KR100746335B1 - Tire inner liner rubber composition - Google Patents

Abstract

Provided is a tire inner liner rubber composition which is improved in air penetration, crack resistance characteristics and fatigue resistance characteristics. A tire inner liner rubber composition comprises 100 parts by weight of a rubber material which is at least one selected from butyl rubber and halobutyl rubber, or comprises 80-95 parts by weight of at least one rubber selected from butyl rubber and halobutyl rubber and 5-20 parts by weight of a natural rubber; 5-50 parts by weight of a butyl rubber composition which comprises 30-70 wt% of butyl rubber, 20-50 wt% of carbon black and 10-20 wt% of a plasticizer; and 55-85 parts by weight of the carbon black having an iodine adsorption number of 20-50 mg/g, a DBP absorption of 70-90 mL/100 g and a particle size of 61-100 nm.

Description

Tire inner liner rubber composition

The present invention relates to a tire inner liner rubber composition, and more particularly, to a conventional tire inner liner rubber composition, by applying a butyl rubber composition composed of butyl rubber, carbon black, and a plasticizer and carbon black having a large particle size. The present invention relates to a tire inner liner rubber composition having improved crack characteristics and fatigue resistance.

In recent years, with the continuous development of industrial technology, automobile manufacturers have also improved their technological capabilities to improve the performance of vehicles, and as road conditions improve, the vehicle's running speed gradually increases, and the severity applied to tires as the vehicle's performance improves. Is gradually increasing. Accordingly, many studies have been conducted by tire manufacturers to improve the air permeability and fatigue resistance of the inner liner in order to maintain excellent long-distance driving wear performance even in harsh conditions.

The rubber composition for the inner liner of pneumatic tires uses butyl rubber as raw material rubber or mixed rubber of a large amount of butyl rubber with a small amount of natural rubber and / or synthetic rubber as a raw material rubber. Although research on improving air permeability of tire inner liner has been conducted, the results are still insufficient.

However, various studies have been continuously conducted to improve the air permeability of the inner liner rubber composition.

As an example of the prior art related to the present invention, the Republic of Korea Patent No. 10-0253122 improves the air permeability of the inner liner rubber composition by applying a thermal carbon black (butyl carbon) and thermal carbon black having a small surface area and poor structure development There is this.

In addition, Korean Patent No. 10-0227568 discloses isobutylene-methylcyclopentadiene-cyclopentadiene rubber having a number average molecular weight of 100,000 or more and an unsaturation of 2 to 20 mol% in the inner liner rubber composition. There is a content of a tire inner liner rubber composition using 100 parts by weight.

However, the prior arts, in the conventional tire inner liner rubber composition, apply butyl rubber composition consisting of butyl rubber, carbon black and plasticizer and carbon black having a large particle diameter to improve air permeability, crack resistance, heat aging resistance and processing stability. The present invention showing the improved tire inner liner rubber composition differs from the technical configuration.

The present invention is a tire inner liner in the conventional tire inner liner rubber composition by applying a butyl rubber composition consisting of butyl rubber, carbon black and plasticizer and carbon black having a large particle diameter to improve air permeability, crack resistance and fatigue resistance. To provide a rubber composition.

The present invention includes a tire comprising a rubber made of the above-mentioned tire inner liner rubber composition.

Tire inner liner rubber composition of the present invention for achieving the above-mentioned object is 5 to 50 parts by weight of butyl rubber composition, 55 to 85 parts by weight of carbon black with respect to 100 parts by weight of the raw material rubber in the conventional tire inner liner rubber composition Include.

In the present invention, the raw material rubber may be any one or more selected from butyl rubber and halobutyl rubber. Further, in addition to any one or more selected from the above butyl rubber and halobutyl rubber, a small amount of natural rubber may be included in the raw material rubber. When 100 parts by weight of raw rubber is applied as an example of including natural rubber as raw rubber, 80 to 95 parts by weight of at least one rubber selected from butyl rubber and halobutyl rubber and 5 to 20 parts by weight of natural rubber can be applied. have.

The halobutyl rubber may be any one or more selected from chlorobutyl rubber and bromobutyl rubber.

Inner liner rubber composition in the present invention may be applied to the butyl rubber composition in the above-mentioned content in order to improve the air permeability at the same time as the filler.

In the present invention, the butyl rubber composition is applied to various components and contents, and the innerliner rubber composition serves as a filler and the butyl rubber composition is 30 to 70% by weight of butyl rubber and 20 to carbon black to improve air permeability. What consists of 50 weight% and 10-20 weight% of plasticizers can be used.

The butyl rubber in the butyl rubber composition may be applied to any one or more selected from butyl rubber, chlorobutyl rubber, bromobutyl rubber, more preferably the same components as the butyl rubber of the raw material rubber.

In the butyl rubber composition, the carbon black may have the same characteristics as the carbon black used as the reinforcing filler in the inner liner rubber composition, so that the butyl rubber composition may serve as a filler. For example, in the butyl rubber composition, carbon black may have a iodine adsorption of 20 to 50 mg / g, a DBP adsorption of 70 to 90 ml / 100 g, and a particle diameter of 61 to 100 nm.

The plasticizer in the butyl rubber composition may be used as long as it can be applied as a plasticizer in the tire rubber field. As an example of such a plasticizer, any one or more selected from dioctyl phthalate (DOP), dioctyl adipate (DOA), tricresyl phosphorate (TCP), and KOSYN KHS (Kumho Petrochemical) can be used.

The butyl rubber composition is an example of a kind of master batch, which is stirred by adding and dispersing butyl rubber, carbon black, and plasticizer in a reactor, blended at 110 to 140 ° C., dried, and then ground. Can be.

Carbon black used as a reinforcing filler in the present invention may be applied to a large particle size to improve the fatigue resistance and crack resistance of the tire inner liner rubber composition. In the present invention, as one example of such carbon black, iodine adsorption of 20 to 50 mg / g, DBP adsorption of 70 to 90 ml / 100 g, and particle diameter of 61 to 100 nm can be used.

In the present invention, the tire inner liner rubber composition is applied by various compositions and contents. In order to achieve the object of the present invention, it is preferable to apply the tire inner liner rubber composition to the above-described content of butyl rubber composition and carbon black.

The present invention, in addition to the above-mentioned raw rubber, butyl rubber composition, carbon black, various additives such as reinforcing fillers, activators, anti-aging agents, process oils, vulcanizing agents and vulcanization accelerators used in conventional tire inner liner rubber compositions as needed It can be used at a predetermined content by selecting an enemy. However, these are general components used in the conventional tire inner liner rubber composition 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 tire inner liner rubber composition. In this case, preferably, a tire containing a rubber made of the tire inner liner rubber composition of the present invention as an inner liner is included.

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 1

60 parts by weight of carbon black (1), 10 parts by weight of process oil, 3 parts by weight of zinc oxide, and 2 parts by weight of stearic acid were placed in a Banbury mixer as a raw material rubber, based on 100 parts by weight of bromobutyl rubber. Blending for 30 minutes gave a rubber blend. Then, the mixture was left at room temperature for 24 hours, and 1 part by weight of sulfur and 1 part by weight of a vulcanization accelerator (N-cyclohexyl-2-benzothiazolsulfen amide, CZ) were added to the rubber compound and vulcanized at 150 ° C. for 20 minutes to prepare a rubber specimen. .

In the carbon black (1), iodine adsorption was used 36mg / g, DBP adsorption 91ml / 100g, the particle size of 50nm was used.

Comparative Example 2

A rubber specimen was prepared in the same manner as in Comparative Example 1 except that 65 parts by weight of carbon black (2) was used based on 100 parts by weight of the raw material rubber consisting of 90 parts by weight of bromobutyl rubber and 10 parts by weight of natural rubber.

In the carbon black (2), iodine adsorption was used 33mg / g, DBP adsorption 72ml / 100g, 90nm particle size was used.

Example 1

5 parts by weight of butyl rubber composition, 55 parts by weight of carbon black (2), 10 parts by weight of process oil, 3 parts by weight of zinc oxide, and 2 parts by weight of stearic acid, as a raw material rubber, based on 100 parts by weight of bromobutyl rubber. The mixture was placed in a Banbury mixer and blended at 140 ° C. for 30 minutes to obtain a rubber compound. Then, the mixture was allowed to stand at room temperature for 24 hours, 1 part by weight of sulfur and 1 part by weight of a vulcanization accelerator (CZ) were added to the rubber mixture, and vulcanized at 150 ° C. for 20 minutes to prepare a rubber specimen.

In the above butyl rubber composition, 50% by weight of butyl rubber, 38% by weight of carbon black (2), and 12% by weight of dioctylphthalate (DOP) as a plasticizer are added and dispersed in a dispersed state, the mixture is mixed at 125 ° C, and dried. It was used to make a grinding and grinding process.

In the carbon black (2), iodine adsorption was used 33mg / g, DBP adsorption 72ml / 100g, 90nm particle size was used.

Example 2

A rubber specimen was prepared in the same manner as in Example 1, except that 10 parts by weight of butyl rubber composition and 65 parts by weight of carbon black (2) were used.

Example 3

A rubber specimen was prepared in the same manner as in Example 1 except that 20 parts by weight of butyl rubber composition and 75 parts by weight of carbon black (2) were used.

Example 4

A rubber specimen was prepared in the same manner as in Example 1, except that 50 parts by weight of butyl rubber composition and 85 parts by weight of carbon black (2) were used.

Table 1. COMPARATIVE EXAMPLES AND EXAMPLES Rubber Compositions

Item Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Bromobutyl Rubber 100 90 100 100 100 100 Natural rubber - 10 - - - - Butyl Rubber Composition - - 5 10 20 50 Carbon black (1) 60 - - - - - Carbon black (2) - 65 55 65 75 85 Process oil 10 10 10 10 10 10 Zinc oxide 3 3 3 3 3 3 Stearic acid 2 2 2 2 2 2 brimstone One One One One One One Vulcanization accelerator One One One One One One

<Test Example>

The rubber specimens of Comparative Examples and Examples were prepared according to ASTM-related regulations, such as fairness (Mooney viscosity (100 ° C.), scorch time, vulcanization time), tensile properties (hardness, 300% modulus, tensile strength, elongation), air permeability, Physical properties for FTF (Fatigue-to-Failure) and crack growth were measured and the results are summarized in Table 2 below.

Table 2. Comparative Examples and Examples Properties of Rubber Specimens

Item Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Fairness Mooney viscosity (100 ℃) 50 52 49 50 50.5 53 Scotch time (t5) 30.2 29.5 32.5 31.2 30.6 29.8 Rush time (t90) 37.5 34.3 38.5 37.4 36.5 34.9 Tensile Properties Shore A 52.0 54.0 52.0 52.0 52.5 53.0 300% modulus (kg / cm ² ) 30.2 23.6 30.5 31.5 32.6 33.5 Tensile Strength (kg / cm ² ) 91.2 85.6 91.6 92.5 93.5 96.0 % Elongation 860.6 910.0 880.5 856.6 850.6 849.5 Air Permeability * 2.6 3.4 2.4 2.1 1.9 1.4 F.T.F. * 420 385 435 442 445 437 Crack Growth * Before aging 3.4 6.2 3.5 3.3 3.1 3.0 After aging 5.1 11.0 4.9 4.5 3.9 3.9

* Air permeability coefficient: To measure the air permeability of the vulcanized innerliner rubber, measure the amount of air moved through the thickness of the specimen per unit area of the specimen for one hour with a difference of one air pressure on both sides of the rubber specimen. As a value, the lower the value, the lower the air movement value, which means that the air permeability is excellent.

* FFT (Fatigue-to-Failure): A test method for measuring fatigue resistance of inner liner rubber, which was tested according to ASTM D430-73, and the fatigue cycle until the inner liner rubber specimen was cut through continuous repeated fatigue. The higher the value, the better the resistance to fatigue.

* Crack growth: A measure of crack growth length before and after aging (aging at 105 ° C. for 3 days). The higher the value, the greater the crack growth, which impairs characteristics.

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

In the workability and tensile properties of Table 2, the rubber sample of the present invention has a physical property equal to or higher than the comparative example of the conventional rubber sample in terms of workability and tensile properties.

On the other hand, the physical properties of the air permeability coefficient, F.T.F. (Fatigue-to-Failure) and crack growth, it can be seen that the rubber sample of the present invention is superior to the rubber sample of the comparative example showing a conventional rubber composition.

Claims (3)

In the tire inner liner rubber composition, 80 to 95 parts by weight of any one or more rubbers selected from butyl rubber and halobutyl rubber, or 100 parts by weight of the raw material rubber comprising 80 to 95 parts by weight of any one or more rubbers selected from butyl rubber and halobutyl rubber. 5 to 50 parts by weight of butyl rubber composition consisting of 30 to 70% by weight of butyl rubber, 20 to 50% by weight of carbon black, 10 to 20% by weight of plasticizer, 20 to 50 mg / g of iodine adsorption, 70 to 90 ml / 100 g of DBP adsorption, particle diameter A tire inner liner rubber composition comprising 55 to 85 parts by weight of carbon black having 61 to 100 nm. delete delete