WO2017052288A1

WO2017052288A1 - Pneumatic tire

Info

Publication number: WO2017052288A1
Application number: PCT/KR2016/010691
Authority: WO
Inventors: 정일; 김윤조; 최송연
Original assignee: 코오롱인더스트리 주식회사
Priority date: 2015-09-25
Filing date: 2016-09-23
Publication date: 2017-03-30
Also published as: KR20170037433A

Abstract

The objective of the present invention is to provide a pneumatic tire having an inner liner that can implement excellent airtightness even with a slim thickness, the tire preventing the inner liner from being deformed or cracked during the running of a vehicle, when repetitive deformation and high temperatures occur. The present invention relates to a pneumatic tire in which the distance, in the central direction of the tire, between a base film of the inner liner containing polyamide-based components and a cord of a carcass layer is at least 2.5 mm.

Description

【Specification】

[Name of invention]

Pneumatic tire

Technical Field

Cross Citation with Related Application (s)

This application claims the benefit of priority based on Korean Patent Application No. 10-2015-0137056 filed on September 25, 2015, and all the contents disclosed in the literature of that Korean patent application are incorporated as part of this specification.

The present invention relates to pneumatic tires.

[Invention and background technology]

The tires support the load of the vehicle, relieve the stratification from the road surface, and transmit the driving or braking force of the vehicle to the ground. In general, the tire is a composite of fiber / steel / rubber, and generally has a structure as shown in FIG.

Tread (1): It is a part in contact with the road surface, which provides the necessary frictional force for braking and driving, has good abrasion resistance, can withstand external stratification, and generates little heat.

Body Ply (or Carcass) (6): This is a layer of cord inside the tire, which must support loads, withstand impacts, and be resistant to flexing movements while driving.

Belt t (5): Located between the body plies, most of them are made of steel wielding to mitigate external shocks and maintain a wide tread ground for excellent driving stability. do.

Side Wal (3): It is the rubber layer between the lower part of the sled (2) and the bead (9), and serves to protect the inner body ply (6).

Inner Liner (7): Located on the inside of the tire instead of the tube, this prevents air leakage and enables pneumatic tires.

BEAD (9): A square or hexagon wi-re bundle with rubber coating on the wire that rests and secures the tire to the rim.

CAP PLY (4) ： On belts of radial tires for some passenger cars It is a special cord paper located to minimize the movement of the belt when driving.

APEX (8): A triangular rubber layering material used to minimize the dispersion of beads, to mitigate external shocks, to protect the beads, and to prevent the inflow of air during molding.

Recently, a tube-l ess tire in which high pressure air of about 30 to 40 ps i is injected is generally used without using a tube. In order to prevent this, a highly airtight inner liner is disposed in the carcass inner layer.

Previously, tire innerliers based on rubber components, such as butyl rubber or halo butyl rubber, which had relatively low air permeability, were used. In such innerlayers, the rubber content or the thickness of the innerlayer had to be increased to obtain sufficient airtightness. . However, when the content of the rubber component and the tire thickness increase, there is a problem that the total tire weight increases and fuel economy of the vehicle decreases.

In addition, the rubber components have relatively low heat resistance, such that air pockets are formed between the inner rubber and the inner layer of the carcass layer or the inner layer of the carcass layer during the vulcanization process of the tire, or the driving of the vehicle, where repeated deformation occurs at high temperature conditions. There was a problem in changing form or physical properties. In addition, in order to couple the rubber components to the tire curker layer, a vulcanizing agent or a vulcanizing process had to be applied, and thus, it was difficult to secure a sufficient adhesive force.

Accordingly, various methods have been proposed to reduce fuel consumption by reducing the thickness and weight of the inner layer, and to reduce the shape and physical properties of the inner layer generated in the process of forming or driving a tire.

However, the previously known inner liner has a phenomenon such as deterioration of its own properties or cracking of the film during the manufacturing process of a tire which is repeatedly formed at a high temperature, or during the driving process of a car where high heat is generated. appear. Thus, previously known innerliers have been used as a method of mixing elastically elastic components or stacking additional elastomeric layers on the innerlier layers. [Content of invention]

Problem to be solved

The present invention provides a pneumatic tire that can prevent the inner layer from being deformed or cracked during the driving process of a vehicle in which repeated deformation and high heat are generated while applying an inner layer that can realize excellent airtightness even with a thin thickness. It is to.

[Measures of problem]

In the present specification, a pneumatic tire having a distance in the tire center direction between the base film of the inner layer containing the polyamide-based component and the cord of the carcass layer is at least 0.25 mm or more.

Hereinafter, a pneumatic tire according to a specific embodiment of the present invention will be described in detail. In the present specification, the 'polyamide-based component' includes all of a polyamide-based resin, a monomer of the polyamide-based resin or a precursor of the polyamide-based resin, and a polyamide-based repeating unit included in a polymer or copolymer. . ^'

In addition, "segment" means a part having the same chemical structure or a specific part having the same physical properties in the polymer or compound. For example, a segment may be a specific repeating unit or a chemical structure in which these specific repeating units are aggregated, or may be a moiety or moiety derived from a semi-atom (monomer, oligomer, polymer, etc.) included in the final reaction product. According to an embodiment of the present invention, a pneumatic tire having a distance in the direction of the tire center between the base film of the inner layer including the polyamide-based component and the cord of the carcass layer may be at least 0.25 mm or more.

The inventors have found that the inner layer containing polyamide-based components can realize excellent airtightness even with a thin thickness, while frequently applied to pneumatic tires, the film itself is frequently damaged or deteriorated in properties during driving. By doing relevant research. Polyamide-based components If pneumatic tires are manufactured with a distance of at least 0.25 mm between the base film of the inner layer and the cord of the carcass layer, the inner tire may be formed. And it was confirmed through experiments that the inner layer can prevent the deformation or breakage of the inner layer by acting as a buffer layer between the film and the cord in the driving process of a car that generates high heat, and completed the invention. Pneumatic tires having a distance in the tire center direction between the base film of the inner layer including the polyamide-based component and the cord of the carcass layer have a minimum inner diameter of 0.25 誦 or more, as well as the inner structure of the inner layer film and the tire, Friction between internal structures that may occur during driving. By preventing damage due to impact or deformation, it is possible to secure high durability, fatigue resistance, and improved air pressure retention performance.

Specifically, the distance between the base film of the inner layer and the cord of the carcass layer and the tire center direction may be 0.25 kPa or more, or 0.25 kPa to 0.7 mm, or 0.26 kPa to 0.50 kPa.

If the shortest distance in the tire center direction between the base film of the inner layer and the cord of the carcass layer is less than 0.25 醒, the cord is popped through the rubber layer of the carcass layer or the base film of the inner layer in the pneumatic tire of the embodiment. Damage may occur, and wrinkles may be caused by the cord inside the tire even if the inner layer film is not damaged. In addition, if the shortest distance in the tire center direction between the base film of the inner layer and the cord of the carcass layer is less than 0.25 mm, the stress generated in the driving process and concentrated on the cord may not be alleviated by the rubber layer and the base of the inner layer Propagation directly to the film causes excessive deformation and tension of the inner layer, and also increases friction between the inner film of the inner layer and the cord of the carcass layer, thereby easily damaging the inner layer. On the other hand, when the distance in the tire center direction between the base film of the inner layer and the cord of the carcass layer is excessively far away, the weight of the tire is increased due to the use of unnecessary rubber, and the fuel economy may be deteriorated by the increased weight. . Also, without increasing the amount of rubber used, If the distance between the base film and the cord is too far, the distance between the cord and the steel belt becomes extremely small, and the friction between the cord and the steel belt may increase due to deformation during tire driving, and the cord may be damaged and the tire may be destroyed. have.

The distance in the tire center direction between the base film of the inner layer and the cord of the carcass layer may be defined as the shortest distance between any one of the cords of the carcass layer and the base film of the inner layer. In addition, the distance in the tire center direction between the base film of the inner layer and the cord of the carcass layer may be determined by the shortest distance between the one point of the outermost surface in the tire center direction of the tire cord and the surface of the base film of the inner layer.

For example, FIG. 2 schematically shows a tire cross section measured by SEM, and the distance from the tire cross section as shown in FIG. 2 to the center of the tire between the base film of the inner layer and the cord of the carcass layer is equal to the width direction of the pneumatic tire. It can be checked and measured in the horizontal cross section.

Specifically, the distance in the tire center direction between the base film of the inner layer and the cord of the carcass layer may be the shortest distance where the normal from the surface of the base film of the inner layer meets the cord in the entire pneumatic tire structure. For example, the length (D) of the arrow from the tire center direction indicated in FIG. 2 may be defined as the distance in the tire center direction between the base film of the inner layer and the cord of the carcass layer.

As described above, the inner liner including the polyamide-based component may realize excellent airtightness even at a thin thickness, and specifically, the inner liner including the polyamide-based component may have excellent airtightness, for example, a tire in the same thickness. Compared to the butyl rubber used as 10 to 20 times the degree of airtightness, but not high modulus exhibits an increase in the rigidity of the film at high temperature can be suppressed to prevent crystallization at high temperatures.

The base film of the inner layer may have a thickness of 10 to 300 in, preferably 20 to 250 im, more preferably 30 to 200 mm 3. In addition, the inner layer including the polyamide-based component has been previously Have a thinner thickness than known, but low air permeability, for example

It may have an oxygen permeability of 200 erf / (n · 24hr. Atm) or less.

On the other hand, the base film of the inner layer including the polyamide-based component may be substantially free of the rubber component, specifically, the content of the rubber component in the base film of the inner layer is 1% by weight or less, or 0.5% by weight Can be. The rubber component means a rubber component known to be commonly used in tires, and specifically, may be natural rubber, butyl rubber, or halo butyl rubber.

The inner layer including the polyamide-based component has a property of being able to be stretched or deformed to fit the shape of a tire even when a small force is applied with high airtightness.

Specifically, the lowering that occurs when the base film of the inner layer is stretched 100% at room temperature may be 0.5 to 4 kgf. In addition, the base film of the inner layer may have a load generated at 100% elongation after heat treatment at 180 ° C. for 10 minutes may be 6 kgf or less.

As such, when the inner layer is elongated at room temperature or high temperature, a specific range of ^' load ^' is generated due to the polyamide-based component included in the base film of the inner layer. The load that appears when the innerlayer is stretched at high or high temperatures can be optimized as the innerlayer.

When the inner layer is stretched at room temperature or high temperature, if too much load is generated, the external force such as severe tensile and compressive deformation that may occur in the driving process of the vehicle may be caused by the characteristic of the rigid film in the inner driving process. It may be concentrated in the area, causing cracks in the inner layer or tearing of the film itself.

Meanwhile, the base film of the inner layer including the polyamide-based component may include a copolymer including a polyamide-based segment and a polyether-based segment.

The base film of the inner layer containing the polyamide-based component is Including copolymers containing polyether-based segments that impart elastomeric properties along with polyamide-based segments, they exhibit 10 to 20 times the airtightness compared to butyl rubbers generally used in tires at the same thickness, but also have low modulus. It is possible to suppress the structural change due to the crystallization of the film by showing the russ characteristics, thereby improving the durability against tire deformation.

When the base film of the inner layer includes a copolymer including a polyamide segment and a polyether segment, the content of the polyether segment in the base film is increased by 2% by weight to 40% by weight¾. Can be.

When the content of the polyether-based segment is less than 2% by weight of the entire base film, the modulus of the base film or the inner layer may be increased, thereby reducing the moldability of the tire, or the physical property decrease due to repeated deformation. When the content of the polyether-based segmanto exceeds 40% by weight of the entire film, the tire inner liner required gas tightness (Gas Barr er) is not good, the tire performance may be reduced. The reaction resistance to the adhesive may be lowered, which may make it difficult for the inner layer to easily adhere to the carcass layer, and the elasticity of the base film may be increased, thereby making it difficult to manufacture a uniform film.

The weight average molecular weight of the copolymer including the polyamide-based segment and the polyether-based segment may be 30, 000 to 500, 000, or 7, 000 to 300, 000, or 90, 000 to 200, 000.

In this specification, a weight average molecular weight means the weight average molecular weight of polystyrene conversion measured by the GPC method. In the process of measuring the weight average molecular weight of polystyrene conversion measured by the GPC method, a detector and an analytical column, such as a commonly known analytical device and a differential refractive index detector (Refractive Index Detector), may be used. Temperature conditions, solvents and f low rates can be applied. Specific examples of the measurement conditions

Temperature of 30 ° C, chloroform solvent and f low rate of 1 mL / min ᅳ-Meanwhile, the base film of the inner layer may further include at least one polymer resin selected from the group consisting of polyamide resin and olefin polymer compound.

Such polyamide-based resin may be present in the inner layer in a state in which the polyamide-based segment and the polyether-based segment are copolymerized or in a co-polymerized state. The polyamide-based resin, which may be further included, may be used to improve the mechanical properties of the inner layer, for example, heat resistance or chemical stability, and airtightness, but if the amount used is too large, it may deteriorate the characteristics of the inner layer. Can be. In particular, even when the polyamide-based resin is additionally used, the content of the polyether-based segment in the base film of the inner layer should be maintained at 2% by weight to 40% by weight, and thus, the polyamide-based resin The sum of the contents of the polyamide-based segment and other additives may be 60 to 98 wt%.

The polyamide-based resin may have a relative viscosity (96% sulfuric acid solution) of 2.5 to 4.0, preferably 3.2 to 3.8. The relative viscosity of the polyamide-based resin refers to the relative viscosity measured using a 96% sulfuric acid solution at room temperature. Specifically, a sample of a certain polyamide-based resin (for example, 0.025 g of specimen) is dissolved in 96% sulfuric acid solution at different concentrations to prepare two or more measurement solutions (for example, a polyamide-based resin specimen). Dissolve in 96% sulfuric acid to make concentrations of 0.25 g / dL, 0.1 g / dL, and 0.05 g / dL, and make three measuring solutions) 상대 Relative viscosity of the measuring solution using a viscosity tube at 25 ° C (Example For example, the ratio of the average passage time of the measurement solution to the viscosity tube passage time of 96% sulfuric acid solution can be obtained.

Examples of the polyamide-based resin that can be used for the base film include polyamide-based resins such as nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 610, nylon 612 and nylon 6/66. Nylon 6/66/610 copolymer, nylon MXD6, nylon 6T, nylon 6 / 6T copolymer, Nylon 66 / PP copolymer and nylon 66 / PPS copolymer; Or their N-alkoxyalkylates, for example 6-nylon methoxymethylate, 6-610-nylon mesoxymethylate or 612-nylon mesoxymethylate, nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 610 or nylon 612 is preferred.

On the other hand, the base film of the inner layer by using the olefin-based polymer compound together with the polyamide-based component, it is possible to prevent the phenomenon that the inner layer is crystallized due to high temperature, outer layer spacing or deformation, and also the inner layer It is possible to improve fatigue resistance and durability even at low temperatures by lowering modulus properties or increasing elasticity while maintaining other mechanical properties of the above equivalent level.

Specifically, the olefin-based polymer compound serves to increase the flexibility (Sof tness) of the base film and to improve the ability to absorb the layer striking applied from the outside, and also to significantly lower the modulus of the base film The internal structure of the compound or polymer included in the base film is changed to prevent the phenomenon of crystallization.

The base film of the inner layer may include 3 wt% to 35 wt%, or 10 wt% to 30 wt% of the olefinic polymer compound. If the content of the olefin polymer compound is too small, the degree of action and effect according to the olefin polymer compound may be insignificant. In addition, if the content of the olefin polymer compound is too large, the base film of the inner layer may be used. Therefore, the reduction of physical properties due to heat in the high temperature vulcanization process during tire production may occur.

The olefin polymer compound may include an olefin polymer, an olefin copolymer, an olefin polymer or copolymer grafted with dicarboxylic acid or an acid anhydride thereof, or a mixture of two or more thereof.

The olefinic polymer may include polyethylene, polypropylene or a mixture thereof.

The olefin copolymer is an ethylene-propylene copolymer, or an ethylene-acrylic ester-maleic anhydride terpolymer (Ethylene-Acryl ic Ester-Maleic Anhydride terpolymer, acrylic ester and maleic anhydride functional! Zed polyolefin, ethylene-butylacrylate-glycidyl methacrylate terpolymer (Terpolymer of ethylene, butylacrylate (BA) and glycidyl met hacry late (GMA)). As described above, the olefin polymer compound may include an olefin polymer or copolymer grafted with dicarboxylic acid or an acid anhydride thereof, and the dicarboxylic acid may be maleic acid, phthalic acid, itaconic acid, or citraconic acid. ， Alkenylsuccinic acid, cysulf 1,2,3,6 tetrahydrophthalic acid, 4-methyl-1, 1,2,3,6 tetrahydrophthalic acid, or a combination of two or more thereof, and the dicarboxyl The dianhydride of the acid may be the dicarboxylic dianhydride of the examples described above.

The content of the dicarboxylic acid or its acid anhydride grafted in the olefinic polymer or copolymer grafted with the dicarboxylic acid or acid anhydride thereof may be 0.3% by weight or more, preferably 0.5% by weight to 3.0% by weight. May be%.

The grafting ratio of such dicarboxylic acid or its acid anhydride can be measured from the result obtained by acid-base titrating the said olefin type high molecular compound. For example, about lg of the above-mentioned olefinic polymer compound was put in 150 ^ xylene saturated with water, and refluxed for about 2 hours. Then, a small amount of 1% by weight thymolblue-dimethylformamide solution was added, and 0.05N sodium hydroxide-ethyl alcohol solution. After titration slightly to obtain a ultramarine blue solution, the solution was again titrated until 0.05N hydrochloric acid-isopropyl alcohol solution was yellowish, and the acid value was obtained. From this, the dicarboxyl grafted to the olefinic polymer compound was obtained. Can calculate the amount of acid

The olefinic polymer compound may have a density of 0.77 g / cm 'to 0.95 g / crf, or 0.80 g / cm ³ to 0.93 g / cm'.

On the other hand, the carcass insect and the base film of the inner layer may be bonded via a resorcinol-formin-latex (RFL) -based adhesive and an adhesive layer having a thickness of 0.1 to 20 mm 3. The adhesive layer including the resorcinol-formalin-latex (RFL) -based adhesive has excellent adhesion and adhesion retention performance to the base film and the tire carcass layer, and thus, heat generated during manufacturing or driving of the tire. Alternatively, breakage of the interface between the inner layer film and the carcass layer caused by repeated deformation may be performed so that the inner layer polymer film may have sufficient fatigue resistance.

The resorcinol-formalin-latex (RFL) -based adhesive is 2 to 32% by weight, preferably 10 to 20% by weight, and latex 68 to 98% by weight of condensate of resorcinol and formaldehyde, preferably 80 to 90% by weight. May contain%.

The condensate of resorcinol and formaldehyde may be obtained by mixing resorcinol and formaldehyde in a molar ratio of 1: 0.3 to 1: 3.0, preferably 1: 0.5 to 1: 2.5, and then condensing reaction. In addition, the condensate of resorcinol and formaldehyde may be included in more than 2% by weight relative to the total amount of the adhesive layer in terms of chemical reaction for excellent adhesion, and may be included in less than 32% by weight to ensure proper fatigue resistance properties. have. Wherein, the latex is a natural rubber latex, a stitcher run 1 / butadiene rubber latex, acrylonitrile / butadiene rubber latex, chloroprene rubber latex and at ^least, or as mixtures of two or more thereof selected from the group consisting of styrene / butadiene / vinylpyridine rubber latex Can be. The latex may be included in an amount of 68% by weight or more based on the total amount of the adhesive layer for flexibility of the material and effective crosslinking reaction with rubber, and 98% by weight or less for the chemical reaction with the base film and the rigidity of the adhesive layer.

The adhesive layer may have a thickness of 0.1 to 20, preferably 0.01 to 10, more preferably 0.2 to 7 m, even more preferably 0.3 to 5.

On the other hand, the pneumatic tire may have a structure of a commonly known pneumatic tire except for the content of the distance in the direction of the tire center between the base film of the inner layer including the polyamide-based component and the cord of the carcass layer. have. For example, the pneumatic tire is a tread portion; remind A pair of sled parts each continuously connected to both sides with a tread part; A pair of side wall portions continuous to each of the sled portions; A pair of bead portions continuous to each of the sidewall portions; A carcass layer formed inside the tread portion, the sulde portion, the side wall portion, and the bead portion; A cord located within the carcass layer; A belt part disposed between the inner surface of the tread part and the carcass layer; And an inner layer coupled to the inside of the carcass layer.

【Effects of the Invention】

According to the present invention, the pneumatic tire that can prevent the deformation or breakage of the inner liner in the process of driving the car, such as repeated deformation and high heat while applying the inner liner that can realize excellent airtightness even in a thin thickness is Can be provided.

The pneumatic tire is not only stable in the inner liner film and the tire inner structure installed therein, but also prevents damage due to friction, shock or deformation between the inner structures that may occur in a vehicle driving process, thereby increasing high durability and fatigue resistance and Improved air pressure retention performance can be obtained.

[Brief Description of Drawings]

1 schematically shows the structure of a pneumatic tire.

Figure 2 schematically shows the tire cross section measured by SEM. [Specific contents to carry out invention]

The invention is explained in more detail in the following examples. However, the following examples are merely to illustrate the invention, but the content of the present invention is not limited by the following examples.

[Examples and Comparative Examples: Production of Inner Liar Film and Pneumatic Tire] <Example 1>

(1) Production of base film

Polyamide-based resin (nylon 6) having a relative viscosity (96% solution of sulfuric acid) 3.4 prepared from ε-caprolactam and a copolymer resin having a weight average molecular weight of about 95, 000 (polytetramethylene oxide at the amine group end) doing Synthesized using 15 weights of polyether-based segments and 85 weights of polyamide-based segments derived from ε-caprolactam, and maleic anhydride (0.7 weight ethylene-propylene copolymer (density: 0.870 g / cm ³ )) To 40: 35: 25, and 1 part by weight of the oxazoline compound and 100 parts by weight of the mixture and the heat-resistant [composite of copper iodide and potassium iodide-7% by weight of copper (Cu) in the mixture ^ 0.2 parts by weight was added to prepare a mixture for producing a base film.

The mixture is then extruded at 255 ° C through a T-shaped die (Die Gap-0.9 kPa), maintaining a uniform melt flow, and air cooled at 20 ^o C. The molten resin was cooled and solidified to form a film of uniform thickness. Then, an unstretched base film having a thickness of 100 was obtained without passing through the stretching and heat treatment sections at a rate of 10 m / min.

(2) application of adhesive

Resorcinol and formaldehyde were mixed at a molar ratio of 1: 2, and then condensed to form a condensate of resorcinol and formaldehyde. 15 weight ¾ of condensate of resorcinol and formaldehyde and 85 weight% of styrene / butadiene-1,3 / vinylpyridine latex were mixed to obtain a resorcinol-formalin-latex (RFL) adhesive having a concentration of 25%. .

Then, this resorcinol-formalin-latex (RFL) -based adhesive was coated on both sides of the unstretched base film using a gravure coater and at 150 ° C.

After drying and reacting for 1 minute to form an adhesive layer having a thickness of 2. on each side to prepare an inner layer film.

(3) Manufacture of pneumatic tires

The inner layer film is inserted into a tire forming drum, and then the tires are manufactured by sequentially laminating a carcass layer forming rubber, a bead wire, a belt part, a cap ply part, and an outer rubber layer, or forming a sheet-shaped inner layer film. The tire was manufactured after raising to the drum for the formation of the splice part on it. At this time, the same reflecting the decrease in the thickness of the inner layer The diameter of the forming drum was increased by 3 mm to produce a green tire of the size, thereby manufacturing a passenger tire of the 225 / 45R17 standard.

The carcass layer close to the inner layer is a cord fabric of polyester 1300 De 72 in the rubber. The cord diameter of 1300 De / 2 is 0.63 隱 and the thickness of the entire carcass layer including the rubber layer surrounding it is 1.2 Nylon 66 1260/2 was used for the cap ply. The shortest distance from the cord of the said carcass layer measured after tire vulcanization to the innerlayer base film was measured about 0.35 kPa. Example 2

The inner layer film was prepared in the same manner as in Example 1 except that the thickness of the entire carcass layer including the rubber layer was increased by increasing the thickness of the rubber layer surrounding the carcass layer, thereby manufacturing a pneumatic tire. . At this time, the distance from the cord of the carcass insect to the innerlayer substrate film was measured to be 0.42 kPa. Example 3

The inner layer film was prepared in the same manner as in Example 1 except that the thickness of the entire carcass layer including the rubber layer was reduced by reducing the thickness of the rubber layer surrounding the carcass layer, thereby manufacturing a pneumatic tire. At this time, the distance from the cord of the carcass layer to the inner layer substrate film was measured to be 27 kW. Example 4

An inner layer film was produced in the same manner as in Example 1, except that a 1 mm thick reinforcing rubber was placed at a width of 50 mm in the tire amount show ratio, thereby manufacturing a pneumatic tire. At this time, the distance from the cord of the carcass layer to the inner layer substrate film was measured to be 0.39 mm. Comparative Example 1 Rubber blended and extruded 1.3 隱 of an inner layer compound containing 50% by weight of butyl rubber, 27% by weight of carbon black, 20% by weight of fiber filler, 1% by weight of paraffin oil, 1% by weight of zinc oxide, and 1% by weight of stearic acid. An inner layer film was prepared, and the same tire specifications as in Example 1 were prepared by combining the carcass layer and the like after raising the film on a forming drum. Comparative Example 2

An innerlayer film was prepared in the same manner as in Example 1 except that the green tire was made small by not increasing the diameter of the forming drum by 3 mm, thereby manufacturing a pneumatic tire. At this time, the distance from the cord of the carcass layer to the inner layer substrate film was measured to be 0.12 mm. Comparative Example 3

Innerlayer film and pneumatic tire were manufactured in the same manner as in Example 4, except that the green tire was made small by not increasing the diameter of the molding drum by 3 mm. The distance from the innerlayer base film to the innerlayer film was measured at 0.1½ 111 _.

Experimental Example: Measurement of Physical Properties of Inner Liar Film

Experimental Example 1: Measurement of the load that occurs when the inner film is stretched

After the heat treatment at 180 ° C for 10 minutes with a load generated by stretching 100% in the direction of MD (Machine Direction) at room temperature

The load occurring at 100% elongation was measured. The specific measuring method is as follows.

(1) Measuring instrument: Universal Testing Machine (Model 4204, Instron)

(2) Measurement condition: 1) Head Speed 300rara / min, 2) Grip Di stance (Sample

Length) 100mm, 3) Sample Width 10mm, 4) 25 ° C and 60RH% Atmosphere

(3) It measured five times each and calculated | required the average value. Experimental Example 2: Oxygen Permeability Experiment

For the base film obtained in the above Examples and Comparative Examples, using a Gas Transmi ss ion Rate Tester (Model BR—l / BT-1, manufactured by Toyose iki Sei saku-Sho Co., Ltd.) by ASTM D 1434, Oxygen permeability was measured under atmosphere. Experimental Example 3: Experiment of Ease of Molding

By applying the polymer film of the above Examples and Comparative Examples as an inner liner, 100 tires were manufactured by 205R / 65R16. Increased tire manufacturing process After the production of green tires, the ease of manufacture and appearance were evaluated, and the final appearance of the tires after vulcanization was examined.

At this time, if the tire after the green tire or vulcanization is not crushed, the standard deviation of the diameter is within 5% was evaluated as 'good'. In addition, when the tire is not properly manufactured because the tire is crushed due to the green tire or the vulcanization, or the inner tire of the tire is melted or torn and broken, or when the standard deviation of the diameter exceeds 5%, the tire is evaluated as 'bad'.

The ease of molding was evaluated by identifying the number of tires having a good appearance with respect to 100 tires manufactured by applying the polymer films of Examples and Comparative Examples as inner tires of the tire, and the molding ease was obtained as shown in the following general formula (1). .

^' * ^{ ¾ at 11 ^ £ HH

* ¾ ^ l¾ <%) »ιαο {)

Experimental Example 4: Durability Measurement Experiment

The FMVSS139 tire durability measurement method was used to increase the load and to evaluate the durability of the tire manufactured in Experimental Example 3. This endurance measurement is based on the endurance test and speed which increases the load by the step load method. Two methods of increasing high speed test were carried out to check for cracks in the tire and marked 'good' if there was no crack and 'bad' if it occurred.

By evaluating the final appearance of the tire by the method of Experimental Example 3, 20 tires were selected for the appearance of 'good' tires, and each of the 10 tires was subjected to an endurance test and a high speed test to confirm the occurrence of 'cracks'. After the durability measurement, the durability of the tire according to the endurance test and the high speed test was obtained as the number of 'good' tires without cracks.

Experimental Example 5: Pneumatic holding performance test

The tire manufactured in Experimental Example 3 was prepared using ASTM F1112-06.

90 days of air pressure retention (IPR: Internal Pressure Retent ion) was measured and evaluated under a pressure of 101.3 kPa at 21 ° C.

<Formula 3> 100

The results of Experimental Examples 1 to 5 are shown in Table 1 below.

Table 11

After heat treatment at 180 ° C for 10 minutes 3. 1 3. 1 3. 1 3. 1 0.3 3. 1 3. 1

100% elongated

Load (kgf)

Oxygen Permeability 85 85 85 85 1000 85 85 [cmV (m'-24hratm)] Excessive Moldability (%) 98 99 98 96 99-81 88 Tire Endurance 100 100 100 100 100 10 20 Durability Test

(%)

High Speed 100 100 100 100 98 100 100 Test

Pneumatic Retention Rate (%) 98.2 98. 1 98.2 98. 1 97.2 98.0 98.2 As shown in Table 1, the inner film of the inner layer was made by increasing the diameter of the tire manufacturing mold forming drum and increasing the rubber of the reinforcing rubber or the carcass layer. When the distance between the and the cord is sufficiently secured to be 0.25 mm or more, it is confirmed that relatively excellent durability can be secured and excellent air pressure retention and high speed performance are realized.

On the contrary, when there is no change in the diameter of the forming drum or the like, the thickness of the rubber is greatly reduced at the shoulder portion of the pneumatic tire, and the distance between the base film of the inner layer and the cord is too close, resulting in damage to the inner liner film (Comparative Example). 1) endurance of durability evaluation of the pneumatic tire is manufactured on the inner Liar ^film, and tensile strain is excessively applied to be durable and significantly less are viewed point (Comparative examples 2 and 3).

Claims

[Claim]

[Claim 1]

A pneumatic tire having a distance in the tire center direction between the base film of the inner layer containing the polyamide-based component and the cord of the carcass layer at least 2.5 mm or more.

[Claim 2]

The method of claim 1,

A pneumatic tire, wherein the distance in the tire center direction between the base film of the inner layer and the cord of the carcass layer is 0.25 kPa to 0.7 kPa.

[Claim 3]

The method of claim 1,

The pneumatic tire whose content of the base film thickening rubber component of the said inner layer is 1 weight% or less.

[Claim 4]

The method of claim 1,

Pneumatic tire is a load generated when the base film of the inner layer 100% elongation at room temperature 0.5 to 4 kgf.

[Claim 5]

The method of claim 1,

A pneumatic tire having a load generated at 100% elongation after heat-treating the base film of the inner layer at 180 ^° C. for 10 minutes, which is 6 kgf or less.

[Claim 6]

The method of claim 1,

The base film of the inner layer has a thickness of 10 to 300, Pneumatic tire

[Claim 7]

The method of claim 1,

The base film of the inner layer is. Pneumatic tire, comprising a copolymer comprising a polyamide segment and a poly ether segment.

[Claim 8]

The method of claim 7,

The pneumatic tire, wherein the base film thickener has a content of 2% by weight to 40% by weight of the polyether-based segment.

[Claim 9]

The method of claim 7, wherein

The inner layer base film further comprises at least one polymer resin selected from the group consisting of polyamide-based resins and olefin-based polymer compounds, pneumatic tires.

[Claim 10]

The method of claim 9,

The olefin-based high molecular compound is a pneumatic tire comprising one or more compounds selected from the group consisting of olefin-based polymers, olefin-based copolymers and dicarboxylic acids or acid anhydrides thereof olefin-based polymers or copolymers .

[Claim 11]

The method of claim 9,

The base film of the inner layer comprises 3 to 35% by weight of the olefin polymer compound, pneumatic tire.

[Claim 12]

The method of claim 9,

The olepin-based polymer compound has a density of 0.77g / cffl 'to 0.95 g / cm ³ , pneumatic tire.

[Claim 13]

The method of claim 9,

The olefin-based polymer compound is a pneumatic tire comprising an olefin-based polymer or copolymer grafted at least 0.3% by weight of dicarboxylic acid or acid anhydride thereof.

[Claim 14]

In that U term,

The carcass layer and the base film of the inner layer comprise a resorcinol-formalin-latex (RFL) -based adhesive and are bonded through an adhesive layer having a thickness of 0.1 to 20.

[Claim 15]

The method of claim 1,

The pneumatic tire is a tread portion; A pair of sled parts each connected to both sides about the tread part; A pair of side wall portions continuous to each of the sled portions; A pair of bead portions continuous to each of the sidewall portions; A carcass layer formed inside the tread portion, the shoulder portion, the sidewall portion, and the bead portion; A cord located within the carcass layer; A belt part disposed between the inner surface of the tread part and the carcass layer; And an inner layer coupled to the inside of the carcass layer.