KR100563142B1 - Pneumatic tire - Google Patents

Abstract

The present invention relates to a tire in which a reinforcing agent is inserted into a groove and a cuff, and a rubber composition using natural rubber as a raw material rubber, silica as a filler, and a large amount of vulcanizing agent so that elasticity is very strong and energy loss is very small. Forming a reinforcing layer made of the inner side of the tire main pattern provides a tire that can maintain low tire fuel characteristics while maintaining other tire characteristics, such as braking force and wear performance.

Description

Pneumatic tire             

1 is a cross-sectional view of a pneumatic tire having a reinforcing layer formed inside the groove and cuff according to the present invention.

The present invention relates to a pneumatic tire, and more particularly, to a pneumatic tire having a reinforcing layer formed inside the groove and the cuff.

Recent developments in the tire industry have been expanding technology to produce low fuel consumption, low rolling resistance and environmentally friendly products. Initial attention has been made to improve the interaction between polymer and carbon black, the most widely used reinforcing agent.

However, silica has been proposed as a solution to the limitation of the characteristics of carbon black. However, due to the strong polarity of silica, miscibility with nonpolar rubber was not easy. In order to solve this problem, the coupling agent was introduced to improve the interaction force between silica and polymer, and the application of silica tire tire technology has been rapidly developed.

In addition, in terms of structural aspects, research results have been reported to reduce the overall rolling resistance by using a compound having a low loss energy in the rubber in a part not in contact with the ground by taking the tread in a laminated structure.

However, in the prior art, when the tire is designed with the desired rolling resistance level, other characteristics of the tire have a disadvantage of poor results.

Accordingly, the present inventors insert a reinforcing layer having high elastic properties and low energy loss inside the grooves and cuffs of the pneumatic tire, thereby effectively reducing the rolling resistance and preventing other performance degradation of the tire, in particular, the braking performance. However, it was found that the rotational resistance can be reduced while maintaining the wear performance, thereby completing the present invention.

Accordingly, an object of the present invention is to insert a reinforcing layer inside the groove and the cuff to effectively reduce the tread loss energy and to increase the rigidity of the tread pattern by using the reinforcing effect to improve the braking or wear characteristics of the pneumatic tire To provide.

Pneumatic tire of the present invention for achieving the above object is 100 parts by weight of natural rubber as a raw material rubber, a mixture of silica alone or carbon black as a reinforcing agent, coupling agent inside the tire groove (Groove) and kerf (Kerf) , A softening agent, a zinc oxide and stearic acid as a vulcanizing agent, a reinforcing layer made of a rubber comprising 3 to 7 parts by weight of a vulcanizing agent and 0.8 to 2 parts by weight of a vulcanization accelerator is characterized in that it is formed to a thickness of 0.3 to 10mm.

The present invention will be described in more detail as follows.

In order to solve the problems of the prior art, the pneumatic tire of the present invention uses a rubber product having excellent elastic properties and low energy loss as a reinforcing layer to improve a desired tire performance.

Specifically, the reinforcing layer is located inside the tire groove and the cuff, and the specific composition may be made of natural rubber as the raw material rubber and silica as the reinforcing agent, but carbon black may be mixed. In addition, the content of the vulcanizate is 3 to 7 parts by weight based on 100 parts by weight of the raw material rubber, and the content of the vulcanization accelerator is 0.8 to 2 parts by weight based on 100 parts by weight of the raw material rubber. In addition, the reinforcing layer rubber includes a coupling agent, a softener, and zinc oxide and stearic acid as vulcanizing agents.

In this case, the silica used in the reinforcing layer rubber composition includes all of the precipitated silica having a CTAB value of 125 to 400 m 2 / g, a BET value of 125 to 400 m 2 / g and a DOP value of 400 ml / 100 g or less. The content of silica is preferably 40 to 85 parts by weight based on 100 parts by weight of the raw rubber.

If the vulcanizing agent is used in the above range while using silica as a reinforcing agent in the reinforcing layer rubber composition, it is generally possible to reduce the loss energy while maintaining elasticity as compared with carbon black as the reinforcing agent or the content of the vulcanizing agent. have.

The reinforcing layer made of rubber of such a composition may be formed with a thickness of 0.3 to 10 mm inside the groove and the cuff. However, the reinforcing layer is not limited thereto. However, when the reinforcing layer is too thick, wear characteristics of the reinforcing layer rubber may be degraded due to bad abrasion resistance. As a result, it is preferable that a reinforcing layer be formed in this category.

The method of forming the reinforcing layer inside the tire groove and the cuff is not particularly limited, but may be performed by performing multiple extrusion during tread extrusion or partially laminating other additional rubber sheets.

As such, the tire having the reinforcing layer formed inside the tire groove and the cuff has improved low fuel efficiency and increases the groove and cuff inner stiffness to improve braking characteristics.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

(Production Comparative Examples 1 and 2)

As shown in the mixing ratios shown in Table 1 below, raw rubber, reinforcing agents (carbon black, silica), vulcanizing agents such as zinc oxide and stearic acid, vulcanizing agents and vulcanization accelerators, and coupling agents were added and mixed in a Banbury mixer and released at a constant temperature. . Divided into detailed steps, it can be divided into three steps.

Ⓐ Raw material rubber 2/3 reinforcing agent and coupling reagent (Comparative Example 2), zinc oxide and stearic acid were added and mixed in Banbury mixer and then released at 160 ° C.

Ⓑ 1/3 of the reinforcing agent and the coupling reagent (Comparative Example 2) were added to the rubber (ⓐ) blended above, mixed in a Banbury mixer, and then discharged at 160 ° C.

Ⓒ The vulcanizing agent and the vulcanization accelerator were added to the rubber compounded in the above (ⓑ) and mixed in a Banbury mixer, and then released after a predetermined time (1 minute 30 seconds).

Physical properties of the rubber products prepared by the above method are shown in Table 2 below.

 (Production Examples 1 to 3)

Except for the addition of variable amounts of filler N326 or silica was mixed in the same manner as in Preparation Example 1, the physical properties of the rubber products are shown in Table 2 below.

Mixed composition Comparative Example 1 Comparative Example 2 Preparation Example 1 Preparation Example 2 Preparation Example 3 Natural Rubber (NR) 100 100 100 100 100 Carbon black n326 55 - 20 - - Silica 1 - - - 52 - Silica 2 - 60 40 - 60 Coupling Reagent (Si-69) - 4.6 4.6 4.6 4.6 Zinc oxide 6 6 6 6 6 Stearic acid 1.2 1.2 1.2 1.2 1.2 Antioxidant 1.8 1.8 1.8 1.8 1.8 brimstone 4.5 2 4.5 4.5 4.5 Accelerator (TBBS) 1.4 1.5 1.4 1.4 1.4 Silica 1: Ultrasil VN3 (Degussa), precipitated silica having a CTAB value of 160 m 2 / g, a BET value of 180 m 2 / g and a DOP value of 200 ml / 100 g. Silica 2: Zeosil 1165 MP (Rhodia), precipitated silica having a CTAB value of 150 m 2 / g, a BET value of 150 m 2 / g and a DOP value of 220 ml / 100 g.

Mixed composition Comparative Example 1 Comparative Example 2 Preparation Example 1 Preparation Example 2 Preparation Example 3 100% Modulus (Mpa) 6.0 5.3 4.8 6.2 6.7 300% Modulus (Mpa) 12.0 10.1 10.2 11.6 12.3 Elongation (%) 480 510 540 495 485 0 ℃ tan δ 0.530 0.575 0.560 0.591 0.585 60 ℃ tan δ 0.136 0.106 0.121 0.113 0.071

※ 0 ℃ tanδ: Braking characteristic. The higher the value, the better the performance.

※ 60 ℃ tanδ: It shows the rotation resistance The lower the value, the better the performance.

From the results of Table 2, it can be seen that the elastic properties are maintained when the natural rubber is used as a raw material rubber, a large amount of vulcanizing agent is added, and silica is used as the reinforcing agent, and the loss energy can be reduced.

(Examples 1 to 3 and Comparative Example 1)

Using the rubber of Preparation Example 3 showing the best physical properties of the rubber composition obtained through the above production examples to prepare a finished tire product formed with a reinforcing layer in the groove. Specifically, the tire finished product as the standard P205 / 55R16, was produced by forming a reinforcing layer as a thickness as shown in Table 3 inside the groove through a multiple extrusion method.

However, in Comparative Example 1, no reinforcing layer was formed, and in Comparative Example 2, the thickness of the reinforcing layer was 15 mm.

The characteristics of the tires thus obtained were compared, and the results are shown in Table 3 below.

Tire manufacturer Comparative Example 1 Comparative Example 2 Example 1 Example 2 Groove Inner Reinforcement X ○ (15 mm thick) ○ (2 mm thick) ○ (5 mm thick) Low fuel consumption 100 104 102 105 Wet Road Braking Characteristics 100 101 101 103 Wear characteristics 100 97 100 102

As a result of inserting the high elastic rubber layer into the groove and the cuff from the results of Table 3, the rotation resistance performance was the best and the braking characteristics were improved under the condition of 5 mm thickness of the reinforcing layer. However, it can be seen that when the thickness of the reinforcing layer is 15 mm, the performance of wear characteristics is degraded due to the bad wear resistance of the reinforcing layer rubber.

As described in detail above, in the case of a tire including silica as a reinforcing agent according to the present invention, a reinforcing layer made of rubber which reduces elasticity while maintaining elasticity by using a specific amount of vulcanizing agent inside the groove and the cuff. It can be seen that the low fuel consumption characteristics are improved, and the braking characteristics are improved by increasing the groove and cuff inner stiffness.

Claims (3)

100 parts by weight of natural rubber as a raw material rubber, a mixture of silica alone or carbon black as a reinforcing agent, a coupling agent, a softener, a vulcanizing agent, zinc oxide and stearic acid, and a vulcanizing agent inside the tire grooves and kerfs. A pneumatic tire formed such that a reinforcing layer made of rubber including 7 parts by weight and 0.8-2 parts by weight of vulcanization accelerator is 0.3 to 10 mm thick. The pneumatic tire according to claim 1, wherein the reinforcing layer rubber comprises silica in an amount of 40 to 85 parts by weight based on 100 parts by weight of the raw material rubber. The method of claim 1, wherein the silica in the reinforcing layer rubber is precipitated silica, CTAB value of 125 ~ 400 m 2 / g, BET value of 125 ~ 400 m 2 / g and DOP value of 400ml / 100g or less characterized in that tire.

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