JP3549062B2 - Pneumatic tire having color rubber for identification - Google Patents

Description

【００１９】
【表２】

【００２０】
耐光試験の結果は、実施例１〜９は表１に、実施例１０，１１及び各比較例は表２に示した。本発明の光安定剤であるヒンダートアミン系としてＨ１を配合した場合では、ゴム１００重量部に対して５．０ 重量部（実施例４）を配合した場合は、屋外暴露試験、紫外線暴露試験共に最高であり、またヒンダートアミン系であってもＨ２を配合した場合では、ベンゾントリアゾール系を併用した場合（実施例１１）が最高である。そして、ヒンダートアミン系のＨ１とベンゾントリアゾール系を併用した場合（実施例９）も最高値を示した。一方、ヒンダートアミン系以外の光安定剤では共に耐光性は改良されていない（各比較例参照）。従って、ヒンダートアミン系では、他の光安定剤との併用した配合系においても耐光性が優れている点が認められた。
【００２１】
【発明の効果】
この発明は、上述のとおり構成されているために、以下の効果を奏する。即ち、光安定剤としてヒンダートアミン系化合物を用いたので、紫外線吸収剤として作用する他の光安定剤に比してすぐれた光安定効果を発揮する。また、前記この発明の光安定剤は、ゴム分をベースとしたカラーゴム配合であるために、この配合にはカーボンブラックを除外するだけのゴム配合でよく、また該カラーゴムのゴムストリップは押出し加工等で成形されるので、タイヤ成形工程において該ゴムストリップを予めサイドウォール部ゴム面上の適所に載置貼着するだけでよく、しかも、カラーゴムのストリップはタイヤの加硫工程において加硫されてサイドウォール部面に加硫接着されるので剥離することなく、また道路の縁石等と接触しても反発弾性に富んでいるので破損に耐える。特に、従来の技術に見られたカラーゴムを貼着するサイドウォール部面に対してアミン系老化防止剤の排除の予備処理は必要なく、通常のタイヤ成形工程において、簡易かつ、任意の識別用カラーゴムの選択・応用が可能である。
【図面の簡単な説明】
【図１】この発明の一実施例を半断面にして示す部分斜視説明図である。
【符号の説明】
１ タイヤ
２ トレッド部
３ ビード部
３′ ビードコア
４ サイドウォール部
５ カーカス層
６ ベルト層
Ｃ カラーゴム細帯体[0001]
[Industrial applications]
The present invention relates to a pneumatic tire having a color rubber for identification, and more particularly to a pneumatic tire with improved light stability of a color rubber formed on a sidewall portion of the tire.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in order to identify and differentiate a tire owned by oneself from others, a mark is often made as a self-marking mark in an appropriate place on a tire sidewall portion. As a result, a branding having an uneven surface with a mark was pressed and formed on the sidewall portion. However, although this type of branding can identify the tire, the branding not only impairs the appearance of the tire sidewall portion, but also uses a branding iron with a stamp, so that the rubber on the sidewall portion is sometimes burnt. However, there is a defect that the tires are deteriorated by the high temperature and the original function of the tire cannot be sufficiently exhibited. The original purpose of using the branding for identification was to prevent theft of tires for which it owns its own rights, but for companies involved in the transportation and transportation of trucks, buses, taxis, etc., adding a corporate image in color is also added to this. Nowadays, there is a technical need to select specific company colors and marks for tires owned by the company and to easily and quickly apply these colors to tires.
[0003]
Heretofore, there have been various methods of forming a color rubber on a tire sidewall portion, but the method is somewhat complicated in a process and not very simple. For example, for a colored portion of a tire sidewall portion, a rubber composition containing a non-diene rubber from which an amine anti-aging agent that easily discolors due to ultraviolet rays is removed, and a coloring containing a non-diene rubber as a main component on its surface. A method of bonding rubber (JP-A-63-34207) has been attempted. Also, a method is provided in which a weather-resistant cover sheet is provided on the upper surface of a plurality of decorative portions of a tire sidewall portion and vulcanized, and thereafter the decorative portion is exposed by buffing the cover sheet (Japanese Patent Laid-Open No. 4-121205). Gazette) has also been attempted. Further, various methods such as a method of forming a concave groove in a side wall portion and attaching a sticker in the groove to prevent peeling (JP-A-6-40219) have been tried.
[0004]
[Problems to be solved by the invention]
However, in the above-mentioned conventional method, a non-diene rubber must be used for the color rubber, and migration contamination from the amine-based inhibitor must be prevented. The process is complicated because it requires additional work steps, such as removal by buffing later, and, on the other hand, a tire vulcanization mold is required to form a concave groove in the sidewall portion. In addition to the need for a specific vulcanizing mold to form a convex groove on the side wall, it can be easily achieved in terms of material and work process, such as sticking a sticker to the sidewall after vulcanization. Was not.
[0005]
Therefore, the present inventors do not need to be isolated from the amine-based anti-aging agent as in the prior art in order to cope with the above situation, and also need to form a concave groove in the side wall portion and further buff the carver sheet. First, in order to simplify the process that can be carried out as it is in the conventional tire molding and vulcanization process without requiring extra work man hours such as hanging, first, earnestly study the compounding system of color rubber. Subsequently, in particular, as a result of examining various light stabilizers which are not affected by the amine anti-aging agent in the compounding of the side wall rubber and have excellent stability to ultraviolet light, a certain kind of light stabilizer was obtained. It has now been found that light stabilizers meet this purpose. That is, an object of the present invention is to provide a pneumatic tire in which a light-stable color rubber having an arbitrary color is easily formed on an appropriate portion of a tire sidewall portion.
[0006]
[Means for Solving the Problems]
A feature of the present invention that meets the above-mentioned object is that a pneumatic pneumatic tire includes an annular tread portion, a pair of bead portions, and a sidewall portion extending from both ends of the tread portion to the bead portion. In the tire, a color rubber containing a hindered amine-based light stabilizer is formed as a color rubber compounding system containing no carbon black at an appropriate position on a sidewall portion.
[0007]
The color rubber compounding system in the present invention is based on a rubber component and mainly contains a coloring material such as an organic pigment, a light stabilizer, and various compounding agents for vulcanizing the rubber component. It is. It is necessary to exclude carbon black in this compounding system. The hindered amine-based light stabilizer used in the present invention is generally a hindered amine-based compound classified as an ultraviolet absorber or a stabilizer, and the functional group has a chemical structural steric hindrance. An amine compound having the property corresponds to this. The reason why the present invention is superior to other ultraviolet absorbers / stabilizers for the purpose of the present invention is that the hindered amine compound mainly functions as a light-stable antioxidant, Is effective for high polymers. In particular, this kind of hindered amine-based light stabilizer decomposes hydroperoxide, which is a photodegradation initiator of rubber, in a non-radical manner, and catalytically captures and removes harmful radicals accompanying the regeneration of stable N-oxyl. In addition to showing light resistance by performing, a transition metal such as titanium can provide light resistance by forming a kind of complex with the transition metal and inactivating it. Are particularly suitable for the color rubber compounding system of the present invention.
[0008]
Specific examples of the hindered amine light stabilizer include, for example, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate (hereinafter, this compound is abbreviated as “H1”), bis ( 1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- {3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -4- {3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy} -2,2,6,6-tetramethylpiperidine (hereinafter, this compound is abbreviated as "H2"), 8-benzyl -7,7,9,9-Tetramethyl-3-octyl-1,2,3-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy-2,2,6,6-tetra Methyl piperidine, this is Dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidyl polycondensate, poly [[6- (1,1,3,3-tetramethylbutyl) imino -1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [[2,2,6,6-tetramethyl-4 -Piperidyl) imino]], bis (1,2,2,6,6-pentamethyl-4-piperidyl) 2- (3,5-di-tert-butyl-4-hydroxybenzyl) -2-n-butylmalonate ), Tetraxy (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, 1,2,3,4-butanetetracarboxylic acid and 1,2,2 , 6,6-Pentamethyl-4-piperidi A condensate of 1,2,3,4-butanetetracarboxylic acid with 2,2,6,6-tetramethyl-4-piperidinol and tridecyl alcohol; 3,4-butanetetracarboxylic acid, 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9- (2,4,8,10 Condensation product with -tetraoxaspiro [5,5] undecane) diethanol, 1,2,3,4-butanetetracarboxylic acid, 2,2,6,6-tetramethyl-4-piperidinol and β, β, Condensation product with β ', β'-tetramethyl-3,9- (2,4,8,10-tetraoxaspiro [5,5] undecane) diethanol, 1,2,2,6,6-tetramethyl -4-piperidyl-methacrylate, and 2,2,6,6-tetramethyl-4-piperidyl - there is methacrylate.
[0009]
Suitable rubber components in the color rubber compounding system include, for example, natural rubber, polybutadiene rubber, polyisoprene rubber, styrene / butadiene copolymer rubber, halogenated butyl rubber, chloroprene rubber, ethylene / propylene terpolymer rubber, And a diene-based or non-diene-based rubber such as chlorosulfonated polyethene. Among them, natural rubber, polybutadiene rubber and chlorinated butyl rubber are particularly preferable. Here, it should be particularly noted that, in the present invention, since a color rubber compounding system is used, the addition of carbon black must be avoided in this system. On the other hand, various inorganic and organic pigments as coloring agents can be used depending on the purpose of the identification color.
[0010]
The position at which the color rubber in the present invention is formed on the tire side wall portion is mainly suitable near the bead portion, but is not particularly limited thereto. The shape of the color rubber is not particularly limited, but a narrow band, a tape, or the like is appropriate in the working process. If necessary, a notch of various shapes may be provided in the peripheral portion of the narrow band or the like, and further, if a through hole of a specific shape is provided in advance in the narrow band, a sidewall of the tire may be provided. A plurality of decorative patterns are revealed in contrast with the black color of the part. In the present invention, not only a simple band of color rubber is pasted, but also in relation to colors and patterns, characters, symbols, patterns, etc. are pre-engraved or colored on the surface based on the color rubber by coloring or pasting. You can, of course. The thickness of the color rubber is not particularly limited, but in the vulcanization step, in order to eliminate the pressure expansion of the peripheral portion due to the vulcanization pressure of the color rubber against the side wall portion surface, and to make both surfaces substantially flush, About 0.5 to 2 mm is preferable. Next, as a method of forming the color rubber on the tire side wall portion in the present invention, in a tire molding step, a strip of color rubber extruded in advance is placed and adhered to a predetermined position on the side wall rubber surface. If this is molded by a normal tire molding method and then vulcanized by a normal tire vulcanizing mold, the color rubber is also vulcanized at the same time and is vulcanized and adhered to a predetermined position on the side wall surface. Is strong, and the color rubber surface and the sidewall portion surface are substantially flush with each other, so that the tire does not peel and break even if it comes into contact with a curb or the like on a road while the tire is running.
[0011]
[Action]
In the compounding system of the color rubber for identification in the present invention, it is necessary that carbon black is not mixed in the compounding system, and the compounding system includes ordinary natural rubber such as natural rubber, polybutadiene rubber, and polyisoprene rubber. Since the synthetic rubber is used, the vulcanized color rubber is excellent in bending fatigue and abrasion resistance.In addition, since the hindered amine light stabilizer is compounded, the light stability to sunlight is good, Without discoloration or fading, the color rubber of the present invention is merely placed and pasted on the side wall rubber surface in advance in the tire molding process, and thereafter formed in the usual molding and vulcanization processes. Therefore, the process is easy, and as a result, the tire of the present invention functions as an advertising medium for corporate image enhancement by corporate colors, Also to flame prevention it is extremely effective.
[0012]
【Example】
Next, an embodiment of the present invention will be described with reference to FIG. 1, but it goes without saying that the present invention is not limited to this.
[0013]
In the figure, a tire 1 of the present invention includes an annular tread portion 2 and a pair of left and right beads 3, 3. The tire 1 extends from both ends of the tread portion 2 to a pair of left and right beads 3, 3. A sidewall section 4 is provided. The carcass layer 5 is mounted on the bead cores 3 ', 3' constituting the pair of right and left bead portions 3, 3 in the radial direction of the tire by winding the bead cores 3 ', 3'. Between them, four belt layers 6 are disposed in the rubber over the entire area of the tread portion 2. In the present invention, in the tire after vulcanization, a narrow band of the color rubber 7 is applied to the outer surface of the sidewall portion 4 and slightly near the bead portion 3 in parallel with the tire circumferential direction and over the entire circumference. In a tire molding step, the rubber was placed on the rubber outer surface of the sidewall portion in advance, and then molded and vulcanized. In this case, in this example, the color rubber C is formed over the entire circumference in the tire circumferential direction in the tire sidewall portion, but may be partially formed without extending over the entire circumference.
[0014]
Next, in the color rubber compounding systems shown in Tables 1 and 2, the light resistance test was performed in comparison with the total samples 1 to 16 of the tire of the present invention (Examples 1 to 11) and the comparative tires (Comparative Examples 1 to 5). Was performed.
In addition, the compounding quantity of the light stabilizer in Table 1 and Table 2 shows a weight part with respect to 100 weight part of rubber components.
[0015]
A test tire A tire having a tire size of 11.00 R22.5 and a tire of the present invention and a comparative tire having the same size and the same rubber composition as the sample No. shown in Table 1 were used. The number was made. That is, a color rubber tape having a width of 30 mm and a thickness of 1 mm, which was similarly extruded with the compounding system shown in Table 1 (all compounding amounts are shown in terms of parts by weight with respect to 100 parts by weight of rubber), was previously coated on the rubber surface of the sidewall portion. The tire was molded and vulcanized while being mounted on the entire circumference in parallel with the circumferential direction. As shown in FIG. 1, the position of the color rubber is in the entire circumferential area outside the bead portion in the tire radial direction and slightly closer to the bead portion than the tire maximum width.
[0016]
B test method (1) Outdoor exposure test Each test tire was left outdoors for one week with the exposed surface facing south, and the discoloration degree of the color rubber at that time was quantified as an index of light resistance. These were ranked and displayed in five stages of 1 to 5 (the numerical value was better).
(2) UV exposure test After irradiating the test tires with UV rays for 24 hours using a Stanley sun lamp of 100 volts and 250 watts, the degree of discoloration of the color rubber at that time was quantified as an index of light resistance. The results are ranked and displayed on five levels (up to better numerical values).
[0017]
The basic composition of the color rubber is as follows.
◎ Basic blend of color rubber Natural rubber 50 parts by weight Polybutadiene rubber 20
Chlorinated butyl rubber 30
Titanium oxide 20
Clay 30
Zinc flower 5
Stearic acid 2
Paraffin wax 5
Vulcanization accelerator CBS 1
(Note 1)
Organic pigment 2
Note 1) Margin below N-cyclohexyl-2-benzothiazolylsulfenamide
[Table 1]

[0019]
[Table 2]

[0020]
The results of the light resistance test are shown in Table 1 for Examples 1 to 9, and Table 2 for Examples 10 and 11 and Comparative Examples. When H1 was blended as a hindered amine based light stabilizer of the present invention, when 5.0 parts by weight (Example 4) was blended with respect to 100 parts by weight of rubber, an outdoor exposure test and an ultraviolet exposure test were performed. Both are the highest, and when H2 is blended even with hindered amines, the best is when the benzontriazole is used in combination (Example 11). The highest value was obtained also when the hindered amine type H1 and the benzontriazole type were used in combination (Example 9). On the other hand, the light stability is not improved with light stabilizers other than hindered amines (see Comparative Examples). Therefore, it was recognized that the hindered amine type had excellent light fastness even in a compounded system used in combination with another light stabilizer.
[0021]
【The invention's effect】
The present invention has the following effects because it is configured as described above. That is, since the hindered amine compound is used as the light stabilizer, a light stabilizing effect superior to other light stabilizers acting as an ultraviolet absorber is exhibited. Further, since the light stabilizer of the present invention is a color rubber compound based on a rubber component, the compound may be a rubber compound excluding carbon black, and a rubber strip of the color rubber may be extruded. Since the rubber strip is formed by processing or the like, it is only necessary to place and stick the rubber strip in place on the rubber surface of the sidewall portion in advance in the tire forming process, and the color rubber strip is vulcanized in the tire vulcanizing process. It is vulcanized and adhered to the side wall surface so that it does not peel off, and even if it comes into contact with the curb of a road, it is resistant to damage because of its high rebound resilience. In particular, there is no need for a preliminary treatment for removing the amine-based anti-aging agent on the side wall surface to which the color rubber is adhered as in the prior art. Selection and application of color rubber is possible.
[Brief description of the drawings]
FIG. 1 is a partial perspective explanatory view showing a half section of an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Tire 2 Tread part 3 Bead part 3 'Bead core 4 Side wall part 5 Carcass layer 6 Belt layer C Color rubber strip

Claims (1)

In a pneumatic tire including an annular tread portion, and a pair of bead portions, and a sidewall portion extending from both end portions of the tread portion to the bead portion, carbon black is applied to an appropriate position of the sidewall portion. A pneumatic tire having a color rubber for identification, wherein a color rubber compounded with a hindered amine light stabilizer is formed as a color rubber compounding system containing no color rubber.

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