KR20050051008A - Tread compound improved fatigue property - Google Patents

Abstract

The present invention relates to a rubber composition for tires with improved fatigue resistance, and more particularly, to include a zinc acetate (Zinc acetate, Zn (CH ₃ COO) ₂ .2H ₂ O) in a known tire rubber composition. It relates to a rubber composition for a tire that can improve the dispersibility and improve fatigue resistance.

The present invention is to provide a rubber composition for a tire that can improve the fatigue resistance by improving the dispersibility of the reinforcing filler in the known rubber composition for the tire, including zinc acetate (Zinc acetate). Another object of the present invention is to provide a tire having improved fatigue resistance by including a rubber made of the rubber composition in the tire.

In the known rubber composition for tires, the present invention may include 1.5 to 2.5 phr of zinc acetate (Zn (CH ₃ COO) ₂ · 2H ₂ O) with respect to 100 phr of rubber.

In the present invention, the rubber composition may further use a reinforcing filler 57 to 60 phr, a vulcanizing agent (80% -CRYSTEX) 3.5 to 3.75 phr, and a vulcanization accelerator 0.7 to 0.9 phr with respect to 100 phr of raw rubber to improve fatigue resistance. .

Description

Rubber compound for tires with improved fatigue resistance

The present invention relates to a rubber composition for tires with improved fatigue resistance, and more particularly, to include a zinc acetate (Zinc acetate, Zn (CH ₃ COO) ₂ .2H ₂ O) in a known tire rubber composition. It relates to a rubber composition for a tire that can improve the dispersibility and improve fatigue resistance.

The use of tires in the early days of the automobile invention was used only as a function of simple vehicle support and movement. However, over time, consumer demands for tires are rapidly changing, and as the technology develops, the performance of tires is proportionally improved as the vehicle's performance improves. Therefore, it is urgent to develop tires with new performance.

Tires have inherent characteristics depending on the main use, and the most important characteristics of truck / bus tires are long-term use. In particular, tires for trucks / buses are relatively expensive products and there are many variations in the service life due to tire performance, so it is essential to develop products that can be used for a long time while maintaining constant performance. In addition, since consumers are required to additionally use regeneration according to long-term use, it is very important to maintain fatigue characteristics according to long-term use of tires.

Recently, tires are required to have the same performance as new tires, not only for long-term use of new tires, but also for recycled tires. In order to maintain such performance, reinforcement of the carcass, which is a skeleton of the tire, is essential.

Since tires support excessive loads and burdens from the vehicle against air pressure, stabilization of the carcass layer is known as an essential condition for long-term durability. The carcass part uses a backing layer to distinguish it from the inner liner part which is in direct contact with air pressure. The backing layer suppresses moisture transmitted from the inner liner layer and additionally supplements the adhesion between the reinforcing cord and the rubber. Function. In general, in the case of long-run tires, since the backup layer is first destroyed, the carcass layer is gradually destroyed. Thus, in the present invention, a rubber composition for a tire that can be used for the backup layer to improve fatigue resistance of the tire. To provide.

The present invention is to provide a rubber composition for a tire that can improve the fatigue resistance by improving the dispersibility of the reinforcing filler in the known rubber composition for the tire, including zinc acetate (Zinc acetate).

Another object of the present invention is to provide a tire having improved fatigue resistance by including a rubber made of the rubber composition in the tire.

In another aspect, the present invention is to provide a tire with improved durability and at the same time protect the carcass by applying a rubber compound consisting of the rubber composition to the backing layer of the tire.

In order to achieve the above-mentioned object, the present invention, in a known rubber composition for tires, may include 1.5 to 2.5 phr of zinc acetate (Zn (CH ₃ COO) ₂ · 2H ₂ O) with respect to 100 phr of raw rubber.

In the present invention, when the zinc acetate is less than 1.5 phr, the dispersibility of the reinforcing filler is low, and the fatigue resistance of the rubber is reduced. When the zinc acetate is used more than 2.5 phr, the dispersibility of the reinforcing filler is not significantly improved. Fatigue resistance is not improved. Therefore, it is preferable to include 1.5 to 2.5 phr of zinc acetate (Zn (CH ₃ COO) ₂ · 2H ₂ O) with respect to 100 phr of raw rubber in the present invention.

Meanwhile, in the present invention, the reinforcing filler may be used alone or in combination of two to 57 to 60 phr of carbon black and silica, which are used as reinforcing fillers in a rubber composition for a conventional tire, for 100 phr of raw rubber. When using a mixture of carbon black and silica, these mixing ratios may be used by mixing in a ratio of 1: 9 to 9: 1.

The rubber composition of the present invention is a vulcanizing agent (80% -CRYSTEX) 3.5 to 3.75 phr and vulcanization accelerator 0.7 with respect to 100 phr of raw rubber to improve the fatigue resistance of the rubber compound by producing a large amount of mono-sulfide and die-sulfide during vulcanization. -0.9 phr can be used.

In the present invention, the reinforcing filler, sulfur, and vulcanization accelerator are applied to various contents in order to obtain a rubber composition having improved fatigue resistance by improving dispersibility of the reinforcing filler while maintaining an appropriate modulus. Rubber species can be obtained that meet the purpose. Therefore, in the present invention, reinforcing fillers, sulfur, and vulcanization accelerators may be used within the above-mentioned numerical range.

In the present invention, the raw material rubber can be used as long as it can be used as the raw material rubber of the conventional rubber composition for tires. As an example of such raw rubber, in the present invention, synthetic rubber such as natural rubber, styrene butadiene rubber, butadiene rubber, styrene butadiene rubber containing isoprene, styrene butadiene rubber containing nitrile, and neoprene rubber may be used alone or two or more of them. Mixed rubbers in which synthetic rubbers are mixed in the same ratio may be used. In addition, it is possible to use a mixture of the natural rubber and synthetic rubber mixed in a ratio of 1: 9 to 9: 1.

The present invention, in addition to the above-mentioned raw rubber, zinc acetate, reinforcing fillers, vulcanizing agents and vulcanization accelerators, various additives such as activators, anti-aging agents, process oils used in conventional rubber compositions for tires may be selected as necessary. It can be used as a content. However, these are general components used in a rubber composition for a tire and are not essential components of the present invention.

On the other hand, the present invention includes a tire containing a rubber made of the rubber composition for tires, and more preferably a tire which can use the rubber made of the rubber composition for tires as a backing layer of the carcass portion. In this case, the tire includes any one selected from tires for automobiles, tires for trucks, and tires for buses.

Hereinafter, the present invention will be described by the following comparative examples, examples and test examples. However, these are not limited to the scope of the present invention by these as an embodiment of the present invention.

Comparative Example

As shown in Table 1 below, as a raw material rubber, 100 phr of natural rubber (SMR-20) was zincized 7 phr, carbon black (N330) 55 phr, stearic acid 0.8 phr, antioxidant (Kumanox-RD) 2 phr, antioxidant (Kumanox-13) 2 phr , 0.25 phr anti-aging agent (Kumanox-3C), 0.4 phr MANOBOND, 2.0 phr resorcinol resin (B18S), 3.7 phr MOR 0.8 phr, melamine resin (Cyrez 964) 0.2 phr, vulcanizing agent (PVI) 0.2 phr, vulcanizing agent (SULFASAN) ) 1.0 phr, vulcanizing agent (80% -CRYSTEX) 4.7 phr was placed in a Banbury mixer and vulcanized at 145 ° C. for 35 minutes to prepare a rubber.

The natural rubber (SMR-20) used as the raw material rubber is 1.5 parts by weight of 2,2-dibenzaminodiphenyldisulfide based on 100 phr of natural rubber, mixed with natural rubber for 2 to 5 minutes, and then dumped at 140 to 150 ° C. The Soviet Union was used.

<Example 1>

As a raw material rubber, zincized 5phr, zinc acetate 2.0phr, carbon black (N351) 47phr, silica 12phr, stearic acid 1.0phr, anti-aging agent (Kumanox-RD) 3.5phr with respect to 100phr of natural rubber (SMR-20) as raw rubber , Antioxidant (Kumanox-13) 1.0phr, Antioxidant (Kumanox-3C) 0.25phr, Cobalt Boroacylate (MANOBOND) 0.4phr, Resorcinol Resin (B18S) 1.5phr, Melamine Resin (Cyrez 964) 3.2 phr, vulcanization accelerator (Nt-butylbenzothiazole-Z-sulfenamide, NS) 0.7 phr, vulcanization delaying agent (PVI) 0.2 phr, vulcanizing agent (80% -CRYSTEX) 3.75 phr in banbury mixer for 35 minutes To prepare a rubber.

The natural rubber (SMR-20) used as the raw material rubber is 1.5 parts by weight of 2,2-dibenzaminodiphenyldisulfide based on 100 phr of natural rubber, mixed with natural rubber for 2 to 5 minutes, and then dumped at 140 to 150 ° C. The Soviet Union was used.

<Example 2>

As a raw material rubber, as a raw material rubber, 100 phr of zinc (SMR-20), 100 phr of zinc, 2.0 phr of zinc acetate, 58 phr of carbon black (N330), 1.5 phr of stearic acid, 2 phr of antioxidant (Kumanox-RD), anti-aging agent ( Kumanox-13) 1.0phr, MANOBOND 0.4phr, resorcinol resin (B18S) 1.0phr, melamine resin (Cyrez 964) 1.8phr, vulcanization accelerator (N-dicyclohexyl-2-benzothiazolsulfen amide, DZ) 0.9phr, vulcanization delay agent (PVI) 0.1 phr, 3.5 phr of vulcanizing agent (80% -CRYSTEX) was placed in a Banbury mixer and vulcanized at 145 ° C. for 35 minutes to prepare a rubber.

The natural rubber (SMR-20) used as the raw material rubber is 1.5 parts by weight of 2,2-dibenzaminodiphenyldisulfide based on 100 phr of natural rubber, mixed with natural rubber for 2 to 5 minutes, and then dumped at 140 to 150 ° C. The Soviet Union was used.

Table 1. Comparative Examples and Examples Rubber Composition

Item Comparative example Example 1 Example 2 SMR-20 100 100 100 Zincification 7.0 7.0 7.0 Zinc acetate - 2.0 2.0 N330 55 - 58 N351 - 47 - Silica - 12 - Stearic acid 0.8 1.0 1.5 Kumanox-RD 2.0 3.5 2.0 Kumanox-13 2.0 1.0 1.0 Kumanox-3C 0.25 0.25 - MANOBOND 0.4 0.4 0.4 B-18-S 2.0 1.5 1.0 CYREZ964 3.7 3.2 1.8 MOR * 0.8 - - NS - 0.7 - DZ - - 0.9 Vulcanization delay agent 0.2 0.2 0.1 80% -CRYSTEX 4.7 3.75 3.5 SULFASAN 1.0 - -

* MOR: N-oxydiethylene-2-benzothiazole-sulfenamide-2- (Morpholinothio) benzothiazol

Test Example 1 Measurement of Properties

Physical properties such as Mooney viscosity, scorch time, proper curing time, hardness, 100% modulus, 300% modulus, tensile strength and elongation at cut are measured according to ASTM-related regulations for the rubbers of Comparative Examples and Examples. Table 2 is summarized.

Table 2. Comparative Examples and Examples Rubber Properties

Item Comparative example 1 to implementation Example 2 Mooney viscosity (100 ℃) 71.02 89.15 71.50 Scorch Time (T5) 18.0 25.33 25.13 Proper Curing Time (min) 24.15 28.31 25.69 Hardness 73 70 71 100% modulus 50 35 40 300% modulus 179 146 165 The tensile strength 251 217 270 Elongation at Cutting 430 447 465

Test Example 2 Fatigue Resistance Measurement

Fatigue resistance properties of the rubbers of the Comparative Examples and Examples were measured, and the results are shown in Table 3 below.

Table 3. Fatigue Resistance Characteristics

Item Comparative example Example 1 Example 2 Horizontal breakage amount (mm) 7.25 4.41 2.51 Vertical destruction amount (mm) 24.0 5.1 4.5

* Fatigue resistance shows the amount of crack growth after 30,000 repeated bendings of rubber specimens using DIMATIA tester. The smaller the value, the better fatigue resistance.

As shown in the physical properties of Table 2, the rubber compound made of the rubber composition of the present invention can be seen that has a physical property equivalent or more compared with the rubber compound made of a conventional rubber composition. On the other hand, it can be seen that the rubber compound made of the rubber composition of the present invention, as shown in Table 3, has significantly increased fatigue resistance compared to the rubber compound made of the conventional rubber composition.

As a result, the present invention can provide a rubber composition with improved fatigue resistance while having the same level of physical properties as compared with the conventional rubber composition.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the present invention described in the claims below. It will be appreciated that it can be changed.

Claims (3)

In the rubber composition for tires, A rubber composition for tires, comprising 1.5 to 2.5 phr of zinc acetate per 100 phr of raw rubber. The method of claim 1, wherein the raw material rubber further comprises at least one reinforcing filler 57 to 60 phr selected from carbon black and silica, vulcanization accelerator 0.7 to 0.9 phr, and 80% CRYSTEX 3.5 to 3.75 phr for 100 phr of raw rubber. Rubber composition for tires. A tire comprising a rubber comprising the rubber composition of claim 1.