KR20190038147A - Tire inner liner laminated body - Google Patents

Abstract

The present invention relates to a tire inner liner laminate. The tire inner liner laminate comprises: a substrate film including a polyamide-based resin and a copolymer including a polyamide-based segment and a poly-ether-based segment; an adhesive layer formed on at least one surface of the substrate film and including a resorcinol-formalin-latex (RFL)-based adhesive; and an elastic layer formed on the adhesive layer and including at least one rubber selected from a group consisting of natural rubber and synthetic rubber.

Description

[0001] TIRE INNER LINER LAMINATED BODY [0002]

The present invention relates to a tire inner liner laminate, more particularly, to a tire inner liner laminate which exhibits uniform and excellent physical properties in all directions, has a relatively high tensile strength and impact strength and a low modulus, Which is capable of realizing excellent durability and endothelial characteristics with respect to a tire inner liner laminate.

The tire supports the load of the vehicle, mitigates the impact from the road surface, and transmits the driving force or braking force of the vehicle to the ground. Generally, a tire is a composite of a fiber / steel / rubber and has a structure as shown in Fig.

Tread (1): It is a part that comes into contact with the road surface, it should provide friction force necessary for braking and driving, good abrasion resistance, able to withstand external impact, and low heat generation.

Body Ply (or Carcass) (6): It is a coil layer inside the tire. It should support the load and resist the impact.

Belt (5): It is located between the body fly, and it is made of steel wire in most cases, it alleviates the external impact and keeps the ground surface of the tread wide to improve the running stability.

Side Wall (3): A rubber layer between the lower portion of the shoulder (2) and the bead (9), and protects the inner body ply (6).

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

BEAD (9): A square or hexagonal wire bundle with rubber coated wire to seat and fix the tire on the rim.

CAP PLY (4): It is a special cloth paper placed on the belt of the radial tires for some passenger cars, minimizing the movement of the belt when driving.

APEX (8): It is a triangular rubber filling material used to minimize the dispersion of beads, protect the beads by mitigating external impact, and prevent the inflow of air during molding.

In recent years, tube-less tires having high-pressure air of about 30 to 40 psi have been generally used without using a tube. In order to prevent the inner air from leaking to the outside during the operation of the vehicle An inner liner having high airtightness is disposed on the inner layer of the carcass.

Previously, a tire inner liner having rubber components such as butyl rubber or halobutyl rubber, which is relatively low in air permeability, was used. In this inner liner, the rubber content or the thickness of the inner liner had to be increased in order to obtain sufficient airtightness . However, when the content of the rubber component and the tire thickness are increased, the total weight of the tire is increased and the fuel economy of the automobile is lowered.

Accordingly, various methods have been proposed to reduce the thickness and weight of the inner liner to reduce fuel consumption, and to reduce changes in the form and physical properties of the inner liner that occur during the molding or running of the tire.

However, any previously known method has had a limitation in maintaining excellent air permeability and moldability of the tire while sufficiently reducing the thickness and weight of the inner liner. In addition, the inner liner obtained by the previously known method has a problem in that the properties of the inner liner itself deteriorate in the manufacturing process of the tire in which the high temperature repetitive molding is performed or the repeated process of deformation, .

Further, as air pockets are formed between the inner liner and the carcass layer during the tire manufacturing process or the inner liner and the carcass layer are unevenly adhered to each other, it is difficult to manufacture uniform tires, Problems such as peeling of the liner or occurrence of cracks on the inner liner have appeared.

The present invention relates to a rubber composition which exhibits uniform and excellent physical properties in all directions, has a relatively high tensile strength and impact strength, has a low modulus, is excellent in durability and endothelial characteristics against repeated deformation occurring during tire travel To provide a tire inner liner laminate.

In the present specification, a polyamide based resin; And a copolymer comprising a polyamide-based segment and a poly-ether-based segment; An adhesive layer formed on at least one side of the base film and including a resorcinol-formalin-latex (RFL) -based adhesive; And an elastic layer formed on the adhesive layer and including at least one rubber selected from the group consisting of natural rubber and synthetic rubber.

The tire inner liner laminate according to a specific embodiment of the present invention will be described in more detail below.

According to one embodiment of the invention, a polyamide-based resin; And a copolymer comprising a polyamide-based segment and a poly-ether-based segment; An adhesive layer formed on at least one side of the base film and including a resorcinol-formalin-latex (RFL) -based adhesive; And an elastic layer formed on the adhesive layer and including at least one rubber selected from natural rubber and synthetic rubber.

As a result of research conducted by the inventors of the present invention, it has been found that a tire inner liner laminate in which a resorcinol-formalin-latex (RFL) adhesive and an elastic layer containing a predetermined component are formed on the base film does not significantly increase the thickness of the adhesive layer, It can be firmly pressed onto the tire carcass layer in the vulcanizing step of the tire forming process and the high temperature heating condition without using the rubber composition.

In addition, when the tire inner liner laminate is wound and joined to the inside of the pneumatic tire, both ends of the tire inner liner laminate can be firmly coupled without using any adhesive or adhesive member due to the action of the elastic layer . By using the tire inner liner laminate of this embodiment as described above, it is possible to prevent the durability deterioration due to the unevenness of the detailed structure of the pneumatic tire, and to provide a tire having a high durability and endurance characteristic against repetitive deformation, The weight of the tire can be reduced while improving the fuel efficiency of the vehicle.

As the tire inner liner laminate includes the above-described elastic layer, the tire inner liner laminate can have excellent tackiness, thereby preventing the laminate from being separated from the carcass layer during the production of the green tire, The occurrence of defects can be prevented.

In addition, in the vulcanization process at high temperature and high pressure, the adhesive layer and the elastic layer form a crosslinked structure and exhibit a strong adhesive force. Accordingly, the tire innerliner laminate can be firmly bonded to the tire carcass layer, Both ends of the tire inner liner laminate can be firmly coupled without any adhesive or adhesive material.

On the other hand, the elastic layer may have a thickness of 5 탆 to 100 탆, or 5 탆 to 30 탆.

If the thickness of the elastic layer is too thin, it is difficult for the tire inner liner laminate to have an adhesive property to the tire carcass layer, so that the installation and the operation of the inner liner laminate are not easy and both ends of the tire inner liner laminate are rigid It can be difficult to bond. If the thickness of the elastic layer is too large, the weight of the tire inner liner laminate and the entire tire increases, and when the elastic inner layer is used, automobile fuel consumption may be lowered.

As described above, the elastic layer may include at least one rubber selected from the group consisting of natural rubber and synthetic rubber. More specifically, the elastic layer may include natural rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber, And a butylene rubber.

The elastic layer may further include additives such as carbon black, pharaoh, zinc oxide, stearic acid, an antioxidant, sulfur, a vulcanization accelerator, an activator, a pressure-sensitive adhesive, and an adhesive in addition to the rubber component.

Meanwhile, the elastic layer may be formed from a coating liquid containing the rubber component, and the elastic layer may further include an organic solvent to form a coating liquid. The organic solvent is not particularly limited as long as it can dissolve the rubber component. For example, organic solvents such as toluene, naphtha and tetrahydrofuran may be used.

The concentration of the solid content in the coating liquid or the elastic layer containing the rubber component and the organic solvent may be 5 to 50% by weight, or 10 to 30% by weight.

If the concentration of the solid content in the coating liquid or the elastic layer including the rubber component and the organic solvent is too low, the elastic layer may be difficult to have a sufficient thickness, so that the elastic layer may not have adhesiveness and adhesion, , The manufacturing characteristics of the tire may be deteriorated, and tire failure may occur during traveling.

When the concentration of the solid content in the coating liquid or the elastic layer containing the rubber component and the organic solvent is too high, the viscosity of the adhesive liquid is lowered due to the increase of the viscosity, and the dispersibility of the rubber compound liquid is lowered, A problem such as thickness unevenness may be caused.

There is no particular limitation on the method of applying the coating liquid containing the rubber component and the organic solvent on the adhesive layer, and a known coating method can be applied. For example, a coating solution containing the rubber component and an organic solvent may be applied on the adhesive layer by a comma coating, a gravure coating method or the like.

The application of the coating liquid containing the rubber component and the organic solvent can be carried out at a temperature of 60 to 100 캜. This temperature is a suitable temperature for volatilizing the solvent.

As described above, the base film may be a polyamide based resin; And a copolymer comprising a polyamide-based segment and a poly-ether-based segment.

The polyamide based resin may have a relative viscosity (96% solution of sulfuric acid) of 2.5 to 4.0, preferably 3.2 to 3.8. If the viscosity of the polyamide resin is less than 2.5, a sufficient elongation can not be secured due to a reduction in toughness, which may lead to breakage during tire production or automobile operation, and the airtightness of the base film for the inner liner It may be difficult to ensure physical properties such as moldability. When the viscosity of the polyamide resin exceeds 4.0, the modulus or viscosity of the substrate film to be produced may become unnecessarily high, and the tire inner liner may be difficult to have proper moldability or elasticity.

The relative viscosity of the polyamide resin refers to the relative viscosity measured using a 96% solution of sulfuric acid at room temperature. Specifically, after dissolving a sample of a certain polyamide resin (for example, 0.025 g of a test piece) in 96% sulfuric acid solution at different concentrations to prepare two or more measuring solutions (for example, a polyamide based resin sample The solution for measurement was prepared by dissolving in 96% sulfuric acid to have a concentration of 0.25 g / dL, 0.10 g / dL and 0.05 g / dL), 25, the relative viscosity (for example, The ratio of the average passage time of the measuring solution to the viscosity tube passing time of the 96% solution of sulfuric acid).

Examples of polyamide based resins usable in the base film include polyamide based resins such as copolymers of nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 610, nylon 612, nylon 6/66, Nylon 6/66/610 copolymers, nylon MXD6, nylon 6T, nylon 6 / 6T copolymers, nylon 66 / PP copolymers and nylon 66 / PPS copolymers; Or N-alkoxyalkylates thereof, such as methoxymethylated 6-nylon, methoxymethylated 6,610-nylon or methoxymethylated 612-nylon, and nylon 6, nylon 66, nylon 66, 46, nylon 11, nylon 12, nylon 610 or nylon 612 may be preferably used.

The base film may include a copolymer including the polyamide-based segment and the poly-ether-based segment together with the polyamide-based resin, and may have a relatively low modulus with excellent airtightness. Specifically, due to the inherent molecular chain characteristics of the polyamide resin contained in the base film, the base film may exhibit airtightness of about 10 to 20 times at the same thickness as the butyl rubber generally used in a tire, The copolymer is present in a state of being bonded or dispersed among the polyamide based resins to further lower the modulus of the base film and to prevent the rigidity of the base film from rising and to prevent crystallization at high temperatures can do.

The weight average molecular weight of the copolymer comprising the polyamide segment and the polyether segment may be from 30,000 to 500,000, or from 70,000 to 300,000, or from 90,000 to 200,000. When the weight average molecular weight of the copolymer is less than 30,000, the base film may not have sufficient mechanical properties to be used for the polymer film for the inner liner, and the tire inner liner laminate tends to have insufficient gas barrier . If the absolute weight average molecular weight of the copolymer exceeds 500,000, the modulus or degree of crystallization of the base film may excessively increase upon heating at a high temperature, so that it may be difficult to ensure the elasticity or elastic recovery rate to be possessed as the polymer film for the inner liner.

In the present specification, the weight average molecular weight refers to the weight average molecular weight in terms of polystyrene measured by the GPC method. In the process of measuring the weight average molecular weight in terms of polystyrene measured by the GPC method, a detector such as a known analyzer and a refractive index detector, and an analyzing column can be used. Conditions, solvents, and flow rates can be applied. Specific examples of the measurement conditions include a temperature of 30, a chloroform solvent (Chloroform), and a flow rate of 1 mL / min.

The content of the polyether segment in the base film may be 2 wt% to 40 wt%, 3 wt% to 35 wt%, or 4 wt% to 30 wt%.

If the content of the polyether segment is less than 2% by weight of the total weight of the base film, the modulus of the base film becomes high and the moldability of the tire may be deteriorated or the physical properties may deteriorate due to repeated deformation. If the content of the polyether segment exceeds 40% by weight of the entire film, the gas barrier required for the tire inner liner is poor and tire performance may be deteriorated. The reactivity to the adhesive may be lowered, and the inner liner may be difficult to easily adhere to the carcass layer, and the elasticity of the base film may increase, making it difficult to produce a uniform film.

The polyamide-based segment of the copolymer may comprise repeating units 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, an arylene group having 6 to 20 carbon atoms, or a linear or branched alkylene group having 7 to 20 carbon atoms.

(2)

R ₂ is a linear or branched alkylene group having 1 to 20 carbon atoms or an arylene group having 6 to 20 carbon atoms, R ₃ is a linear or branched alkylene group having 1 to 20 carbon atoms, an alkylene group having 6 to 20 carbon atoms Or a linear or branched alkylene group having 7 to 20 carbon atoms.

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

(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-.

In the base film, the polyamide based resin and the copolymer comprising the polyamide based segment and the poly-ether based segment may be used in a ratio of 9: 1 to 1: 9, or 2: 8 to 8: 2 By weight. If the content of the polyamide resin is too small, the density or airtightness of the base film may be lowered. If the content of the polyamide resin is too large, the modulus of the base film may be excessively high or the moldability of the tire may be deteriorated. In a high temperature environment occurring in a tire manufacturing process or an automobile running process, And a crack can be generated by repeated deformation.

On the other hand, the base film includes an olefin-based polymer compound together with the polyamide-based resin and a copolymer including a polyamide-based segment and a poly-ether-based segment, It is possible to prevent the phenomenon of crystallization due to the crystallization of the base film and to improve the endurance characteristics and durability even at a low temperature by lowering the modulus characteristic or increasing the elasticity while maintaining the other mechanical properties of the base film at the same level or more.

Specifically, the olefin-based polymer compound can improve the softness of the base film and improve the ability to absorb external impact, and can also significantly reduce the modulus of the base film, It is possible to prevent the phenomenon that the internal structure of the compound or the polymer contained in the polymer is changed to crystallize.

The base film may contain 3 wt% to 35 wt%, or 10 wt% to 30 wt% of the olefin-based polymer compound. If the content of the olefin-based polymer compound is too small, the degree of action and effect of the olefin-based polymer compound may be insignificant. If the content of the olefin-based polymer compound is too large, the physical properties and effects expressed by the polyamide-based resin and the copolymer can be reduced. By applying the tire inner liner laminate of one embodiment, A decrease in physical properties due to heat in the vulcanization process may occur.

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

The olefin-based copolymer may be an ethylene-propylene copolymer or an ethylene-acrylic ester-maleic anhydride terpolymer, an acrylic ester-maleic anhydride copolymer, maleic anhydride functionalized polyolefin, ethylene-butyl acrylate-glycidyl methacrylate (GMA), terpolymer of ethylene, butylacrylate (BA) and glycidylmethacrylate (GMA).

As described above, the olefin-based polymer compound may include an olefin-based polymer or copolymer grafted with a dicarboxylic acid or an acid anhydride thereof. The dicarboxylic acid may be selected from the group consisting of maleic acid, phthalic acid, itaconic acid, , Alkenyl succinic acid, cis-1,2,3,6 tetrahydrophthalic acid, 4-methyl-1,2,3,6 tetrahydrophthalic acid, or a mixture of two or more thereof, and the dicarboxylic acid May be a dicarboxylic acid dianhydride of the above-mentioned examples.

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

The grafting ratio of the dicarboxylic acid or its acid anhydride can be determined from the results obtained by acid-base titration of the olefinic polymer. For example, about 1 g of the olefin-based polymer compound is placed in 150 ml of xylene saturated with water and refluxed for about 2 hours. A small amount of a 1% by weight thymol blue-dimethylformamide solution is added, and a 0.05 N sodium hydroxide-ethyl alcohol solution To obtain a solution of a dark blue solution. The resulting solution was again in a 0.05N hydrochloric acid / isopropyl alcohol solution until the solution turned yellow to determine its acid value. From this, the dicarboxylic acid grafted to the olefinic polymer compound The amount of acid can be calculated.

The olefin-based polymer compound may have a density of 0.77 g / cm 3 to 0.95 g / cm 3, or 0.80 g / cm 3 to 0.93 g / cm 3.

The base film may have a thickness of 20 to 300 mu m, preferably 40 to 250 mu m, more preferably 40 to 200 mu m. Accordingly, the polymer film for an inner liner according to an embodiment of the present invention has a low thickness and a low air permeability, for example, an oxygen permeability of 200 cm 3 / (m 2 24 hr 揃 atm) or less have.

On the other hand, the base film may be an inflation film. The present inventors have found that an inflation film produced by inflation molding a raw material containing a polyamide based resin and a copolymer containing the specific segments as described above has a transverse direction (TD) of the film, unlike a conventional flat film, ), It is possible to maintain a stable physical property with respect to the transverse direction (TD) of the film even after the heat treatment at a high temperature, so that the physical property deviation between the machine direction (MD) and the transverse direction (TD) of the film can be further reduced Were confirmed through experiments.

Since the inflation film has uniform physical properties in the machine direction (MD) and the transverse direction (TD) of the inflation film even after the high temperature heat treatment, the stress applied to the film during the molding process and the vulcanization process of the tire can be uniformly dispersed And it is easy to disperse the stress applied from the outside due to the physical property balance characteristic of the inflation film in the machine direction (MD) and the transverse direction (TD) The durability can be further improved by delaying the occurrence of cracks due to stress concentration and accelerating the propagation of the cracks.

The inflation film may be prepared by mixing a polyamide resin, a copolymer containing the specific segments, and a raw material containing the olefinic polymer compound optionally in a molten state in the form of a tube continuously produced through an extruder die Forming a bubble in the bubble; blowing a predetermined air into the bubble to swell the film in the width direction of the film; Cutting the folded and folded sides of the bubble by a device part such as a nip roll to divide the folded state into two flat plate states; A step of winding the film in a roll state after edge-trimming an edge of both sides of the film in the form of a flat plate, and the like.

The inflation film exhibits uniform physical properties over all directions, has a relatively high tensile strength and impact strength, and has a low modulus. Specifically, after the inflation film is heat treated at 170 for 30 minutes, The ratio of the modulus in the machine direction to the modulus in the transverse direction of the inflation film may be 0.8 to 1.2.

That is, when the inflation film is thermally treated at 170 for 30 minutes and the elongation is 25%, the modulus of the inflation film in the machine direction (MD) and the transverse direction (TD) The ratio of the modulus in the machine direction to the modulus in the transverse direction of the inflation film may be 0.8 to 1.2.

Specifically, the respective moduli in the machine direction and the transverse direction, which were measured by heat treating the inflation film for 30 minutes at 170 and 25% for elongation, were measured at a temperature of 23 and a relative humidity of 50% for 24 hours After standing, one end of the inflation film layer was suspended in a 170 hot air oven and immediately left to stand for 30 minutes in a no-load and no-contact state (heat treatment), a specimen of 30 mm in length and a specimen of 30 mm in width Can be defined as a strength value measured at an elongation of 25% in a machine direction and a transverse direction, respectively, by applying a tensile speed of 300 mm / min using an universal tensile tester (Instron, Tensile test machine).

In addition, the ratio of the impact strength in the machine direction to the impact strength in the transverse direction of the inflation film after heat treatment of the inflation film for one hour at 170 may be 0.8 to 1.2.

Specifically, the impact strength of the inflation film in the machine direction and in the transverse direction measured after heat treatment at 170 for 1 hour was measured after the inflation film was left at a temperature of 23 and a relative humidity of 50% for 24 hours, 170 After hanging one end of the inflation film layer in a hot air oven and placing (heat-treating) it in a no-load and no-contact state for 1 hour, under the environment of a temperature of 23 and a relative humidity of 50% Heat shock strength in the machine direction and in the transverse direction of the heat-treated inflation film measured using a pumped impact tester (Zwick / Roell, Model HIT 5.5P).

The inflation film of this embodiment satisfies the ratio of the modulus in the machine direction to the modulus in the transverse direction of the inflation film described above and the ratio of the impact strength in the machine direction to the impact strength in the transverse direction of the inflation film , It is possible to uniformly disperse the stress applied to the film during the molding process of the tire and the vulcanizing process so as to alleviate the residual stress of the inflation film and thereby to improve the moldability, Heat generation and durability can be minimized.

A specific method of producing the inflation film is as follows. For example, polyamide based resins; And a copolymer comprising a polyamide-based segment and a poly-ether-based segment, is inflated to an expansion ratio (BUR) of 1.5 to 3, whereby the inflation film described above can be provided have.

As described above, the inflation film comprises the polyamide-based resin; A copolymer comprising a polyamide-based segment and a poly-ether-based segment; And optionally an olefinic polymer compound, to an expansion ratio (BUR) of from 1.5 to 3, or from 1.8 to 2.7, or from 2.0 to 2.5.

The BUR (blow-up ratio) refers to a ratio of the degree to which the molten resin composition is extruded through the die to be stretched in the transverse direction after the bubble is formed. Specifically, the ratio is defined as a ratio of the bubble diameter to the die diameter .

For example, when the expansion ratio is excessively increased, for example, when the expansion ratio in the manufacturing process of the inflation film is more than 3, the tensile strength in the machine direction (MD) decreases but the molecular orientation in the transverse direction (TD) , The MD / TD physical property balance of the inflation film becomes poor, and the stability of the bubble is lowered in the process of manufacturing the inflation film, so that the processability may be lowered. If the expansion ratio is less than 1.5, it is difficult to form a stable bubble, so that the inflation film finally produced may have uneven thickness and poor physical properties and may be difficult to manufacture as a film.

The bubble diameter and the die diameter are not limited to a large extent in the step of expanding the molten resin composition to an expansion ratio (BUR) of 1.5 to 3, and it is possible to appropriately adjust the bubble diameter and die diameter in consideration of the size and physical properties of the inflation film to be finally produced, In the step of expanding the molten resin composition to an expansion ratio (BUR) of 1.5 to 3, the bubble diameter may be 450 to 2000 mm and the die diameter may be 300 to 800 mm.

In the step of expanding the molten resin composition to an expansion ratio (BUR) of 1.5 to 3, if the die diameter is too small, the die shear pressure becomes excessively high in the melt extrusion process and the shear stress becomes high so that the extruded film becomes a uniform bubble And thus the productivity may be deteriorated.

Further, in the step of expanding the molten resin composition at an expansion ratio (BUR) of 1.5 to 3, if the diameter of the die is too large, uniform expansion due to air is difficult in the melt extruded film, And wrinkles are so severe that it is difficult to obtain uniform physical properties, and there may be a problem that the processability is deteriorated.

On the other hand, the molten resin composition can be expanded to a draw ratio (DDR) of 1 to 20. The Draw Down Ratio (DDR) represents the degree to which the bubble is stretched in the longitudinal direction, and may be specifically defined as "die gap / (film thickness * expansion ratio)".

And, in the step of expanding the molten resin composition to a draw ratio (DDR) of 1 to 20, the die gap may be 0.5 to 3.5 mm and the film thickness may be 20 to 300 탆.

The temperature inside the bubble of the molten resin composition formed in the step of expanding the molten resin composition may be 10 to 60. [ If the temperature inside the bubble of the molten resin composition is too low, blocking between the films due to the occurrence of condensation may occur, or wrinkles may be introduced at the stage where the bubble is folded, In the step of dividing the both sides into two flat plate states by cutting, the processability is poor and the physical properties may be uneven,

If the temperature inside the bubble of the molten resin composition is too high, the morphology stability of the bubble may be lowered, wrinkles may be introduced or crystallization may occur, and the uniformity of the bubble may be deteriorated, And the durability may be deteriorated.

Wherein the molten resin composition is a polyamide based resin; A copolymer comprising a polyamide-based segment and a poly-ether-based segment; And melt-extruding a raw material containing an olefin-based polymer compound.

For example, the apparatus and method that can be used in the step of melting and extruding such a raw material are not limited to a great extent. For example, the method of producing the inflation film may be a polyamide based resin; A copolymer comprising a polyamide-based segment and a poly-ether-based segment; And an olefin-based polymer compound at 200 to 300 to form the molten resin composition. The melting temperature should be higher than the melting point of the polyamide compound. However, if the melting temperature is too high, carbonization or decomposition may occur to deteriorate the physical properties of the film, and bonding between the polyether resins may occur, . ≪ / RTI >

As described above, the inflation film is obtained by mixing the polyamide resin, the copolymer containing the specific segments, and the olefin polymer compound together in a molten state in a tube-shaped bubble continuously produced through an extruder die Blowing a predetermined air into the bubble to expand the inflation film in the width direction of the inflation film; Cutting the folded and folded sides of the bubble by a device part such as a nip roll to divide the folded state into two flat plate states; A step of winding the film in a roll state after edge-trimming an edge of both sides of the film in the form of a flat plate, and the like.

Specifically, the method of manufacturing the inflation film may further include: after the molten resin composition is folded by the nip roll, stretching the film continuously in the machine direction (MD) of the film.

Further, in the method of manufacturing the inflation film, inner-bubble-cooling (IBC) may be applied to control the temperature inside the bubble.

In addition, in the method for producing an inflation film, methods and apparatuses commonly used in the inflation process of the polymer film, except for the above-mentioned contents, can be used without limitation.

On the other hand, the manufacturing method of the inflation film may further include forming an adhesive layer formed on at least one surface of the inflation film formed from the molten resin composition and including a resorcinol-formalin-latex (RFL) .

On the other hand, the adhesive layer containing the resorcinol-formalin-latex (RFL) adhesive has excellent adhesion and adhesive holding performance to the base film and the tire carcass layer, To prevent fracture of the interface between the inner liner film and the carcass layer caused by heat or repetitive deformation, so that the polymer film for inner liner has sufficient fatigue resistance.

As described above, the adhesive layer containing the resorcinol-formalin-latex (RFL) -based adhesive may be formed on at least one surface, that is, one surface or both surfaces of the base film, and the adhesive layer may be formed on the opposite surface The elastic layer may be formed.

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

The condensate of resorcinol and formaldehyde may be obtained by mixing resorcinol and formaldehyde in a molar ratio of 1: 0.3 to 1: 3.0, preferably 1: 0.5 to 1: 2.5, followed by condensation. In addition, the condensate of resorcinol and formaldehyde may be contained in an amount of 2% by weight or more based on the total amount of the adhesive layer in terms of chemical reaction for excellent adhesion, and may be contained in an amount of 32% by weight or less have.

The latex may be one or a mixture of two or more selected from natural rubber latex, styrene / butadiene rubber latex, acrylonitrile / butadiene rubber latex, chloroprene rubber latex and styrene / butadiene / vinylpyridine rubber latex. The latex may be contained in an amount of not less than 68% by weight based on the total amount of the adhesive layer for the flexibility of the material and an effective crosslinking reaction with the rubber, and not more than 98% by weight for the chemical reaction with the base film and the rigidity of the adhesive layer.

The adhesive layer may have a thickness of from 0.1 to 20 占 퐉, preferably from 0.1 to 10 占 퐉, more preferably from 0.2 to 7 占 퐉, even more preferably from 0.3 to 5 占 퐉, As shown in FIG.

In the coating process used in the process of forming the adhesive or the elastic layer, a commonly used coating or coating method or apparatus may be used without any limitations. However, knife coating, bar coating, A gravure coating method, a spraying method, or a dipping method may 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.

According to the present invention, it is possible to achieve uniform durability and endurance characteristics against repeated deformation occurring at the time of running a tire while exhibiting uniform and excellent physical properties in all directions, having a relatively high tensile strength and impact strength, A tire inner liner laminate may be provided. Further, the tire inner liner laminate has excellent tackiness to prevent the occurrence of defects in the molding and vulcanizing process, and the thickness and the total weight of the tire can be reduced.

Fig. 1 schematically shows the structure of a tire.

The invention will be described 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.

[Preparation Example: Preparation of coating composition for forming elastic layer]

An elastomer was prepared from the rubber composition as shown in the following Table 1, and a mixed solvent in which toluene and tetrahydrofuran were mixed at a weight ratio of 80:20 was prepared. Next, an elastomer was dispersed in a mixed solvent at a concentration of 15% to prepare a coating composition for forming an elastic layer.

Elastic layer  Elastomer composition for forming ingredient Content (parts by weight) caoutchouc 60.0 Butadiene rubber 40.0 Carbon black 50.0 Zinc oxide 5.0 Stearic acid 2.0 Pharaoh, P # 2 12.0 Antioxidants, Rubber antioxidants 1.5 brimstone 1.5 Vulcanization accelerator, ZnBX 1.5

[Example: Production of tire inner liner laminate]

≪ Example 1 >

(1) Manufacture of inflation film

(nylon 6) having a relative viscosity of 3.2% (sulfuric acid 96% solution) prepared from epsilon -caprolactam and a copolymer resin having a weight average molecular weight of about 92,000 (copolymer having a poly (tetramethylene oxide) Propylene copolymer grafted with maleic anhydride (0.9 wt%) (density: 0.890 g / cm < 3 >) was synthesized by using a mixture of 35 wt% of an ether segment and 65 wt% of a polyamide segment derived from epsilon -caprolactam) 1 part by weight of the oxazoline compound and 100 parts by weight of the mixture were mixed at a weight ratio of 20:62:18, and the content of copper (Cu) in the mixture of copper iodide and potassium iodide was 7 wt% By weight was added to prepare an inflation film-forming mixture.

Then, the mixture was extruded at 240 to maintain a uniform molten resin flow through a circular die (Die Gap - 2.0 mm, Die Diameter: 500 mm) The inner temperature of the bubble was adjusted to 17 using an inner bubble cooler (IBC), and the blow-up ratio (BUR) of the bubble was adjusted to 2.1 by controlling the air volume and the discharge volume of the blower , And a bubble having a diameter of 1,050 mm was formed with a drawdown ratio (DDR) of 11.9. The bubbles are made flat by using a nip roll through a flat support, and the both sides are cut into two flat films by cutting with a blade, and then the two sides of each film are cut And wound up on a winder to obtain a flat-type inflation film having a thickness of 80 mu m.

(2) Application of adhesive

Resorcinol and formaldehyde were mixed at a molar ratio of 1: 2, followed by condensation reaction to obtain a condensate of resorcinol and formaldehyde. A resorcinol-formalin-latex (RFL) -based adhesive having a concentration of 25% was obtained by mixing 15% by weight of the condensate of resorcinol and formaldehyde and 85% by weight of styrene / butadiene-1,3 / vinylpyridine latex.

The resorcinol-formalin-latex (RFL) -based adhesive was coated on both sides of the inflation film using a gravure coater and dried and reacted at 150 for 1 minute to form adhesive layers each having a thickness of 3 μm on both sides.

(3) Formation of elastic layer

Preparation Example of the Production Example of the Production Example: A coating composition for forming an elastic layer was applied on the adhesive layer formed using a comma coater, and the solvent was volatilized at a temperature of 80 to form a rubber compound layer. As a result, a tire inner liner laminate having a rubber compound layer thickness of 20 mu m was produced.

(4) Tire manufacturing

A tire of the rubber 205 / 55R16 standard was manufactured and evaluated by applying the manufactured inner liner film. At this time, 1300De '/ 2ply HMLS tire cord was used as the cord included in the body fly, steel cord was used as the belt, and N66 840De' / 2ply product was used as the cap fly.

Laminating a body flour rubber on the inner liner film; A belt portion; Cap fly portion; And a rubber layer for forming a tread portion, a shoulder portion, and a side wall portion were sequentially formed to produce a green tire.

The green tire thus prepared was placed in a mold and vulcanized for 160 minutes for 20 minutes to produce a tire.

≪ Example 2 >

(1) Production of the Inflation Film

(Synthesized by using ε-caprolactam and hexamethylene diamine and adipic acid in a weight ratio of 94: 6) and a polyamide-based copolymer resin having a relative viscosity of 96% (sulfuric acid solution) A copolymer resin having an average molecular weight of about 123,000 (synthesized using 20% by weight of a polyether segment having an amine terminal group as a main chain of polytetramethylene oxide and 80% by weight of a polyamide segment derived from? -Caprolactam) and Propylene copolymer grafted with maleic anhydride (0.7 wt%) (density: 0.920 g / cm3) was mixed at a weight ratio of 30: 65: 5, and 0.4 part by weight of an oxazoline compound relative to 100 parts by weight of the mixture, , And 0.2 part by weight of copper iodide (potassium iodide) and copper (Cu) in a mixture of 7 wt%] were added to prepare an inflation film-forming mixture.

Then, the mixture was extruded at 230 from a circular die (Die Gap - 3.0 mm, Die Diameter 400 mm) while maintaining a uniform molten resin flow, and air-ring and inner The inner temperature of the bubble was adjusted to 25 by using an inner bubble cooler (IBC), and the blow-up ratio (BUR) of the bubble was adjusted to 2.88 by controlling the air volume and the discharge volume of the blower , And a bubble having a diameter of 1,150 mm was formed by setting the Draw Down Ratio (DDR) to 8.0. The bubbles are made flat by using a nip roll through a flat support, and the both sides are cut into two flat films by cutting with a blade, and then the two sides of each film are cut And wound on a winder to obtain the inflation film in the form of a flat having a thickness of 130 mu m.

(2) Application of adhesive

An adhesive layer was formed in the same manner as in Example 1 except that an adhesive layer having a thickness of 2 mu m was formed on both surfaces of the inflation film.

3) Formation of elastic layer

An elastic layer having a thickness of 50 mu m was formed in the same manner as in Example 1, and tires were produced in the same manner as in Example 1. [

 [Comparative Example 1: Production of inner liner film using butyl rubber and natural rubber]

(1) Production of base film

30 parts by weight of carbon black, 3 parts by weight of paraffin oil, 2 parts by weight of zinc oxide, 1 part by weight of stearic acid, 2 parts by weight of an antioxidant were added to 100 parts by weight of raw rubber containing 60% by weight of butyl rubber and 40% , 1 part by weight of sulfur and 1 part by weight of a vulcanization accelerator were put in a mixer to prepare a semi-finished innerliner having a constant thickness (1.00 mm). Tire production was carried out in the same manner as in Example 1.

[Comparative Example 2: Production of tire inner liner]

(1) Production of base film

(nylon 6) having a relative viscosity (3.8% solution of sulfuric acid) of 3.8 produced from? -caprolactam and a copolymer resin having a weight average molecular weight of about 137,000 (a poly (methylene oxide) 16% by weight of an ether-based segment and 84% by weight of a polyamide-based segment derived from? -Caprolactam) was mixed at a weight ratio of 90:10 to prepare a mixture for producing a base film.

Then, the mixture was extruded at 255 at a die-gap (Die Gap - 1.2 mm) while maintaining a uniform molten resin flow, and the molten resin was extruded using an air knife And cooled and solidified on a film of uniform thickness. Then, a substrate film having a thickness of 100 mu m was obtained without passing through a stretching and heat treatment section at a speed of 10 m / min.

(2) Application of adhesive

Resinolinol-formalin-latex (RFL) -based adhesive was coated on both sides of the base film using a gravure coater and dried and reacted at 150 for 1 minute in the same manner as in Example 1 to give adhesive layers each having a thickness of 3 μm . Tires were produced in the same manner as in Example 1 except that the elastic layer was formed.

<Experimental Example>

Experimental Example 1: Measurement of Film and Coating Layer Thickness

The thickness of the inflation film and coating layer prepared in Examples and Comparative Examples was measured using Mitutoyo's Digimatic Thickness Gauge (Model No. 547-401).

Experimental Example 2: Tacky Test

The adhesion between the tire innerliner laminate produced in each of the above Examples and Comparative Examples and the unvulcanized rubber used in the tire carcass layer was evaluated.

The unvulcanized rubber (thickness 1.0 T) used for the carcass layer and the tire innerliner laminate were laminated and pressed with a metal cylindrical weight having a load of 5 kgf to prepare a rubber-film composite. After the rubber-film composites thus prepared were cut at intervals of 1 inch, scotch tape was applied to both sides of the exposed surface of the rubber-film composite to prevent stretching. Then, an Instron Clamp (Grip, CAT. No. 2712- 041) was used to measure the peel strength at a crosshead speed of 125 mm / min. At this time, the average value of the load generated at the time of peeling was calculated by the adhesive force.

Experimental Example 3: Adhesion (PEEL) test

The adhesive peel strength of the tire innerliner laminate produced in each of the above Examples and Comparative Examples was measured according to the method of American Society for Testing and Materials Standards ASTM D 4393 on the tire carcass layer.

Specifically, a 1.6 mm rubber sheet, a cord paper, the tire innerliner film, a 1.6 mm rubber sheet, a cord paper, and a 1.6 mm rubber sheet were laminated in this order, Sulfur. The vulcanized sample was then cut and cut to a width of 1 inch. Then, the cut sample was peeled at a speed of 25 to 125 mm / min using an all-purpose material tester (Instron) to measure the adhesion of the tire innerliner laminate to the carcass layer. At this time, the average value of the load generated at the time of peeling was calculated by the adhesive force.

Experimental Example 4: Failure rate of tire manufacturing

The incidence of defects during the manufacturing process of the tire inner liner laminate manufactured in each of the above Examples and Comparative Examples was investigated (due to the characteristic of the manufacturing process of the tire, the reinforcement material should have a sticking performance of a certain level or higher so that the rubber reinforcement If the rubber reinforcement does not have a certain level of adhesion performance because it can be attached to the rubber to lead to the manufacturing process of the tire, a failure due to flowing down during the tire manufacturing process may occur).

Twenty tires were manufactured for each of the tires using the tire inner liner laminate manufactured in each of the examples and the comparative examples, and the defective tire production rate was determined according to the following equation (1).

Tire Manufacturing Failure Rate (%) = [(Good tire number) / (20, Tire evaluation number)] x 100

Experimental Example 5: Tire weight index

Twenty tires were prepared by the method described in Example 1 using the tire inner liner laminate produced in each of the above Examples and Comparative Examples. The weight of the thus produced tire was measured and averaged.

Experimental Example 6: Measurement of tire air pressure maintenance performance

Using the tire inner liner laminate produced in each of the above Examples and Comparative Examples, the tire produced by the method described in Example 1 was vulcanized under a pressure of 101.3 kPa at a temperature of 21 using ASTM F1112-06 method And the air pressure retention ratio for 90 days was measured and compared.

Experimental Example 7: Tire durability measurement experiment

The tires manufactured by the method described in Example 1 using the tire inner liner laminate manufactured in each of the above Examples and Comparative Examples were subjected to an evaluation of the durability of tires by increasing the load using the FMVSS139 tire durability measurement method . This durability measurement was carried out by two methods of an endurance test for increasing the load by the step load method and a high speed test for increasing the speed. The results of the comparative example were compared with those of the comparative example.

Experimental Example 8: Tire running test

The tires manufactured by the method described in Example 1 using the tire inner liner laminate produced in each of the above-described Examples and Comparative Examples were subjected to a test run at a speed of 0 to 140 km / h at a low / (Ride, Handling, Steering) were evaluated by evaluating the level of vibration introduced by nonuniformity. More specifically, the level of vibration introduced from the road surface to the tire, the vehicle body, and the steering wheel during the vehicle traveling was evaluated by the SAE 10-grade (sensitivity evaluation). The tire driving noise evaluation experiment was carried out with a pressure of 33 psi under a load of 80 km / h in the actual vehicle condition (large riding standard), and the measurement was performed in dB according to the frequency. In order to exclude the effect of the vehicle, we conducted the evaluation of the proximity sound of the tire. The results of Comparative Example 1 were evaluated as 100, and the results of Examples and Comparative Examples were compared and evaluated.

Example 1 Example 2 Comparative Example 1 Elastic layer thickness (um) 20 45 - Adhesion (gf / inch) 1591 2333 740 Adhesion (kgf / inch) 53.2 57.2 25.5 Tire forming defects 0 0 0 Tire Weight (kg) 7.34 7.45 8.15 Air pressure maintenance performance (%) 98. 98.2 96.0 tire
durability
(%) Endurance
Test 115
(2:25) 108
(2:16) 107
(2:15) High Speed
Test 119
(8:12) 114
(7:49) 100
(6:52) tire
Driving
(%) Ride 6.6 (97%) 6.7 (99%) 6.8 (100%) Handling 6.9 (101%) 6.7 (99%) 6.8 (100%) Steering 6.8 (100%) 7.1 (104%) 6.8 (100%)

As shown in Table 2, the tire inner liner laminate produced in the example has a relatively high tackiness and adhesion property as including the elastic layer, and thus the laminate is separated from the carcass layer during the production of green tire It is possible to prevent the occurrence of defects in processes such as tire formation and vulcanization.

Also, it was confirmed that the tire manufactured in the Example can achieve a weight reduction of about 0.7 to 0.8 kgf / ply while securing high airtightness as compared with Comparative Example 1, and it was confirmed that the automobile fuel economy can be improved.

In addition, the tire manufactured in the Example exhibited high durability and endothelium resistance against repeated deformation, and exhibited a driving performance and noise preventing effect equal to or higher than that of Comparative Example 1 (current tire) It was confirmed that it was.

Claims (13)

Polyamide based resin; And a copolymer comprising a polyamide-based segment and a poly-ether-based segment;
An adhesive layer formed on at least one side of the base film and including a resorcinol-formalin-latex (RFL) -based adhesive; And
And an elastic layer formed on the adhesive layer and including at least one rubber selected from the group consisting of natural rubber and synthetic rubber.
The method according to claim 1,
Wherein the elastic layer has a thickness of 5 占 퐉 to 100 占 퐉.
The method according to claim 1,
Wherein the elastic layer comprises at least one selected from natural rubber, styrene butadiene rubber, butadiene rubber, chloroprene rubber and isobutylene rubber.
The method according to claim 1,
Wherein the elastic layer further comprises an organic solvent,
Wherein a concentration of the solid content in the elastic layer is 5 to 50 wt%.
The tire inner liner laminate according to claim 1, wherein the polyamide based resin has a relative viscosity (96% sulfuric acid solution) of 2.5 to 4.0.
The method according to claim 1,
Wherein the copolymer comprising the polyamide segment and the polyether segment has a weight average molecular weight of 30,000 to 500,000.
The tire innerliner laminate according to claim 1, wherein the content of the polyether segment in the base film is 2 wt% to 40 wt%.
The olefin polymer composition according to claim 1, wherein the base film comprises at least one olefinic polymer selected from the group consisting of an olefinic polymer, an olefinic copolymer, and an olefinic polymer or copolymer obtained by grafting a dicarboxylic acid or an acid anhydride thereof Further comprising a tire inner liner laminate.
The tire according to claim 8, wherein the content of the grafted dicarboxylic acid or an acid anhydride thereof in the olefin-based polymer or copolymer grafted with the dicarboxylic acid or an acid anhydride thereof is 0.3 wt% to 3 wt% Inner liner laminate.
The tire innerliner laminate according to claim 8, wherein the base film comprises 3% by weight to 35% by weight of the olefin-based polymer compound.
The tire inner liner laminate according to claim 1, wherein the base film is an inflation film.
12. The tire according to claim 11, wherein the inflation film has a modulus in the machine direction of 0.8 to 1.2 with respect to the modulus in the transverse direction of the inflation film at an elongation of 25% after heat treatment at 170 for 30 minutes, Laminates.
12. The method of claim 11,
Wherein the ratio of the impact strength in the machine direction to the impact strength in the transverse direction of the inflation film is 0.8 to 1.2 after heat treatment of the inflation film at 170 conditions for 1 hour.

Images