KR20170000982A - Tire carcass and the manufacture method thereof - Google Patents

Abstract

The present invention relates to a tire carcass and a method for producing the same, wherein in a two-layered tire carcass, a rubber composition for topping carcass comprising a butyl rubber and an epoxidized natural rubber is topped on a lower layer of a carcass cord, A tire carcass for topical carcass topping comprising a butadiene rubber is topped on top of a carcass cord and includes a carcass cord interposed between the bottom and top layers to provide a tire carcass with excellent air permeability and adhesion, It is possible to provide a lightweight tire.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a tire carcass,

The present invention relates to a tire carcass having improved air permeability and excellent adhesion, and a method for producing the same.

The Inner Liner of the tire is located at the innermost part of the structure of the tire, so that it does not leak air from the tire and the rim when it is attached to the vehicle, and maintains the air pressure in the tire. Accordingly, the air permeability of the rubber composition for a tire inner liner is required. For this purpose, butyl rubber is generally used. Since the butyl rubber prevents the air from permeating into the tire, the inner air permeability of the inner liner is directly related to the tire durability.

Since the adhesion of the butyl rubber to the diene rubber used for carcass cord and topping rubber is unfavorable, a diene-based secondary inner liner made of natural rubber is introduced between the butyl-based innerliner and the carcass layer, Structure.

The two-layer inner liner structure prevents the problem that adhesion between the butyl rubber layer and the carcass layer may be deteriorated as described above, and prevents the deterioration of durability that may occur when the butyl-based innerliner penetrates into the carcass Can play a role.

Specifically, since the diene rubber is present inside the butyl rubber, even if the rubber comes in contact with the carcass cord, the same diene rubber acts to prevent the durability of the rubber rubber from being deteriorated without significantly decreasing the adhesive force. For this two-layer inner liner structure, equipment and rolling step for adhesion of a butyl-based inner liner and a natural rubber-based (NR-based) inner liner are required prior to molding.

On the other hand, recently, interest in the environment has increased, and there is a growing demand for improving the fuel-efficiency performance of the tire in the automobile industry. For this purpose, the viscoelastic property of rubber is improved mainly for the tread, and it contributes to the fuel consumption by reducing the weight of the tread. However, the relative inner liner has a limitation other than contributing to the weight reduction by reducing the thickness due to the air permeability and the adhesion with the cord In fact.

A method of contributing to the weight reduction of a tire while studying the simplification of the tire manufacturing process by eliminating the steps and facilities for making the inner liner structure of two layers by introducing the butyl rubber of the inner liner into the carcass topping rubber has been studied, Adhesion to the cord may be deteriorated. When butyl rubber is introduced into the topping rubber, the thickness of the inner liner structure may be thinner than that of the conventional inner liner structure, which may result in deterioration of air permeability.

An object of the present invention is to provide a tire carcass with improved air permeability and excellent adhesion.

Another object of the present invention is to provide a method of manufacturing a tire carcass with improved air permeability and excellent adhesion.

In order to achieve the above object, the present invention provides a rubber composition for a carcass lower layer topping comprising a carcass cord, a butyl rubber and an epoxidized natural rubber, comprising a lower layer topping layer topped with a lower layer of the carcass cord, and a styrene butadiene rubber Wherein the rubber composition for carcass upper layer topping comprises an upper layer topping layer topped on top of the carcass cord.

The rubber composition for a carcass lower layer topping comprising the butyl rubber and the epoxidized natural rubber is a rubber composition comprising 65 to 85 parts by weight of a butyl rubber, 10 to 30 parts by weight of a natural rubber and 10 to 20 parts by weight of an epoxidized natural rubber, 45 to 65 parts by weight of carbon black, 0.5 to 2.0 parts by weight of a vulcanization activator, 0.5 to 1.5 parts by weight of a vulcanization accelerator, and 0.5 to 1.5 parts by weight of sulfur.

The butyl rubber may be any one selected from the group consisting of butyl rubber (IIR), butyl rubber of bromine (Br-IIR), halogenated butyl rubber of chlorinated butyl rubber (Cl-IIR), and combinations thereof.

The epoxidized natural rubber may contain 10 to 50% by weight of an epoxy group introduced into the natural rubber.

The rubber composition for a top layer topcoat tire carcass comprising styrene butadiene rubber may comprise 60 to 80 parts by weight of natural rubber and 20 to 40 parts by weight of styrene butadiene rubber.

The present invention also relates to a rubber composition for lower layer topping which comprises a rubber composition for a lower layer topping using a rubber composition for a carcass lower layer topping comprising a butyl rubber and an epoxidized natural rubber and a rubber composition for upper layer topping comprising a styrene butadiene rubber, Preparing a rolling machine composed of rolls 1 to 4; injecting the rubber for upper layer topping between rolls 1 and 2; feeding the upper layer topping rubber between the rolls 3 and 4; And passing a carcass cord between the second roll and the third roll. The present invention also provides a method of manufacturing a tire carcass.

The present invention also provides a tire manufactured using the tire carcass according to the present invention.

The tire may not include an inner liner.

The present invention can provide a tire carcass with excellent air permeability and adhesion.

It is possible to omit a separate inner liner rubber layer using the tire carcass, thereby contributing to the weight reduction of the tire.

The tire according to the present invention is lightweight and can improve the low fuel consumption and the environmental friendliness.

The method of manufacturing a tire carcass according to the present invention can simplify the manufacturing steps and reduce manufacturing cost and time.

1 is a schematic view showing a cross section of a tire carcass according to an embodiment of the present invention.
2 is a schematic view showing a method of manufacturing a tire carcass according to another embodiment of the present invention.

Hereinafter, the present invention will be described in more detail.

1 is a schematic view showing a cross section of a tire carcass 100 according to an embodiment of the present invention. FIG. 1 is an illustration for illustrating the present invention, but the present invention is not limited thereto.

1, a tire carcass 100 according to the present invention includes a carcass cord 30, a lower layer topping layer 10 topped on the lower layer of the carcass cord 30, And an upper layer topping layer 20 topped on the upper layer.

The tire carcass 100 is composed of two layers, and a rubber composition for carcass lower layer topping comprising butyl rubber and epoxidized natural rubber is topped to the lower layer portion of the carcass cord 30, and a rubber composition containing styrene butadiene rubber A carcass cord 30 is sandwiched between a carcass lower layer topping layer 10 and a carcass upper layer topping layer 20.

(One) Kakas  substratum Topping part (10)

A rubber composition for a carcass lower layer topping comprising butyl rubber and epoxidized natural rubber comprises 100 parts by weight of a starting rubber comprising 65 to 85 parts by weight of butyl rubber, 10 to 30 parts by weight of natural rubber and 10 to 20 parts by weight of epoxidized natural rubber 45 to 65 parts by weight of carbon black, 0.5 to 2.0 parts by weight of a vulcanization activator, 0.5 to 1.5 parts by weight of a vulcanization accelerator, and 0.5 to 1.5 parts by weight of sulfur.

The butyl rubber is a copolymer of isobutylene and isoprene, which is also referred to as isobutylene-isoprene rubber. Specifically, the butyl rubber may be any one selected from the group consisting of butyl rubber (IIR), brominated butyl rubber (Br-IIR), halogenated butyl rubber of chlorinated butyl rubber (Cl-IIR), and combinations thereof.

The natural rubber may be any known natural rubber, and the origin of the natural rubber is not limited. The natural rubber includes cis-1,4-polyisoprene as a main component, but may also include trans-1,4-polyisoprene depending on required characteristics. Therefore, in addition to natural rubber containing cis-1,4-polyisoprene as a main component, natural rubber including trans-1,4-isoprene as a main component, such as balata, Rubber may also be included.

If the natural rubber is contained in an amount of more than 30 parts by weight, the air permeability becomes worse. If the natural rubber is included in an amount less than 10 parts by weight, the adhesive strength is lowered.

The epoxidized natural rubber (ENR) may contain 10 to 50% by weight of an epoxy group introduced into a natural rubber.

If the amount of the epoxy group is less than 10% by weight, the air permeation may be disadvantageously deteriorated. If the amount is more than 50% by weight, adherence is decreased and workability is deteriorated.

In the present invention, since the butyl rubber used as the inner liner rubber composition at the time of tire topping is mixed with the epoxidized natural rubber, the molding time can be shortened by not using a separate inner liner attaching step, The inner liner can be omitted, which can contribute to tire weight reduction. The use of epoxidized natural rubber, which is more air permeable than natural rubber, can overcome the disadvantage that the air permeability becomes disadvantageous when an excessive amount of natural rubber is used to increase the adhesive strength.

The rubber composition for topping carcass comprising the butyl rubber and the epoxidized natural rubber optionally further comprises various additives such as additional vulcanizing agents, vulcanization accelerators, vulcanization accelerators, fillers, coupling agents, antioxidants or pressure-sensitive adhesives . Any of the various additives may be used as long as they are commonly used in the field to which the present invention belongs. The content of these additives is not particularly limited as long as it depends on the compounding ratio used in a rubber composition for a tire carcass.

The rubber composition for topping carcass comprising the butyl rubber and the epoxidized natural rubber may further comprise a filler. The filler may be any one selected from the group consisting of carbon black, silica, calcium carbonate, clay (hydrated aluminum silicate), aluminum hydroxide, lignin, silicate, talc, and combinations thereof, preferably carbon black.

The carbon black may have a nitrogen surface area per gram (N ² SA) of 100 to 400 m ² / g and a hydrogen ion index of 4 to 12. If the nitrogen adsorption specific surface area of the carbon black exceeds 400 m ² / g, the workability of the rubber composition for a tire may be deteriorated. If it is less than 100 m ² / g, the reinforcing performance by the carbon black as a filler may be deteriorated. If the DBP oil absorption of the carbon black exceeds 180 cc / 100 g, the workability of the rubber composition may be deteriorated. If it is less than 60 cc / 100 g, the reinforcing performance by carbon black as a filler may be deteriorated.

The carbon black used in the present invention is preferably a product having a particle size distribution D50 / M of less than 0.7. When the particle size distribution D50 / M is 0.7 or more, the particle size distribution is large and the hardness may be lowered.

Examples of the carbon black include furnace black (furnace carbon black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF and ECF; Acetylene black (acetylene carbon black); Thermal blacks such as FT and MT (thermal carbon black); Channel blacks such as EPC, MPC and CC (channel carbon black); Graphite and the like. These may be used alone or in combination of two or more. Examples of the carbon black include N110, N121, N134, N220, N231, N234, N242, N293, N299, S315, N326, N330, N332, N339, N343, N347, N351, N358, N375, N539, , N630, N642, N650, N683, N754, N762, N765, N774, N787, N907, N908, N990 or N991. Most preferably, carbon black of GPF grade can be used.

The content of the carbon black is preferably 45 to 65 parts by weight based on 100 parts by weight of the starting rubber.

If the content of the carbon black is less than 45 parts by weight, the reinforcing effect by the added carbon black can not be sufficiently obtained. If the content of the carbon black exceeds 65 parts by weight, the dispersibility and the physical properties may deteriorate due to poor mixing in the rubber.

The rubber composition for carcass lower layer topping comprising the butyl rubber and the epoxidized natural rubber may further comprise a vulcanization accelerator.

The vulcanization accelerator refers to an accelerator that promotes the vulcanization rate or accelerates the retardation in the initial vulcanization step.

Examples of the vulcanization accelerator include sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamate, aldehyde-amine, aldehyde-ammonia, imidazoline, Or a combination thereof.

Examples of the sulfenamide type vulcanization accelerator include N-cyclohexyl-2-benzothiazyl sulfenamide (CBS), N-tert-butyl-2-benzothiazyl sulfenamide (TBBS), N, N-dicyclohexyl -2-benzothiazyl sulfenamide, N-oxydiethylene-2-benzothiazyl sulfenamide, N, N-diisopropyl-2-benzothiazole sulfenamide, and combinations thereof Based compound can be used.

Examples of the thiol-based vulcanization accelerator include 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (MBTS), sodium salt of 2-mercaptobenzothiazole, zinc salt of 2-mercaptobenzothiazole , A copper salt of 2-mercaptobenzothiazole, a cyclohexylamine salt of 2-mercaptobenzothiazole, 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- Ethyl 4-morpholinothio) benzothiazole, and combinations thereof. The thiazole-based compound may be used alone or in combination of two or more thereof.

Examples of the thiuram-based vulcanization accelerator include tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide, tetramethylthiuram monosulfide, dipentamethylthiuram disulfide, dipentamethylthiuram monosulfide, dipentamethylene Any one of thiuram-based compounds selected from the group consisting of thiuram tetrasulfide, dipentamethylenethiuram hexasulfide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide, and combinations thereof can be used.

Examples of the thiourea vulcanization accelerator include thiourea compounds selected from the group consisting of thiacarbamide, diethyl thiourea, dibutyl thiourea, trimethyl thiourea, diorthotolyl thiourea, and combinations thereof. Compounds may be used.

Examples of the guanidine-based vulcanization accelerator include guanidine-based compounds selected from the group consisting of diphenyl guanidine, diorthotolyl guanidine, triphenyl guanidine, orthotolyl biguanide, diphenyl guanidine phthalate, and combinations thereof .

Examples of the dithiocarbamate-based vulcanization accelerator include zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, Zinc dibutyldithiocarbamate, zinc diamidithiocarbamate, zinc dipropyldithiocarbamate, complexation of zinc with piperidinedithiocarbamate and piperidine, zinc hexadecylisopropyldithiocarbamate, octadecyl Isopropyl dithiocarbamic acid zinc zinc dibenzyldithiocarbamate, sodium diethyldithiocarbamate, penta methylenedithiocarbamate, sodium selenium dimethyldithiocarbamate, diethyldithiocarbamate, sodium diethyldithiocarbamate, Cadmium dithiocarbamate, and combinations thereof. The dithiocarbamic acid-based compound may be used alone or in combination of two or more thereof.

Examples of the aldehyde-amine-based or aldehyde-ammonia-based vulcanization accelerator include aldehyde selected from the group consisting of acetaldehyde-aniline reactant, butylaldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde- -Amine-based or aldehyde-ammonia-based compounds may be used.

As the imidazoline-based vulcanization accelerator, for example, an imidazoline-based compound such as 2-mercaptoimidazoline can be used. Examples of the xanthate vulcanization accelerator include xanthates such as zinc dibutylxanthogenate Compounds may be used.

The vulcanization accelerator may be included in an amount of 0.5 to 1.5 parts by weight with respect to 100 parts by weight of the raw rubber in order to maximize productivity improvement and rubber property improvement through vulcanization speed promotion.

The vulcanization accelerating assistant may be any one selected from the group consisting of an inorganic vulcanization accelerator aid, an organic vulcanization accelerator aid, and a combination thereof, which is used in combination with the vulcanization accelerator to complete the promoting effect thereof .

As the inorganic vulcanization accelerating aid, any one selected from the group consisting of zinc oxide (ZnO), zinc carbonate, magnesium oxide (MgO), lead oxide, potassium hydroxide and combinations thereof may be used have. As the organic vulcanization accelerating auxiliary, there may be selected from the group consisting of stearic acid, zinc stearate, palmitic acid, linoleic acid, oleic acid, lauric acid, dibutyl ammonium oleate, derivatives thereof, Can be used.

In particular, the zinc oxide and the stearic acid may be used together as the vulcanization accelerating assistant. In this case, the zinc oxide is dissolved in the stearic acid to form an effective complex with the vulcanization accelerator, Thereby facilitating the crosslinking reaction of the rubber.

When zinc oxide and stearic acid are used together, they may be used in an amount of 0.5 to 5 parts by weight and 0.5 to 1.5 parts by weight based on 100 parts by weight of the raw material rubber, respectively, in order to serve as a proper vulcanization accelerating auxiliary. If the content of the zinc oxide and the stearic acid is less than the above range, the vulcanization rate may be slow and the productivity may be deteriorated. If the content exceeds the above range, the scorch phenomenon may occur and the physical properties may be deteriorated.

The rubber composition for carcass topping (10) comprising the butyl rubber and the epoxidized natural rubber is obtained by replacing the softener with liquid rubber in whole or in part, and the softener is a petroleum oil. Accordingly, the petroleum-based oil may be included in an amount of 0 to 30 parts by weight based on 100 parts by weight of the raw material rubber. That is, the entire amount of the petroleum-based oil can be replaced with the liquid rubber, and when the content of the petroleum-based oil exceeds 30 parts by weight, the problem of low hardness may occur. When the liquid rubber is contained in the weight ratio, the rotational resistance performance can be maintained at the same level or higher while improving the braking performance on ice and snow road surface and wet road surface.

The petroleum-based oil may be any one selected from the group consisting of a paraffinic oil, a naphthenic oil, an aromatic oil, and a combination thereof, preferably an aromatic oil. In the case of using the petroleum oil as the aromatic system, it is more preferable that the compatibility with the rubber is optimal and it can be blended in a large amount.

In addition, the rubber composition 10 for carcass topping comprising the butyl rubber and the epoxidized natural rubber may contain a vulcanizing agent. As the vulcanizing agent, a sulfur vulcanizing agent can be preferably used. The sulfur vulcanizing agent is an inorganic vulcanizing agent such as powder sulfur (S), insoluble sulfur (S), precipitated sulfur (S), colloid sulfur, etc., tetramethylthiuram disulfide (TMTD) Organic vulcanizing agents such as tetraethyltriuram disulfide (TETD) and dithiodimorpholine can be used. As the sulfur vulcanizing agent, a vulcanizing agent which produces elemental sulfur or sulfur, for example, amine disulfide, polymer sulfur and the like can be used.

It is preferable that the vulcanizing agent is included in an amount of 5 to 10 parts by weight based on 100 parts by weight of the raw rubber, from the viewpoint that the raw rubber is less sensitive to heat and chemically stable.

(2) Kakas  Upper layer Topping layer (20)

The rubber composition for top layer topcoat of the tire carcass including the styrene butadiene rubber may include 60 to 80 parts by weight of natural rubber and 20 to 40 parts by weight of styrene butadiene rubber.

Wherein the styrene butadiene rubber has a styrene content of 22 to 25 wt%, a vinyl content of 15 to 18 wt%, a number average molecular weight (Mn) of 55,000 to 59,000, a weight average molecular weight (Mw) of 260,000 to 320,000, (MWD) of 3.8 to 4.2, a content of butadiene of 75 to 88 wt% or more, and a glass transition temperature (Tg) of -104 to -107 DEG C, and a high cis-butadiene rubber Lt; / RTI > The butadiene rubber may have a Mooney viscosity of 43 to 47 at 100 占 폚.

If the styrene-butadiene rubber is less than 20 parts by weight, the adhesive strength is deteriorated. If the styrene-butadiene rubber is more than 40 parts by weight, tensile properties may be deteriorated.

The rubber composition for top coat of a tire carcass top layer comprising the styrene butadiene rubber may further comprise various additives such as an additional vulcanizing agent, a vulcanization accelerator, a vulcanization accelerator, a filler, a coupling agent, an anti-aging agent, . Any of the various additives may be used as long as they are commonly used in the field to which the present invention belongs. The content of these additives is not particularly limited as long as it depends on the compounding ratio used in a rubber composition for a tire carcass. The additional additives of the rubber composition for upper layer carcass topping are the same as those described above.

(3) Kakas  Code 30

A carcass cord which is conventionally used can be used, and in detail, it may be formed of a plurality of steel cords.

(4) Tires Kakas  Manufacturing method

2 is a schematic view showing a method of manufacturing a tire carcass according to another embodiment of the present invention.

Referring to FIG. 2, the present invention provides a rubber composition for a lower layer topping using a rubber composition for a carcass lower layer topping comprising the butyl rubber and epoxidized natural rubber, and a top layer topcoat including the styrene butadiene rubber A step of preparing a rolling machine 200 composed of rolls 1 to 4, a step of preparing the upper layer topping rubber 201 between the rolls 1 and 2, , Feeding the lower layer topping rubber (101) between the third roll and the fourth roll, and passing the carcass cord (30) between the second roll and the third roll, And a manufacturing method thereof.

The rubber composition for a tire carcass according to the present invention is excellent in adhesion to carcass cords and has excellent air permeability, so that the inner liner layer can be omitted. This makes it possible to produce an eco-friendly tire that is lighter and has excellent durability.

The tires may be automobile tires, racing tires, airplane tires, agricultural tires, off-the-road tires, truck tires or bus tires. Further, the tire may be a radial tire or a bias tire, and preferably a radial tire.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[ Manufacturing example : Preparation of rubber composition]

Rubber compositions for tire carcass according to the following Examples and Comparative Examples were prepared using the compositions shown in Table 1 below. 2, a rubber composition for a lower layer topping is prepared by using a rubber composition for a carcass lower layer topping comprising butyl rubber and epoxidized natural rubber, and the above-mentioned styrene butadiene rubber is contained Preparing a carcass upper layer topping rubber by using a rubber composition for carcass upper layer topping, preparing a rolling machine 200 composed of rolls 1 to 4, A step of injecting the rubber 101 for the lower layer topping between the third roll and the fourth roll, a step of passing the carcass cord 30 between the second roll and the third roll, Respectively.

Content (parts by weight) Comparative Example Example One 2 3 One 2 3 Inner liner rubber layer (butyl rubber) has exist No inner liner rubber layer Rubber composition for carcass lower layer topping comprising butyl rubber and epoxidized natural rubber Butyl rubber (1) 70 80 70 70 70 Natural Rubber (2) 30 20 10 20 15 Epoxidized natural rubber (3) 0 0 20 10 15 Carbon black (4) 58 58 58 58 58 Vulcanizers (5) 1.1 1.1 1.1 1.1 1.1 Vulcanization accelerator 1 (6) 1.4 1.4 1.4 1.4 1.4 Sulfur (7) 0.6 0.6 0.6 0.6 0.6 Rubber composition for upper carcass top layer comprising styrene butadiene rubber Natural Rubber (2) 70 70 70 70 70 70 Styrene-butadiene rubbers (8) 30 30 30 30 30 30 Carbon black (4) 50 50 50 50 50 50 Oil (9) 10 10 10 10 10 10 Adhesive (10) 2 2 2 2 2 2 Vulcanizers (5) 2 2 2 2 2 2 Vulcanization accelerator 2 (11) One One One One One One Sulfur (7) 4 4 4 4 4 4

(1) Butyl rubber: Exxon Bromo-Butyl Rubber (pattern viscosity 28 to 36)

(2) Natural rubber: SIR-20 (Standard Indonesian Rubber)

(3) Epoxidized natural rubber: Epoxidised Natural Block Rubber (20% of epoxy group)

(4) Carbon black: GPF grade carbon black (N660)

(5) Varying agents: Zinc Oxide and Stearic Acid

(6) Vulcanization accelerator 1: MBTS (Dibenzothiazole Disulfide)

(7) Sulfur: Oil treated sulfur

(8) Styrene-butadiene rubber: SBR1502 (styrene content 22 to 25% by weight)

(9) Oil: Naphthenic Oil

(10) Adhesive: Phenol / Formaldehyde Resin

(11) Vulcanization accelerator 2: NS (N-tert-butyl-2-benzothiazole-sulfenamide)

[ Experimental Example : Measurement of physical properties of the prepared rubber composition]

The physical properties of the rubber specimens prepared in the Examples and Comparative Examples were measured in the following manner, and the results are shown in Table 2 below.

(1) 300% Modulus (kgf / cm 2): A dumbbell type having a length of 100 mm, an outer width of 25 mm and an inner width of 5 mm was used as a specimen and the tensile strength at 300% elongation was measured according to ISO 37 standard. The higher the value, the better the strength.

(2) Gas permeability: A circular specimen (diameter 50 mm, thickness 250 탆) was vulcanized at 170 캜 using an unvulcanized rubber, and the prepared specimen was measured at a measurement temperature of 30 캜 according to ISO 2782 test conditions The gas permeability was measured and indexed. The higher the value, the better the air permeability.

(3) Adhesive force: The upper and lower specimens were prepared using upper and lower specimens (upper side: 13 mm x 170 mm, lower side: 40 mm x 160 mm or more) using an unvulcanized rubber, and the upper and lower rubber specimens were adhered at a constant speed, The force of the time is measured.

(4) Tire weight: A tire having a width of 205 mm, a flatness ratio of 65%, a tire internal structure R (radial), and a wheel diameter of 15 in was manufactured using the rubber composition prepared above, and its weight was measured.

Item Comparative Example Example One 2 3 One 2 3 300% Modulus (1) 35 40 30 30 38 34 Gas Permeability (Index) (2) 100 94 106 112 96 105 Adhesion (Index) etc. Carpets upper topping rubber (3) 100 108 95 97 105 103 etc. Carcass code (3) 100 107 94 97 104 102 Tire Weight (kg) 205 / 65R15 Specification (4) 9.1 8.9 8.9 8.9 8.9 8.9

Referring to Table 2, it was confirmed that Comparative Examples 2 and 3, which did not include an inner liner, and Examples 1 to 3 were lighter than Comparative Example 1 including an inner liner.

As compared with Comparative Example 1, in Comparative Example 2 in which the amount of natural rubber was increased, the modulus was increased and the adhesive strength was increased, but it was confirmed that the gas permeability was lowered. This proves that natural rubber is disadvantageous to air permeability. On the other hand, in the case of Comparative Example 3, the gas permeability was improved by increasing the amount of butyl rubber, but the modulus and adhesion were decreased. This means that the butyl rubber has a disadvantage in adhesion to natural rubber.

Examples 1 to 3 show that a part of natural rubber is replaced by an epoxidized natural rubber. In the case of Example 1 in which the natural rubber of Comparative Example 2 was replaced by the epoxidized natural rubber, the air permeability was significantly improved as compared with Comparative Example 2. This indicates that the epoxidized natural rubber is advantageous to air permeability in comparison with general natural rubber. However, it was confirmed that the adhesion was in an unfavorable level. Example 2 showed that the amount of epoxidized natural rubber substituted in Comparative Example 2 was small, and as a result, it was confirmed that the adhesive strength was advantageous but the air permeability was inferior. The gas permeability and the adhesive force were improved compared with the comparative example in Example 3 in which the optimum amount was substituted. This result of Example 3 is advantageous for the method of introducing the inner liner into the carcass topping rubber.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

100: Tire Carcass
10: Carcass lower layer topping part comprising butyl rubber and epoxidized natural rubber
20: Containing styrene butadiene rubber Carcass upper layer topping
30: Carcass code
200: Rolling machine
101: Carcass lower layer topping rubber including butyl rubber and epoxidized natural rubber
201: Containing styrene butadiene rubber Carcass upper layer topping rubber

Claims (8)

Carcass code,
A rubber composition for a carcass lower layer topping comprising a butyl rubber and an epoxidized natural rubber is formed on the lower layer of the carcass cord top layer,
Containing styrene butadiene rubber Wherein the rubber composition for carcass upper layer topping comprises an upper layer topping layer topped on top of the carcass cord.
The method according to claim 1,
The rubber composition for carcass lower layer topping comprising the butyl rubber and the epoxidized natural rubber
100 parts by weight of a raw rubber comprising 65 to 85 parts by weight of butyl rubber, 10 to 30 parts by weight of natural rubber and 10 to 20 parts by weight of epoxidized natural rubber,
45 to 65 parts by weight of carbon black,
0.5 to 2.0 parts by weight of a curing agent,
0.5 to 1.5 parts by weight of a vulcanization accelerator, and
Sulfur 0.5 to 1.5 parts by weight
Wherein the tire is a tire.
3. The method of claim 2,
Wherein the butyl rubber is any one selected from the group consisting of butyl rubber (IIR), butyl rubber of bromine (Br-IIR), halogenated butyl rubber of chlorinated butyl rubber (Cl-IIR), and combinations thereof.
3. The method of claim 2,
Wherein the epoxidized natural rubber has 10 to 50% by weight of an epoxy group introduced into the natural rubber.
The method according to claim 1,
Containing styrene butadiene rubber The rubber composition for tire carcass upper layer topping comprises
60 to 80 parts by weight of natural rubber and 20 to 40 parts by weight of styrene butadiene rubber.
A rubber composition for a lower layer topping using a rubber composition for a carcass lower layer topping comprising a butyl rubber and an epoxidized natural rubber, and a rubber composition for top layer topping using a carcass upper layer topping rubber composition containing a styrene butadiene rubber ,
Preparing a rolling machine comprising rolls 1 to 4,
Placing the upper layer topping rubber between rolls 1 and 2,
Injecting the lower layer topping rubber between rolls 3 and 4, and
Passing the carcass cord between roll 2 and roll 3
Of the tire carcass.
A tire produced by using the tire carcass according to any one of claims 1 to 6.
8. The method of claim 7,
Wherein the tire does not include an inner liner.

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