JPH0653443B2 - Pneumatic tire with improved durability - Google Patents

Pneumatic tire with improved durability

Info

Publication number
JPH0653443B2
JPH0653443B2 JP24184184A JP24184184A JPH0653443B2 JP H0653443 B2 JPH0653443 B2 JP H0653443B2 JP 24184184 A JP24184184 A JP 24184184A JP 24184184 A JP24184184 A JP 24184184A JP H0653443 B2 JPH0653443 B2 JP H0653443B2
Authority
JP
Japan
Prior art keywords
rubber
bead
short fibers
bead wire
pneumatic tire
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
JP24184184A
Other languages
Japanese (ja)
Other versions
JPS61119411A (en
Inventor
雅樹 小川
力 田中
允久 矢萩
隆文 工藤
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bridgestone Corp
Original Assignee
Bridgestone Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bridgestone Corp filed Critical Bridgestone Corp
Priority to JP24184184A priority Critical patent/JPH0653443B2/en
Publication of JPS61119411A publication Critical patent/JPS61119411A/en
Publication of JPH0653443B2 publication Critical patent/JPH0653443B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C15/00—Tyre beads, e.g. ply turn-up or overlap
    • B60C15/0009—Tyre beads, e.g. ply turn-up or overlap features of the carcass terminal portion
    • B60C15/0027—Tyre beads, e.g. ply turn-up or overlap features of the carcass terminal portion with low ply turn-up, i.e. folded around the bead core and terminating at the bead core
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C15/00—Tyre beads, e.g. ply turn-up or overlap
    • B60C15/06—Flipper strips, fillers, or chafing strips and reinforcing layers for the construction of the bead
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C15/00—Tyre beads, e.g. ply turn-up or overlap
    • B60C15/06—Flipper strips, fillers, or chafing strips and reinforcing layers for the construction of the bead
    • B60C15/0603—Flipper strips, fillers, or chafing strips and reinforcing layers for the construction of the bead characterised by features of the bead filler or apex
    • B60C15/0607—Flipper strips, fillers, or chafing strips and reinforcing layers for the construction of the bead characterised by features of the bead filler or apex comprising several parts, e.g. made of different rubbers

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Tires In General (AREA)

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は空気入りタイヤ、例えば、ビードワイヤの回り
をゴムシートで被覆してビードの変形を少なくした耐久
性の改良された空気入りタイヤに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pneumatic tire, for example, a pneumatic tire having a bead wire coated with a rubber sheet to reduce bead deformation and to improve durability.

（従来の技術） 従来の空気入りタイヤのビードの回りは薄いゴムシート
で被覆されているのみであり、加硫時には、ビード部は
ブラダーで押され、かつ、未加硫タイヤの変形のために
カーカスプライからも引きずられる。このため、加硫タ
イヤのビードは未加硫のビードの形状から大きく変形
し、また、ビードの位置が設計目標からずれてしまう。
これにより、タイヤをリム組してもリムとの嵌合に不具
合を生じたり、ビード部の外周部に異常な摩擦摩耗を起
こしたり、特にはチューブレスタイプのタイヤの場合は
空気洩れの原因にもなるという問題点がある。(Prior Art) The conventional bead of a pneumatic tire is only covered with a thin rubber sheet, and at the time of vulcanization, the bead is pushed by a bladder, and due to deformation of the unvulcanized tire. It is also dragged from the carcass ply. Therefore, the bead of the vulcanized tire is largely deformed from the shape of the unvulcanized bead, and the position of the bead deviates from the design target.
As a result, even if the tires are assembled into rims, problems may occur with fitting with the rims, abnormal friction and wear may occur on the outer periphery of the bead, and air leakage may occur especially in the case of tubeless type tires. There is a problem that

従来の空気入りタイヤとしては、例えば、第３図に示す
ようなものがある。第３図において、31は従来の空気入
りタイヤであり、空気入りタイヤ31はビードワイヤ32を
有するビード部33と、ビード部33で折り返され、ビード
ワイヤ32に係止されたカーカスプライ35と、カーカスプ
ライ35の外周部に位置するベルト36と、ベルト36の外周
部に位置するトレッド37とを有している。ビード部33の
ビードワイヤ32は未加硫時は六角形状であるが加硫時の
加圧加熱のために、六角形が大きく変形しているという
問題点がある。Conventional pneumatic tires include, for example, those shown in FIG. In FIG. 3, 31 is a conventional pneumatic tire. The pneumatic tire 31 includes a bead portion 33 having a bead wire 32, a carcass ply 35 folded back by the bead portion 33 and locked to the bead wire 32, and a carcass ply. The belt 36 is located on the outer peripheral portion of the belt 35, and the tread 37 is located on the outer peripheral portion of the belt 36. The bead wire 32 of the bead portion 33 has a hexagonal shape when unvulcanized, but there is a problem that the hexagonal shape is greatly deformed due to pressure heating during vulcanization.

（発明の目的） そこで、本発明は、上記欠点を改良するため、ミクロな
短繊維を含む短繊維補強ゴム組成物を充分に配向させ、
しかも短繊維の配向方向を有するゴムでビード回りを被
覆して、加硫時のゴムの流れを極力抑えてビードの形状
およびビードの配置位置を加硫後に設計の通りになるよ
うにして、ビード部の耐久性の改良された空気入りタイ
ヤを提供することを目的とする。(Object of the invention) Therefore, in order to improve the above-mentioned drawbacks, the present invention sufficiently orients a short fiber reinforced rubber composition containing micro short fibers,
Moreover, by covering the bead area with rubber having the orientation direction of the short fibers, the flow of rubber during vulcanization is suppressed as much as possible so that the bead shape and bead arrangement position are as designed after vulcanization. An object of the present invention is to provide a pneumatic tire with improved durability of the part.

（発明の構成） 本発明に係る耐久性の改良された空気入りタイヤは、ビ
ード部に位置するビードワイヤと、多数のコードが平行
に配置されたゴム引きコード層から成り、両端部がビー
ド部で折り返してビードワイヤに係止されたカーカスプ
ライとビードワイヤの放射方向外面に配置されたスティ
フナーと、を有する空気入りタイヤにおいて、ビードワ
イヤとビードワイヤの周囲にあるスティフナーおよびカ
ーカスプライとの間に平均径１μｍ以下、平均長さＬと
平均径Ｄの比（Ｌ／Ｄ）が８以上である短繊維を５重量
部以上含有するゴム組成物から成るゴム補強層を備え、
該ゴム補強層の短繊維が、アミド基を有する熱可塑性ポ
リマーから成っており、フェノールホルムアルデヒド系
の縮合物を介してゴムの部分とグラフトしていることを
特徴とする。また、前記ゴム補強層の短繊維の配向方向
とビードワイヤの配列方向が同じであることが好まし
い。(Structure of the Invention) A pneumatic tire with improved durability according to the present invention comprises a bead wire located at a bead portion and a rubberized cord layer in which a large number of cords are arranged in parallel, and both end portions are bead portions. In a pneumatic tire having a carcass ply folded back and locked to the bead wire and a stiffener arranged on the radial outer surface of the bead wire, an average diameter of 1 μm or less between the bead wire and the stiffener around the bead wire and the carcass ply, A rubber reinforcing layer made of a rubber composition containing 5 parts by weight or more of short fibers having a ratio (L / D) of average length L and average diameter D of 8 or more,
The short fibers of the rubber-reinforcing layer are made of a thermoplastic polymer having an amide group, and are grafted with a rubber portion via a phenol-formaldehyde-type condensate. Further, it is preferable that the orientation direction of the short fibers of the rubber reinforcing layer and the arrangement direction of the bead wires are the same.

本発明において、短繊維の平均径を１μｍ以下に限定し
たのは、次のような理由による。本来、短繊維に歪（応
力）がかかった場合、短繊維の両末端に大きな剪断応力
がかかり、その剪断応力によって、短繊維の両末端から
亀裂が発生、成長して短繊維補強ゴム組成物に特有の大
きなクリープを生じる傾向が強かった。その剪断応力
は、短繊維の形状に大きく依存していることが分かって
おり、当然のことながら短繊維が小さければ小さい程、
短繊維の両末端にかかる歪も小さくなるので剪断愛力も
小さくなる。短繊維が小さくなれば短繊維１個当たりの
補強効果も小さくなるが個数が多くなるので全体として
見れば、短繊維が入ることによって耐疲労性、特に繰り
返し歪を受けた後のクリープが大きくなるのを防ぐこと
ができる。さらにまた、短繊維補強の目的である高い弾
性率、優れた耐カット性、および本発明に利用している
高い異方性を発現させることが出来るのである。In the present invention, the reason why the average diameter of the short fibers is limited to 1 μm or less is as follows. Originally, when strain (stress) is applied to the short fibers, large shear stress is applied to both ends of the short fibers, and the shear stress causes cracks from both ends of the short fibers to grow and grow. There was a strong tendency to generate large creep peculiar to. It has been found that the shear stress greatly depends on the shape of the short fibers, and as a matter of course, the smaller the short fibers,
Since the strain applied to both ends of the short fiber is also small, the shear force is also small. The smaller the short fibers, the smaller the reinforcing effect per short fiber, but the larger the number. Therefore, when viewed as a whole, the short fibers will increase fatigue resistance, especially creep after repeated strain. Can be prevented. Furthermore, the high elastic modulus, the excellent cut resistance, and the high anisotropy utilized in the present invention, which are the purpose of reinforcing short fibers, can be exhibited.

前記の短繊維補強のメリットを出せるためには、アスペ
クト比（Ｌ／Ｄ）が８以上であることが必要であり、こ
のアスペクト比を８以上に保って短繊維の両末端にかか
る剪断応力を問題にならないレベルまで下げるには、短
繊維の平均径を１μｍ以下にしなければならない。In order to take advantage of the above-mentioned short fiber reinforcement, it is necessary that the aspect ratio (L / D) is 8 or more. Keeping this aspect ratio at 8 or more, the shear stress applied to both ends of the short fiber is In order to reduce it to a level that does not cause a problem, the average diameter of the short fibers must be 1 μm or less.

本発明に於いて、短繊維の量を５重量部以上に限定した
理由は、５重量部よりも少ないと本発明の目的である短
繊維補強の効果が期待出来ないからである。本発明で
は、後述するように短繊維を極力配向させ、その配向方
向とビードワイヤの方向と同じにすることによって、ゴ
ム流れの少ないタイヤを得ることが可能となる。In the present invention, the reason why the amount of short fibers is limited to 5 parts by weight or more is that if the amount is less than 5 parts by weight, the effect of reinforcing short fibers, which is the object of the present invention, cannot be expected. In the present invention, as described later, by orienting the short fibers as much as possible and making the orientation direction the same as the bead wire direction, it is possible to obtain a tire with less rubber flow.

本発明に於いて、ビードワイヤの配列方向と短繊維補強
ゴム中の短繊維の配向方向とは同じとするのが好ましい
が、これは同じとした方が短繊維補強の効果が最も発揮
出来るからである。In the present invention, it is preferable that the arrangement direction of the bead wires and the orientation direction of the short fibers in the short fiber reinforced rubber are the same, but this is the same because the effect of the short fiber reinforcement can be most exerted. is there.

本発明に於いては、加硫後の短繊維補強ゴムに於いて短
繊維の配列方向に引っ張った50％歪時の弾性率Ｍ１と、
短繊維の配列方向と直角の方向に引っ張った50％歪時の
弾性率Ｍ２の比（Ｍ１／Ｍ２）が2.5 以上であることが
好ましいが、このことは短繊維の配向の程度を示してお
り、この程度に配向させた短繊維を含有する短繊維補強
ゴム組成物を前述したようにビードワイヤの配列方向と
短繊維補強ゴム中の短繊維の配列方向とは同じ方向にし
た時に最も大きな効果を生み出す。In the present invention, in the vulcanized short fiber reinforced rubber, the elastic modulus M1 at 50% strain when pulled in the direction of arrangement of short fibers,
It is preferable that the ratio (M1 / M2) of the elastic modulus M2 at 50% strain when pulled in the direction perpendicular to the arrangement direction of the short fibers is 2.5 or more, which indicates the degree of orientation of the short fibers. As described above, when the short fiber reinforced rubber composition containing the short fibers oriented in this degree is arranged in the same direction as the bead wire arranging direction and the short fiber arranging direction in the short fiber reinforced rubber, the greatest effect is obtained. produce.

本発明に於いて、前記短繊維の材料を、アミド基を有す
る熱可塑性ポリマーに限定した理由は、アミド基を有す
るポリマーが結晶し易く、かつ結晶の配向が比較的容易
で球晶等を作り難いので短繊維の耐疲労性が優れている
為である。また、アミド基を有するポリマーの結晶融点
は通常200 ℃以上であり、耐熱性の点からも問題がない
からである。さらに、補強ゴム層の短繊維とゴムの部分
がフェノールホルムアルデヒド系の縮合物を介してグラ
フトしていることを限定した理由は、短繊維とゴム部分
との接着強度を増加させることによって短繊維補強ゴム
の耐疲労性を向上させることができるからである。In the present invention, the reason for limiting the material of the short fibers to the thermoplastic polymer having an amide group is that the polymer having an amide group is easy to crystallize, and the orientation of the crystal is relatively easy to form spherulites. This is because the short fibers have excellent fatigue resistance because they are difficult. Also, the crystal melting point of the polymer having an amide group is usually 200 ° C. or higher, and there is no problem in terms of heat resistance. Furthermore, the reason why the short fiber and rubber portion of the reinforcing rubber layer are limited to be grafted through a phenol-formaldehyde-based condensate is that the short fiber reinforced by increasing the adhesive strength between the short fiber and the rubber portion. This is because the fatigue resistance of rubber can be improved.

以下、実施例でより詳細に説明する。Hereinafter, the present invention will be described in more detail.

（実施例１） 実施例１では本発明の空気入りタイヤが従来のタイヤに
比べて、耐久性に於いて著しく改良されていることを示
す。(Example 1) Example 1 shows that the pneumatic tire of the present invention is remarkably improved in durability as compared with the conventional tire.

(1) 強化ゴム組成物の製法 温度、150 ℃でロータの回転数、100rpmに調節したＯＯ
Ｃバンバリーミキサー（神戸製鋼製）の中に、100 ℃の
ムーニー粘度が25である天然ゴム1400g、及びＮ−（３
−メタクリロイルオキシ−２−ヒドロキシプロピル）−
Ｎ′−フェニル−Ｐ−フェニレンジアミン〔ノクラック
Ｇ−１、大内新興製〕14gを投入し、１分間素練した。
次いで、６−ナイロン（商品名：１０３０Ｂ、宇部興産
（株）製、融点221 ℃、分子量30000)700gを投入し、７
分間混練りした。この間にバンバリーミキサー内の温度
は232 ℃まで上昇し、６−ナイロンは溶融した。次い
で、ノボラック型フェノールホルムアルデヒド初期縮合
物（明和化成（株）製、商品名５５０ＰＬ）30ｇを投入
し、７分間混練りした後、ヘキサメチレンテトラミン３
ｇを投入し、2.5 分間混練りして（この間バンバリーミ
キサーの打身の温度は230 ℃）グラフト反応させた後、
バンバリーミキサーの下方に落下し取り出した。(1) Manufacturing method of reinforced rubber composition OO adjusted to 100 rpm, temperature of rotor at 150 ° C
In a C Banbury mixer (made by Kobe Steel), 1400 g of natural rubber having a Mooney viscosity of 25 at 100 ° C and N- (3
-Methacryloyloxy-2-hydroxypropyl)-
14 g of N'-phenyl-P-phenylenediamine (Nocrac G-1, Ouchi Shinko Co., Ltd.) was added and the mixture was masticated for 1 minute.
Then, 700 g of 6-nylon (trade name: 1030B, manufactured by Ube Industries, Ltd., melting point 221 ° C., molecular weight 30,000) was added, and 7
Kneaded for minutes. During this time, the temperature in the Banbury mixer rose to 232 ° C and the 6-nylon melted. Next, 30 g of novolac-type phenol formaldehyde initial condensate (manufactured by Meiwa Kasei Co., Ltd., trade name: 550PL) was added, and after kneading for 7 minutes, hexamethylenetetramine 3
g, and kneading for 2.5 minutes (while the temperature at the batter of the Banbury mixer was 230 ° C) for a graft reaction,
It fell below the Banbury mixer and was taken out.

次いで、得られた混練り物は、ノズルの内径２mm、長さ
と内径との比（Ｌ／Ｄ）が２の円形ダイを有する30mmφ
押出機（池貝社製）を用いて、ダイ設定温度235 ℃で紐
状に押出し、押出物を０℃冷却水で冷却固化し、つい
で、ガイドロールを経てボビンにドラフト比９で35ｍ／
分の速度で巻き取った。この巻取物を一昼夜室温で真空
乾燥し、付着水を除いた後、この巻き取り物約500 本を
束ねてシート状（厚さ２mm、巾150 mm）として、このシ
ート状物をロール間隙0.2 mm、温度60℃の一対の圧延ロ
ールで約10倍にロール圧延して、短繊維で強化した強化
ゴム組成物（試料１）を得た。Then, the obtained kneaded product has a circular die having an inner diameter of the nozzle of 2 mm and a ratio of the length to the inner diameter (L / D) of 30 mmφ.
Using an extruder (made by Ikegai Co., Ltd.), it was extruded into a string shape at a die set temperature of 235 ° C., the extrudate was cooled and solidified with 0 ° C. cooling water, and then 35 m / with a draft ratio of 9 on a bobbin via a guide roll.
It was wound up at a speed of a minute. After vacuum-drying this roll for 24 hours at room temperature to remove water that has adhered, about 500 rolls are bundled into a sheet (thickness 2 mm, width 150 mm) and the roll gap 0.2 A pair of rolling rolls having a temperature of 60 ° C. and a roll diameter of about 10 times was used to obtain a reinforced rubber composition (Sample 1) reinforced with short fibers.

(2) 短繊維補強ゴムおよびゴム補強層の製法 前記の強化ゴム組成物は表１に示すような配合成分と配
合比率で配合され、温度70℃、ロータの回転数70r.p.m
に調節したＯＣＣバンバリーミキサー（神戸製鋼製）で
混練りして短繊維補強ゴムより成るガム組成物１を作成
した。また、比較のために、強化ゴム組成物を含まない
配合成分と配合比率を用い、他は同じ製法によってゴム
組成物２およびゴム組成物３を作成した。さらにこれら
のゴム組成物１乃至ゴム組成物３は通常のゴムロールを
用いて所定の厚さのゴムシートから成るゴム補強層に作
成された。ゴム組成物１は短繊維を所定量だけ含有して
いるのでゴムロールの引出し方向に短繊維が配向した本
発明のゴム補強層ができる。(2) Manufacturing method of short fiber reinforced rubber and rubber reinforced layer The above-mentioned reinforced rubber composition is compounded in a compounding ratio and a compounding ratio as shown in Table 1, a temperature of 70 ° C., a rotational speed of a rotor of 70 rpm.
A gum composition 1 composed of short fiber reinforced rubber was prepared by kneading with an OCC Banbury mixer (manufactured by Kobe Steel) adjusted to. For comparison, rubber composition 2 and rubber composition 3 were prepared by the same manufacturing method except that the compounding components and the compounding ratio not containing the reinforced rubber composition were used. Further, these rubber compositions 1 to 3 were formed on a rubber reinforcing layer made of a rubber sheet having a predetermined thickness by using a normal rubber roll. Since the rubber composition 1 contains a predetermined amount of short fibers, the rubber reinforcing layer of the present invention in which the short fibers are oriented in the drawing direction of the rubber roll can be obtained.

（ａ）液状ＩＲはクラレイソプレンケミカル（株）製Ｌ
ＩＲ−50である。 (A) Liquid IR is L manufactured by Kuraray Isoprene Chemical Co., Ltd.
IR-50.

（ｂ）ノボラック型カシュー変性フェノール樹脂はフェ
ノール100 重量部に対してカシュー油40重量部で変性し
たノボラック型フェノール樹脂である。(B) The novolac type cashew-modified phenolic resin is a novolac type phenolic resin modified with 40 parts by weight of cashew oil to 100 parts by weight of phenol.

（ｃ）老化防止剤は大内新興化学工業（株）製ノクラッ
ク810 −ＮＡである。(C) Anti-aging agent is Nocrac 810-NA manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

（ｄ）Ｎｏｂｓは大内新興化学工業（株）製ノクセラー
ＭＳＡ−Ｇである。(D) Nobs is Nox Cellar MSA-G manufactured by Ouchi Shinko Chemical Co., Ltd.

（ｅ）短繊維の量（重量部）は試料１の中の短繊維の量
をゴム組成中のゴム、100 重量部当りに含まれている短
繊維の量で示したものである。(E) The amount of short fibers (parts by weight) is the amount of short fibers in Sample 1 expressed by the amount of short fibers contained per 100 parts by weight of rubber in the rubber composition.

(3) タイヤの構造 以下、本発明の実施例を図面に基づいて説明する。(3) Tire Structure Hereinafter, embodiments of the present invention will be described with reference to the drawings.

第１図および第２図は本発明の空気入りタイヤを示す図
である。1 and 2 are views showing the pneumatic tire of the present invention.

まず、構成を説明すると、本発明に係る空気入りタイヤ
１は第２図に示すようにビード部２に位置するビードワ
イヤ３と、多数のコードが平行に配置されたゴム引きコ
ード層から成り、両端部５ａがビード部２で折り返して
ビードワイヤ３に係止されたカーカスプライ５と、ビー
ドワイヤ３の放射方向外面に愛知されたスティフナー６
とを有する。ビードワイヤ３とビードワイヤ３の周囲に
あるスティフナー６との間およびビードワイヤ３とカー
カスプライ５との間にはゴム補強層７が設けられる。こ
のゴム補強層７は平均径１μｍ以下、平均長さＬと平均
径Ｄの引（Ｌ／Ｄ）が８以上である短繊維を５重量部以
上含有するゴム組成物からなっている。ゴム補強層の短
繊維の配向方向とビードワイヤ３の配列方向（すなわ
ち、円周方向）は同じである。また、ゴム補強層の短繊
維はアミド基を有する熱可塑性ポリマーから成ってお
り、ゴムの部分とフェノールホルムアルデヒド系の縮合
物を介してグラフトしている。First, the structure will be described. A pneumatic tire 1 according to the present invention comprises a bead wire 3 located in a bead portion 2 and a rubberized cord layer in which a large number of cords are arranged in parallel as shown in FIG. The carcass ply 5 in which the portion 5a is folded back at the bead portion 2 and is locked to the bead wire 3 and the stiffener 6 which is known to the outer surface in the radial direction of the bead wire 3
Have and. A rubber reinforcing layer 7 is provided between the bead wire 3 and the stiffener 6 around the bead wire 3 and between the bead wire 3 and the carcass ply 5. The rubber reinforcing layer 7 is made of a rubber composition containing 5 parts by weight or more of short fibers having an average diameter of 1 μm or less and an average length L and average diameter D (L / D) of 8 or more. The orientation direction of the short fibers of the rubber reinforcing layer and the arrangement direction of the bead wires 3 (that is, the circumferential direction) are the same. The short fibers of the rubber-reinforcing layer are made of a thermoplastic polymer having an amide group, and are grafted with the rubber portion through a phenol-formaldehyde-based condensate.

(4) タイヤの製造と性能試験結果（作用） タイヤの製造は通常の方法によって行われた、即ち、未
加硫の部材としてビードワイヤ３と、スティフナー６、
ゴム引きコード層（カーカスプライ５）、４層のベルト
層、トレッド、サイドウォールおよび短繊維を含有し、
所定の量配向した所定厚さ（例えば0.2 〜3.0mm ）のゴ
ムシートからなるゴム補強層を準備する。次いで、ゴム
補強層はビードワイヤ３を中心にして、その周囲に所定
の厚さでビードワイヤの全円周に亘って張り付け径20mm
の円形状のゴム補強層を有するビードとした。次いで、
これら準備された部材は所定のタイヤ成形機を用いて、
所定の順序で、張り付けて所謂グリーンケースを製造す
る。次いで、加硫機中で加圧、加熱して加硫された製品
タイヤ（実施例１）を製造する。(4) Manufacture of tire and results of performance test (function) Manufacture of a tire was carried out by a usual method, that is, a bead wire 3 as an unvulcanized member, a stiffener 6,
Rubberized cord layer (carcass ply 5), containing four belt layers, tread, sidewalls and short fibers,
A rubber reinforcing layer made of a rubber sheet having a predetermined thickness (for example, 0.2 to 3.0 mm) oriented in a predetermined amount is prepared. Then, the rubber reinforcing layer is attached to the bead wire 3 with a predetermined thickness around the bead wire 3 over the entire circumference of the bead wire with a diameter of 20 mm.
And a bead having a circular rubber reinforcing layer. Then
These prepared members use a predetermined tire molding machine,
The so-called green case is manufactured by pasting in a predetermined order. Next, a product tire (Example 1) vulcanized by pressurizing and heating in a vulcanizer is manufactured.

この際、グリーンケースは加硫機の中で加圧、加熱され
るが、グリーンケースの外径はタイヤモールドの外径よ
りわずかに小さい、また、グリーンケースはタイヤの放
射内側から加圧され、タイヤの内側およびタイヤモール
ドの高温により加熱される。これによりグリーンケース
のゴムが軟化し、かつグリーンケースの外径が大きくな
るように変形する。この際、ビード部においては、ビー
ドワイヤ３の周囲のカーカスプライ５がタイヤの外側よ
り内側に僅か移動し、ビードワイヤを変形しようとする
力が加わる。しかしながら、ビードワイヤの周囲には、
本発明の短繊維がビードワイヤの配列方向に配向したゴ
ム補強層が所定の厚さで設けられている。したがって、
ビードワイヤを変形しようとする応力は異方性を有する
ゴム補強層の内部およびその近傍のゴムで緩和され、か
つこれらの剪断歪は緩和される。このため、ビードワイ
ヤの変形および近傍の変形も極めて僅かとなり、設計目
標通りのビード部形状を有する空気入りタイヤができ
る。タイヤサイズは295 ／75R 22.5のチューブレスラジ
アルタイヤである。At this time, the green case is pressurized and heated in the vulcanizer, the outer diameter of the green case is slightly smaller than the outer diameter of the tire mold, and the green case is pressurized from the inner side of the tire radiating, It is heated by the high temperature inside the tire and in the tire mold. This softens the rubber of the green case and deforms it so that the outer diameter of the green case increases. At this time, in the bead portion, the carcass ply 5 around the bead wire 3 slightly moves inward from the outer side of the tire, and a force to deform the bead wire is applied. However, around the bead wire,
The rubber reinforcing layer in which the short fibers of the present invention are oriented in the bead wire arranging direction is provided with a predetermined thickness. Therefore,
The stress that tends to deform the bead wire is relaxed by the rubber inside the rubber reinforcing layer having anisotropy and in the vicinity thereof, and these shear strains are relaxed. For this reason, the deformation of the bead wire and the deformation in the vicinity become extremely small, and a pneumatic tire having a bead portion shape as designed can be obtained. Tire size is 295 / 75R 22.5 tubeless radial tire.

また、短繊維を含有しないゴムシート層を用いて、実施
例１の場合と同様にして比較例のタイヤを製造する。Further, a tire of a comparative example is manufactured in the same manner as in Example 1 using a rubber sheet layer containing no short fiber.

これらの実施例および比較例のタイヤは所定の方向でビ
ード耐久試験（表２中にビード耐久テストとして示して
ある）され、かつ解剖試験（表２中に形状の乱れとして
示している）が実施された（以下、この２つの試験を単
に、性能試験という）。The tires of these examples and comparative examples were subjected to a bead endurance test (shown as bead endurance test in Table 2) and an anatomical test (shown as shape disorder in Table 2) in a predetermined direction. (Hereinafter, these two tests are simply referred to as performance tests).

ここに、ビード耐久試験は通常のドラム試験機を用い
て、内圧10kg/cm2、JIS 180％荷重の条件でドラム上を
走行させ、ビード部に故障が発生してタイヤが破壊する
までの走行距離数で評価した。また、解剖試験は所定の
方法で解剖し、ゴム補強層を有するビードおよびその近
傍の形状が設計通りになっているか否かを試験した。試
験結果は表２に示されている。表２において、有はビー
ドが変形していることを示し、（大）および（中）はそ
れぞれビードの変形が大きいおよび中位を意味している
ことを示している。Here, the bead durability test was run on a drum using an ordinary drum tester under the conditions of internal pressure of 10 kg / cm 2 and JIS 180% load, until the bead failure occurred and the tire was destroyed. It was evaluated by the number of distances. In the dissection test, dissection was performed by a predetermined method, and it was tested whether or not the shape of the bead having the rubber reinforcing layer and the vicinity thereof were as designed. The test results are shown in Table 2. In Table 2, "Yes" indicates that the bead is deformed, and "Large" and "Medium" indicate that the bead is large and medium, respectively.

表２において、実施例１は、形状の乱れもなく、かつ、
ビード耐久試験は29,700kmで比較例１、２とは極めて大
幅に優れている結果を示している。In Table 2, in Example 1, the shape was not disturbed, and
The bead durability test was 29,700 km, which is extremely superior to Comparative Examples 1 and 2.

以上説明したことから、本発明に係る空気入りタイヤが
従来のタイヤに比較してビード回りのゴムの剪断歪が小
さくなりビードの形状およびビードの配置位置の変化が
小さくなり、ビード部の耐久性が極めて大幅に改良され
ているかがわかる。From what has been described above, the pneumatic tire according to the present invention has a smaller shear strain of the rubber around the bead as compared with the conventional tire, the change in the bead shape and the bead arrangement position is reduced, and the durability of the bead portion is reduced. It can be seen that is greatly improved.

（実施例２〜４） 実施例２〜４では本発明に使用する短繊維の平均径が１
μｍ以下に限定されることを示す。 (Examples 2 to 4) In Examples 2 to 4, the average diameter of the short fibers used in the present invention is 1
It is shown that the thickness is limited to μm or less.

前述の強化ゴム組成物（試料１）の製法に準じで使用す
るナイロン樹脂の粉末の平均粒径を変えた強化ゴム組成
物（試料２〜６）が製造された。試料１〜６の短繊維の
平均径と物性を表４に示してある。Reinforced rubber compositions (Samples 2 to 6) were produced in which the average particle diameter of the nylon resin powder used was changed according to the method for producing the reinforced rubber composition (Sample 1) described above. Table 4 shows the average diameter and physical properties of the short fibers of Samples 1 to 6.

（ａ）グラフト率の測定及び算出は下記によって行っ
た。 (A) The graft ratio was measured and calculated as follows.

実施例１で得られた強化ゴム組成物２ｇをベンゼン200
ｍｌの中に室温で添加し、強化ゴム組成物中のゴム分を
溶解させ、得られたスラリーを室温で遠心分離して溶液
部分と沈澱部分とに分けた。沈澱部分について前記の操
作を７回繰り返し行った後、沈澱部分を乾燥してナイロ
ン繊維を得た。このナイロ繊維をフェノールとオルソジ
クロルベンゼンの１：３（重量比）の混合溶媒に溶解さ
せ、水素原子核Ｈを用いいる核磁気共鳴スペクトル（Ｎ
ＭＲ）で分析（内部標準：テトラメチルシラン）し、Ｎ
ＭＲチャートから天然ゴムに起因するメチル基及びメチ
レン基、６−ナイロンに起因するＣＯ基に隣接したメチ
レン基、ＮＨ基に隣接したメチレン基及び他の３個のメ
チレン基の各々のピークについて、切取り面積法により
６−ナイロンと天然ゴムとのモル比を求めて、グラフト
率を算出した。また前記のナイロン繊維の形状を繊維約
200 本について１万倍の倍率で走査型電子顕微鏡を用い
て測定した。繊維は断面が円形の極めて細い短繊維であ
った。試料３は短繊維の平均径が1.1 μｍで本発明の平
均形の限界１μｍを超えたものであるまた、表４によっ
て得られた強化ゴム組成物（試料２〜６）を用いて、
（実施例１〜５）の(2)短繊維補強ゴムおよびゴムシー
ト層の製法に準じでゴム組成物４〜８を製造し、さら
に、各ゴム組成物を用いて、それぞれ補強層を製造し
た。ここに、ゴム組成物４〜８の配合成分は表５に示さ
れており、ゴム組成物５は、試料３を用いており、短繊
維の平均形1.0 μｍ超えたゴム組成物である。2 g of the reinforced rubber composition obtained in Example 1 was added to benzene 200
The rubber component in the reinforced rubber composition was dissolved in the mixture at room temperature, and the resulting slurry was centrifuged at room temperature to separate into a solution part and a precipitation part. The above operation was repeated 7 times for the precipitated portion, and then the precipitated portion was dried to obtain a nylon fiber. The Nilo fiber was dissolved in a mixed solvent of phenol and orthodichlorobenzene in a ratio of 1: 3 (weight ratio), and a nuclear magnetic resonance spectrum (N
MR) (internal standard: tetramethylsilane), N
From the MR chart, cut out the respective peaks of the methyl group and methylene group derived from natural rubber, the methylene group adjacent to the CO group derived from 6-nylon, the methylene group adjacent to the NH group and the other three methylene groups. The graft ratio was calculated by obtaining the molar ratio of 6-nylon and natural rubber by the area method. In addition, the shape of the nylon fiber
200 pieces were measured with a scanning electron microscope at a magnification of 10,000 times. The fibers were very fine short fibers with a circular cross section. Sample 3 had an average diameter of the short fibers of 1.1 μm and exceeded the limit of the average shape of the present invention of 1 μm. Further, using the reinforced rubber composition (Samples 2 to 6) obtained according to Table 4,
Rubber compositions 4 to 8 were produced according to the method for producing (2) short fiber reinforced rubber and rubber sheet layer in (Examples 1 to 5), and further, a reinforcing layer was produced using each rubber composition. . Here, the compounding ingredients of the rubber compositions 4 to 8 are shown in Table 5, and the rubber composition 5 uses the sample 3 and is a rubber composition in which the average form of the short fibers exceeds 1.0 μm.

次に、表６に示すように、前述のゴム組成物４〜８の補
強層を用いて、実施例２〜４および比較例５、６のタイ
ヤが前述した（実施例１）のタイヤ製造に準じて製造さ
れ、次いで、性能試験が実施された。性能試験結果が表
６に示されている。Next, as shown in Table 6, the tires of Examples 2 to 4 and Comparative Examples 5 and 6 were manufactured by using the reinforcing layers of the rubber compositions 4 to 8 described above to manufacture the tire of Example 1 described above. It was manufactured according to the above, and then a performance test was performed. The performance test results are shown in Table 6.

表６に於いて、実施例２〜４は共に短繊維の平均形１μ
ｍ以下の表４中の試料２、試料４および試料６を用いて
おり、このタイヤの性能試験の結果は極めて良い結果を
示している。In Table 6, Examples 2 to 4 are both short fibers having an average shape of 1 μm.
m, sample 4, sample 4 and sample 6 in Table 4 below are used, and the results of the performance test of this tire show extremely good results.

一方、比較例３のタイヤはゴム組成物に短繊維の平均径
が1.0 μｍを超えたゴム組成物５を用いており、性能試
験の結果は走行距離が低く、かつ形状の乱れもあり短繊
維補強ゴムの効果が小さい。すなわち、短繊維の平均径
が１μｍを超えるとゴムの補強効果が少ない。以上説明
したことから、短繊維の平均径は１μｍ以下に限定され
る。On the other hand, the tire of Comparative Example 3 uses the rubber composition 5 in which the average diameter of the short fibers is more than 1.0 μm, and the performance test results show that the running distance is short and the shape is disordered. The effect of reinforcing rubber is small. That is, when the average diameter of the short fibers exceeds 1 μm, the rubber reinforcing effect is small. From the above description, the average diameter of the short fibers is limited to 1 μm or less.

また、比較例４のタイヤには、表４の試料５が用いられ
ており、短繊維の平均径は0.2 μｍであり、１μｍ以下
ではあるが、アスペクト比は7.8 のものが用いられてい
る。この場合、表６の比較例４の補強効果が十分でな
い。このことから、短繊維のアスペクト比（Ｌ／Ｄ）は
８以上であることが必要である。For the tire of Comparative Example 4, Sample 5 in Table 4 was used, and the average diameter of the short fibers was 0.2 μm, which was 1 μm or less, but the aspect ratio was 7.8. In this case, the reinforcing effect of Comparative Example 4 in Table 6 is not sufficient. From this, the aspect ratio (L / D) of the short fibers needs to be 8 or more.

（実施例５、６） 実施例５、６では、短繊維補強ゴム中の短繊維の量が５
重量部以上に限定されることを示す。 (Examples 5 and 6) In Examples 5 and 6, the amount of short fibers in the short fiber reinforced rubber was 5.
It means that it is limited to more than parts by weight.

短繊維補強ゴム中の短繊維の量が５重量部以上になるよ
う、前述の強化ゴム組成物（試料１）を用い、かつ、表
７の配合成分によって、実施例１と同様にゴム組成物９
〜11が製造された。短繊維の量（重量部）はゴム組成物
９では３、ゴム組成物10および11では、それぞれ５、20
重量部である。これらゴム組成物を用いて、ビードバン
ドルの直径18mmのものを造り他は実施例１と同様にし
て、表８の実施例５、６および比較例５、６のタイヤが
実施例１と同様にして製造された。比較例５、６のタイ
ヤはゴムの流れが大きく形状の乱れもあり、かつ、耐久
試験の結果も極めて悪い。このことから、短繊維の量は
５重量部以上が必要であることがわかる。A rubber composition was used in the same manner as in Example 1 except that the above-mentioned reinforced rubber composition (Sample 1) was used so that the amount of the short fibers in the short fiber reinforced rubber was 5 parts by weight or more, and the blending components in Table 7 9
~ 11 were produced. The amount (parts by weight) of short fibers was 3 for the rubber composition 9 and 5, 20 for the rubber compositions 10 and 11, respectively.
Parts by weight. Using these rubber compositions, a bead bundle having a diameter of 18 mm was produced in the same manner as in Example 1 except that the tires of Examples 5 and 6 and Comparative Examples 5 and 6 in Table 8 were the same as in Example 1. Manufactured. The tires of Comparative Examples 5 and 6 had a large flow of rubber and had irregular shapes, and the results of the durability test were extremely poor. From this, it is understood that the amount of the short fibers needs to be 5 parts by weight or more.

なお、特開昭５７−１０６３２号公報で開示されるｉｓ
ｏ−ポリプロピレン短繊維を本発明の本質的要件の「高
い異方性」を出すようにアレンジすれば充分に使用可能
である。又、特公昭５７−４５２７号公報、特公昭５７
−４５３０号公報、特公昭５７−３０６６２号公報で開
示されたｓｙｎ−１、２−ポリブタジエン短繊維につい
ても同様に使用可能である。しかしながら、最も好まし
いのは、本発明に用いたナイロン短繊維である。 The is disclosed in Japanese Patent Laid-Open No. 57-10632
The o-polypropylene short fibers can be sufficiently used by arranging them so as to exhibit the "high anisotropy" which is an essential requirement of the present invention. In addition, Japanese Examined Patent Publication No. 57-4527 and Japanese Examined Patent Publication 57
The syn-1,2-polybutadiene short fibers disclosed in JP-B-4530 and JP-B-57-30662 can also be used in the same manner. However, most preferred are the nylon staple fibers used in the present invention.

また、本発明は前記実施例によって縛られるものではな
く、有機繊維をベルトに使用したラジアルタイヤ、ベル
トを有したバイアスタイヤ（ベルテッドバイアスタイ
ヤ）およびバイアスタイヤ等に使用可能であるし、乗用
車用タイヤのみならず、大型タイヤにもまた適用可能で
ある。Further, the present invention is not limited to the above-mentioned examples, and can be used for radial tires using organic fibers for belts, bias tires having belts (belted bias tires) and bias tires, and passenger vehicle tires. Not only is it applicable to large tires.

（発明の効果） 以上説明したように、本発明によれば、結晶し易くかつ
結晶配向が比較的容易で球晶等を作り難いアミド基を有
する熱可塑性ポリマーからなるミクロな短繊維をフェノ
ールホルムアルデヒド系樹脂の縮合物を介してゴム部分
とグラフトするようにした短繊維補強ゴム組成物を、ビ
ードワイヤの周囲とスティフナーおよびカーカスプライ
との間にゴム補強層として配置しているので、補強ゴム
層の耐疲労性を十分に確保しつつ、加硫時のゴムの変化
を極めて少なくしてビードの形状およびビードの配置位
置を加硫後に設計の通りになるようにできる。また、こ
の短繊維補強ゴムと通常のコーティングゴムを組合わせ
ることにより相乗効果的にビードワイヤの周囲の変化も
少なくするという効果があり、これらの効果によりタイ
ヤの耐久性能を著しく改良した空気入りタイヤを提供す
ることができる。(Effects of the Invention) As described above, according to the present invention, a micro short fiber made of a thermoplastic polymer having an amide group that is easy to crystallize, has a relatively easy crystal orientation, and is hard to form a spherulite is used as a phenol formaldehyde. A short fiber reinforced rubber composition that is designed to be grafted with a rubber portion via a condensate of a system resin is arranged as a rubber reinforcing layer between the periphery of the bead wire and the stiffener and carcass ply. It is possible to make the shape of the bead and the position of the bead as designed after vulcanization by sufficiently reducing the change of rubber during vulcanization while ensuring sufficient fatigue resistance. In addition, the combination of this short fiber reinforced rubber and ordinary coating rubber has the effect of synergistically reducing the change in the circumference of the bead wire, and by these effects a pneumatic tire with significantly improved tire durability performance can be obtained. Can be provided.

【図面の簡単な説明】[Brief description of drawings]

第１、２図は本発明に係る空気入りタイヤの一実施例を
示すものであり、第１図はその断面図、第２図はビード
部の一部拡大断面図である。第３図は従来の空気入りタ
イヤの断面図である。 １……空気入りタイヤ、 ２……ビード部、 ３……ビードワイヤ、 ５……カーカスプライ、 ５ａ……両端部、 ６……スティフナー、 ７……ゴム補強層。1 and 2 show an embodiment of a pneumatic tire according to the present invention, FIG. 1 is a sectional view thereof, and FIG. 2 is a partially enlarged sectional view of a bead portion. FIG. 3 is a sectional view of a conventional pneumatic tire. 1 ... Pneumatic tire, 2 ... Bead part, 3 ... Bead wire, 5 ... Carcass ply, 5a ... Both ends, 6 ... Stiffener, 7 ... Rubber reinforcement layer.

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】ビード部に位置するビードワイヤと、多数
のコードが平行に配置されたゴム引きコード層から成
り、両端部がビード部で折り返してビードワイヤに係止
されたカーカスプライと、ビードワイヤの放射方向外面
に配置されたスティフナーと、を有する空気入りタイヤ
において、ビードワイヤとビードワイヤの周囲にあるス
ティフナーおよびカーカスプライとの間に平均径１μｍ
以下、平均長さＬと平均径Ｄの比（Ｌ／Ｄ）が８以上で
ある短繊維を５重量部以上含有するゴム組成物から成る
ゴム補強層を備え、該ゴム補強層の短繊維が、アミド基
を有する熱可塑性ポリマーから成っており、フェノール
ホルムアルデヒド系の縮合物を介してゴムの部分とグラ
フトしていることを特徴とする耐久性の改良された空気
入りタイヤ。1. A carcass ply comprising a bead wire located at a bead portion and a rubberized cord layer in which a large number of cords are arranged in parallel, both ends being folded back at the bead portion and locked to the bead wire, and radiation of the bead wire. In a pneumatic tire having a stiffener disposed on the outer surface in the direction of the arrow, the average diameter between the bead wire and the stiffener around the bead wire and the carcass ply is 1 μm.
Hereinafter, a rubber reinforcing layer made of a rubber composition containing 5 parts by weight or more of short fibers having a ratio (L / D) of the average length L to the average diameter D of 8 or more is provided, and the short fibers of the rubber reinforcing layer are A pneumatic tire having improved durability, which is made of a thermoplastic polymer having an amide group and is grafted with a rubber portion via a phenol-formaldehyde-type condensate. 【請求項２】前記ゴム補強層の短繊維の配向方向とビー
ドワイヤの配列方向が同じであることを特徴とする特許
請求の範囲第１項記載の耐久性の改良された空気入りタ
イヤ。2. A pneumatic tire with improved durability according to claim 1, wherein the orientation direction of the short fibers of the rubber reinforcing layer and the arrangement direction of the bead wires are the same.
JP24184184A 1984-11-16 1984-11-16 Pneumatic tire with improved durability Expired - Fee Related JPH0653443B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP24184184A JPH0653443B2 (en) 1984-11-16 1984-11-16 Pneumatic tire with improved durability

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP24184184A JPH0653443B2 (en) 1984-11-16 1984-11-16 Pneumatic tire with improved durability

Publications (2)

Publication Number Publication Date
JPS61119411A JPS61119411A (en) 1986-06-06
JPH0653443B2 true JPH0653443B2 (en) 1994-07-20

Family

ID=17080294

Family Applications (1)

Application Number Title Priority Date Filing Date
JP24184184A Expired - Fee Related JPH0653443B2 (en) 1984-11-16 1984-11-16 Pneumatic tire with improved durability

Country Status (1)

Country Link
JP (1) JPH0653443B2 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3422694B2 (en) * 1998-09-17 2003-06-30 住友ゴム工業株式会社 Heavy duty tire
JP2001310606A (en) * 2000-04-26 2001-11-06 Bridgestone Corp Pneumatic tire
JP5319736B2 (en) * 2011-06-15 2013-10-16 東洋ゴム工業株式会社 Pneumatic radial tire

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3122015A1 (en) * 1981-06-03 1982-12-30 Bayer Ag, 5090 Leverkusen VEHICLE TIRES WITH SPECIAL REINFORCEMENT OF THE BELT AND THE TIRE FOOT
DE3132941A1 (en) * 1981-08-20 1983-03-03 Bayer Ag, 5090 Leverkusen HIGHLY DURABLE VEHICLE TIRE

Also Published As

Publication number Publication date
JPS61119411A (en) 1986-06-06

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