JP3794503B2 - Precure tread for studless tires - Google Patents

Description

【００１５】
上記表１は、本発明実施例３つと、比較例及び従来例を採用した各テストタイヤ（タイヤサイズ：１０．００ Ｒ２０ １４ＰＲ）を、一般貨物車両に装着して実車走行（未降雪路線走行）テストした結果を示している。
表１から明らかなように、本発明実施例１〜３は、従来例と比較して糊塗布面の粘着力及び成形加工性において全く遜色はないが、耐氷雪性能が大幅に向上している。
【００１６】
従来例は、天然ゴム、合成ゴム及びカーボンの混合物により成形されて一層のプレキュアトレッドであり実車走行距離は長く耐磨耗性はよいが耐氷雪性能は不適である。
そこで、従来例のトレッド部にナイロン樹脂の粒子を配合し耐氷雪性能は向上したが、粘着力が劣り成形加工性が悪いものであった（比較例）。
【００１７】
実施例１は比較例に比べ耐氷雪性能、成形加工性も向上し、スタッドレス用プレキュアトレッドに適するものである。
実施例２及び３はキャップゴム層の厚さを薄くしたもので耐磨耗性能を向上させることが出来た（実車走行距離指数の数値が上がっていく）。
なお、本発明は前記実施例に限定されるものではなく、種々変形することができる。例えば、トレッド１はキャップゴム層２とベースゴム層３とを、１つの金型内に２材料を挿入して一体になるように成形されているが、両ゴム層２、３を別個に成形し、両ゴム層２、３を接着した後に台タイヤに接着したり、ベースゴム層３を台タイヤに接着した後にキャップゴム層２を接着したりすることができる。
【００１８】
【発明の効果】
本発明は、上述のように、台タイヤ上に接着剤にて接合し次いで加圧加熱下で台タイヤに一体化成形される予め成形されたスタッドレスタイヤ用プレキュアトレッドであって、接地面側のキャップゴム層と反接地面側のベースゴム層の二層構造としたことを特徴とするものであるから、耐氷雪性能、耐摩耗性能、成形加工性及び更正タイヤの品質の向上を図ることができる。
【図面の簡単な説明】
【図１】 本発明の実施例の要部を示す断面図である。
【図２】 第２実施例の要部を示す断面図である。
【図３】 従来の更正用トレッドを用いた更正タイヤの断面図である。
【図４】 従来例の要部拡大断面図である。
【符号の説明】
１ プレキュアトレッド
２ キャップゴム層
３ ベースゴム層[0001]
[Industrial application fields]
The present invention relates to a pre-cured tread for a studless tire which is used for correcting a tire whose tread portion is worn by use.
[0002]
[Prior art]
Conventionally, as illustrated in FIG. 3, a new tread 12 molded in advance is bonded onto the base tire 11 from which the tread that has been worn away by use is removed by buffing the bonding surface 13 with an unvulcanized cushion rubber and an adhesive. Thereafter, there is a corrected tire 10 integrated with the base tire 11 under pressure and heating.
[0003]
As shown in FIG. 4, the tread 12 has a single layer rubber layer and is formed of a mixture of natural rubber, synthetic rubber (BR, SBR) and carbon.
[0004]
[Problems to be solved by the invention]
By the way, the conventional example has a problem in ice / snow resistance. Therefore, as a constituent material of tread, in addition to natural rubber, synthetic rubber (BR, SBR), carbon, foaming agent or inorganic / organic substance particles are blended to improve the frictional force on the road surface on ice, and performance on ice. It is conceivable to improve the performance on snow (see the comparative example in Table 1).
[0005]
However, when organic / inorganic particles are mixed with the tread constituent material, when the bonding surface is buffed, the particles appear on the surface, resulting in minute irregularities and a decrease in the bonding surface area, and the lack of the particles. A cavity is formed, and glue enters the cavity and penetrates to reduce adhesive strength (especially aging). In addition, molding processability is significantly reduced, and in some cases, air remains on the bonding surface, resulting in poor adhesion. There are problems such as poor wear resistance.
[0006]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a pre-cured tread for a studless tire that can improve ice / snow resistance, wear resistance, and moldability. In offer.
[0007]
[Means for Solving the Problems]
In the present invention, in order to achieve the above object, the following technical means are taken.
That is, the present invention, natural rubber (50 to 70 parts by weight) cap rubber layer is tangent ground side, synthetic rubber (BR30～50 parts by weight), carbon (40 to 60 parts by weight), inorganic or organic substance particles ( is formed by a mixture of 2 to 15 parts by weight), Igo base rubber layer joined to the counter-contact surface side base tire is such not mixed with particles of an inorganic or organic substance synthetic rubber (BR20～40 parts by weight), synthetic Formed with a mixture of rubber (60 to 80 parts by weight of rubber) and carbon (35 to 55 parts by weight), the cap rubber layer and the base rubber layer are formed as a two-layer structure, and the surface of the base rubber layer on the base tire side There are buffed, you are characterized by being formed to a depth that the major groove of the ground surface reaches the base rubber layer from the cap rubber layer.
[0008]
[Action]
According to the present invention, even when the anti-ground surface side adhesive surface is buffed, it is a base rubber layer that is not fluffed, so that the adhesive surface, i.e., the buffed surface, becomes smooth without any fuzzing or unevenness. Since it does not permeate even if it is applied, adhesion is improved, no poor bonding occurs, molding workability is remarkably improved, and wear resistance can be improved. Further, by using a constituent material that can improve the ice / snow resistance with the grounding side as a cap rubber layer, the ice / snow resistance can be greatly improved and the durability can be ensured.
[0009]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows an embodiment of a tread 1 according to the present invention, which is pre-cured (unvulcanized), and has a cap rubber layer 2 on the ground surface side and a base rubber layer 3 on the anti-ground surface side. A plurality of main grooves 4 are provided in the circumferential direction on the grounding surface side, and the anti-grounding surface is an adhesive surface 3A to be joined to the base tire from which the tread is removed. Is buffed.
[0010]
The material constituting the cap rubber layer 2 is excellent in ice and snow resistance, natural rubber (50 to 70 parts by weight), synthetic rubber (BR) (30 to 50 parts by weight), carbon (40 to 60 parts by weight). Part), particles of inorganic and organic substances, sand, steel, short fibers, etc. (2 to 15 parts by weight) are mixed. Further, the material constituting the base rubber layer 3 has excellent wear resistance, such as synthetic rubber (BR) (20 to 40 parts by weight), synthetic rubber (SBR) (60 to 80 parts by weight), carbon (35 to 55 parts by weight) is mixed.
[0011]
The cap rubber layer 2 is mixed with the particles in order to ensure ice / snow resistance. In order to prevent hardening at low temperatures, natural rubber and BR are mainly used, and a softening agent is used.
In addition, since the particles are not mixed in the base rubber layer 3, there are no minute irregularities and cavities (pores), the surface is smooth, and even if the bonding surface to the base tire is buffed, Since there is no fluffing or cavitation, the bonding area does not decrease, and even if an adhesive is applied, it does not penetrate so that sufficient adhesion is ensured, and there is no adhesion failure, and a good quality tread is obtained. And moldability is improved.
[0012]
The thickness TC of the cap rubber layer 2 and the thickness TB of the base rubber layer 3 vary depending on the tread size, but can be variously selected.
As shown in the embodiment of FIG. 1, the rubber layer composition ratio when emphasizing general or wear resistance is 50 to 60% of the depth D of the main groove 4 that guarantees ice and snow resistance performance. It is preferable to set the thickness TC of the base rubber layer 3 to the thickness TB.
[0013]
In addition, when emphasizing ice and snow resistance, as shown in the second embodiment of FIG. 2, the dimension TD from the bottom of the main groove 4 to the layer boundary surface is small, for example, the dimension TD is close to 1.7 mm. It is preferable to make the thickness TC of the cap rubber layer 2 as large as possible, or so that the cap rubber thickness TC is about 90% of the depth D of the main groove 4.
[0014]
[Table 1]

[0015]
The above Table 1 shows that the test tires (tire size: 10.00 R20 14PR) adopting three examples of the present invention, the comparative example and the conventional example are mounted on a general freight vehicle and traveled on an actual vehicle (running on a snowy route). The test results are shown.
As is clear from Table 1, Examples 1 to 3 of the present invention are not inferior in the adhesive force and molding processability of the glue application surface as compared with the conventional example, but the ice and snow resistance performance is greatly improved. .
[0016]
The conventional example is a single precure tread molded from a mixture of natural rubber, synthetic rubber and carbon, and has a long mileage and good wear resistance, but is not suitable for ice and snow resistance.
Therefore, nylon resin particles were blended in the tread portion of the conventional example to improve the ice / snow resistance, but the adhesive strength was poor and the moldability was poor (Comparative Example).
[0017]
Example 1 has improved ice / snow resistance and molding processability compared to the comparative example, and is suitable for a studless precure tread.
In Examples 2 and 3, the thickness of the cap rubber layer was reduced, and the wear resistance performance could be improved (the actual vehicle mileage index increased).
In addition, this invention is not limited to the said Example, A various deformation | transformation can be carried out. For example, the tread 1 is formed such that the cap rubber layer 2 and the base rubber layer 3 are integrated by inserting two materials into one mold, but the rubber layers 2 and 3 are separately formed. Then, the rubber layers 2 and 3 can be bonded together and then bonded to the base tire, or the base rubber layer 3 can be bonded to the base tire and the cap rubber layer 2 can be bonded.
[0018]
【The invention's effect】
The present invention, as described above, is a pre-cured treadless tire pre-cured tread that is bonded to a base tire with an adhesive and then integrally molded with the base tire under pressure and heating. The cap rubber layer and the base rubber layer on the anti-ground surface side have a two-layer structure, which improves ice / snow resistance, wear resistance, molding processability, and the quality of the rectified tire. Can do.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a main part of an embodiment of the present invention.
FIG. 2 is a cross-sectional view showing a main part of a second embodiment.
FIG. 3 is a cross-sectional view of a correction tire using a conventional correction tread.
FIG. 4 is an enlarged cross-sectional view of a main part of a conventional example.
[Explanation of symbols]
1 Precure tread 2 Cap rubber layer 3 Base rubber layer

Claims (1)

Contacting the ground side of the cap rubber layer of natural rubber (50 to 70 parts by weight), synthetic rubber (BR30～50 parts by weight), carbon (40 to 60 parts by weight), inorganic or organic substance of the particles (2 to 15 parts by weight) is formed with a mixture of Igo base rubber layer joined to the counter-contact surface side base tire is such not mixed with particles of an inorganic or organic substance synthetic rubber (BR20～40 parts by weight), synthetic rubber (SBR60～80 weight parts) and formed by a mixture of carbon (35 to 55 parts by weight), the cap rubber layer and a base rubber layer is formed as a two-layer structure, the base tire side surface of the base rubber layer are buffed , precured tread for a studless tire characterized by being formed to a depth that the major groove of the ground surface reaches the base rubber layer from the cap rubber layer.

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