JP2004300361A

JP2004300361A - Unvulcanized rubber composition for tire and tire

Info

Publication number: JP2004300361A
Application number: JP2003097643A
Authority: JP
Inventors: Kentaro Nishioka; 健太郎西岡
Original assignee: Toyo Tire and Rubber Co Ltd
Current assignee: Toyo Tire Corp
Priority date: 2003-04-01
Filing date: 2003-04-01
Publication date: 2004-10-28

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire that has excellent ozone resistance at a high temperature and shows good appearance without causing blooming (whitening), even when it is stored under a high-temperature condition, and provide an unvulcanized rubber composition to be used for producing tires. <P>SOLUTION: The unvulcanized rubber composition for tires comprises 100 pts.wt. of a diene rubber material and 0.8-8 pts.wt. of hydrocarbon wax. In the hydrocarbon wax, the total amount of 38-53C straight chain saturated hydrocarbons and 42-51C branched chain saturated hydrocarbons is from 5 wt.% through <15 wt.% and the hydrocarbon wax contains 20-30 wt.% of 25-40C branched saturated hydrocarbons. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、タイヤ用未加硫ゴム組成物及び該ゴム組成物を少なくとも一部に使用して加硫、成形して得られるタイヤに関する。より具体的には、高温での耐オゾン性に優れ、かつ高温条件下で長期間保存した場合であっても外観性に優れるタイヤ、及び該タイヤに用いられるタイヤ用未加硫ゴム組成物に関する。
【０００２】
【従来の技術】
従来から、天然ゴムや合成ゴムからなるタイヤには、大気中のオゾンや日光中の紫外線によるゴムの亀裂防止、すなわち、オゾン劣化防止のために、ワックス系ゴム老化防止剤が用いられている。しかしながら、このような老化防止剤を用いた場合、ゴム表面でブルーム現象が生じ、老化防止剤が表面ににじみ出てくることによりタイヤが白色化して外観性が低下するという問題があった。
【０００３】
このようなブルーム現象を抑制するために多くの技術が提案されている。例えば、天然ゴムやジエン系合成ゴム１００重量部に対し、炭化水素系ワックス０．１〜１０重量部を配合してなるゴム組成物であって、該炭化水素系ワックスの成分組成が、炭素数２９〜３９の非直鎖状成分の炭素数２８〜３６の直鎖状成分に対する割合が２０〜５５重量％であり、上記成分の合計量が３０〜６５重量％、炭素数２０〜２５の直鎖状及び非直鎖状の成分の合計量が７〜３０重量％、炭素数３８〜５３の直鎖状成分と炭素数４２〜５１の非直鎖状成分の合計量が１５〜３５重量％、及び炭素数３２〜４６の直鎖状成分と炭素数３８〜４６の非直鎖状成分の合計量が６０重量％以下であるゴム組成物、並びに該ゴム組成物を外皮部材に用いた空気入りタイヤが開示されている（特許文献１）。
【０００４】
【特許文献１】
特開平１１−２４６７０６号公報
【発明が解決しようとする課題】
しかし、特許文献１に記載の炭化水素系ワックスは、高温での耐オゾン性の効果が十分でなく、また該ワックスを含有するタイヤを高温条件下で長期間保存した場合にタイヤ表面が白色化する現象（ブルーム現象）を効果的に抑制することができず、タイヤの外観性に問題が生じる。
【０００５】
本発明の目的は、高温での耐オゾン性に優れ、かつ高温条件下で保存した場合であってもブルーム現象（白色化）が生じることのない外観性に優れるタイヤ、及び該タイヤに用いられるタイヤ用未加硫ゴム組成物を提供することにある。
【０００６】
【課題を解決するための手段】
本発明者は、上記目的を達成すべく、タイヤ用未加硫ゴム組成物について鋭意研究したところ、特定炭素数の飽和炭化水素を特定量含有する炭化水素系ワックスを用いることにより、上記目的を達成できることを見出し、本発明を完成するに至った。
【０００７】
即ち、本発明のタイヤ用未加硫ゴム組成物は、ジエン系ゴム材料１００重量部に対して炭化水素系ワックスを０．５〜８重量部含有し、前記炭化水素系ワックス中の炭素数３８〜５３の直鎖状飽和炭化水素と炭素数４２〜５１の分岐状飽和炭化水素との合計重量が前記炭化水素系ワックス全体の５重量％以上１５重量％未満であり、かつ前記炭化水素系ワックスは炭素数２５〜４０の分岐状飽和炭化水素を２０〜３０重量％含有することを特徴とする。
【０００８】
炭化水素系ワックスの添加量が０．５重量部未満の場合には高温での耐オゾン性が劣り、一方、８重量部を超える場合には高温条件下でブルーム現象が起こり、タイヤの外観性が低下する。両性能をさらに向上させるためには、炭化水素系ワックスの添加量は１〜５重量部であることが好ましい。
【０００９】
また、炭化水素系ワックス中の炭素数３８〜５３の直鎖状飽和炭化水素と炭素数４２〜５１の分岐状飽和炭化水素との合計重量が該ワックス全体の５重量％未満の場合には高温時における耐オゾン性が不十分であり、一方、１５重量％以上の場合には高温時にタイヤ表面の白色化が起こり、外観性が低下する。炭化水素系ワックス中の炭素数３８〜５３の直鎖状飽和炭化水素と炭素数４２〜５１の分岐状飽和炭化水素との合計重量は該ワックス全体の７〜１４重量％であることが好ましい。
【００１０】
また、炭化水素系ワックス中の炭素数２５〜４０の分岐状飽和炭化水素の含有量が２０重量％未満の場合には、タイヤ表面の白色化が起こり、外観性が低下する。一方、３０重量％を超える場合には、高温時における耐オゾン性が不十分となる。炭化水素系ワックスは炭素数２５〜４０の分岐状飽和炭化水素を２０〜２５重量％含有することが好ましい。
【００１１】
本発明のタイヤは、前記タイヤ用未加硫ゴム組成物を少なくとも一部に使用して加硫、成形して得られるものであることを特徴とする。かかるタイヤは、従来よりも優れた耐オゾン性及び外観性を有するものである。特に発熱の大きな部位であるトレッド部、サイドウォール部、ビード部等の構成材料として使用することにより、高温での耐オゾン性及び外観性に優れたタイヤが得られる。
【００１２】
【発明の実施の形態】
本発明に使用する炭化水素系ワックスは、炭素数３８〜５３の直鎖状飽和炭化水素と炭素数４２〜５１の分岐状飽和炭化水素との合計重量が該ワックス全体の５重量％以上１５重量％未満のもので、かつ炭素数２５〜４０の分岐状飽和炭化水素を２０〜３０重量％含有するものであり、その他の成分は特に制限されない。その他の成分としては、例えば、前記炭素数以外の直鎖状飽和（不飽和）炭化水素、分岐状飽和（不飽和）炭化水素、脂環族炭化水素、芳香族炭化水素などが挙げられる。また、本発明の効果を損なわない範囲で公知の添加剤を含有していてもよい。
【００１３】
前記炭化水素系ワックスの調製方法は特に制限されず、例えば、減圧蒸留法、溶剤脱油法、発汗法、プレス脱油法などの公知の方法を組み合わせることによりそれぞれの成分を濃縮したフラクションを得て、そのフラクションを前記配合比率になるように混合することにより調製することができる。炭化水素系ワックス中の炭素数３８〜５３の直鎖状飽和炭化水素及び炭素数４２〜５１の分岐状飽和炭化水素の重量、並びに炭素数２５〜４０の分岐状飽和炭化水素の重量はガスクロマトグラフなどにより測定することが可能である。
【００１４】
本発明の組成物ないしタイヤに使用するジエン系ゴム材料は特に制限されず、例えば、天然ゴム、スチレンブタジエンゴム、スチレンイソプレンゴム、ブタジエンゴム、イソプレンゴムなどが挙げられる。ゴム材料は、必要に応じて２種以上を混合して使用してもよい。
【００１５】
未加硫ゴム組成物には、通常ゴム工業界で用いられる各種添加剤を配合することができる。具体的にはカーボンブラック、シリカ等の補強充填剤、プロセスオイルないし可塑剤、酸化亜鉛、ステアリン酸、ステアリン酸亜鉛等の加工助剤、各種加硫促進剤、硫黄等の加硫剤、各種酸化防止剤などが例示される。シリカを補強充填剤として使用する場合にはＳｉ−６９（デグサ社）等のシランカップリング剤を添加することが好ましい態様である。
【００１６】
補強充填剤の添加量は、ゴム材料１００重量部に対して、カーボンブラックは０〜２００重量部、シリカは０〜１００重量部であり、カーボンブラックとシリカの合計添加量は、２０〜２００重量部であることが好ましい。
【００１７】
本発明の未加硫ゴム組成物は、公知の方法によって製造する。一般的には、加硫促進剤、硫黄等の加硫剤を除いた原材料をバンバリーミキサー等の混練装置を使用してマスターバッチを作製し、得られたマスターバッチを一旦冷却した後に混練ロールやバンバリーミキサー等の混練装置を使用して加硫剤、加硫促進剤を混合して未加硫ゴム組成物とする。
【００１８】
未加硫ゴム組成物の加硫は、従来と同様に加硫缶、加硫成形装置などを用いて、例えば１００〜２００℃の温度で行うことができるが、加硫温度は１４０〜１８０℃が好ましい。
【００１９】
得られる加硫ゴムは、シート状、板状、ロッド状、その他の形状の成形体として製造することができ、トレッド部、サイドウォール部、又はビード部等の構成材料として使用することができる。
【００２０】
【実施例】
以下、本発明の構成と効果を具体的に示す実施例等について説明する。
【００２１】
実施例及び比較例
ゴム配合は、天然ゴム（ＮＲ）５０重量部、ブタジエンゴム（ＢＲ）５０重量部、カーボンブラック（ＨＡＦ）６０重量部、亜鉛華３重量部、ステアリン酸２重量部を共通組成とし、表１に示した炭化水素系ワックス３重量部をそれぞれ添加してバンバリーミキサーにて混練してマスターバッチを作製した。マスターバッチを冷却した後、ゴム材料１００重量部に対して、硫黄２重量部、加硫促進剤（川口化学工業、アクセルＮＳ）１重量部を混練ロールを使用してそれぞれ混練し、未加硫ゴム組成物を得た。得られた未加硫ゴム組成物は、所定の金型を使用して１５０℃にて３０分加熱、加硫し、加硫ゴムとした。作製した加硫ゴムは、タイヤの加硫ゴムの評価方法に準じて評価した。
使用した炭化水素系ワックスの内容は、以下の通りである。なお、炭化水素系ワックス中の炭素数３８〜５３の直鎖状飽和炭化水素と炭素数４２〜５１の分岐状飽和炭化水素との合計重量％をＸ（重量％）とし、炭化水素系ワックス中の炭素数２５〜４０の分岐状飽和炭化水素の重量％をＹ（重量％）とする。
・ワックスＡ（Ｘ＝５重量％、Ｙ＝２０重量％）
・ワックスＢ（Ｘ＝１４重量％、Ｙ＝３０重量％）
・ワックスＣ（Ｘ＝２重量％、Ｙ＝２５重量％）
・ワックスＤ（Ｘ＝２０重量％、Ｙ＝２５重量％）
・ワックスＥ（Ｘ＝１０重量％、Ｙ＝１５重量％）
・ワックスＦ（Ｘ＝１０重量％、Ｙ＝３５重量％）
（評価）
＜加硫ゴムの外観性＞
作製した加硫ゴム片を４０℃に温度調節したギアーオーブン中に入れて３週間放置した。その後、加硫ゴム片の表面を目視により観察して下記の基準で外観性を評価した。
○：表面が黒く、ほとんど変色なし
△：やや白色又は茶色に変色している
×：白色又は茶褐色に変色している
＜加硫ゴムの耐オゾン性＞
作製した加硫ゴム片を２５％伸張した条件下でオゾンウェザーメータ装置中に設置し、オゾン濃度１００ｐｐｈｍ、温度５０℃の環境下で２４時間放置し、その後、クラックの発生状態を目視により観察し、下記の基準で耐オゾン性を評価した。
○：クラックの発生なし
△：１ｍｍ以下のクラックが発生している
×：１ｍｍを超えるクラックが発生している
【表１】

表１の結果から、本発明の未加硫ゴム組成物を加硫して得られる加硫ゴムは外観性及び耐オゾン性に優れたものであることがわかる（実施例１〜４）。
これに対して、本発明の炭化水素系ワックスを用いない場合（比較例１〜４）、及び本発明の炭化水素系ワックスを特定量用いない場合（比較例５、６）には、加硫ゴムの外観性又は耐オゾン性のいずれかが劣ることがわかる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an unvulcanized rubber composition for a tire and a tire obtained by vulcanizing and molding using at least a part of the rubber composition. More specifically, the present invention relates to a tire excellent in ozone resistance at high temperatures and excellent in appearance even when stored for a long time under high temperature conditions, and an unvulcanized rubber composition for a tire used in the tire. .
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a tire made of natural rubber or synthetic rubber has been used with a wax-based rubber antioxidant to prevent cracking of the rubber due to ozone in the atmosphere or ultraviolet rays in sunlight, that is, to prevent ozone deterioration. However, when such an antioxidant is used, there has been a problem that a bloom phenomenon occurs on the rubber surface and the antioxidant oozes out on the surface, whereby the tire is whitened and its appearance is deteriorated.
[0003]
Many techniques have been proposed to suppress such a bloom phenomenon. For example, a rubber composition obtained by blending 0.1 to 10 parts by weight of a hydrocarbon wax with respect to 100 parts by weight of natural rubber or diene-based synthetic rubber, wherein the component composition of the hydrocarbon wax has a carbon number of The ratio of the non-linear component having 29 to 39 to the linear component having 28 to 36 carbon atoms is 20 to 55% by weight, the total amount of the components is 30 to 65% by weight, and The total amount of the linear and non-linear components is 7 to 30% by weight, and the total amount of the linear components having 38 to 53 carbon atoms and the non-linear components having 42 to 51 carbon atoms is 15 to 35% by weight. And a rubber composition in which the total amount of a linear component having 32 to 46 carbon atoms and a non-linear component having 38 to 46 carbon atoms is 60% by weight or less, and air using the rubber composition in a skin member Japanese Patent Application Laid-Open No. H11-157,086 discloses a tire with a tire.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. H11-246706 [Problems to be Solved by the Invention]
However, the hydrocarbon wax described in Patent Literature 1 does not have sufficient ozone resistance at high temperatures, and the tire surface becomes white when a tire containing the wax is stored under high temperature conditions for a long period of time. Phenomenon (bloom phenomenon) cannot be effectively suppressed, which causes a problem in the appearance of the tire.
[0005]
An object of the present invention is to provide a tire having excellent ozone resistance at a high temperature and excellent appearance without causing a bloom phenomenon (whitening) even when stored under a high temperature condition, and used for the tire. An object of the present invention is to provide an unvulcanized rubber composition for a tire.
[0006]
[Means for Solving the Problems]
The present inventor has conducted intensive studies on unvulcanized rubber compositions for tires in order to achieve the above object, and found that the above object was achieved by using a hydrocarbon wax containing a specific amount of a saturated hydrocarbon having a specific carbon number. They have found that they can achieve this and have completed the present invention.
[0007]
That is, the unvulcanized rubber composition for a tire of the present invention contains 0.5 to 8 parts by weight of a hydrocarbon wax based on 100 parts by weight of a diene rubber material, and has 38 carbon atoms in the hydrocarbon wax. A total of 5 to less than 15% by weight of the total hydrocarbon wax, and a total weight of linear saturated hydrocarbons having a carbon number of from 53 to 53 and branched saturated hydrocarbons having a carbon number of from 42 to 51; Contains 20 to 30% by weight of a branched saturated hydrocarbon having 25 to 40 carbon atoms.
[0008]
When the amount of the hydrocarbon wax is less than 0.5 parts by weight, the ozone resistance at high temperatures is inferior. On the other hand, when the amount is more than 8 parts by weight, blooming occurs under high temperature conditions, and the appearance of the tire is reduced. Decreases. In order to further improve both performances, the amount of the hydrocarbon wax to be added is preferably 1 to 5 parts by weight.
[0009]
When the total weight of the linear saturated hydrocarbon having 38 to 53 carbon atoms and the branched saturated hydrocarbon having 42 to 51 carbon atoms in the hydrocarbon wax is less than 5% by weight of the whole wax, high temperature When the ozone resistance is insufficient, on the other hand, when it is 15% by weight or more, whitening of the tire surface occurs at a high temperature, and the appearance is reduced. The total weight of the linear saturated hydrocarbon having 38 to 53 carbon atoms and the branched saturated hydrocarbon having 42 to 51 carbon atoms in the hydrocarbon wax is preferably 7 to 14% by weight of the whole wax.
[0010]
Further, when the content of the branched saturated hydrocarbon having 25 to 40 carbon atoms in the hydrocarbon wax is less than 20% by weight, whitening of the tire surface occurs and appearance is reduced. On the other hand, if it exceeds 30% by weight, the ozone resistance at high temperatures becomes insufficient. The hydrocarbon wax preferably contains 20 to 25% by weight of a branched saturated hydrocarbon having 25 to 40 carbon atoms.
[0011]
The tire of the present invention is characterized in that it is obtained by vulcanizing and molding using at least a part of the unvulcanized rubber composition for a tire. Such a tire has better ozone resistance and appearance than ever before. In particular, a tire excellent in ozone resistance and appearance at high temperatures can be obtained by using it as a constituent material of a tread portion, a sidewall portion, a bead portion, etc., which are portions generating a large amount of heat.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
The hydrocarbon-based wax used in the present invention is such that the total weight of the linear saturated hydrocarbon having 38 to 53 carbon atoms and the branched saturated hydrocarbon having 42 to 51 carbon atoms is 5% by weight or more and 15% by weight of the whole wax. %, And contains 20 to 30% by weight of a branched saturated hydrocarbon having 25 to 40 carbon atoms, and other components are not particularly limited. Other components include, for example, linear saturated (unsaturated) hydrocarbons other than the above-mentioned carbon number, branched saturated (unsaturated) hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons and the like. Further, a known additive may be contained as long as the effects of the present invention are not impaired.
[0013]
The method for preparing the hydrocarbon wax is not particularly limited, and for example, fractions obtained by concentrating the respective components by combining known methods such as a vacuum distillation method, a solvent deoiling method, a perspiration method, and a press deoiling method are obtained. Then, it can be prepared by mixing the fractions so as to have the above-mentioned mixing ratio. The weight of the linear saturated hydrocarbon having 38 to 53 carbon atoms and the branched saturated hydrocarbon having 42 to 51 carbon atoms, and the weight of the branched saturated hydrocarbon having 25 to 40 carbon atoms in the hydrocarbon wax are determined by gas chromatography. It is possible to measure by such as.
[0014]
The diene rubber material used in the composition or tire of the present invention is not particularly limited, and examples thereof include natural rubber, styrene butadiene rubber, styrene isoprene rubber, butadiene rubber, and isoprene rubber. Two or more rubber materials may be used as a mixture, if necessary.
[0015]
Various additives usually used in the rubber industry can be blended in the unvulcanized rubber composition. Specifically, reinforcing fillers such as carbon black and silica, process oils or plasticizers, processing aids such as zinc oxide, stearic acid, zinc stearate, various vulcanization accelerators, vulcanizing agents such as sulfur, and various oxidizing agents Examples include an inhibitor. When silica is used as the reinforcing filler, it is a preferred embodiment to add a silane coupling agent such as Si-69 (Degussa).
[0016]
The reinforcing filler is added in an amount of 0 to 200 parts by weight for carbon black and 0 to 100 parts by weight for 100 parts by weight of the rubber material, and the total added amount of carbon black and silica is 20 to 200 parts by weight. Part.
[0017]
The unvulcanized rubber composition of the present invention is produced by a known method. In general, a vulcanization accelerator, a raw material excluding a vulcanizing agent such as sulfur is used to prepare a masterbatch using a kneading device such as a Banbury mixer, and after the obtained masterbatch is once cooled, a kneading roll or Using a kneading device such as a Banbury mixer, a vulcanizing agent and a vulcanization accelerator are mixed to obtain an unvulcanized rubber composition.
[0018]
The vulcanization of the unvulcanized rubber composition can be carried out at a temperature of, for example, 100 to 200 ° C. using a vulcanization can, a vulcanization molding device, or the like, as in the related art, but the vulcanization temperature is 140 to 180 ° C. Is preferred.
[0019]
The obtained vulcanized rubber can be manufactured as a molded article having a sheet shape, a plate shape, a rod shape, or another shape, and can be used as a constituent material of a tread portion, a sidewall portion, a bead portion, or the like.
[0020]
【Example】
Hereinafter, examples and the like that specifically show the configuration and effects of the present invention will be described.
[0021]
The rubber composition of the Examples and Comparative Examples has a common composition of 50 parts by weight of natural rubber (NR), 50 parts by weight of butadiene rubber (BR), 60 parts by weight of carbon black (HAF), 3 parts by weight of zinc white, and 2 parts by weight of stearic acid. Then, 3 parts by weight of the hydrocarbon wax shown in Table 1 were added to each, and kneaded with a Banbury mixer to prepare a master batch. After cooling the master batch, 2 parts by weight of sulfur and 1 part by weight of a vulcanization accelerator (Kawaguchi Chemical Industries, Axel NS) are kneaded using a kneading roll with respect to 100 parts by weight of the rubber material, respectively. A rubber composition was obtained. The obtained unvulcanized rubber composition was heated and vulcanized at 150 ° C. for 30 minutes using a predetermined mold to obtain a vulcanized rubber. The produced vulcanized rubber was evaluated according to the method for evaluating the vulcanized rubber of a tire.
The contents of the hydrocarbon wax used are as follows. The total weight% of the linear saturated hydrocarbon having 38 to 53 carbon atoms and the branched saturated hydrocarbon having 42 to 51 carbon atoms in the hydrocarbon wax is represented by X (% by weight), and Of the branched saturated hydrocarbon having 25 to 40 carbon atoms is represented by Y (% by weight).
Wax A (X = 5% by weight, Y = 20% by weight)
・ Wax B (X = 14% by weight, Y = 30% by weight)
・ Wax C (X = 2% by weight, Y = 25% by weight)
・ Wax D (X = 20% by weight, Y = 25% by weight)
Wax E (X = 10% by weight, Y = 15% by weight)
Wax F (X = 10% by weight, Y = 35% by weight)
(Evaluation)
<Appearance of vulcanized rubber>
The prepared vulcanized rubber pieces were placed in a gear oven controlled at a temperature of 40 ° C. and left for 3 weeks. Thereafter, the surface of the vulcanized rubber piece was visually observed, and the appearance was evaluated according to the following criteria.
：: Black surface, almost no discoloration △: Discolored slightly white or brown ×: Discolored white or brown <ozone resistance of vulcanized rubber>
The produced vulcanized rubber piece was placed in an ozone weather meter device under the condition of 25% elongation, left for 24 hours in an environment of an ozone concentration of 100 pphm and a temperature of 50 ° C., and thereafter, the state of occurrence of cracks was visually observed. The ozone resistance was evaluated according to the following criteria.
：: No cracks generated △: Cracks of 1 mm or less are generated x: Cracks of more than 1 mm are generated [Table 1]

From the results in Table 1, it can be seen that the vulcanized rubber obtained by vulcanizing the unvulcanized rubber composition of the present invention has excellent appearance and ozone resistance (Examples 1 to 4).
On the other hand, when the hydrocarbon wax of the present invention is not used (Comparative Examples 1 to 4) and when the specific amount of the hydrocarbon wax of the present invention is not used (Comparative Examples 5 and 6), vulcanization is performed. It can be seen that either the appearance of the rubber or the ozone resistance is inferior.

Claims

0.5 to 8 parts by weight of a hydrocarbon wax is contained based on 100 parts by weight of a diene rubber material, and a linear saturated hydrocarbon having 38 to 53 carbon atoms and 42 to 51 carbon atoms in the hydrocarbon wax. Is 5% by weight or more and less than 15% by weight based on the total weight of the hydrocarbon wax, and the hydrocarbon wax contains 20 to 40 branched saturated hydrocarbons having 25 to 40 carbon atoms. An unvulcanized rubber composition for a tire, comprising 30% by weight.

A tire obtained by vulcanizing and molding using the unvulcanized rubber composition for a tire according to claim 1 for at least a part thereof.