, both when new and after running. It was confirmed that adhesive stability was exhibited.

Example 2 Next, the superiority of the amorphous alloy cord was confirmed from the viewpoint of corrosion fatigue resistance. 44 of Example 1 described above was used as the optimum plating treatment, and as a comparative example, it was used with the current high carbon cord plated with brass for evaluation. The applied tire size, application method, and test conditions are shown below.

0.12 for each of the amorphous alloy filament and the current carbon A filament as cusply materials. Code p@25 for a 1×12 structure twisted using φ wire. A treat containing 50 pieces was prepared and applied.

Test case: Speed...60 ka/Fl Load...7
The drum was run at 15100% load internal pressure. At this time, about 500 CH of water was sealed between the tube inside the tire and the inner lychee, and the lifespan until the cord broke due to corrosion was confirmed. compared. The results are shown in Table 2.

Table 2 (Confirmed with n-2).

(Effects of the Invention) According to the present invention, when an amorphous alloy filament is used as a reinforcing material for rubber, the adhesion of the filament to the rubber can be significantly enhanced, and the characteristics of the filament can be maximized. It can be realized.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a cord showing one specific example of the rubber reinforcing material according to the present invention, and FIG. 2 is a cross-sectional view of a tire to which the rubber reinforcing material of the present invention is applied. No. 10 Ka 2

Claims (6)

[Claims] (1) A reinforcing material for rubber consisting of continuous filaments of an amorphous alloy having a cobalt plating layer on the surface. (2) A reinforcing material for rubber consisting of a twisted wire cord whose strands are continuous filaments of an amorphous alloy having a cobalt-plated layer on the surface. (3) A reinforcing material for rubber formed by forming a cobalt plating layer on the surface of a stranded cord whose wires are continuous filaments of an amorphous alloy. (4) Cobalt plating layer has an average thickness of 0.01 to 0.15
Claim 1, 2 or 3 having μm
Reinforcing material for rubber as described in Section. (5) Claims 1, 2, 3, or 4, wherein the continuous filament is a filament of an iron-based amorphous alloy manufactured by a spinning method in which a melt having an amorphous alloy composition is injected into a refrigerant. Reinforcement material for rubber as described. (6) The reinforcing material for rubber according to claim 5, wherein the continuous filament is a drawn wire having a reduction in area of 10% or more.