JP2003119322A - Nonblack rubber composition for tire and tire using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nonblack rubber composition for a tire, capable of improving brightness without extremely increasing a white pigment, and further to provide the tire using the rubber composition. SOLUTION: This nonblack rubber composition for the tire obtained by compounding the white pigment is obtained by compounding 0.05-2 pts.wt. fluorescent brightening agent with 100 pts.wt. rubber. The tire is obtained by arranging the nonblack rubber composition at least at a part of the outer surface of the tire. The amount of the compounded white pigment is preferably 15-35 pts.wt. based on 100 pts.wt. rubber.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a non-black rubber composition for tires and a tire using the same, and more specifically, a non-black rubber composition for tires capable of improving lightness without significantly increasing the amount of white pigment. TECHNICAL FIELD The present invention relates to a rubber composition and a tire using the same.

[0002]

2. Description of the Related Art Conventionally, it has been known to apply a non-black rubber composition such as a white rubber composition to a white ribbon such as a sidewall portion or a letter portion for the purpose of improving the visibility of a tire and producing fashionability. Has been. In order to obtain the brightness (whiteness) of this non-black rubber composition, a white pigment such as titanium dioxide is generally added. However, in order to further improve the visibility, it is necessary to increase the lightness of the non-black rubber composition by increasing the blending amount of the white pigment, but the white pigment such as titanium dioxide has a poor mixing property with the rubber. Poorly, there was a problem in production that mixing could not be performed or mixing took too long.

[0003]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a non-black rubber composition for tires, which can improve the brightness without significantly increasing the amount of white pigment, and a tire using the same. It is in.

[0004]

According to the present invention, in a non-black rubber composition for tires containing a white pigment, 0.05 to 2 parts by weight of an optical brightening agent is added to 100 parts by weight of rubber. A non-black rubber composition for a tire is provided.

As described above, by adding a small amount of a fluorescent whitening agent together with a white pigment to a non-black rubber composition for tires, the lightness (whiteness) of the rubber can be increased without adding a large amount of the white pigment.
Since it is possible to significantly improve the non-black rubber composition for a tire having improved lightness without causing the problem of deterioration of mixing properties when the lightness is increased by significantly increasing the white pigment. Can be provided. In addition, since it is not necessary to significantly increase the amount of the white pigment having a large specific gravity, it is possible to suppress an increase in the weight of the non-black rubber composition for tires and, in turn, a deterioration in fuel consumption of a vehicle due to an increase in the weight of tires.

Further, according to the present invention, it is preferable that the blending amount of the white pigment is 15 to 35 parts by weight with respect to 100 parts by weight of rubber.

Further, according to the present invention, there is provided a tire in which the non-black rubber composition for a tire is arranged on at least a part of the outer surface of the tire.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The non-black rubber composition for a tire of the present invention is a colored rubber which is white or colored in a color other than black, and a white ribbon or a white ribbon is provided on at least a part of the tire outer surface such as a sidewall portion. Arranged in any shape such as letter part,
It is intended to produce visibility and fashionability.

The white pigment blended in the present invention is not particularly limited, but examples thereof include titanium dioxide, zinc oxide, calcium carbonate, and lead white. The blending amount of the white pigment is not particularly limited as long as it can express the lightness of the non-black rubber composition for tires, but in order to exhibit more sufficient lightness, it is 15 to 3 with respect to 100 parts by weight of the rubber.
It is preferably 5 parts by weight, and more preferably 20 to 25 parts by weight. This is because when the amount is 15 parts by weight or more, the lightness of the rubber can be further increased, and when the amount is 35 parts by weight or less, the kneadability of the white pigment into the rubber can be improved. .

The fluorescent whitening agent of the present invention may be any one as long as it further improves the lightness of the non-black rubber composition for tires containing a white pigment, and the kind thereof is not limited, but for example, 2,5-bis (2-Benzoxazolyl) thiophene, 2,2- (1,2-ethenediyl-di-4,1-phenylene) bisbenzoxazole and the like can be mentioned. The compounding amount of the optical brightener is 0.05 with respect to 100 parts by weight of rubber.
˜2 parts by weight, preferably 0.15 to 0.5 parts by weight. If the amount is less than 0.05 parts by weight, the effect of improving the brightness cannot be sufficiently exhibited, and if the amount is more than 2 parts by weight, the effect of improving the brightness cannot be further obtained. is there.

Any rubber can be used as the rubber of the present invention. For example, natural rubber (NR), butadiene rubber (BR), styrene-butadiene copolymer rubber (S
BR), polyisoprene rubber (IR), butyl rubber (I
IR), halogenated butyl rubber _{such as chlorobutyl rubber ( Cl-IIR)} , acrylonitrile butadiene rubber (N
BR), chloroprene rubber, ethylene propylene copolymer rubber, ethylene propylene diene copolymer rubber (EP
DM) etc. can be used, and these can be used individually or as a blend of 2 or more types.

The rubber composition of the present invention may contain a compounding agent usually used in the rubber industry, if necessary.
Examples of the compounding agent include fillers, process oils, vulcanizing agents, vulcanization accelerators, vulcanization activators, antioxidants, plasticizers, colorants such as pigments and dyes other than white, Each of them can be blended in a necessary amount so that the color of rubber is not adversely affected.

As the filler, it is not preferable to add carbon black that will color the rubber black, and it is preferable not to add carbon black substantially. Also, as a filler,
White fillers such as silica, talc and clay can be added.

The rubber composition of the present invention is produced by mixing the above components using a known rubber kneading machine such as a roll, a Banbury mixer or a kneader.

[0015]

The present invention will be further described below with reference to examples, but the scope of the present invention is not limited to these examples. Examples 1 to 3 and Comparative Examples 1 and 2 White non-black rubber compositions for tires having the respective formulations (weight ratios) shown in Table 1 below were prepared, and the following mixing properties were evaluated and heat vulcanization was performed. A test sample was prepared by the above and subjected to the following tests.

L ^* value It shows whiteness in CIE-1976 (L ^* a ^* b ^* ) color space, and was measured according to JIS Z8722. Visual whiteness Visually observe the rubber surface and check the whiteness in descending order.
The evaluation was made in four levels of ○ → △ → ×.

Mixing Workability When the unvulcanized rubber composition is mixed for 10 minutes, the case where the white pigment is sufficiently incorporated into the rubber is ○, and the case where the white pigment is not incorporated into the rubber and the mixing is insufficient. Was designated as x. Specific gravity (index) The specific gravity of the rubber composition was measured and indicated as an index value when Comparative Example 1 was set to 100.

[0018]

[Table 1]

The following components were used as the components used in Table 1 above. White pigment: Titanium dioxide fluorescent whitening agent: 2,5-bis (2-benzoxazolyl) thiophene, UVITEBOB, Ciba Geigy vulcanization accelerator NS: Nt-butyl-2-benzothiazolylsulfenamide vulcanization accelerator DT-O: Dioltotolyl guanidine

As shown in Table 1, in Comparative Example 2 in which the amount of the white pigment was increased by 10 parts by weight, the whiteness was increased as compared with Comparative Example 1, but the mixing workability was deteriorated and the specific gravity of the rubber was also increased. Oops. This is because a large amount of white pigment needs to be increased in order to sufficiently increase the whiteness by increasing the amount of white pigment. On the other hand, the non-black rubber compositions for tires of Examples 1 to 3 in which a small amount of the fluorescent whitening agent was blended did not adversely affect the mixing workability and the rubber weight without increasing the amount of the white pigment, and the brightness (white The good result that the degree) can be improved was obtained.

[0021]

INDUSTRIAL APPLICABILITY According to the present invention, a non-black rubber composition for tires containing a white pigment is added to 100 parts by weight of rubber.
By adding 0.05 to 2 parts by weight of a fluorescent whitening agent, it is possible to obtain a non-black rubber composition for a tire and a tire using the same, which can improve the brightness without significantly increasing the white pigment. it can.

Claims (3)

[Claims] 1. A non-black rubber composition for tires containing a white pigment, wherein 0.05 to 2 parts by weight of a fluorescent whitening agent is added to 100 parts by weight of rubber. 2. The non-black rubber composition for a tire according to claim 1, wherein the blending amount of the white pigment is 15 to 35 parts by weight with respect to 100 parts by weight of the rubber. 3. A tire in which the non-black rubber composition for a tire according to claim 1 or 2 is disposed on at least a part of the outer surface of the tire.