KR20120002478A - Film for tire inner-liner and preparation method thereof - Google Patents

Abstract

PURPOSE: A film for inner-liner is provided to embody excellent airtighness with a thin thickness, thereby reducing the weight of tire and improving the gas mileage of a vehicle. CONSTITUTION: A film for inner-liner comprises an adhesive layer including and a substrate film with 30-300 micron thickness. The maximum load deflection rate(��) of the film for tire inner-liner and a substrate film, when elongation at room temperature, is 3-30%. The substrate film comprises 50-95wt% polyamide resin, and the copolymer or the mixture of a polyether resin. The adhesive contains 2-32wt% resorcinol, the condensate of formaldehyde, and 68-98wt% latex.

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 of manufacturing the same, and more particularly, to realize excellent airtightness even at a thin thickness, to enable the reduction of tire weight and the improvement of automobile fuel economy, and firmly coupled to the tire carcass layer. The present invention relates to a film for a tire innerliner and a method for manufacturing the same, which may be excellent in formability and fatigue resistance.

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 in contact with the road surface. It should provide the necessary frictional force for braking and driving, has good abrasion resistance, can withstand external shocks and has low heat generation.

Body Ply (or Carcass, 6): This is 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, most of them are made of steel wires 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 portion of the shoulder (2) from 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 hexagonal wire bundle with rubber coating on the wire that seats 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): This is a triangular rubber filler 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, 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 a result, the total weight of the tire is increased and the fuel economy of the car is reduced. Also, a phenomenon occurs in which air pockets are formed between the inner rubber and the inner liner of the carcass layer or the shape or properties of the inner liner are changed during the vulcanization process or the driving of the car. appear.

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, any previously known method has had a limit in maintaining excellent air permeability and tire formability while sufficiently reducing the thickness and weight of the inner liner, and additional tie gum rubbers for firmly bonding to the carcass layer inside the tire. There was a problem that increases the weight of the tire and lowers the fuel economy of the car. 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.

Accordingly, the development of a thinner innerliner having a thinner thickness and being easily coupled to the inside of the tire to reduce the weight of the tire and having sufficient fatigue resistance to withstand repeated deformation and physical properties such as excellent air tightness and formability It is required.

The present invention implements excellent airtightness even at a thin thickness to enable the weight reduction of the tire and the improvement of automobile fuel economy, and can be firmly coupled to the tire carcass layer, and the tire inner can exhibit excellent formability and fatigue resistance characteristics. It is for providing a film for liner.

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

The present invention is a 30 to 300 ㎛ thickness base film comprising a copolymer or mixture of 50 to 95% by weight of polyamide resin and 5 to 50% by weight of polyether resin; And an adhesive layer comprising an adhesive containing 2 to 32% by weight of a condensate of resorcinol and formaldehyde and 68 to 98% by weight of latex, wherein the maximum load deviation of the entire film and the base film at 100% elongation is increased. It provides a film for tire innerliner which is 3% to 30%.

In addition, the present invention comprises the steps of forming a copolymer or mixture of 50 to 95% by weight of a polyamide resin and 5 to 50% by weight of a polyether resin; Melting and extruding the copolymer or mixture to form a base film having a thickness of 30 to 300 μm; And forming an adhesive layer on the at least one surface of the base film layer, the adhesive layer comprising an adhesive containing 2 to 32% by weight of condensate of resorcinol and formaldehyde and 68 to 98% by weight of latex. The manufacturing method of the film for liners is provided.

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

According to one embodiment of the invention, 30 to 300 ㎛ thick substrate film comprising a copolymer or mixture of 50 to 95% by weight of polyamide resin and 5 to 50% by weight of polyether resin; And an adhesive layer comprising an adhesive containing 2 to 32% by weight of a condensate of resorcinol and formaldehyde and 68 to 98% by weight of a latex, wherein the tire inner is 100% elongated at room temperature according to the following general formula (1). A film for tire innerliner having a maximum load variation ratio DELTA M of the liner film and the base film may be 3% to 30%.

[Formula 1]

ΔM = {(M _ab -M _b ) / M _b } * 100

In the general formula 1, Mab is the maximum load appearing when the film for the tire inner liner 100% at room temperature, Mb is the maximum load appears when the base film is 100% stretching at room temperature.

As a result of the researches of the present inventors, using a base film prepared by copolymerizing or mixing a polyamide-based resin and a polyether-based resin in a specific content, it is possible to realize excellent airtightness and high air pressure retention performance even at a thin thickness. In addition, the base film exhibits high reactivity with a certain adhesive, so that even a thin and lightweight adhesive layer can be firmly and uniformly bonded to the inside of the tire, and easily stretched or deformed even when a small force is applied when the tire is formed. It has been found that it can be exhibited excellent molding properties and improved fatigue resistance properties.

In addition, the base film may have high reactivity with the resorcinol-formalin-latex (RFL) -based adhesive having the specific composition due to the characteristic chemical structure, and the resorcinol-formalin-latex (RFL) having the specific composition. The adhesive can exhibit high and uniform adhesion to the tire carcass layer. Accordingly, the tire inner liner film may be firmly and uniformly fixed or combined with respect to the tire carcass layer, and is a tire manufacturing process to which a high temperature deformation or stretching step is applied. In the process, the bonding force between the inner liner film and the tire carcass layer may be greatly reduced, or the phenomenon of breaking 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.

The 'copolymer of polyamide-based resin and polyether-based resin' is a block-like air in which a polyamide-based resin in which polyamide-based repeating units are collected and a polyether-based resin in which polyether-based repeating units are collected are copolymerized with each other. As well as coalescing, polyamide-based repeating units and polyether-based repeating units can encompass any type of random copolymer in which any repeating number and order are combined. For example, such a random copolymer may be obtained by copolymerizing monomers or precursors of the polyamide resin and monomers or precursors of the polyether resin, for example, monomers or oligomers for their preparation.

On the other hand, the tire inner liner film has a deviation ratio of the maximum load occurring in the tire inner liner film and the base film when it is stretched 100% at room temperature is 3% to 30%, preferably 5% to 35%, more Preferably from 10% to 30%. As such, the maximum load deviation ratio of the tire innerliner film and the base film at 100% elongation at room temperature may be represented by the following general formula (1).

[Formula 1]

ΔM = {(M _ab -M _b ) / M _b } * 100

In the general formula 1, M _ab is the maximum load appearing when the film for tire innerliner 100% elongation at room temperature, M _b is the maximum load appearing when the base film is 100% elongation at room temperature.

The difference between the maximum load at 100% elongation of the tire innerliner film including the base film and the adhesive layer and the maximum load at 100% elongation of the base film means the maximum load at 100% elongation of the adhesive layer directly or indirectly. can do. Accordingly, after the adhesive and the adhesive treatment process, the difference between the maximum load (Mab) when the film for the tire innerliner is stretched 100% at room temperature and the maximum load (Mb) when the base film is stretched 100% at room temperature is used. Based on the deviation ratio (ΔM) of the general formula (1) based on the characteristics related to the 'maximum load appearing in the adhesive layer at 100% elongation at room temperature' can be derived.

In the general formula 1, 'the maximum load (Mab) appearing in the tire inner liner film at 100% elongation at room temperature' is for the tire inner liner solidified under constant heat treatment conditions after applying the adhesive on one or both sides of the base film. It means the maximum load value that appears when the film is stretched 100% at room temperature. The 'constant heat treatment' is a specific example of a step that can be applied after treating the adhesive to the base film, it may be a step for bonding the adhesive layer with the base film or drying or solidifying the applied adhesive to form an adhesive layer, For example, it may be made for a time of about 10 seconds to 10 minutes at 100 to 200 ℃, more specifically may be a step of heat treatment for 1 minute at 150 ℃.

In the film for tire inner liner, the maximum load deviation ratio (ΔM) (hereinafter referred to as 'deviation ratio (ΔM) of general formula 1') of the tire inner liner film and the base film at 100% elongation at room temperature is 3 As shown in the range of% to 40%, both the base film and the adhesive layer can be uniformly elongated and deformed even when a small force is applied during the molding of the tire, so that the green tire or The moldability of the final tire can be improved, and the bond between the base film and the adhesive layer and the adhesive layer and the tire carcass layer can be maintained firmly.

On the other hand, the adhesive used in the film for the tire inner liner expresses the adhesive force by the cross-linking reaction and due to the characteristic that the maximum load that appears when 100% elongated may increase the deviation ratio (ΔM) of the general formula (1) Above, for example, only 3% or more can ensure a sufficient adhesive force. When the deviation ratio (ΔM) of the general formula 1 is 3% or more, the adhesive layer may exhibit a high degree of crosslinking when combined with the rubber of the base film or the carcass layer, thereby realizing excellent adhesive force, and thus the tire inner The film for the liner may be firmly bonded to the carcass layer.

In addition, the film for the tire inner liner is excellent in tires because the modulus of the film does not change significantly even after performing the adhesive layer forming process on the base film, for example, after solidifying under heat treatment conditions at 150 ° C. for 1 minute after applying the adhesive. Moldability and durability can be imparted. Accordingly, the film for the tire inner liner has to have a deviation ratio △ M of the general formula 1 below a predetermined level, for example, 40% or less, so that even if a small force is applied when the tire is formed, it may be suitable for the shape of the tire. It may be elongated or deformed, and may effectively prevent crystallization, cracking, or hardening due to heat or mechanical deformation generated during tire manufacturing or driving of a vehicle.

On the other hand, the maximum load that appears when the tire innerliner film 100% stretch may be 1.0 to 4.0 Kgf, preferably 1.3 to 3.5 Kgf. As the maximum load of the above-described range occurs when the tire inner liner film is 100% elongated at room temperature, the tire inner liner film may be stretched or deformed according to the shape of the tire even when a very small force is applied. Alternatively, crystallization, cracking, or hardening due to heat or mechanical deformation generated during a vehicle driving process may be effectively prevented. As described above, the tire inner liner film may be obtained by applying an adhesive to one surface or both surfaces of the base film and then solidifying under constant heat treatment conditions.

On the other hand, some of the main characteristics of the film for the tire inner liner is due to applying the base film obtained by copolymerizing or mixing a polyether-based resin imparting elastomeric properties with the polyamide-based resin in a specific content range. see.

In the base film, the portion derived from the polyamide-based resin exhibits excellent airtightness due to its inherent molecular chain properties, for example, about 10 to 20 times higher than that of butyl rubber or the like generally used for tires at the same thickness. The modulus is not so high compared to other resins. In addition, due to the portion derived from the polyester resin, the modulus characteristics of the entire base film may be lowered, and thus, may exhibit excellent moldability in a tire manufacturing process, and the film for the innerliner may be a film layer under high temperature and high pressure. It is possible to prevent the increase in the rigidity of or lower the mechanical properties.

In general, polyamide-based resins are known to be easily crystallized by heat, but the tire innerliner film may contain the polyether-based resin in a specific content to suppress crystal growth due to heat or external deformation in the film. Can be. Accordingly, the inner liner film is not easily crystallized by heat generated inside the tire, and the modulus or stiffness does not change significantly even by long-term driving, and it is possible to minimize cracks that may occur during driving.

On the other hand, the base film 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.

In addition, as shown in Figure 2, the base film can implement an excellent airtightness even at a lower thickness than the previous film for innerliner. Specifically, the base film may realize high airtightness even with the same thickness as the inner liner using halobutyl rubber, which is generally used, and may exhibit excellent airtightness as compared with the inner liner using natural rubber. In addition, although the general nylon 6 stretched film may exhibit high airtightness, the physical properties may be reduced or deformed during tire manufacturing or automatic driving, whereas the film for tire innerliner including the base film may provide excellent airtightness. Changes in physical properties or form are insignificant and the formability of the tire can be improved. In Figure 2, the horizontal axis is the thickness of the log scale film, the vertical axis is the air permeability (OTR), NR is a natural rubber, nylon film (Nnylon Film) is a common nylon 6 stretched film, innerliner rubber (Innerliner Rubber) # 1 and # 2 Denotes a tire inner liner using an halo butyl rubber, and an inner liner film (Innerliner Film) means a film for a tire inner liner as an example of the invention.

The base film may include a copolymer of 50 to 95% by weight of polyamide-based resin and 5 to 50% by weight of polyether-based resin, and 50 to 95% by weight of polyamide-based resin and 5 to 50% of polyether-based resin. It may comprise a weight percent mixture and may include both such copolymers and mixtures.

Since the polyamide-based resin can be used to exhibit excellent airtightness, the base film has a thin thickness and has a role of having low air permeability. In addition, since the portion derived from such a polyamide-based resin exhibits a modulus that is not relatively higher than that of other resins, even when mixed or copolymerized with a relatively low content of polyether-based resin or the like, a low range of a specific range may be achieved by a method described below. The film for innerliner showing a modulus can be obtained, and the moldability of a tire can be improved by this.

Also, Since the portion derived from the polyamide-based resin has sufficient heat resistance and chemical stability, it is possible to prevent the innerliner film 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, since the portion derived from the polyamide-based resin may have a relatively high reactivity with a certain adhesive, for example, a resorcinol-formalin-latex (RFL) adhesive, the film for the innerliner is carcass. It can be easily adhered to the part, it is possible to prevent the breakage of the interface due to heat or repeated deformation occurring during the manufacturing process or running process of the tire, so that the inner liner film can have sufficient fatigue resistance.

As a component of the copolymer or the mixture, the polyamide-based resin may be included in 50 to 95% by weight, preferably 70 to 90% by weight. When the polyamide-based resin is contained in less than 50% by weight, the density or airtightness of the base film may be lowered. When the polyamide-based resin is included in an amount of more than 95% by weight, the modulus of the base film may be excessively high or the moldability of the tire may be deteriorated. Amide-based resins may crystallize and cracks may occur due to repeated deformation.

Examples of the polyamide resin that can be used for the base film include polyamide resins such as nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66 copolymers, 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.

Meanwhile, the precursor of the polyamide-based resin may be used in the process of forming the copolymer or mixture of the polyamide-based resin and the polyether-based resin. As a precursor of such a polyamide-type resin, the monomer known to be used for the synthesis | combination of the polyamide-type resin mentioned above, or its oligomerization is mentioned. For example, when the polyamide-based resin is nylon 6, ε-caprolactam can be used as its precursor.

Such polyamide-based resins may have a relative viscosity of 2.5 to 4.0. When the relative viscosity is less than 2.5, sufficient elongation may not be secured due to a decrease in toughness, and damage may occur when manufacturing a tire or driving a vehicle. When the relative viscosity is greater than 4.0, modulus or viscosity is unnecessarily high, thereby increasing the efficiency and efficiency of the manufacturing process. Economics may be lowered.

On the other hand, the portion derived from the polyether-based resin may be present in a bonded or dispersed state between the polyamide-based resins, to suppress the growth of large crystals in the base film during the tire manufacturing process or driving of the vehicle or The base film can be easily prevented from being broken. In addition, the portion derived from such a polyether-based resin can lower the modulus of the film for the tire inner liner, thereby allowing it to be stretched or deformed to conform to the shape of the tire even when a very small force is applied during tire forming. It is possible to easily mold the tire. And, the portion derived from such a polyether resin can suppress the increase in the rigidity of the film at low temperature, can prevent damage or tearing of the inner liner film due to crystallization or repeated deformation at high temperature, and the inner liner By improving the resilience to the deformation of the suppression of wrinkles generated by the film due to permanent deformation can improve the durability of the tire or innerliner.

As a component of the copolymer or the mixture, the polyether resin may be included in 5 to 50% by weight, preferably 10 to 30% by weight. When the polyether-based resin is included in less than 5% by weight, the modulus of the base film or the tire innerliner film may be increased, thereby deteriorating the moldability of the tire or significantly reducing the physical properties due to repeated deformation. In addition, when the polyether-based resin is contained in excess of 50% by weight, the airtightness of the film for the tire inner liner may be lowered, and the reactivity to the adhesive is lowered, so that the inner liner easily adheres to the carcass layer. The following may be difficult, and the elasticity of the base film may be increased, and thus it may not be easy to prepare a uniform film.

As a polyether resin which can be used for the said base film, polyethyleneglycol, polypropylene glycol, polytetramethylene glycol, polyoxyethylene diamine, polyoxypropylene diamine, polyoxytetramethylene diamine, or a copolymer thereof is used alone or It can be mixed and used. The weight average molecular weight of the polyether resin may be 500 to 10,000, preferably 1,000 to 3,000. When the weight average molecular weight is less than 500, the polyether resin may not appropriately inhibit the growth of large crystals in the tire inner liner film or lower the modulus. In addition, when the weight average molecular weight is more than 10,000, the airtightness of the inner liner may be reduced.

In addition, the precursor of the polyether-based resin may be used in the process of forming the copolymer or mixture of the polyamide-based resin and the polyether-based resin. As a precursor of such a polyether resin, the monomer known to be used for the synthesis | combination of the polyether resin mentioned above, or its oligomer is mentioned. For example, when the polyether-based resin is polyethylene glycol, ethylene glycol or oligomerization of ethylene glycol may be used as a precursor thereof, and in the case of polyoxyethylene diamine, ethylene glycol, ethylene glycol diamine or ethylene glycol diamine may be used as a precursor thereof. Oligomerized products of the like and the like can be used.

On the other hand, the base film may be an unstretched film. When the base film is an unstretched film, it has a low modulus and a high strain rate and can be suitably applied to a tire forming step 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 for manufacturing the tire innerliner film described below, a method of suppressing the orientation of the base film as much as possible, for example, viscosity adjustment through optimizing the melt extrusion temperature, changing the die die specification, or adjusting the winding speed, etc. Through this method, the base film can be prepared into an unoriented or unoriented film.

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.

On the other hand, 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 main characteristics of the above-described adhesive layer appears to include a specific resorcinol-formalin-latex (RFL) -based adhesive having a specific composition. In the past, an adhesive for tire innerliner was used, such as a rubber type tie gum, and 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. In addition, the base film and the tire carcass layer may be firmly bonded by pressing at high temperature heating conditions without increasing the thickness. 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 adhesive is capable of crosslinking between latex and rubber, thereby exhibiting adhesive performance. 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, not only sufficient adhesion performance can be realized, but also the deviation ratio (ΔM) of the general formula 1 is in an appropriate range, for example. For example, it can be maintained at 3% to 30% to improve the formability of the green tire or the final tire.

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 20 μm or less, for example, 0.1 to 10 μm, preferably 0.2 to 7 μm, more preferably 0.3 to 5 μm, and one or both surfaces of the film for tire innerliner. It can be formed on. 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 may have an adhesive force of 15 to 40 kgf with respect to the tire carcass layer. This adhesion can be measured by the ASTM D 4394 method. In addition, the standard deviation of the adhesive force to the tire carcass layer of the tire inner liner film may be 5 or less, preferably 3 or less. Accordingly, the tire inner liner film may be very uniformly and firmly bonded to the tire carcass layer.

The tire carcass layer (or body ply) refers to a structure in which a tire cord is included in a certain rubber component as a skeleton of a tire supporting a load of a vehicle body, and in general, the rubber component of the tire carcass layer is a tire inner liner. Combined with. The rubber component used in the carcass layer may be included without any limitation as long as it is a conventionally known material, and may include, for example, 30% by weight or more of synthetic rubber or natural rubber, and various other additives. have. As the tire cord included in the carcass layer, various natural fibers or rayon, nylon, polyester, kevlar, or the like may be used, and a steel cord braided with a thin wire may also be used.

The tire inner liner film has a thinner thickness than the previously known inner liner film, but has low air permeability, for example, 200 cc / (m 2 · 24hr · atm) or less, preferably 180 cc / (m 2. 24 hr · atm) or 0 to 180 cc / (m 2 · 24 hr · atm) of oxygen permeability.

In addition, the tire inner liner film can maintain a 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]

On the other hand, the base film, a polyamide (poly-amide) segment; And only copolymers comprising 5 to 50% by weight of poly-ether based segments with respect to the total weight of the film.

Accordingly, the inner liner film can be distinguished from the previous tire inner liner film whose main component is a rubber-based component or a thermoplastic resin component, and does not require an additional vulcanizer. May have characteristics. The base material of the film means a substrate of a resin or rubber component that maintains the shape of the film except for an additional dispersion component such as an additive in a tire inner liner film. The base material often contained various rubber components or resin components. By the way, the tire inner liner film according to an embodiment of the invention may include a polyamide-based resin, etc. together with the copolymer as a base material, but may also include only the copolymer, in this case other resin or rubber component It may not substantially include.

The polyamide-based segment may be a main repeating unit included in the polyamide-based resin described above. Specifically, the polyamide-based segment may include a repeating unit of Formula 1 or Formula 2.

[Formula 1]

In Formula 1, R ₁ may be a straight or branched chain alkylene group having 1 to 20 carbon atoms or a straight or branched chain 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 may be a Rengi.

In this specification, an alkylene group means a divalent functional group derived from an alkyl group, and an arylalkylene group means a divalent functional group derived from an alkyl group into which an aryl group is introduced. .

The polyether segment may be a main repeating unit included in the aforementioned polyether resin. The polyether segment refers to a repeating unit including an alkyl oxide ('-Akyl-O-') group, and may be formed from a polyether resin or a precursor thereof that participates in a polymerization reaction. Specifically, the polyether segment may include a repeating unit of Formula 5 below.

[Formula 5]

In Formula 5, R ₅ may be a linear or branched alkylene group having 1 to 10 carbon atoms, n may be an integer of 1 to 100. In addition, R ₆ and R ₇ may be the same as or different from each other, and may be a direct bond, -O-, -NH-, -COO- or -CONH-, respectively.

The tire innerliner film may further include a polyamide-based resin in order to improve mechanical properties or airtightness. Such polyamide-based resin may be present on the film in a mixed state or copolymerized state with the copolymer of the polyamide-based segment and the polyether-based segment described above. As shown in the manufacturing method described below, the polyamide-based resin may be included in the tire innerliner film by being melted and extruded after being mixed with a copolymer of the polyamide-based segment and the polyether-based segment.

The polyamide-based resin that may be further included may be used to improve the mechanical properties of the film for the tire inner liner, for example, heat resistance or chemical stability, and airtightness, but the tire inner liner manufactured when the amount used is too large The characteristic of the film for resin can be reduced. In particular, even when the polyamide-based resin is further used, the total of the polyether-based segment or the polyamide-based resin in the film should be maintained at 5 to 50% by weight, and thus, the polyamide-based resin, The sum of the contents of the polyamide-based segment and other additives and the like should be 50 to 95% by weight.

The additionally usable polyamide-based resin is not particularly limited, and in order to increase compatibility with the copolymer, it is preferable to use a polyamide-based resin including the same or similar repeating units as the polyamide-based segment. .

On the other hand, according to another embodiment of the invention, forming a copolymer or mixture of 50 to 95% by weight of polyamide-based resin and 5 to 50% by weight of polyether-based resin; Melting and extruding the copolymer or mixture to form a base film having a thickness of 30 to 300 μm; And forming an adhesive layer comprising an adhesive containing at least one surface of the condensate of resorcinol and formaldehyde and at least one surface of the base film layer, wherein the adhesive layer comprises from 2 to 32% by weight of condensate and from 68 to 98% by weight of latex. The manufacturing method of the film for 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 base film may have high reactivity with the resorcinol-formalin-latex (RFL) -based adhesive having the specific composition due to the characteristic chemical structure, and the resorcinol-formalin-latex (RFL) having the specific composition. The adhesive can exhibit high and uniform adhesion to the tire carcass layer, and is a tire manufacturing process in which a high temperature deformation or stretching step is applied. The breakage phenomenon between the inner layers can be prevented.

As described above, the tire inner liner film has a deviation rate (deviation ratio of the general formula 1, ΔM) generated by the tire inner liner film and the base film when the film is 100% elongated at room temperature. It may be 3% to 30%, preferably 5% to 35%, more preferably 10% to 30%, and specific details thereof are as described above. In addition, the maximum load that appears when the tire innerliner film is 100% elongated at room temperature may be 1.0 to 4.0 Kgf, and details related thereto are as described above.

In addition, the tire inner liner film may have an adhesive force of 15 to 40 kgf on the tire carcass layer measured by the ASTM D 4394 method, and the air permeability measured by the method of ASTM D 3895 is 200 cc / (㎡ · 24hr Atm) or less. Specific contents related to these are as described above.

Forming the copolymer or mixture of the 50 to 95% by weight of the polyamide resin and 5 to 50% by weight of the polyether resin, 50 to 95% by weight of the polyamide resin or precursor thereof and the polyether resin or It may include the step of polymerizing or mixing 5 to 50% by weight of the precursor.

And, forming the copolymer or mixture may change the reaction conditions according to the specific type of the resin or precursor to be used. For example, in the step of reacting a monomer of a polyamide-based resin (eg, ε-caprolactam, etc.), acidic conditions and a nitrogen atmosphere may be applied, and the polyamide-based resin or a precursor thereof; And polymerizing the polyether-based resin may include heating or melting at a temperature of 50 ° C. or more, and may include increasing or reducing the pressure according to the reaction step.

Meanwhile, various mixing, blending, or compounding methods known to be usable for mixing the polymer resin may be used for mixing the polyamide-based resin or the precursor thereof and the polyether-based resin or the precursor thereof without any particular limitation. In addition, the polymerization reaction of the polyamide-based resin or precursors thereof and polyether-based resins or precursors thereof may be used without any limitation. .

The details of the polyamide-based resin or precursor thereof and the polyether-based resin or precursor thereof are as described above.

The temperature at which the polyamide-based resin or precursor thereof and the copolymer or mixture of the polyether-based resin or the precursor thereof is melted may be 230 to 300 ° C, preferably 240 to 280 ° C. 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.

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 the unstretched film, a method of optimizing the melt extrusion temperature to adjust the viscosity of the melt, adjusting the discharge amount of the melt, changing the specification of the die, or adjusting the winding speed of the film can be used. have.

For example, the lip opening of the die can be set around 1 mm, and making the lip opening too narrow is undesirable because the pressure on the die shear can be too high. In addition, 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, to suppress the winding speed as much as possible to achieve a speed of 100 m / min or less, preferably 50 m / min or less Applicable

In addition, the method for producing a film for tire innerliner may include forming an adhesive layer including a resorcinol-formalin-latex (RFL) -based adhesive on at least one surface of the film after forming the film step through melt extrusion. It may further include.

The forming of the adhesive layer may be performed by coating a resorcinol-formalin-latex (RFL) adhesive on one or both surfaces of the formed base film, and then drying the adhesive layer. May have a thickness of preferably 0.1 to 10 μm. 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.

Meanwhile, in the forming of the copolymer or the 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.

According to the present invention, it is possible to realize excellent airtightness even at a thin thickness, to reduce the weight of the tire and improve the fuel economy of the vehicle, to be firmly coupled to the tire carcass layer, and to exhibit excellent formability and fatigue resistance characteristics. A film for tire innerliner may be provided.

1 schematically shows the structure of a tire.
Figure 2 schematically shows the air permeability according to the material and thickness of the inner liner.

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.

* In the following Examples and Comparative Examples, the thickness of the base film was measured using a gauge tester (MITSUSTOYO Co., Ltd.), and the thickness of the adhesive layer was measured five times using the FE-SEM device (JEOL Co., Ltd.) of the cross section of the tire inner liner film. It was set as the average value of the obtained result.

< Example : tire For inner liner  Manufacturing of Film>

One. Example  One

(1) Production of base film

60% by weight of polyamide-based resin (nylon 6) having a relative viscosity of 3.4 and 40% by weight of polyamide-based elastomer resin (copolymer resin using 50% by weight of nylon 6 and polyoxyethylene glycol, respectively) having a weight average molecular weight of 100,000 Then, the substrate was extruded into an annular die at 260 ° C. to prepare an unstretched base film having a thickness of 80 μm at a rate of 30 m / min without undergoing stretching and heat treatment.

(2) Preparation of Adhesive Layer Composition

Resorcinol and formaldehyde were mixed in a molar ratio of 1: 2, and then condensed to obtain a condensate of resorcinol and formaldehyde.

12% by weight of the condensate of resorcinol and formaldehyde and 88% by weight of styrene / 1,3-butadiene / vinylpyridine latex were mixed to obtain a mixture of lesosinol / formaldehyde-latex with a concentration of 20%.

(3) Manufacture of tire innerliner film

The resorcinol-formalin-latex (RFL) adhesive layer composition was applied to both surfaces of the substrate film (200 mm x 300 mm) using a gravure coater, respectively. Then, the film was dried and heat treated at 150 ° C. in a hot air oven for 60 seconds to prepare a film for tire innerliner having an adhesive layer having a thickness of 1.0 μm formed on both sides of the base film.

2. Example  2

In the manufacturing process of the base film, the film for tire innerliners was manufactured by the same method as Example 1 except having used the component of a polyamide-type resin and a polyamide-type elastomer resin at 50 weight% and 50 weight%, respectively. .

3. Example  3

In the adhesive layer composition, the condensate of resorcinol and formaldehyde and the content of styrene / butadiene-1,3 / vinylpyridine latex were varied to 13 wt% and 87 wt%, respectively, and the adhesive layer was formed to a thickness of 1.2 μm. Except for the tire innerliner film was prepared in the same manner as in Example 1.

4. Example  4

In the adhesive layer composition, the content of the condensate of resorcinol and formaldehyde and the content of styrene / butadiene-1,3 / vinylpyridine latex were varied to 15% by weight and 85% by weight, respectively, A tire inner liner film was manufactured in the same manner as in Example 1 except that the concentration was changed to 25% and the adhesive layer was formed to a thickness of 1.4 μm.

5. Example  5

A film for tire innerliner was prepared in the same manner as in Example 1 except that the concentration of the mixture of resorcinol / formaldehyde-latex was changed to 25% and the adhesive layer was formed to a thickness of 1.6 μm.

6. Example  6

(1) Production of base film

To a mixture of 70 wt% of ε-caprolactam and 30 wt% of polyoxyethylene diamine (Mw 1000) for resin polymerization for the base film, mix mole number adipic acid such as polyoxyethylene diamine, It melt | dissolved for 30 minutes in nitrogen atmosphere of 100 degreeC. The melt was heated at 250 ° C. for 3 hours and elevated to 8 kg / cm 2 to maintain pressure. Then, the pressure was reduced to 1 kg / cm 2 for 1 hour.

After the pressure-sensitive melt was prepared in a chip shape, the prepared chip was extruded into an annular die at a temperature of 260 ° C. to obtain a 100 탆 thick unstretched substrate film at a speed of 30 m / min without undergoing a stretching and heat treatment section.

(2) Preparation of Adhesive Layer Composition

Resorcinol and formaldehyde were mixed in a molar ratio of 1: 2, and then condensed 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 mixture of lesosinol / formaldehyde-latex with a concentration of 20%.

(3) Manufacture of tire innerliner film

The resorcinol-formalin-latex (RFL) adhesive layer composition was applied to both surfaces of the substrate film (200 × 300 mm) using a gravure coater, respectively. Subsequently, a film for tire innerliner having a 0.5 μm thick adhesive layer formed on both sides of the base film was dried and heat-treated at 150 ° C. for 60 seconds.

7. Example  7

In the manufacturing process of the base film, the film for tire innerliners was manufactured by the same method as Example 6 except having used the mixture of 60 weight% of epsilon caprolactam and 40 weight% of polyoxyethylene diamine (Mw 1,000). It was.

8. Example  8

In the manufacturing process of the base film, the film for tire innerliner was manufactured by the same method as Example 6 except having used the mixture of 80 weight% of epsilon caprolactam and 20 weight% of polyoxyethylene diamine (Mw 1,000). It was.

9. Example  9

In the adhesive layer composition, the content of the condensate of resorcinol and formaldehyde and the content of styrene / butadiene-1,3 / vinylpyridine latex were changed to 15 wt% and 85 wt%, respectively, and the adhesive layer was formed to a thickness of 0.6 μm. Except for the tire innerliner film was prepared in the same manner as in Example 6.

10. Example  10

In the adhesive layer composition, the content of the condensate of resorcinol and formaldehyde and the content of styrene / butadiene-1,3 / vinylpyridine latex were varied to 17 wt% and 83 wt%, respectively, and the adhesive layer was formed to a thickness of 0.7 μm. Except for the tire innerliner film was prepared in the same manner as in Example 6.

< Comparative example : tire For inner liner  Manufacturing of Film>

One. Comparative example  One

In the manufacturing process of the base film, except that the content of ε-caprolactam and polyoxyethylene diamine (Mw 1,000) is used at 97% by weight and 3% by weight, respectively, and the adhesive layer is formed to a thickness of 1.0㎛, A film for tire innerliner was prepared in the same manner as in Example 6.

2. Comparative example  2

In the manufacturing process of the base film, except that the content of ε-caprolactam and polyoxyethylene diamine (Mw 1,000) is used at 20% by weight and 80% by weight, respectively, and the adhesive layer is formed to a thickness of 1.2㎛, A film for tire innerliner was prepared in the same manner as in Example 6.

< Experimental Example : tire For inner liner  Measurement of Film Properties>

Experimental Example 1 . tire For inner liner  Measurement of the maximum load that occurs at 100% elongation of the film and base film, and Of formula 1 Deviation Rate  Measure

The maximum load value which appears when the base film obtained in the said Example and the comparative example and the film for tire innerliner were extended | stretched 100% in MD (Machine Direction) direction was measured. The maximum load value per unit thickness was obtained by dividing the measured maximum load value by the thickness of the film.

The specific measuring method is as follows.

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

(2) measurement conditions:

i) Head Speed 300 mm / min,

ii) grip distance 100 mm,

iii) Sample Width 10 mm,

iv) measured at 25 ° C. and 60 RH% atmosphere

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

The maximum load value obtained above was applied to the following general formula 1, and the maximum load deviation ratio (ΔM) between the film for tire innerliner and the base film at 100% elongation at normal temperature was obtained.

[Formula 1]

ΔM = {(Mab-Mb) / Mb} * 100

In the general formula 1, Mab is the maximum load appearing when the film for tire innerliner 100% elongation, Mb is the maximum load appearing when the base film 100% elongation. The results obtained above are shown in Table 1 below.

Results of Experimental Example 1 division Maximum load at 100% elongation of base film (M _b )
[kgf] Maximum load at 100% elongation of film for tire inner liner (M _ab )
[kgf] △ M
[%] Example 1 2.05 2.45 19.51 Example 2 1.37 1.60 16.79 Example 3 2.05 2.50 21.95 Example 4 2.05 2.53 23.41 Example 5 2.05 2.61 27.32 Example 6 1.88 2.15 14.36 Example 7 1.84 1.98 7.61 Example 8 2.28 2.56 12.28 Example 9 1.88 2.06 9.57 Example 10 1.88 2.18 15.96 Comparative Example 1 3.8 5.4 42.11 Comparative Example 2 0.86 0.94 9.30

As shown in Table 1, the maximum load at the time of 100% elongation of the film for tire innerliner of the above example is about 1.5 to 2.7 kgf, and the film for tire inner liner is 100% elongated at room temperature. The maximum load deviation rate (ΔM) of the base film was found to be 7.61% to 27.32%. That is, when the tire inner liner film is applied, even if a force is not applied to the tire in the tire forming process, it may be stretched or deformed according to the shape of the tire, and the characteristics of the adhesive layer of the tire inner liner film according to the embodiment Since a small load is applied during the deformation or stretching of the phase manufacturing process, the adhesive force between the adhesive layer and the carcass layer or the adhesive layer and the base film can be prevented from occurring or non-uniform adhesion can be prevented, and the final product is produced. The defect rate can be minimized.

On the contrary, in the case of the tire inner liner of Comparative Example 1, although the adhesive layer having the same thickness as in Examples 1 and 2, the variation ratio (ΔM) of the maximum load of the general formula 1 at 100% elongation was relatively large, resulting in tire production. There is a problem in that a large force must be applied in the deformation or stretching step of the process, and the moldability of the tire may be reduced or the defective rate of the final product may be increased. In addition, in the case of the tire inner liner of Comparative Example 2, the maximum load at 100% elongation is only 0.94 kgf, making it difficult to secure proper physical properties or the base film may be deformed or stretched more than necessary in the tire manufacturing process.

Experimental Example 2 . Air permeability experiment

The air permeability of the base film obtained in the said Example and the comparative example was measured by the Oxygen Permeation Analyzer (Model 8000, the product made by Illinois Instruments) by the method of ASTM D 3895 in 25 degree-60RH% atmosphere.

Experimental Example  3. Tire For inner liner  Adhesion of film Peel - Test ) Measure

The adhesive force to the tire carcass layer of the film for tire innerliner obtained in the above Examples and Comparative Examples was measured according to the American Material Testing Association standard ASTM D 4394 method.

Specifically, 1.6 mm rubber sheet, cord paper, the tire inner liner film, 1.6 mm rubber sheet, cord paper, 1.6 mm rubber sheet was laminated in this order, 150 ℃ at a pressure of 60 kg / cm ² Vulcanized at 30 minutes. Thereafter, the vulcanized sample was cut and cut to a width of 1 inch.

At this time, the 1.6 mm rubber sheet, cord paper, 1.6 mm rubber sheet to form a carcass layer, the rubber sheet was prepared using a rubber composition of the composition as shown in Table 2 below .

Composition of rubber sheet ingredient Content (parts by weight) caoutchouc 100 Zinc oxide 3 Carbon black 29.8 Stearic acid 2.0 Pin Tar 7.0 Mercaptobenzothiazole 1.25 sulfur 3.0 Diphenylguanidine 0.15 Phenylbetanaphthalamine 1.0 Sum 147.2

Then, the cut sample was peeled off at 25 ° C. at a rate of 300 mm / min using a universal testing machine (Instron Co., Ltd.) to measure the adhesive force (kgf) of the innerliner film to the carcass layer twice, and the average value thereof was measured. Obtained. At this time, the average value of the load which arises at the time of peeling was calculated by adhesive force.

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%. .

Experimental Example 5 . Air pressure retention performance measurement

The tires prepared in Experimental Example 4 were measured and compared for 90 days under the pressure of 101.3 kPa at 21 ° C. using the ASTM F1112-06 method, according to the following formula (IPR Internal Pressure Retention).

The results measured in Experimental Examples 2 and 5 are shown in Table 3 below.

Results of Experimental Examples 2 to 5 division Adhesion
(kgf) Air permeability
(cc / ㎡ * 24hr * atm) Green Tire
Ease of Formation Final tire
Appearance Evaluation 90 day air pressure retention rate (%) Example 1 26.0 150 Good Good 96.9 Example 2 22.4 165 Good Good 96.5 Example 3 27.6 148 Good Good 97.0 Example 4 28.0 140 Good Good 97.0 Example 5 31.4 130 Good Good 97.1 Example 6 24.0 111 Good Good 97.4 Example 7 22.7 145 Good Good 97.0 Example 8 26.0 95 Good Good 97.6 Example 9 26.5 108 Good Good 97.5 Example 10 26.4 102 Good Good 97.5 Comparative Example 1 13.0 58 Bad shape - - Comparative Example 2 15.8 457 Good Good 92.5

As shown in Table 3, the film for the tire innerliner of the embodiment was found to be more than 20kgf adhesive strength to the tire carcass layer measured by the American Society for Testing and Materials ASTM D 4394 method, accordingly, the tire inner of the embodiment It has been found that the liner film can be bonded very uniformly and firmly to the tire carcass layer. In addition, the film for tire innerliner of the embodiment exhibits air permeability of 200 cc / ㎡ * 24hr * atm or less to achieve excellent airtightness even in a thin thickness, and easily stretched or It was confirmed that the moldability of the green tire or the final tire can be deformed.

On the other hand, the film for tire inner liner of the comparative example was found to have a low adhesive force compared to the film for tire inner liner of the example because the adhesive force measured by the ASTM D 4394 method was 16 kgf or less.

In addition, although the film for tire innerliner of Comparative Example 2 has low air permeability, it is necessary to apply a great force when extending or deforming and insufficient stretching is easy, so that the shape of the green tire becomes poor or the inner liner inside the green tire. The film was torn or found to be impossible to produce.

In addition, the tire manufactured using the film for the tire inner liner of the embodiment has an internal pressure retention (IPR) measured for 90 days at 21 ° C. and 101.3 kPa according to the method of ASTM F1112-06. It can be found to be more than 95%, to prevent the overturn accident caused by low air pressure and lower fuel economy.

On the other hand, in the case of Comparative Example 2 green tire molding itself is difficult to measure the air pressure retention rate, it can be seen that in the case of Comparative Example 3 also the tire air pressure retention rate is significantly reduced to 92.5%.

As described above, the film for tire innerliner of the embodiment can be stretched or deformed to conform to the shape of the tire even when a very small force is applied during the molding of the tire, thereby enabling easier molding in the tire manufacturing process. On the contrary, in the case of the comparative example, even if the expansion pressure is applied, problems such as insufficient stretching and poor shape of the green tire, tearing of the inner liner film, or opening of the inner liner film connection part may occur. Even if it has a high air permeability, the low air pressure retention rate of the tire was found to be a problem that the final performance is lowered.

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

Claims (14)

50 to 95 wt% of a polyamide resin; And base material having a thickness of 30 to 300 ㎛ including a copolymer or a mixture of 5 to 50% by weight of a polyether resin; And
An adhesive layer comprising an adhesive containing 2 to 32% by weight of a condensate of resorcinol and formaldehyde and 68 to 98% by weight of a latex;
A tire inner liner film having a maximum load deviation ratio (ΔM) of 3% to 30% between the tire inner liner film and the base film at 100% elongation at room temperature according to the following general formula 1:
[Formula 1]
ΔM = {(M _ab -M _b ) / M _b } * 100
In the general formula 1,
Mab is the maximum load when the film for tire inner liner is stretched 100% at room temperature,
Mb is the maximum load which appears when the base film is stretched 100% at room temperature.
The method of claim 1,
The adhesive layer is formed on at least one surface of the base film, the film for tire innerliner having a thickness of 0.1 to 10 ㎛.
The method of claim 1,
A tire inner liner film having a maximum load of 1.0 to 4.0 Kgf when the tire inner liner film is stretched 100% at room temperature.
The method of claim 1,
The film for tire innerliner whose air permeability measured by the method of ASTMD 3895 is 200 cc / (m <2> * 24hr * atm) or less.
The method of claim 1,
The polyamide-based resin is nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 610, nylon 612, copolymer of nylon 6/66, nylon 6/66/610 copolymer, nylon MXD6, nylon 6T, Nylon 6 / 6T copolymer, nylon 66 / PP copolymer, nylon 66 / PPS copolymer, methoxymethylated 6-nylon, methoxymethylated 6-610-nylon and methoxymethylated 612-nylon Tire innerliner film comprising one or more selected from the group consisting of.
The method of claim 1,
The polyether resin is at least one selected from the group consisting of polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyoxyethylene diamine, polyoxypropylenediamine, polyoxytetramethylene diamine, and copolymers thereof. Film for tire innerliner to include.
The method of claim 1,
The film for tire innerliner whose said base film is an unstretched film.
The method of claim 1,
The condensation molar ratio of the resorcinol and formaldehyde is 1: 0.3 to 1: 3.0 film for tire innerliner.
The method of claim 1,
A film for tire innerliner having an adhesion of 15 to 40 kgf to the tire carcass layer measured by the ASTM D 4394 method.
Forming a copolymer or mixture of 50 to 95% by weight of polyamide-based resin and 5 to 50% by weight of polyether-based resin;
Melting and extruding the copolymer or mixture to form a base film having a thickness of 30 to 300 μm; And
The tire of claim 1 comprising forming an adhesive layer comprising an adhesive containing 2 to 32% by weight of a condensate of resorcinol and formaldehyde and 68 to 98% by weight of a latex on at least one surface of the base film layer. The manufacturing method of the film for innerliners.
The method of claim 10,
Forming the copolymer or mixture,
A method for producing a film for tire innerliner comprising the step of polymerizing or mixing 50 to 95% by weight of polyamide resin or precursor thereof and 5 to 50% by weight of polyether resin or precursor thereof.
The method of claim 10,
Melting and extruding the copolymer or mixture is carried out at 230 to 300 ℃ a method for producing a film for tire innerliner.
The method of claim 10,
The adhesive layer is a method for producing a film for tire innerliner having a thickness of 0.1 to 10 ㎛.
The method of claim 10,
The said base film is a manufacturing method for the film for tire innerliners whose unstretched film.

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