KR20160038514A - Copolymer andn polymer film - Google Patents

Abstract

The present invention relates to a copolymer comprising: 20 to 90 wt% of a polyamide-based repetitive unit; 2 to 45 wt% of an alkylene oxide repetitive unit having a straight chain or a branched chain of 2 to 10 carbon atoms; and 4 to 38 wt% of a dialkyl siloxane repetitive unit having a straight chain or a branched chain of 1 to 4 carbon atoms, and to a polymer film comprising a base material film including the copolymer, wherein the polymer film has high durability and high thermal resistance.

Description

COPOLYMER AND POLYMER FILM < RTI ID = 0.0 >

The present invention relates to a copolymer and a polymer film, and more particularly, to a copolymer and a polymer film which have high stability at a high temperature without changing their physical properties and morphology, and which can secure a relatively high level of impact strength and excellent airtightness The present invention relates to a polymer film having an improved lubrication property, high heat resistance and high fatigue resistance, as well as excellent moldability.

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 is intended to provide a copolymer which has high stability at high temperature and whose properties and form are not greatly changed, and which can secure a relatively high level of impact strength.

In addition, the present invention realizes excellent airtightness even with a thin thickness, and can be used as an inner liner film to reduce the weight of a tire and improve automobile fuel economy. In addition, the present invention can provide a polymer having high durability, high heat resistance and high fatigue resistance Film.

In the present specification, 20 to 90% by weight of a polyamide-based repeating unit; 2 to 45% by weight of a linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms; And 4 to 38% by weight of a straight or branched chain dialkylsiloxane repeating unit having 1 to 4 carbon atoms.

Further, in the present specification, a polymer film comprising a base film containing the copolymer is provided.

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

According to one embodiment of the invention, the polyamide-based repeating unit is 20 wt% to 90 wt%; 2 to 45% by weight of a linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms; And 4 to 38% by weight of a straight or branched chain dialkylsiloxane repeating unit having 1 to 4 carbon atoms.

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 properties and shape of the inner liner film do not change significantly A novel copolymer having high stability, a relatively high level of impact strength can be secured, excellent mechanical properties with high elasticity and low modulus properties, and the invention is completed.

Particularly, the copolymer contains a linear or branched dialkylsiloxane repeating unit having 1 to 4 carbon atoms, has a high stability at a high temperature and does not significantly change its physical properties and form, can secure a relatively high level of impact strength And thus the inner liner of the pneumatic tire provided with the copolymer has a high durability and endothelial property because it has high airtightness and does not change in physical properties or shape even during tire forming process or automobile running process can do.

The copolymer may contain from 4 to 38% by weight, or from 5 to 30% by weight, of straight or branched chain dialkylsiloxane repeating units having from 1 to 4 carbon atoms.

If the content of the linear or branched dialkylsiloxane repeating unit having 1 to 4 carbon atoms in the copolymer is too small, it may be difficult to ensure the heat resistance or thermal decomposition temperature of the copolymer to a sufficiently high level, The retention ratio of physical properties or morphology before and after stretching can be significantly lowered. When the content of the linear or branched dialkylsiloxane repeating unit having 1 to 4 carbon atoms in the copolymer is too large, it is preferable that the dialkylsiloxane repeating unit, the polyamide repeating unit and the alkylene oxide The bonding between the repeating units may not be smooth, so that synthesis into a copolymer may not be easy, and reactivity or mechanical properties may deteriorate during polymerization.

Specifically, the straight-chain or branched-chain dialkylsiloxane repeating unit having 1 to 4 carbon atoms may include a repeating unit represented by the following formula (4).

[Chemical Formula 4]

In the general formula (3), R ₈ and R ₉ may be the same or different from each other and are each methyl or ethyl, and n is an integer of 5 to 50, or an integer of 10 to 30, or an integer of 13 to 27.

When n is too small in the repeating units of the formula (4), the heat resistant impact strength of the copolymer of the above embodiment or the polymer film produced therefrom may not be improved or the modulus improvement effect may be insignificant. When n is too large in the repeating units of the above formula (4), the proportion of the copolymer of this embodiment retaining its physical properties and shape at high temperature may be lowered, and the reactivity may be poor or the reactivity may be difficult to control.

On the other hand, the polyamide-based 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. More preferably, in Formula 1, R ₁ may be an alkylene group having 3 to 6 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 polymer to be finally produced or the copolymer. Specifically, the copolymer is a copolymer of a linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms and a linear or branched dialkylsiloxane repeating unit having 1 to 4 carbon atoms, And may contain 20 to 90% by weight and 55 to 85% by weight of the polyamide-based repeating unit.

The linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms 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 2 to 10 carbon atoms, n is an integer of 5 to 50, R ₆ and R ₇ may be the same or different and are each a direct bond, -O -, -NH-, -COO- or -CONH-.

The linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms 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.

If n is too small in the repeating units of the above formula (3), the copolymer may not adequately suppress the growth of large crystals at a high temperature or lower the modulus. If n is too high in the repeating units of the above formula (3), the durability of the copolymer may be lowered, and the gas permeability of the polymer film produced using the copolymer may be greatly increased.

The copolymer of this embodiment comprises from 2% to 45%, or from 5% to 40%, or from 8% to 35% by weight of a linear or branched alkylene oxide repeat unit having from 2 to 10 carbon atoms .

When the content of the linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms in the copolymer is too low, the modulus of the polymer film produced using the copolymer and the copolymer becomes high, The physical properties of the copolymer or the polymer film may be greatly deteriorated. In addition, if the content of the linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms in the copolymer is too high, the elasticity of the copolymer may be excessively increased to make it difficult to produce a uniform film , The polymer film produced from the copolymer is poor in gas barrier property required as a tire inner liner, so that tire performance may be deteriorated. The reactivity to the adhesive may be lowered and the polymer film may be difficult to easily adhere to the carcass layer of the inner liner.

The copolymer may have a weight average molecular weight of 50,000 to 300,000, or 70,000 to 250,000, or 90,000 to 200,000. The copolymer has a weight average molecular weight of less than 50,000 and mechanical properties and heat resistance sufficient to use the copolymer as the material of the inner liner of the pneumatic tire 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 copolymer excessively increases upon heating at a high temperature, so that it may be difficult to secure the elasticity or elastic recovery rate to be provided as the film for inner liner.

The copolymer may have a thermal decomposition temperature of 410 ° C or more, 412 ° C or more, or 408 ° C to 430 ° C. The copolymer may have improved pyrolysis temperature and heat resistance by including the above-mentioned straight or branched chain dialkylsiloxane repeating unit having 1 to 4 carbon atoms.

The pyrolysis temperature can be measured using a thermogravimetric analyzer (TGA) or the like, for example, a temperature at which the thermogravimetry of the copolymer changes by 5% or more.

The copolymer may further include an alkylene acyl repeating unit containing an alkylene group having 1 to 10 carbon atoms and at least two acyl functional groups.

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 copolymer, 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 (5).

[Chemical Formula 5]

In Formula 5, R ₈ is a straight or branched alkylene group having 1 to 10 carbon atoms.

The copolymer may contain 0.001 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 the physical properties of the copolymer may deteriorate when exposed to high temperature conditions of 100 ° C or more. When the content of the alkylene acyl repeating unit in the copolymer is too high, the content of the polyamide-based repeating unit or the polyether-based repeating unit is reduced, and thus the polymer film produced from the copolymer or the copolymer has an airtightness The durability may be lowered, or the modulus of the copolymer or the polymer film may increase, or the elasticity or moldability may be deteriorated.

On the other hand, the method of synthesizing the copolymer is not limited to a wide range, and the polyamide-based repeating unit; A linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms; And a precursor or a reactant capable of forming a linear or branched dialkylsiloxane repeating unit having 1 to 4 carbon atoms at a reaction temperature of 100 ° C or higher.

On the other hand, according to another embodiment of the present invention, a polymer film comprising a base film containing the above-mentioned copolymer can be provided.

As described above, the copolymer contains 20 to 90% by weight of a polyamide-based repeating unit; 2 to 45% by weight of a linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms; And 4 wt% to 38 wt% of a straight or branched chain dialkylsiloxane repeating unit having 1 to 4 carbon atoms.

More specific details regarding the polyamide-based repeating unit, the straight-chain or branched alkylene oxide repeating unit having 2 to 10 carbon atoms, the straight-chain or branched-chain dialkylsiloxane repeating unit having 1 to 4 carbon atoms, and the copolymer are described in The above-mentioned contents relating to the copolymer of the embodiment.

The polymer film including the above-mentioned copolymer has a high stability not only at room temperature but also at a high temperature, the physical properties and shape of which are not greatly changed, can secure a relatively high level of impact strength, And changes in physical properties and shape are not so large even in the course of traveling in a car, so that durability and endothelial characteristics can be secured.

The polymer film may be used as an inner liner of a pneumatic tire.

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).

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 or nylon 46 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 (96% solution of sulfuric acid) of 3.0 to 4.0: the weight ratio of the copolymer may be from 7: 3 to 1: 9.

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.

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

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 raw material containing the above-mentioned copolymer or, optionally, a raw material further containing a polyamide based resin is supplied to an extrusion die and melted and extruded at 200 ° C or higher or 230 ° C to 300 ° C to form a polymer film . 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, but if it is too high, carbonization or decomposition may occur to deteriorate the physical properties of the film, and bonding between the polyether-based repeating units may occur or orientation may occur in the fiber array direction .

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, a copolymer capable of securing a relatively high level of impact strength with high stability at a high temperature, which does not greatly change its physical properties and shape, and an airtightness even at a thin thickness are realized, And the automobile fuel economy can be improved, and a polymer film having physical properties such as high durability, high heat resistance and high fatigue resistance can be provided along with excellent moldability.

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.
Fig. 2 shows the 1 H NMR data of the copolymer synthesized in Example 2. Fig.

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 : Synthesis of Copolymer and Production of Polymer Film]

Example  One

(1) Synthesis of Copolymer

A 2 L reactor was charged with 700 g of? -Caprolactam, 250 g of polyoxytetramethylenediamine (molecular weight: about 1,100), 50 g of hydroxyl terminated polydimethylsiloxane (hydroxy terminated, weight average molecular weight: 1,000 g / mol) Adipic acid having the same number of moles as the sum of the diamine and polydimethylsilic acid was added thereto, 14 g of water was added, and the mixture was stirred at 150 DEG C and 80 rpm. Then, the temperature of the reactor was raised to 250 DEG C, and the reaction was carried out at 80 rpm for 1 hour while maintaining a pressure of 0.33 MPa. Thereafter, the pressure of the reactor was gradually removed for 30 minutes to make atmospheric pressure, and the reaction was completed in this state, and the final reaction product was prepared in the form of chips. 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.

 (2) Production of polymer film

The dried chips were extruded at a temperature of 250 캜 by a melt extruder and a 120 탆 polymer film was prepared through a T-die.

Example  2

As shown in Table 1 below, the amount of polyoxytetramethylenediamine used is reduced A copolymer was synthesized in the same manner as in Example 1 except that the amount of the hydroxyl group-terminated polydimethylsiloxane was increased to prepare a polymer film having a thickness of 120 탆.

Example  3 and 4

A copolymer was synthesized in the same manner as in Example 2 except that the amount of polyoxytetramethylenediamine used was increased and the amount of the hydroxyl group-terminated polydimethylsiloxane was increased as shown in Table 1 below to prepare a 120 탆 polymer film.

Comparative Example 1

A copolymer was synthesized in the same manner as in Example 1, except that 50 g of polyoxytetramethylenediamine was used instead of 50 g of the hydroxyl group-terminated polydimethylsiloxane (hydroxy terminated, weight average molecular weight 1000 g / mol) And a polymer film having a thickness of 120 탆 was prepared.

Comparative Example 2

A copolymer was synthesized in the same manner as in Example 1 except that the amount of polyoxytetramethylenediamine used was reduced and 400 g of hydroxyl terminated polydimethylsiloxane was used as shown in Table 1 below to prepare a 120 탆 polymer film.

Comparative Example 3

A copolymer was synthesized in the same manner as in Example 1 except that the amount of polyoxytetramethylenediamine used was increased and 30 g of hydroxyl terminated polydimethylsiloxane was used as shown in Table 1 below to prepare a polymer film having a thickness of 120 탆.

Comparative Example 4

A copolymer was synthesized in the same manner as in Comparative Example 2, except that the weight-average molecular weight of the hydroxyl group-terminated polydimethylsiloxane used was changed as shown in Table 1, to prepare a 120 탆 polymer film.

Comparative Example 5

A copolymer was synthesized in the same manner as in Comparative Example 3, except that the weight-average molecular weight of the hydroxyl group-terminated polydimethylsiloxane used was changed as shown in Table 1, to prepare a 120 탆 polymer film.

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

Experimental Example 1 : Glass transition temperature [Tg (占 폚)]

The glass transition temperatures of the polymer films obtained in the above Examples and Comparative Examples were confirmed using Dynamic Mechanical Thermal Spectroscopy (DMTS, manufacturer GABO Qualimeter, Explexor 500N).

Experimental Example 2 : Pyrolysis temperature [Td (占 폚)]

The thermal decomposition temperature of the polymer film obtained in the above Examples and Comparative Examples was measured by a thermogravimetric analyzer (TGA). Specifically, the temperature at which the thermal weight of the polymer film changed by 5% or more was determined as the thermal decomposition temperature.

Experimental Example 3 : Heat Shock Impact Strength ( KJ / g)

The polymer films obtained in the above Examples and Comparative Examples were classified before and after the heat treatment, and the heat treatment was conducted in a thermal aging tester at 170 ° C for 1 hour. Each of the films was measured for impact strength before and after heat resistance using a Pendulum Impact Tester (manufactured by Zwick / Roell, product name: HIT 5.5P) according to ASTM D256.

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

In the synthesis of the copolymer, Copolymer Tg
(° C) Copolymer Td
(° C) Thermal shock resistance (KJ / g) Thermoelectric conversion (KJ / g) After heat-resisting (KJ / g) Retention rate (%) Caprolactam content (wt%) PTMODA content
(wt%) PDMS molecular weight
(g / mol) PDMS content
(wt%) Example 1 70 25 1000 5 -95, -80 412 3400 2345 68.97 Example 2 70 20 1000 10 -99, -84 415 3347 2418 72.24 Example 3 70 20 3000 10 -98, -78 418 3557 2257 63.46 Example 4 70 20 500 10 -96, -77 410 3568 2213 62.02 Comparative Example 1 70 30 - - -65 406 3328 1790 53.78 Comparative Example 2 60 0 1000 40 - - - - - Comparative Example 3 70 27 1000 3 -94, -70 407 3588 1983 55.27 Comparative Example 4 60 0 3000 40 - - - - - Comparative Example 5 70 27 500 3 -89, -67 406 3385 1814 53.59

- PDMS: hydroxyl-terminated polydimethylsiloxane

- PTMODA: polyoxytetramethylenediamine

As shown in Table 1, the polymer film obtained in the examples exhibited a glass transition temperature in a relatively low temperature range as compared with the polymer film obtained in the comparative example, having excellent physical properties in a low temperature region, exhibiting a relatively high thermal decomposition temperature, Impact strength and heat resistance.

In addition, it was confirmed that the polymer film obtained in the Examples had a heat-resistant impact strength of 2200 KJ / g or more and a thermal shock resistance retention ratio of 60% or more even after the heat treatment. On the contrary, the polymer film of the comparative example was found to have a thermal shock resistance lower than 2200 KJ / g and a thermal shock resistance retention of less than 60% after the heat treatment.

That is, the polymer film of the above-mentioned embodiment has high heat resistance and heat resistance, and when used as an inner liner film, the physical properties may not be significantly changed even during a tire forming process or an automobile running process in which repeated deformation occurs at a high temperature. The ratio 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 (14)

20 to 90% by weight of a polyamide-based repeating unit;
2 to 45% by weight of a linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms; And
4 to 38% by weight of a linear or branched dialkylsiloxane repeating unit having 1 to 4 carbon atoms.
The method according to claim 1,
Wherein the thermal decomposition temperature of the copolymer is 410 DEG C or higher.
The method according to claim 1,
Wherein the polyamide-based 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 linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms comprises a repeating unit represented by the following formula:
(3)

In Formula 3,
R < ₅ > is a linear or branched alkylene group having 2 to 10 carbon atoms,
n is an integer from 5 to 50,
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 straight or branched chain dialkylsiloxane repeating unit having 1 to 4 carbon atoms comprises a repeating unit of the following formula:
[Chemical Formula 4]

In Formula 3,
R ₈ and R ₉ may be the same or different and are each methyl or ethyl, and n is an integer of from 5 to 50.
The method according to claim 1,
55 to 85% by weight of polyamide-based repeating units;
8 to 35% by weight of a linear or branched alkylene oxide repeating unit having 2 to 10 carbon atoms; And
And 5 to 30% by weight of a straight or branched chain dialkylsiloxane repeating unit having 1 to 4 carbon atoms.
The method according to claim 1,
Wherein the copolymer further comprises an alkylene acyl repeating unit containing an alkylene group having 1 to 10 carbon atoms and at least two acyl functional groups.
A polymer film comprising a substrate film comprising the copolymer of claim 1.
9. The method of claim 8,
Polymer film used as inner liner of pneumatic tire.
9. The method of claim 8,
Wherein the base film has a thickness of 30 占 퐉 to 300 占 퐉.
9. The method of claim 8,
Wherein the base film further comprises a polyamide resin having a relative viscosity (a 96% solution of sulfuric acid) of 3.0 to 4.0.
9. The method of claim 8,
Wherein the weight ratio of the polyamide-based resin to the copolymer is from 7: 3 to 1: 9.
9. The method of claim 8,
Further comprising an adhesive layer formed on at least one side of the base film and comprising a resorcinol-formalin-latex (RFL) -based adhesive.
14. The method of claim 13,
Wherein the adhesive layer has a thickness of 0.1 占 퐉 to 20 占 퐉.

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