JPS6127703A - Radial tire improved in its durability on bad load - Google Patents
Radial tire improved in its durability on bad loadInfo
- Publication number
- JPS6127703A JPS6127703A JP59146744A JP14674484A JPS6127703A JP S6127703 A JPS6127703 A JP S6127703A JP 59146744 A JP59146744 A JP 59146744A JP 14674484 A JP14674484 A JP 14674484A JP S6127703 A JPS6127703 A JP S6127703A
- Authority
- JP
- Japan
- Prior art keywords
- weight
- parts
- rubber
- pts
- carbon black
- 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.)
- Pending
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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
- B60C1/00—Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition
- B60C1/0016—Compositions of the tread
Abstract
Description
【発明の詳細な説明】
（発明の技術分野）
本発明は悪路耐久性を改良したラジアルタイヤに関し、
より詳細には特に非舗装路、悪路を主体とするダンプト
ラックの要求特性、即ち摩耗、カットチッピング、発熱
等の総合的な悪路耐久性を改良したトレッドを有するト
ラック、バス用の空気入り大型スチールラジアルタイヤ
に関する。[Detailed Description of the Invention] (Technical Field of the Invention) The present invention relates to a radial tire with improved rough road durability.
In more detail, the characteristics required of dump trucks, which mainly operate on unpaved roads and rough roads, are pneumatic tires for trucks and buses with treads that have improved overall rough road durability such as wear, cut chipping, and heat generation. Regarding large steel radial tires.
大型ラジアルタイヤの中で、最も厳しい使用条件下に置
かれるダンプトラックの品質要求ニーズは、耐摩耗性や
耐トレッドセパレーション性（発熱特性）のみならず、
耐カツトチッピング性をも含めた総合的な悪路耐久性で
ある。Among large radial tires, the quality requirements for dump trucks, which are subjected to the most severe usage conditions, are not limited to wear resistance and tread separation resistance (heat generation properties).
This is overall rough road durability including cut chipping resistance.
即ちダンプユーザーにとって関心の強いタイヤ特性は、
ある程度の過荷重および高速性に耐え、舗装路、非舗装
路、悪路にかかわらず、トレッド表面にできる限り損傷
を受けることなく、寿命を全うすることである。In other words, the tire characteristics that are of great interest to dump truck users are:
The objective is to withstand a certain degree of overload and high speed, and to complete its lifespan with as little damage to the tread surface as possible, regardless of whether it is on paved roads, unpaved roads, or rough roads.
しかしながら、舗装路要求特性としての耐摩耗性と、悪
路あるいは非舗装路要求特性としての耐カツトチッピン
グ性の両立は難しく、高荷重ラジアルタイヤ要求特性と
しての耐久性までを含めると、単能的キ・ヤツプトレッ
ドでは複雑かつ多様化する市場要求を満足することが困
難であった。However, it is difficult to achieve both wear resistance, which is a characteristic required for paved roads, and cut chipping resistance, which is a characteristic required by rough roads or non-paved roads. It was difficult for the keyboard to satisfy the complex and diversifying market demands.
かかる問題点に対する解決策の一つとして、特公昭５４
−４２４８２号公報に示されているように、カーボンブ
ラック特性の適性化、即ちカーボン補強機構からの検討
があり、他方には特公昭５４−４３８３号公報に示され
るように、亜鉛華／ステアリン酸、および加硫促進剤／
硫黄の適性化、即ち架橋形態からの対応がある。As one of the solutions to this problem,
As shown in Japanese Patent Publication No. 42482, there is a study to optimize carbon black properties, that is, carbon reinforcement mechanism, and on the other hand, as shown in Japanese Patent Publication No. 54-4383, zinc white/stearic acid , and vulcanization accelerator/
There is a response from sulfur suitability, that is, from the crosslinked form.
しかしながら、近年、大型タイヤのラジアル化が高まっ
ている中で、トラック、バス用ラジアルタイヤの使用範
囲も拡大しつつあり、悪路耐久性は勿論のこと、高速性
、低燃費性等に関しても極限性能が要求されるため、単
にカーボン補強や架橋形態の最適、有効化だけでは対応
しきれない情勢にある。However, in recent years, as the use of radial tires for large tires has increased, the scope of use of radial tires for trucks and buses is also expanding, and not only durability on rough roads but also high speed, fuel efficiency, etc. As performance is required, it is no longer possible to meet this situation simply by optimizing and optimizing carbon reinforcement and crosslinking forms.
また、特願昭５８−２３５１８２号のように、二層また
は三層トレッド構造に特定の機能を有するゴム組成物を
配置する方法も提案されているが、一方では単一キャッ
プトレッド・ゴム組成物による極限性能の追究が強く望
まれている。Furthermore, as in Japanese Patent Application No. 58-235182, a method has been proposed in which a rubber composition having a specific function is placed in a two-layer or three-layer tread structure. There is a strong desire to pursue the ultimate performance by
ところで、悪路耐久性の中でも特に大型ラジＪ、
アルタイヤ性能として重要視されるのはミ耐カットチッ
ピング性能である。By the way, in terms of rough road durability, cut and chipping resistance is particularly important for large RAJ and AL tires.
本発明者等は、カットチッピング現象を多数の実車走行
デークーから、下記のように解明した。The present inventors elucidated the cut chipping phenomenon as follows from a large number of actual vehicle driving tests.
即ちカットチッピング現象は、採石や砂利が散乱する非
舗装路面をタイヤが走行するときに集中的に発生し、か
つかかる路面でブレーキングや成程度の速度条件下での
コーナリングが負荷され、繰り返されると、トレッドゴ
ムの表面が取り去られて生ずる現象である。In other words, the cut chipping phenomenon occurs intensively when tires run on unpaved roads littered with quarry stones and gravel, and is repeatedly subjected to braking and cornering at moderate speeds on such roads. This phenomenon occurs when the surface of the tread rubber is removed.
そしてこの現象を、トレッドゴム物性の面から見ると、
ゴム膨潤度から求められる網目鎖密度がタイヤ走行によ
る熱や応力疲労によって異常に増加し、破断伸びが低下
するという物性変化現象と対応ずけることができる。Looking at this phenomenon from the perspective of physical properties of tread rubber,
This can be correlated with the physical property change phenomenon in which the network chain density determined from the degree of rubber swelling increases abnormally due to heat and stress fatigue caused by tire running, and the elongation at break decreases.
しかも、かかる物性変化は、同一条件での走行において
は、はぼ類似していることから、いかなる走行条件でも
寿命を全うするには、走行末期においても、ゴム弾性を
保持すべく、出来る限り初期の網目鎖密度を低目に、即
ちゴム膨潤度を高目に設定し、破断伸びを確保すること
が必要であり、これこそがカットチッピングの発生を抑
えることを可能にすると考えられる。Moreover, such physical property changes are quite similar when running under the same conditions, so in order to complete the life under any running conditions, it is necessary to maintain the rubber elasticity even at the end of running. It is necessary to set the network chain density to a low value, that is, to set the rubber swelling degree to a high value to ensure elongation at break, and it is thought that this is the only way to suppress the occurrence of cut chipping.
一方、大型ラジアルタイヤ性能を摩耗特性の観点からみ
ると、ある程度のトレッド剛性がないとトレッド部全体
の変形が大きくなり、特に山間油路などのトレッド剛性
が要求されるような過酷条件下での耐摩耗性の低下に結
びついてしまうので、適性な剛性確保が必要となる。On the other hand, when looking at the performance of large radial tires from the perspective of wear characteristics, the deformation of the entire tread becomes large unless there is a certain degree of tread rigidity. This will lead to a decrease in wear resistance, so it is necessary to ensure appropriate rigidity.
このように、高荷重用大型ラジアルタイヤの総合的な悪
路耐久性を改良するトレッドゴム組成物を確立するには
、初期トレッドゴム物性として、ある程度のトレッド剛
性を保有し、かつできる限り高い初期膨潤度を有するト
レッドゴム組成物が必要であり、その為には下記の手段
が考えられる。In this way, in order to establish a tread rubber composition that improves the overall rough road durability of large radial tires for heavy loads, it is necessary to have a certain level of tread stiffness as the initial tread rubber physical properties and to have as high an initial level as possible. A tread rubber composition having a degree of swelling is required, and the following methods can be considered for this purpose.
イ、トレッド剛性を確保し、耐摩耗性を改良する手法と
して、有効な補強効果を発揮するようにカーボンブラッ
クの種類選定およびその量の適性化を図る。B. As a method to ensure tread rigidity and improve wear resistance, the type and amount of carbon black should be selected to provide an effective reinforcing effect.
即ち、カーボンブラックの粒径やストラフチャーのバラ
ンスと、それぞれのカーボンブラックの量的バランスを
含めて適性化を図ることによって、トレッドゴムのモジ
ュラスの最適化を図り、トレッド剛性を確保する。That is, the modulus of the tread rubber is optimized and tread rigidity is ensured by optimizing the balance of the particle size and stracture of carbon black, as well as the quantitative balance of each carbon black.
ロ、初期ゴム膨潤度を高目に設定し、カットデツピング
性を改良する手法としては、有効な架橋形態を取った配
合とする。B. As a method of improving the cut-depping property by setting the initial rubber swelling degree to a high level, the composition is formulated in an effective cross-linked form.
即ち、ゴムの網目鎖密度を決定する硫黄、加硫促進剤、
更にはステアリン酸の最適量化をは５かり、特に走行疲
労に伴う異方性の発生を抑えるために加硫促進剤／硫黄
比率およびそれらの全配合量を適性化する。Namely, sulfur, vulcanization accelerator, which determines the network chain density of rubber,
Furthermore, we aim to optimize the amount of stearic acid, and in particular, optimize the vulcanization accelerator/sulfur ratio and their total blending amount in order to suppress the occurrence of anisotropy associated with running fatigue.
本発明の目的は、特定のカーボンブラックを配合するこ
とによってカーボン補強効果を高め、一方では加硫剤や
加硫助剤を適性配合することによって架橋形態を有効化
させて、悪路耐久性を改良したラジアルタイヤを提供す
ることにある。The purpose of the present invention is to enhance the carbon reinforcing effect by blending a specific carbon black, and on the other hand, to improve the durability on rough roads by activating the crosslinking form by appropriately blending a vulcanizing agent and a vulcanization aid. The objective is to provide an improved radial tire.
上記目的を達成する本発明は、天然ゴム５０〜９０重量
部とポリイソプレンゴム５０〜１０重量部からなるブレ
ンドゴム１００重量部に対して、窒素比表面積１１５〜
１５０ Ｉｄ ／ ｇ、ジブチルフタレート吸収量１０
５〜１３０ｍｌ ／ １００ｇ、着色力１１０％以上の
カーボンブラック４０〜６０重量部、ヨウ素価５％以下
かつステアリン酸含有率５０％以上の脂肪酸０．５〜２
．５重量部、および硫黄１．０〜１．５重量部を配合し
てなり、金属酸化物または金属塩と前記脂肪酸との重量
比が２．５以上であり、かつ前記硫黄と加硫促進剤との
合計量が２．２重量部以上であるトレッドゴム組成物を
用いたことを特徴とするものである。The present invention, which achieves the above object, has a nitrogen specific surface area of 115 to 100 parts by weight of a blend rubber consisting of 50 to 90 parts by weight of natural rubber and 50 to 10 parts by weight of polyisoprene rubber.
150 Id/g, dibutyl phthalate absorption 10
5-130ml/100g, 40-60 parts by weight of carbon black with a tinting power of 110% or more, fatty acid 0.5-2 with an iodine value of 5% or less and a stearic acid content of 50% or more.
．． 5 parts by weight, and 1.0 to 1.5 parts by weight of sulfur, the weight ratio of the metal oxide or metal salt to the fatty acid is 2.5 or more, and the sulfur and the vulcanization accelerator. The invention is characterized by using a tread rubber composition in which the total amount of the tread rubber composition is 2.2 parts by weight or more.
本発明においては、まず天然ゴム５０〜９０重量部とポ
リイソプレンゴム５０〜１０重量部からなるブレンドゴ
ムがトレッドゴム組成物のベースとなる。In the present invention, a blended rubber consisting of 50 to 90 parts by weight of natural rubber and 50 to 10 parts by weight of polyisoprene rubber serves as the base of the tread rubber composition.
ここでポリイソプレンゴムとしては、シス−１，４−結
合が７０％以上で、平均分子量が６０万〜１２０万のも
のが用いられる。The polyisoprene rubber used here has a cis-1,4-bond content of 70% or more and an average molecular weight of 600,000 to 1,200,000.
シス−１，４−結合が７０％に満たないと、ゴムノ発＝
カ高＜なり、耐トレッドセパレーション性が低下し好ま
しくない。If the cis-1,4-bond is less than 70%, rubber formation =
This is not preferable because the force becomes too high and the tread separation resistance decreases.
また、平均分子量が６０万に満たないと、発熱高および
破断強度特性低下を引き起し、一方、１２０万を綽える
と、混合や押し出し等の加工性の点で硬くなるので好ま
しくない。Furthermore, if the average molecular weight is less than 600,000, it will cause high heat generation and a decrease in breaking strength properties, while if it is less than 1,200,000, it will become hard in terms of processability such as mixing and extrusion, which is not preferable.
となるので好ましくない。This is not desirable.
かかるブレンドゴム１００重量部に対して、本発明にお
いては特定の物性を有するカーボンブラックを４０〜６
０重量部、好ましくは４５〜５５重量部を配合する。In the present invention, 40 to 6 parts of carbon black having specific physical properties are added to 100 parts by weight of such blended rubber.
0 parts by weight, preferably 45 to 55 parts by weight.
カーボンブラックの配合量が４０重量部より少ないと、
得られたラジアルタイヤの耐摩耗性および耐カット性が
劣り、また６０重量部を越えると耐チッピング性および
発熱性が劣るので好ましくない。If the amount of carbon black is less than 40 parts by weight,
The wear resistance and cut resistance of the obtained radial tire are poor, and if it exceeds 60 parts by weight, the chipping resistance and heat generation properties are undesirable.
本発明で用いる特定の物性を有するカーボンブラックと
は、窒素比表面積（以下、Ｎ２Ｓ＾と略記する）力（１
１５〜１５０ ｒｒｒ／ｇであり、ジブチルフタレート
吸収量（以下、ＤＢＰと略記する）が１０５〜１３０ｍ
ｇ ／１００ｇであり、着色力が１１０％以上の高補強
性カーボンブラックである。Carbon black having specific physical properties used in the present invention refers to nitrogen specific surface area (hereinafter abbreviated as N2S^) force (1
15 to 150 rrr/g, and the dibutyl phthalate absorption amount (hereinafter abbreviated as DBP) is 105 to 130 m
g/100g, and is a highly reinforcing carbon black with a tinting strength of 110% or more.
カーボンブラックは補強効果に重要な役割を有するもの
であり、Ｎ２５Ａを大きくする、即ち粒子径を小さくす
る、或いはＤＢＰを大きくする、即ちストラフチャーを
大きくすることで耐摩耗性の向上が期待できるものの耐
カツトチッピング性を低下させることが知られている。Carbon black plays an important role in the reinforcing effect, and although it is expected that wear resistance will be improved by increasing N25A, that is, decreasing the particle size, or increasing DBP, that is, increasing the struture, It is known to reduce cut chipping properties.
それ故、前記特公昭５４−４２４８２号では、粒子径を
できるだけ小さく設定しつつ、ストラフチャーを低目に
設定する手法を採用しているが、粒子径とストラフチャ
ーの耐摩耗性向上効果を詳細に検討してみると、ストラ
フチャーの効果の方が強く現れる。Therefore, in the above-mentioned Japanese Patent Publication No. 54-42482, a method is adopted in which the particle size is set as small as possible and the strafture is set to a low value, but the effect of improving the wear resistance of the particle size and the strafture is studied in detail. As a result, the effect of strafture appears stronger.
そして、ＤＢＰが１０５ｍｌ ／１００ｇに満たないと
、いくらＮ２５Ａを高目に設定したとしても耐摩耗性に
関する極限性能を満足することができず、一方、ＤＢＰ
が１３０ｍｇ ／１００ｇを越えると、耐チッピング性
が著しく低下するので好ましくない。If the DBP is less than 105ml/100g, no matter how high the N25A is set, it will not be possible to satisfy the ultimate performance regarding wear resistance.
If it exceeds 130 mg/100 g, the chipping resistance will be significantly reduced, which is not preferable.
マタ、粒子径ニツイテも、Ｎ、ＳＡが１１５ ｎ？／ｇ
に満たないと耐摩耗性が低下し、一方、１５０ ％／ｇ
を越えると発熱特性や加工性の点で問題を生ずる。Also, the particle size is 115 n? /g
If the wear resistance is less than 150%/g, the wear resistance decreases.
Exceeding this will cause problems in terms of heat generation characteristics and workability.
更にカーボンブラックの着色力力’１１’０ ％より少
ないと引裂抵抗が低下し、耐カツトチッピング性の低下
を引き起す。Furthermore, if the tinting power of carbon black is less than 0%, tear resistance decreases, causing a decrease in cut chipping resistance.
しかしながら、以上のような耐カット性、耐チッピング
性、更には発熱性を考慮し、かつ補強効果に裏付けられ
た耐摩耗性向上を目的としたカーボンブラック配合だけ
では、ラジアルタイヤの極限性能を満足することはでき
ない。However, considering the cut resistance, chipping resistance, and heat generation properties mentioned above, and with the aim of improving wear resistance backed by reinforcing effects, it is not enough to satisfy the ultimate performance of radial tires. I can't.
そこで本発明においては、他の重要な役割を有する架橋
形態との組合せの中で、極限性能を満足すべく、硫黄、
加硫促進剤などの加硫剤や、亜鉛華やステアリン酸など
の加硫助剤の配合量およびその配合比率について検討し
た。Therefore, in the present invention, in order to satisfy the ultimate performance, sulfur,
The amounts and ratios of vulcanizing agents such as vulcanization accelerators and vulcanizing aids such as zinc white and stearic acid were investigated.
そして、これら個々の配合剤を所定量配合す゛ることに
よって、良路はもちろん、悪路における耐摩耗性、耐カ
ツトチッピング性、発熱性などの総合的な悪路耐久性に
ついて極限性能を満足するに至った。By blending these individual ingredients in predetermined amounts, it is possible to satisfy the ultimate performance in terms of overall rough road durability such as wear resistance, cut chipping resistance, heat generation property, etc. not only on good roads but also on rough roads. It's arrived.
即ち本発明においては、前記ブレンドゴムの１００重量
部に対してヨウ素価５％以下、かつステアリン酸含有率
５０％以上の脂肪酸を０．５〜２．５重量部配合する。That is, in the present invention, 0.5 to 2.5 parts by weight of fatty acids having an iodine value of 5% or less and a stearic acid content of 50% or more are blended with respect to 100 parts by weight of the blended rubber.
一般に、ステアリン酸などの脂肪酸の配合量を減らして
ゆくと、引張特性を著しく低下させる他、ｔａｎ δの
温度依存性が小さくなり、高温時のｔａｎ δが上昇す
るために、トレッドゴム自体の発熱を著しく高めるなど
、タイヤ耐久性に悪影響を及ぼすことが知られている。Generally, as the content of fatty acids such as stearic acid is reduced, the tensile properties are significantly reduced, and the temperature dependence of tan δ becomes smaller, increasing tan δ at high temperatures, which increases the heat generation of the tread rubber itself. It is known to have a negative effect on tire durability, such as by significantly increasing the
しかしながら、一方でゴム膨潤度を著しく高め、初期の
網目鎖密度を低めに設定すること力弐できることから、
耐チツ“ピング性に対して効果的である。However, on the other hand, it is possible to significantly increase the rubber swelling degree and set the initial network chain density to a low value.
Effective for chipping resistance.
即ち、脂肪酸の配合量が０．５重量部に満たないとｔａ
ｎ δが高くなりすぎ、発熱特性面で好ましくない。ま
た、２．５重量部を越えるとゴム膨潤度に対して効果的
でない。That is, if the amount of fatty acid blended is less than 0.5 parts by weight, ta
n δ becomes too high, which is unfavorable in terms of heat generation characteristics. Moreover, if it exceeds 2.5 parts by weight, it is not effective for controlling the rubber swelling degree.
また、ヨウ素価が５％を越えると、加硫速度が著しく遅
れ発熱を高めるため、耐トレッドセパレーション性が低
下し、ステアリン酸含有率が５０％に満たないと、ステ
アリン酸亜鉛などの金属塩のブルーム速度が大きくなり
、成型工程上問題となる。In addition, if the iodine value exceeds 5%, the vulcanization rate will be significantly delayed and heat generation will increase, resulting in a decrease in tread separation resistance.If the stearic acid content is less than 50%, metal salts such as zinc stearate will The blooming speed increases, causing problems in the molding process.
なお脂肪酸としては、ステアリン酸、オレイン酸、ラウ
リル酸、パルミチン酸等が用（、ｓられ、好ましくはス
テアリン酸が用いられる。As the fatty acid, stearic acid, oleic acid, lauric acid, palmitic acid, etc. are used, and stearic acid is preferably used.
本発明における、このような脂肪酸配合量が少ない範囲
では、亜鉛華などの金属酸化物、またはステアリン酸亜
鉛などの金属塩の配合量設定が重要であり、本発明にお
いては脂肪酸／金属酸化物または脂肪酸／金゛属塩の比
率が２．５以上であり、ゴム膨潤度を高目に維持しつつ
、発熱特性などの動的疲労性を向上させることができる
。In the present invention, in such a range where the amount of fatty acids blended is small, it is important to set the amount of metal oxides such as zinc white or metal salts such as zinc stearate. The ratio of fatty acid/metallic salt is 2.5 or more, and dynamic fatigue properties such as heat generation properties can be improved while maintaining a high degree of rubber swelling.
金属酸化物としては、亜鉛華以外に酸化マグネシウム等
が用いられ、金属塩としてはステアリン酸亜鉛以外に、
ステアリン酸マグネシウム等が用いられる。４
更に本発明においては、前記ブレンドゴムの１００重量
部に対して硫黄を１．０〜１．５重量部配合すると共に
、加硫促進剤と硫黄との合計配合量がブレンドゴム１０
０重量部に対して２．２重量部以上になるようにする。In addition to zinc white, magnesium oxide is used as a metal oxide, and as a metal salt, in addition to zinc stearate,
Magnesium stearate and the like are used. 4 Furthermore, in the present invention, 1.0 to 1.5 parts by weight of sulfur is blended with respect to 100 parts by weight of the blended rubber, and the total blended amount of the vulcanization accelerator and sulfur is 10 parts by weight of the blended rubber.
The amount should be 2.2 parts by weight or more compared to 0 parts by weight.
このような範囲に硫黄を配合すれば、前記のように脂肪
酸の配合量が少ない領域でも、引張特性を高目に維持す
ると共にゴムの網目鎖密度を低目に維持することができ
、更には走行特性を伴う異方性の発生を抑制するうえで
も効果的であり、耐摩耗性と耐カツトチッピング性とい
う、従来では相反するとされていた両特性を両立させる
こたとができる。By blending sulfur in this range, it is possible to maintain high tensile properties and maintain a low network chain density of the rubber even in the range where the amount of fatty acid blended is small as described above. It is also effective in suppressing the occurrence of anisotropy that accompanies running characteristics, and can achieve both wear resistance and cut chipping resistance, which were conventionally considered to be contradictory properties.
以下に本発明の組成物を構成する各成分の物性値測定゛
方法を示す。The method for measuring the physical properties of each component constituting the composition of the present invention will be shown below.
窒素比表面積・−ＡＳＴＭ Ｄ ３０３７Ｂ法にも
とすいたもので、単分子層を形成するのに必要な窒素ガ
ス量を求めることにより測定される。Nitrogen specific surface area - This is also applicable to the ASTM D 3037B method, and is measured by determining the amount of nitrogen gas required to form a monomolecular layer.
ジブチルフタレート吸収量−・・Ｊ Ｉ Ｓ ｘ−６２
２１にもとすき、乾燥カーボン１００ｇに対するジブチ
ルフタレート吸収量（ｍｌ）を算出したものであり、そ
の値が大きい程、ストラフチャーの高いカーボンを示す
。Dibutyl phthalate absorption amount--J I S x-62
In 21, the amount of dibutyl phthalate absorbed (ml) per 100 g of dry carbon was calculated, and the larger the value, the higher the strutness of the carbon.
着色カー Ｊ Ｉ Ｓ Ｋ−６２２１にもとすき、光
学反射針（Ｗｅｌｃｈ ５ｃｉｅｎｔｉｆｉ’ｃ Ｃｏ
、）で反射率を測定し、標準ブラック ＩＲＢ＃３に対
する比率を示したもので、一般に粒子径やストラフチャ
ーの分布状況に影響される。Optical reflective needle (Welch 5cientifi'c Co., Ltd.)
, ), and shows the ratio to standard black IRB #3, which is generally influenced by the particle size and the distribution of stractures.
ヨウ素価・−・Ｊ Ｉ Ｓ Ｋ−３３４１にもとずき
Ｎ／１０チオ硫酸ナトリウム溶液の滴定評価より求めた
。Iodine value: Determined by titration evaluation of N/10 sodium thiosulfate solution based on JIS K-3341.
ステアリン酸含有率−・ガスクロマトグラフ測定により
求めた。Stearic acid content - Determined by gas chromatography.
以上述べたように本発明のラジアルタイヤは、天然ゴム
５０〜９０重量部とポリイソプレンゴム５０〜１０重量
部からなるブレンドゴム１００重量部に対して、窒素比
表面積１１５〜１５０ｎ？／ｇ、ジブチルフタレート吸
収量１０５〜１３０ｍｌ ／１００ｇ、着色力１１０％
以上のカーボンブラック４０〜６０Ｍ量部、ヨウ素価５
％以下かつステアリン酸含有率５′Ｏ％以上の脂肪酸０
．５〜２．５重量部、および硫黄１．０〜１．５重量部
を配合してなり、かつ金属酸化物または金属塩と前記脂
肪酸との重量比を２．５以上、前記硫黄と加硫促進剤と
の合計量が２．２重量部以上であるトレッドゴム組成物
を用いたので、耐摩耗性、耐カツトチッピング、更には
発熱性等の悪路耐久性を改良したラジアルタイヤを得る
ことができる。As described above, the radial tire of the present invention has a nitrogen specific surface area of 115 to 150 n? with respect to 100 parts by weight of a blend rubber consisting of 50 to 90 parts by weight of natural rubber and 50 to 10 parts by weight of polyisoprene rubber. /g, dibutyl phthalate absorption 105-130ml /100g, coloring power 110%
40 to 60 M parts of carbon black, iodine value 5
% or less and stearic acid content 5'O% or more fatty acids 0
．． 5 to 2.5 parts by weight, and 1.0 to 1.5 parts by weight of sulfur, and the weight ratio of the metal oxide or metal salt to the fatty acid is 2.5 or more, and the sulfur and the vulcanized By using a tread rubber composition in which the total amount including the accelerator is 2.2 parts by weight or more, it is possible to obtain a radial tire with improved wear resistance, cut chipping resistance, and durability on rough roads such as heat generation. I can do it.
かかるラジアルタイヤは、バス、トラック、特にダンプ
トラック用のラジアルタイヤとして好適である。Such a radial tire is suitable as a radial tire for buses, trucks, and especially dump trucks.
以下、本発明の実施例を述べる。Examples of the present invention will be described below.
実施例１〜６
天然ゴムとポリイソプレンゴムのブレンドゴム１００重
量部に対して、ＣＢ−３のカーボンブラックを５０重量
部、ホワイトカーボン１０重量部を配合し、更に亜鉛華
、ステアリン酸、加硫促進剤および硫黄を適量部配合し
てなるゴム組成物をキャップトレッドとして用い、カー
カスおよびベルトがスチールコード層からなる１０００
Ｒ２０，１４ＰＲ、ラグタイプのスチールラジアルタイ
ヤを製造し、耐摩耗性、耐カツトチッピング性および耐
久性について評価・試験を行った。結果を下記第１表に
、カーボンブラックの性質を第２表に示す。Examples 1 to 6 50 parts by weight of CB-3 carbon black and 10 parts by weight of white carbon were blended with 100 parts by weight of blended rubber of natural rubber and polyisoprene rubber, and zinc white, stearic acid, and vulcanization were added. A rubber composition containing an appropriate amount of an accelerator and sulfur is used as the cap tread, and the carcass and belt are made of a steel cord layer.
R20,14PR, lug-type steel radial tires were manufactured and evaluated and tested for wear resistance, cut chipping resistance, and durability. The results are shown in Table 1 below, and the properties of the carbon black are shown in Table 2.
比較例１〜１６
天然ゴム１００重量部に対して各種カーボンブラックを
それぞれ５０重量部配合し、更にホワイトカーボン１０
重量部、亜鉛華３重量部、ステアリン酸３重量部、老化
防止剤１重量部、加硫促進剤１．０重量部および硫黄１
．０重量部を配合してなるゴム組成物を用い、実施例１
と同様にタイヤを製造し、評価試験を行った。Comparative Examples 1 to 16 50 parts by weight of each type of carbon black was blended with 100 parts by weight of natural rubber, and 10 parts by weight of white carbon was added.
parts by weight, 3 parts by weight of zinc white, 3 parts by weight of stearic acid, 1 part by weight of anti-aging agent, 1.0 part by weight of vulcanization accelerator, and 1 part by weight of sulfur.
．． Example 1 using a rubber composition containing 0 parts by weight
Tires were manufactured in the same manner as above, and evaluation tests were conducted.
結果を第１゛表に）カーボンブラックの性質を第２表に
併記する。The results are shown in Table 1) The properties of carbon black are also shown in Table 2.
なお、第１表における物性値の測定方法は下記のとおり
である。The method for measuring the physical property values in Table 1 is as follows.
３００％モジュラス、ＥＬ （破断伸び） 、Ｈｓ （
硬さ）はＪＩＳ Ｋ２ＳＯ３法に従って測定した。300% modulus, EL (elongation at break), Hs (
Hardness) was measured according to the JIS K2SO3 method.
ｔａｎ δは動的粘弾性測定機を用い、振動数２０Ｈｚ
、動歪１０％±２％、温度１ｏｏ℃の条件で測定し、比
較例１および８を１００とした指数で表示した。値が大
きい程、発熱特性が良好で、耐トレッドセパレーション
性が良好であることを示している。Tan δ was measured using a dynamic viscoelasticity measuring machine at a frequency of 20 Hz.
, a dynamic strain of 10%±2%, and a temperature of 100° C., and expressed as an index with Comparative Examples 1 and 8 set as 100. The larger the value, the better the heat generation characteristics and the better the tread separation resistance.
摩耗Ｉｎｄｅｘ値は、比較例１および８を１００とした
際の指数値であり、その摩耗量はランボーン摩耗試験機
でスリップ率を２５％と３５％とした２条件で測定した
。The wear index value is an index value when Comparative Examples 1 and 8 are taken as 100, and the wear amount was measured using a Lambourn abrasion tester under two conditions with a slip ratio of 25% and 35%.
ゴム膨潤度（Ｖｃ）は、ゴム片をベンゼン溶媒中に４８
時間浸漬した後の体積膨潤度を示しており、値が大きい
程、網目鎖密度が小さく、耐カツトチッピング性が優れ
ていることを表す。The degree of rubber swelling (Vc) is 48 when a piece of rubber is placed in a benzene solvent.
It shows the degree of volumetric swelling after being immersed for a period of time, and the larger the value, the lower the network chain density and the better the cut chipping resistance.
耐久性は、下記第３表に示す時間ステップで荷重を増加
させ、５５Ｋｍ／ＨＲの一定速度で走行させ、どの時間
ステップで故障に至るかの、いわゆるＦＭＶ・Ｓ Ｓ
Ｎｏ、 １１９の条件に従う室内耐久試験を実施し、比
較例１および比較例８を１００として指数表示した。耐
久性の優れるもの程、大きい値を示す。Durability is measured by increasing the load at the time steps shown in Table 3 below, driving at a constant speed of 55 km/HR, and determining at which time step failure occurs.
An indoor durability test was conducted under the conditions of No. 119, and Comparative Example 1 and Comparative Example 8 were set as 100 and expressed as an index. The better the durability, the larger the value.
第３表
耐摩耗性は、平均速度５５Ｋｍ／ＨＲ１荷重１２０％、
舗装率約９９％の良路ユーザーと、平均速度３０１ｆ／
ＨＲ１荷重１４０％、非舗装率２０％以上の悪路ユーザ
ーで実車テストを実施し、残湯３．２＋ｎ／ｍになるま
での走行距離を、比較例１および比較例８を１００とし
た指数で示した。Table 3 wear resistance is average speed 55km/HR1 load 120%,
Users on good roads with a paved rate of approximately 99% and an average speed of 301f/
An actual vehicle test was conducted using a user on a rough road with an HR1 load of 140% and an unpaved rate of 20% or more, and the distance traveled until the residual hot water reached 3.2 + n/m was calculated using an index with Comparative Example 1 and Comparative Example 8 as 100. Indicated.
値が大きい程、耐摩耗性が良好で、タイヤ寿命が長いこ
とを示す。The larger the value, the better the wear resistance and the longer the tire life.
耐カット性、耐チッピング性については、上記悪路ユー
ザーで外観チェックを実施し、耐カット性はトレッド表
面に入った外傷の数で、一方、耐チッピング性はトレッ
ド表面の剥離現象の発生度で評価し、比較例１および比
較例８を１００として場合の比率として算出した。Regarding cut resistance and chipping resistance, we conducted an appearance check on the rough road users mentioned above, and found that cut resistance is measured by the number of external injuries that enter the tread surface, while chipping resistance is measured by the degree of occurrence of peeling phenomena on the tread surface. The ratio was calculated using Comparative Example 1 and Comparative Example 8 as 100.
数値が大きいもの程、耐カット性、耐チッピング性が優
れていることを示す。The larger the value, the better the cut resistance and chipping resistance.
第１表から明らかなように、ＣＢ−１の低ストラクチヤ
ーカーボンでは、トレッド剛性の不足から摩耗およびカ
ット性能が著しく低下し、逆にＣＢ−４の高ストラクチ
ヤーカーボンではチッピング性能が著しく低下した。As is clear from Table 1, the wear and cutting performance of CB-1's low structure carbon significantly decreased due to the lack of tread rigidity, while the chipping performance of CB-4's high structure carbon decreased significantly. .
また、ＣＢ−２の小粒径カーボンでは特に耐久性が劣り
、実車テストでも良路において全数トレッドセパレーシ
ョンが発生した。In addition, the small particle size carbon of CB-2 was particularly poor in durability, and tread separation occurred in all of the tires on good roads in actual vehicle tests.
一方、粒径とストラフチャーとをバランスさせたＣＢ−
３，５および６では、耐摩耗性、耐カット性、耐チッピ
ング性、更には耐久性をバランス良くさせるものの、極
限性能を満足させるまでには至っていない。On the other hand, CB-
Nos. 3, 5, and 6 provide a good balance of abrasion resistance, cut resistance, chipping resistance, and even durability, but do not reach the point where the ultimate performance is satisfied.
そこで、ＣＢ−３のカーボンブラックを中ｔｃｓＪｔこ
、加硫剤と加硫助剤との変量実験を行ったところ、第１
表、比較例９〜１１のように脂肪酸の多い系では加硫剤
を増やすと、確かにトレッドセパレーションに対しては
有効に働くものの、チッピング性能を著しく低下させる
。Therefore, when we conducted a variable experiment using CB-3 carbon black, vulcanizing agent, and vulcanizing aid, we found that the first
As shown in Table 1, Comparative Examples 9 to 11, in systems containing a large amount of fatty acids, increasing the amount of vulcanizing agent does work effectively against tread separation, but it significantly reduces chipping performance.
ただし、比較例１４のように、金属塩を減らしすぎると
、発熱特性を低下させる。However, as in Comparative Example 14, if the metal salt is reduced too much, the exothermic properties will deteriorate.
また、比較例１３のように脂肪酸の少ない系で、かつ加
硫剤も減らしてゆくと、チッピング性能は良好であるも
のの、トレッドセパレーションを誘発し、かつトレッド
剛性不足から摩耗およびカット性能を著しく低下させて
しまい、好ましくない。In addition, when using a system with less fatty acids and reducing the amount of vulcanizing agent as in Comparative Example 13, although chipping performance is good, tread separation is induced and wear and cutting performance are significantly reduced due to lack of tread rigidity. I don't like it because I let it happen.
このように、カーボンブラックと加硫剤および加硫助剤
とを、たとえば実施例１〜６のように最適化することに
よって、総合的な悪路耐久性に関する極限性能を得るこ
とができる。In this way, by optimizing the carbon black, the vulcanizing agent, and the vulcanizing aid as in Examples 1 to 6, it is possible to obtain the ultimate performance regarding overall rough road durability.
（以下、余白）(Hereafter, margin)
Claims (1)
１０重量部からなるブレンドゴム１００重量部に対して
、窒素比表面積１１５〜１５０ｍ＾２／ｇ、ジブチルフ
タレート吸収量１０５〜１３０ｍｌ／１００ｇ、着色力
１１０％以上のカーボンブラック４０〜６０重量部、ヨ
ウ素価５％以下かつステアリン酸含有率５０％以上の脂
肪酸０．５〜２．５重量部、および硫黄１．０〜１．５
重量部を配合してなり、金属酸化物または金属塩と前記
脂肪酸との重量比が２．５以上であり、かつ前記硫黄と
加硫促進剤との合計量が２．２重量部以上であるトレッ
ドゴム組成物を用いたことを特徴とする悪路耐久性を改
良したラジアルタイヤ。50 to 90 parts by weight of natural rubber and 50 to 90 parts by weight of polyisoprene rubber
100 parts by weight of blended rubber consisting of 10 parts by weight, nitrogen specific surface area 115 to 150 m^2/g, dibutyl phthalate absorption amount 105 to 130 ml/100 g, 40 to 60 parts by weight of carbon black with a tinting power of 110% or more, and iodine. 0.5 to 2.5 parts by weight of fatty acids with a value of 5% or less and a stearic acid content of 50% or more, and 1.0 to 1.5 parts of sulfur.
parts by weight, the weight ratio of the metal oxide or metal salt to the fatty acid is 2.5 or more, and the total amount of the sulfur and the vulcanization accelerator is 2.2 parts by weight or more. A radial tire with improved durability on rough roads, characterized by using a tread rubber composition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59146744A JPS6127703A (en) | 1984-07-17 | 1984-07-17 | Radial tire improved in its durability on bad load |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59146744A JPS6127703A (en) | 1984-07-17 | 1984-07-17 | Radial tire improved in its durability on bad load |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS6127703A true JPS6127703A (en) | 1986-02-07 |
Family
ID=15414609
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59146744A Pending JPS6127703A (en) | 1984-07-17 | 1984-07-17 | Radial tire improved in its durability on bad load |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6127703A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01118550A (en) * | 1987-11-02 | 1989-05-11 | Toyo Tire & Rubber Co Ltd | Tire |
| JP2002053701A (en) * | 2000-08-08 | 2002-02-19 | Yokohama Rubber Co Ltd:The | Rubber composition for tire |
| JP2013040264A (en) * | 2011-08-12 | 2013-02-28 | Sumitomo Rubber Ind Ltd | Rubber composition for tire, production method thereof, and pneumatic tire |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52101503A (en) * | 1976-02-21 | 1977-08-25 | Bridgestone Corp | Pneumatic tire with improved tread |
| JPS547450A (en) * | 1977-06-20 | 1979-01-20 | Kuraray Co Ltd | Production of rubber composition with high unvulcanized strength |
| JPS5513724A (en) * | 1978-07-17 | 1980-01-30 | Yokohama Rubber Co Ltd:The | Rubber composition |
| JPS55132305A (en) * | 1979-12-17 | 1980-10-15 | Ohtsu Tire & Rubber Co Ltd | Tire |
-
1984
- 1984-07-17 JP JP59146744A patent/JPS6127703A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52101503A (en) * | 1976-02-21 | 1977-08-25 | Bridgestone Corp | Pneumatic tire with improved tread |
| JPS547450A (en) * | 1977-06-20 | 1979-01-20 | Kuraray Co Ltd | Production of rubber composition with high unvulcanized strength |
| JPS5513724A (en) * | 1978-07-17 | 1980-01-30 | Yokohama Rubber Co Ltd:The | Rubber composition |
| JPS55132305A (en) * | 1979-12-17 | 1980-10-15 | Ohtsu Tire & Rubber Co Ltd | Tire |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01118550A (en) * | 1987-11-02 | 1989-05-11 | Toyo Tire & Rubber Co Ltd | Tire |
| JP2002053701A (en) * | 2000-08-08 | 2002-02-19 | Yokohama Rubber Co Ltd:The | Rubber composition for tire |
| JP4496622B2 (en) * | 2000-08-08 | 2010-07-07 | 横浜ゴム株式会社 | Rubber composition for tire |
| JP2013040264A (en) * | 2011-08-12 | 2013-02-28 | Sumitomo Rubber Ind Ltd | Rubber composition for tire, production method thereof, and pneumatic tire |
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