JP2003246209A - Diene based rubber molded article, tire and its die - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diene based rubber molded article wherein the deterioration of appearance due to cracks generated on a rubber surface is suppressed, and to provide a tire and its die. <P>SOLUTION: For this diene based rubber molded article, a plurality of recesses 1 each having a width W of 0.05 to 0.1 mm and a depth d of 0.01 to 0.1 mm, and/or protrusions 2 each having a width W of 0.05 to 0.1 mm, and a height h of 0.01 to 0.1 mm are formed at pitched P of 0.1 to 0.5 mm on the surface. Then, a plurality of recesses each having a width of 0.05 to 0.1 mm and a depth of 0.01 to 0.1 mm, and/or protrusions having a width of 0.05 to 0.1 mm and a height of 0.01 to 0.1 mm are formed at pitches of 0.1 to 0.5 mm on the surface of the sidewall for this tire. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diene rubber molded product, a tire and a mold thereof, and more specifically, a diene rubber molded product, a tire and a metal mold thereof in which appearance deterioration due to cracks generated on a rubber surface is suppressed. Regarding the type.

[0002]

2. Description of the Related Art Rubber products such as tires, especially rubber products containing a diene rubber, are usually attacked by ozone in the atmosphere,
The surface cracks with the passage of time. The degree of occurrence of this changes depending on the composition of the rubber composition and how the dynamic strain is applied under the conditions of use of the rubber product, but ozone deterioration occurs to some extent and cracks occur on the rubber surface. , The appearance deteriorates.

In order to mitigate / suppress this phenomenon, the amount of antioxidants represented by amine compounds, waxes and liquid polymers, and the amount of carbon black and plasticizers such as oils have been increased in conventional rubbers. Etc. are generally performed.

However, when these compounding agents are compounded or the compounding amount is increased, there are problems that other physical properties of the rubber are deteriorated and that the rubber compounding is restricted and the degree of freedom is lost. Anti-aging agents are generally expensive, and when added in large amounts, the cost of the rubber composition increases, and when wax is mixed, the wax blooms (migrates) to the rubber surface during the use of the rubber product, and There was also a problem of deteriorating the appearance of the product.

[0005]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a diene rubber molded article, a tire, and a mold for the same, in which deterioration of the appearance due to cracks generated on the rubber surface is suppressed.

[0006]

According to the present invention, a width of 0.
05-0.1 mm, depth 0.01-0.1 mm recess,
And / or width 0.05-0.1 mm, height 0.0
Provided is a diene-based rubber molded product in which a plurality of convex portions of 1 to 0.1 mm are provided at a pitch of 0.1 to 0.5 mm.

According to the present invention, the sidewall surface has a width of 0.05 to 0.1 mm and a depth of 0.01 to 0.1 m.
m recess and / or width 0.05-0.1 mm,
0.1-0.5 mm height 0.01-0.1 mm convex
There is provided a plurality of tires provided at a pitch of.

Further, according to the present invention, there is provided the diene rubber molded article or the tire, wherein the shape of the concave portion or the convex portion is a linear shape, a wavy shape, a zigzag shape, or a fawn pattern.

According to the present invention, the width of the surface is 0.05.
-0.1 mm, height 0.01-0.1 mm, and / or width 0.05-0.1 mm, depth 0.01-
Provided is a mold for a diene-based rubber molded product, in which a plurality of 0.1 mm concave portions are provided at a pitch of 0.1 to 0.5 mm.

Further, according to the present invention, the width of the sidewall portion is 0.05 to 0.1 mm and the height is 0.01 to 0.1 mm.
0.1 mm convex portion and / or width 0.05-0.
1 mm, depth 0.01-0.1 mm recess 0.1
A metal mold for a tire provided with a plurality of pitches of 0.5 mm is provided.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The size of the recess 1 provided on the surface of the rubber molded article of the present invention or on the surface of the sidewall of the tire has a width W of 0.05 to 5, as shown in the sectional view of FIG.
0.1 mm, depth d is 0.01 to 0.1 mm, and the protrusion 2 has a width W of 0.0 as shown in the sectional view of FIG.
It is 5 to 0.1 mm and the height h is 0.01 to 0.1 mm. A plurality of these concave portions and convex portions are provided at a pitch P of 0.1 to 0.5 mm. With such a size and pitch, it becomes difficult for the naked eye to see, there is no adverse effect on the appearance, and the design of the product is not deteriorated.
For example, it is possible to form the concave portions 1 and the convex portions 2 on the entire surface area or large area of the rubber product without a feeling of strangeness.

Further, even if a crack is generated on the rubber surface due to ozone deterioration or the like, the crack easily progresses along the above-mentioned concave portion 1 or convex portion 2 at a level of a micro size, so that the crack is generated. Since the particles are dispersed and buried and become substantially invisible to the naked eye, it is possible to effectively prevent the deterioration of the appearance.

The width W, the depth d of the concave portion 1 and the convex portion 2 of the present invention,
If the height h and the pitch P are too smaller than the above sizes, the effect of suppressing the deterioration of the appearance due to the cracks of the present invention cannot be obtained, and the manufacturing becomes difficult. Conversely, the width W,
If the depth d and the height h are too large, the concave portions and the convex portions are easily visible to the naked eye and the appearance deteriorates. If the pitch P is too large, the effect of suppressing the deterioration of the appearance due to cracking of the present invention cannot be obtained.

The shape of the concave portion or the convex portion of the present invention is not particularly limited and may be any shape. For example, the linear shape shown in FIG. 3, the corrugated shape shown in FIG. 4, the zigzag shape, or A fawn pattern as shown in FIG. 5 may be mentioned, but a straight line shape is particularly preferable because it is easy to manufacture.

In order to form the recesses and protrusions provided on the surface of the rubber molded product or tire of the present invention, the protrusions and recesses of the same size are provided on the surface of the mold for producing the rubber molded product or tire. Good. That is, on the surface of the die-mold rubber molded article die or on the surface of the sidewall of the tire die, a width of 0.
05-0.1 mm, height 0.01-0.1 mm convex portion,
And / or width 0.05-0.1 mm, depth 0.0
The recesses of 1 to 0.1 mm may be provided at a pitch of 0.1 to 0.5 mm. The mold is not limited to metal such as iron and aluminum alloy, but any material such as resin can be used.

The rubber of the diene rubber product of the present invention contains a diene rubber, but may be a blend of other rubbers. Examples of the diene rubber include natural rubber (NR), polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), acrylonitrile-butadiene copolymer rubber (NBR), ethylene-propylene. -Diene copolymer rubber (EPDM) and the like may be mentioned, and a blend thereof may be used.

As the diene rubber molded article, various products can be used and are not particularly limited, but they can be suitably used particularly for products that are repeatedly deformed. Specifically, in addition to tires, rubber bushes for automobiles, hoses, conveyor belts, fenders, rubber bands for bundling, etc. may be mentioned.

[0018]

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. A pneumatic radial tire for passenger cars having a tire size of 205 / 65R15 was produced. As shown in FIGS. 1 and 3, a large number of metal molds are used as shown in FIGS. Recess on the straight line 1
The tire of Example 1 in which (width W = 0.05 mm, depth d = 0.03 mm, pitch P = 0.3 mm) was formed was manufactured by a conventional method.

As the tire of Example 2, the linear concave portion 1
As (width W = 0.1 mm, depth d = 0.05 mm,
Example 1 except that the pitch P = 0.4 mm) was formed.
Was prepared in the same manner as in.

Further, as the tire of the comparative example, the width W =
0.5 mm, depth d = 0.1 mm, pitch P = 0.5 m
A tire similar to that of Example 1 was manufactured except that the concave portion 1 was formed by m.

After observing the side wall surface of each of the obtained tires, an indoor drum tester was used to obtain a density of 10
While spraying 0 pphm of ozone on the sidewall surface, a speed of 81% under the condition of 74% of the maximum load described in JATMA Y / B 2001 version and an internal pressure of 120 kPa.
After running at 2400 km for 2 km, the presence or absence of ozone cracks on the sidewall surface was observed.

In the tires of Comparative Examples, cracks could not be visually confirmed after the ozone test, but since the size of the concave portion 1 was too large, this was visible to the naked eye.
The appearance is inferior. On the other hand, Examples 1-2
In the tire of No. 1, the concave portion 1 was not visible to the naked eye, and the appearance was good. Further, the generation of cracks could not be confirmed with the naked eye even after the ozone test, and the deterioration of the appearance due to cracks could be effectively prevented.

[0023]

According to the present invention, the width of the surface is 0.05 to
0.1 mm, 0.01-0.1 mm deep recess and / or width 0.05-0.1 mm, height 0.01-
By providing a plurality of 0.1 mm convex portions at a pitch of 0.1 to 0.5 mm, it is possible to obtain a diene rubber molded article, a tire and a mold thereof, in which deterioration of appearance due to cracks generated on the rubber surface is suppressed. .

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rubber surface.

FIG. 2 is a sectional view of a rubber surface.

FIG. 3 is a front view of a rubber surface.

FIG. 4 is a front view of a rubber surface.

FIG. 5 is a front view of a rubber surface.

[Explanation of symbols]

1 recess 2 convex W width d depth h height P pitch

Claims (5)

[Claims] 1. A concave portion having a width of 0.05 to 0.1 mm and a depth of 0.01 to 0.1 mm and / or a width of 0.
A diene rubber molded article in which a plurality of convex portions having a height of 05 to 0.1 mm and a height of 0.01 to 0.1 mm are provided at a pitch of 0.1 to 0.5 mm. 2. A width of 0.05 to 0.
1 mm, 0.01-0.1 mm deep recess and / or width 0.05-0.1 mm, height 0.01-0.1
A tire provided with a plurality of mm convex portions at a pitch of 0.1 to 0.5 mm. 3. The diene rubber molded article or tire according to claim 1, wherein the shape of the concave portion or the convex portion is a linear shape, a wavy shape, a zigzag shape, or a fawn pattern. 4. A convex portion having a width of 0.05 to 0.1 mm and a height of 0.01 to 0.1 mm and / or a width of 0.
A mold for a diene rubber molded article in which a plurality of concave portions having a depth of 05 to 0.1 mm and a depth of 0.01 to 0.1 mm are provided at a pitch of 0.1 to 0.5 mm. 5. The width of the sidewall portion surface is 0.05 to
0.1 mm, height 0.01 to 0.1 mm convex portion and / or width 0.05 to 0.1 mm, depth 0.01 to
A tire mold having a plurality of 0.1 mm recesses provided at a pitch of 0.1 to 0.5 mm.