KR20130004146A - Film for tire inner-liner and preparation method thereof - Google Patents

Abstract

PURPOSE: A film for a tire inner liner is provided to obtain excellent air tightness or moldability and to prevent the damages of product or blocking phenomenon. CONSTITUTION: A film for a tire inner liner comprises: a base film layer which comprises a polyamide-based resin, a copolymer with a polyamide-based segment and polyether-based segment; an adhesive layer which is formed at least one side of the base film and comprises a resorcinol-formalin-latex-based adhesive; and a release film layer which is formed on the adhesive layer and comprises a polymer film with the initial modulus of 1500 Mpa or more. The polyether-based segment content of the copolymer is 15-50 weight% based on the total weight of the based film layer. [Reference numerals] (1) Tread; (2) Shoulder; (3) Side wall; (4) Capply; (5) Belt; (6) Body ply; (7) Inner liner; (8) Apex; (9) Bead

Description

FILM FOR TIRE INNER-LINER AND PREPARATION METHOD THEREOF}

The present invention relates to a film for a tire inner liner and a method for manufacturing the same, and more particularly, to achieve excellent airtightness even at a thin thickness, thereby making it possible to reduce tire weight and improve automobile fuel efficiency, and to have excellent airtightness. Alternatively, the present invention relates to a thinner inner liner film and a method for manufacturing the tire inner liner, which can realize physical properties such as moldability and can prevent damage or blocking of a product occurring during long-term storage.

The tires support the load of the vehicle, alleviate the impact from the road surface, and transmit the driving or braking force of the vehicle to the ground. In general, a tire is a composite of fiber / steel / rubber and generally has a structure as shown in FIG. 1.

Tread (1): This part is to be in contact with the road surface to provide the necessary frictional force for braking and driving, to have good abrasion resistance, to withstand external shocks, and to generate little heat.

Body Ply (or Carcass) (6): A layer of cord inside the tire, which must support loads, withstand impacts, and be resistant to fatigue during rolling.

Belt (5): Located between the body plies, consisting of steel wires in most cases to mitigate external shocks and maintain a wide tread ground to provide excellent driving stability.

Side Wall (3): refers to the rubber layer between the lower part of the shoulder (2) from the bead (9) and serves to protect the body ply (6) inside.

Inner Liner (7): Located on the inside of the tire instead of the tube, it prevents air leakage to enable pneumatic tires.

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

CAP PLY (4): A special cord paper placed on the belt of some passenger radial tires that minimizes belt movement when driving.

APEX (8): A triangular rubber filler used to minimize the dispersion of beads, to mitigate external impacts, to protect the beads, and to prevent the ingress of air during molding.

Recently, tube-less tires in which high pressure air of about 30 to 40 psi is injected without the use of a tube are commonly used. To this end, a highly airtight inner liner is disposed in the carcass inner layer.

Previously, tire inner liners were used, which consist mainly of rubber components such as relatively low air permeability butyl rubber or halo butyl rubber, which had to increase the rubber content or the thickness of the inner liner in order to obtain sufficient airtightness. . As the content and thickness of the rubber component increases, the total tire weight increases and fuel economy of the vehicle decreases, and an air pocket or an inner liner is formed between the inner rubber and the inner liner of the carcass layer during the vulcanization process of the tire or the driving of the vehicle. The phenomena of the shape and physical properties were also changed.

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

However, previously known methods have had limitations in maintaining good air permeability and tire formability while sufficiently reducing the thickness and weight of the innerliner. In addition, the inner liner obtained by the previously known method has often failed to have sufficient fatigue resistance such as cracking due to repeated deformation in the manufacturing process or the running process of the tire. In addition, the previous tire innerliner does not have good adhesion to the carcass layer inside the tire, so that the tire inner liner may be separated or peeled off during the tire manufacturing process or the automobile driving process. In addition, the previous tire innerliner has a problem in that the product is damaged due to long-term repeated pressure or external impact due to poor elasticity or flexibility, and blocking occurs between different film layers. .

The present invention can realize excellent airtightness even at a thin thickness, thereby making it possible to reduce the weight of a tire and improve fuel efficiency of an automobile, and to realize physical properties such as excellent airtightness or formability, and to prevent damage or blocking of a product generated during long-term storage. An object of the present invention is to provide a film for a thinner innerliner that can prevent development.

Moreover, this invention is providing the manufacturing method of the said film for tire innerliners.

The present invention is a substrate film layer comprising a polyamide-based resin and a copolymer comprising a polyamide-based segment and a polyether-based segment; An adhesive layer formed on at least one surface of the base film layer and including a resorcinol-formalin-latex (RFL) adhesive; And a release film layer formed on the adhesive layer and including a polymer film having an initial modulus of 1500 Mpa or more at room temperature, wherein the content of the polyether-based segment of the copolymer is 15 to 50 based on the total weight of the base film layer. It provides the film for tire innerliner which is weight%.

In addition, the present invention melts and extrudes a mixture between a polyamide-based resin and a copolymer including a polyamide-based segment and a polyether-based segment at 230 to 300 ° C. to extrude the base film layer. Forming a; Forming an adhesive layer including a resorcinol-formalin-latex (RFL) adhesive on at least one surface of the base film layer; And forming a release film layer including a polymer film having an initial modulus of 1500 Mpa or more at room temperature on the adhesive layer, wherein the content of the polyether-based segment included in the copolymer is based on the total weight of the base film layer. It provides the manufacturing method of the film for tire innerliners which is 15 to 50 weight%.

Hereinafter, a method for manufacturing the tire inner liner film and the tire inner liner film according to a specific embodiment of the present invention will be described in detail.

According to an embodiment of the present invention, a base film layer including a polyamide-based resin and a copolymer including a polyamide-based segment and a polyether-based segment; An adhesive layer formed on at least one surface of the base film layer and including a resorcinol-formalin-latex (RFL) adhesive; And a release film layer formed on the adhesive layer, the release film layer including a polymer film having an initial modulus of 1500 Mpa or more at room temperature, wherein the content of the polyether-based segment of the copolymer is 15 to 50 weight based on the total weight of the base film layer. %, A film for tire innerliner may be provided.

As a result of the researches of the present inventors, by using a base film prepared by mixing a polyamide-based resin and the specific copolymer described above, it is possible to realize excellent airtightness even at a thin thickness to lighten the tire and improve the fuel efficiency of the automobile, It has been confirmed that a film for a tire innerliner that has heat resistance and exhibits excellent moldability and mechanical properties such as high durability and fatigue resistance can be provided.

In particular, the base film may exhibit high reactivity to the above-described adhesive layer due to the characteristic chemical structure, and the adhesive layer may also exhibit high and uniform adhesion to the tire carcass layer. Accordingly, the inner liner film can be firmly bonded to the tire without applying an additional vulcanization process or significantly increasing the thickness of the adhesive layer, and a tire manufacturing process or a long time repeated physical deformation to which a high temperature deformation or stretching step is applied. In this vehicle driving process, the bonding force between the inner liner film and the tire carcass layer may be greatly reduced, or the breakage between the base film and the adhesive layer may be prevented.

In addition, since the tire innerliner film does not require a large amount of additives or rubber components for improving physical properties, the manufacturing process can be simplified and the tire manufacturing cost can be reduced. Accordingly, the tire inner liner film can improve the fuel efficiency of the vehicle by reducing the weight of the tire, and maintain the proper air pressure even after long-term use, to prevent the fallover accident and fuel economy lowered caused by low air pressure, and also when driving Its excellent ability to withstand repeated fatigue ensures durability, and it is possible to manufacture tires with excellent performance even with a simple manufacturing process.

On the other hand, the modulus when the base film is 100% elongated at room temperature may be 10 to 40 Mpa, preferably 15 to 35 Mpa. By applying the base film having such a modulus property, the tire innerliner film not only has excellent moldability in the tire manufacturing process but also stably maintains physical properties even in the severe deformation during tire molding, and is not very large during tire molding. Even when a force is applied, it can be stretched or deformed to fit the shape of the tire. In addition, the tire to which the tire innerliner film is applied may not significantly change the modulus or rigidity even after long-term driving, and may minimize the crack of the inner structure of the tire that may occur during the driving.

The modulus refers to an elastic modulus representing a ratio of stress and strain, and specifically refers to a slope value of a stress-elongation graph (S-S curve) measured at room temperature and 100% elongation point.

When the base film is stretched 100% at room temperature, the stress at the yield point may be 35 Mpa or less, preferably 25 Mpa or less, or more preferably, no Yield point may be present. The yield point refers to an elongation point at which elastic deformation occurs, and the strength at yield point refers to a limit stress or maximum value of stress at a point at which such elastic deformation occurs. As such, when the base film is 100% elongated at room temperature, the strength at the yield point is 35 MPa or less, so that the modulus difference between the tire inner liner film and the rubber such as the tire carcass layer may not be large. Separation phenomenon of the film and the rubber due to expansion in the molding process can be prevented, so that a good green tire shape can be obtained. In addition, when such a tire-based film is used, stress concentration phenomenon may be alleviated in the shoulder portion of the tire in which deformation is concentrated due to the modulus of the film, which is increased due to expansion even after the tire is manufactured. And the effect of preventing bending can be expressed.

On the other hand, the tire inner liner film is a release film containing a specific polymer resin is formed on the adhesive layer, it is possible to minimize the cracks or cracks that may occur due to repeated pressure or external impact when stored for a long time, the It is possible to prevent the phenomenon in which the modulus is increased by being stretched by the tension applied from the outside when the tire inner liner film is wound or when the tire is manufactured. In addition, the release film layer may be firmly bonded to the adhesive layer with an appropriate bonding force, for example, a product storage process, and may be easily separated without actually affecting the adhesive layer or the base film layer in the actual process application. It can have a degree of bonding force. Accordingly, the release film layer may prevent a phenomenon in which the inner liner film product is damaged by a long time repeated pressure or external impact or a blocking phenomenon that is stuck between different film layers.

As described above, the initial modulus of the release film may be 1500 Mpa or more, preferably 2000 MPa or more, or 1500 Mpa to 5,000 Mpa. As the release film has the above-described modulus characteristics, it is possible to minimize cracks or cracks that may occur due to repeated pressure or external impact for a long time, and may be applied externally during winding of the tire inner liner film or during tire manufacture. It is possible to prevent the phenomenon in which the modulus is increased by the tension and increases, and the workability of the tire inner liner film can be easily applied to the process. The initial modulus refers to the modulus of the release film in the unstretched state.

In particular, the tire inner liner film may be installed to enter the tire bead portion, or in order to express the adhesive force of the concave portion of the inner liner film, an adhesive layer may be formed on both sides of the base film, wherein the release film layer is a substrate The adhesive layers formed on both sides of the film can be prevented from being fused to each other.

The polymer film included in the release film layer may include a polyolefin resin, a polyester resin, a mixture thereof, or a copolymer thereof. Polyethylene resin, polypropylene resin, and the like may be used as the polyolefin resin, and polyethylene terephthalate resin and the like may be used as the polyester resin.

As the release film layer includes the above-described polymer resin, the release film layer may be firmly bonded to the adhesive layer with an appropriate bonding force, for example, a product storage process, and the adhesive layer or the base film in the actual process application. It can have a bonding force that can be easily separated without any influence on the product, and prevents the product from being damaged by long-term repeated pressure or external impact or blocking between the different film layers. can do.

And, the release film layer may have a thickness of 5 to 50um, preferably 8 to 35um. If the release film layer is too thin, it may be unable to prevent repeated pressure or external impact, and if the separation for the manufacture of tires due to too light characteristics, the operation may be interrupted by cutting or breaking, the phenomenon that is easily blown by air It can occur and stick to other objects with low modulus. In addition, when the release film layer is too thick, the manufacturing cost may be increased more than necessary, and may not be easily removed in the tire manufacturing process due to the high modulus.

On the other hand, the above-described tire inner liner film is characterized in that the base film layer is prepared using a copolymer comprising a polyether-based segment and a polyamide-based segment of a specific content together with the polyamide-based resin.

More specifically, the base film layer may have a relatively low modulus with excellent airtightness by using a polyamide-based resin together with a specific copolymer comprising polyether-based segments in a specific content to impart elastomeric properties. have. That is, the polyamide-based resin included in the base film layer exhibits excellent airtightness due to inherent molecular chain properties, for example, about 10 to 20 times higher than that of butyl rubber generally used in tires at the same thickness. The modulus is not so high compared to other resins. In addition, the polyether-based segment of the copolymer may be present in a bonded or dispersed state between polyamide-based segments or polyamide-based resins, thereby lowering the modulus of the base film layer, and the base film layer The increase in the rigidity of can be suppressed and the crystallization at high temperature can be prevented.

Since the polyamide-based resin generally exhibits excellent airtightness, the polyamide-based resin has a role of allowing the base film layer to have low air permeability while having a thin thickness. In addition, since the polyamide-based resin exhibits a modulus that is not relatively higher than that of other resins, an innerliner film that exhibits relatively low modulus characteristics even when applied with a copolymer including the polyether-based segment having a specific content is selected. It can obtain, and can improve the moldability of a tire by this. Also, Since the polyamide-based resin has sufficient heat resistance and chemical stability, the innerliner film may be prevented from being deformed or modified when exposed to chemical substances such as high temperature conditions or additives applied in the tire manufacturing process.

In addition, the polyamide-based resin is used in combination with a copolymer comprising a polyamide-based segment and a polyether-based segment, and thus relatively high relative to an adhesive (for example, a resorcinol-formalin-latex (RFL) -based adhesive). May indicate reactivity. Accordingly, the inner liner film may be easily adhered to the carcass portion, and the inner liner film may be sufficiently prevented by breaking the interface due to heat or repetitive deformation occurring during the tire manufacturing process or the driving process. Allow to have fatigue.

The polyamide-based resin may have a relative viscosity (96% solution of sulfuric acid) of 3.0 to 3.5, preferably 3.2 to 3.4. If the viscosity of the polyamide-based resin is less than 3.0, sufficient elongation may not be secured due to toughness deterioration, and thus damage may occur during tire manufacturing or driving of a vehicle, and the airtightness that the base film layer should have as a film for tire innerliner or It may be difficult to secure physical properties such as moldability. In addition, when the viscosity of the polyamide-based resin is more than 3.5, the modulus or viscosity of the base film layer to be produced may be unnecessarily high, and it may be difficult for the tire innerliner to have proper moldability or elasticity.

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, 0.10 g / dL, and 0.05 g / dL, and make three measuring solutions), and the relative viscosity of the measuring solution using a viscosity tube at 25 ° C. , 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 layer 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 methoxymethylate of 6-nylon, methoxymethylate of 6-610-nylon or methoxymethylate of 612-nylon, nylon 6, nylon 66, nylon Preference is given to using 46, nylon 11, nylon 12, nylon 610 or nylon 612.

The polyamide-based resin may be included in the base film layer by preparing a base film using a monomer of the polyamide-based resin or a precursor of the polyamide-based resin as well as a method of using the resin itself.

Meanwhile, as described above, the copolymer including the polyamide-based segment and the polyether-based segment is present in a bonded or dispersed state between the polyamide-based resins. Modulus of the base film layer can be lowered more, the rigidity of the base film layer can be suppressed from rising, and crystallization at high temperature can be prevented. As the specific copolymer is included in the base film layer, the tire innerliner film may realize high elasticity or elastic recovery while securing excellent mechanical properties such as durability, heat resistance and fatigue resistance. Accordingly, the inner liner film may exhibit excellent moldability, and the tire to which the inner liner film is applied may not be physically damaged or its physical properties or performance may be degraded even during a vehicle driving process in which repeated deformation and high heat are continuously generated. have.

On the other hand, when the content of the polyether segment of the copolymer is 15 to 50% by weight, preferably 20 to 45% by weight, more preferably 22 to 40% by weight based on the total weight of the base film layer, the tire The innerliner film can exhibit more excellent physical properties and performance. When the content of the polyether-based segment is less than 15% by weight of the entire base film layer, the modulus of the base film layer or the tire inner liner film is increased to reduce the moldability of the tire or to significantly decrease the physical properties due to repeated deformation. May appear. When the content of the polyether segment exceeds 50% by weight of the entire film, the tire innerliner is not good gas tightness (Gas Barrier) property is not good tire performance can be reduced. It may be difficult for the innerliner to easily adhere to the carcass layer because the reactivity to the adhesive may be reduced, and the elasticity of the base film layer may be increased to make it difficult to prepare a uniform film.

The polyether-based segment may be present in the state of being bonded to the polyamide-based segment or dispersed between the polyamide-based resins. It is possible to suppress or prevent the base film layer from being easily broken.

Such a polyether-based segment can lower the modulus of the film for the tire inner liner, thereby allowing the tire to be easily stretched or deformed to fit the shape of the tire even when a very small force is applied during the tire forming. To be able. In addition, the polyether-based segment can suppress the increase in the rigidity of the film at low temperatures and prevent crystallization at high temperatures, and can prevent damage or tearing of the inner liner film due to repeated deformation, etc. By improving the resilience to the deformation of the liner to suppress the occurrence of wrinkles of the film due to permanent deformation it can improve the durability of the tire or innerliner.

The polyamide-based segment may serve to allow the copolymer to have a certain level or more of mechanical properties but not to significantly increase the modulus properties. In addition, as the polyamide-based segment is applied, the base film layer may have a low air permeability while having a thin thickness, and may secure sufficient heat resistance and chemical stability.

The polyamide-based segment of the copolymer may include a repeating unit of Formula 1 or Formula 2.

[Formula 1]

In Formula 1, R ₁ is a linear or branched alkylene group having 1 to 20 carbon atoms or a linear or branched arylalkylene group having 7 to 20 carbon atoms.

(2)

In Formula 2, R ₂ is a linear or branched alkylene group having 1 to 20 carbon atoms, R ₃ is a straight or branched alkylene group having 1 to 20 carbon atoms or a straight or branched arylalkyl having 7 to 20 carbon atoms. It's Rengi.

In addition, the polyether segment of the copolymer may include a repeating unit represented by the following Formula 3.

[Formula 3]

In the general formula (3), R ₅ is a linear or branched alkylene group having 1 to 10 carbon atoms, n is an integer of 1 to 100, R ₆ and R ₇ may be the same or different and are each a direct bond, -O -, -NH-, -COO- or -CONH-.

The absolute weight average molecular weight of the copolymer including the polyamide-based segment and the polyether-based segment may be 50,000 to 300,000, preferably 70,000 to 200,000. If the absolute weight average molecular weight of the copolymer is less than 50,000, the base film layer to be produced may not secure sufficient mechanical properties for use in the inner liner film, and the tire inner liner film may have sufficient gas barrier. It can be difficult to secure. In addition, when the absolute weight average molecular weight of the copolymer is more than 300,000, the modulus or crystallinity of the base film layer is excessively increased when heated to a high temperature, it may be difficult to secure the elasticity or elastic recovery to have as an inner liner film.

On the other hand, the copolymer is a polyamide segment and a polyether segment in the range of 15 to 50% by weight based on the total weight of the film, the polyether segment 6: 4 to 3: 7, preferably 5: 5 to 4: 6.

As described above, when the content of the polyether-based segment is too small, the modulus of the base film layer or the tire innerliner film may be increased, thereby deteriorating the moldability of the tire or a large decrease in physical properties due to repeated deformation. In addition, if the content of the polyether-based segment is too large, the airtightness of the film for the tire inner liner may be lowered, the reactivity to the adhesive is lowered, it is difficult for the inner liner to easily adhere to the carcass layer, The elasticity of the film layer may be increased and thus it may not be easy to produce a uniform film.

In addition, in the base film layer, the polyamide-based resin and the copolymer described above may be included in a weight ratio of 6: 4 to 3: 7, preferably 5: 5 to 4: 6. If the content of the polyamide-based resin is too small, the density or airtightness of the base film layer may be lowered. In addition, when the content of the polyamide-based resin is too large, the modulus of the base film layer may be excessively high or the moldability of the tire may be lowered, and the polyamide-based resin may be Crystallization may occur and cracks may occur due to repeated deformation.

On the other hand, the base film layer may be an unstretched film. When the base film layer is in the form of an unstretched film, it has a low modulus and a high strain rate and can be suitably applied to a tire forming process in which high expansion occurs. In addition, since crystallization hardly occurs in the unstretched film, damage such as cracks can be prevented even by repeated deformation. In addition, since the unoriented film does not have a large variation in the orientation and physical properties in a specific direction, an inner liner having uniform physical properties can be obtained.

As shown in the method of manufacturing the film for tire innerliner described later, a method of suppressing the orientation of the base film as much as possible, for example, adjusting viscosity by optimizing the melt extrusion temperature, changing the die die specification, and adjusting the installation position of the cooling roller. The base film may be manufactured as an unoriented or unoriented film by adjusting an air knife installation position, adjusting a pinning device (electrostatic imparting device), or adjusting a winding speed.

When the unstretched film is applied to the base film, the inner liner film can be easily produced in a cylindrical or sheet form in a tire manufacturing process. In particular, when the non-stretched sheet-like film is applied to the base film, it is not necessary to construct a film manufacturing facility for each tire size, and it is preferable because the impact and wrinkles applied to the film can be minimized during the transport and storage process. . In addition, when the base film is manufactured in a sheet form, a process of adding an adhesive layer to be described later may be more easily performed, and damage or crushing occurring during the manufacturing process may be prevented due to a difference in specifications with a forming drum.

The base film layer may have a thickness of 30 to 300 ㎛, preferably 40 to 250 ㎛, more preferably 40 to 200 ㎛. Accordingly, the film for tire innerliner of one embodiment of the invention has a thinner thickness than previously known, but may have a low air permeability, for example, an oxygen permeability of 200 cc / (m 2 · 24hr · atm) or less. have.

The base film may further include additives such as heat resistant antioxidants, heat stabilizers, adhesion promoters, or mixtures thereof. Specific examples of the heat resistant antioxidants include N, N'-hexamethylene-bis- (3,5-di- (t-butyl) -4-hydroxy-hydrocinnamamide (N, N'-Hexamethylene-bis- (Commercially available products such as 3,5-di-tert-butyl-4-hydroxy-hydrocinnamamide such as rganox 1098), tetrakis [methylene (3,5-di- (t-butyl) -4-hydroxyhydrocinnanam Mate)] methane (commercially available products such as tetrakis [methylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate)] methane, such as Irganox 1010) or 4,4'-dicumyldiphenylamine (4,4 ') -di-cumyl-di-phenyl-amine, such as Naugard 445. Specific examples of the heat stabilizer include benzoic acid, triacetonediamine, or N, N'-bis (2). , 2,6,6-tetramethyl-4-piperidyl) -1,3-benzenedicarboxamide (N, N'-Bis (2,2,6,6-tetramethyl-4-piperidyl) -1 , 3-benzenedicarboxamide), etc. However, the additive is not limited to the above examples, and may be used for the film for tire inner liner. It is known can be used without limitation.

On the other hand, the adhesive layer comprising the resorcinol-formalin-latex (RFL) -based adhesive has excellent adhesion and adhesion retention performance to the base film layer and the tire carcass layer, and thus in the manufacturing process or running process of the tire It is possible to prevent breakage of the interface between the inner liner film and the carcass layer generated by the generated heat or repeated deformation so that the inner liner film may have sufficient fatigue resistance.

The main properties of the adhesive layer described above appear to be due to the inclusion of certain resorcinol-formalin-latex (RFL) based adhesives having a specific composition. Previously, adhesives for tire innerliners have been used, such as rubber type tie gums, and thus require additional vulcanization. In contrast, the adhesive layer includes a resorcinol-formalin-latex (RFL) -based adhesive having a specific composition, and has high reactivity and adhesion to the base film, and is compressed under high temperature heating conditions without increasing the thickness. The base film and the tire carcass layer may be firmly bonded. Accordingly, it is possible to reduce the weight of the tire and to improve the fuel efficiency of the automobile, and to prevent the phenomenon of separating the carcass layer and the inner liner layer or the base film and the adhesive layer even during repeated deformation in the tire manufacturing process or the automobile driving process. Can be. In addition, since the adhesive layer may exhibit high fatigue resistance against physical and chemical deformations that may be applied during tire manufacturing or driving, the adhesive force may be applied even during the manufacturing process under high temperature conditions or during the driving of a vehicle in which mechanical deformation is applied for a long time. The degradation of other physical properties can be minimized.

In addition, the resorcinol-formalin-latex (RFL) -based adhesives are capable of crosslinking between latex and rubber, thereby exhibiting adhesive performance, and because they are physically latex polymers, have low curing properties and thus have flexible properties such as rubber. , Chemical bonding between the metirol end of the lesosinol-formalin polymer and the base film is possible. Accordingly, when the resorcinol-formalin-latex (RFL) -based adhesive is applied to the base film, sufficient adhesion performance can be realized.

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

The condensate of resorcinol and formaldehyde may be obtained by mixing the 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 condensation reaction. In addition, the condensate of the 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 in order to secure proper fatigue resistance properties. have.

The latex may be one or a mixture of two or more selected from the group consisting of natural rubber latex, styrene / butadiene rubber latex, acrylonitrile / butadiene rubber latex, chloroprene rubber latex, and styrene / butadiene / vinylpyridine rubber latex. The latex may be included in more than 68% by weight relative to the total amount of the adhesive layer for the flexibility of the material and the effective crosslinking reaction with the rubber, it is included in 98% by weight or less for the chemical reaction with the base film and the rigidity of the adhesive layer.

In addition, the adhesive layer may further include at least one additive such as a surface tension modifier heat-resistant agent, an antifoaming agent, and a filler, together with a condensate and latex of resorcinol and formaldehyde. At this time, the surface tension modifier of the additive is applied for the uniform coating of the adhesive layer, but may cause a problem of the adhesive strength decrease when excessively added, 2 wt% or less or 0.0001 to 2 wt%, preferably based on the total adhesive layer 1.0 wt% or less, or 0.0001 to 0.5 wt%. At this time, the surface tension modifiers sulfonate anionic surfactant, sulfate ester salt anionic surfactant, carboxylate anionic surfactant, phosphate ester salt anionic surfactant, fluorine-based surfactant, silicone-based surfactant and polysiloxane-based surfactant It may be one or more selected from the group consisting of.

The adhesive layer may have a thickness of 0.1 to 20 μm, preferably 0.1 to 10 μm, more preferably 0.2 to 7 μm, even more preferably 0.3 to 5 μm, and one surface of the film for tire innerliner or It can be formed on both surfaces. If the thickness of the adhesive layer is too thin, the adhesive layer itself may be thinner when the tire is inflated, the crosslinking adhesive force between the carcass layer and the base film may be lowered, and stress may be concentrated on a part of the adhesive layer, thereby reducing fatigue characteristics. In addition, when the adhesive layer is too thick, interfacial separation may occur in the adhesive layer, thereby reducing fatigue characteristics. And, in order to adhere the inner liner film to the carcass layer of the tire, it is common to form an adhesive layer on one surface of the base film, but in the case of applying a multilayer inner liner film or the inner liner film wrapping the bead part, etc. And it is preferable to form an adhesive layer on both sides of the base film when rubber and adhesion on both sides according to the structural design.

On the other hand, the tire inner liner film can maintain the proper air pressure even after long-term use, for example, the tire inner liner film at 21 ℃ and 101.3 kPa in accordance with the method of ASTM F 1112-06 standards When the internal pressure retention (IPR) was measured for 90 days on the applied tire, the air pressure retention ratio as shown in the following general formula 2 was 95% or more, preferably 96.5% or more, that is, the air pressure reduction rate was 5% or less. Preferably, it may be 3.5% or less. Accordingly, by using the tire inner liner film, it is possible to prevent a rollover accident and fuel consumption reduction caused by low air pressure.

 [Formula 2]

Meanwhile, according to another embodiment of the present invention, a mixture of a polyamide-based resin and a copolymer including a polyamide-based segment and a polyether-based segment is melted at 230 to 300 ° C. Extruding to form a base film layer; Forming an adhesive layer including a resorcinol-formalin-latex (RFL) adhesive on at least one surface of the base film layer; And forming a release film layer including a polymer film having an initial modulus of 1500 Mpa or more at room temperature on the adhesive layer, wherein the content of the polyether-based segment included in the copolymer is based on the total weight of the base film layer. 15 to 50% by weight, a method for producing a film for tire innerliner may be provided.

According to the manufacturing method, not only excellent thickness and high air pressure retention performance can be realized even at a thin thickness, but also the base film exhibits high reactivity with a certain adhesive, so that the thin and light weight adhesive layer can be applied to the inside of the tire. A film for a tire innerliner can be provided that can be firmly and uniformly coupled and can be easily elongated or deformed even when a small force is applied during tire forming, thereby exhibiting excellent molding properties and improved fatigue resistance. In addition, the tire inner liner film includes a release film layer containing a specific polymer, so that the inner liner film product is damaged due to prolonged repeated pressure or external impact or blocking between the different film layers. The phenomenon can be prevented.

As described above, the modulus when the base film is 100% elongated at room temperature may be 10 to 40 Mpa, preferably 15 to 35 Mpa, and yield point when the base film is 100% elongated at room temperature The stress at the point may be 35 Mpa or less, preferably 25 Mpa or less, or more preferably, no yield point. Specific details on the modulus characteristics or the strength at the yield point of the base film under the stretching conditions are as described above.

Details of the copolymer including the polyamide-based resin, the polyamide-based segment, and the polyether-based segment are as described above.

On the other hand, in the step of forming the base film layer, in order to extrude a film having a more uniform thickness, the copolymer and the polyamide-based resin may be adjusted to have a uniform size. As such, as the size of the copolymer and the polyamide-based resin are adjusted, the copolymer and the polyamide-based resin may be mixed in the step of mixing them, staying at a raw material supply unit maintained at a constant temperature, or melting and extruding. The resin may be more uniformly mixed, and the copolymer and the polyamide-based resin may be prevented from increasing in size by being aggregated with each other or with each other, whereby a base film layer having a more uniform thickness may be formed. .

When the copolymer and the polyamide-based resin have a similar size, it is possible to minimize the phenomenon that the raw material chips agglomerate or appear uneven shape or region in the subsequent mixing, melting or extrusion step, and thus the film A base film layer having a uniform thickness can be formed over the entire area. The size of the copolymer and the polyamide-based resin that can be used in the production method is not particularly limited.

On the other hand, the tire innerliner film production method may further comprise the step of mixing the polyamide-based resin and the copolymer in a weight ratio of 6: 4 to 3: 7. If the content of the polyamide-based resin is too small, the density or airtightness of the base film layer may be lowered. In addition, when the content of the polyamide-based resin is too large, the modulus of the base film layer may be excessively high or the moldability of the tire may be lowered, and the polyamide-based resin may be Crystallization may occur and cracks may occur due to repeated deformation. In this mixing step, any device or method known to be used for mixing the polymer resin can be used without particular limitation.

The polyamide-based resin and the copolymer may be injected into a raw material feeder after being mixed, or may be mixed by being injected sequentially or simultaneously with the raw material feeder.

As described above, the copolymer may include a polyamide-based segment and a polyether-based segment in a weight ratio of 6: 4 to 3: 7.

The mixture of the polyamide-based resin and the copolymer may be supplied to the extrusion die through a raw material supply unit maintained at a specific temperature, for example, 50 to 100 ° C. As the raw material supply unit is maintained at a temperature of 50 to 100 ℃, the mixture of the polyamide-based resin and the copolymer has a physical property such as an appropriate viscosity can be easily moved to another part of the extrusion die or extruder, It is possible to prevent the poor feeding of the raw material (feeding) phenomenon that occurs due to agglomeration of the mixture, it is possible to form a more uniform base film in the subsequent melting and extrusion process. The raw material supplier is a part that serves to supply the raw material injected from the extruder to the extrusion die or other parts, the configuration is not limited to a large, and is a conventional raw material feeder (feeder) included in the extruder for producing a polymer resin, etc. Can be.

On the other hand, by melting and extruding the mixture supplied to the extrusion die through the raw material supply unit at 230 to 300 ℃, it is possible to form a base film layer. The temperature for melting the mixture may be 230 to 300 ℃, preferably 240 to 280 ℃. The melting temperature should be higher than the melting point of the polyamide-based compound, but if it is too high, carbonization or decomposition may occur and the physical properties of the film may be hindered. Unstretched may occur due to bonding between the polyether-based resins or orientation in the fiber array direction. It may be disadvantageous for producing a film.

The extrusion die may be used without any limitation as long as it is known that it can be used for extrusion of the polymer resin, but in order to make the thickness of the base film more uniform or to prevent the orientation of the base film from using a T-type die It is preferable.

On the other hand, the step of forming the base film layer, the mixture of the copolymer comprising the polyamide-based resin, polyamide-based segments and polyether-based segments of 30 to 300 ㎛ And extruding into a film of thickness. The adjustment of the thickness of the film to be produced can be made by adjusting the extrusion conditions, for example, the extruder discharge amount or the gap of the extrusion die, or by changing the winding speed of the cooling process or recovery process of the extrudate.

In order to more uniformly control the thickness of the base film layer in the range of 30 to 300 μm, the die gap of the extrusion die may be adjusted to 0.3 to 1.5 mm. In the step of forming the base film, if the die gap (Die Gap) is too small, the die shear pressure of the melt extrusion process is too high and the shear stress is so high that it is difficult to form a uniform shape of the extruded film and the productivity is lowered If the die gap is too large, the stretching of the melt-extruded film may be too high, the orientation may occur, the difference in physical properties between the longitudinal and transverse direction of the substrate film to be produced may be increased.

In addition, in the method for producing a film for tire innerliner, a portion of an extrusion die corresponding to a position at which a non-uniform thickness appears by continuously measuring the thickness of the base film manufactured by the above-described steps, and feeding back a measurement result. For example, the film having a more uniform thickness can be obtained by reducing the deviation of the base film manufactured by adjusting the lip gap adjusting bolt of T-Die. In addition, the adjustment of the thickness measurement-feedback-extrusion die of such films can be configured by using an automated system such as an Auto Die system or the like.

On the other hand, the base film of the film for tire innerliner can be obtained by manufacturing the result of the melt extrusion step into an unstretched film having a thickness of 30 to 200 ㎛. The thickness of the extrudate can be adjusted according to the specifications of the apparatus such as the extruder used. In addition, in order to form an unstretched film, a method of optimizing the melt extrusion temperature to adjust the viscosity of the melt, the amount of ejection of the melt, change the specification of the die gap (ap), or adjust the winding speed of the film Etc. can be used. The winding speed of the film is preferably maintained at an appropriate speed in order to prevent problems of poor cooling and increase in the degree of orientation, for example, by applying a speed of 100m / min or less, preferably 50m / min or less by maximally suppressing the winding speed can do.

On the other hand, the method for producing a film for tire innerliner may further comprise the step of solidifying the base film layer formed by melting and extruding in a cooling unit maintained at a temperature of 5 to 40 ℃, preferably 10 to 30 ℃. Can be.

The base film layer formed by melting and extruding may be provided on a film having a more uniform thickness by being solidified in a cooling unit maintained at a temperature of 5 to 40 ° C. The substrate film layer obtained by melting and extruding may be grounded or adhered to the cooling unit maintained at the appropriate temperature so that the stretching may not occur substantially, and the substrate film layer may be provided as an unstretched film.

In detail, the solidifying step may be performed by using an air knife, an air nozzle, an electrostatic charge device (Pinning device), or a combination thereof, on a cooling roll having the base film layer formed by melting and extruding at a temperature of 5 to 40 ° C. It may include the step of uniformly contact.

In the solidifying step, the base film layer formed by melting and extruding by using an air knife, an air nozzle, an electrostatic pinning device or a combination thereof is brought into close contact with a cooling roll. It is possible to prevent phenomena such as blowing in the air or cooling partially unevenly, so that a film having a more uniform thickness can be formed, and some areas of the film that are relatively thick or thin as compared to the surrounding part are substantially It may not be formed as.

The melt extruded under the above specific die gap condition may be attached or grounded to a cooling roll installed at a constant distance, for example, a horizontal distance of 10 to 150 mm, preferably 20 to 120 mm, from the die outlet to exclude stretching and orientation. The horizontal distance from the die outlet to the chill roll may be the distance between the die outlet and the point where the discharged melt grounds to the chill roll. If the straight line distance between the exit of the die and the cold roll attachment point of the molten film is too small, the uniform flow of the molten extruded resin may be disturbed and the film may be unevenly cooled, and if the distance is too large, the stretching effect of the film may be achieved. Can not.

In the step of forming the base film, except for the specific steps and conditions described above, extrusion processing conditions of the film commonly used in the production of the polymer film, for example, screw diameter, screw rotational speed, or line speed, etc. Can be selected and used appropriately.

On the other hand, the method for manufacturing a film for tire innerliner may include forming an adhesive layer including a resorcinol-formalin-latex (RFL) adhesive on at least one surface of the base film layer.

The adhesive layer including the resorcinol-formalin-latex (RFL) -based adhesive may be formed by coating a resorcinol-formalin-latex (RFL) -based adhesive on one surface of the base film layer, and the resorcinol- It can also be formed by laminating an adhesive film comprising a formalin-latex (RFL) -based adhesive on one surface of the base film layer.

Preferably, the forming of the adhesive layer may be performed by coating a resorcinol-formalin-latex (RFL) -based adhesive on one or both surfaces of the formed base film and then drying. The formed adhesive layer may have a thickness of 0.1 to 20 ㎛, preferably 0.1 to 10 ㎛. The resorcinol-formalin-latex (RFL) -based adhesive may comprise 2 to 32% by weight of condensate of resorcinol and formaldehyde and 68 to 98% by weight of latex, preferably 80 to 90% by weight.

More specific information regarding the resorcinol-formalin-latex (RFL) adhesive of the specific composition is as described above.

The coating or coating method or apparatus conventionally used for the application of the adhesive may be used without any limitation, but may be a knife coating method, a bar coating method, a gravure coating method or a spray method, or a dipping method. Can be used. However, it is preferable to use a knife coating method, a gravure coating method, or a bar coating method in terms of uniform application and coating of the adhesive.

After the adhesive layer is formed on one or both surfaces of the base film, the drying and the adhesive reaction may be simultaneously performed, but may be divided into the heat treatment reaction step after the drying step in consideration of the reactivity of the adhesive, In order to apply the thickness of the adhesive layer or the adhesive of the multi-stage, the adhesive layer forming, drying and reaction steps may be applied several times. In addition, after the adhesive is applied to the base film, the heat treatment may be performed by solidifying and reacting under heat treatment conditions at about 30 seconds to 3 minutes at 100 to 150 ° C.

In forming the copolymer or mixture, or melting and extruding the copolymer, additives such as a heat resistant antioxidant or a heat stabilizer may be further added. Details of the additives are as described above.

On the other hand, the method for producing a tire innerliner film may include forming a release film layer including a polymer film having an initial modulus of 1500 Mpa or more on the adhesive layer at room temperature.

Such a release film layer may be formed on the adhesive layer through a conventionally known method for laminating a polymer film or applying or coating a polymer resin. In addition, in the step of winding up after applying the adhesive to the base film, the release film layer may be laminated on the adhesive layer by winding the release film layer together.

Specifically, the step of forming the release film layer, by applying at least one polymer selected from the group consisting of polyolefin-based resin and polyester resin on the adhesive layer to form a release film layer having a thickness of 5 um to 50 um. step; Or laminating a film including at least one polymer selected from the group consisting of a polyolefin resin and a polyester resin on the adhesive layer to form a release film layer having a thickness of 5 um to 50 um.

As described above, the release film layer may have an initial modulus of 2500 Mpa or more, preferably 3000 Mpa or more. In addition, the polymer film included in the release film layer may include a polyolefin resin, a polyester resin, a mixture thereof, or a copolymer thereof. The release film layer may have a thickness of 5 to 50um, preferably 8 to 35um.

According to the present invention, it is possible to implement excellent airtightness even at a thin thickness, thereby making it possible to reduce the weight of the tire and improve the fuel efficiency of the automobile, and to realize physical properties such as excellent airtightness or formability, and damage to the product generated during long-term storage. Alternatively, there is provided a tinner inner liner and a method of manufacturing the tire inner liner, which can prevent a blocking phenomenon.

1 schematically shows the structure of a tire.

The invention is explained in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

Example: Production of Film for Tire Inner Liner

Example 1

(1) Production of base film

40% by weight of polyamide-based resin (nylon 6) having a relative viscosity (96% solution of sulfuric acid) 3.4 and a copolymer resin having an absolute weight average molecular weight of 100,000 (including 50% by weight of each polyamide repeating unit and polyether repeating unit) Mix 60% by weight, 260? At the temperature the mixture was melt extruded into a T-die under die gap 0.6 mm conditions.

The unstretched base film having a thickness of 80 μm was obtained without stretching the molten extrudate at a rate of 30 m / min and undergoing heat treatment. The thickness of the base film was measured using a gauge tester.

(2) application of adhesive

Resorcinol and formaldehyde were mixed in a molar ratio of 1: 2, and then condensation reaction was carried out to obtain a condensate of resorcinol and formaldehyde. 12% by weight of the condensate of resorcinol and formaldehyde and 88% by weight of styrene / butadiene-1,3 / vinylpyridine latex were mixed to obtain a resorcinol-formalin-latex (RFL) adhesive having a concentration of 20%.

In addition, the resorcinol-formalin-latex (RFL) -based adhesive was coated on the base film with a thickness of 3 μm using a gravure coater, dried and reacted at 150 ° C. for 1 minute to form an adhesive layer.

(3) Formation of Release Film Layer

A polyethylene terephthalate stretched film having an initial modulus of 4200 Mpa and a thickness of 12 μm was manufactured in a roll form. In the winding step after applying the adhesive to the base film, the polyethylene terephthalate stretched film was wound together to release a release film on the adhesive layer.

Example 2

20% by weight of polyamide-based resin (nylon 6) having a relative viscosity (96% solution of sulfuric acid) 3.4 and a copolymer resin having an absolute weight average molecular weight of 100,000 (containing 50% by weight of each polyamide repeating unit and polyether repeating unit) Except for using 80% by weight, the tire innerliner film was prepared in the same manner as in Example 1.

Example 3

A tire inner liner film was manufactured in the same manner as in Example 1 except that the thickness of the base film was 100 μm.

Example 4

The resorcinol-formalin-latex (RFL) adhesive of Example 1 was formed on both sides of the base film to a thickness of 3 μm, and a polyethylene terephthalate stretched film having an initial modulus of 3900 Mpa and a thickness of 12 μm was used. Except for the tire innerliner film was prepared in the same manner as in Example 1.

Comparative Example: Production of Film for Tire Inner Liner

Comparative Example 1

A tire inner liner film was manufactured in the same manner as in Example 1 except that a 3 μm adhesive layer was formed on both surfaces of the base film obtained in Example 1, and a release film was not laminated on the adhesive layer.

Comparative Example 2

The release agent and the processing agent were added to the butyl rubber, mixed and refined to obtain a base film having a thickness of 80 μm, and an adhesive rubber (tie gum) having a thickness of 3 μm was formed on the base film.

A polyethylene terephthalate stretched film having an initial modulus of 4200 Mpa and a thickness of 12 μm was manufactured in a roll form. In the winding step after applying the adhesive to the base film, the polyethylene terephthalate stretched film was wound together to release a release film on the adhesive layer.

Comparative Example 3

90% by weight of polyamide-based resin (nylon 6) having a relative viscosity (96% solution of sulfuric acid) 3.4 and a copolymer resin having an absolute weight average molecular weight of 100,000 (including 50% by weight of each polyamide repeating unit and polyether repeating unit) A tire innerliner film was prepared in the same manner as in Example 1 except that 10 wt% was used.

Comparative Example 4

10% by weight of polyamide-based resin (nylon 6) having a relative viscosity (96% solution of sulfuric acid) 3.4 and a copolymer resin (30% by weight of polyamide repeating unit and 70% by weight of polyether repeating unit) with an absolute weight average molecular weight of 100,000 It was prepared in the same manner as in Example 1 except that 90% by weight of the tire innerliner film was prepared.

Experimental Example: Measurement of Physical Properties of Tire Inner Liner Film

Experimental Example 1 Measurement of modulus at modulus and yield point at 100% elongation at room temperature

The strength at the modulus and yield point at 100% elongation in the MD (Machine Direction) direction of the base films obtained in Examples and Comparative Examples 3 and 4 was measured. The specific measuring method is as follows.

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

(2) Measurement conditions: 1) Head Speed 300mm / min, 2) Grip Distance 100mm, 3) Sample: Width 30mm * Length 30mm, 4) 20 ℃ and 65RH% atmosphere

(3) It measured 5 times each and calculated | required the average value.

The measurement results are shown in Table 1 below.

Results of Experiment 1 Example 1 Example 2 Example 3 Example 4 Comparative Example 3 Comparative Example 4 Modulus at room temperature 100% elongation [Mpa] 30 22 29 30 59 13 Strength at yield point at 100% elongation [Mpa] 27 19 26 27 43 X

As shown in Table 1, in the base film of the embodiment, the modulus at 100% elongation at room temperature is maintained in the range of 10 to 35 Mpa and the stress at the yield point is 35 Mpa or less, so that the tire It was confirmed that it can have a proper formability in the manufacturing process, and can ensure excellent fatigue resistance against repeated deformation while having sufficient mechanical strength even in the process of driving a car.

On the contrary, the base film of Comparative Example 3 had a modulus at 100% elongation at room temperature of 59 Mpa, so it was difficult to be sufficiently deformed or elongated in the tire manufacturing process, and the base film of Comparative Example 4 had a modulus at 100% elongation at room temperature. 13 Mpa, the yield point does not appear at 100% elongation at room temperature, the tire formability or workability was secured to some extent, but as described later, it was confirmed that the airtightness or air pressure retention characteristics were very low.

Experimental Example 2: Oxygen Permeability Experiment

Oxygen permeability of the tire innerliner film obtained in the above Examples and Comparative Examples was measured. The specific measuring method is as follows.

(1) Oxygen permeability: The method of ASTM D 3895 was measured in the atmosphere of 25 degree | times 60RH% using the Oxygen Permeation Analyzer (Model 8000, the product of Illinois Instruments).

Experimental Example 3: Measurement of Air Pressure Holding Performance

Tires were manufactured by applying tire inner liner films of Examples and Comparative Examples to 205R / 65R16. In addition, the manufactured tires were compared and evaluated by measuring the IPR Internal Pressure Retention for 90 days under a pressure of 101.3 kPa at 21 ° C. using ASTM F1112-06.

Experimental Example 4. Ease of Molding Measurement

Tires were manufactured by applying tire inner liner films of Examples and Comparative Examples to 205R / 65R16. During the tire manufacturing process, the manufacturing ease and appearance were evaluated after the production of green tires, 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, if the tire is not properly manufactured due to crushing on the tire after the green tire or the vulcanization, or the inner liner inside the tire is melted or torn, the tire is damaged or the standard deviation of the diameter exceeds 5%. .

The results of Experimental Examples 2 to 4 are shown in Table 2 below.

Results of Experimental Examples 2 to 4 Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Tire manufacturing Good Good Good Good Bad shape Good Bad shape Good Oxygen Permeability 72 91 65 72 72 900 25 More than 1000 windage
Maintenance performance
(decrease%) 2.1 2.4 1.5 2.1 - 20 - 30

As shown in Table 2, the tire innerliner film obtained in the example exhibited an oxygen permeability of 100 cc / (m 2 · 24hr · atm) or less, not only having excellent airtightness, but also measured by Experimental Example 2 above 90 The daily internal pressure retention (IPR) of more than 95% was found to prevent overturning accidents and fuel economy reduction caused by low air pressure.

In addition, as described above, the film for the tire innerliner of the embodiment may not only exhibit proper moldability in the tire manufacturing process by having appropriate modulus characteristics and yield strength characteristics, but also occur during long-term storage including a release film. Product damage or blocking can be prevented and workability in the tire manufacturing process can be improved.

On the contrary, the film for tire innerliner of the comparative example did not exhibit proper formability or workability in the tire manufacturing process due to a relatively poor physical property or a blocking phenomenon of sticking between different film layers.

Specifically, in the case of the film for tire innerliner of Comparative Example 1, the adhesive liquid on both sides stuck to each other while being fused while releasing the film from the roll to manufacture the tire, causing deformation of the film. There was a problem that the adhesive liquid stuck to one side and the adhesion with the rubber was not properly expressed.

In the case of the tire inner liner films of Comparative Examples 2 and 4, it was possible to manufacture a tire by having a constant moldability, but the airtightness and air pressure holding performance were poor, and thus it was not sufficient to be applied to an actual tire.

In the case of the tire inner liner film of Comparative Example 3, due to the high modulus characteristics, crushing occurred in the manufactured green tire because the expansion was not sufficiently performed in the turn-up process during tire molding, and thus the tire manufacturing was not easy.

Tread
2. shoulder
3. Side Wall
4. CAP PLY
5. Belt
6. Body Ply
7. Inner Liner
8. Apex
9. BEAD

Claims (22)

A base film layer comprising a polyamide-based resin and a copolymer including a polyamide-based segment and a polyether-based segment;
An adhesive layer formed on at least one surface of the base film layer and including a resorcinol-formalin-latex (RFL) adhesive; And
And a release film layer formed on the adhesive layer and including a polymer film having an initial modulus of 1500 Mpa or more at room temperature.
A tire inner liner film, wherein the content of the polyether segment of the copolymer is 15 to 50% by weight based on the total weight of the base film layer.
The method of claim 1,
The film for tire innerliner having a modulus of 10 to 40 Mpa at 100% elongation at room temperature.
The method of claim 1,
A film for tire innerliner having a stress at a yield point of the base film at 100% elongation at room temperature of 35 MPa or less.
The method of claim 1,
The film for tire innerliners whose relative viscosity (96% solution of sulfuric acid) of the said polyamide resin is 3.0-3.5.
The method of claim 1,
A film for tire innerliner having an absolute weight average molecular weight of 50,000 to 300,000 of the copolymer including the polyamide-based segment and the polyether-based segment.
The method of claim 1,
Polyamide-based segment of the copolymer is a tire innerliner film comprising a repeating unit of the following formula (1) or (2):
[Chemical Formula 1]

In Formula 1, R ₁ is a linear or branched alkylene group having 1 to 20 carbon atoms or a straight or branched arylalkylene group having 7 to 20 carbon atoms,
(2)

In Formula 2, R ₂ is a linear or branched alkylene group having 1 to 20 carbon atoms, R ₃ is a straight or branched alkylene group having 1 to 20 carbon atoms or a straight or branched arylalkyl having 7 to 20 carbon atoms. It's Rengi.
The method of claim 1,
Polyether-based segment of the copolymer is a tire innerliner film comprising a repeating unit of the following formula (3):
[Formula 3]

In Formula 3,
R ₅ is a linear or branched alkylene group having 1 to 10 carbon atoms, n is an integer of 1 to 100,
R ₆ and R ₇ may be the same or different from each other and are a direct bond, -O-, -NH-, -COO- or -CONH-, respectively.
The method of claim 1,
The copolymer is a tire inner liner film comprising a polyamide-based segment and a polyether-based segment in a weight ratio of 6: 4 to 3: 7.
The method of claim 1,
In the base film layer, the polyamide-based resin and copolymer is a tire inner liner film is included in a weight ratio of 6: 4 to 3: 7.
The method of claim 1,
The thickness of the base film layer is 30 to 300 ㎛,
The film for tire innerliner whose thickness of the said contact bonding layer is 0.1-20 micrometers.
The method of claim 1,
The film for tire innerliner whose said base film layer is an unstretched film.
The method of claim 1,
The resorcinol-formalin-latex (RFL) -based adhesive may include 2 to 30% by weight of a condensate of resorcinol and formaldehyde; And 68 to 98% by weight of latex.
The method of claim 1,
The polymer film included in the release film layer includes one or more selected from the group consisting of polyolefin resin and polyester resin, Film for tire inner liner.
The method of claim 1,
The film for tire innerliner, wherein the release film layer has a thickness of 5 um to 50 um.
The method of claim 1,
The film for tire innerliner whose said base film is an unstretched film.
Melting and extruding a mixture between the polyamide-based resin and the copolymer including the polyamide-based segment and the polyether-based segment at 230 to 300 ° C. to form a base film layer;
Forming an adhesive layer including a resorcinol-formalin-latex (RFL) adhesive on at least one surface of the base film layer; And
Forming a release film layer including a polymer film having an initial modulus of 1500 Mpa or more at room temperature on the adhesive layer;
The content of the polyether-based segment contained in the copolymer is 15 to 50% by weight based on the total weight of the base film layer, a method for producing a film for tire innerliner.
17. The method of claim 16,
Forming the base film layer is a method for producing a film for tire innerliner comprising the step of extruding the mixture into a film of 30 to 300 ㎛ thickness.
17. The method of claim 16,
Forming the base film layer is a method for producing a film for tire innerliner comprising the step of mixing the polyamide-based resin and the copolymer in a weight ratio of 6: 4 to 3: 7.
17. The method of claim 16,
The copolymer includes a polyamide-based segment and a polyether-based segment in a weight ratio of 6: 4 to 3: 7.
17. The method of claim 16,
Forming the adhesive layer, 2 to 30% by weight of a condensate of resorcinol and formaldehyde; And applying an adhesive comprising latex 68 to 98% by weight on at least one surface of the base film layer to a thickness of 0.1 to 20 μm.
17. The method of claim 16,
And solidifying the base film layer formed by melting and extruding in a cooling unit maintained at 5 to 40 ° C.
17. The method of claim 16,
Forming the release film layer,
Applying at least one polymer selected from the group consisting of a polyolefin resin and a polyester resin on the adhesive layer to form a release film layer having a thickness of 5 um to 50 um; or
Comprising: laminating a film comprising at least one polymer selected from the group consisting of polyolefin resin and polyester resin on the adhesive layer to form a release film layer of a thickness of 5 um to 50 um; comprising, for the tire inner liner Method for producing a film.

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