KR20160002138A - Polymer film - Google Patents

Abstract

The present invention relates to a polymer film comprising a copolymer which includes: a polyamide-based repeating unit; a polyether-based repeating unit; an arylene acyl repeating unit containing an arylene group with 6 to 20 carbon atoms and at least two acyl functional groups.

Description

POLYMER FILM

More particularly, the present invention relates to a polymer film which realizes excellent airtightness even with a thin thickness, and can be used as an inner liner film to lighten a tire and improve automobile fuel economy. In addition, it has excellent durability, And a polymer film having physical properties such as fatigue resistance.

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 (or pneumatic tires), which are filled with high-pressure air of about 30 to 40 psi, are usually used without using a tube. In the course of vehicle operation, The inner liner having high airtightness is disposed in 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.

In addition, the rubber components have relatively low heat resistance, and air pockets are formed between the inner rubber of the carcass layer and the inner liner during the vulcanization process of the tire or the running of the vehicle in which repeated deformation occurs at high temperature, There is a problem that the shape and physical properties are changed. In order to bond the rubber components to the curl layer of the tire, a vulcanizing agent or a vulcanization process has to be applied.

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, .

Recently, as oil prices have increased, interest in eco tires (eco-friendly tires) that can improve automobile fuel efficiency has increased, and attempts have been made to reduce the weight of tires or to reduce the ground area through changes in tire compounds or changes in tread design. I have been. However, according to the previously known method, there is a certain limit to improve the stability of the running stability and the shape stability of the tire, and to reduce the weight of the tire and to improve the automobile fuel economy.

The present invention realizes excellent airtightness even with a thin thickness so that a polymer film having physical properties such as high durability, high heat resistance, and high fatigue resistance can be obtained by reducing the weight of a tire when used as an inner liner film, .

In the present specification, polyamide based repeating units; Polyether-based repeating units; And an arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least two acyl functional groups.

The polymer film according to a specific embodiment of the present invention will be described in more detail below.

According to one embodiment of the invention, polyamide based repeating units; Polyether-based repeating units; And an arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least two or more acyl functional groups.

The present inventors proceeded with research on the material of the inner liner film to solve the limitations of previously used rubber components such as butyl rubber or halobutyl rubber and found that the rubber composition of the present invention has high elasticity and low A novel copolymer having excellent mechanical properties together with modulus characteristics was synthesized and the invention was completed.

Particularly, the copolymer has chemical structural properties including an arylene acyl repeating unit including an arylene group having 6 to 20 carbon atoms and at least two acyl functional groups, And excellent moldability and high heat resistance and heat resistance can be secured. Accordingly, the physical properties may not be significantly changed even during tire molding process or automobile running process in which repeated deformation occurs at high temperature, and the ratio of crystallization at high temperature is relatively high It is possible to prevent crystallization of the film itself due to a rise in temperature and breakage of the film accordingly.

In the present specification, the arylene group means a divalent functional group derived from arene.

The arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least 2 or more acyl functional groups is preferably a dicarboxylic acid or poly-carboxylic acid containing an arylene group having 6 to 20 carbon atoms And may be derived from a raw material such as terephthalic acid or isophthalic acid used in the production of the polymer film, for example.

Specific examples of the arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least 2 or more acyl functional groups include repeating units represented by the following formula (4).

[Chemical Formula 4]

In Formula 4, Ar is an arylene group having 6 to 20 carbon atoms.

The copolymer may contain 0.1 to 20% by weight, or 1 to 10% by weight, of the arylene acyl repeating unit.

If the content of the arylene acyl repeating unit in the copolymer is too small, heat resistance or thermal shock resistance may not be sufficiently secured, and the physical properties of the polymer film may deteriorate when exposed to high temperature conditions of 100 ° C or higher. If the content of the arylene acyl repeating unit in the copolymer is too high, the content of the polyamide repeating repeating unit or the polyether repeating unit is reduced, and the airtightness and durability of the polymer film may be deteriorated, The modulus may increase or the elasticity or moldability may deteriorate.

The polyamide repeating repeating unit may include a repeating unit represented by 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 and R ₃ 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.

The content of the polyamide-based repeating units in the copolymer may be determined in consideration of the physical properties and end use of the copolymer or the polymer film to be finally produced. Specifically, the copolymer may include a polyamide-based repeating unit in the content of the remaining amount excluding the polyether-based repeating unit and the component that can be optionally contained with the arylene acyl repeating unit.

The polyether-based repeating unit 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-.

On the other hand, the content of the polyether repeating unit in the polymer film may be 2 wt% to 40 wt%, or 3 wt% to 35 wt%, or 4 wt% to 30 wt%, or 5 wt% to 25 wt% . If the content of the polyether-based repeating unit in the polymer film is too low, the modulus of the polymer film becomes high, so that the moldability of the inner liner or the tire may deteriorate or the physical properties of the polymer film may deteriorate due to repeated deformation. If the content of the polyether repeating unit in the polymer film is too high, the gas barrier property required as a tire inner liner is poor, and the tire performance may be deteriorated. The reactivity to the adhesive may be lowered so that the inner liner may be difficult to easily adhere to the carcass layer, and the elasticity of the polymer film may increase, making it difficult to produce a uniform film.

The polyether-based repeating unit may be derived from a monomer, oligomer or polymer having a weight average molecular weight of 500 to 10,000, preferably 1,000 to 3,000. When the weight average molecular weight of the precursor of the polyether-based repeating unit is less than 500, it may not be possible to appropriately suppress the growth of large crystals or lower the modulus in the polymer film. When the weight average molecular weight of the precursor of the polyether-based repeating unit is more than 10,000, the airtightness and durability of the polymer film may be deteriorated.

On the other hand, the polymer film may have a relative crystallinity lower than 50%, which is defined as a ratio of the crystalline IR peak size and the crystalline IR peak size to the total amorphous IR peak size. That is, the polymer film has a high degree of crystallinity, and thus high elasticity and moldability can be secured.

The degree of crystallization may be less than 50% even when the polymer film is exposed to a high temperature condition of 100 ° C or more or 150 ° C or higher for a predetermined time, and the rate of change of crystallinity after exposure to the high temperature condition is 10% Or less than 5%.

Specifically, the polymer film may have a relative crystallinity of less than 50% before and after the heat treatment at 170 ° C for 1 hour and at 100 ° C for 24 hours, and the relative crystallinity before heat treatment at 170 ° C for 1 hour and 100 ° C for 24 hours The rate of change of relative crystallinity after the heat treatment may be less than 10% or less than 5%.

The polymer film may have a thickness of 30 to 300 占 퐉, preferably 40 to 250 占 퐉, more preferably 40 to 200 占 퐉. Accordingly, the polymer film of one embodiment of the invention may have a low air permeability, for example, less than 200 cc / (m 2 24 hr 揃 atm) while having a thin thickness as compared with previously known. Specifically, the oxygen permeability of the polymer film of this embodiment measured at a temperature of 23 캜 and a relative humidity of 55% RH for 24 hours through the ASTM D 1434 method is 200 cc / (m 2 24 hr 揃 atm) or less, or 20 (M 2 · 24 hr · atm), or from 30 to 120 cc / (m 2 · 24 hr · atm).

The copolymer may have a weight average molecular weight of 50,000 to 300,000, or 70,000 to 250,000. The weight average molecular weight of the copolymer is less than 50,000, and mechanical properties and heat resistance sufficient to use the polymer film as a tire inner liner film may not be ensured. If the weight average molecular weight of the copolymer is more than 300,000, the modulus or degree of crystallization of the polymer film may excessively increase upon heating at a high temperature, and it may be difficult to secure the elasticity or elastic recovery rate to be provided as the film for inner liner.

On the other hand, the polymer film may further include a polyamide resin having a relative viscosity (96% solution of sulfuric acid) of 3.0 to 4.0 or 3.2 to 3.5, optionally in combination with the above-mentioned copolymer.

If the viscosity of the polyamide resin is less than 3.0, a sufficient elongation can not be secured due to a decrease in toughness of the polymer film, so that breakage may occur during tire manufacturing or automobile operation, and the polymer film should have an inner liner film It may be difficult to ensure physical properties such as airtightness or moldability. When the viscosity of the polyamide resin exceeds 4.0, the modulus or viscosity of the polymer film to be produced may be unnecessarily high, and it may be difficult to have proper moldability or elasticity as a tire inner liner.

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 was dissolved in 96% sulfuric acid so as to have a concentration of 0.25 g / dL, 0.10 g / dL and 0.05 g / dL to prepare three measurement solutions), and the relative viscosity of the solution for measurement , 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 polymer 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 is preferably used.

In addition, the polyamide resin may be incorporated into the polymer film by preparing a polymer film using a monomer of the polyamide resin or a precursor of the polyamide resin, as well as a method of using the resin itself.

The polymer film may be blended with the polyamide resin having a relative viscosity of 3.0 to 4.0 (96% solution of sulfuric acid) and the copolymer in an appropriate ratio in consideration of specific physical properties and shape of the inner liner film to be finally produced , For example a polyamide based resin having a relative viscosity of 3.0 to 4.0 (96% solution of sulfuric acid): the weight ratio of the copolymer may be from 7: 3 to 3: 7.

When the polymer film includes a polyamide resin having a relative viscosity of 3.0 to 4.0 (a 96% solution of sulfuric acid) together with the above-mentioned copolymer, the content of the polyether repeating unit in the polymer film is 2 By weight, or 40% by weight, or 3% by weight to 35% by weight, or 4% by weight to 30% by weight, or 5% by weight to 25% by weight.

On the other hand, the polymer film may further contain 10 to 500 ppmw of a heat resistant agent.

If the content of the heat resistant agent is less than 10 ppmw, the effect of improving the heat resistance may be insufficient. If the content of the heat resistant agent exceeds 500 ppmw, the physical properties of the polymer film may be deteriorated, Thereby unnecessarily raising the price of the final product.

Specific examples of such heat resisting agents include aromatic amine compounds, hindered phenol compounds, phosphorus compounds, inorganic compounds, polyamide compounds, polyether compounds, or a mixture of two or more thereof.

Specific examples of the hindered phenol compound include N, N'-hexamethylenebis (3,5-ditertiary-4-hydroxy-hydrosinamide) or pentaerythritol tetrakis 3- (3,5- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate as a commercially available product, and Irganox 1010 as a commercially available product. Examples of possible hindered phenol compounds are not limited thereto.

Specific examples of the aromatic amine compound include 2,2,4-trimethyl-1,2-dihydroquinoline or a polymer thereof, phenyl? -Naphthylamine, phenyl-? -Naphthylamine, aldol-? -Naphthylamine N, N'-bis (1-ethyl-3-methylphenyl) -p-phenylenediamine, p-iso-propoxyldi Phenylamine, 6-ethoxy-2,2,4-trimethyl 1,2-dihydroquinoline, N-phenyl-N'-isopropyl-para-phenylenediamine, di-beta-naphthyl- (3, 3, 5-di-tert-butyl) -4- (4-methylphenyl) Hydroxyphenyl-propionamide) or a mixture of two or more thereof. However, examples of the aromatic amine compound usable as the heat resisting agent are not limited thereto.

Specific examples of the phosphorus compound include triphenyl phosphate (PPP), triaryl phosphate, aromatic phosphate ester, 2-ethylhexyldiphenyl phosphate, triethylene phosphate, tricresyl phosphate (TCP), cresylphenyl phosphate, chlorethyl phosphate , Tris-β-chloropropyl phosphate, tris-dichloropropyl phosphate, halogen-containing condensed phosphate esters, aromatic condensed phosphoric acid esters, polyphosphates, red phosphorus or a mixture of two or more thereof. Examples of the phosphorus compounds usable as the heat resisting agent But is not limited thereto.

Specific examples of the inorganic compound include iodinated compounds such as Mg (OH) ₂ , Al (OH) ₂ , Sb ₂ O ₃ , Sodium salt, Sb ₂ O ₅ , Zinc borate, Molybdenum compound, Zinc tartrate, CuI or KI And mixtures of two or more thereof.

Especially, the hindered phenolic compound as the heat resisting agent; And at least one compound selected from the group consisting of an aromatic amine compound, a phosphorus compound, an inorganic compound, a polyamide compound and a polyether compound can greatly improve the heat resistance of the polymer film, The change in the physical properties of the polymer film itself is not significant even when it is left for a long time or exposed.

Specifically, when one kind of compound selected from the group consisting of an aromatic amine compound, a phosphorus compound, an inorganic compound, a polyamide compound and a polyether compound is used together with the hindered phenol compound as a heat resisting agent, The heat resistance of the polymer film can be increased and the proportion of physical properties degraded by exposure to high temperature for a long time can be greatly reduced, while the amount of use is reduced as compared with the case of using a compound.

More preferably, the use of the hindered phenol compound, the phosphorus compound and the inorganic compound significantly reduces the content of the heat resistant agent (for example, 100 ppm to 500 ppmw in the polymer film) The long-term heat resistance can be greatly improved without substantially affecting other physical properties.

Further, even when a mixture of CuI and KI is used as the heat resisting agent, the heat resistance of the polymer film can be greatly improved, and even when exposed to a high temperature for a long time or exposed, the physical properties of the polymer film itself are not greatly changed.

When a mixture of CuI and KI is used as the heat resisting agent, it may be used in an amount of 50 ppmw to 300 ppw based on the polymer film. And, the content of copper (Cu) in the mixture of CuI and KI may be 5 to 10 wt%.

Even when a mixture of CuI and KI is used, the content of the heat resisting agent used is greatly reduced (for example, from 50 ppmw to 300 ppmw in the polymer film), and the long term heat resistance is greatly improved without affecting other physical properties of the polymer film .

On the other hand, according to the above-described specific composition and the use of the heat resistant agent, the polymer film does not change its physical properties even when exposed or exposed for a long time in a high temperature environment, It is possible to prevent crystallization or curing to a high level to prevent the moldability from being significantly deteriorated, and it is possible to prevent cracks or breakage from occurring in the inner liner even in a running process of a vehicle in which high temperature is generated due to repetitive deformation.

Meanwhile, the polymer film of one embodiment may further include an adhesive layer formed on at least one surface of the polymer film and including a resorcinol-formalin-latex (RFL) -based adhesive.

The adhesive layer containing the resorcinol-formalin-latex (RFL) adhesive enables the polymer film to have excellent adhesion and adhesive holding performance to the tire carcass layer. Accordingly, in the manufacturing process of the tire, It is possible to prevent breakage of the interface between the inner liner film and the carcass layer caused by heat generated or repetitive deformation, so that the polymer film of one embodiment can have sufficient fatigue resistance when applied as an inner liner film.

The main characteristic of the adhesive layer described above appears to be due to the inclusion of certain resorcinol-formalin-latex (RFL) based adhesives having a particular composition. Previously, as the adhesive for the inner liner of a tire, a rubber type tie gum or the like was used, and accordingly, an additional vulcanization process was required. On the contrary, the adhesive layer includes a resorcinol-formalin-latex (RFL) -based adhesive having a specific composition, and has high reactivity and adhesion to the polymer film, and is compressed The polymer film and the tire carcass layer can be firmly bonded.

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 0.1 to 20 占 퐉, preferably 0.1 to 10 占 퐉, more preferably 0.2 to 7 占 퐉, still more preferably 0.3 to 5 占 퐉, and one surface or both surfaces of the polymer film As shown in FIG.

If the thickness of the adhesive layer is too thin, the adhesive layer itself may become thinner when the tire is inflated, the crosslinking adhesive force between the carcass layer and the base film may be lowered, and the stress may concentrate on a part of the adhesive layer. In addition, if the adhesive layer is too thick, the interface separation in the adhesive layer may occur and the fatigue characteristics may be deteriorated.

The application of the adhesive may be carried out by any conventional coating or coating method or apparatus without limitation, but it may be applied by a knife coating method, a bar coating method, a gravure coating method, a spraying 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.

The method of synthesizing the copolymer is not particularly limited, and the polyamide-based repeating unit; Polyether-based repeating units; And a precursor or reactant capable of forming an arylene acyl repeating unit at a reaction temperature of 100 ° C or higher.

In addition, the production method of the polymer film is not limited, and a conventionally known production method of a polymer film can be used.

For example, a polymer film can be formed by supplying a raw material containing the above-mentioned copolymer or optionally a polyamide resin or the like to an extrusion die, and melting and extruding at 230 to 300 ° C. The temperature for melting the raw material may be 230 to 300 占 폚, preferably 240 to 280 占 폚. The melting temperature should be higher than the melting point of the polyamide-based compound. However, when the melting point is too high, carbonization or decomposition may occur to deteriorate the physical properties of the film, and bonding between the polyether- Which may be disadvantageous for producing a film.

The extrusion die can be used without limitation as long as it can be used for extrusion of the polymer resin. However, in order to make the thickness of the polymer film more uniform or to prevent orientation in the polymer film, a T- .

Meanwhile, the step of forming the polymer film may include extruding the melt-extruded raw material into a film having a thickness of 30 to 300 mu m. The thickness of the produced film may be controlled by controlling the extrusion conditions such as the extruder discharge amount or the gap of the extrusion die, or by changing the winding speed of the extrudate during the cooling process or the recovery process.

In order to more uniformly adjust the thickness of the polymer film layer in the range of 30 to 300 mu m, the die gap of the extrusion die may be adjusted to 0.3 to 1.5 mm. In the step of forming the polymer film, if the die gap is too small, the die shear pressure of the melt extrusion process becomes too high and the shear stress becomes high, so that it is difficult to form a uniform film of the extruded film, If the die gap is too large, the stretching of the melt-extruded film becomes too high to cause orientation, and the difference in physical properties between the longitudinal direction and the transverse direction of the produced polymer film can be large.

Further, in the above-mentioned method of producing a polymer film, the thickness of the polymer film produced by the above-mentioned step is continuously measured, and the result of the measurement is fed back so that the portion of the extrusion die corresponding to the position where the uneven thickness appears, -Die by adjusting the lip gap adjusting bolt, it is possible to obtain a film having a more uniform thickness by reducing the deviation of the polymer film. In addition, automated process steps can be configured by using an automated system, such as an Auto Die system, to control the thickness of the film-feedback-extrusion die.

According to the present invention, it is possible to realize excellent airtightness even with a thin thickness, thereby making it possible to lighten the tire when used as an inner liner film and to improve automobile fuel economy, and to provide a polymer having physical properties such as high durability, high heat resistance and high fatigue resistance A film may be provided.

The polymer film is used as a tire inner liner film to ensure high airtightness and excellent moldability as well as high heat resistance and heat resistance. Accordingly, the physical properties of the polymer film are changed during the tire forming process and the running process And the rate of crystallization at a high temperature is relatively small, so that crystallization of the film itself due to a rise in temperature and consequent breakage of the film can be prevented.

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.

[ Example  And Comparative Example : Production of polymer film]

Example  One

In a 5 L reactor, 1.6 kg of? -Caprolactam, 400 g of polyoxypropylenediamine (molecular weight: about 2,000), 32.2 g of isophthalic acid and 4 g of phenolic antioxidant were added, 80 g of water was added, and the mixture was stirred at 130 ° C for 2 hours at 60 rpm .

The temperature of the reactor was raised to 240 ° C and the pressure was maintained at 14 kg / cm 2 and the reaction was carried out at 60 rpm for 1 hour. The pressure of the reactor was gradually removed for 1 hour to make atmospheric pressure, and the pressure was reduced at a pressure of 0.3 kg / cm < 2 > for 210 minutes to complete the polymerization reaction.

After completion of the polymerization reaction, the polymer was discharged by pressurization of 2 kg / cm 2 to prepare a polymer chip (P-1). The chip was washed with water for 24 hours at 95 ° C to remove unreacted material , And vacuum dried at 100 DEG C for 20 hours. The dried chips were extruded at a temperature of 250 캜 by a melt extruder to prepare a 120 탆 polymer film.

Example  2

A 120 탆 polymer film was prepared in the same manner as in Example 1, except that 33.2 g of terephthalic acid was used instead of 32.2 g of the isophthalic acid.

Example 3

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

The resorcinol-formalin-latex (RFL) -based adhesive was coated on the polymer film obtained in Example 1 at a thickness of 1 μm using a gravure coater and dried and reacted at 150 ° C. for 1 minute to form an adhesive layer Respectively.

Example 4

 (One) Manufacture of polymer films

The polyamide based resin (nylon 6) having a relative viscosity (96% solution of sulfuric acid) 3.3 and the polymer chip (P-1) obtained in Example 1 were mixed at a weight ratio of 4: 6. At this time, the temperature of the raw material supplying part was adjusted to 50 to 100 캜, and the mixture was supplied to the extrusion die while preventing the feeding failure due to fusion of the mixture in the extruder screw.

Then, the supplied mixture was extruded at a temperature of 260 DEG C while maintaining a uniform molten resin flow through a T-die (die gap - 1.0 mm), and an air knife And the molten resin was cooled and solidified on a film having a uniform thickness. Then, an unoriented polymer film having a thickness of 100 mu m was obtained without passing through a stretching and heat treatment section at a speed of 15 m / min.

(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. 12% by weight of a condensate of resorcinol and formaldehyde and 88% by weight of styrene / butadiene-1,3 / vinylpyridine latex were mixed to obtain a resorcinol-formalin-latex (RFL) adhesive having a concentration of 20%.

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

Comparative Example 1

A 120 탆 polymer film was prepared in the same manner as in Example 1 except that 29.2 g of adipic acid was used instead of 32.2 g of the isophthalic acid.

Comparative Example 2

A 120 탆 polymer film was prepared in the same manner as in Comparative Example 1, except that 4 g of the phenolic antioxidant was not used.

Comparative Example 3

A 120 탆 polymer film was prepared in the same manner as in Comparative Example 1 except that 6 g of the phenolic antioxidant was used.

[ Experimental Example : Measurement of Physical Properties of Polymer Film]

Experimental Example 1 : Melting point and crystallization temperature

The melting point and the crystallization temperature of the polymer film obtained in Examples 1 to 2 and Comparative Examples 1 to 3 were confirmed using a differential scanning calorimeter (DSC).

Experimental Example 2 : Relative viscosity

Each of the polymer films obtained in Examples 1 to 2 and Comparative Examples 1 to 3 was dissolved in 95% sulfuric acid, and the relative viscosity was measured at 25 ° C. using a Ubbelohde viscometer according to ASTM D446 Respectively. The relative viscosity was measured using a Ubbelohde Viscometer according to ASTM D446.

Experimental Example 3 : Tensile strength and tensile Modulus of elasticity

The specimen (width 15 mm) of each of the polymer films obtained in Examples 1 to 2 and Comparative Examples 1 to 3 was measured for tensile strength and tensile elastic modulus by applying a speed of 50 mm / min to a gauge length of 50 mm according to ASTM 882 Were measured

Experimental Example 4 : Oxygen permeability

Each of the polymer films obtained in Examples 1 to 2 and Comparative Examples 1 to 3 was placed in an oxygen permeability meter (Mocon, Ox-Tran 2/20), and oxygen and carrier gas (98% of nitrogen + 2% of hydrogen) Was measured for 24 hours at a temperature of 23 캜 while maintaining the relative humidity at 55%.

The results of Experimental Examples 1 to 4 are shown in Table 1 below.

Melting point
(° C) Crystallization temperature
(° C) Relative viscosity
(dl / g) The tensile strength
(MPa) Tensile modulus
(MPa) Oxygen permeability
[cc /
(M < 2 > * 24hr * atm)] Before heat treatment After heat treatment Before heat treatment After heat treatment Example 1 213.07 59.40 1.46 38.84 40.17 16.46 36.57 320 Example 2 216.40 67.07 1.61 41.76 42.11 17.65 32.55 300 Comparative Example 1 218.40 63.73 1.45 47.74 35.64 15.76 41.86 780 Comparative Example 2 218.40 65.07 1.45 59.53 32.41 17.49 45.26 800 Comparative Example 3 218.40 63.77 1.47 69.93 58.94 16.52 39.87 800

As shown in Table 1, the films obtained in Examples 1 and 2 were found to have a relatively low melting point and crystallization temperature as compared with the polymer films obtained in Comparative Examples 1 to 3, and the tensile strength and initial tensile modulus Was relatively high. In addition, the films obtained in Examples 1 and 2 have lower oxygen permeability than the films of Comparative Examples 1 to 3, and it is believed that high airtightness can be secured when used as an inner liner.

Experimental Example 5 : Evaluation of heat resistance

In the films obtained in Examples 1 and 2, the polymer films obtained in Comparative Examples 1 to 3 were each heat-treated in a UL oven at 170 占 폚 for 1 hour and at 100 占 폚 for 24 hours. The IR spectrum and the impact resistance of the polymer film before and after the heat treatment were confirmed.

The impact strength was measured using an impact tester (Zwick / Roell HIT5.5P) according to ASTM D6110.

IR spectra of polymer films before and after heat treatment Amorphous peak intensity
(1166 cm ^-1 ) Crystalline peak intensity (1203 cm ^-1 ) Cry ' / Amor ' Relative crystallinity (%) Example 1 Before heat treatment 0.258 0.223 0.864 46.362 After heat treatment 0.256 0.235 0.918 47.862 Example 2 Before heat treatment 0.249 0.221 0.888 47.021 After heat treatment 0.262 0.235 0.897 47.284 Comparative Example 1 Before heat treatment 0.258 0.223 0.864 46.362 After heat treatment 0.256 0.303 1.184 54.204 Comparative Example 2 Before heat treatment 0.196 0.232 1.184 54.206 After heat treatment 0.197 0.287 1.457 59.298 Comparative Example 3 Before heat treatment 0.255 0.265 1.039 50.962 After heat treatment 0.244 0.329 1.348 57.417

As shown in Table 2, the polymer films of Examples 1 and 2 were found to have a relative crystallinity of less than 50% before and after the heat treatment, which is the intensity of the crystalline peak versus the intensity of the amorphous peak. On the other hand, it was confirmed that the polymer films of Comparative Examples 1 to 3 had a relative crystallinity of 50% or more after the heat treatment and a relatively increased degree of crystallinity, especially after the heat treatment.

Impact strength before and after heat treatment of polymer film Thermal shock resistance (KJ / g) Before heat treatment After heat treatment Retention rate (%) Example 1 4050 2182 53.88 Example 2 3980 2213 55.60 Comparative Example 1 3517 655 18.62 Comparative Example 2 3567 424 11.89 Comparative Example 3 4050 765 18.89

As shown in Table 3, it was confirmed that the polymer films of Examples 1 and 2 had a heat-resistant impact strength of at least 2000 KJ / g and a thermal shock resistance retention ratio of 50% or more even after the heat treatment. On the contrary, the polymer films of Comparative Examples 1 to 3 were found to have a thermal shock resistance lower than 1000 KJ / g and a thermal shock resistance retention of less than 20% after the heat treatment.

That is, the polymer films of Examples 1 and 2 have high heat resistance and heat resistance, and when used as an inner liner film, changes in physical properties may not be significant during a tire forming process or an automobile running process in which repeated deformation occurs at a high temperature, The rate of crystallization at a high temperature is relatively small, so that crystallization of the film itself due to a rise in temperature and consequent breakage of the film can be prevented.

Claims (17)

Polyamide repeating repeats; Polyether-based repeating units; And an arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least two acyl functional groups.
The method according to claim 1,
The polymer film is used as an inner liner of a tire.
The method according to claim 1,
Wherein a relative crystallinity, defined as a ratio of a crystalline IR peak size and a crystalline IR peak size to an amorphous IR peak size sum, is less than 50%.
The method according to claim 1,
Wherein the oxygen permeability measured by the ASTM D 1434 method at a temperature of 23 캜 and a relative humidity of 55% RH for 24 hours is not more than 200 cc / (㎡ 24 hr 揃 atm).
The method according to claim 1,
Wherein the polyamide repeating repeating unit comprises a repeating unit represented by the following formula (1) or (2):
[Chemical Formula 1]

Wherein 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 and R ₃ 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.
The method according to claim 1,
Wherein the polyether-based repeating unit comprises a repeating unit represented by the following formula (3):
(3)

In Formula 3, R ₅ is a straight or branched alkylene group having 1 to 10 carbon atoms, n is an integer of 1 to 100,
R ₆ and R ₇ may be the same or different and are each a direct bond, -O-, -NH-, -COO- or -CONH-.
The method according to claim 1,
Wherein the content of the polyether-based repeating unit in the polymer film is 2 wt% to 40 wt%.
The method according to claim 1,
Wherein the arylene acyl repeating unit comprises a repeating unit represented by the following formula (4):
[Chemical Formula 4]

In Formula 4, Ar is an arylene group having 6 to 20 carbon atoms.
The method according to claim 1,
Wherein the copolymer comprises 0.1 to 20% by weight of the arylene acyl repeating unit.
The method according to claim 1,
Wherein the copolymer has a weight average molecular weight of 50,000 to 300,000.
The method according to claim 1,
Wherein the polymer film further comprises a polyamide resin having a relative viscosity (96% solution of sulfuric acid) of 3.0 to 4.0.
12. The method of claim 11,
A polyamide resin having a relative viscosity (a 96% solution of sulfuric acid) of 3.0 to 4.0: a weight ratio of the copolymer of 7: 3 to 3: 7.
The method according to claim 1,
Wherein the polymer film has a thickness of 30 to 300 占 퐉.
The method according to claim 1,
Further comprising 10 to 500 ppmw of heat resistant article.
15. The method of claim 14,
The heat resisting agent is a hindered phenol-based compound; And at least one compound selected from the group consisting of aromatic amine compounds, phosphorus compounds, inorganic compounds, polyamide compounds and polyether compounds.
The method according to claim 1,
Further comprising an adhesive layer formed on at least one side of the polymer film, the adhesive layer comprising a resorcinol-formalin-latex (RFL) adhesive.
17. The method of claim 16,
Wherein the adhesive layer has a thickness of 0.1 占 퐉 to 20 占 퐉.

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