KR20160080789A - Polymer film - Google Patents

Abstract

The present invention relates to a polymer film comprising a copolymer. The copolymer includes: a polyamide-based repeating unit; a polyether-based repeating unit; an arylene acyl repeating unit having an arylene group with carbon number of 6 to 20 and at least two acyl functional groups; and an alkylene acyl repeating unit having an alkylene group with carbon number of 1 to 10 and at least two acyl functional groups. Provided in the present invention is the polymer film, which has excellent moldability and material properties such as high durability, heat resistance, and the like.

Description

POLYMER FILM

The present invention relates to a polymer film. More particularly, the present invention relates to a polymer film having excellent properties such as high durability, heat resistance and low gas permeability, which can realize excellent airtightness even with a thin thickness, .

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 provides a polymer film having physical properties such as high durability, heat resistance, and low gas permeability, which can realize excellent airtightness even with a thin thickness, can be used as an inner liner film to lighten the tire and improve automobile fuel economy .

In the present specification, polyamide based repeating units; Polyether-based repeating units; An arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least two acyl functional groups; And an alkylene acyl repeating unit containing an alkylene group having 1 to 10 carbon atoms and at least two acyl functional groups.

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

In the present specification, an arylene group means a divalent functional group derived from arene. Also, in this specification, an alkylene group means a divalent functional group derived from an alkane. In the present specification, an acyl group means the remaining functional group by removing -OH from a carboxy group (-COOH) of a carboxylic acid, and is represented by the general formula RCO-.

In the present specification, alkyl (Alkyl) means a monovalent functional group derived from an alkane, and aryl means a monovalent functional group derived from arene.

According to one embodiment of the invention, polyamide based repeating units; Polyether-based repeating units; An arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least two acyl functional groups; And an alkylene acyl repeating unit containing an alkylene group having 1 to 10 carbon atoms and at least two acyl functional groups can be provided.

The present inventors proceeded with research on the material of the inner liner film to solve the limitations of rubber components such as butyl rubber or halobutyl rubber which were previously used by using the specific polymer film described above, , High temperature and the like, as well as high elasticity and low modulus characteristics, as well as excellent mechanical properties.

In particular, the copolymer may contain an alkylene group having 1 to 10 carbon atoms and an alkylene group having 1 to 10 carbon atoms, together with an arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least 2 or more acyl functional groups And an alkylene acyl repeating unit including two or more acyl functional groups, it is possible to obtain high airtightness and excellent moldability and high heat resistance and heat resistance when applied to an innerliner of a tire, , The physical properties may not be significantly changed during the tire forming process or the running process of the vehicle in which the film is repeatedly deformed and the rate of crystallization at a high temperature is relatively small so that the crystallization of the film itself due to the temperature rise and thus the breakage of the film are prevented .

Specifically, the above-mentioned arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least 2 acyl functional groups, an alkylene group having 1 to 10 carbon atoms and at least 2 or more acyl acyl) functional group may be 1: 1 to 1: 9, or 1: 1.2 to 1: 6, or 1: 1.3 to 1: 4.

An arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least 2 acyl functional groups, an alkylene group having 1 to 10 carbon atoms and at least 2 acyl functional groups Is less than 1: 1, heat resistance or thermal shock resistance may not be sufficiently secured, and physical properties of the polymer film may be lowered upon exposure to high temperature conditions of 100 占 폚 or more.

Also, the above-mentioned arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least 2 acyl functional groups, an alkylene group having 1 to 10 carbon atoms and an acyl group having at least 2 acyl ) Functional group is more than 1: 9, the airtightness and durability of the polymer film may be deteriorated or the elasticity or moldability of the polymer film may decrease together with the increase of the modulus of the polymer film.

The alkylene acyl repeating unit containing the alkylene group having 1 to 10 carbon atoms and the acyl functional group having at least 2 is preferably a dicarboxylic acid or poly-carboxylic acid containing an alkylene group having 1 to 10 carbon atoms. And may be derived from a raw material such as adipic acid used in the production of the polymer film, for example.

Specific examples of the alkylene acyl repeating unit containing the alkylene group having 1 to 10 carbon atoms and at least 2 or more acyl functional groups include repeating units represented by the following formula (1).

[Chemical Formula 1]

In Formula 1, R ₁ is a straight chain alkylene group having 1 to 10 carbon atoms or a branched chain alkylene group having 4 to 10 carbon atoms.

The copolymer contained in the polymer film may contain 0.1 to 20% by weight of the alkylene acyl repeating unit.

If the content of the alkylene acyl repeating units in the copolymer is too small, the heat resistance or thermal shock resistance may not be sufficiently secured, and when the polymer is exposed to a high temperature condition of 100 ° C or more, the physical properties of the polymer film may significantly deteriorate.

On the other hand, when the content of the alkylene acyl repeating units in the copolymer is too high, the content of the polyamide repeating repeating units or the polyether repeating units is decreased, and the airtightness and durability of the polymer film are lowered, The modulus may increase or the elasticity or moldability may deteriorate.

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 (2).

(2)

In Formula 2, 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.

On the other hand, if the content of arylene acyl repeating units in the copolymer is too high, the content of the polyamide repeating repeating units or polyether repeating units may be decreased and the airtightness and durability of the polymer film may be deteriorated, The modulus may increase or the elasticity or moldability may deteriorate.

On the other hand, the copolymer contained in the polymer film may include a polyamide-based repeating unit, and the polyamide-based repeating unit may include a repeating unit represented by the following formula (3) or (4).

(3)

In Formula 3, R ₂ 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 arylalkylene group means a divalent functional group including an aryl group and an alkylene group.

More preferably, R ₂ is a straight-chain or branched alkylene group having 4 to 8 carbon atoms.

[Chemical Formula 4]

In Formula 4, R ₃ is an arylene (arylene) group having 1 to 20 carbon atoms linear or branched alkylene group or C 6 -C 20 group, R ₄ is an alkylene group of a straight-chain or branched-chain 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 arylalkylene group means a divalent functional group including an aryl group and an alkylene group.

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 polyamide-based repeating units in terms of the residual amount excluding the polyether-based repeating units, the arylene acyl repeating units, and the components that can be optionally contained with the alkylene acyl repeating units .

The polyamide-based repeating unit may be derived from a precursor containing a substituted or unsubstituted dicarboxylic acid or a derivative of a dicarboxylic acid. The derivative of the dicarboxylic acid may include a diastereomer compound or a diamide compound having a chain or cyclic structure.

Specific examples of the substituted or unsubstituted dicarboxylic acid are not limited to a great extent, and examples thereof include 6-aminohexanoic acid and the like.

Further, examples of the substituted or unsubstituted dicarboxylic acid derivatives are not limited to a great extent. For example, a lactam-based compound, which is a diamide compound having a cyclic structure, can be used. Examples of the lactam-based compound are not particularly limited, but include, for example,? -Caprolactam and laurin lactam 12-aminododecanoic acid.

On the other hand, the copolymer contained in the polymer film may include a polyether-based repeating unit, and the polyether-based repeating unit may include a repeating unit represented by the following formula (5).

[Chemical Formula 5]

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

The content of the polyether repeating unit in the polymer 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-based repeating unit is less than 2% by weight based on the weight of the polymer film, the modulus of the polymer film becomes high, and the moldability of the tire may deteriorate or the physical properties may deteriorate due to repeated deformation. The flexibility of the copolymer contained in the copolymer can be reduced.

On the other hand, if the content of the polyether-based repeating unit exceeds 40 wt% with respect to the weight of the polymer film, the gas barrier required for the tire inner liner is poor, and the tire performance may deteriorate. 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. Further, the heat resistance and compatibility of the copolymer contained in the polymer film may be decreased.

The polyether-based repeating unit may be derived from a precursor having a weight average molecular weight of 500 to 10,000, or 600 to 3,000. Examples of the precursor include, but are not limited to, monomers, oligomers or polymers containing an ether bond, and specifically, polyoxyalkylene diamines.

The specific examples of the polyoxyalkylene diamine are not particularly limited, and examples thereof include polyoxyethylenediamine, polyoxypropylenediamine, polyoxytetramethylenediamine, and mixtures of two or more thereof.

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.

The polymer film may have a thickness of 30 mu m to 300 mu m, or 40 mu m to 250 mu m, or 40 mu m to 200 mu m.

The polymer film has a thermal shock resistance of 1500 KJ / g or more, or 1500 KJ / g to 3000 KJ / g, or 2000 KJ / g or more as measured by ASTM D6110 after heat treatment at 170 ° C for 1 hour and 100 ° C for 24 hours, g to 2600 KJ / g.

Specifically, when the polymer film is applied to a tire inner liner film, when the thermal shock resistance measured by ASTM D6110 is less than 1500 KJ / g after heat treatment at 170 ° C for 1 hour and 100 ° C for 24 hours, The physical properties may be deteriorated in a tire forming process or a vehicle running process in which deformation is caused.

Also, the oxygen permeability measured at a temperature of 23 캜 and a relative humidity of 55 RH% for 24 hours through the ASTM D 1434 method is not more than 500 cc / (㎡ 24 hr 揃 atm) or not more than 300 cc / (㎡ 24 hr 揃 atm ).

Specifically, when the oxygen permeability of the polymer film of this embodiment measured over 24 hours through the ASTM D 1434 method at a temperature of 23 ° C. and a relative humidity of 55 RH% exceeds 500 cc / (m 2 · 24 hr · atm) The gas barrier property of the polymer film is decreased, so it may be difficult to maintain the air pressure of the tire when the tire is used as an inner liner.

The copolymer may have a weight average molecular weight of 30,000 to 500,000, or 70,000 to 300,000, or 90,000 to 200,000. If the weight average molecular weight of the copolymer is less than 30,000, the polymer film may not have sufficient mechanical properties and heat resistance to be used as a tire inner liner film, and the polymer film for inner liner has sufficient gas barrier property It may be difficult to secure.

 When the weight average molecular weight of the copolymer exceeds 500,000, the modulus or degree of crystallization of the polymer film excessively increases upon heating at a high temperature, and it may be difficult to ensure the elasticity or elastic recovery rate to be provided as the film for inner liner.

An example of the method for measuring the weight average molecular weight is not limited, but can be determined by, for example, gel permeation chromatography (GPC). Specific details regarding the gel permeation chromatography (GPC) method may include all contents commonly known in weight average molecular weight measurement.

The melting point of the copolymer may be 180 ° C or higher, 185 ° C or higher, or 190 ° C or higher, for example, 180 ° C to 250 ° C, or 190 ° C to 240 ° C. If the melting point of the copolymer is too low, the film may melt at the time of application of the inner liner of the tire, or the air inside may be leaked to the outside due to repeated airtightness at high temperature.

Examples of the method of measuring the melting point are not limited, but can be obtained by using a differential scanning calorimeter (DSC), for example. The specifics of the differential scanning calorimetry (DSC) may include all commonly known melting point measurements.

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 together with the above-mentioned copolymer.

If the viscosity of the polyamide resin measured in a 96% solution of sulfuric acid 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. It may be difficult to secure physical properties such as airtightness or moldability which should be possessed as the inner liner film.

If the viscosity of the polyamide resin measured in a sulfuric acid 96% solution is more than 4.0, the modulus or viscosity of the polymer film to be produced may be unnecessarily high and it may be difficult to have appropriate moldability or elasticity as a tire inner liner have.

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 resins usable for the polymer film include 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 their N-alkoxyalkylates such as methoxymethylated 6-nylon, methoxymethylated 6,610-nylon or methoxymethylated 612-nylon, preferably nylon 6, nylon 66, nylon 46, nylon 11, nylon 12, nylon 610 or nylon 612 can be 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, the weight ratio of the polyamide based resin having a relative viscosity of 3.0 to 4.0 (96% solution of sulfuric acid) and the copolymer may be from 7: 3 to 3: 7.

Even when the polymer film contains 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-based repeating unit with respect to the total weight of the polymer film is 2 wt% to 40 wt%, 3 wt% to 35 wt%, or 4 wt% to 30 wt%.

The polymer film may further contain a heat resistant agent in an amount of 0.0001 wt% to 2.50 wt%, or 0.0005 wt% to 1.00 wt% based on the weight of the entire polymer film. If the content of the heat resistant agent is too small, the effect of improving heat resistance may be insignificant. If the content of the heat resisting agent is too high, the polymerization rate may decrease, the physical properties of the polymer film may be deteriorated, and the effect of improving the heat resistance depending on the use amount may be substantially eliminated.

Specific examples of the heat resisting agent include hindered phenol compounds, aromatic amine compounds, phosphorus compounds, inorganic compounds, polyamide compounds, polyether compounds, hindered amine compounds, or a mixture of two or more thereof . The heat resistant agent may be applied in the form of a powder or a liquid.

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 (TPP), 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.

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 change in physical properties of the polymer film itself is not significant.

When a mixture of CuI and KI is used as the heat resisting agent, it may be used in an amount of 0.05% by weight to 0.6% by weight based on the total weight of the polymer film. In addition, the content of copper (Cu) in the mixture of CuI and KI may be 5 to 10 wt%.

Particularly, when a mixture of CuI and KI is used, the content of the heat resisting agent used is greatly reduced (for example, 0.05 to 0.6% by weight in the polymer film) Heat resistance can be greatly improved.

Specific examples of the hindered amine compound include Bis (2,2,6,6-tetramethyl-4-piperidyl) sebaceate, bis (2,2,6,6- (tinuvin 770); Bis (1,2,2,6,6-tetramethyl-4-piperidyl) sebaceate) and methyl 1,2,2,6-tetramethyl- The reaction product (tinuvin 765) of 6,6-tetramethyl-4-piperidyl sebaceate (methyl 1,2,2,6,6-tetramethyl-4-piperidyl sebaceate); 1,6-hexanediamine, N, N'-bis (2,2,6,6-tetramethyl-4-piperidyl) , 6,6-tetramethyl-4-piperidyl) polymer, 2,4,6 trichloro-1,3,5-triazine, (Chimassorb 2020) of 2,2,6,6-tetramethyl-4-piperidinamine (N-butyl 2,2,6,6-tetramethyl-4-piperidinamine); Decanedioic acid, bis (2,2,6,6-tetramethyl-1-octyloxy-4-piperidyl) ) -4-piperidyl) ester, 1,1-dimethylethylhydroperoxide and octane (Tinuvin 123); Triazine derivatives (tinuvin NOR 371); Butanedioic acid, the reaction of dimethyl ester 4 hydroxy-2,2,6,6-tetramethyl-piperidine ethanol with dimethylester 4-hydroxy-2,2,6,6-tetramethyl-piperidine ethanol (Tinuvin 622), and the like.

More preferably, when the hindered phenolic compound is used as the heat resisting agent, gas barrier properties and long-term heat resistance can be greatly improved. Specifically, the above-mentioned specific polymer and the heat resistant agent are used in the polymer film so that even when the polymer film is left in a high temperature environment for a long time or exposed, the physical properties of the polymer film are not greatly changed, 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 above-mentioned adhesive layer is that it includes a specific resorcinol-formalin-latex (RFL) adhesive having a specific composition. As a conventional adhesive for innerliner of a tire, 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 from 2 to 32 wt%, or from 10 to 20 wt%, and from 68 to 98 wt%, or from 80 to 90 wt% of a condensate of resorcinol and formalin can do.

The condensate of the resorcinol and the formalin may be obtained by mixing the resorcinol and the formalin in a molar ratio of 1: 0.3 to 1: 3.0, or 1: 0.5 to 1: 2.5, followed by a condensation reaction. In addition, the condensation product of resorcinol and formalin 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 good adhesion and may be included in an amount of 32% by weight or less in order to ensure proper endothelial property .

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 cross-linking reaction with the rubber, and not more than 98% by weight for the chemical reaction with the polymer film and the rigidity of the adhesive layer.

The adhesive layer may have a thickness of 0.1 to 20 탆, or 0.1 to 10 탆, or 0.2 to 7 탆, or 0.3 to 5 탆, and may be formed on one surface or both surfaces of the polymer film .

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 polymer 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.

Examples of the method for producing the copolymer are not limited to a wide range. For example, the polyamide-based repeating units; Polyether-based repeating units; Arylene acyl repeat units; And an alkylene acyl repeating unit; or a reaction product at a reaction temperature of 100 ° C or higher.

In addition, the method of producing the polymer film is not limited, and a commonly known method for producing a polymer film can be used. For example, a raw material containing the above-mentioned copolymer or optionally a polyamide- The polymer film may be formed by supplying the solution to the die and melting and extruding the solution at 230 to 300 ° C.

The temperature at which the raw material is melted may be 230 캜 to 300 캜, or 240 캜 to 280 캜. 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 method for producing a polymer film may further include a step of extruding the melt-extruded raw material into a film having a thickness of 30 μm to 300 μm. 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.

The die gap of the extrusion die may be adjusted to 0.3 mm to 1.5 mm in order to more uniformly control the thickness of the polymer film layer in the range of 30 탆 to 300 탆.

If the die gap is too small in the production of the polymer film, the die shear pressure in 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, 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, so that it can be used as an inner liner film to lighten the tire and improve the automobile fuel economy, and to provide a polymer film having excellent durability, heat resistance and low gas permeability Can be provided.

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  1 to 3: Preparation of polymer film &gt;

Example 1

(1) Synthesis of Copolymer

A 5 L reactor was charged with 1.4 kg of? -Caprolactam, 600 g of polyoxypropylene diamine (molecular weight: about 2,000), 9.9 g of isophthalic acid, 35.1 g of adipic acid and 4 g of phenolic antioxidant, 80 g of water was added, Gt; 60 &lt; / RTI &gt;

The temperature of the reactor was raised to 240 캜, and the reaction was carried out at 60 rpm for 1 hour while maintaining a pressure of 14 kg / cm 2. 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 &lt; 2 &gt; for 210 minutes to complete the polymerization reaction.

After the completion of the polymerization reaction, the polymer was discharged by pressurization of 2 kg / cm 2 to prepare a polymer chip (P-1).

(2) Production of polymer film

The chip thus prepared was washed with water at 95 캜 for 24 hours to remove unreacted materials, and then vacuum dried at 100 캜 for 20 hours. The dried chips were extruded at a temperature of 250 ° C by a melt extruder to prepare a 120 μm thick polymer film.

Example  2

A 120 m thick polymer film was prepared in the same manner as in Example 1, except that 14.9 g of the isophthalic acid and 30.7 g of adipic acid were used.

Example  3

A 120 m thick polymer film was prepared in the same manner as in Example 1 except that 19.9 g of the isophthalic acid and 26.3 g of adipic acid were used.

< Comparative Example  1: Production of polymer film &gt;

Comparative Example 1

A 120 탆 polymer film was prepared in the same manner as in Example 1 except that 0 g of the isophthalic acid and 43.8 g of adipic acid were used.

< Experimental Example  : Example  And In the comparative example  Measurement of Physical Properties of the Polymer Film Obtained>

1. Melting point and crystallization temperature (占 폚)

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

2. Relative viscosity (dl / g)

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

3. Tensile strength and tensile modulus ( MPa )

The specimen (width 15 mm) of each of the polymer films obtained in Examples 1 to 3 and Comparative Example 1 was measured for ASTM 882, and the gage length was set to 50 mm. Then, a tensile strength and a tensile strength The elastic modulus was measured

4. Oxygen permeability [ cc / (㎡ * 24 hr * ATM )]

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

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

EXAMPLES AND COMPARATIVE EXAMPLES Experimental Example Results of Polymer Film division Melting point
(° C) Crystallization temperature
(° C) Relative viscosity
(Dl / g) The tensile strength
(MPa) Tensile modulus
(MPa) Oxygen permeability
[cc /
(M &lt; 2 &gt; * 24hr * atm)] Before heat treatment After heat treatment Before heat treatment After heat treatment Example 1 214.73 58.40 1.46 42.45 36.49 11.78 19.29 250 Example 2 214.80 59.60 1.44 41.46 37.72 13.24 21.44 240 Example 3 214.84 59.63 1.41 46.44 41.43 14.24 30.33 240 Comparative Example 1 216.70 68.73 1.45 47.74 35.64 15.76 41.86 540

As shown in Table 1, it was confirmed that the films obtained in Examples 1 to 3 had a relatively low melting point and crystallization temperature as compared with the polymer film obtained in Comparative Example 1, and the tensile strength and tensile modulus retention after heat treatment were relatively low High.

In addition, it was confirmed that the films obtained in Examples 1 to 3 had a lower oxygen permeability than the film of Comparative Example 1, so that high airtightness can be secured when used as an inner liner.

5. Evaluation of heat resistance

The films obtained in Examples 1 and 3 and the polymer films obtained in Comparative Example 1 were heat-treated in a UL oven at 170 ° C for 1 hour and at 100 ° C 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 division Amorphous peak intensity
(1166 cm ^-1 ) Crystalline peak intensity (1203 cm ^-1 ) Crystalline peak intensity /
Amorphous peak intensity Relative crystallinity (%) Example 1 Before heat treatment 0.201 0.197 0.980 49.497 After heat treatment 0.197 0.201 1.020 50.503 Example 2 Before heat treatment 0.212 0.204 0.962 49.038 After heat treatment 0.202 0.218 1.079 51.905 Example 3 Before heat treatment 0.225 0.215 0.956 48.864 After heat treatment 0.218 0.232 1.064 51.556 Comparative Example 1 Before heat treatment 0.221 0.254 1.149 53.474 After heat treatment 0.204 0.297 1.456 59.281

As shown in Table 2, in the polymer films of Examples 1 to 3, the relative crystallinity, which is the intensity of the crystalline peak versus the intensity of the amorphous peak, was found to be less than 52% both before and after the heat treatment. On the other hand, the polymer film of Comparative Example 1 had a relative crystallinity of more than 52% after the heat treatment, and the relative crystallinity significantly increased especially after the heat treatment.

Impact strength before and after heat treatment of polymer film division Thermal shock resistance (KJ / g) Before heat treatment After heat treatment Retention rate (%) Example 1 3680 2524 68.59 Example 2 3970 2674 67.36 Example 3 4007 2321 57.92 Comparative Example 1 3517 1244 35.37

As shown in Table 3, it was confirmed that the polymer films of Examples 1 to 3 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 film of Comparative Example 1 was found to have a thermal shock resistance lower than 1500 KJ / g after the heat treatment and a thermal shock resistance retention of less than 40%.

In other words, the polymer films of Examples 1 to 3 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 damage to the film can be prevented.

Claims (19)

Polyamide repeating repeats; Polyether-based repeating units; An arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least 2 or more acyl functional groups; And an alkylene acyl repeating unit containing an alkylene group having 1 to 10 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,
An arylene acyl repeating unit containing an arylene group having 6 to 20 carbon atoms and at least 2 or more acyl functional groups; And an alkylene acyl repeating unit containing an alkylene group having 1 to 10 carbon atoms and at least two acyl functional groups is in a molar ratio of 1: 1 to 1: 9.
The method according to claim 1,
A thermal shock resistance of 1500 KJ / g or more as measured by ASTM D6110 after heat treatment at 170 占 폚 for 1 hour and 100 占 폚 for 24 hours.
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 500 cc / (㎡ 24 hr 揃 atm).
The method according to claim 1,
Wherein the alkylene acyl repeating unit comprises a repeating unit represented by the following formula (1):
[Chemical Formula 1]

In Formula 1, R ₁ is a straight or branched alkylene group having 1 to 10 carbon atoms.
The method according to claim 1,
Wherein the copolymer comprises 0.1 wt% to 20 wt% of the alkylene acyl repeat unit.
The method according to claim 1,
Wherein the arylene acyl repeating unit comprises a repeating unit represented by the following formula (2): &lt; EMI ID =
(2)

In Formula 2, 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 repeat unit.
The method according to claim 1,
Wherein the copolymer has a weight average molecular weight of 30,000 to 500,000.
The method according to claim 1,
Wherein the copolymer has a melting point of 180 占 폚 or higher.
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 polymer film further comprises a polyamide resin having a relative viscosity (96% solution of sulfuric acid) of 3.0 to 4.0.
14. The method of claim 13,
Wherein the weight ratio of the polyamide based resin having a relative viscosity of 3.0 to 4.0 (96% solution of sulfuric acid) and the copolymer is 7: 3 to 3: 7.
The method according to claim 1,
Wherein the polymer film has a thickness of 30 탆 to 300 탆.
The method according to claim 1,
And further comprising 0.0001% to 2.5% by weight of a heat resistant agent.
17. The method of claim 16,
Wherein the heat resistant agent is a polymer comprising at least one compound selected from the group consisting of a hindered phenol compound, an aromatic amine compound, a phosphorus compound, an inorganic compound, a polyamide compound, a polyether compound and a hindered amine compound film.
The method according to claim 1,
Wherein the polymer film further comprises an adhesive layer formed on at least one side of the polymer film and including a resorcinol-formalin-latex (RFL) -based adhesive.
19. The method of claim 18,
Wherein the adhesive layer has a thickness of 0.1 占 퐉 to 20 占 퐉.