JPH0319802B2 - - Google Patents
Info
- Publication number
- JPH0319802B2 JPH0319802B2 JP56124751A JP12475181A JPH0319802B2 JP H0319802 B2 JPH0319802 B2 JP H0319802B2 JP 56124751 A JP56124751 A JP 56124751A JP 12475181 A JP12475181 A JP 12475181A JP H0319802 B2 JPH0319802 B2 JP H0319802B2
- Authority
- JP
- Japan
- Prior art keywords
- rubber
- weight
- parts
- tire
- tread
- 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 - Lifetime
Links
- 229920001971 elastomer Polymers 0.000 claims description 92
- 239000005060 rubber Substances 0.000 claims description 92
- 239000000203 mixture Substances 0.000 claims description 23
- 230000003712 anti-aging effect Effects 0.000 claims description 21
- 239000003795 chemical substances by application Substances 0.000 claims description 20
- 244000043261 Hevea brasiliensis Species 0.000 claims description 15
- 229920003052 natural elastomer Polymers 0.000 claims description 15
- 229920001194 natural rubber Polymers 0.000 claims description 15
- CBCKQZAAMUWICA-UHFFFAOYSA-N 1,4-phenylenediamine Chemical compound NC1=CC=C(N)C=C1 CBCKQZAAMUWICA-UHFFFAOYSA-N 0.000 claims description 13
- 229920003048 styrene butadiene rubber Polymers 0.000 claims description 13
- 239000011324 bead Substances 0.000 claims description 12
- 239000006229 carbon black Substances 0.000 claims description 8
- 229920002857 polybutadiene Polymers 0.000 claims description 6
- 239000005062 Polybutadiene Substances 0.000 description 13
- 239000002174 Styrene-butadiene Substances 0.000 description 10
- 230000007423 decrease Effects 0.000 description 10
- 238000005452 bending Methods 0.000 description 9
- 238000010586 diagram Methods 0.000 description 9
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 7
- 238000005299 abrasion Methods 0.000 description 7
- 238000005259 measurement Methods 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 6
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 5
- 230000006835 compression Effects 0.000 description 5
- 238000007906 compression Methods 0.000 description 5
- 238000004073 vulcanization Methods 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- ZNRLMGFXSPUZNR-UHFFFAOYSA-N 2,2,4-trimethyl-1h-quinoline Chemical compound C1=CC=C2C(C)=CC(C)(C)NC2=C1 ZNRLMGFXSPUZNR-UHFFFAOYSA-N 0.000 description 2
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 239000000853 adhesive Substances 0.000 description 2
- 239000003963 antioxidant agent Substances 0.000 description 2
- 230000003078 antioxidant effect Effects 0.000 description 2
- 239000000470 constituent Substances 0.000 description 2
- 229910052740 iodine Inorganic materials 0.000 description 2
- 239000011630 iodine Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- QAZLUNIWYYOJPC-UHFFFAOYSA-M sulfenamide Chemical compound [Cl-].COC1=C(C)C=[N+]2C3=NC4=CC=C(OC)C=C4N3SCC2=C1C QAZLUNIWYYOJPC-UHFFFAOYSA-M 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 150000003557 thiazoles Chemical class 0.000 description 2
- GFEZQRWDLTZHAT-UHFFFAOYSA-N 1-n,4-n-bis(4-methylpentan-2-yl)benzene-1,4-diamine Chemical compound CC(C)CC(C)NC1=CC=C(NC(C)CC(C)C)C=C1 GFEZQRWDLTZHAT-UHFFFAOYSA-N 0.000 description 1
- 239000004606 Fillers/Extenders Substances 0.000 description 1
- UTGQNNCQYDRXCH-UHFFFAOYSA-N N,N'-diphenyl-1,4-phenylenediamine Chemical compound C=1C=C(NC=2C=CC=CC=2)C=CC=1NC1=CC=CC=C1 UTGQNNCQYDRXCH-UHFFFAOYSA-N 0.000 description 1
- OUBMGJOQLXMSNT-UHFFFAOYSA-N N-isopropyl-N'-phenyl-p-phenylenediamine Chemical compound C1=CC(NC(C)C)=CC=C1NC1=CC=CC=C1 OUBMGJOQLXMSNT-UHFFFAOYSA-N 0.000 description 1
- 206010040844 Skin exfoliation Diseases 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 230000005489 elastic deformation Effects 0.000 description 1
- DECIPOUIJURFOJ-UHFFFAOYSA-N ethoxyquin Chemical compound N1C(C)(C)C=C(C)C2=CC(OCC)=CC=C21 DECIPOUIJURFOJ-UHFFFAOYSA-N 0.000 description 1
- 235000019285 ethoxyquin Nutrition 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- -1 paraphenylenediamine compound Chemical class 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 150000004986 phenylenediamines Chemical class 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000010058 rubber compounding Methods 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 238000005987 sulfurization reaction Methods 0.000 description 1
- 239000004636 vulcanized rubber Substances 0.000 description 1
- 239000001993 wax Substances 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
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
- B60C13/00—Tyre sidewalls; Protecting, decorating, marking, or the like, thereof
- B60C13/002—Protection against exterior elements
-
- 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
- B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
- B60C1/0025—Compositions of the sidewalls
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Tires In General (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Description
本発明は空気入りタイヤに関し、さらに詳しく
は、タイヤ表面に沿つて、シヨルダー部からサイ
ドウオール部の上方にわたる構造及びその組成を
改良することにより、耐動的疲労性、耐候性等を
向上したトラツク・バス用空気入りタイヤに関す
るものである。
従来トラツク、バス用等大型タイヤのラジアル
方向断面構造は、第１図に示すように、キヤツプ
トレツド部Ａのゴム１がシヨルダー部Ｃ附近にお
いて、サイドウオール部Ｂのゴム２の上にかぶさ
るよう構成されたいわゆるキヤツプ・オーバー・
サイド構造のタイヤと、第２図に示すように、サ
イドウオール部Ｂのゴム２が、タイヤの踏面側端
ａの近傍まで伸びているいわゆるサイド・オーバ
ー・キヤツプ構造のタイヤがある。
ところがタイヤにおいてシヨルダー部Ｃからサ
イドウオール部Ｂの上方にわたる部分は、走行時
において繰返し圧縮変形を最も厳しく受ける部分
であると共に日光の影響を受ける部分でもある関
係上、耐屈曲疲労性、耐候性、耐摩耗性等に優れ
たゴム組成物が用いられることが望ましい。
しかしながらこのシヨルダー部Ｃからサイドウ
オール部Ｂの上方にわたる部分は、実際には上述
したようにキヤツプトレツド部Ａのゴム１かある
いはサイドウオール部Ｂのゴム２によつて構成さ
れている。
そもそもキヤツプトレツド部Ａのゴム１には、
キヤツプトレツドとしての機能すなわち耐摩耗
性、耐カツトチツプ性を附与することに重点をお
いた組成物が使用されており、このゴム１に前述
したようにシヨルダー部Ｃに必要な機能、すなわ
ち耐屈曲疲労性や耐候性をも兼備させるために
は、例えばパラフエニレンジアミン系老化防止剤
を多量に配合しなければならず、高コストになる
等の問題がある。またサイドウオール部Ｂのゴム
２も、サイドウオール部Ｂが受ける伸張変形に適
したゴム組成物からなつており、このゴム２にシ
ヨルダー部Ｃが受ける圧縮変形に適した成分を配
合したり耐屈曲疲労性や耐候性を附与するのはや
はり経済性等の面で問題があるのが現状である。
本発明の目的は、上述の各問題点を解消し、耐
動的疲労性や耐候性等を向上し得る優れたトラツ
ク・バス用空気入りタイヤを提供せんとすること
にある。
そしてその特徴とするところは、ゴム成分とし
て天然ゴムとポリブタジエンゴムを特定量含有
し、老化防止剤としてパラフエニレンジアミン系
化合物を多量含有する耐屈曲疲労性、耐候性、耐
摩耗性に優れたゴム組成物からなる厚さ0.5〜５
mmのゴムシートを、踏面接地端部ａからビード端
部ｂ方向に約１〜10mm下方の位置から幅50〜150
mmにわたつて、少なくとも踏面ゴムとサイドウオ
ールゴムとの接合部を覆うと共に、タイヤの表面
に沿つてタイヤ周方向に配置することにより、従
来キヤツプトレツド部のゴム及びサイドウオール
部のゴムに兼備させていたシヨルダー部附近の機
能を独立せしめて、より効果的に走行時に繰り返
し圧縮変形を最も厳しく受け、しかも踏面ゴムと
サイドウオールゴムとの接合部を有するシヨルダ
ー部付近の耐屈曲疲労性、耐候性及び耐摩耗性を
向上する一方、キヤツプトレツド部のゴム及びサ
イドウオール部のゴムの各組成を、それぞれの必
要機能に合わせて最適化し、併せてタイヤ構成材
料コストの低減を図り得るようにした点にある。
以下本発明を実施例により図面を参照しつつ詳
細に説明する。
第３図ａ，ｂはそれぞれ本発明の実施例からな
るトラツク・バス用空気入りタイヤのラジアル方
向断面説明図、第４図は前記ゴムシート（以下、
シートと略す）の肉厚と老化防止剤残存率との関
係を示す屋外曝露試験結果を示す図、第５図は走
行時においてタイヤの接地面端部からビード部に
至る各部分が受ける主せん断歪の測定結果を示す
図、第６図は走行時においてタイヤの接地面端部
からビード部に至る各部分が受ける主歪の測定結
果を示す図、第７図は走行時、回転するタイヤの
踏面接地点（0゜）からタイヤ周方向円周上におけ
るタイヤ踏面部の接線方向の歪の変動を示す図で
ある。
第３図ａ，ｂにおいて１はキヤツプトレツド部
Ａのゴム、２はサイドウオール部Ｂのゴム、３は
シートであつて、タイヤＴの表面に沿つてシヨル
ダー部Ｃからサイドウオール部Ｂの上方にわたり
タイヤ円周方向に配置されている。４はベースゴ
ム、５はビード、６はビードフイラー、７はカー
カス、ａはタイヤＴの踏面端部、ｂはタイヤＴの
ビード端部をそれぞれ示している。そして上述し
たシート３は、40〜70重量部の天然ゴムと30〜60
重量部のポリブタジエンゴムとを含有するゴム
100重量部に対し、パラフエニレンジアミン系老
化防止剤２〜12重量部及びカーボンブラツク40〜
70重量部を配合したゴム組成物、あるいは40〜70
重量部の天然ゴムと30〜60重量部のポリブタジエ
ンゴムと30重量部以下のスチレン・ブタジエン共
重合ゴムとを含有するゴム100重量部に対し、パ
ラフエニレンジアミン系老化防止剤２〜12重量部
及びカーボンブラツク40〜70重量部を配合したゴ
ム組成物からなる厚さ0.5〜５mmのシートにより
構成されている。
本発明においては、第３図ａに示すように、ゴ
ムシート３の端部３ａをタイヤＴの踏面接地端部
ａからビード端部ｂ方向に約１〜10mm下方の位置
に配置することにより、タイヤの接地時のゴムシ
ートの早期摩耗を防止することができる。また、
ゴムシート３をタイヤＴの踏面接地端部ａからビ
ード端部ｂ方向に約１〜10mm下方の位置から巾50
mm〜150mmにわたつて被覆することにより、踏面
ゴムとサイドウオールゴムとの接合部を覆い、か
つトラツク・バス用タイヤが最も厳しい繰り返し
圧縮変形を受ける領域を被覆することができる。
なお、第３図ｂに示すように、タイヤのシヨル
ダー部Ｃが丸味を帯びて形成されている場合の前
記踏面端部ａの位置は、次のようにして求めるこ
とができる。すなわち、まずタイヤトレツド半径
の中心Ｏを中心とし、半径をOHとして描いた円
の延長と、タイヤ最大巾Ｗより中心線OHにおろ
した垂線の足Ｐを中心とし、半径をPWとして描
いた円の延長との交点a′と、トレツド半径の中心
Ｏを結ぶ線a′Oがタイヤと交わる点をａとする。
そして、このシート３は、前述したようにタイ
ヤの走行による繰返し圧縮変形を最も厳しく受
け、しかも踏面ゴムとサイドウオールゴムとの接
合部を覆う位置に設けられるので、耐屈曲疲労
性、耐候性、耐摩耗性に優れたゴム組成物が用い
られねばならず、そのためには、ゴムとしては高
い引張強さとを有する天然ゴム（NR）と、耐繰
返し圧縮疲労性、特にタイヤ側壁上部の受けやす
い10Hz前後の繰返し圧縮に対する抵抗性ならびに
耐摩耗性に優れたポリブタジエンゴム（BR）を
組合わせるのがよい。NRとBRの組合わせによ
り、シート３としての機能を発揮できるが、これ
にスチレン・ブタジエン共重合ゴム（SBR）を
さらに加えると、カツト傷の発生を抑えることが
できる。また側壁上部、すなわちサイドウオール
部Ｂの上部には10％以下の低歪の伸長変形もかか
るので、耐伸長変形にすぐれたSBRの存在はさ
らに好ましい。
NRは、ゴム全量100重量部のうち40〜70重量
部がよい。これは40重量部未満ではシート３の引
張強さ、引裂強さが充分発揮できず、70重量部を
超えると、その分BRの配合量が減つて、BRの
特徴である耐圧縮疲労性、耐摩耗性が発揮できな
くなるからである。
BRは30重量部以上60重量部未満がよい。これ
はBRの配合量が60重量部以上になると、引張強
さ、引裂強さが低下するからである。
SBRの配合量は30重量部以下とするのが望ま
しい。これは30重量部を超えて配合すると、
NR、BRの配合量が減つて上記のNR、BRの特
徴が発揮できなくなり、SBRの配合量としては
17〜25重量部が好ましい。
次に、シート３の配合に最も重要なのは適切な
老化防止剤である。タイヤ側壁部は日光の照射を
受けることと、走行中に激しい繰返し圧縮変形を
受けるので、これらの影響によりサーカムクラツ
ク、オゾンクラツクが発生しやすい。そこでシー
ト３にはパラフエニレンジアミン系老化防止剤を
タイヤの他の部分より多量に配合することが好ま
しい。
本発明において、上記パラフエニレンジアミン
系老化防止剤の配合量は、ゴム100重量部に対し
４〜10重量部の範囲である。４重量部未満では、
前述の日光照射や繰り返し圧縮変形によるクラツ
クの発生を防止する効果が十分に発揮されない。
また、10重量部を超えて配合しても前記効果はそ
れほど大きくならないからである。このシート３
を設けることにより、通常あまり日光の影響を受
けないキヤツプトレツド部Ａはパラフエニレンジ
アミン系老化防止剤の配合量をゴム100重量部に
対し３重量部以下に抑えることが出来るので、経
済的である。また、日光の影響を受けるタイヤ側
壁すなわちサイドウオール部Ｂの中央〜下部のゴ
ム配合でも、パラフエニレンジアミン系の老化防
止剤は２〜７重量部に抑えることができると共
に、耐伸長変形にすぐれたSBR中心の配合とす
ることができる。
本発明において用いるパラフエニレンジアミン
系（以下ｐ−フエニレンジアミン系）老化防止剤
は、たとえばＮ，N′−ジフエニル−ｐ−フエニ
レンジアミン、Ｎ−フエニル−N′−イソプロピ
ル−ｐ−フエニレンジアミン、Ｎ−フエニル−
N′−１，３−ジメチルブチル−ｐ−フエニレン
ジアミン、Ｎ，N′−ビス（１，３−ジメチルブ
チル）−ｐ−フエニレンジアミン、Ｎ，N′−ビス
−２−ナフチル−ｐ−フエニレンジアミンなどの
中から任意に選択できる。
本発明のシート３においてはｐ−フエニレンジ
アミン系に加えて他の老化防止剤、たとえば２，
２，４−トリメチル−１，２−ジヒドロキノリン
重合体（RD）、６−エトキシ−２，２，４−ト
リメチル−１，２−ジヒドロキノリン等を適宜配
合できる。カーボンブラツクは、ゴム100重量部
に対し40〜70重量部、好ましくは45〜65重量部が
良い。これは耐摩耗性を維持するためカーボン量
は40重量部以上が必要で、70重量部以上の場合混
合加工性を維持するためオイルを多量に加えなけ
ればならず、おのずと引張強さ等物性の低下を来
たし、耐オゾン性も低下する。ここに用いるカー
ボンの種類としては、よう素吸着量が35mg／ｇ以
上でDBP吸油量が70ml／100ｇ以上のものを単独
又は２種以上ブレンドで用いるが、よう素吸着量
が80mg／ｇ以上のものをカーボンブラツク全使用
量の25％以上用いることが耐摩耗性に有効であ
る。
また、ゴム組成物に必要なイオウ、加硫促進
剤、促進助剤などは適量配合するが、その中でも
促進剤は選択することが望ましい。このシートに
は老化防止剤を非常に多く配合するので、スコー
チが早くなる恐れがあり、これを防止するためチ
アゾール類の中でもスルフエンアミド系のものが
適しており、スルフエンアミド系加硫促進剤を
0.5〜1.5重量部の範囲で配合すればスコーチの問
題もなく、モジユラスなど物性上最適なものが得
られる。
またシート３の厚さについては、前記の如く高
価な老化防止剤を多量に配合するため、可能な限
り薄いことが、経済上好ましい。しかし、あまり
薄くすると老化防止剤が表面に析出（Ieaching現
象）したり、隣接ゴム層へ移行して急激に濃度低
下を起こし、効果がなくなる。
なお、本発明において、キヤツプトレツドゴム
としては通常の耐摩耗性、耐カツトチツプ性等に
優れたゴム組成物が使用され、サイドウオールゴ
ムとしては通常の耐屈曲疲労性、低転動抵抗性に
優れたゴム組成物が使用され、特に限定されるも
のではない。
本発明者らは、シートと踏面部ゴムのラミネー
ト体のゲージ比率を変えトータル10mmになるよう
にサンプルを作成し、それを12ケ月間屋外曝露し
た後各サンプルのシート部の老化防止剤の定量分
析を行なつた。なお、試験片は後述の実施例４の
配合のゴムと、比較例６の配合のゴムを貼り合わ
せ、加硫接着して作成した。
この結果は第４図に示すように、厚さ0.5mm未
満では老化防止剤の残存率が低下する。したがつ
てシートの厚さは0.5mm以上であることが必要で
あるが、上限としては経済性を考えれば５mmが上
限となる。また幅はシヨルダー上部の接地端付近
から踏面ゴムとサイドウオールゴムの接合部を覆
つて配置するのが良く、したがつて、タイヤ接地
面端ａから、ビード端ｂへ向かつて1/3〜1/2を覆
う巾であることが好ましく、トラツク、バス用タ
イヤにおいては50〜150mmであることが望ましい。
シート３の貼り付け方法については、このシート
３がタイヤの前記の位置に配置されるような方法
であればどのような方法であつてもよいのである
が、タイヤの未加硫時に貼り付けるのがよい。
加硫後では特殊な接着剤が必要となり、しかも
大型タイヤの過酷な使用条件下では剥離するおそ
れがある。従つて未加硫時であればどの工程で貼
り合わせても差支えないのであるが、タイヤの組
み立て成型時に行なうことは実際の作業能率低下
をもたらし、しかも貼合わせるゴム同士が、押出
し後時間を経て、温度低下し、粘着性が下つてい
るので未加硫ゴムとしての自着性が発揮し難くな
る。これに対し、接地部と側壁部のゴム２と、シ
ート３を１体押し出しと同時にこのシートを貼り
合わせるならば、作業能率も良好でシートゴム３
とキヤツプトレツド部のゴム１との接着を良好な
ものが得られる。
つづいて、タイヤ各部が受ける歪について述べ
る。
第５図はタイヤＴの表面が、その接地点上にお
いて受けるせん断歪を測定したものである。タイ
ヤのサイドウオール部Ｂの上部から、踏面端部に
かけて、特に本発明シートの貼付される位置にせ
ん断歪のピークがあることがわかる。タイヤサイ
ズ1000−20、空気圧6.75Kg／cm2、負荷2700Kg、π
ゲージメータにより測定した。
第６図は、第５図のせん断歪を周方向成分と断
面方向成分に、また圧縮歪と伸長歪とに分解して
示した図である。断面方向に、特にシヨルダー部
Ｃに圧縮歪の大きなピークがあり、側壁中〜下部
には、周方向に伸長歪がかかつていることがわか
る。
第７図はタイヤの接地点（0゜とする）からの周
方向への角度（距離）と、各角度におけるタイヤ
踏面部接線方向への歪との関係を示した図であ
る。タイヤ接点地点（0゜）では周方向に伸長歪
が、接地点より15〜20゜はなれた点では圧縮歪が
かかつているのがわかる。この図により、タイヤ
回転中に圧縮歪と伸長歪がくり返しかかることが
わかる。第６，７図は、サイズ、空気圧、負荷等
の条件を第５図と同じにして測定したものであ
る。
次に、実施例により本発明をさらに詳しく説明
する。
実験例 １
表１にはNR、BR、SBRを組み合わせ、酸化
亜鉛、ステアリン酸、カーボンブラツク、老化防
止剤、ワツクス、伸展油を小型バンバリーで混練
し、ロールにてイオウ、加硫促進剤を混練し148
℃で30分加熱により加硫した。そのうち本発明に
関連のある特性を示した。この結果からNRと
BRの組合わせが70：30又は55：45までは各特性
とも満足し得るが、40：60の如くBRを過半数組
合わせると圧縮疲労性は良いが引裂力及び耐カツ
ト性低下が著るしく、好ましくない。また耐カツ
ト性の付与にはゴム100％のうちSBRを10〜30重
量％混入するとよい。SBRが30％を超えると圧
縮疲労性が著るしく低下する。
以上のことからNRはBRとのブレンドの場合
55重量％以上が最適でBRは40％前後が良い。ま
たSBRとの３者ブレンドの場合NRのうち10〜20
重量％の範囲をSBRにおきかえれば全ての特性
を満足し最適であることがわかつた。
なお、耐カツト性試験には落下式カツト試験機
（ギロチンカツトとも云う）を用いた。本機は加
硫ゴムサンプルに15〜25cmの高さから一定荷重の
刃を落下させ、その刃の進入深さを測定すること
により耐カツト性を評価するものである。
実験例 ２
表２にはカーボンブラツクの種類及び老防（Ｓ
−13）の量について検討した結果を示す。カーボ
ンのグレードは側壁部の耐摩耗性附与の必要性か
らN770では満足せず、前記範囲が限定される。
また、ｐ−フエニレンジアミン系老化防止剤Ｓ−
13の量は、ゴム100重量部に対し４重量部未満で
は耐オゾン性が低下する。同表に比較例として踏
面部ゴム（比較例６）と一般側壁部ゴム（比較例
７）を示した。これから明らかなように、踏面部
（キヤツプトレツド部用）ゴム１と側壁部（サイ
ドウオール部用）ゴム２は耐圧縮疲労性が劣り、
さらに踏面部の耐オゾン性が著るしく劣ることが
わかる。また該部コンパウンドのモジユラスは
300％変形時80〜120Kg／cm2が適当であるが、側壁
上部は踏面部用ゴム１の上にシート３を貼り合わ
せる構造なので耐屈曲疲労性の点で300％モジユ
ラスが80〜90Kg／cm2の範囲が好ましい。
The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire that has improved dynamic fatigue resistance, weather resistance, etc. by improving the structure and composition of the tire from the shoulder section to the upper sidewall section along the tire surface. This relates to pneumatic tires for buses. Conventionally, the radial cross-sectional structure of large tires for trucks, buses, etc. is constructed such that the rubber 1 of the cap tread portion A covers the rubber 2 of the sidewall portion B in the vicinity of the shoulder portion C, as shown in Fig. 1. So-called cap over
There are tires with a side structure and tires with a so-called side-over-cap structure in which the rubber 2 of the sidewall portion B extends to the vicinity of the tread side edge a of the tire, as shown in FIG. However, in a tire, the part extending from the shoulder part C to the upper part of the sidewall part B is the part that is most severely subjected to repeated compressive deformation during driving, and is also the part that is affected by sunlight, so it has poor bending fatigue resistance, weather resistance, It is desirable to use a rubber composition with excellent wear resistance. However, the portion extending from the shoulder portion C to the upper side of the sidewall portion B is actually constituted by the rubber 1 of the cap lead portion A or the rubber 2 of the sidewall portion B, as described above. In the first place, the rubber 1 of the cap lead part A is
A composition is used that focuses on providing functions as a cap lead, that is, wear resistance and cut chip resistance, and as mentioned above, this rubber 1 has the functions necessary for the shoulder portion C, that is, bending fatigue resistance. In order to have both properties and weather resistance, for example, a large amount of a paraphenylenediamine anti-aging agent must be added, which poses problems such as high cost. Further, the rubber 2 of the sidewall portion B is also made of a rubber composition suitable for the elongation deformation that the sidewall portion B undergoes, and this rubber 2 is blended with components suitable for the compressive deformation that the shoulder portion C is subjected to, or is made of a rubber composition suitable for the elastic deformation that the sidewall portion B undergoes. At present, imparting fatigue resistance and weather resistance is problematic in terms of economic efficiency. An object of the present invention is to provide an excellent pneumatic tire for trucks and buses that can solve the above-mentioned problems and improve dynamic fatigue resistance, weather resistance, etc. Its features include specific amounts of natural rubber and polybutadiene rubber as rubber components, and a large amount of paraphenylenediamine compound as an anti-aging agent, which has excellent bending fatigue resistance, weather resistance, and abrasion resistance. Thickness 0.5-5 made of rubber composition
mm rubber sheet from a position approximately 1 to 10 mm downward in the direction from the tread end a to the bead end b.
mm, covering at least the joint between the tread rubber and the sidewall rubber, and by placing it along the tire surface in the circumferential direction of the tire. By making the functions near the shoulder part independent, we can more effectively improve the bending fatigue resistance, weather resistance, and resistance of the shoulder part, which is subject to the most severe repeated compressive deformation during driving, and which has the joint between the tread rubber and the sidewall rubber. While improving abrasion resistance, the composition of the rubber in the cap tread and sidewall parts has been optimized to suit the required functions of each, making it possible to reduce the cost of tire constituent materials. . Hereinafter, the present invention will be explained in detail by way of examples with reference to the drawings. 3a and 3b are explanatory radial cross-sectional views of pneumatic tires for trucks and buses according to embodiments of the present invention, and FIG. 4 is an illustration of the rubber sheet (hereinafter referred to as
Figure 5 shows the results of an outdoor exposure test showing the relationship between the wall thickness of the tire (abbreviated as "sheet") and the residual rate of anti-aging agent. Figure 6 is a diagram showing the measurement results of strain. Figure 6 is a diagram showing the measurement results of the principal strain experienced by each part of the tire from the edge of the contact patch to the bead when the tire is running. FIG. 3 is a diagram showing a variation in strain in the tangential direction of the tire tread portion on the circumference in the tire circumferential direction from the tread surface point (0°). In FIGS. 3a and 3b, 1 is the rubber of the cap lead part A, 2 is the rubber of the sidewall part B, and 3 is a sheet that extends from the shoulder part C to the upper side of the sidewall part B along the surface of the tire T. arranged circumferentially. 4 is a base rubber, 5 is a bead, 6 is a bead filler, 7 is a carcass, a is a tread end of the tire T, and b is a bead end of the tire T, respectively. The above-mentioned sheet 3 contains 40 to 70 parts by weight of natural rubber and 30 to 60 parts by weight of natural rubber.
Rubber containing parts by weight of polybutadiene rubber
Per 100 parts by weight, 2 to 12 parts by weight of paraphenylenediamine antioxidant and 40 to 40 parts by weight of carbon black.
A rubber composition containing 70 parts by weight, or 40 to 70 parts by weight.
2 to 12 parts by weight of paraphenylene diamine anti-aging agent per 100 parts by weight of rubber containing 30 to 60 parts by weight of polybutadiene rubber, and 30 parts by weight or less of styrene-butadiene copolymer rubber. The sheet is made of a rubber composition containing 40 to 70 parts by weight of carbon black and has a thickness of 0.5 to 5 mm. In the present invention, as shown in FIG. 3a, by arranging the end 3a of the rubber sheet 3 at a position approximately 1 to 10 mm below the tread end a of the tire T in the direction of the bead end b. , it is possible to prevent early wear of the rubber sheet when the tire touches the ground. Also,
Rub the rubber sheet 3 from a position approximately 1 to 10 mm downward from the tread end a of the tire T in the direction of the bead end b to a width of 50 mm.
By coating over a range of mm to 150 mm, it is possible to cover the joint between the tread rubber and the sidewall rubber, and also to cover the area where the truck/bus tire undergoes the most severe repeated compressive deformation. In addition, as shown in FIG. 3b, when the shoulder portion C of the tire is formed rounded, the position of the tread end a can be determined as follows. That is, first, the extension of a circle drawn with the center O of the tire tread radius as the center and the radius as OH, and the extension of a circle drawn with the center as the foot P of the perpendicular drawn from the tire maximum width W to the center line OH and the radius as PW. Let a be the point where a line a'O connecting the intersection a' with the extension and the center O of the tread radius intersects the tire. As mentioned above, this sheet 3 is provided in a position that is most severely subjected to repeated compressive deformation due to tire running, and also covers the joint between the tread rubber and the sidewall rubber, so it has excellent bending fatigue resistance, weather resistance, A rubber composition with excellent abrasion resistance must be used, and for this purpose, natural rubber (NR), which has high tensile strength as a rubber, and cyclic compression fatigue resistance, especially at 10 Hz, which is easily affected by the upper part of the tire sidewall, must be used. It is best to combine polybutadiene rubber (BR), which has excellent resistance to repeated compression back and forth and abrasion resistance. The combination of NR and BR can perform the function of sheet 3, but if styrene-butadiene copolymer rubber (SBR) is further added to this, the occurrence of cut scratches can be suppressed. Further, since the upper part of the side wall, that is, the upper part of the side wall portion B is subjected to elongation deformation with a low strain of 10% or less, the presence of SBR, which has excellent resistance to elongation deformation, is more preferable. NR is preferably 40 to 70 parts by weight out of 100 parts by weight of the total rubber. This is because if it is less than 40 parts by weight, the tensile strength and tear strength of the sheet 3 cannot be fully demonstrated, and if it exceeds 70 parts by weight, the blended amount of BR will be reduced by that amount, and the compressive fatigue resistance, which is a characteristic of BR, will be reduced. This is because wear resistance cannot be exhibited. BR is preferably 30 parts by weight or more and less than 60 parts by weight. This is because when the blending amount of BR exceeds 60 parts by weight, the tensile strength and tear strength decrease. It is desirable that the amount of SBR added is 30 parts by weight or less. If this is added in excess of 30 parts by weight,
As the blended amount of NR and BR decreases, the characteristics of NR and BR mentioned above cannot be exhibited, and the blended amount of SBR decreases.
17 to 25 parts by weight is preferred. Next, the most important factor in the formulation of Sheet 3 is a suitable anti-aging agent. The side wall of the tire is exposed to sunlight and subjected to severe repeated compressive deformation during driving, and these effects tend to cause circumferential cracks and ozone cracks. Therefore, it is preferable that the sheet 3 contains a larger amount of paraphenylenediamine anti-aging agent than other parts of the tire. In the present invention, the amount of the paraphenylenediamine antioxidant is in the range of 4 to 10 parts by weight per 100 parts by weight of rubber. Less than 4 parts by weight,
The effect of preventing cracks caused by sunlight irradiation and repeated compressive deformation described above is not sufficiently exhibited.
Further, even if the amount exceeds 10 parts by weight, the effect will not be so great. This sheet 3
By providing this, the amount of paraphenylenediamine anti-aging agent in the cap lead part A, which is usually not affected by sunlight, can be kept to 3 parts by weight or less per 100 parts by weight of rubber, which is economical. . In addition, even in the rubber compounding for the center to lower part of the tire sidewall, that is, the sidewall part B, which is affected by sunlight, the amount of paraphenylenediamine-based anti-aging agent can be kept to 2 to 7 parts by weight, and it has excellent resistance to elongation and deformation. The composition can be made mainly of SBR. The paraphenylenediamine type (hereinafter referred to as p-phenylenediamine type) anti-aging agent used in the present invention is, for example, N,N'-diphenyl-p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylene diamine, N-phenyl-
N'-1,3-dimethylbutyl-p-phenylenediamine, N,N'-bis(1,3-dimethylbutyl)-p-phenylenediamine, N,N'-bis-2-naphthyl-p- It can be arbitrarily selected from phenylene diamines and the like. In addition to the p-phenylenediamine-based sheet 3 of the present invention, other anti-aging agents, such as 2,
2,4-trimethyl-1,2-dihydroquinoline polymer (RD), 6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, etc. can be blended as appropriate. The amount of carbon black to be used is 40 to 70 parts by weight, preferably 45 to 65 parts by weight, per 100 parts by weight of rubber. This requires a carbon content of 40 parts by weight or more to maintain wear resistance, and if the carbon content is 70 parts by weight or more, a large amount of oil must be added to maintain mixing processability, which naturally affects physical properties such as tensile strength. This results in a decrease in ozone resistance. As for the type of carbon used here, those with an iodine adsorption amount of 35 mg/g or more and a DBP oil absorption amount of 70 ml/100 g or more are used alone or in a blend of two or more types, but carbon with an iodine adsorption amount of 80 mg/g or more is used. It is effective for wear resistance to use at least 25% of the total amount of carbon black used. In addition, appropriate amounts of sulfur, vulcanization accelerator, accelerator aid, etc. necessary for the rubber composition are blended, and among these, it is desirable to select the accelerator. Since this sheet contains a very large amount of anti-aging agent, there is a risk that scorch will occur quickly.To prevent this, sulfenamide-based thiazoles are suitable among thiazoles, and sulfenamide-based vulcanization accelerators are used.
If it is blended in the range of 0.5 to 1.5 parts by weight, there will be no scorch problem and optimum physical properties such as modulus can be obtained. Regarding the thickness of the sheet 3, it is economically preferable that the thickness of the sheet 3 be as thin as possible since a large amount of an expensive anti-aging agent is blended as described above. However, if it is made too thin, the anti-aging agent will precipitate on the surface (Ieaching phenomenon) or migrate to the adjacent rubber layer, causing a rapid decrease in concentration and becoming ineffective. In addition, in the present invention, a rubber composition excellent in ordinary wear resistance, cut chip resistance, etc. is used as the captread rubber, and a rubber composition with ordinary flex fatigue resistance and low rolling resistance is used as the sidewall rubber. Any rubber composition of choice may be used and is not particularly limited. The present inventors created samples by changing the gauge ratio of the laminate body of the sheet and the tread rubber so that the total thickness was 10 mm, and after exposing the samples outdoors for 12 months, the amount of anti-aging agent in the sheet part of each sample was determined. conducted an analysis. The test piece was prepared by laminating a rubber compounded in Example 4 and a rubber compounded in Comparative Example 6, which will be described later, and vulcanizing and adhering them. As shown in FIG. 4, the residual rate of the anti-aging agent decreases when the thickness is less than 0.5 mm. Therefore, the thickness of the sheet needs to be 0.5 mm or more, but the upper limit is 5 mm considering economic efficiency. In addition, it is best to arrange the width from near the ground contact edge of the upper part of the shoulder to cover the joint between the tread rubber and the sidewall rubber. The width is preferably 50 to 150 mm for truck and bus tires.
The sheet 3 can be pasted in any way as long as it is placed at the above-mentioned position on the tire, but it is best to stick the sheet 3 on the tire when it is not yet vulcanized. Good. A special adhesive is required after vulcanization, and there is a risk of peeling off under the harsh conditions of use of large tires. Therefore, as long as the rubber is not cured, it may be laminated at any step, but doing so at the time of tire assembly and molding actually reduces work efficiency, and moreover, the rubber to be laminated to each other may deteriorate over time after extrusion. As the temperature decreases and the tackiness decreases, it becomes difficult to exhibit self-adhesive properties as an unvulcanized rubber. On the other hand, if you extrude the rubber 2 for the ground-contacting part and the side wall part and the sheet 3 at the same time and stick them together at the same time, the work efficiency will be good and the sheet rubber 3 will be extruded.
Good adhesion between the rubber 1 and the cap lead portion can be obtained. Next, we will discuss the strains that each part of the tire receives. FIG. 5 shows measurements of the shear strain that the surface of the tire T receives on its grounding point. It can be seen that there is a peak of shear strain from the top of the sidewall portion B of the tire to the edge of the tread, particularly at the position where the sheet of the present invention is attached. Tire size 1000−20, air pressure 6.75Kg/cm 2 , load 2700Kg, π
Measured using a gauge meter. FIG. 6 is a diagram showing the shear strain shown in FIG. 5 broken down into a circumferential component and a cross-sectional component, and into compressive strain and extensional strain. It can be seen that there is a large peak of compressive strain in the cross-sectional direction, especially in the shoulder portion C, and that elongation strain is applied in the circumferential direction in the middle to lower part of the side wall. FIG. 7 is a diagram showing the relationship between the angle (distance) in the circumferential direction from the tire grounding point (assumed to be 0°) and the strain in the tangential direction of the tire tread at each angle. It can be seen that there is an extensional strain in the circumferential direction at the tire contact point (0°), and a compressive strain is applied at points 15 to 20° away from the tire contact point. This figure shows that compressive strain and extensional strain are applied repeatedly during tire rotation. 6 and 7 are measurements taken under the same conditions as in FIG. 5, such as size, air pressure, load, etc. Next, the present invention will be explained in more detail with reference to Examples. Experimental example 1 In Table 1, NR, BR, and SBR are combined, zinc oxide, stearic acid, carbon black, anti-aging agent, wax, and extender oil are kneaded in a small banbury, and sulfur and vulcanization accelerator are kneaded in a roll. 148
Vulcanization was performed by heating at ℃ for 30 minutes. Among them, characteristics relevant to the present invention were shown. From this result, NR and
When the BR combination is up to 70:30 or 55:45, each property can be satisfied, but when the BR is combined in the majority, such as 40:60, the compression fatigue resistance is good, but the tear strength and cut resistance are significantly reduced. , undesirable. In order to impart cut resistance, it is preferable to mix 10 to 30% by weight of SBR out of 100% rubber. When SBR exceeds 30%, compression fatigue resistance decreases significantly. From the above, when NR is blended with BR
55% by weight or more is optimal, and BR is around 40%. In addition, in the case of a three-way blend with SBR, 10 to 20 of the NR
It was found that changing the weight % range to SBR satisfies all the characteristics and is optimal. Note that a falling cut tester (also referred to as a guillotine cut) was used for the cut resistance test. This machine evaluates cut resistance by dropping a blade with a constant load onto a vulcanized rubber sample from a height of 15 to 25 cm and measuring the penetration depth of the blade. Experimental Example 2 Table 2 shows the types of carbon black and anti-aging (S
-13) The results of the study are shown below. As for the grade of carbon, N770 is not satisfactory due to the need to impart wear resistance to the side wall portion, and the above range is limited.
In addition, the p-phenylenediamine anti-aging agent S-
If the amount of 13 is less than 4 parts by weight per 100 parts by weight of rubber, ozone resistance will decrease. The same table shows tread rubber (Comparative Example 6) and general side wall rubber (Comparative Example 7) as comparative examples. As is clear from this, rubber 1 for the tread portion (for the cap lead portion) and rubber 2 for the side wall portion (for the sidewall portion) have poor compression fatigue resistance.
Furthermore, it can be seen that the ozone resistance of the tread portion is significantly inferior. Also, the modulus of the compound is
A suitable modulus of 80 to 120 Kg/cm 2 at 300% deformation is 80 to 90 Kg/cm in terms of bending fatigue resistance, since the upper part of the side wall is constructed by pasting sheet 3 on top of rubber 1 for the tread. A range of 2 is preferred.
【表】【table】
【表】【table】
【表】【table】
【表】
実験例 ３
第１図の従来のキヤツプ・オーバー・サイド構
造、第２図の従来のサイド・オーバー・キヤツプ
構造、第３図ａ，ｂの本発明構造のタイヤにつ
き、実車走行試験、ドラム試験（オゾン照射）な
らびに静的オゾン試験を行なつた。結果を第３
表、第４表に示す。[Table] Experimental Example 3 Actual vehicle running tests were carried out on tires with the conventional cap-over-side structure shown in Fig. 1, the conventional side-over-cap structure shown in Fig. 2, and the structure of the present invention shown in Figs. 3 a and b. A drum test (ozone irradiation) and a static ozone test were conducted. 3rd result
Table 4 shows the results.
【表】【table】
【表】
以上のように本発明構造のタイヤと従来品構造
のタイヤについて実車テスト、オゾン照射テスト
を行つたところ、12ケ月経過の実車試験で該側壁
部のクラツク発生及び屈曲疲労によるしわ又はク
ラツクの発生程度は本発明のものが最も良いこと
がわかつた。[Table] As mentioned above, actual vehicle tests and ozone irradiation tests were conducted on tires with the structure of the present invention and tires with conventional product structures, and after 12 months of actual vehicle tests, cracks occurred in the side wall portion and wrinkles or cracks due to bending fatigue were observed. It was found that the method of the present invention has the best degree of occurrence of .
【表】
本発明は上述したように、耐屈曲疲労性、耐候
性及び耐摩耗性に優れたゴム組成物からなる厚さ
0.5〜５mmのゴムシートを、踏面接地端部ａから
ビード端部ｂ方向に約１〜10mm下方の位置から幅
50〜150mmにわたつて、少なくとも踏面ゴムとサ
イドウオールゴムとの接合部を覆うと共に、タイ
ヤの表面に沿つてタイヤ周方向に配置したから、
従来キヤツプトレツド部のゴム及びサイドウオー
ル部のゴムに兼備させていたシヨルダー部附近の
機能を独立せしめることができて、より効果的に
走行時に繰り返し圧縮変形を最も厳しく受け、し
かも踏面ゴムとサイドウオールゴムとの接合部を
有するシヨルダー部付近の耐屈曲疲労性、耐候性
及び耐摩耗性を向上できる一方、キヤツプトレツ
ド部のゴム及びサイドウオール部のゴムの各組成
を、それぞれの必要機能に合わせて最適化し、併
せてタイヤ構成材料コストの低減を図ることがで
きる。
従つて本発明は、トラツク、バス用空気入りタ
イヤの耐動的疲労性や耐候性、耐摩耗性を向上す
ることができると共にその生産コストをも低減す
ることができる。[Table] As mentioned above, the present invention provides a rubber composition made of a rubber composition with excellent bending fatigue resistance, weather resistance, and abrasion resistance.
Apply a 0.5 to 5 mm rubber sheet to the width from a position approximately 1 to 10 mm downward from the tread end a to the bead end b.
Because it covers at least the joint between the tread rubber and the sidewall rubber over a length of 50 to 150 mm, and is placed along the tire surface in the tire circumferential direction,
Conventionally, the functions near the shoulder part, which were combined with the rubber of the cap lead part and the rubber of the sidewall part, can be made independent, and the function can be more effectively subjected to repeated compressive deformation during driving, while the tread rubber and sidewall rubber are It is possible to improve the bending fatigue resistance, weather resistance, and abrasion resistance near the shoulder part where it joins with the cap, while optimizing the composition of the rubber in the cap lead part and the rubber in the sidewall part to suit each required function. At the same time, it is possible to reduce the cost of tire constituent materials. Therefore, the present invention can improve the dynamic fatigue resistance, weather resistance, and abrasion resistance of pneumatic tires for trucks and buses, and can also reduce the production cost thereof.
第１図及び第２図はそれぞれ従来の空気入りタ
イヤのラジアル方向断面説明図、第３図ａ，ｂは
それぞれ本発明の実施例からなる空気入りタイヤ
のラジアル方向断面説明図、第４図は前記シート
の肉厚と老化防止剤残存率との関係を示す屋外曝
露試験結果を示す図、第５図は走行時においてタ
イヤの接地両端部からビード部に至る各部分が受
ける主せん断歪の測定結果を示す図、第６図は走
行時においてタイヤの接地面端部からビード部に
至る各部分が受ける主歪の測定結果を示す図、第
７図は走行時においてタイヤが接地点から周方向
に向けて円周上においてタイヤ踏面部がその接線
方向に受ける歪を示す図である。
１……キヤツプトレツド部のゴム、２……サイ
ドウオール部のゴム、３……シート、Ａ……キヤ
ツプトレツド部、Ｂ……サイドウオール部、Ｃ…
…シヨルダー部。
1 and 2 are explanatory radial cross-sectional views of a conventional pneumatic tire, FIGS. 3 a and b are radial cross-sectional views of a pneumatic tire according to an embodiment of the present invention, and FIG. A diagram showing the results of an outdoor exposure test showing the relationship between the thickness of the sheet and the residual rate of anti-aging agent. Figure 5 shows the measurement of the main shear strain that is applied to each part of the tire from both ends of the tire in contact with the ground to the bead part during running. Figure 6 is a diagram showing the results. Figure 6 is a diagram showing the measurement results of the principal strain that each part of the tire receives from the edge of the tire's contact surface to the bead during driving. Figure 7 is a diagram showing the measurement results of the principal strain that the tire receives in the circumferential direction from the ground contact point while driving. It is a figure which shows the strain which the tire tread part receives in the tangential direction on the circumference toward . 1... Rubber of the cap lead part, 2... Rubber of the side wall part, 3... Seat, A... Cap lead part, B... Side wall part, C...
...shoulder section.
Claims (1)
リブタジエンゴムとを含有するゴム100重量部に
対し、パラフエニレンジアミン系老化防止剤４〜
10重量部及びカーボンブラツク40〜70重量部を配
合したゴム組成物からなる厚さ0.5〜５mmのゴム
シートを、踏面接地端部ａからビード端部ｂ方向
に約１〜10mm下方の位置から幅50〜150mmにわた
つて、少なくとも踏面ゴムとサイドウオールゴム
との接合部を覆うと共に、タイヤの表面に沿つて
タイヤ周方向に配置したトラツク・バス用空気入
りタイヤ。 ２ 40〜70重量部の天然ゴムと30〜60重量部のポ
リブタジエンゴムと30重量部以下のスチレン・ブ
タジエン共重合ゴムとを含有するゴム100重量部
に対し、パラフエニレンジアミン系老化防止剤４
〜10重量部及びカーボンブラツク40〜70重量部を
配合したゴム組成物からなる厚さ0.5〜５mmのゴ
ムシートを、踏面接地端部ａからビード端部ｂ方
向に約１〜10mm下方の位置から幅50〜150mmにわ
たつて、少なくとも踏面ゴムとサイドウオールゴ
ムとの接合部を覆うと共に、タイヤの表面に沿つ
てタイヤ周方向に配置したトラツク・バス用空気
入りタイヤ。[Scope of Claims] 1. 4 to 4 parts by weight of a paraphenylenediamine anti-aging agent to 100 parts by weight of rubber containing 40 to 70 parts by weight of natural rubber and 30 to 60 parts by weight of polybutadiene rubber.
A rubber sheet with a thickness of 0.5 to 5 mm made of a rubber composition containing 10 parts by weight and 40 to 70 parts by weight of carbon black is applied from a position approximately 1 to 10 mm below the tread end a to the bead end b. A pneumatic tire for trucks and buses that has a width of 50 to 150 mm, covers at least the joint between tread rubber and sidewall rubber, and is arranged circumferentially along the tire surface. 2 For 100 parts by weight of rubber containing 40 to 70 parts by weight of natural rubber, 30 to 60 parts by weight of polybutadiene rubber, and 30 parts by weight or less of styrene-butadiene copolymer rubber, paraphenylenediamine-based anti-aging agent 4
A rubber sheet with a thickness of 0.5 to 5 mm made of a rubber composition containing ~10 parts by weight and 40 to 70 parts by weight of carbon black is placed at a position approximately 1 to 10 mm downward from the tread end a to the bead end b. A pneumatic tire for trucks and buses that extends from 50 to 150 mm in width, covers at least the joint between tread rubber and sidewall rubber, and is arranged circumferentially along the tire surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56124751A JPS5826607A (en) | 1981-08-11 | 1981-08-11 | Pneumatic tire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56124751A JPS5826607A (en) | 1981-08-11 | 1981-08-11 | Pneumatic tire |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5826607A JPS5826607A (en) | 1983-02-17 |
| JPH0319802B2 true JPH0319802B2 (en) | 1991-03-18 |
Family
ID=14893208
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56124751A Granted JPS5826607A (en) | 1981-08-11 | 1981-08-11 | Pneumatic tire |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5826607A (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59216708A (en) * | 1983-05-23 | 1984-12-06 | Bridgestone Corp | Pneumatic tire |
| JPS6395905U (en) * | 1986-08-08 | 1988-06-21 | ||
| JP2634860B2 (en) * | 1987-06-30 | 1997-07-30 | 株式会社ブリヂストン | Pneumatic tire |
| JP2702862B2 (en) * | 1992-12-28 | 1998-01-26 | 住友ゴム工業株式会社 | Heavy duty tire |
| JP4037513B2 (en) * | 1998-04-09 | 2008-01-23 | 住友ゴム工業株式会社 | Rubber composition for tire |
| JP2006151327A (en) * | 2004-12-01 | 2006-06-15 | Sumitomo Rubber Ind Ltd | Pneumatic tire and its manufacturing method |
| JP2007332325A (en) * | 2006-06-19 | 2007-12-27 | Toyo Tire & Rubber Co Ltd | Rubber composition and air spring using it |
| JP5464811B2 (en) * | 2008-03-14 | 2014-04-09 | 株式会社ブリヂストン | tire |
| JP5345876B2 (en) * | 2009-03-09 | 2013-11-20 | 株式会社ブリヂストン | Pneumatic tire |
| JP6136131B2 (en) * | 2012-07-03 | 2017-05-31 | 横浜ゴム株式会社 | Rehabilitation tire |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS521761A (en) * | 1975-06-24 | 1977-01-07 | Nittetsu Mining Co Ltd | Device of joining and supporting centrifugal separatohousing of a cent rifugal separator |
| JPS5396102A (en) * | 1977-02-03 | 1978-08-23 | Toyo Tire & Rubber Co Ltd | Off-the-road tire |
| JPS56160203A (en) * | 1980-05-10 | 1981-12-09 | Sumitomo Rubber Ind Ltd | Radial tire for automobile |
| JPS581735A (en) * | 1981-06-27 | 1983-01-07 | Toyo Tire & Rubber Co Ltd | Composition for side wall of tire |
-
1981
- 1981-08-11 JP JP56124751A patent/JPS5826607A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS521761A (en) * | 1975-06-24 | 1977-01-07 | Nittetsu Mining Co Ltd | Device of joining and supporting centrifugal separatohousing of a cent rifugal separator |
| JPS5396102A (en) * | 1977-02-03 | 1978-08-23 | Toyo Tire & Rubber Co Ltd | Off-the-road tire |
| JPS56160203A (en) * | 1980-05-10 | 1981-12-09 | Sumitomo Rubber Ind Ltd | Radial tire for automobile |
| JPS581735A (en) * | 1981-06-27 | 1983-01-07 | Toyo Tire & Rubber Co Ltd | Composition for side wall of tire |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5826607A (en) | 1983-02-17 |
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