JP4262972B2 - Pneumatic tire manufacturing method - Google Patents
Pneumatic tire manufacturing method Download PDFInfo
- Publication number
- JP4262972B2 JP4262972B2 JP2002360745A JP2002360745A JP4262972B2 JP 4262972 B2 JP4262972 B2 JP 4262972B2 JP 2002360745 A JP2002360745 A JP 2002360745A JP 2002360745 A JP2002360745 A JP 2002360745A JP 4262972 B2 JP4262972 B2 JP 4262972B2
- Authority
- JP
- Japan
- Prior art keywords
- tread
- tire
- sheet
- belt
- vulcanization
- 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
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 14
- 229920001971 elastomer Polymers 0.000 claims description 26
- 239000005060 rubber Substances 0.000 claims description 26
- 238000004073 vulcanization Methods 0.000 claims description 25
- 239000000203 mixture Substances 0.000 claims description 16
- 239000000945 filler Substances 0.000 claims description 12
- 229920003244 diene elastomer Polymers 0.000 claims description 10
- 238000002156 mixing Methods 0.000 claims description 3
- 239000011324 bead Substances 0.000 description 6
- 239000006229 carbon black Substances 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 5
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000011156 evaluation Methods 0.000 description 4
- 238000013329 compounding Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 235000012239 silicon dioxide Nutrition 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 244000043261 Hevea brasiliensis Species 0.000 description 2
- 230000003712 anti-aging effect Effects 0.000 description 2
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 description 2
- 239000004927 clay Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229920003052 natural elastomer Polymers 0.000 description 2
- 229920001194 natural rubber Polymers 0.000 description 2
- 239000004014 plasticizer Substances 0.000 description 2
- 229920002857 polybutadiene Polymers 0.000 description 2
- 229920001195 polyisoprene Polymers 0.000 description 2
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 2
- 229920003048 styrene butadiene rubber Polymers 0.000 description 2
- 239000000454 talc Substances 0.000 description 2
- 229910052623 talc Inorganic materials 0.000 description 2
- 239000005995 Aluminium silicate Substances 0.000 description 1
- 229920002943 EPDM rubber Polymers 0.000 description 1
- 239000005062 Polybutadiene Substances 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- YKTSYUJCYHOUJP-UHFFFAOYSA-N [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] Chemical compound [O--].[Al+3].[Al+3].[O-][Si]([O-])([O-])[O-] YKTSYUJCYHOUJP-UHFFFAOYSA-N 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 239000012752 auxiliary agent Substances 0.000 description 1
- 229920005549 butyl rubber Polymers 0.000 description 1
- 239000000378 calcium silicate Substances 0.000 description 1
- 229910052918 calcium silicate Inorganic materials 0.000 description 1
- OYACROKNLOSFPA-UHFFFAOYSA-N calcium;dioxido(oxo)silane Chemical compound [Ca+2].[O-][Si]([O-])=O OYACROKNLOSFPA-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000010445 mica Substances 0.000 description 1
- 229910052618 mica group Inorganic materials 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 239000012744 reinforcing agent Substances 0.000 description 1
- 238000010058 rubber compounding Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 238000009864 tensile test Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
Images
Landscapes
- Tires In General (AREA)
- Tyre Moulding (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、二つ割りタイプの金型を用いて加硫成形する空気入りタイヤの製造方法において、加硫後にタイヤが金型から離型する際のトレッド欠けを軽減する製造方法に関する。
【０００２】
【従来の技術】
従来、二つ割りタイプの金型を用いて空気入りタイヤの製造する場合、加硫後のタイヤの離型性に起因しトレッド欠けを生ずるという問題があった。タイヤを加硫した後、タイヤを加硫金型から取出す際、上金型と下金型の二つの加硫金型は上下に相互に離れるように移動する。これはタイヤの幅方向に金型が移動することを意味する。この場合、トレッド部のリブパターンあるいはブロックパターンの凸部は、タイヤ幅方向に変形歪が生じ、凸部は部分的に欠けが生ずることになる。特に深溝タイプのトレッドパターンの場合、変形歪が著しくトレッド欠けが激しくなる。
【０００３】
このようなトレッド欠けの問題を解消するため、加硫金型を円周方向に複数のセグメントに分割し、加硫後にはこれらセグメントがタイヤのラジアル方向に移動するマルチセグメントタイプの金型が使用されている。この金型はトレッド溝方向に沿って移動する為、トレッド部の凸部に変形歪を生ずることがなくトレッド欠けの問題を生じない。しかしながら、この種の金型は二つ割りタイプの金型に較べ、金型の製作費用が高く汎用性が少ない問題がある。
【０００４】
そこで二つ割りタイプの金型で加硫成形する場合において、トレッドゴムに高温で伸び率の高いゴムを用いたり、トレッド溝の形状を工夫したりしてタイヤ幅方向の変形歪に対して損傷が発生しない技術が検討されていた。また、加硫後の１００℃破断時伸びが３００％〜７００％の未加硫ゴム組成物からなる薄膜をグリーンタイヤのトレッド面に被覆し、該グレーンタイヤを二つ割りタイプの金型で加硫成形する空気入りタイヤの製造方法が提案されている（特許文献１参照）。しかしながらこの技術はタイヤの初期摩耗性および操縦安定性が必ずしも満足できるものではない。
【０００５】
【特許文献１】
特開平１０−２７２７０６号公報
【０００６】
【発明が解決しようとする課題】
本発明は上記問題を解決するもので、二つ割りタイプの金型を用いて加硫成形する空気入りタイヤの製造方法において、加硫後にタイヤが金型から離型する際のトレッド欠けを軽減し、かつ操縦安定性を改善した空気入りタイヤの製造方法を提案する。
【０００７】
【課題を解決するための手段】
本発明は二つ割りタイプの金型を用いて加硫成形する空気入りタイヤの製造方法において、ジエン系ゴム１００質量部に対して、充填剤の配合量が６５質量部未満であるトレッドゴム組成物の表面を、ジエン系ゴム１００質量部に対して充填剤が６５質量部以上のゴム組成物で、厚さが０．５〜４．０ｍｍで加硫後の破断強度（ＴB）が２０ＭＰａ以上で１００ＭＰａ以下の未加硫の帯状シートで被覆し、加硫成形したことを特徴とする空気入りタイヤの製造方法である。
【０００８】
前記未加硫帯状シートの幅はタイヤトレッド幅の６０％以下であり、加硫後の帯状シートの破断強度（ＴB）が２２ＭＰａ以上で５０ＭＰａ以下であることが好ましい。
【０００９】
【発明の実施の形態】
＜タイヤ構造＞
本発明の空気入りタイヤは、トラック／バス用タイヤ、ライトトラック用タイヤ、乗用車用タイヤ等のすべてのカテゴリーに適用できる。本発明の乗用車用空気入りタイヤを、図１に示す断面図の右半分、そのトレッド部の部分拡大図を示す図２にしたがって説明する。図１及び図２において空気入りタイヤ１は、左右一対のビードコア４の間に装架され両端が前記ビードコア４とその外側のビードエーペックス５を包むようにタイヤ内側から外側にかけて折り返されて係止されたカーカス２を備えている。そしてタイヤクラウン部外側には二層のプライよりなる環状のベルト層３がタイヤ円周方向に配置されている。そしてトレッド部６にはトレッド溝７が形成されており、ほぼ一定の厚さ（Ｔ）の帯状シート８がトレッドの外側輪郭線に沿って配置されている。
【００１０】
＜帯状シート＞
ここで帯状シートの加硫後の厚さ（Ｔ）は０．５ｍｍ以上で４．０ｍｍ以下である。帯状シートの厚さ（Ｔ）が０．５ｍｍ未満の場合、トレッド欠けの防止の効果は少なく、一方、４．０ｍｍを超えると操縦安定性あるいはグリップ性などの基本特性が犠牲になる可能性がある。好ましくは帯状シートの厚さ（Ｔ）は１．０〜３．０ｍｍの範囲である。
【００１１】
次に帯状シートは加硫後の破断強度（ＴB）が２０ＭＰａ以上で１００ＭＰａ以下である。前記破断強度（ＴB）が２０ＭＰａ未満の場合、タイヤを加硫後に金型から取出す際に、トレッド溝近傍での変形量が大きくなりトレッド欠けが有効に防止できない。一方、１００ＭＰａを超えるとゴムの剛性が高くなり、トレッド溝近傍の変形量が小さくタイヤを金型から取出す際の変形に追随できずトレッド欠けが効果的に防止できない。前記破断強度（ＴB）は、好ましくは２２〜５０ＭＰａの範囲である。
【００１２】
帯状シートは、ジエン系ゴム１００質量部に対して充填剤が６５質量部以上のゴム組成物で構成する。ここで充填剤として、カーボンブラック、重質炭酸カルシウム、軽微法炭酸カルシウム、特殊タンカル、塩基性炭酸マグネシウム、石英粉末、合成無水珪酸、合成含水珪酸、合成珪酸カルシウム、合成珪酸アルミニウム、カオリンクレー、焼成クレー、タルク、微分タルク、マイカ、水酸化アルミニウム、水酸化マグネシウム、硫酸バリウムなどを使用できる。ここで充填剤を６５質量部以上配合することで、帯状シートの加硫後の破断強度（ＴB）が前述の範囲のものが得られる。充填剤の配合量は、好ましくは７５〜１００質量部の範囲である。
【００１３】
次に前記ジエン系ゴムは、天然ゴム、ポリブタジエンゴム、スチレン−ブタジエンゴム、ポリイソプレンゴム、ブチルゴム、ＥＰＤＭなどが使用される。なお上記ジエン系ゴム成分中、２０質量％以下の範囲でジエン系ゴム以外のゴム成分を混合することができる。
【００１４】
また、ゴム組成物には通常トレッドゴムに配合される一般的な配合剤、例えば、補強剤、可塑剤、軟化剤、老化防止剤、加硫促進剤、硫黄、加硫助剤などを適宜配合できる。
【００１５】
更に前記未加硫帯状シートの幅（Ｌ）はタイヤトレッド幅（ＴＷ）の６０％以下が好ましい。ここでトレッド幅（ＴＷ）はショルダー部の輪郭線の延長線Ｒ2と、トレッド部の輪郭線の延長線Ｒ1の交点を仮想トレッド端Ｅとして、仮想トレッド端Ｅの間の距離ＴＷとして定義される。そして（Ｌ／ＴＷ×１００）は６０％以下、特に好ましくは２０〜６０％の範囲である。
【００１６】
帯状シートはトレッド部の中央部近傍に配置されることが重要であり、タイヤを金型から取出す際、トレッド部のこの領域での離型性が悪く、しかも変形歪が激しくトレッド欠けを生じやすいからである。一方、トレッド端部近傍ではタイヤの離型性が良く、また変形歪も比較的少ないので帯状シートの配置は必須ではない。乗用車タイヤでは、帯状シートの幅（Ｌ）は通常、５０〜１２０ｍｍの範囲のものが使用される。
【００１７】
＜トレッドゴム＞
本発明の空気入りタイヤのトレッドゴム組成物は、ジエン系ゴム１００質量部に対して、充填剤が６５質量部未満配合される。ウエットグリップ性及び乗り心地性などを指向した空気入りタイヤのトレッド部のゴム配合は、一般に軟らくする必要があり充填剤の配合量は少ない。この場合、加硫後のタイヤの離型性が悪くトレッド欠けの問題が生じる。本発明は充填剤を６５質量部未満、好ましくは５０〜６３質量部としてウエットグリップ性及び乗り心地性などに優れた空気入りタイヤに好適に適用し得る。なおトレッドゴムの破断強度（ＴB）は、１５〜２５ＭＰａの範囲のものが採用される。
【００１８】
トレッドゴム組成物は、通常のゴム配合が採用できる。即ち、天然ゴム、ブタジエンゴム、スチレン−ブタジエンゴム、ポリイソプレンゴムなどのジエン系ゴムに、カーボンブラック、シリカなどの充填剤のほか、可塑剤、軟化剤、老化防止剤、加硫剤および加硫助剤などがトレッドゴムの要求特性に応じて所定量配合される。
【００１９】
＜空気入りタイヤの製造方法＞
本発明は従来の方法で、ビードコア、カーカス、ベルト層及びトレッドゴムをドラム上で成形し、トロイド状のグリーンタイヤを製作する。そのトレッド部の中央部付近に未加硫の帯状シートをグリーンタイヤの円周方向に配置し、加硫金型で、通常の加硫をする。帯状シートはタイヤ加硫後に前述の破断強度を有するためトレッド部の凸部の変形歪が生じても欠けの問題を生じない。なお未加硫の帯状シートはグリーンタイヤをトロイド状にする前の円筒形状において配置することもでき、また帯状シートを未加硫状態から部分加硫状態にして配置することもできる。
【００２０】
【実施例】
実施例１、２及び比較例１
表１の配合Ｂに示すゴム組成物をトレッドゴムに用いて、タイヤサイズ１７５Ｒ１４ＰＲで図１に示す構造の空気入りタイヤを製作した。
【００２１】
表１の配合Ａでカーボンブラックを変量してゴム組成物を調整して、シート幅が１００ｍｍ（Ｌ／ＴＷ×１００＝６０％）で厚さ２ｍｍの未加硫ゴムシートを製作し、トロイド状グリ−ンタイヤのトレッド部の円周方向に配置し、加硫金型で１７０℃で８分間加硫した。帯状シートの破断強度、タイヤのデモールド性の評価は以下の方法で行なった。
【００２２】
（１） 破断強度（ＴB）の測定
ＪＩＳ−Ｋ６２５１に準じて３号ダンベル試験片を作成し、引っ張り試験を行なって破断時の強度を測定した。
【００２３】
（２）デモールド性
実施例ごとに１０本のタイヤを製作し、加硫金型からタイヤを取出す際のトレッド欠けの状態を目視で評価した。評価基準は次のとおりである。
【００２４】
○ ：トレッド欠けは発生しなかった。
△ ：トレッド欠けは１〜４ヶ所認められた。
【００２５】
× ：トレッド欠けは５ヶ所以上認められた。
表２にカーボンブラック配合量、破断強度とデモールド性の評価結果を示す。表２において帯状シートのカーボンブラックの配合量が、６５質量部（実施例１）、７５重量部（実施例２）は、５５重量部（比較例１）よりもデモールド性に優れていることが判る。
【００２６】
【表１】
【表２】
実施例３〜５及び比較例２
帯状シートの厚さとデモールド性の関係を表３に示す。帯状シートの厚さ以外はすべて実施例２と同じ仕様のタイヤを用いた。
【００２９】
【表３】
表３において、帯状シートの厚さが、０．５ｍｍ（実施例３）、２ｍｍ（実施例４）、３ｍｍ（実施例５）は、０．３ｍｍ（比較例２）よりもデモールド性に優れている。
【００３１】
実施例６〜１１
帯状シートの幅（Ｌ）と操縦安定性の関係を表４に示す。帯状シートは二種類の厚さのものについて示している。帯状シートの幅以外はすべて実施例２と同じ仕様のタイヤを用いた。
【００３２】
ここで操縦安定性は、実施例の各タイヤを実車走行し、ハンドル応答性を評価した。実施例６を６点として相対評価をした。数値が大きいほうが操縦安定性に優れている。
【００３３】
【表４】
表４において、Ｌ／ＴＷ×１００が６０％以下の場合、特に操縦安定性に優れていることがわかる。
【００３５】
【発明の効果】
上述の如く本発明は、トレッド部の表面に二つ割りタイプの金型を用いて加硫成形する空気入りタイヤの製造方法において、充填剤の配合量が６５質量部未満であるトレッドゴム組成物の表面を、６５質量部以上のゴム組成物で、厚さが０．５以上で４．０ｍｍ以下で、加硫後の破断強度（ＴB）が２０ＭＰａ以上で１００ＭＰａ以下の未加硫の帯状シートで被覆したため、トレッド欠けを効果的に軽減することができる。
【図面の簡単な説明】
【図１】 本発明に基づく空気入りタイヤの右半分の断面図である。
【図２】 図１のトレッド部の部分拡大図である。
【符号の説明】
１ 空気入りタイヤ、２ カーカス、３ ベルト層、４ ビードコア、５ ビードエーペックス、６ トレッド部、７ トレッド溝、８ 帯状シート。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method of a pneumatic tire that is vulcanized and molded using a split mold, and the tread chipping is reduced when the tire is released from the mold after vulcanization.
[0002]
[Prior art]
Conventionally, when a pneumatic tire is manufactured using a split mold, there is a problem that tread chipping occurs due to the release property of the tire after vulcanization. After the tire is vulcanized, when the tire is taken out from the vulcanization mold, the two vulcanization molds, the upper mold and the lower mold, move up and down away from each other. This means that the mold moves in the width direction of the tire. In this case, the rib pattern of the tread part or the convex part of the block pattern is deformed in the tire width direction, and the convex part is partially chipped. In particular, in the case of a deep groove type tread pattern, deformation distortion is remarkable and tread chipping becomes severe.
[0003]
In order to eliminate the problem of tread chipping, the vulcanization mold is divided into multiple segments in the circumferential direction, and after vulcanization, a multi-segment type mold that moves in the radial direction of the tire is used. Has been. Since this mold moves along the tread groove direction, deformation distortion does not occur in the convex portion of the tread portion, and the problem of tread chipping does not occur. However, this type of mold has a problem in that the mold production cost is high and the versatility is low compared to the split type mold.
[0004]
Therefore, when vulcanization molding is performed with a split mold, damage to the deformation strain in the tire width direction may occur due to the use of a rubber with high elongation at high temperatures or a tread groove shape. The technology which does not do was examined. Further, a thin film made of an unvulcanized rubber composition having an elongation at break at 100 ° C. of 300% to 700% after vulcanization is coated on a tread surface of a green tire, and the grain tire is vulcanized with a split mold. A method for manufacturing a pneumatic tire is proposed (see Patent Document 1). However, this technique does not always satisfy the initial wearability and steering stability of the tire.
[0005]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-272706
[Problems to be solved by the invention]
The present invention solves the above problems, and in the method for producing a pneumatic tire vulcanized using a split mold, the tread chipping when the tire is released from the mold after vulcanization is reduced, A method of manufacturing a pneumatic tire with improved handling stability is proposed.
[0007]
[Means for Solving the Problems]
The present invention relates to a method for producing a pneumatic tire that is vulcanized and molded using a split mold, and a tread rubber composition having a filler content of less than 65 parts by mass with respect to 100 parts by mass of a diene rubber. The surface is a rubber composition having a filler of 65 parts by mass or more with respect to 100 parts by mass of the diene rubber, the thickness is 0.5 to 4.0 mm, and the rupture strength (T B ) after vulcanization is 20 MPa or more. It is a method for producing a pneumatic tire, characterized in that it is coated with an unvulcanized belt-like sheet of 100 MPa or less and vulcanized.
[0008]
The unvulcanized belt-like sheet has a width of 60% or less of the tire tread width, and the rupture strength (T B ) of the vulcanized belt-like sheet is preferably 22 MPa or more and 50 MPa or less.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
<Tire structure>
The pneumatic tire of the present invention can be applied to all categories such as truck / bus tires, light truck tires, and passenger car tires. The pneumatic tire for passenger cars according to the present invention will be described with reference to FIG. 2 showing a partially enlarged view of the right half of the cross-sectional view shown in FIG. 1 and 2, the
[0010]
<Strip sheet>
Here, the thickness (T) after vulcanization of the belt-like sheet is 0.5 mm or more and 4.0 mm or less. When the thickness (T) of the belt-like sheet is less than 0.5 mm, the effect of preventing the tread chipping is small. On the other hand, when it exceeds 4.0 mm, basic characteristics such as steering stability or grip performance may be sacrificed. is there. Preferably, the thickness (T) of the belt-like sheet is in the range of 1.0 to 3.0 mm.
[0011]
Next, the belt-like sheet has a breaking strength (T B ) after vulcanization of 20 MPa to 100 MPa. When the breaking strength (T B ) is less than 20 MPa, when the tire is taken out from the mold after vulcanization, the amount of deformation in the vicinity of the tread groove becomes large and tread chipping cannot be effectively prevented. On the other hand, when the pressure exceeds 100 MPa, the rigidity of the rubber becomes high, the deformation amount in the vicinity of the tread groove is small, and it is impossible to follow the deformation when the tire is taken out from the mold, so that tread chipping cannot be effectively prevented. The breaking strength (T B ) is preferably in the range of 22 to 50 MPa.
[0012]
The belt-like sheet is composed of a rubber composition having a filler of 65 parts by mass or more with respect to 100 parts by mass of the diene rubber. Here, carbon black, heavy calcium carbonate, light calcium carbonate, special tancal, basic magnesium carbonate, quartz powder, synthetic anhydrous silicic acid, synthetic hydrous silicic acid, synthetic calcium silicate, synthetic aluminum silicate, kaolin clay, firing Clay, talc, differential talc, mica, aluminum hydroxide, magnesium hydroxide, barium sulfate, etc. can be used. Here, when the filler is blended in an amount of 65 parts by mass or more, the rupture strength (T B ) after vulcanization of the belt-like sheet is in the above-mentioned range. The blending amount of the filler is preferably in the range of 75 to 100 parts by mass.
[0013]
Next, natural rubber, polybutadiene rubber, styrene-butadiene rubber, polyisoprene rubber, butyl rubber, EPDM, or the like is used as the diene rubber. In the diene rubber component, rubber components other than the diene rubber can be mixed within a range of 20% by mass or less.
[0014]
In addition, general compounding agents that are usually compounded into tread rubber, such as reinforcing agents, plasticizers, softeners, anti-aging agents, vulcanization accelerators, sulfur, vulcanization aids, etc., are appropriately blended in the rubber composition. it can.
[0015]
Furthermore, the width (L) of the unvulcanized belt-like sheet is preferably 60% or less of the tire tread width (TW). Here, the tread width (TW) is defined as the distance TW between the virtual tread ends E, where the intersection of the contour line extension R 2 of the shoulder portion and the extension line R 1 of the contour line of the tread portion is the virtual tread end E. Is done. And (L / TWx100) is 60% or less, Most preferably, it is the range of 20-60%.
[0016]
It is important that the belt-like sheet is arranged near the center of the tread portion. When the tire is taken out from the mold, the releasability in this region of the tread portion is poor, and the deformation strain is so strong that the tread chip is likely to occur. Because. On the other hand, in the vicinity of the tread end portion, the release property of the tire is good and the deformation distortion is relatively small, so the arrangement of the belt-like sheet is not essential. In passenger car tires, the width (L) of the belt-like sheet is usually in the range of 50 to 120 mm.
[0017]
<Tread rubber>
In the tread rubber composition of the pneumatic tire of the present invention, the filler is blended in an amount of less than 65 parts by mass with respect to 100 parts by mass of the diene rubber. In general, the rubber compounding of the tread portion of a pneumatic tire oriented for wet grip and riding comfort needs to be softened and the compounding amount of the filler is small. In this case, the releasability of the tire after vulcanization is poor and the problem of tread chipping occurs. The present invention can be suitably applied to a pneumatic tire excellent in wet grip properties and riding comfort, etc. with a filler of less than 65 parts by mass, preferably 50 to 63 parts by mass. The tread rubber has a breaking strength (T B ) in the range of 15 to 25 MPa.
[0018]
As the tread rubber composition, a normal rubber composition can be adopted. In other words, natural rubber, butadiene rubber, styrene-butadiene rubber, polyisoprene rubber and other diene rubbers, in addition to fillers such as carbon black and silica, plasticizers, softeners, anti-aging agents, vulcanizing agents and vulcanizing agents. A predetermined amount of an auxiliary agent or the like is blended according to the required characteristics of the tread rubber.
[0019]
<Pneumatic tire manufacturing method>
The present invention is a conventional method in which a bead core, a carcass, a belt layer and a tread rubber are formed on a drum to produce a toroidal green tire. An unvulcanized belt-like sheet is disposed in the circumferential direction of the green tire near the center of the tread portion, and normal vulcanization is performed with a vulcanization mold. Since the belt-like sheet has the above-described breaking strength after vulcanization of the tire, the problem of chipping does not occur even when the deformation distortion of the convex portion of the tread portion occurs. The unvulcanized belt-like sheet can be arranged in a cylindrical shape before the green tire is made toroidal, or the belt-like sheet can be arranged from an unvulcanized state to a partially vulcanized state.
[0020]
【Example】
Examples 1 and 2 and Comparative Example 1
A pneumatic tire having a tire size of 175R14PR and a structure shown in FIG. 1 was manufactured using the rubber composition shown in Formulation B of Table 1 as a tread rubber.
[0021]
A rubber composition was prepared by varying the carbon black in the composition A in Table 1 to produce an unvulcanized rubber sheet having a sheet width of 100 mm (L / TW × 100 = 60%) and a thickness of 2 mm, and a toroid shape. It was arranged in the circumferential direction of the tread portion of the green tire and vulcanized with a vulcanization mold at 170 ° C. for 8 minutes. Evaluation of the breaking strength of the belt-like sheet and the demolding property of the tire was performed by the following methods.
[0022]
(1) Measurement of breaking strength (T B ) A No. 3 dumbbell test piece was prepared according to JIS-K6251, and a tensile test was performed to measure the strength at break.
[0023]
(2) Demoldability Ten tires were produced for each example, and the state of tread chipping when the tire was taken out from the vulcanization mold was visually evaluated. The evaluation criteria are as follows.
[0024]
○: Tread chipping did not occur.
Δ: 1-4 pieces of tread were observed.
[0025]
X: 5 or more tread chips were observed.
Table 2 shows the results of evaluation of the carbon black content, breaking strength, and demoldability. In Table 2, the compounding amount of carbon black in the belt-like sheet is 65 parts by mass (Example 1) and 75 parts by weight (Example 2) that the demoldability is superior to 55 parts by weight (Comparative Example 1). I understand.
[0026]
[Table 1]
[Table 2]
Examples 3 to 5 and Comparative Example 2
Table 3 shows the relationship between the thickness of the belt-like sheet and the demolding property. Tires having the same specifications as in Example 2 were used except for the thickness of the belt-like sheet.
[0029]
[Table 3]
In Table 3, the thickness of the belt-like sheet is 0.5 mm (Example 3), 2 mm (Example 4), and 3 mm (Example 5) are more excellent in demolding than 0.3 mm (Comparative Example 2). Yes.
[0031]
Examples 6-11
Table 4 shows the relationship between the width (L) of the belt-like sheet and the steering stability. The belt-like sheet is shown for two types of thickness. Except for the width of the belt-like sheet, tires having the same specifications as in Example 2 were used.
[0032]
Here, the steering stability was evaluated by evaluating the steering wheel response by running each tire of the example. Relative evaluation was made with Example 6 as 6 points. The larger the value, the better the steering stability.
[0033]
[Table 4]
In Table 4, it can be seen that when L / TW × 100 is 60% or less, the steering stability is particularly excellent.
[0035]
【The invention's effect】
As described above, the present invention provides a surface of a tread rubber composition in which the blending amount of the filler is less than 65 parts by mass in the method for producing a pneumatic tire that is vulcanized using a split mold on the surface of the tread. An unvulcanized belt-like sheet having a rubber composition of 65 parts by mass or more, a thickness of 0.5 or more and 4.0 mm or less, and a rupture strength (T B ) after vulcanization of 20 MPa or more and 100 MPa or less. Since it coat | covered, a tread chip | tip can be reduced effectively.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of the right half of a pneumatic tire according to the present invention.
FIG. 2 is a partially enlarged view of the tread portion of FIG.
[Explanation of symbols]
1 Pneumatic tire, 2 carcass, 3 belt layers, 4 bead cores, 5 bead apex, 6 tread part, 7 tread groove, 8 strip sheet.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002360745A JP4262972B2 (en) | 2002-12-12 | 2002-12-12 | Pneumatic tire manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2002360745A JP4262972B2 (en) | 2002-12-12 | 2002-12-12 | Pneumatic tire manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2004188858A JP2004188858A (en) | 2004-07-08 |
| JP4262972B2 true JP4262972B2 (en) | 2009-05-13 |
Family
ID=32759739
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2002360745A Expired - Fee Related JP4262972B2 (en) | 2002-12-12 | 2002-12-12 | Pneumatic tire manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4262972B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5010456B2 (en) * | 2007-12-27 | 2012-08-29 | 住友ゴム工業株式会社 | Pneumatic tire |
| DE102011001939A1 (en) * | 2011-04-11 | 2012-10-11 | Continental Reifen Deutschland Gmbh | Vehicle tires |
| JP6613718B2 (en) * | 2015-08-25 | 2019-12-04 | 住友ゴム工業株式会社 | Tire manufacturing method |
-
2002
- 2002-12-12 JP JP2002360745A patent/JP4262972B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2004188858A (en) | 2004-07-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US7040369B2 (en) | Pneumatic radial tire | |
| KR100973542B1 (en) | tyre for vehicle wheels with tread band of cap and base construction | |
| JP4997038B2 (en) | Tread for retreaded tire and retreaded tire | |
| JP5057522B2 (en) | tire | |
| JP5768901B2 (en) | Pneumatic tire | |
| US5718782A (en) | Truck tire with cap/base construction tread | |
| JPH01317806A (en) | Tire and tread | |
| WO2009080144A1 (en) | Run-flat tire | |
| JP5364259B2 (en) | tire | |
| JP4502587B2 (en) | Pneumatic tire | |
| JP2006511386A (en) | Tires for motorcycles | |
| WO2012057356A1 (en) | Method for producing base tire and method for producing time | |
| JP4262972B2 (en) | Pneumatic tire manufacturing method | |
| EP2692544B1 (en) | Tire casing | |
| WO2010137143A1 (en) | Tire | |
| JP2007145242A (en) | Tire for construction vehicle | |
| EP2231422B1 (en) | Run-flat tire | |
| JPH07237405A (en) | Pneumatic radial tire | |
| EP1637359B1 (en) | Pneumatic tire | |
| KR20200067565A (en) | Rubber composition of tire groove, tire manufactured using the same and manufacturing method thereof | |
| WO2020230576A1 (en) | Pneumatic tire and method for manufacturing same | |
| JP2010269631A (en) | Pneumatic tire and vulcanization mold for pneumatic tire | |
| WO2013121778A1 (en) | Rubber composition for pneumatic-tire sidewalls, and pneumatic tire | |
| CN116829374A (en) | Self-supporting tyre for vehicle wheels | |
| JP2021003905A (en) | Pneumatic tire |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20050908 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20080417 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20080507 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20080701 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20090203 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20090210 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120220 Year of fee payment: 3 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120220 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130220 Year of fee payment: 4 |
|
| LAPS | Cancellation because of no payment of annual fees |