JP4328046B2 - tire - Google Patents

Description

【００３８】
【表２】

【００３９】
（付記）
トランスポリブタジエン：（合成法）特開平１１−１５８２０７号公報［００５４］による。（つまり、オーブンで乾燥させておいた７５０ｍｌのガラス製ボトルをブチルライナーと王冠で密封した。このボトルを冷却した後、乾燥ブタジエン／ヘキサンブレンド物（２２．３重量％）を２２３グラム仕込んだ。このモノマー溶液にランタントリス［ビス（２−エチルヘキシル）ホスフェート］（０．２７ミリモル）を加えた。これに続いてｎ−ＢｕＬｉ（１．08ミリモル）を加えた。上記ボトルを６５℃の水浴に２時間入れた。次に、溶媒を蒸発させることで白色粉末を得た。単離収率は８７％であった。）
コバルト塩：ナフテン酸コバルト
加硫促進剤：Ｎ，Ｎ’−ジシクロヘキシル−２−ベンゾチアゾリルスルフェンアミド（大内新興化学工業株式会社製 ノクセラーＤＺ）
ビスマレイミド：Ｎ，Ｎ’−（４，４’−ジフェニルメタン）ビスマレイミドスチールコード［従来品］：従来のブラスめっき（Ｃｕ６３重量％、Ｚｎ３７重量％、めっきの厚み少なくとも１５ｎｍ）を施している。なお、表面のＣｕは１５〜４５アトミック％である。
スチールコード［発明品］：本発明の組成のブラスめっきを施している。（Ｃｕ６３重量％、表層領域のＣｏ０．５〜５．０アトミック％、最表層のＣｕ１５〜４５アトミック％、めっきの平均厚み０．１３〜０．３μｍ）
老化防止剤：Ｎ−（１，３−ジメチル−ブチル）−Ｎ’−フェニル−ｐ−フェニレンジアミン（大内新興化学工業株式会社製 ノクラック６Ｃ）
【００４０】
上表のように、ビスマレイミドを配合したコーティングゴムは、高硬度、低発熱性、耐劣化性、外観性、接着性が揃って比較的高く、トランスポリブタジエンと併用したコーティングゴムは、高硬度、低発熱性、耐劣化性がより良好で、さらに、めっきを改良したスチールコードとの複合体にあっては、接着性が一層向上した。
【００４１】
【発明の効果】
以上説明したように、本発明のゴム−スチールコード複合体を使用したタイヤは、ゴムの硬さを増加させ、かつ低発熱性、スチールコードとの接着性、耐劣化性を損なうことのないゴム組成物を提供し、およびさらに接着性を向上できるスチールコードを提供し、これにより、車両用等の空気入り等のタイヤの耐久性を向上させることができる。
【図面の簡単な説明】
【図１】 イオンプランテーションによってＣｏをブラスめっき表面に注入した時のめっき表面から内部への深さ方向Ｃｏ含有量の分布を示す図である。
【図２】 コバルト金属塩を含むコロイドに浸漬、乾燥して２００℃でＣｏをめっき内部に熱拡散させた時のめっき表面から内部への深さ方向Ｃｏ含有量の分布を示す図である。
【図３】 ブラスめっきにおける各成分の深さ方向の濃度分布を示す図である。
【図４】 ブラスめっき表面のＣｏの状態をＸ線光電子分光法で回折したときのスペクトル模式図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tire using a rubber-steel cord composite, and more particularly, to a technique for improving a coating rubber of a steel cord with plating and a plated portion of the steel cord.
[0002]
[Prior art]
For example, a rubber composition applied as a coating rubber to a belt layer reinforced with a steel cord is an important rubber involved in tire durability. The performance required for this rubber composition includes (1) hardness, (2) low heat build-up, (3) adhesion to a steel cord, and (4) deterioration resistance. Among these, increasing the hardness of (1) is an effective means for suppressing the shear strain between the belt layers and improving the durability of the tire.
[0003]
In order to increase this hardness, (a) increase the amount of filler such as carbon black, (b) add resin, etc. (c) increase the amount of crosslinking agent such as sulfur. And (d) increasing the blending amount of the vulcanization accelerator.
[0004]
[Problems to be solved by the invention]
However, the increase in the blending amount of the fillers (a) and (b) and the addition of resin certainly increase the hardness, but lower the low heat buildup and deteriorate the heat buildup durability.
In addition, the increase in the amount of sulfur in the above (c) is that when left in an unvulcanized rubber state, sulfur blooms, the workability is remarkably lowered, and even if the tire is made, the deterioration resistance of the rubber As a result, tire durability may be reduced.
[0005]
Furthermore, the increase in the blending amount of the vulcanization accelerator (d) has no problem with workability, low heat build-up, and deterioration resistance, but if it is too much, the adhesion to the steel cord is reduced. There is a problem of doing.
Therefore, an object of the present invention is to provide a tire excellent in durability by improving a rubber-steel cord composite.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present inventor has obtained the following knowledge as a result of intensive studies and has completed the present invention.
In other words, bismaleimide directly crosslinks between polymers such as natural rubber without sulfur, so that the hardness of the rubber can be increased without impairing the low heat buildup and deterioration resistance of the rubber. Conceivable. It was also found that bismaleimide alone is effective, but addition of transpolybutadiene can suppress vulcanization reversion that is increased by bismaleimide, further improving hardness and heat generation. Furthermore, it has been found that the adhesion between rubber and steel cord is improved by using bismaleimide alone or in combination with bismaleimide and transpolybutadiene.
[0007]
On the other hand, cobalt salt acts as an adhesion promoter in rubber-steel cord adhesion, and is therefore necessary for promoting adhesion. At the same time, cobalt salt also has the effect of deteriorating the deterioration resistance of rubber.
Therefore, the amount of cobalt salt can be reduced by using bismaleimide alone or in combination with bismaleimide and transpolybutadiene.
Furthermore, it has been found that the adhesiveness can be further improved by combining this rubber composition with the novel steel cord of the present invention.
[0008]
The configuration of the present invention is as follows.
(1) A tire using a rubber-steel cord composite comprising a rubber composition in which bismaleimide is blended with at least one rubber component of natural rubber and diene-based synthetic rubber, and a steel cord, wherein the rubber The composition comprises 0.1 to 5 parts by weight of the bismaleimide with respect to 100 parts by weight of the rubber component, and the bismaleimide is N, N ′-(4,4′-diphenylmethane) bismaleimide . The steel cord is a monofilament steel cord made of one of the steel filaments on which the outermost copper concentration is brass-plated with a copper concentration of 15 to 45 atomic%, or multifilament steel formed by twisting these steel filaments. It is a code .
(2) The rubber composition further comprises 0.1 to 15 parts by weight of transpolybutadiene with respect to 100 parts by weight of the rubber component.
(3) The rubber component contains 50% by weight or more of natural rubber.
[0010]
(4) The steel cord has cobalt on the surface region of the peripheral surface from the surface of the steel filament plated with brass having a copper concentration of 15 to 45 atomic% on the outer surface to a depth of 15 nm inward in the filament radial direction. It is characterized by being a monofilament steel cord comprising one brass-plated filament containing at least one of atoms and nickel atoms, or a multifilament steel cord formed by twisting these steel filaments. Here, the “outermost layer” is the minimum unit length that can be measured by the apparatus, and is about 1 nm to 2 nm by X-ray photoelectron spectroscopy.
[0011]
(5) The total amount of cobalt atoms and nickel atoms contained in the surface layer region is not less than 0.1 atomic% and not more than the copper atom content in the surface layer region.
(6) The total amount of cobalt atoms and nickel atoms contained in the surface layer region is 0.5 to 5.0 atomic%.
(7) In the surface layer region, cobalt atoms and nickel atoms not included in the oxide are 50 atomic% or more of the total amount of cobalt atoms and nickel atoms contained in the surface layer region.
(8) The filament has a diameter of 0.40 mm or less.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail.
The tire of the present invention is provided with a rubber-steel cord composite comprising a steel cord and a specific rubber composition (coating rubber).
The rubber component of the coating rubber is composed of at least one of natural rubber and diene synthetic rubber, but preferably contains 50% by weight or more of natural rubber. This is because if it is less than 50% by weight, the adhesive properties and rubber breaking properties may be deteriorated. The synthetic rubber constituting the remainder of the rubber component includes styrene-butadiene rubber (SBR), butadiene rubber (BR), butyl rubber (IIR), halogenated butyl rubber (X-IIR), preferably brominated butyl rubber (Br- IIR), butyl rubber having a paramethylstyrene group (specifically, a copolymer of isobutylene and p-halogenated methylstyrene, etc.), ethylene / propylene / diene rubber (EPDM), isoprene rubber (IR) and the like. .
[0013]
In the case of SBR, a solution-polymerized SBR in which the vinyl bond content of the butadiene portion is 35 to 85% and the amount of bonded styrene is 30% by weight or less is preferable. This is because the vinyl bond content is 35% or more. This is because the heat aging resistance of the rubber can be improved, and by setting it to 85% or less, the fracture characteristics of the rubber can be maintained. Moreover, the adhesive fall can be suppressed by making the amount of bond styrene into 30 weight% or less.
[0014]
In the present invention, the blending amount of bismaleimide is 0.1 to 5 parts by weight per 100 parts by weight of the rubber component in both cases of bismaleimide alone and the combined use of bismaleimide and transpolybutadiene. If the amount is less than 0.1 part by weight, the blending effect cannot be exhibited. The bismaleimide used in the present invention is N, N ′-(4,4′-diphenylmethane) bismaleimide.
[0015]
The rubber composition used in the tire of the present invention preferably contains trans polybutadiene in order to further improve the fracture resistance. The trans polybutadiene preferably has a trans bond content of 82% to 98%, and more preferably 86% to 98% from the viewpoint of effects. Moreover, when the weight average molecular weight is 30,000-200,000, the workability at the time of unvulcanization can be improved and the fracture resistance of the vulcanized rubber can be maintained. The blending amount of trans polybutadiene is preferably from 0.1 to 15 parts by weight per 100 parts by weight of the rubber component from the viewpoint of compatibility with the rubber component, fracture resistance of the vulcanized rubber, and the like. Further, when 3 to 15 parts by weight, particularly 4 to 12 parts by weight is blended, the effect is great.
[0016]
In addition to the above components, the rubber composition in the present invention includes, as necessary, reinforcing fillers, silane coupling agents, vulcanizing agents, vulcanization accelerators, and vulcanization accelerators that are usually used in the rubber industry. An agent, an antioxidant, an ozone degradation inhibitor, an anti-aging agent, a process oil, zinc white (ZnO), stearic acid, and the like can be appropriately blended.
[0017]
Hereinafter, the steel cord with brass plating of the present invention will be described.
Now, in order to clarify the relationship between the component composition in the depth direction from the plating surface and the initial adhesiveness of the brass plating applied to the peripheral surface of the filament, the present inventor applied the brass plating filament that is normally used. Co ion implantation was performed to examine the adhesion to the coated rubber with the adhesion promoter reduced or not added. That is, using the ion plantation technique, the relationship between the ion implantation time and the Co content of the brass plating surface, and the relationship between the ionization rate of Co to be implanted and the Co content in the depth direction shown in FIG. By grasping in advance, the Co content of the plating surface layer was variously controlled, and the relationship with the initial adhesiveness was investigated.
[0018]
As a result, the inventors have newly found that the inclusion of Co from the plating surface to a depth of 15 nm is the most effective in improving the initial adhesiveness, and thus the present invention has been completed. That is, when the Co-containing region is expanded in the depth direction from the plating surface and the initial adhesiveness is evaluated in various stages of the expansion process of the region, the initial adhesiveness increases as the Co-containing region is expanded in the depth direction. Although it is improved, it has been found that even if the Co-containing region is expanded to a depth exceeding 15 nm, the initial adhesiveness is not further improved, and the effect is saturated at the depth of 15 nm. did.
[0019]
On the other hand, when the initial adhesiveness was similarly evaluated by increasing the Co content only on the plating surface, the effect of improving the initial adhesiveness was small unless Co was diffused to a certain depth. It was also found that the initial adhesiveness with the coated rubber, which was reduced or not added, was not at a level that could ensure the initial adhesion.
Therefore, the surface layer region is set to 15 nm. As described above, this is the main area that affects the improvement in adhesion.
[0020]
Furthermore, when the Co content in the surface layer region from the plating surface to a depth of 15 nm was examined, if the content was less than 0.1 atomic%, the effect of improving the initial adhesion was poor, while the Cu content in the surface layer region Since the effect of improving the initial adhesiveness will be saturated if the amount exceeds 1, the range of 0.1 atomic% or more and the Cu content of the surface layer region or less is preferable. More preferably, a range of 0.5 to 5.0 atomic% is recommended.
[0021]
When Co is contained only in the surface layer region from the plating surface to a depth of 15 nm, if ion implantation is used, the Co content gradually decreases from the plating surface in the depth direction as illustrated in FIG. The concentration gradient will be shown. In this case, as described later, the Co content in the surface layer region is a depth profile as shown in FIG. 3 using an X-ray photoelectron spectroscopy (XPS) method, and Cu, Zn, and Co in the entire surface region are formed. Obtained by calculating the Co atomic% amount relative to the total atomic amount. The same applies to the Ni content.
[0022]
Here, the initial adhesiveness is improved by including Co in the surface layer region from the plating surface to a depth of 15 nm. The reason why Co is diffused to the depth of 15 nm from the plating surface is the inside of the plating at the time of vulcanization adhesion. This is because effective diffusion of Cu can be realized. Further, even if Co is diffused during plating in a region exceeding this depth, it is clear that the effect is saturated, resulting in an increase in cost due to an increase in Co.
The above findings were not limited to Co, but were similar to Ni.
[0023]
As described above, the ion implantation technique was used to contain Co in the depth direction from the plating surface. However, when other methods of inserting Co or Ni into the surface layer region of the brass plating were studied, the filament was subjected to the brass plating. For example, after repeating the step of immersing and drying in a colloid in which 5 to 10 parts by weight of a cobalt metal salt and an appropriate surfactant are dispersed with respect to 100 parts by weight of water, heat treatment is performed at a temperature of 150 to 250 ° C. As a result, Co could be diffused to the inside of the plating having a depth of 15 nm. At that time, the cobalt content of the surface layer can be adjusted by controlling at least one of the number of times that the cord is immersed in the liquid, the number of times of drying, and the number of times of thermal diffusion. FIG. 2 shows an example of the result of element quantification using the photoelectron spectroscopic analysis of Cu, Zn, and Co in the plating depth direction of the filaments thus manufactured.
Similarly, when manufacturing a steel cord, an appropriate amount of a metal salt of Co or Ni, which is an adhesion promoter, is added to the lubricant in the filament drawing process, and the heat generated during drawing is used to add Co or Ni. It is also possible to diffuse to the inside of the plating of 15 nm.
[0024]
Next, intensive studies were made on the Cu content on the plating surface. In other words, the basic composition of plating needs to consider the adhesion durability such as heat resistance and moisture resistance after rubber vulcanization in addition to initial adhesion, and from the viewpoint of adhesion durability, the Cu content on the outermost surface Is preferably limited to 45 atomic% or less, more preferably 40 atomic% or less. On the other hand, in order to ensure the initial adhesiveness, it is necessary to contain a certain amount or more of Cu, and the Cu content is 15 atomic% or more, preferably 25 atomic% or more.
[0025]
Incidentally, FIG. 3 shows a typical example of the concentration distribution of each component in the plating depth direction including the plating surface layer region when the basic plating composition and Co content are regulated according to the present invention.
Moreover, it is preferable that Co and Ni contained in the surface layer region are present as oxides in less than 50 atomic% of their total amount. This is because the bond between the metal atom and the oxygen atom is strong, so that the metal oxide itself is stable and, for example, it is difficult to diffuse or move Co or Co ions in the metal. As a result, the exchange reaction or substitution reaction between Co and Cu does not proceed sufficiently, and the role as an adhesion promoter may not be sufficiently achieved.
[0026]
The determination of Co or Ni not included in the oxide contained in the surface layer region is based on the result of measuring the plating surface by X-ray photoelectron spectroscopy, for example, in the schematic diagram of Co spectrum shown in FIG. It can be determined from the abundance ratio between the area ratio of the object and the metal.
[0027]
Furthermore, it is advantageous that the average thickness of the brass plating is 0.13 to 0.30 μm. That is, when the average plating thickness is less than 0.13 μm, the portion where the iron base is exposed increases and the initial adhesion is inhibited, and when it exceeds 0.30 μm, the adhesion reaction proceeds excessively due to heat during use of the rubber article. This is because only brittle adhesion can be obtained.
[0028]
The filament diameter is advantageously 0.40 mm or less. This is because when the thickness exceeds 0.40 mm, when the used rubber article is subjected to repeated strain under bending deformation, the surface strain becomes large and it is easy to cause buckling.
[0029]
Also, the quantitative determination of Co in plating uses X-ray photoelectron spectroscopy to monitor the characteristic photoelectrons of Cu, Zn, Co, O and C from the plating surface to a depth of 15 nm or more in terms of SiO ₂ etching speed. While performing argon etching, the amount of elements present at each depth i was quantified to obtain Cu _i atomic% and Co _i atomic%, respectively, and a depth profile up to 15 nm (see FIG. 3) was created. Co atomic% of the surface layer region was calculated from the relative area of Cu, Zn and Co in the region. The plating thickness is 0.25 μm.
[0030]
Here, Cu _i atomic% and Co _i atomic% are
Cu _i atomic% = [fcu Cu _in / (fcu Cu _in + fznZn _in + fcoCo _in )] × 100
Co _i atomic% = [fco Co _in / (fcuCu _in + fznZn _in + fcoCo _in )] × 100
However, fcu, fzn, fco are sensitivity coefficients of each element, Cu _in , Zn _in , Co _in are count numbers of each element at the position of depth i, and the unit is count per second.
[0031]
In the steel cord manufacturing method according to the present invention, as described above, in addition to ion implantation using a dry technique, a brass plating filament is immersed in a colloid in which a cobalt metal salt and an appropriate surfactant are dispersed and dried. After repeating the process, Co can be diffused into the plating surface layer region by heat treatment at 150 to 250 ° C. The amount of Co can be controlled by the number of times the cord is immersed in the colloidal liquid, the number of times of drying, and the number of times of thermal diffusion. The same applies to Ni.
The tire of the present invention can be filled with an inert gas such as nitrogen in addition to air.
[0032]
【Example】
The present invention will be specifically described.
Each rubber composition (coating rubber) having the composition shown in Table 1 and Table 2 and a rubber-steel cord composite in which a steel cord was embedded were prepared, and the physical properties and adhesive strength of these were measured by the following methods. .
[0033]
(1) Storage elastic modulus E ′ and loss coefficient tanδ
A rubber composition vulcanized under vulcanization conditions [160 ° C. × 14 minutes], using a spectrometer (dynamic viscoelasticity tester) manufactured by Toyo Seiki Co., Ltd., initial load 160 g, frequency 52 Hz, strain 1% Measured at a measurement temperature of 25 ° C. Comparative example 1 was taken as 100 and displayed as an index. A larger numerical value indicates that the elastic modulus of the vulcanized rubber is high and good for E ′, and low exothermic property is good for tan δ.
[0034]
(2) Retention rate of breaking elongation Eb after deterioration For rubber compositions vulcanized under the same vulcanization conditions [160 ° C. × 14 minutes] as described above, EB before deterioration and deterioration conditions [100 ° C. × 24 hours, The EB after being deteriorated by being left in the air was measured according to JIS K6301-1995 (No. 3 test piece), and the retention rate was obtained by the following formula.
Retention rate = 100 × [Eb after deterioration] / [Eb before deterioration]
It shows that deterioration resistance is so high that a numerical value is large.
[0035]
(3) Bloom property after standing for 3 days For a rubber composition vulcanized under the same vulcanization conditions [160 ° C. × 14 minutes] as above, the rubber composition was left for 3 days at 25 ° C. The whiteness caused by the bloom of no matter how much was negligible was judged as “good”, and the one with many white parts was judged as “bad”.
[0036]
(4) Rubber-cord adhesion The following steel-plated steel cords (1 × 5 structure, strand diameter 0.25 mm) are arranged in parallel at intervals of 12.5 mm, and the steel cords are formed with rubber compositions from both sides. A sample was prepared by coating. This is vulcanized under vulcanization conditions [160 ° C. × 10 minutes], and the steel cord is drawn out in accordance with ASTM-D-2229. The surface area of the drawn cord surface covered with rubber The ratio was determined visually. The larger the value, the greater the adhesion and the better.
[0037]
[Table 1]

[0038]
[Table 2]

[0039]
(Appendix)
Transpolybutadiene: (Synthesis method) According to JP-A-11-158207 [0054]. (That is, a 750 ml glass bottle that had been oven dried was sealed with a butyl liner and crown. After the bottle had cooled, 223 grams of a dry butadiene / hexane blend (22.3 wt%) was charged. To this monomer solution was added lanthanum tris [bis (2-ethylhexyl) phosphate] (0.27 mmol) followed by n-BuLi (1.08 mmol) and the bottle was placed in a 65 ° C. water bath. (After 2 hours, the solvent was evaporated to obtain a white powder. The isolated yield was 87%.)
Cobalt salt: Cobalt naphthenate vulcanization accelerator: N, N′-dicyclohexyl-2-benzothiazolylsulfenamide (Noxeller DZ manufactured by Ouchi Shinsei Chemical Co., Ltd.)
Bismaleimide: N, N ′-(4,4′-diphenylmethane) bismaleimide steel cord [conventional product]: Conventional brass plating (Cu 63 wt%, Zn 37 wt%, plating thickness at least 15 nm) is applied. In addition, Cu on the surface is 15 to 45 atomic%.
Steel cord [Invention]: Brass plating having the composition of the present invention is applied. (Cu 63 wt%, Co 0.5 to 5.0 atomic% in the surface layer region, Cu 15 to 45 atomic% in the outermost layer, average thickness of plating 0.13 to 0.3 μm)
Anti-aging agent: N- (1,3-dimethyl-butyl) -N′-phenyl-p-phenylenediamine (Nouchi 6C, manufactured by Ouchi Shinsei Chemical Co., Ltd.)
[0040]
As shown in the table above, the coating rubber blended with bismaleimide has relatively high hardness, low heat build-up, deterioration resistance, appearance and adhesion, and the coating rubber used in combination with transpolybutadiene has high hardness, Adhesion was further improved in the case of a composite with a steel cord having better low heat generation and deterioration resistance and improved plating.
[0041]
【The invention's effect】
As described above, the tire using the rubber-steel cord composite of the present invention increases the hardness of the rubber, and does not impair the low heat build-up, adhesion to the steel cord, and deterioration resistance. A steel cord capable of providing a composition and further improving adhesiveness can be provided, whereby durability of tires such as pneumatic tires for vehicles can be improved.
[Brief description of the drawings]
FIG. 1 is a diagram showing the distribution of Co content in the depth direction from the plating surface to the inside when Co is implanted into the brass plating surface by ion plantation.
FIG. 2 is a diagram showing the distribution of Co content in the depth direction from the plating surface to the inside when Co is thermally diffused inside the plating at 200 ° C. by immersing in a colloid containing a cobalt metal salt and drying.
FIG. 3 is a diagram showing a concentration distribution in the depth direction of each component in brass plating.
FIG. 4 is a schematic diagram of a spectrum when the Co state on the surface of the brass plating is diffracted by X-ray photoelectron spectroscopy.

Claims (8)

A tire using a rubber-steel cord composite composed of a rubber composition in which bismaleimide is blended with a rubber component composed of at least one of natural rubber and diene-based synthetic rubber, and a steel cord,
The rubber composition comprises 0.1 to 5 parts by weight of the bismaleimide with respect to 100 parts by weight of the rubber component,
The bismaleimide is N, N ′-(4,4′-diphenylmethane) bismaleimide ;
The steel cord is a monofilament steel cord made of one of the steel filaments on which the outermost copper concentration is brass-plated with a copper concentration of 15 to 45 atomic%, or a multifilament steel cord formed by twisting these steel filaments. a tire characterized by at.   The tire according to claim 1, wherein the rubber composition is further blended with 0.1 to 15 parts by weight of transpolybutadiene with respect to 100 parts by weight of the rubber component.   The tire according to claim 1 or 2, wherein the rubber component contains 50% by weight or more of natural rubber.   The steel cord has cobalt atoms and nickel in the surface layer region from the surface of the steel filament on which the copper concentration of the outermost layer of the copper plating is 15 to 45 atomic% to the depth of 15 nm inward in the radial direction of the filament. 4. A monofilament steel cord comprising one brass-plated filament containing at least one kind of atoms or a multifilament steel cord formed by twisting these steel filaments. The tire according to claim 1.   The tire according to claim 4, wherein the total amount of cobalt atoms and nickel atoms contained in the surface layer region is 0.1 atomic% or more and not more than the copper atom content in the surface layer region.   The tire according to claim 4 or 5, wherein the total amount of cobalt atoms and nickel atoms contained in the surface layer region is 0.5 to 5.0 atomic%.   The cobalt atom and nickel atom which are not contained in the oxide in the surface layer region are 50 atomic% or more of the total amount of cobalt atom and nickel atom contained in the surface layer region. The tire according to any one of claims. The tire according to any one of claims 1 to 7 , wherein the filament has a diameter of 0.40 mm or less.

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