JP2005314808A - Wire element superior in corrosion resistance for reinforcing rubber, and composite of rubber and the wire element for reinforcing rubber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wire element superior in corrosion resistance for reinforcing rubber; the wire element for reinforcing the rubber, which has adequate adhesive properties to the rubber in addition to the corrosion resistance; and a rubber composite consisting of the rubber and the wire element for reinforcing the rubber. <P>SOLUTION: The wire element for reinforcing the rubber superior in the corrosion resistance has a coating layer containing Cu and Zn on the surface of a steel strand, wherein the coating layer has such thickness that the total circumferential length of the steel strand in a circumferential region having the thickness of 0.1 μm or more is 50% or more with respect to the total circumferential length of the steel strand, when a cross section perpendicular to the longitudinal direction of the wire element is observed; and in the above circumferential region, contains (1) 50 to 95 mass% Cu by average in a region from the outermost surface of the coating layer to a 0.01 μm deep position, in a depth direction, and contains (2) 60 mass% or more Zn by average in a region from a 0.1 μm deep position from the outermost surface of the coating layer to the surface of the steel strand, in a depth direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a rubber reinforcing linear body and a composite of the rubber reinforcing linear body and rubber, for example, as a material for reinforcing rubber products such as tires, hoses, and industrial belts. The present invention relates to a rubber reinforcing linear body that can be suitably used, and a composite in which the rubber reinforcing linear body and rubber are combined.

  Conventionally, steel cords for rubber reinforcement have been used as materials for reinforcing rubber products such as tires, hoses, and industrial belts. The steel cord for reinforcing rubber is used to increase the strength of the rubber product by being in close contact with the rubber by being combined with the rubber. Therefore, good adhesiveness is required between the steel cord and rubber. Such a steel cord for reinforcing rubber is used for reinforcing a tire, for example.

  As a technique for improving the adhesion between a steel cord for rubber and rubber, for example, Patent Document 1 proposes a method of manufacturing a rubber reinforcing wire that has good wire drawing workability and good initial rubber adhesion. Has been. In this technique, a brass plating layer is formed on the surface of a high carbon steel wire, then a copper plating layer is formed on the brass plating layer, and then the resulting wire is drawn into a brass plate. And copper plating are mechanically alloyed. When brass plating and copper plating are alloyed, a coating layer with a higher Cu content is formed on the surface along the depth direction, but Cu existing on the outermost surface of the coating layer generates an appropriate sulfide between the rubber and the rubber. In addition, the adhesion between the two is enhanced.

However, when a crack or the like enters a rubber product reinforced with a steel cord for reinforcing rubber, the steel cord inside the rubber product may be corroded due to water intrusion from the crack. In particular, it causes corrosion fatigue in the carcass portion where repeated stress is applied. However, in the above-mentioned Patent Document 1, no consideration is given to the corrosion of the steel cord.
JP-A-11-179419 (see [Claims] and [0009])

  This invention is made | formed in view of such a condition, The objective is to provide the linear body for rubber reinforcement excellent in corrosion resistance. Another object of the present invention is to provide a rubber reinforcing wire having good adhesion to rubber in addition to corrosion resistance. Still another object is to provide a rubber composite in which the rubber reinforcing linear body and rubber are combined.

  The rubber reinforcing linear body excellent in corrosion resistance according to the present invention that has solved the above problems is a rubber reinforcing linear body having a coating layer containing Cu and Zn on the surface of a steel element wire. When the cross section perpendicular to the longitudinal direction of the filament is observed, the sum of the circumferential lengths of the steel strands in the circumferential region where the coating layer thickness is 0.1 μm or more is the circumferential direction of the steel strands. 50% or more with respect to the total length, and (1) the average Cu content in the depth direction region from the outermost surface of the coating layer to the depth of 0.01 μm is 50 to 95% by mass with respect to the circumferential direction region. In addition, (2) it has a gist in that the average Zn content in the depth direction region from the position where the depth from the outermost surface of the coating layer is 0.1 μm to the surface of the steel strand is 60% by mass or more. . When the average Cu content is 60 to 85% by mass, in addition to the above corrosion resistance, the adhesion to rubber is also good. A rubber composite in which the rubber reinforcing linear body and rubber are combined is also included in the scope of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, the linear body for rubber reinforcement excellent in corrosion resistance can be provided. Moreover, according to this invention, in addition to corrosion resistance, the rubber | gum reinforcement linear object body with favorable adhesiveness with rubber | gum can be provided. Furthermore, according to this invention, the rubber composite_body | complex in which the said linear body for rubber reinforcement and rubber | gum are compounded can be provided.

  In the above-mentioned Patent Document 1, by forming an alloy of brass plating and copper plating formed on a steel wire, a rubber reinforcing linear body having a coating layer with a higher Cu content is formed on the surface. Cu existing on the outermost surface forms an appropriate sulfide with the rubber, so that the adhesion between the rubber and the rubber reinforcing filament is improved.

  However, since Cu is a noble metal rather than a steel wire, for example, when a crack or the like enters a rubber product reinforced with a rubber reinforcing linear body and water enters the inside, it is lower than Cu. It was found that steel wires made of metal are preferentially corroded. In particular, in Patent Document 1, the reason will be described later, but the component composition of the plating layer in the vicinity of the surface of the steel element wire is not strictly defined, so that the obtained rubber reinforcing filament is inferior in corrosion resistance.

  Therefore, the present inventors have made extensive studies to increase the corrosion resistance of the rubber reinforcing linear body. As a result, when a cross section perpendicular to the longitudinal direction of the rubber reinforcing linear body having a coating layer containing Cu and Zn is observed on the surface of the steel wire, the coating layer thickness is 0.1 μm or more. If the sum of the circumferential lengths of the steel strands in the region is not less than a predetermined length relative to the entire circumferential length of the steel strands, and the component composition of the coating layer in the circumferential region is appropriately adjusted, the above problem As a result, the present invention has been completed. Hereinafter, the function and effect of the present invention will be described.

  The rubber reinforcing linear body according to the present invention has a coating layer containing Cu and Zn on the surface of a steel element wire. The component composition of the steel strand is not particularly limited, and a steel strand generally used as a material constituting the rubber reinforcing linear body can be used.

  The rubber reinforcing linear body according to the present invention has a coating layer thickness including Cu and Zn of 0.1 μm or more when a cross section perpendicular to the longitudinal direction of the linear body (that is, a cross section) is observed. The sum total of the circumferential length of the steel strand in a certain circumferential region is 50% or more with respect to the circumferential total length of the steel strand. This will be described with reference to the drawings.

  FIG. 1 is a schematic view of a cross section perpendicular to the longitudinal direction of a rubber reinforcing linear body. In the figure, 1 is a steel wire, 2 is a coating layer, 3 is a line indicating a position where the depth from the outermost surface of the coating layer is 0.1 μm, and A is a circumferential region where the coating layer thickness is 0.1 μm or more. , A is the circumferential length of the steel wire 1 in the circumferential region A where the coating layer thickness is 0.1 μm or more, B is the circumferential region where the coating layer thickness is less than 0.1 μm, and b is the coating layer thickness. The circumferential length of the steel strand 1 in the circumferential region B that is less than 0.1 μm, and L indicates the overall circumferential length of the steel strand 1, respectively.

  The surface of the steel wire 1 is smooth at first glance and no large irregularities are seen. However, since the surface of the steel wire 1 has minute irregularities in micro units, when the coating layer 2 is provided on the surface of the steel wire 1, the coating layer thickness becomes 0.1 μm or more as shown in FIG. The circumferential region A and the circumferential region B having a coating layer thickness of less than 0.1 μm coexist. At this time, if the circumferential region B having a coating layer thickness of less than 0.1 μm is larger than the circumferential region A, the adhesiveness between the rubber reinforcing linear body and the rubber decreases because the coating layer thickness is small, The quality of rubber products as a reinforcing material deteriorates.

  Therefore, in the rubber reinforcing linear body according to the present invention, when the cross section perpendicular to the longitudinal direction of the linear body is observed, the thickness of the steel element wire 1 in the circumferential region A in which the coating layer thickness is 0.1 μm or more. The sum total of the circumferential length a is 50% or more with respect to the circumferential total length L of the steel strand 1.

  Here, the circumferential length a of the steel wire 1 in the circumferential region A having a coating layer thickness of 0.1 μm or more is the steel wire 1 when a cross section perpendicular to the longitudinal direction of the filament is observed. Is the length in the circumferential direction of the steel strand 1 obtained by connecting the intersection of the circumferential length L in the above and the line 3 indicating the position where the depth from the outermost surface of the coating layer 2 is 0.1 μm. The circumferential length a of the steel wire 1 in the circumferential region A where the coating layer thickness obtained in this way is 0.1 μm or more is calculated, and the sum is obtained.

And from the value of the obtained sum total and the circumferential direction full length L of the steel strand 1, the ratio of the sum total with respect to the circumferential direction full length L of the steel strand 1 is computable by the following (1) formula.
Ratio (%) = [sum of circumferential lengths of steel strands in the circumferential region where the coating layer thickness is 0.1 μm or more] / [total circumferential length of steel strands] × 100 (1)

  In the rubber reinforcing linear body of the present invention, the above ratio is set to 50% or more. When the ratio is less than 50%, the portion with a small coating layer thickness increases, and thus the adhesion to rubber becomes insufficient. Preferably it is 55% or more, More preferably, it is 60% or more, and the one where this ratio is high is desirable. Most preferably, it is 100%. 100% means that the thickness of the coating layer 2 formed on the surface of the steel wire 1 is all 0.1 μm or more.

  In FIG. 1, the surface of the steel wire 1 has irregularities, but the surface of the rubber reinforcing linear body obtained by coating the steel strand 1 has no irregularities and is perpendicular to the longitudinal direction. The cross-sectional shape was almost a circle. However, this invention is not limited to this, About the steel strand 1 with the unevenness | corrugation on the surface, the coating layer 2 may be provided along this unevenness | corrugation (not shown). That is, a rubber reinforcing filament having a cross section perpendicular to the longitudinal direction is also included in the scope of the present invention.

  What is necessary is just to observe the cross section perpendicular | vertical to the longitudinal direction of the linear body for rubber reinforcement, for example using a scanning electron microscope (SEM). The observation magnification at this time may be about 10,000 to 50,000 times.

  The rubber reinforcing linear body according to the present invention has an average Cu content in a depth direction region from the outermost surface of the coating layer to a depth of 0.01 μm in the circumferential region where the coating layer thickness is 0.1 μm or more. The average Zn content in the region in the depth direction from the position where the depth from the outermost surface of the coating layer is 0.1 μm to the surface of the steel element wire is 60% by mass or more. is important.

  If the average Cu content in the depth direction region from the outermost surface of the coating layer to a depth of 0.01 μm is 50% by mass or more, when the rubber reinforcing linear body and the rubber are combined, the depth Cu existing in the directional region reacts with S contained in the rubber to form a sulfide, and adhesion with the rubber is increased. Preferably it is 55 mass% or more, More preferably, it is 60 mass% or more. However, when the average Cu content is 60% by mass or more, the amount of Cu sulfide increases, and the adhesive strength at the interface between the rubber and the rubber reinforcing linear body exceeds the strength of the rubber itself. Therefore, for example, when pulling out the rubber reinforcing filament from the composite of rubber reinforcing filament and rubber, the breakage at the time of pulling out does not occur at the interface but occurs in the rubber, so the average Cu content is If it is 60 mass% or more, the pulling strength is almost constant, which is desirable. However, when the average Cu content is 100% by mass, the reaction between Cu and rubber becomes excessive when the rubber reinforcing linear body and rubber are compounded, and the interfacial strength decreases instead, so the average Cu content. Is 95% by mass or less. Preferably it is 90 mass% or less, More preferably, it is 85 mass% or less.

  In particular, when the average Cu content is in the range of 60 to 85% by mass, in addition to the improvement of the corrosion resistance, the adhesion between the rubber and the reinforcing rod is also improved.

  On the other hand, the average Zn content in the region in the depth direction from the position where the depth from the outermost surface of the coating layer reaches the surface of the steel element wire is 60% by mass or more. Of the coating layers formed on the surface of the steel strand, if Zn is present in the vicinity of the surface of the steel strand, Zn is a base metal rather than the steel strand, so Zn is preferred over the steel strand. Corrosion of steel wire can be suppressed. The average Zn content is preferably 65% by mass or more, more preferably 70% by mass or more, still more preferably 75% by mass or more, and particularly preferably 80% by mass or more. Most preferably, it is 100% by mass, and the steel wire is desirably entirely covered with a coating layer made of Zn.

  Depth direction until the average Cu content in the depth direction region from the outermost surface of the coating layer to the depth of 0.01 μm and the depth from the outermost surface of the coating layer reaches the surface of the steel wire from the position of 0.1 μm The average Zn content in the region can be measured by the following procedure. After selecting any five points from the circumferential region where the coating layer thickness is 0.1 μm or more and processing the sample into a cross-sectional observation sample with a focused ion beam processing observation apparatus (FIB) with microsampling, the energy dispersive fluorescent X Using a transmission electron microscope (TEM) with a line analyzer (EDX), a bright field image of about 100,000 to 500,000 times is obtained using an electron beam with an acceleration voltage of 200 kV. Next, electrons are placed in the depth direction region from the outermost surface of the coating layer to a depth of 0.01 μm, or in the depth direction region from the position where the depth from the outermost surface of the coating layer reaches 0.1 μm to the steel wire surface. By irradiating a line, the component composition of the coating layer in these depth regions is quantitatively analyzed. In addition, the number of electron beam irradiation locations is about 3 to 5, and the average of the measured values is the content.

  As the FIB, for example, “FB-2000A” manufactured by Hitachi, Ltd., and for the transmission electron microscope with EDX, for example, “HF-2000” manufactured by Hitachi, Ltd. can be used.

  The rubber reinforcing linear body according to the present invention satisfies the above-mentioned requirements, and its manufacturing method is not particularly limited, but the following manufacturing method can be suitably employed.

  As a method for forming a coating layer containing Cu and Zn on the surface of the steel wire, a sputtering method can be suitably applied. This is because the component composition of the coating layer can be easily controlled by changing the composition of the target if the sputtering method is used. That is, since the composition of the target becomes equal to the component composition of the coating layer, the composition of the target may be controlled in order to adjust the component composition of the coating layer. In the sputtering method, the thickness of the coating layer can be easily controlled by changing the film formation time. Further, when the sputtering method is employed, the component composition in the depth direction can be strictly controlled at the 0.01 to 0.1 μm level as described above. Specifically, when the surface of the steel wire is sputtered using a target having a relatively high Zn content and then sputtered using a target having a relatively high Cu content, the steel wire of the coating layer is obtained. Nearby components become Zn-rich, and the vicinity of the outermost surface of the coating layer becomes Cu-rich.

  As the target having a relatively large Zn content, the average Zn content in the depth direction region from the position where the depth from the outermost surface of the coating layer reaches 0.1 μm to the steel element wire surface is an appropriate range. Therefore, it is preferable to use a target containing 50 to 100% by mass of Zn. The remaining component of the target is not particularly limited, and examples thereof include Cu, Al, Mg, Co, and Ni. In addition, in order to improve the corrosion resistance of a steel strand, since it is preferable that the remainder component of a target is also comprised with a base metal rather than a steel strand, what is especially Al and Mg is recommended.

  As the target having a relatively high Cu content, in order to control the average Cu content in the depth direction region from the outermost surface of the coating layer to a depth of 0.01 μm within an appropriate range, Cu is 45 to 100. It is preferable to use a target containing mass%. The remaining component of the target is not particularly limited, and examples thereof include Zn, Co, Ni, Al, and Mg.

  As described above, after sputtering using a Zn-containing target and sputtering using a Cu-containing target, the coating layer formed on the surface of the steel wire has a two-layer structure, but in the present invention, When the entire coating layer formed on the surface of the steel wire is viewed, it is sufficient that Zn and Cu are included. Therefore, for example, even when Cu is not contained in a layer obtained by sputtering using a Zn-containing target or when Zn is not contained in a layer obtained by sputtering using a Cu-containing target, If Zn and Cu are contained when the entire coating layer formed on the surface of the steel wire is viewed, it is included in the scope of the present invention.

  Next, when the steel element wire having the coating layer is drawn, a rubber reinforcing linear body is obtained. The drawing condition is not particularly limited, but it is preferable to carry out the drawing so that the diameter of the rubber reinforcing linear body obtained after the drawing is about 0.05 to 0.5 mm. Further, a plurality of rubber reinforcing linear bodies obtained by wire drawing may be twisted.

  In the above description, the case where the sputtering method is employed has been described mainly. However, the present invention is not limited to this, and the average Zn content in the vicinity of the surface of the steel strand and the average Cu content in the vicinity of the surface of the striatum It is sufficient if the amount satisfies the above range. That is, for example, the surface of the steel element wire may be subjected to Zn plating by a wet method such as electroplating, then Cu plating, and then a Cu-Zn alloy plating layer may be formed by heat diffusion treatment, followed by wire drawing. In consideration of the fact that Zn diffuses and reacts with the steel wire during thermal diffusion to reduce the adhesion of the plating layer, brass plating with a Zn content of 60% by mass or more on the surface of the steel wire by hot dipping etc. After coating, the surface may be coated with brass plating having a Cu content of 50 to 95% by mass, and then directly drawn without thermal diffusion treatment.

  The rubber reinforcing linear body according to the present invention can be suitably used as a material for reinforcing tires, hoses, industrial belts, and the like. That is, a rubber composite (for example, a tire, a hose, an industrial belt, etc.) in which the rubber reinforcing linear body and rubber according to the present invention are combined is also included in the present invention.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are not intended to limit the present invention, and may be implemented with appropriate modifications within a range that can meet the purpose described above and below. These are all possible and are within the scope of the present invention.

[Experimental Example 1]
A Zn-containing brass plating layer is formed on the surface of a steel strand having a diameter of 1 mm by sputtering using a target containing 50 to 100% by mass of Zn (the remaining component is Cu). A Cu-containing brass plating layer was formed by a sputtering method using a target containing -100% by mass (the remaining component is Zn). Hereinafter, the Zn-containing brass plating layer and the Cu-containing brass plating layer may be collectively referred to as a “coating layer”.

  Next, the steel strand having a coating layer was drawn under various conditions until the diameter became 0.2 mm to obtain a rubber reinforcing linear body.

  The cross section perpendicular to the longitudinal direction of the obtained rubber reinforcing linear body was observed at 30000 times using SEM, and the total circumferential length of the steel strand was measured. Next, the thickness distribution of the coating layer is examined, and the peripheral length of the steel wire is divided into a circumferential region where the coating layer thickness is 0.1 μm or more and a circumferential region where the coating layer thickness is less than 0.1 μm. The circumferential length of the steel strand in the circumferential region where the coating layer thickness is 0.1 μm or more was calculated. The sum total of the calculated circumferential direction length was calculated | required, and the ratio of the said sum total with respect to the circumferential direction full length of the steel strand was computed from said (1) Formula. As a result, for the rubber reinforcing filaments shown in Table 1 below, the total ratio was 70%.

  Next, after selecting any five points from the circumferential region where the coating layer thickness is 0.1 μm or more and processing into a sample for cross-sectional observation with a FIB with microsampling (“FB-2000A” manufactured by Hitachi, Ltd.), Using a TEM with EDX (“HF-2000” manufactured by Hitachi, Ltd.) and following the above procedure, the depth direction region from the outermost surface of the coating layer to the depth of 0.01 μm (hereinafter referred to as “outermost surface portion”) Or in the depth direction region from the position where the depth from the outermost surface of the coating layer is 0.1 μm to the surface of the steel wire (hereinafter may be referred to as [lowermost part]) The component composition of the coating layer was quantitatively analyzed. The component composition was measured at five locations on the outermost surface portion and the lowermost portion, and five points were measured in the depth direction at each measurement location. And about the depth direction area (outermost surface part) from the outermost surface of the coating layer to the depth of 0.01 μm, the average Cu content, and the steel wire surface from the position where the depth from the outermost surface of the coating layer is 0.1 μm The average Zn content was calculated for each of the regions in the depth direction (lowermost part) until reaching the above. That is, the average means an average value measured at 25 points in order to measure the component composition at 5 points each at 5 measurement positions.

  Three twisted strands of rubber reinforcement obtained were embedded in rubber, then vulcanized, and vulcanized according to ASTM (American Society For Testing and Materials) D2229. The pullout strength was measured.

  Next, a test piece having a length of 10 m was cut out from the obtained reinforcing rod for rubber reinforcement, and the test piece was immersed in a 3% by mass NaCl aqueous solution for 100 hours, and then the corrosion weight loss of the steel wire before and after immersion was measured. did.

  The measured pull-out strength and corrosion weight loss were relatively evaluated using a standard rubber reinforcing wire as a comparison object. That is, the pulling strength and the corrosion weight loss were measured for the standard rubber reinforcing wire, and the relative values of the pulling strength and the corrosion weight loss of the rubber reinforcing wire obtained above were determined with the measured value as 100. .

  In addition, as a standard wire body for rubber reinforcement, a steel element wire was used that was plated with a single layer so that the component composition in the outermost surface portion and the lowermost portion was Cu: 63 mass% and Zn: 37 mass%. . When the cross section perpendicular to the longitudinal direction of this standard reinforcing rod for reinforcing rubber is observed, the sum of the circumferential lengths of the steel strands in the circumferential region where the coating layer thickness is 0.1 μm or more is the steel strand. It was 70% with respect to the full length in the circumferential direction.

  About the rubber reinforcing filament obtained as described above, the component composition in the depth direction region from the outermost surface of the coating layer to the depth of 0.01 μm, and the steel from the position where the depth from the outermost surface of the coating layer is 0.1 μm. The component composition in the depth direction region until reaching the surface of the strand is shown in Table 1 below. In Experimental Example 1, since a target composed of Cu and Zn was used, the outermost component and the lowermost component were also composed of Cu and Zn.

  In addition, the relative values of the pullout strength and the corrosion weight loss are shown in Table 1 below for each rubber reinforcing linear body.

  As is clear from Table 1, if the Cu content in the outermost surface portion is 50 to 95 mass% and the Zn content in the lowermost portion is 60 mass% or more, the relative value of corrosion weight loss is less than 100, It becomes a linear body for rubber reinforcement with excellent corrosion resistance. In particular, when the Cu content in the outermost surface portion is 60 to 85% by mass, the relative value of the pulling strength exceeds 100, and the rubber reinforcing linear body has good adhesion to rubber.

[Experiment 2]
In the same procedure as in Experimental Example 1, the component composition in the depth direction region from the outermost surface of the coating layer to the depth of 0.01 μm is Cu: 70 mass%, Zn: 30 mass%, and the depth from the outermost surface of the coating layer The component composition in the depth direction area | region until it reaches the steel strand surface from the position of 0.1 micrometer obtained the linear body for rubber reinforcement whose Cu: 5 mass% and Zn: 95 mass%.

  At this time, by changing the film formation time by sputtering, the sum of the circumferential lengths of the steel strands in the circumferential region where the coating layer thickness is 0.1 μm or more is set to the circumferential total length of the steel strands. It adjusted to the range of 40-100%.

  The pulling strength and corrosion weight loss were measured in the same manner as in Experimental Example 1 using the obtained rubber reinforcing wire, and the relative values were obtained in the same manner as in Experimental Example 1.

  Table 2 below shows the ratio of the total sum, the pullout strength, and the corrosion weight loss in the obtained rubber reinforcing linear body.

  As is apparent from Table 2, when the ratio of the above sum is 50% or more, the relative value of the corrosion weight loss is less than 100, and the filament for reinforcing a rubber having excellent corrosion resistance is obtained. However, even if the ratio of the above sum is 40% or more and less than 50%, the relative value of the corrosion weight loss is less than 100, and the corrosion resistance is excellent. However, the relative value of the pulling strength is remarkably reduced, and the adhesion with the rubber is reduced. It is not suitable for practical use because its properties deteriorate.

FIG. 1 is a schematic view of a cross section perpendicular to the longitudinal direction of a rubber reinforcing linear body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steel strand 2 Coating layer 3 Line A which shows the position where the depth from the outermost surface of a coating layer is 0.1 micrometer A circumferential direction area | region a coating layer thickness is 0.1 micrometer or more When coating layer thickness is 0.1 micrometer or more Full length B in the circumferential direction of the steel wire in a certain circumferential region Circumferential region b in which the coating layer thickness is less than 0.1 μm Full length L in the circumferential direction of the steel wire in the circumferential region in which the coating layer thickness is less than 0.1 μm Wire circumference

Claims (3)

A rubber reinforcing filament having a coating layer containing Cu and Zn on the surface of a steel wire,
When the cross section perpendicular to the longitudinal direction of the filament is observed, the total circumferential length of the steel strands in the circumferential region where the coating layer thickness is 0.1 μm or more is the total circumferential length of the steel strands. And more than 50%, and
About the said circumferential direction area | region, (1) While the average Cu content of the depth direction area | region from the outermost surface of a coating layer to the depth of 0.01 micrometer is 50-95 mass%, (2) Depth from the outermost surface of a coating layer A rubber reinforcing linear body excellent in corrosion resistance, characterized in that an average Zn content in a depth direction region from a position of 0.1 μm to the surface of a steel element wire is 60% by mass or more.   The linear body for rubber reinforcement according to claim 1, wherein the average Cu content is 60 to 85 mass%.   A rubber composite comprising the rubber reinforcing linear body according to claim 1 and rubber combined.

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