KR20030019978A - Capply Cord Sheet for Wrapping Steel Cord near located by Belt Edge with Incresed durability for Tire - Google Patents

Abstract

PURPOSE: A cap ply cord fabric for wrapping a steel cord of a belt edge of an air pressure tire is provided to prevent an end portion of the steel cord from moving back and forth by making up plural fabric cords in a weaving form. CONSTITUTION: A ply cord fabric for wrapping a steel cord of a belt edge is made up of plural fabric cords(8) in a weaving form. The ply cord fabric is topped by a rubber composition(9). Herein, the rubber composition is composed of 40 to 50 weight of carbon black of which nitrogen absorption surface area is 80 to 120m2/g and DBP absorption amount is 70 to 120 cc/100g and high intensity rubber composition of which JIS-A hardness is 70 to 85 by adding less than 10 weight of aromatic processing oil to 100 weight of raw rubber made up of natural rubber alone or mixed rubber with synthetic rubber. Thereby, the up/down and right/left movement of the belt edge is minimized and separation upon traveling at a high speed is prevented.

Description

{Capply Cord Sheet for Wrapping Steel Cord near located by Belt Edge with Incresed durability for Tire}

The present invention relates to a ply cord paper for wrapping a steel cord of a belt edge portion of a pneumatic tire, and more particularly, a ply code for plying an edge portion of a belt edge portion having improved durability by a capply cord paper including a plurality of woven fabric cords. It's about code.

Existing pneumatic tires required reinforcement of the belt area for improved durability. Especially, the belt edge area has a belt angle of 20 ° to 30 ° for small pneumatic tires and 20 ° to medium to large pneumatic tires. It has a 60 ° angle, which generates heat as the steel cord moves on the belt edge at high speeds, and this heat is one of the important reinforcement parts as a starting point leading to separation by reducing the adhesion between the steel cord and rubber. .

The method of reinforcing the belt part may include a full capply (FIG. 1) covering the entire belt upper layer, an edge capply (FIG. 2) covering only the belt edge part, or a mixture of a full capply and an edge capply. There is a method of using, and the like, and recently, a technique of wrapping the belt edge portion with coded paper is introduced as shown in FIG. 3. All of these methods are commonly aimed at improving the durability by preventing movement at high speed by minimizing the movement of belt parts, especially belt edges, in pneumatic tires.

However, as shown in FIG. 1 and FIG. 2, the pneumatic tire to which the conventional full cap ply or edge ply is applied can prevent movement of the belt in the vertical direction, but the effect of preventing the movement in the left and right directions is lowered. The fabric cords of FIGS. 1 and 2 covering the edges only slightly improve the effect of holding the belt end portions from the top and the bottom, respectively, rather than the method of FIGS. 1 and 2 to catch the movement in the vertical direction of the belt edges. (5, 6) and the direction of the fabric cord 7 of FIG. 3, which is lepping, are all applied with 0 ° to ± 10 ° (mostly 0 °) of the circumferential direction of the tire as in the fabric cord 8 of FIG. As a result, there is almost no effect of catching the steel cord tip moving left and right when using pneumatic tires.

(In the drawings, reference numerals 1 and 2 denote known first and second steel cords, and reference numerals 3 and 4 denote first and second body plies.)

An object of the present invention is to prevent the steel cord end portion from moving in the left and right direction as described above, a belt edge region rep is composed of a plurality of fabric cords woven by fleeing the fly structure applying the conventional straight fabric cord Ply coded paper for ping.

1 is a cross-sectional view of a conventional full cap fly in use.

2 is a cross-sectional view of a state of use of a conventional edge cap ply;

Figure 3 is a cross-sectional view of the conventional belt edge portion wrapping cap ply use state.

4 is a state in which the conventional cap fly code is actually applied.

5 is a conventional general straight capply cord paper.

Figure 6 is a woven capply cord paper of the present invention.

<Code Description of Main Parts of Drawing>

1: first belt steel cord 2: second belt steel cord

3: first body fly 4: second body fly

5: Fabric cord of full capfly 6: Fabric cord of edge capfly

7: fabric cord of belt edge wrapping ply

8: Fabric cord of belt edge cap ply or belt edge wrapping ply

9: Topping Rubber Composition

The present invention relates to a ply cord paper for wrapping a steel cord of a belt edge portion of a pneumatic tire, wherein the ply cord paper includes a plurality of woven fabric cords and a rubber composition for topping the woven fabric cords. Contains fly coded paper.

The fabric cord is formed in a woven form, preferably formed so that one direction of the woven cord is located within the range of -10 ° to 10 ° with the tire circumferential direction, and more preferably, maintained at 0 °. In addition, the rubber composition topping the woven fabric cord (9 in Figure 6) does not require a special limitation as long as it satisfies the characteristics of low heat generation, high strength.

Examples of the rubber composition that satisfies the above requirements are preferably nitrogen adsorption with respect to 100 parts by weight of raw rubber composed of natural rubber alone or mixed rubber with synthetic rubber (synthetic rubber is preferably added in an amount of 30 parts by weight or less). 40 to 70 parts by weight of carbon black having a specific surface area of 80 to 120 m ² / g, DBP oil absorption of 70 to 120 cc / 100 g, and 10 parts by weight or less of aromatic process oil to satisfy JIS-A hardness of 70 to 85 range. There is a high strength rubber composition.

When the nitrogen adsorption specific surface area of the carbon black used in the present invention is less than 80, the strength of the belt edge portion cannot be strengthened, and when it exceeds 120 m ² / g, the dispersion property of the carbon black is poor and the rubber heat is increased, so that the It is not suitable for rubber compositions, and carbon black's DBP oil absorption is less than 70cc / 100g. Since normal dispersion of black is difficult, it is preferable to use carbon black in the present invention having a nitrogen adsorption specific surface area of 80 to 120 m ² / g and a DBP oil absorption of 70 to 120 cc / 100 g.

Carbon black is basically an important additive that shows the strength of the rubber composition. If it is less than 40 parts by weight based on 100 parts by weight of the raw material rubber in the present invention, it is difficult to produce sufficient strength as the rubber composition used for the belt edge portion, and it is used more than 70 parts by weight. If the lower end of the rubber product heats up the properties of the rubber may cause separation of the tire (separation) accident, the carbon black in the present invention is preferably used 40 to 70 parts by weight.

The aromatic process oil is an additive for improving processability. In the present invention, when the carbon black is used in an amount of up to 70 parts by weight, the aromatic process oil is preferably added in an amount of 10 parts by weight or less. It is good.

If the JIS-A hardness of the rubber composition is less than 70, the strength of the steel cord lapping rubber composition that reinforces the belt edge is too low, so it is difficult to expect a sufficient effect. Since there is a disadvantage in decreasing, it is preferable that the JIS-A hardness satisfy the range of 70 to 85.

Preferably the hardness in the above is required to be 3 to 10, more preferably about 5 higher than the steel belt topping rubber composition due to the reason that the movement at the belt edge portion of the tire running more than the inside of the belt.

Other rubber compositions of the present invention may include conventional additives such as zinc oxide, adhesives, pressure-sensitive adhesives, anti-aging agents, sulfur and vulcanization accelerators, but these are obvious to those skilled in the art. As a matter of course, detailed description thereof will be omitted.

The rubber composition that satisfies the above requirements is preferably formed with a thickness of 0.8 to 1.5 mm when topping the cord. For this reason, if it is less than 0.8 mm, the strength for the belt edge reinforcement required by the present invention is weak, and if it is more than 1.5 mm, the thickness of the tire shoulder part is not uniform because it is too thick as a topping paper surrounding the belt edge. The problem arises.

The upper and lower widths (W ₀ of FIG. 3) of the cord to be lepped to the belt edge portion of the belt edge portion configured as described above are preferably set to at least 30 mm or more to increase the reinforcing effect.

Hereinafter, the contents of the present invention will be described in detail through examples. However, the following examples are intended to illustrate the present invention in more detail, and are not intended to limit the scope of the invention.

Comparative Example 1

50 parts by weight of N330 (HAF) as carbon black based on 100 parts by weight of a raw material rubber composed of 80 parts by weight of natural rubber (NR) and butadiene rubber (BR), as shown in the compounding ratio (A composition) disclosed in Table 1 below. 4 parts by weight of zinc oxide, 2 parts by weight of anti-aging agent, 3 parts by weight of adhesive, 3 parts by weight of adhesive, 7 parts by weight of aromatic process oil, 3.0 parts by weight of sulfur and 0.5 parts by weight of vulcanization accelerator were added to the Banbury mixer, and the temperature was 160 ° C. Emitted at

Physical properties of the resulting rubber was measured by the ASTM standard method and the results are shown in Table 1.

In addition, the rubber composition as a topping rubber to produce a full cap ply composed of a general straight fabric cord as shown in Figure 5 applied to a tire of the 195 / 60R14 standard in the same manner as in Figure 1 and measured the durability results Table 2 Shown in

Comparative Example 2

Topping rubber composition was used as the same as in Comparative Example 1 (A composition),

Using the rubber composition as a topping rubber, a belt edge wrapping capply composed of a general straight fabric cord as shown in FIG. 5 was manufactured, and applied to a tire of 195 / 60R14 standard in the same manner as in FIG. 3 and measured for durability. 2 is shown.

<Example 1>

Topping rubber composition was used as the same as in Comparative Example 1 (A composition),

Using the rubber composition as a topping rubber, a belt edge wrapping capply composed of a woven fabric cord as shown in FIG. 6 was manufactured, and applied to a tire of 195 / 60R14 standard in the same manner as in FIG. 3 and measured for durability. 2 is shown.

<Example 2>

The topping rubber composition used B composition of Table 1,

Using the rubber composition as a topping rubber, a belt edge wrapping capply composed of a woven fabric cord as shown in FIG. 6 was manufactured, and applied to a tire of 195 / 60R14 standard in the same manner as in FIG. 3 and measured for durability. 2 is shown.

<Example 2>

Topping rubber composition was used in the C composition of Table 1,

Using the rubber composition as a topping rubber, a belt edge wrapping capply composed of a woven fabric cord as shown in FIG. 6 was manufactured, and applied to a tire of 195 / 60R14 standard in the same manner as in FIG. 3 and measured for durability. 2 is shown.

TABLE 1 Topping Rubber Composition

Composition A B C NR 80 100 80 SBR 0 0 20 BR 20 0 0 N330 (HAF) 50 50 0 N326 (L / S HAF) 0 0 60 Zinc oxide 4 3 3 Anti-aging 2 3 3 glue 3 3 5 adhesive 3 2 2 Aromatic process oil 7 5 5 brimstone 3.0 3.5 3.7 Vulcanization accelerator 0.5 1.0 0.8 JIS-A Hardness 65 73 78 300% modulus (kgf / cm ² ) 130 155 195 H.B.U (Δ ° C.) 30 35 36 Characteristic General Straight Fabric Cord Topping Rubber Composition General Steel Belt Cord Topping Rubber Composition High Strength Woven Fabric Cord Topping Rubber Composition

<Table 2> Tire durability evaluation results

Exam Content Example 1 Example 2 Example 3 Example 4 Example 5 Cap fly method Molding method Full cap fly (Fig. 1) Belt edge wrapping cap ply (Fig. 3) Belt edge wrapping cap ply (Fig. 3) Belt edge wrapping cap ply (Fig. 3) Belt edge wrapping cap ply (Fig. 3) Usage code 5 code 5 code 6 code 6 code 6 code Topping rubber composition (Table 1) A A A B C Tire weight 8.5 kg 8.2kg 8.2kg 8.2kg 8.2kg ECE-R30 (HR Speed Condition) Driving time 1 hour 20 minutes 1 hour 25 minutes 1 hour 25 minutes 1 hour 30 minutes 1 hour 40 minutes Thinking Tread peeled Tread peeled Belt edge breaking Belt edge breaking Belt edge breaking

As can be seen from the above results, in the case of the conventional straight cap fly method, it can be seen that the durability of the tread is peeled off. On the other hand, the experiment under the same conditions shows that the woven cap fly coded paper according to the present invention. When applied, it can be confirmed that the durability is improved to the extent that the belt edge portion is destroyed.

In addition, as a result of applying the high-strength rubber composition C composition it can be confirmed that the durability is greatly improved by holding the belt edge effectively.

According to the present invention, as a result of applying a high-strength low-heat topping rubber to the woven fabric cord, it is possible to minimize the left and right movements of the belt portion, in particular, the belt edge portion of the tire as much as possible, thereby preventing the separation at high speed and greatly improving the durability. It works.

Claims (5)

A cap ply cord paper for wrapping a steel cord of a belt edge portion of a pneumatic tire, the cap ply cord paper comprising a plurality of woven fabric cords and a rubber composition to topping the woven fabric cords Flycoded paper. The cap ply cord paper according to claim 1, wherein one direction of the woven cord is formed to be within a range of -10 ° to 10 ° with the tire circumferential direction. The rubber composition according to claim 1, wherein the rubber composition topping the woven fabric cord has a nitrogen adsorption specific surface area of 80 to 120 m ² / g and a DBP oil absorption amount based on 100 parts by weight of the raw material rubber composed of natural rubber alone or mixed rubber with synthetic rubber. A cap ply cord paper comprising 40 to 70 parts by weight of carbon black having 70 to 120 cc / 100 g and 10 parts by weight or less of aromatic process oil to a high strength rubber composition having a JIS-A hardness of 70 to 85. The cap ply cord paper according to claim 3, wherein the thickness of the topping of the ply cord paper is 0.8 to 1.5 mm. A pneumatic tire manufactured by setting the upper and lower widths of the cord for wrapping the cap fly cord paper of any one of claims 1 to 4 to at least 30 mm or more.