JP2004051811A

JP2004051811A - Pneumatic tire

Info

Publication number: JP2004051811A
Application number: JP2002212069A
Authority: JP
Inventors: Masanori Aoyama; 青山　正憲
Original assignee: Bridgestone Corp
Current assignee: Bridgestone Corp
Priority date: 2002-07-22
Filing date: 2002-07-22
Publication date: 2004-02-19
Anticipated expiration: 2022-07-22
Also published as: JP4107900B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pneumatic tire which prevents bacteria from adhering thereto and diffusing by imparting antibacterial properties to a tire sheath member without detriment to abrasion resistance and fracture resistance as inherent performances of the tire. <P>SOLUTION: The pneumatic tire is obtained by applying a rubber composition comprising an antibacterial agent to at least a sheath member of the tire. The amount of the antibacterial agent is preferably 0.1-5.0 pts. mass based on 100 pts. mass of a rubber component comprising natural rubber and/or a synthetic diene rubber. The antibacterial agent is preferably an inorganic antibacterial agent and more preferably a silver-containing antibacterial agent. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、空気入りタイヤに関し、特に抗菌性が要求されるあらゆるタイプの空気入りタイヤに関する。
【０００２】
【従来の技術】
近年の交通機関の発達、特に航空機や高速道路網の発達により、高速での国境間及び大陸間の移動が可能になり、利便性の向上につながっている。一方で、かかる交通手段、例えば航空機やトラック・バス・乗用車等に用いるタイヤへの細菌類の付着による拡散が、今後無視できない問題となるおそれがある。
【０００３】
また、身近な例として、畑や水田で使用する農業機械や荒地等で使用する建設用車両では、土や泥中に含まれる病原菌を拡散させない目的で、付着した土や泥をタイヤや機械から落とすのは勿論、殺菌することまでもが推奨されている。
【０００４】
【発明が解決しようとする課題】
本発明の目的は、タイヤ本来の性能である耐摩耗性及び耐破壊性を損なうことなく、タイヤ外皮部材に抗菌性をもたせて、細菌類がタイヤに付着し拡散するのを防止した空気入りタイヤを提供することにある。
【０００５】
【課題を解決するための手段】
本発明者は、上記目的を達成するために鋭意検討した結果、タイヤの少なくとも外皮部材、特にトレッドゴム及びサイドゴムに抗菌剤を含ませることにより、細菌類のタイヤへの付着・拡散を防止できることを見出し、本発明を完成させるに至った。
【０００６】
即ち、本発明は、抗菌剤を配合してなるゴム組成物を、タイヤの少なくとも外皮部材に用いることを特徴とする空気入りタイヤである。
【０００７】
本発明の空気入りタイヤの好適例においては、前記抗菌剤は、天然ゴム及び／又はジエン系合成ゴムからなるゴム成分１００質量部に対し０．１〜５．０質量部である。
【０００８】
本発明の空気入りタイヤの他の好適例においては、上記抗菌剤は無機系抗菌剤であり、銀系抗菌剤であるのがより好ましい。
【０００９】
【発明の実施の形態】
以下に、本発明を詳細に説明する。本発明の空気入りタイヤは、航空機用タイヤ、トラック・バス用タイヤ、乗用車用タイヤ、農業機械用タイヤ、建設車両用タイヤ等で、その構造は現用のものと同じであるが、該タイヤの少なくとも外皮部材、特にトレッドゴム及びサイドゴムが抗菌剤を配合してなるゴム組成物で構成されている。このため、タイヤ外皮部材への細菌類の付着が抑制される。
【００１０】
本発明に用いる抗菌剤は、通常使用されている抗菌剤である。該抗菌剤としては、有機系、無機系の抗菌剤がある。無機系抗菌剤としては、銀、銅、亜鉛等の抗菌性金属イオンを担持させた無機化合物であれば特に制限はない。該抗菌性金属イオンを担持させる無機化合物としては、活性炭等の無機吸着剤、ハイドロキシアパタイト等の無機イオン交換体がある。有機系抗菌剤としては、ニトリル誘導体、イミダゾール誘導体、フェノールエーテル誘導体等が挙げられる。この中でも、タイヤの製造条件の一つである加硫温度でリキャップを繰り返す航空機用タイヤ及び２０年近くもの長期間に渡って使用される農業機械用タイヤを考慮すると、長期に渡って抗菌作用を発揮する無機系抗菌剤が好ましく、銀系抗菌剤がより好ましい。銀系抗菌剤としては、銀化合物、銀化合物及び／又は銀錯塩を担持させた多孔性構造体、多孔性構造体に銀イオンをイオン交換させたもの等が挙げられる。銀化合物としては、例えばコロイダル状の銀、炭酸銀、塩素酸銀、過塩素酸銀、臭素酸銀、塩化銀、酢酸銀、チオサルファイト銀錯体等が挙げられる。
【００１１】
抗菌剤の使用量は、ゴム成分１００質量部に対して、０．１〜５．０質量部が好ましい。０．１質量部未満では、抗菌性が充分でなく、５．０質量部を超えると、タイヤ外皮部材本来の性能である耐摩耗性及び耐破壊性が低下する。
【００１２】
本発明のタイヤの外皮部材に用いるゴム組成物を構成するゴム成分は、天然ゴム及び／又はブタジエンゴム等のジエン系合成ゴムである。また、該ゴム組成物には、上述の抗菌剤及びゴム成分の他、外皮部材に通常用いられるカーボンブラック、老化防止剤、ワックス、硫黄、加硫促進剤等の配合剤を適宜配合することができる。
【００１３】
なお、本発明の空気入りタイヤに充填する気体としては、通常の或いは酸素分圧を調整した空気の他、窒素、アルゴン、ヘリウム等の不活性ガスを用いることができる。
【００１４】
【実施例】
以下に、実施例及び比較例を挙げて本発明を更に詳しく説明するが、本発明はこれらの例に限定されるものではない。
【００１５】
タイヤの外皮部材用のゴム組成物を表１に記載の配合処方に従って調製し、所定温度時間で加硫してゴム試験片を作製し、その耐破壊性、耐摩耗性及び抗菌性を下記の方法により測定した。
【００１６】
（１）耐破壊性
ＪＩＳ　Ｋ　６２５０伸張試験により破断時の引張り強さを測定し、比較例１を１００として指数表示した。結果を表１に示す。数値が大きい程、耐破壊性が良好であることを示す。
【００１７】
（２）耐摩耗性
ランボーン式摩耗試験によりゴムの摩耗減量を測定し、比較例１を１００として指数表示した。結果を表１に示す。数値が大きい程、耐摩耗性が良好であることを示す。
【００１８】
（３）抗菌性
被検菌として大腸菌を用い、菌液０．２ｍＬを３×３ｃｍの上記ゴム試験片のシートの表面に菌数が３×１０^５個となるよう一様に塗布し、ポリエチレンフィルムでラップして、２７℃で保存した。保存開始から０時間後、２４時間後に、シート上の生き残り菌を菌数測定用培地に洗い出し、希釈平板培養法（３７℃、２日間）により培養した後、生菌数を測定し、３×３ｃｍのシート当りの生菌数に換算した。結果を表１に示す。表中、×は生菌数が５×１０^４以上であることを、△は生菌数が５×１０^２以上且つ５×１０^４未満であることを、○は生菌数が５×１０^２未満であることを示す。
【００１９】
【表１】

【００２０】
実施例１〜４の配合のゴムは２４時間後の生菌数が５×１０^２未満であり、高い抗菌性を有していた。
【００２１】
比較例２の配合のゴムは、抗菌剤の配合量が本発明で規定する範囲より少ないため、抗菌性が不充分であった。また、比較例３の配合のゴムは、高い抗菌性を有するものの、抗菌剤の配合量が本発明で規定する範囲より多いため、耐破壊性及び耐摩耗性が低下した。
【００２２】
【発明の効果】
本発明によれば、タイヤ本来の性能である耐摩耗性及び耐破壊性を損なうことなく、タイヤの外皮部材に抗菌性をもたせて、細菌類がタイヤに付着拡散するのを防止することができる。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pneumatic tire, and more particularly, to any type of pneumatic tire requiring antibacterial properties.
[0002]
[Prior art]
2. Description of the Related Art The recent development of transportation systems, particularly the development of aircraft and a highway network, has made it possible to move between borders and continents at high speed, leading to improved convenience. On the other hand, diffusion due to the adhesion of bacteria to tires used in such transportation means, for example, aircraft, trucks, buses, passenger cars, and the like, may become a problem that cannot be ignored in the future.
[0003]
Also, as a familiar example, in agricultural machines used in fields and paddy fields and construction vehicles used in rough terrain, attached soil and mud are removed from tires and machinery in order to prevent the spread of pathogens contained in soil and mud. It is recommended not only to remove, but also to sterilize.
[0004]
[Problems to be solved by the invention]
An object of the present invention is to provide a tire outer member with antibacterial properties without impairing the tire's original performance of abrasion resistance and destruction resistance, thereby preventing bacteria from attaching and diffusing to the tire. Is to provide.
[0005]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to achieve the above object, and as a result, by including an antibacterial agent in at least the outer skin member of the tire, particularly the tread rubber and the side rubber, it is possible to prevent the adhesion and diffusion of bacteria to the tire. As a result, the present invention has been completed.
[0006]
That is, the present invention is a pneumatic tire characterized in that a rubber composition containing an antibacterial agent is used for at least an outer cover member of the tire.
[0007]
In a preferred example of the pneumatic tire of the present invention, the antibacterial agent is used in an amount of 0.1 to 5.0 parts by mass based on 100 parts by mass of a rubber component composed of a natural rubber and / or a diene-based synthetic rubber.
[0008]
In another preferred embodiment of the pneumatic tire of the present invention, the antibacterial agent is an inorganic antibacterial agent, and more preferably a silver antibacterial agent.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail. The pneumatic tire of the present invention is a tire for aircraft, a tire for trucks and buses, a tire for passenger cars, a tire for agricultural machinery, a tire for construction vehicles, and the like. The outer cover member, in particular, the tread rubber and the side rubber are made of a rubber composition containing an antibacterial agent. For this reason, adhesion of bacteria to the tire outer member is suppressed.
[0010]
The antibacterial agent used in the present invention is a commonly used antibacterial agent. Such antibacterial agents include organic and inorganic antibacterial agents. The inorganic antibacterial agent is not particularly limited as long as it is an inorganic compound carrying antibacterial metal ions such as silver, copper, and zinc. Examples of the inorganic compound supporting the antibacterial metal ion include an inorganic adsorbent such as activated carbon and an inorganic ion exchanger such as hydroxyapatite. Examples of the organic antibacterial agent include a nitrile derivative, an imidazole derivative, and a phenol ether derivative. Among them, aircraft tires that repeatedly recap at the vulcanization temperature, which is one of the tire manufacturing conditions, and agricultural machinery tires that are used for a long period of nearly 20 years are considered. An inorganic antibacterial agent which exerts its effect is preferable, and a silver antibacterial agent is more preferable. Examples of the silver-based antibacterial agent include a silver compound, a porous structure supporting a silver compound and / or a silver complex salt, and a porous structure obtained by ion-exchanging silver ions in the porous structure. Examples of the silver compound include colloidal silver, silver carbonate, silver chlorate, silver perchlorate, silver bromate, silver chloride, silver acetate, and silver thiosulfite complex.
[0011]
The amount of the antibacterial agent used is preferably 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the rubber component. When the amount is less than 0.1 part by mass, the antibacterial property is not sufficient, and when the amount exceeds 5.0 parts by mass, the wear resistance and the fracture resistance, which are inherent performances of the tire skin member, are reduced.
[0012]
The rubber component constituting the rubber composition used for the outer skin member of the tire of the present invention is a natural rubber and / or a diene-based synthetic rubber such as butadiene rubber. Further, in addition to the above-described antibacterial agent and rubber component, compounding agents such as carbon black, an antioxidant, wax, sulfur, and a vulcanization accelerator, which are usually used for the outer cover member, may be appropriately added to the rubber composition. it can.
[0013]
In addition, as a gas filled in the pneumatic tire of the present invention, an inert gas such as nitrogen, argon, helium, or the like can be used in addition to normal or air whose oxygen partial pressure is adjusted.
[0014]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
[0015]
A rubber composition for a tire skin member was prepared in accordance with the formulation shown in Table 1, and vulcanized at a predetermined temperature for a predetermined time to produce a rubber test piece. It was measured by the method.
[0016]
(1) Fracture resistance The tensile strength at break was measured by a JIS K 6250 elongation test, and the index was indicated as an index with Comparative Example 1 being 100. Table 1 shows the results. The larger the value, the better the fracture resistance.
[0017]
(2) Abrasion resistance Abrasion loss of rubber was measured by a Lambourn-type abrasion test, and Comparative Example 1 was set to 100 and indicated as an index. Table 1 shows the results. The larger the value, the better the wear resistance.
[0018]
(3) Escherichia coli was used as an antibacterial test bacterium, and 0.2 mL of the bacterial solution was uniformly applied to the surface of a 3 × 3 cm sheet of the rubber test piece so that the number of bacteria was 3 × 10 ⁵ , and polyethylene was applied. Wrapped with film and stored at 27 ° C. 0 hours and 24 hours after the start of storage, the surviving bacteria on the sheet are washed out in a medium for counting the number of bacteria, cultured by a dilution plate culture method (37 ° C., 2 days), and the number of viable bacteria is measured. It was converted to the number of viable bacteria per 3 cm sheet. Table 1 shows the results. In the table, × indicates that the viable cell count is 5 × 10 ⁴ or more, Δ indicates that the viable cell count is 5 × 10 ² or more and less than 5 × 10 ⁴ , and ○ indicates that the viable cell count is 5 × 10 4 Indicates less than ² .
[0019]
[Table 1]

[0020]
The rubbers of Examples 1 to 4 had a viable cell count of less than 5 × 10 ² after 24 hours and had high antibacterial properties.
[0021]
The rubber of Comparative Example 2 had insufficient antibacterial properties because the amount of the antibacterial agent was less than the range specified in the present invention. Further, although the rubber of the compound of Comparative Example 3 had high antibacterial properties, since the compounding amount of the antibacterial agent was larger than the range specified in the present invention, the fracture resistance and the abrasion resistance were reduced.
[0022]
【The invention's effect】
According to the present invention, it is possible to prevent bacteria from adhering and diffusing to the tire by imparting antibacterial properties to the outer skin member of the tire without impairing the abrasion resistance and the destruction resistance which are the original performances of the tire. .

Claims

A pneumatic tire characterized in that a rubber composition containing an antibacterial agent is used for at least an outer skin member of the tire.

The pneumatic tire according to claim 1, wherein the antibacterial agent is used in an amount of 0.1 to 5.0 parts by mass based on 100 parts by mass of a rubber component composed of natural rubber and / or a diene-based synthetic rubber.

The pneumatic tire according to claim 1, wherein the antibacterial agent is an inorganic antibacterial agent.

The pneumatic tire according to claim 3, wherein the inorganic antibacterial agent is a silver antibacterial agent.