WO2015102339A1

WO2015102339A1 - Polyester film having high heat resistance

Info

Publication number: WO2015102339A1
Application number: PCT/KR2014/012975
Authority: WO
Inventors: 이세철; 정다우; 김수희; 허영민; 이장원; 기정희; 김상일; 이득영
Original assignee: 에스케이씨 주식회사
Priority date: 2013-12-30
Filing date: 2014-12-29
Publication date: 2015-07-09
Also published as: TW201546172A; TWI685539B

Abstract

The present invention relates to a polyester film comprising a polyester resin comprising (i) a constituent unit derived from a diol component containing 90 mol% or more of 1,4-cyclohexanedimethanol and (ii) a constituent unit derived from a dicarboxylic acid component containing 3-25 mol% of isophthalic acid, wherein the haze is 2% or less, the heat shrinkage is 3% or less in both longitudinal and transverse directions after maintenance at 150°C for one hour, and the change in haze is less than 1%. The polyester film of the present invention is transparent, shows remarkable heat resistance, and when exposed to high temperature and humidity, exhibits excellent hydrolysis resistance such as a property capable of maintaining intrinsic remarkable film properties for a long time and does not have physical property deterioration caused by crystallization at a high temperature, and thus can be useful as an optical film for display.

Description

Polyester film having high heat resistance

Field of technology

The present invention relates to a polyester film that is transparent and excellent in heat resistance and suitable as an optical film.

Background

Various types of optical films are applied to liquid crystal displays (LCDs) or organic light emitting diode (OLED) displays, which are widely used as flat panel displays.

Since the LCD is a light-receiving device that displays an image by controlling the amount of debt coming from the outside, a back light unit (BLU) in the form of a back light source capable of maintaining uniform brightness on the screen premises is required, and the backlight As a light source of the unit, a small fluorescent lamp or a light emitting diode (LED) is mainly used. Since the small fluorescent lamp or LED is a line light source or a point light source, the BLU is diverted to a light guide plate that converts it into a uniform surface light source, and a reflector to reduce light loss by reflecting a debt exiting to the lower side of the light guide plate, and to the upper axis of the light guide plate. by scattering the debt give Mask an cancellations (defect) condensing a diffusion sheet, LCD size to diffuse the light ^[[ara diffused uniformly debt to the optical sheet of various kinds of such a prism sheet to make a debt of strong intensity In addition, it is used in the form of a surface light source, and in addition, various kinds of plates and films are used to direct debt emitted from the light source toward the LCD panel. In addition, in the case of OLED, optical films, such as a circularly polarizing plate for external light blocking, in order to prevent the fall of contrast by external light, are used.

However, the polyester film mainly used as an optical film of the conventional display device has a problem of heat resistance due to a low glass transition temperature (Tg), and in particular, at a high temperature, oligomer elution occurs, thereby causing a problem of coating an oligomer blocking layer on the film. . In addition, the tendency of the hydrolysis of the polyester at high temperatures is very important for durability in this application. With regard to iodine, it has long been known that the lower carboxyl end group content (CEG content) can lower the hydrolysis, but precise process control is required to produce polyesters with low carboxyl end group content. And subsequent solid phase polymerization and the like (US Pat. No. 3,051,212). On the other hand, poly (1,4-cyclohexanedimerylene terephthalate) (PCT) derived from 1,4-cyclohexanedimethanol (CHDM) is a transparent, heat resistant, hydrolytically stable polyester Known as However, when the content of 1,4-cyclohexanedimethanol (CHDM) contained in the PCT is high, the crystallization rate is high, making extrusion difficult during film production, and the brittleness of the produced PCT film is high. There is a problem that high, causing a decrease in physical properties due to crystallization at high temperatures.

Therefore, it is necessary to develop a polyester film which is excellent in heat resistance, hydrolytically stable, and which is free from physical property deterioration due to crystallization at high temperature.

Summary

Accordingly, it is an object of the present invention to provide a polyester film suitable for a display optical film that is transparent, excellent in heat resistance, stable hydrolysable, and free from physical property deterioration by crystallization at a high temperature, and a method of manufacturing the same.

In order to achieve the above object, the present invention is 0) the structure derived from a diol component containing 90 mol ⁰ / ᄋ or more nucleic acid 1,4-cyclohexane dimethanol danwoo i, and (Π) 3 to 25 mole ^_0/0 It comprises a polyester resin comprising a structural unit derived from a dicarboxylic acid component containing isophthalic acid of, has a haze of 2% or less, heat shrinkage after holding for 1 hour at 150 ^o C both in the longitudinal and transverse directions It provides a polyester film having 3% or less and less than 1% haze defense. To another aspect of the present invention is (1) (i) a diol component comprising a diethanolamine-hexane to 90 mole ^_0/0 or more 1,4-cyclohexane, and () 3 to 25 mole% of isophthaloyl ralsan of Preparing a polyester resin by polymerizing a dicarboxylic acid component;

(2) melting and extruding the polyester resin to form a sheet; (3) biaxially stretching the molded sheet in the longitudinal and transverse directions; And (4) thermally setting the axially stretched sheet. The present invention also provides an optical film comprising the polyester film. The present invention also provides a display device comprising the polyester film.

The polyester film of the present invention is transparent and excellent in heat resistance, and exhibits excellent hydrolysis resistance such as being able to maintain inherent excellent film properties even when exposed to long periods of time, and even at high temperatures and humidity. It is to provide a polyester film suitable as an optical film for display without deterioration in physical properties.

Brief description of the drawings

1 is an SEM image of a film prepared in Example.

2 is an SEM photograph of a film prepared in Comparative Example D1. 3 is an SEM photograph of a film prepared in Comparative Example D5.

Detailed description of the invention

Hereinafter, the present invention will be described in more detail.

The polyester film according to the present invention is a polyester comprising a structural unit derived from (0 diol component and (ii) a dicarboxylic acid component. Resin tool is included. Such a polyester resin may be induced by polymerization after the ester exchange reaction between the diol component and the dicarboxylic acid component.

The diol component is 90 mol ^_0/0 over lead i 1,4-cyclohexanedimethanol comprises the constitutional unit derived from methanol (CHDM), preferably CHDM to 98 mole ^_0/0, more preferably at least 99 mole It comprises ^_0/0 above. The diol component may further include a diol component other than CHDM. Specific examples of the diol component which may be further included as such are ethylene glycol, 1,3-propanediol, 1,2-octanediol, 1,3-octanediol, 2,3-butanediol, 1,3-butanediol , 1,4-butanediol, 1,5-pentanediol, 2,2-dimeryl-1,3-propanediol (neopennylglycol), 2-butyl-2-eryl-1,3-propanediol , 2,2-diaryl-1,5-pentanediol, 2,4-diaryl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,1-dimeryl-1, 5-pentanediol and mixtures thereof are mentioned. The higher the ratio of CHDM contained in the diol component, the higher the Tg of the polymer, the better the heat resistance and the higher the hydrolysis resistance. However, since the structure of CHDM increases the crystallinity, extrusion or film Determination can occur when drawing. Accordingly, the polyester resin of the present invention contains isopral acid as the dicarboxylic acid component to lower the crystallization rate. When the isophthalic acid is included, the crystallization rate, which is excessively high as CHDM is included, may be lowered, and the handleability of the polymerizer may be increased by lowering the melting temperature (Tm) of the polymerizing agent. The Tg of the agent can be lowered to lower thermal properties such as heat resistance.

In the dicarboxylic acid component is the isophthalic acid with 3 to 25 mol%, relief write down to 5 to 20 mole ^_0/0, and if in more relief typically 5 to 18 moles of even more specifically 5 ^_0/0, 15 mole May contain%. Alternatively, the dicarboxylic acid component is the isophthaloyl LAL acid 10 mol ^_0/0 or less, remedies typically 0 mol ^_0/0 larger than 7 mole ^_0/0 or less, and more relief typically 0 mol ^_0/0 ultrahigh a 5 mol It can comprise an amount of not more than ^_0/0. The dicarboxylic acid component may also include terephthalic acid.

In particular, the dicarboxylic acid component is 75 to 97 mol%, terephthalic acid, The expulsion of 80 to 95 mole ^_0/0, more particularly 82 to 95 mole ^_0/0, than ever relief may further comprise 85 to 95 mole%. Alternatively, the dicarboxylic acid component is 90 mol of the rim Lev ralsan 80 mole ^_0/0 or more, or 90 mol ^_0/0 or more, for example 80 mole ^_0/0 100 mole ⁰ / less than _0, more relief enemy % or more and less than 100 mole ^_0/0, can be more specifically hamhal included by 93 mol% or more and 100 mole ⁰ / less than _0, more typically relief 95 mole ^_0/0 100 mol is less than ^_0/0.

That is, the polyester resin may be a copolyester resin. In addition, as said dicarboxylic acid component, Aromatic dicarboxylic acid, such as a diaryl terephthalic acid, naphthalenedicarboxylic acid, orthophthalic acid; Aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid; Alicyclic dicarboxylic acid; And it may further include one or more selected from the group consisting of these esterified products. Accordingly, the polyester resin may include 1,4-cyclohexanedimerylene terephthalate, or 1,4-cyclonucleic acid dimethylene isophthalate terephthalate as a main repeating unit.

The polyester film according to the invention has an intrinsic viscosity (at 25 ° C) of 6 to 1.2 for filming and preferably has a weight average molecular weight of 30,000 to 50,000 g / mol, in particular 30,000 to 40,000 g / mol. Do.

The polyester film may be one containing fine particles in a polyester resin. When the fine particles are included, the running property and the blocking resistance of the polyester film may be improved. The fine particles may be, for example, inorganic particles such as colloidal silica, titanium oxide, aluminum oxide, coral zirconia or calcium carbonate, or organic particles such as crosslinked polyester particles, crosslinked polystyrene particles, or other crosslinked polymer particles. , 1 type may be used, or 2 or more types may be used together.

The polyester resin may comprise 200 to 3,000 ppm, preferably 400 to 1,500 ppm of spherical monodisperse particles. By including the spherical monodisperse particles to increase the sulphability of the polyester film, self-contacting of the polyester film It can solve the difficulty of winding up. When the content of the particles satisfies the range of 400 to 1,500 ppm, the friction coefficient of the film can be appropriately lowered without excessive rise in haze, and thus the winding property of the film can be improved. The spherical monodisperse particles is from 0.1 to 2.5 μη, preferably from 0.1 to 2.0 μ ^(may have a mean particle size of η, a ratio of the lead 5 to 1.2, preferably from 0.8 to 1.2, more Wook preferably 0.8 The particle diameter ratio may be expressed as the ratio of the long diameter I average value of the spherical monodispersed particles to the average value of the short diameter.

From 0.1 to 2.5, from 0.8 to 1.2 | In the case of having a particle size ratio, the coefficient of friction of the film can be set to 0.8 or less while preventing pinholes from occurring and breaking or dispersing to increase the haze. The spherical monodisperse particles may be inorganic particles or organic particles, but preferably inorganic particles, for example, may be at least one selected from the group consisting of spherical silica, spherical titanium oxide, and spherical zirconium. In general, when the particles are added to the finished polyester resin, there is a problem in dispersibility, but the polyester film of the present invention includes spherical monodisperse particles having an average particle diameter and a particle size in the above range. The problem can be solved. Therefore, the spherical monodisperse particles may be added in the middle of the polymerization of the polyester resin, or may be included in the polyester film by being added to the finished polyester resin and compounded.

In the polyester film of the present invention, an application layer may be formed on one or both surfaces. The coating layer may be formed on one side or both sides of the polyester film, it can improve the post-processing and blocking properties of the film.

The applicator may include at least one resin selected from the group consisting of polyester resins, acral resins, polyurethane resins, melamine resins, and oxazoline resins, and the coating liquid composition wool comprising the resin. It may be formed by coating on one or both sides of the polyester film and then curing. The coating liquid composition may include a photoinitiator, a solvent, and the like, and the kind thereof is not particularly limited.

Polyester-based resin used in the coating layer is an ester grain in the main chain black side chain It may be a polyester resin having a sum. The glass transition temperature (Tg) of the polyester resin may be 50 ~ 170 ^° C, preferably 50 ~ 150 ^° C. When the Tg is 50 ° C or more, it is possible to exert a proper moisture resistance, and when the Tg is 17CTC or less, the resin is excellent in coating property and the resin can be uniformly applied. The polyester resin may contain a component having a naphthalene and / or fluorene skeleton, or may contain an aromatic dicarboxylic acid component. The polyester resin is the premise is applied to liquid compositions based on the solid content in the range of 0.1 to 50 parts by weight ⁰ / o, preferably from 1 to 30 parts by weight ^_0/0, and more preferably may be used in a 5 to 20% by weight. The acrylic resin used in the coating layer may be a colloidal acrylic-ester copolymer resin. When the coating layer includes an acrylic resin, it may further include an isocyanate, epoxy or melamine-based curing agent for durability and solvent resistance improvement. The acrylic resin may be used in total based on solids in the coating of 0.1 to 60 parts by weight ^_0/0 solution of the composition, preferably 1 to 50 parts by weight ^_0/0, more preferably 10 to 40 wt. ^_0/0. The polyurethane resin used in the coating layer may be prepared by copolymerizing dicarboxylic acid and glycol component. Examples of the dicarboxylic acid component include aromatics such as terephthalic acid, isophthalic acid, 1,4-napralene dicarboxylic acid, 2.5-naphthalene dicarboxylic acid, 2,5-methylcarboxylic acid and dimetal isophthalic acid. Dicarboxylic acid; Alicyclic dicarboxylic acids such as 1,3-cyclopentane dicarboxylic acid, 1,2-cyclonucleic acid dicarboxylic acid, 1,3-cyclohexane dicarboxylic acid, and 1,4-cyclonucleic acid dicarboxylic acid mountain; And aliphatic dicarboxylic acids such as adipic acid, sebacic acid, and the like, with aromatic dicarboxylic acids being particularly preferred. The glykul component is preferably an aliphatic glycol having 2 to 8 carbon atoms and an alicyclic glycol having 6 to 12 carbon atoms, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4 Butanediol, neophenyl glycol, 1,6-hexanediol, 1,2-cyclohexanemethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediethanol, p-xylene glycol, diethylene Glycol, triethylene glycol, polyether glycol, polyethylene glycol, polytetramethylene glycol, and the like, and among these, ethylene glycol is preferable. The polyurethane-based resin may be used as αι to 50 parts by weight ^_0/0, preferably from 1 to 40 parts by weight ^_0/0, more preferably from 5 to 30 parts by weight ^_0/0 based on the solids content of the coating liquid composition premise. The melamine-based resin used in the coating layer may be a melamine-based crosslinking agent, special Although not limited to this, for example, a melylated delamine inducer obtained by condensation of melamine, melaminegoform formaldehyde, a methylolated delamin reaction with a lower alcohol, or a partial black is a completely etherified compound thereof, or Mixtures and the like can be used. Moreover, as a melamine type crosslinking agent, the condensate which consists of a monomer, a dimer or more multimer, black, a mixture thereof, etc. can be used. The tie lamin-based resin may be used in 0.1 to 50% by weight based on the solids content of the coating solution assumes the composition, preferably 1 to 30 parts by weight ^_0/0, more preferably 5 to 20% by weight. The oxazoline-based resin used in the coating layer may be an oxazoline group-containing polymer, and the oxazoline group-containing polymer may include at least one monomer having an oxazoline group, and may be obtained by copolymerization with at least one other monomer. It may be. The oxazoline group-containing polymer may be cured by heat reaction of functional groups such as hydroxyl group and carboxyl group by heat. The oxazoline-based resins to the premise coating liquid composition based on solids in the range of 0.1 to 70 parts by weight ^_0/0, preferably from 1 to 60 parts by weight ^_0/0, more preferably in the can be used in the range of 10 to 50% by weight.

The coating layer may have a thickness of 0.01 to 2 μιτι, preferably 0.01 to 1.5 μηι. When the thickness is in the range of 0.01 / jm to 2 μηι it can exhibit the function of a sufficient coating layer. The coating layer may be formed by an in-line coating method or an offline coating method, and the application of the coating liquid for forming the coating layer may be performed by applying a reverse coater, a gravure coater, a rod coater, an air doctor coater, or other methods. It can be done by wrapping paper. In order to improve the applicability and / or tackiness of the coating liquid for forming the coating layer on the surface of the polyester film on which the coating layer is formed, a chemical treatment or a corona discharge treatment is performed before the coating liquid is applied. Can be made.

In addition, the polyester film of the present invention may include a hard coat layer formed on one side of the film to improve brittleness. The hard coating layer may be made of a resin such as a thermoplastic resin, a thermosetting resin, an ionizing radiation (ultraviolet or electron radiation) curable resin, preferably (a) a bifunctional or higher acrylate monomer having ethylene glycol, and (b Multifunctional Urethane Acrylate-based Oligomer and Multifunctional Acrylate-Based Parenter without Eylene Glycol The hard coating composition including at least one of the monomers may be cured. When the number of functional groups is n, the number of ethylene glycol (EO) contained is n to 2n, and the number average molecular weight is 100 to 200 ^η . It is specified. For example, in the case of a bifunctional acrylate monomer, it may include 2 to 4 ethylene glycol, the number average molecular weight may be 200 to 400. In addition, in the case of a trifunctional acrylate-based monomer, it may include three to six ethylene glycol, the number average molecular weight may be 300 to 600. Preferred examples of the bifunctional or higher acrylate-based monomers include, but are not limited to, the compounds of Table 1 or a mixture thereof.

table

The content of the bifunctional or higher acrylate monomer having ethylene glycol is preferably 50 to 85% by weight, more preferably 60 to 80% by weight ⁰ / ο, based on the solids content of the hard coating composition. Do. The polyfunctional acrylate monomer is a general agent for bifunctional or higher polyfunctional acrylate monomers having no ethylene glycol, preferably at least trifunctional.

Examples of the polyfunctional acrylate monomers include 1,6-hexanediol diacrylate and 1,6-hex Acid Diol Dimethacrylate, Butanediol Diacrylate, Butanediol Dimethacrylate, Tricyclodecane Diacrylate, Cyclonucleic Acid Diacrylate, Tris (2-Hydroxyeryl) Isocyanurate Diac Lallylate, hydroxyl pivalaldehyde modified trimerylolpropane diacrylate, 1,4-butanediol diacrylate, meralic diacrylate, modified metallic diacrylate, acrylate ester, cyclonucleic acid di Methanol Dimethacrylate, 1,4-Butanediol Dimethacrylate, Merallic Dimethacrylate, Trimethylolpropane Triacrylate, Trimetalol Propane Trimethacrylate, Pentaerythritol Triacrylate, Tris ( 2-hydroxyethyl) isocyanurate triacrylate, trifunctional acid ester, trifunctional acrylate ester, trifunctional methacrylate S May be used Le, di Merrill propane tetraacrylate, pentaerythritol tetra-acrylate, penta arc barrels esters, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate and the like. The polyfunctional urethane acrylate-based oligomer is a mixture of bifunctional or higher polyfunctional urethane acrylate oligomers, and includes, for example, all aliphatic or aromatic urethane acrylate oligomers, preferably at least trifunctional and at least tetrafunctional. More preferred. Examples of the polyfunctional urethane acrylate oligomers include bifunctional urethane acrylate oligomers having a number average molecular weight of 1,400 to 25,000, trifunctional urethane acrylate oligomers having a number average molecular weight of 1,700 to 16,000, and tetrafunctional urethane acrates having a number average molecular weight of 1,000. Late oligomers, number average molecular weights 818 to 2,600 I 6 functional urethane acrylate oligomers, 9 functional urethane acrylate oligomers having a number average molecular weight of 3,500 to 5,500, 10 functional urethane acrylate oligomers having a number average molecular weight of 3,200 to 3,900, 15 functional urethane acrylate oligomers having an average molecular weight of 2,300 to 20,000 can be used. The polyfunctional acrylate monomer and / or polyfunctional urethane acrylate oligomer content is preferably 9 to 50% by weight, based on the solid content of the hard coating composition, 15 to 40 weight ⁰ / More preferably. On the other hand, the hard coating composition may include a photoinitiator, a solvent and the like, the type is not particularly limited.

The hard coating layer may have a thickness of about 0.1 μm to about 5 μm, and preferably about 0.5 μm to about 3 μm. μιτι, more preferably 1 to 2 μηι. When the thickness of the hard coat layer is within the preferred rain I, it is advantageous to prevent cracks in the hard coat layer material while preventing cracks or chipping points of the film. In addition, the hardness of the hard coating layer may be H to 5H.

The polyester film of the present invention is prepared by the conventional method of biaxially stretching and heat setting the unstretched sheet in the longitudinal and transverse directions after producing a sheet by melt extruding and engraving the polyester resin of the specific composition. Can be.

Melt extrusion is preferably made at a temperature of Tm + 30 ° C to Tm + 60 ° C of the polyester resin. If the temperature of the extruder during the melt extrusion is less than Tm + 30 ° C, smooth melt does not occur, the viscosity of the extrudate is high, productivity is reduced, on the contrary, in the case of Tm + 60 ° C, depolymerization by thermal decomposition of the resin The molecular weight may drop and problems with oligomers may occur. In addition, the incidence is preferably made at a temperature of 30 ° C or less, more preferably at 15 ° C to 30 ° C.

The polyester film of the present invention may be biaxially stretched in the longitudinal and transverse directions.

In polyester, the defect is mostly due to the decomposition of the polyester chains due to hydrolysis, and particularly the brittleness of the film produced by using the same, even in the length of the jaws, can no longer withstand mechanical deformation such as elongation or bending. . Therefore, as a method for slowing down the decomposition rate, the resistance to the decomposition rate can be greatly increased by providing an orientation to the molecular chain by adjusting the stretching conditions, that is, the stretching rate and the stretching ratio.

In relation to the stretching conditions, in the present invention, biaxial stretching in both the longitudinal direction and the transverse direction is performed, and the stretching temperature is in the range of the glass transition temperature (Tg) ₊ 5 ° C to Tg + 50 ° C of the polyester resin, Preferably it may range from Tg + 10 ° C. to Tg + 40 ^° C. At this time, the lower the better the ductility, but breakage may occur. When the stretching temperature is particularly in the range of Tg + 10 ° C to Tg + 40 ° C, the brittleness of the produced film can be improved. have.

At this time, the draw ratio may be 2 to 5 times, preferably 2.5 to 5 times, more preferably 2.5 to 4.0 times in the longitudinal direction, 2.5 to 5 times in the transverse direction, preferably 3 to 4.5 times, more preferably. Preferably 3.2 to 4.2 times. Preferably, the longitudinal and transverse draw ratios of Class I (MDxTD) may be 4 to 16, preferably 7 to 14, more preferably 8 to 12. Further, the longitudinal drawing speed may be 22 to 500 m / min, preferably 25 to 400 m / min, more preferably 25 to 200 m / min. In this case, when the longitudinal stretching speed is 22 m / min or more, it is advantageous to maintain the desired orientation in the present invention, and since the crystallinity is given according to the longitudinal stretching speed and the stretching ratio, the transverse stretching speed varies depending on the longitudinal stretching conditions.

The film is heat fixed after stretching, the film is relaxed in the longitudinal and / or transverse direction after starting the heat fixing, the heat setting temperature range is preferably 200 ~ 260 ° C.

The polyester film of the present invention prepared as described above may have a thickness of 12 / jm to 400 μηι.

In addition, the polyester film of the present invention may include various additives such as ordinary electrostatic agent, antistatic agent, sunscreen agent, antiblocking agent and other inorganic lubricants within a range that does not impair the effects of the present invention.

Accordingly, the present invention provides an optical film and display paper containing the polyester film.

Hereinafter, the present invention will be described in more detail with reference to a preferred embodiment to aid the understanding of the present invention. However, the following examples are only for illustrating the present invention, and the storm I of the present invention is not limited or limited to the following examples. All.

Remedy A

According to one example, relief, wherein the polyester film has (i) a configuration derived from a diol component comprising at least 90 mole ⁰ / _0. I 1,4- cyclohexyl di methanol danwoo I, and (Π) 3 to 25 mol A polyester resin comprising a structural unit derived from a dicarboxylic acid component containing% isophthalic acid, having a haze of 2% or less, and after 1 hour hold at 15 CTC, the heat shrinkage is reduced in both the longitudinal and transverse directions. It is less than% and the haze change is less than 1%. Such a polyester resin may be induced by polymerization after the ester exchange reaction between the diol component and the dicarboxylic acid component.

The diol component that comprises a constituent unit derived from at least 90 mole ^_0/0, 1,4-cyclohexane dimethanol nucleic acid (CHDM), preferably from the CHDM 98 mole ^_0/0, more preferably ⁰ to 99 mol / _It contains ₀ or more. The diol component may further contain a diol component other than CHDM. Specific examples of the diol component which may be further included as such are ethylene glycol, 1,3-propanediol, 1,2-octanediol, 1,3-octanediol, 2,3-butanediol, 1,3-butanediol , 1,4—butanediol, 1,5-pentanediol, 2,2-dimeryl-1,3-propanediol (neopennylglycol), 2-buryl-2-eryl-1,3-propanediol, 2,2-diethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,1-dimeryl-1,5 -Pentanediol and mixtures thereof. The higher the ratio of CHDM contained in the diol component, the higher the Tg of the polymer, the better the heat resistance and the higher the hydrolysis resistance. However, since the structure of CHDM increases the crystallinity, extrusion or stretching the film for film production Decision calls can occur. Accordingly, the polyester resin contains isophthalic acid as the dicarboxylic acid component in order to lower the crystallization rate. When the isophthalic acid is included, the crystallization rate, which is too high as CHDM is included, can be lowered, and the polymer's melt temperature (Tm) can be lowered to increase the handleability of the polymer, but when included in excess, the Tg of the polymer Gets lower It is possible to lower thermal characteristics such as thermal properties.

In the dicarboxylic acid component is in the isophthaloyl ralsan 3 to 25 mole ^_0/0, relief write down to 5 to 20 mole ^_0/0, the more relief typically 5 to 18 mole ^_0/0, more relief than ever 5 It may contain 15 mol%. The dicarboxylic acid component may comprise terephthalic acid. Relief Generally, the dicarboxylic acid component is the terephthalic acid to 75 to 97 mol%, sphere expulsion of 80 to 95 mole ^_0/0, more relief typically 82 to 95 mole ^_0/0, more relief typically 85 to 95 It may be included in mol%. That is, the polyester resin may be a copolyester resin. In addition, as said dicarboxylic acid component, Aromatic dicarboxylic acid, such as a dimeryl terephthalic acid, a naphthalenedi butyl carboxylic acid, orthophthalic acid; Aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid; Alicyclic dicarboxylic acid; And it may further include one or more selected from the group consisting of these esterified products. Accordingly, the polyester resin may include 1,4-cyclonucleic acid dimerylene isophthalate terephthalate as a main repeating unit. The polyester film has an I intrinsic viscosity (at 25 ° C.) of 0.6 to 1.2 for filming, and it is preferable to have a weight average molecular weight of 30,000 to 50,000 g / m. In addition, the polyester film may include a hard coating layer formed on one side of the film to improve brittleness. The hard coating layer may be made of a resin such as a thermoplastic resin, a thermosetting resin, an ionizing radiation (ultraviolet ray or an electron ray) curable resin, and preferably (a) a bifunctional or higher acrylate monomer having an ethylene glycol (EO). , And (b) a hard coating composition comprising at least one of a polyfunctional urethane acrylate oligomer and a polyfunctional acrylate monomer having no ethylene glycol may be cured. The bifunctional or higher functional acrylate monomer having ethylene glycol is characterized in that when the number of functional groups thereof is n, the number of ethylene glycol contained is n to 2n, and the number average molecular weight is 100η to 200η. . For example, in the case of a bifunctional acrylate monomer, it may include two to four ethylene glycol, and may have a horizontal homogeneous molecular weight of 200 to 400. Also, trifunctional acrylate monomer In this case, it may include 3 to 6 ethylene glycol, the number average molecular weight may be 300 to 600. Preferred examples of the bifunctional or higher acrylate monomer include, but are not limited to, the compounds of Table 1 or mixtures thereof.

Wherein the tolylene bifunctional or more acrylate monomers coming I content with a glycol, and, when based on the solids content of the de-coating composition, and is 50 to 85% by weight, preferably, it is 60 to 80 parts by weight ^_0/0, more preferably . The polyfunctional acrylate monomer is a general agent for bifunctional or higher polyfunctional acrylate monomers having no ethylene glycol, preferably at least trifunctional.

Examples of the polyfunctional acrylate monomers include 1,6-hexanediol diacrylate, 1,6-nucleic acid diol dimethacrylate, butanediol diacrylate, butanediol dimethacrylate, and tricyclodecane diacrylate Latex, cyclohexane diacrylate, tris (2-hydroxyeryl) isocyanurate diacrylate, hydroxyl pivalaldehyde modified trimerylolpropane diacrylate, 1,4-butanediol diacrylate Lateral, Merallic Diacrylate, Modified Meralic Diacrylate, Acrylate Ester, Cyclohexanedi Methanol Dimethacrylate, 1,4-Butanediol Dimethacrylate, Merallic Dimethacrylate, Trimeryl Allpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythrite triacrylate, tris (2—hydroxyether) isocyanurate triacrylate , Trifunctional acid ester, trifunctional acrylate ester, trifunctional methacrylate ester, dimetalol propane tetraacrylate, pentaerythritol tetraacrylate, pentaacrylate ester, dipentaerythritol pentaacrylate, dipenta Hexaacrylate may be used for the erythride. Polyfunctional urethane acrylate oligomers are bifunctional or more _. A general function of the polyfunctional urethane acrylate oligomer is to include all aliphatic or aromatic urethane acrylate oligomers, trifunctional or higher functional is preferable, and tetrafunctional or higher is more preferable. Examples of the polyfunctional urethane acrylate oligomers include bifunctional urethane acrylate oligomers having a number average molecular weight of 1,400 to 25,000, trifunctional urethane acrylate oligomers having a number average molecular weight of 1,700 to 16,000, and tetrafunctional four number molecular weights of 1,000. Urethane acrylate oligomer, 6 functional urethane acrylate oligomer with number average molecular weight 818 to 2,600, I 9 functional urethane arc related oligomer with number average molecular weight 3,500 to 5,500, 10 functional urethane acrylate oligomer with number average molecular weight 15 functional urethane acrylate oligomers having a number average molecular weight of 2,300 to 20,000 may be used. The polyfunctional arc barrels rate-based monomer and / or polyfunctional urethane arc barrels hitting rate based come meoeu i content and the like a hard coating based on solids with 9 to 50% by weight of the composition preferably 15 to 40 parts by weight ^_0/0 More preferably. On the other hand, the hard coating composition may include a photoinitiator, a solvent and the like, the type is not particularly limited.

The thickness of the hard coat layer may be 0.1 to 5 μ (η, preferably 0.5 to 3 μηι, more preferably 1 to 2. When the thickness of the hard coating layer is within the above preferred range, It is advantageous to prevent cracks in the hard coat layer material while preventing cracks or chipping points of the film, and the hardness of the hard coat layer may be H to 5H. Melt extrusion may be performed by a conventional method of melt extruding and engraving a polyester resin of a composition to prepare a sheet, and then biaxially stretching and heat setting the unstretched sheet in the longitudinal and transverse directions. it is preferably Tm + 30 ° C to Tm + 60 ^o C coming from being made in i temperature. the temperature of the melt-extruded upon the extruder this case, seamless melt Tm + 30 ^o C lower than Do not control the extrudate viscosity increases when said fall in productivity, whereas more than Tm + 60 ^o C, the molecular weight of the resin drops to depolymerization by thermal decomposition may cause problems due to the oligomer.

In addition, the nyaenggak is 30 ^o C or less is preferably formed at a temperature of, and takes place in more bar preferably from 15 ° C to 30 ^o C. The polyester film may be biaxially stretched in the longitudinal and transverse directions. At this time, the draw ratio may be 2 to 5 times, preferably 2.5 to 5 times, more preferably 2.5 to 4.0 times in the longitudinal direction, 2.5 to 5 times in the transverse direction, preferably 3 to 4.5 times, more preferably. Preferably 3.2 to 4.2 times. The film is heat fixed after stretching, the film is relaxed in the longitudinal and / or transverse direction after starting the heat fixing, the heat setting temperature range is preferably 200 ~ 260 ^° C. The polyester film thus prepared may have a thickness of 12 ι to 400 μηι.

In addition, the polyester film may include various additives such as a conventional electrostatic agent, an antistatic agent, a sunscreen, an antiblocking agent, and other inorganic lubricants within a range that does not impair the above effects.

Such a polyester film is 3% or less in both the longitudinal direction (length or machine direction, MD) and the transverse direction (width direction, TD) after holding for 30 minutes at 150 ^° C. and further maintaining for 1 hour. In addition, after 30 minutes of maintenance at 15 CTC, the haze change after 1 hour of holding is less than 1%. Preferably, the polyester film may have a heat shrinkage of 1.5% or less in both the longitudinal and transverse directions and a haze law of less than 1% after holding at 150 ^° C. for 1 hour. The polyester film may have a wavelength of 400 to 700 nm. The permeability in can be 90% or more. In addition, the polyester film may be 50% or more to maintain the elongation after 72 hours at 120 ° C and 1.2 atm. The polyester film, such as iodine, is transparent and excellent in heat resistance, and exhibits excellent hydrolysis resistance such as being able to maintain inherent excellent film properties even when exposed to long periods of time, and even at high temperatures and humidity. Since there is no degradation in physical properties, it can be usefully used as an optical film for display.

Hereinafter, more specific examples of the polyester resin preparation according to the above-described control examples are described.

Example A1

100 mol part of 1,4-cyclohexane dimethanol (CHDM) as a diol component, 5 mol part of isophthalic acid and 95 mol part of terephthalic acid as a dicarboxylic acid component were put into the autoclave equipped with a stirrer and a distillation column, and a transesterification catalyst as was input as manganese acetate 0.01 ⁰ / _0. i amount of Te Lev ralsan, it was carried out an ester exchange reaction at 290 ^o C. After completion of the transesterification, Ti to 0.001 ^_0/0-to as a polymerization catalyst It stirred and stirred for 10 minutes. Subsequently, the reaction product was transferred to a second reactor equipped with a vacuum equipment, and then polymerized at 300 ^° C. for 180 minutes to give a poly (1,4-cyclonucleoside di) having an intrinsic viscosity (IV) of 075 and a weight average molecular weight of 35,000. Merylene isophthalate terephthalate) (PCT) copolymer resin was obtained. The PCT resin obtained from 150 ^o C Drying 4 hours, 280 ~ 290 ^o C to obtain a non-stretched sheet and then melt-extruded through an extruder equipped with a screw and brought into close contact with the nyaeng gakreul nyaenggak to 20 ° C at. The pre-stretched sheet was immediately preheated to 60 ° C., and then stretched 2.9 and 3.4 times in the longitudinal and transverse directions at 110 ^° C., respectively, with longitudinal and transverse stretching speeds of 29 m / min and 30 m, respectively. / Min. Subsequently, the stretched sheet was heat-set at 230 ^° C. to prepare a 50-thick copolymer PCT biaxially oriented film. 74 weights each of triethylene glycol diacrylate (SR272, manufactured by Satomer), polyfunctional urethane acrylate oligomer (MU9500, Miwon Specialty Chemicals), and photoinitiator (1-184, BASF) added to the composition 15 parts by weight of 100 parts by weight of ethyl Merrill Kerron containing ^_0/0, 18 weight ^_0/0, and 8% by weight, and stirred to prepare a hard coat composition. The hard coating composition was applied to one side of the PCT biaxially stretched film prepared by the die coating method, and the solvent was dried for about 1 minute by passing through a drying chamber at 70 ^° C., such as a high pressure mercury lamp and a xenon lamp. Ultraviolet rays radiated from the ultraviolet lamp were irradiated with a light amount of 100mJ / cm ² to cure, thereby completing a polyester film having a hard coating layer having a thickness of 2 jum.

Examples A2 to A4

The contents of 1,4-cyclohexanedimethanol (CHDM), isophthalic acid and terephthalic acid were changed as shown in Table 2, respectively, except that the thickness of the hard coat layer was formed as shown in Table 2 below. The same process as in Example A1 was performed to prepare a PCT biaxially oriented film. IV and weight average molecular weight of the prepared PCT resin and the thickness of the prepared film are shown in Table 2.

Comparative Example A1 100 mol parts of erylian glycol and 100 mol parts of terephthalic acid were added to an autoclave equipped with a stirrer and a distillation column, and manganese acetate was used as a transesterification catalyst. After the addition of 0.01% by weight of deoxidation, transesterification was performed at 280 ° C. After the transesterification reaction was completed, 0.01 parts by weight ^_0/0 In the tin oxide as a polymerization catalyst, and stirred for 10 minutes, the hair rente Lev LAL rate (PET) resin was obtained in the IV is 0.61, and a 34,000 weight average molecular weight. The prepared PET resin was dried at 150 ^° C. for 4 hours, melt-extruded through an extruder equipped with a screw at 27 CTC, and then contacted with the angle of 20 ^° C. to obtain an unstretched sheet. The unstretched sheet was immediately preheated to 6 C C and then stretched 2.9 times and 3.4 times in the longitudinal and transverse directions, respectively, at 110 ° C., with longitudinal and transverse stretching speeds of 290 m / min and 300 m /, respectively. It was minutes. Subsequently, the stretched sheet was heat fixed at 230 ^° C. to prepare a PET biaxially stretched film having a thickness of 50 μπι. 74 wt ^. / _0, with 18 added to the composition 15 parts by weight of 100 parts by weight of ethyl Merrill Kerron comprising by weight ^_0/0, and 8% by weight, and stirred to prepare a hard coat composition. The hard coating composition is applied to one surface of the PCT biaxially stretched film by a die coating method, and after passing the drying chamber at 70 ° C. for about 1 minute to dry the solvent, from a UV lamp such as a high pressure mercury lamp or a xenon lamp. Irradiated ultraviolet rays were cured by irradiating with 1,000 mJ / cm ^{2 of} I light quantity to complete a polyester film having a hard coating layer having a thickness of 5 μηη).

Comparative Example A2 100 mol parts of ethylene glycol and 100 mol parts of terephthalic acid were charged into an autoclave equipped with a stirrer and a distillation column, and manganese acetate was added in an amount of 0.01% by weight of terephthalic acid as a transesterification catalyst, followed by 280 °. The transesterification was carried out in C. After the transesterification reaction was completed, the tin oxide αοι weight ^_0/0 added as a polymerization catalyst, and stirred for 10 minutes, and the IV is 0.61 to give the hair terephthalate (PET) resin to the poly 34,000 weight average molecular weight. Subsequently, the reaction product was transferred to a second reaction device equipped with a vacuum facility, and then polymerized at 260 ^° C. for 180 minutes to give a polyylene terephthalate (PET) having an IV of 0.75 and a weight average molecular weight of 45,300. Resin was obtained. Thereafter, using the obtained PET resin, in the same manner as in Comparative Example A1, the film was manufactured by drying, melt extrusion, molding and biaxial stretching to form a hard coating layer on one surface.

Comparative Example A3

Except that 75 mol parts of CHDM was used, a pep resin was prepared in the same manner as in Example 1, and a hard coat layer was formed on two surfaces of I, one surface of which was prepared by drying, melt extrusion, molding, and biaxial stretching. .

Comparative Example A4 Except that no isophthalic acid was used, the per resin was prepared in the same manner as in Example 1, and the film was prepared by drying, melt extrusion, molding, and biaxial stretching. Formed.

For the films prepared in Examples A1 to A3 and Comparative Examples A1 to A4, the heat shrinkage rate, viscosity (IV), permeation, and haze changes are shown together in Table 2 below.

TABLE 2

(150 ° C, 1 hour) Horizontal% 0.8 0.7 0.4 0.3 3.5 1.3 3.5 1.0 Initial haze% 1.1 1.0 1.0 1.1 1.0 0.9 1.2 Initial permeation% 91 91 91 91 89 90 90 Haze after heat treatment

% 1.1 1.0 1.1 1.2 20.3 21.1 10.3 (150 ° C, 1 hr)

Haze change

% 0.0 0.0 0.1 0.1 19.3 20.2 9.1 4.0 (150 ° C, 1 hr)

Permeation after heat treatment% 91 91 91 90 89 90 90

From the results of Table 2, it can be seen that the films of Examples A1 to A4 not only have excellent thermal contraction rate and permeability, but also have very low number of cases of haze. The substrate for heat-resistant optics or the heat-resistant material film should not be eluted with oligomers like the films of Examples A1 to A4, which is advantageous for post processing, optically transparent and oligomers should not be eluted. When the oligomer is eluted at the time of post-processing, since it acts as a foreign material in and and the film reduces production efficiency, a film with little oligomer elution (haze change) is required. For example, a ΠΌ substrate or an ITO protective film or the like undergoes heat preservation during processing for ITO crystallization, and thus oligomers are generated on the surface of a general PET film. The film of Comparative Example A1 is a general optical PET film, and the film of Comparative Example A2 solidifies the polyester resin prepared in Comparative Example A1 to raise Tg and Tm to improve heat resistance. However, the films of Comparative Examples A1 and A2 were relatively large in the number of haze P ᅡ, indicating that a large amount of oligomer elution occurred at high temperature. Specifically, the oligomer elutes to the film surface after the heat resistance test in the oven, thereby raising the haze. The film surface at this time

White oligomers are collected when rubbed with a spatter. In the present specification, the resin of the oligomer elution can be confirmed by haze. Comparative Example A3 of the film CHDM content of a 80 mole lower than _{^0/0, and} lowers the Tg because of the CHDM content that affect the crystallization, column weakened resistance, as well as a large heat shrinkage, the change in the haze degree relative of You can see the big picture. In addition, when using CHDM as the diol component and only TPA without IPA as the dicarboxylic acid component, as in Comparative Example A4, the crystallization rate is very fast due to crystallization during melt extrusion. This leads to a state in which the film cannot be formed.

Remedy B

According to a further relief example, the polyester film has a constituent unit derived from a diol component comprising hexane dimethanol (i) at least 90 mol% 1,4-cyclohexane, and (ii) on the Te Lev 90 mole ^_0/0 Polyester resin comprising a structural unit derived from a dicarboxylic acid component containing lactic acid, the heat shrinkage after holding for 30 minutes at 150 ^o C is less than or equal to 3% in both the longitudinal and transverse directions, 120 ° C. And elongation retention after 72 hours at 1.2 atm is more than 50%. Such a polyester resin may be induced by polymerization after the ester exchange reaction between the diol component and the dicarboxylic acid component.

The diol component comprises structural units derived from 90 mole ^_0/0 or more 1,4-cyclohexanedimethanol (CHDM), preferably CHDM to 98 mole ^_0/0, more preferably at least 99 mol% Include. The diol component may further contain a diol component other than CHDM. Specific examples of the diol component which may be further included as such are ethylene glycol, 1,3-propanediol, 1,2-octanediol, 1,3-octanediol, 2,3-butanediol, 1,3- Butanediol, 1,4-butanediol, 1,5—pentanediol, 2,2-dimeryl-1,3-propanediol (neopentylglycol), 2-butyl-2-ethyl-1,3-propanediol , 2,2-diaryl-1,5-pentanediol, 2,4-diethal-1,5-pentanediol, 3-metal-1,5-pentanediol, 1,1-dimeryl-1, 5-pentanediol and mixtures thereof are mentioned. When the isopral acid is included, the crystallization rate, which is too high as CHDM is included, may be lowered, and the polymer meltability may be lowered by lowering the melting temperature (Tm) of the polymer, but when included in an excessive amount, The Tg may be lowered to lower thermal characteristics such as heat resistance. In the dicarboxylic acid component may include The isophthaloyl ralsan to less than 10 mol ^_0/0.

In addition, as said dicarboxylic acid component, Aromatic dicarboxylic acid, such as dimethyl terephthalic acid, naphthalenedicarboxylic acid, orthophthalic acid; Adipic acid, azela mountain, sebacic acid, Aliphatic dicarboxylic acids such as decanedicarboxylic acid; Alicyclic dicarboxylic acid; And it may further include one or more selected from the group consisting of these esterified products. Accordingly, the polyester resin may include 1,4—cyclonucleic acid dimethyllian terephthalate as the main repeating unit. The polyester film has an intrinsic viscosity (at 25 ⁰ C) of 0.6 to 1.2 for filming, and preferably has a weight average molecular weight of 30,000 to 50,000 g / mol, especially 30,000 to 40,000 g / m.

The polyester film is a polyester resin comprising a dicarboxylic acid component and a diol component comprising at least 90 mol% to 90 mol Pohang ^_0/0 or more nucleic acid 1,4-cyclohexane dimethanol terephthalic and melt extrusion nyaenggak After the sheet is prepared, the sheet may be produced by a method including biaxially stretching and heat setting the sheet in the longitudinal and transverse directions. The melt-extrusion is preferably be a luer at the temperature of the polyester to build Tm + 30 ° C to I Tm + 60 ^o C. When the temperature of the extruder during the melt extrusion is less than Tm + 30 ^o C, the smooth melt does not occur, the viscosity of the extrudate is high, productivity is reduced, on the contrary, in the case of Tm + 60 ^o C, depolymerization by thermal decomposition The molecular weight of is lowered and problems may occur due to the oligomer. In addition, the angle is preferably made at a temperature of 30 ^° C or less, more preferably from 15 ⁰ C to 30 ^° C. In polyester, the defect is mostly due to the decomposition of the polyester chains due to hydrolysis, especially the minimum grip length of the film produced by using it, which is no longer able to withstand mechanical deformation such as elongation or bending. . Therefore, as a method for slowing down the decomposition rate, the resistance to the decomposition rate can be greatly increased by providing the orientation to the molecular procedure by adjusting the stretching conditions, that is, the stretching rate and the stretching ratio. Stretching conditions and with respect to a longitudinal and is performed is biaxially stretched in both the transverse direction, the stretching-on to turn the glass transition temperature of the polyester resin (Tg) + the range of 5 ° C to Tg + 50 ^o C, preferably from Tg It may range from + 10 ° C to Tg + 40 ° C. At this time, the lower the Tg, the better the ductility, but breakage may occur. In particular, when the stretching temperature is in the range of Tg + 10 ° C. to Tg + 40 ° C., the brittleness of the produced film can be improved. Preferably, the product of longitudinal and transverse draw ratios (MDxTD) may be 4 to 16, preferably 7 to 14, more preferably 8 to 12. Further, the longitudinal drawing speed may be 22 to 500 m / min, preferably 25 to 400 m / min. In this case, when the longitudinal stretching speed is 22 m / min or more, it is advantageous to maintain the desired orientation, and since the crystallinity is given according to the longitudinal stretching speed and the stretching ratio, the transverse stretching speed varies depending on the longitudinal stretching conditions. The film is heat fixed after stretching, the film is relaxed in the longitudinal and / or transverse direction after starting the heat fixing, the heat setting temperature range is preferably 200 ~ 260 ^° C. The polyester film prepared as described above may have a thickness of 12 / jm to 400 μιτι. In addition, the polyester film may include various additives such as a conventional electrostatic agent, an antistatic agent, a sunscreen, an antiblocking agent, and other inorganic lubricants within a range that does not impair the above effects. In electrical insulation applications or films for solar cell module backside laminates, a relatively long durability of up to several years is required under the application temperature of about 78 ⁰ C, the vitrification temperature range of polyester polyylene terephthalate (PET). do. Under these conditions, the tendency of hydrolysis of the polyester is very important for durability in the application. The polyester film had a heat shrinkage ratio of 3% or less in both the longitudinal direction (length or machine direction, MD) and transverse direction (width direction, TD) after 30 minutes at 15 CTC, and 72 hours at 120 ^° C. and 1.2 atm. After elongation retention is more than 50%. In addition, the polyester film may have a transmittance of 88% or more at a wavelength of 400 to 700 nm, and an intrinsic viscosity (IV) retention after 72 hours at 120 ° C. and 1.2 atm may be 70% or more. Polyester films such as IOS have excellent hydrolysis resistance, such as transparency and long term, and even excellent exposure to high temperature and humidity, and excellent hydrolysis resistance. Under the circumstances, it can be usefully used as a film for solar, electric insulation and retort packaging. Hereinafter, more specific examples of the polyester resin preparation according to the above-described control examples are described.

Example B1

100 mol parts of 1,4-cyclohexamethanol (CHDM) and 100 mol parts of terephthalic acid were added to an autoclave equipped with a stirrer and a distillation column, and manganese acetate was added in an amount of 0.1% by weight of terephthalic acid as a transesterification reaction group. Then, transesterification was carried out at 29 CTC. After completion of ester exchange reaction, 0.001 ^_0/0 In the Τί as a polymerization catalyst, and the mixture was stirred for 10 minutes. Subsequently, the reaction product was transferred to a second reactor equipped with a vacuum equipment, and then polymerized at 300 ^° C. for 180 minutes to give a poly (1,4-cyclohexanedimerylene te) having an IV of 0.80 and a weight average molecular weight of 35,000. Leprolatate) (PCT) resin was obtained. The prepared PCT resin was melt-extruded through an extruder at 280 ^° C., and then adhered to the angle of angle at 20 ° C. to obtain an unstretched sheet. The sheet thus obtained was immediately preheated to 60 ^° C. and then stretched 2.9 times and 3.4 times in the longitudinal and transverse directions at 110 ° C., respectively, where the longitudinal and transverse stretching speeds were 29 m / min and 28 m / min. Subsequently, the stretched sheet was heat-set at 240 ° C. to prepare a PCT biaxially stretched film having a thickness of 50 μηι.

Example Β2

While using a PCT resin prepared in a similar manner to Example B1, the same as Example B1, except that the longitudinal and transverse draw ratios and the longitudinal draw speeds were varied as described in Table 3 below. The process was performed to produce a PCT biaxially oriented film.

After Comparative Example B1 In a teolren glycol 100 molar parts, and Te Lev ralsan 100 mole parts of an autoclave with a stirrer and distillation attachment, and a transesterification chukmae added manganese acetate in an amount of from 0.001 ^_0/0 of Te Lev deoxidizing Transesterification at 280 It was. After completion of the transesterification banong, 0.01 ^_0/0 0 In the Sb as a polymerization catalyst, and the mixture was stirred for 10 minutes. Subsequently, the reaction product was transferred to a second reaction tank equipped with a vacuum equipment, and then polymerized at 260 ° C. for 180 minutes to obtain a polyethylene terephthalate (PET) resin having IV group 0 and a weight average molecular weight of 34,000. It was. The PET resin was melt-extruded through an extruder at 265 ⁰ C, and then adhered to the angle of angle at 20 ° C. to obtain an unstretched sheet. The sheet thus obtained was immediately preheated to 60 ^° C., and then 110 ° C. longitudinal direction and the number of rows were respectively 3.4 times and 4.0 times stretched in the transverse direction at, the ^[for all the longitudinal and transverse stretching been velocity are each 34 m / min and 33 m / min. Subsequently, the stretched sheet was heat-set at 220 ^° C. to produce a PET biaxially stretched film having a thickness of 125 τ.

Comparative Example B2

While using a PET resin prepared in a similar manner to Comparative Example B1, the same as in Comparative Example B1 except for changing the longitudinal and transverse draw ratios and the longitudinal draw speed as shown in Table 3 below. The process was carried out to produce a PET biaxially stretched film.

Heat shrinkage rate, IV, mechanical properties (tensile strength and elongation at break), permeation and IV after autoclave treatment for the films prepared in Examples B1 to B3 and Comparative Examples B1 to B4. And measured by the change in mechanical properties are shown in Table 3 below.

table

Immediately after manufacture sheet IV value 0.62 0.66 0.67 0.71 0.69 0.66 0.67

o o o t 2.5 1.2 1.1 1.2 / 0.7 1.5 0.8

%

(150 ° C, 30 minutes)

c> 1 Hi:

o o 0.9 0.3 -0.1 0 0.1 0

ooo 15 15 13 18 23 11 Tensile Strength kgf / mm ²

number

o 1 ^■ lower:

o o 17 18 19 23 27 13 o o o: 98 106 87 170 120 100 Elongation at break%

number

o 1:

o o 61 64 51 100 100 72 autoclave tension joba

oo σ 13.5 11 11.5 9 19 5.6 kgf / mm ²

Rave Robbery Arc

ο 1: Hi:

ο ο 15.1 17 13 9.66 18 6.5

Breaking ο ο ο 59 69 54 68 22 37

%

(72 hr) Stretch ο ο 40 54 32 8 25 29 Autoclave IV dl / gr 0.59 0.59 0.59 0.23 0.38 0.30 Rave IV maintenance

o ^" (initial IV / autocle% 95 89 88 32 55 45

(72hr) Eve after IV)

Other Breaking Debt Consolidation% 90 91 90.9 91 88

From the results in Table 3, it can be seen that the films of Examples B1 to B3 exhibit not only excellent heat shrinkage and permeability but also high IV retention and high elongation retention even after autoclave disengagement. On the other hand, the film of Comparative Examples B1 and B2 using PET resin and the film of Comparative Example 4, in which the drawing speed is out of the preferred range, have a sharp decrease in IV value and elongation value after autoclave treatment at high temperature and high pressure. In the case of Comparative Example B3, which deviates from the preferred range, breakage occurred during the manufacturing process.

Remedy C

According to yet another embodiment, the polyester film has (i) 1,4- cyclohexanedimethanol methanol structural units derived from a diol component containing 90 mol ^_0/0 or more, and (ii) terephthalic acid 80 mol ⁰ / Structural unit derived from a dicarboxylic acid component containing ₀ or more Including a polyester resin containing, the vitrification temperature of the polyester resin is 88 ° C. or more, after maintaining at 150 ° C. for 30 minutes, heat shrinkage is less than or equal to 3% in both the longitudinal and transverse directions, on one side or both sides An application layer is formed. The polyester resin, such as iodine, may be derived by polymerizing an ester exchange reaction between the diol component and the dicarboxylic acid component.

The diol component is 90 mol ^_0/0 over lead i 1,4-cyclohexanedimethanol and Pohang a constituent unit derived from methanol (CHDM), preferably CHDM to 98 mole ^_0/0, more preferably at least 99 mole It comprises ^_0/0 above. The diol component may further include a diol component other than CHDM. Specific examples of such diol components that may be further included include ethylene glycol, 1,3-propanediol, 1,2-octanediol, 1,3-octanediol, 2,3-butanediol, 1,3-butanediol, 1,4—butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopennylglycol), 2-buty-2-eryl-1,3-propanediol, 2, 2-diethyl—1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 3-methyl-1,5—pentanediol, 1,1-dimeryl-1,5-pentane Diols and mixtures thereof. The dicarboxylic acid component comprise the terephthalic acid to 80% or more by mole, preferably 80 mole ^_0/0 or more and less than 100 mole ^_0/0, more preferably 90 mol ^_0/0 100 mol is less than ^_0/0 Can be.

The higher the ratio of CHDM contained in the diol component, the higher the Tg of the polymer, the better the heat resistance and the higher the hydrolysis resistance. Determination can occur when drawing. Accordingly, the polyester resin may include isophthalic acid in addition to terephthalic acid as the dicarboxylic acid component in order to lower the crystallization rate.

When the isophthalic acid is included, it is possible to lower the crystallization rate, which is too high as CHDM is included, and to increase the polymer agility by lowering the melting temperature (Tm) of the polymer. The Tg may be lowered to lower thermal characteristics such as heat resistance.

In the dicarboxylic acid component is less than the isophthaloyl ralsan 10 mol%, preferably 0 mole ^_0/0 larger than 7 mole ^_0/0 or less, more preferably 0 mole ^_0/0 is more than 5 mole ^_0/0 May include. In addition, as said dicarboxylic acid component, aromatic dicarboxylic acid, such as dimethyl terephthalic acid, naphthalenedicarboxylic acid, orthophthalic acid; Aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid; Alicyclic dicarboxylic acid; And it may further include one or more selected from the group consisting of these esterified products. Accordingly, the polyester resin used may include 1,4-cyclohexane dimethylene terephthalate as the main repeating unit.

The polyester film is 0.6 ~ 1.2 £ | for filming. It has an intrinsic viscosity (at 25 ° C) and preferably has a weight average molecular weight of 30,000 to 50,000 g / m. The polyester film may have a coating layer formed on one side or both sides. The coating layer may be formed on one or both sides of the polyester film, it is possible to improve the post-processing and blocking properties of the film.

The coating layer may include one or more resins selected from the group consisting of polyester resins, acral resins, polyurethane resins, delamine resins and oxazoline resins, wherein the coating liquid composition comprising the resin is It may be formed by coating on one or both sides of the polyester film and then curing. The coating liquid composition may include a photoinitiator, a solvent, and the like, and the kind thereof is not particularly limited.

The polyester resin used in the coating layer may be a polyester resin having an ester bond in the main chain black side chain. The glass transition temperature (Tg) of the polyester resin may be 50 ~ 170 ^° C, preferably 50 ~ 150 ^° C. When the Tg is 50 ° C or more, it is possible to exert an appropriate moisture-resistant adhesive strength, and when the Tg is 17CTC or less, the resin is excellent in coatability and the resin may be uniformly applied. The polyester resin may contain a component having a naphthalene and / or fluorene skeleton, or may contain an aromatic dicarboxylic acid component. The replicon ester resin may be a full coating liquid based on a range of 0.1 to 50 parts by weight ^_0/0 on the solids content of the composition, preferably 1 to 30 parts by weight ^_0/0, more preferably 5 to 20% by weight. The acral resin used in the coating layer may be a colloidal acrylic-ester copolymer resin. When the coating layer includes an acrylic resin, it may further include an isocyanate, epoxy or delamine-based curing agent for improving durability and solvent resistance. The acrylic resin is based on the solid content of the entire coating liquid composition As may be αι to 60 parts by weight ^_0/0, preferably from 1 to 50 parts by weight ^_0/0, and more preferably 10 to 40 parts by weight ^_0/0. The polyurethane resin used in the coating layer may be prepared by copolymerizing dicarboxylic acid and glycol component. Examples of the dicarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 1,4-naphthalene dicarboxylic acid, 2.5-naphthalene dicarboxylic acid, 2,5-merylcarboxylic acid, and dimerylisophthalic acid. Carboxylic acid; Alicyclic dicarboxylic acids such as 1,3-cyclopentane dicarboxylic acid, 1,2-cyclonucleic acid dicarboxylic acid, 1,3-cyclonucleic acid dicarboxylic acid, and 1,4—cyclohexane dicarboxylic acid mountain; And aliphatic dicarboxylic acids such as adipic acid, sebacic acid, and the like, with aromatic dicarboxylic acids being particularly preferred. The glycol component is preferably aliphatic glycols having 2 to 8 carbon atoms and cycloaliphatic glycols having 6 to 12 carbon atoms, for example, ylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4 -Butanediol, neopentyl glycol, 1,6-hexanediol, 1,2-cyclonucleic acid methanol, 1,3-cyclonucleic acid dimethanol, 1,4-cyclohexanedimethanol, Ρ-xyllian glycol, dierylene Glycols, triethylene glycol, polyether glycols, polyylene glycols, and polytetramethylene glycols, and the like, of which ethylene glycol is preferred. The polyurethane resin is the premise of the coating liquid composition based on the solids content of 0.1 to 50 parts by weight ^_0/0, preferably from 1 to 40 parts by weight to ^_0/0, and more preferably may be used in 5 to 30% by weight. The melamine-based resin used in the coating layer may be a melamine-based crosslinking agent, but is not particularly limited, for example, methylolhotel melamine inducer obtained by condensation of queramine, delamingo ᅡ formaldehyde, and melylated delamin. The partial alcohol is reacted with a lower alcohol to a partially etherified compound, or a mixture thereof. In addition, as a delamine type crosslinking agent, the condensate which consists of a monomer, a dimer or more multimer, black, a mixture thereof, etc. can be used. The tie lamin-based resin may be used based on the assumption applied in the range of 0.1 to 50 parts by weight ^_0/0 on the solids content of the liquid composition, preferably 1 to 30 parts by weight ^_0/0, more preferably 5 to 20% by weight. The oxazoline-based resin used in the coating layer may be an oxazoline group-containing polymer, and the oxazoline group-containing polymer may include at least one monomer having an oxazoline group, and may be copolymerized with at least one other monomer. It may be obtained. An oxazoline group containing polymer hardens | cures by heating functional group addition reactions, such as a hydroxyl group and a carboxyl group, by heat. The oxazoline-based resin of the whole coating liquid composition Based on the solids content of 0.1 to 70 parts by weight ^_0/0, preferably from 1 to 60 parts by weight ^_0/0, and more preferably may be used in 10 to 50 parts by weight ⁰ / o. The coating layer may have a thickness of 0.01 to 2 μ (η, preferably 0.01 to 1.5 μιι. When the thickness is in the range of 0.01 μη ⁾ to 2 ^, a sufficient coating layer may function. The coating layer may be formed by an in-line coating method or an offline coating method, and coating with a coating liquid for forming the coating layer may include a reverse coater, a gravure coater, a rod coater, an air doctor coater, or the like. Either can be done by wrapping paper.

In order to improve the applicability and / or adhesion of the coating liquid for forming the coating layer on the surface of the polyester film on which the coating layer is formed, a chemical treatment or a corona discharge treatment is performed before the coating liquid is applied. Can be done. In addition, the polyester film may include a hard coating layer formed on one side of the film to improve brittleness. The hard coating layer may be made of a resin such as a thermoplastic resin, a thermosetting resin, an ionizing radiation (ultraviolet ray or an electron ray) curable resin, preferably (a) a bifunctional or higher acrylate monomer having an ethylene glycol (EO), And (b) a hard coating composition including at least one of a polyfunctional urethane acrylate oligomer and a polyfunctional acrylate monomer having no ethylene glycol. The bifunctional or higher functional acrylate monomer having an ethylene glycol is characterized in that when the number of functional groups thereof is n, the number of ethyl lylene glycol included is n to 2 n, and the number average molecular weight is 100 to 200 η. do. For example, in the case of a bifunctional acrylate monomer, it may include two to four ethylene glycol, and may have a horizontal equivalent molecular weight of 200 to 400. In addition, when the trifunctional I acrylate-based monomer, it may include 3 to 6 ethylene glycol, the number average molecular weight may be 300 to 600. Preferable examples of the bifunctional or higher I acrylate monomer include the compounds of Table 1 or mixtures thereof, but are not limited thereto.

The content of the bifunctional or more acrylate-based monomer having a tolylene glycol in the are, and when based on the solids content of the de-coating composition, 50 to 85 parts by weight ⁰ /. Is preferred, and 60 to 80 parts by weight ^_0/0, more preferably Do. The polyfunctional acrylate monomer is a general agent for bifunctional or higher polyfunctional monomers having no ethylene glycol.

Examples of the polyfunctional acrylate monomers include 1,6-hexanediol diacrylate, 1,6-nucleic acid diol dimethacrylate, butanediol diacrylate, butanediol dimethacrylate, tricyclodecane diacrylate , Cyclonucleic acid diacrylate, tris (2-hydroxyaryl) isocyanurate diacrylate, hydroxyl pivalaldehyde modified triarylolpropane diacrylate, 1,4-butanediol diacrylate, merallic Diacrylates, Modified Metallic Dicrates, Acrylate Esters, Cyclohexanedi-Methanol Dimethacrylate, 1,4-Butanedi-Dimethacrylate, Metallic Dimethacrylate, Trimethylolpropane Triacryl Latex, trimerylolpropane trimethacrylate, pentaerythritol triacrylate, tris (2-hydroxyeryryl) isocyanurate triacrylate , Trifunctional acid ester, trifunctional acrylate ester, trifunctional methacrylate ester, dimerol propane tetraacrylate, pentaerythritol tetraacrylate, pentaacrylate ester, pentaacrylate, pentaacrylate, Hexaacrylate etc. can be used for dipentaerythrine. The polyfunctional urethane acrylate-based oligomer is a mixture of two or more polyfunctional urethane acrylate oligomers, and includes, for example, both aliphatic or aromatic urethane acrylate oligomers, preferably at least trifunctional and tetrafunctional. The above is more preferable. Examples of the polyfunctional urethane acrylate-based oligomer include bifunctional urethane acrylate oligomers having a number average molecular weight of 1,400 to 25,000, trifunctional urethane acrylate oligomers having a number average molecular weight of 1,700 to 16,000, and a number average molecular weight of 1,000 I 4-functional urethane acrylate. Oligomers, 6 functional urethane acrylate oligomers having a number average molecular weight of 818 to 2,600, 9 functional urethane acrylate oligomers having a number average molecular weight of 3,500 to 5,500, 10 functional urethane acrylate oligomers having a number average molecular weight of 3,200 to 3,900, number average molecular weight 2,300 to 20,000 15 functional urethane acrylate oligomer and the like can be used. The polyfunctional arc barrels rate-based monomer and / or polyfunctional urethane content of bots hitting the acrylate-based is, and this would of 9 to 50 parts by weight ^_0/0 based on the solids content of the hard coating composition preferably, 15 to 40 parts by weight ⁰ / It is more preferable that it is _zero . On the other hand, the hard coating composition may include a photoinitiator, a solvent and the like, the type is not particularly limited.

The hard coating layer may have a thickness of 0.1 to 5, preferably 0.5 to 3, and more preferably 1 to 2 /. When the thickness of the hard coat layer is within the preferred rain I, it is advantageous to prevent cracks in the hard coat layer material while preventing cracks or chipping points of the film. In addition, the hardness of the hard coating layer may be H to 5H. The polyester film may be one containing fine particles in a polyester resin. When foaming the fine particles, the running and blocking resistance of the polyester film can be improved. The fine particles may be, for example, inorganic particles such as colloidal silica, titanium oxide, alumina oxide, zirconium oxide or calcium carbonate, or organic particles such as crosslinked polyester particles, crosslinked polystyrene particles, or crosslinked polymer particles. , 1 type may be used, or 2 or more types may be used together. The polyester film may be prepared by a conventional method of biaxially stretching and heat setting the unstretched sheet in the longitudinal and transverse directions after the sheet is prepared by melt extruding and engraving the polyester resin of the specific composition. Can be. Melt extrusion is preferably performed at a temperature of I Tm + 30 ^o C to Tm + 60 ^o C with a polyester resin. If the temperature of the extruder during the melt extrusion is less than Tm + 30 ° C, the smooth melt does not occur, the viscosity of the extrudate is high, productivity is reduced, on the contrary, if the temperature exceeds Tm + 60 ^o C, depolymerization by thermal decomposition of the resin The molecular weight may drop and problems with oligomers may occur. In addition, the incidence is preferably made at a temperature of 30 ° C or less, more preferably at 15 ⁰ C to 30 ° C. The polyester film may be biaxially stretched in the longitudinal and transverse directions. At this time, the draw ratio may be 2 to 5 times, preferably 2.5 to 5 times, more preferably 2.5 to 4.0 times in the longitudinal direction, 2.5 to 5 times in the transverse direction, preferably 3 to 4.5 times, more preferably. Preferably 3.2 to 4.2 times. The film is heat fixed after stretching, the film is relaxed in the longitudinal and / or transverse direction after starting the heat fixing, the heat setting temperature range is preferably 200 ~ 260 ^° C. The polyester film thus prepared may have a thickness of 12jum to 400μιτι.

In addition, the polyester film may include various additives such as a conventional electrostatic agent, an antistatic agent, a sunscreen, an antiblocking agent, and other inorganic lubricants within a range that does not impair the above effects. Such a polyester film may have a static friction coefficient and a dynamic friction coefficient of 0.8 or less, respectively, preferably 0.1 to 0.7. As such, the polyester film may be easily wound in a * state because the static friction coefficient and the equivalence coefficient are each 8 or less.

In addition, the polyester film is maintained at 150 ° C. for 30 minutes, the heat shrinkage is less than or equal to 3% in both the longitudinal (length or machine direction, MD) and transverse (width, TD), and also 30 minutes at 150 ^o C The haze change after holding is 1% or less, preferably 0.6% or less, and the total light transmission may be 90% or more. The polyester film is transparent and excellent in heat resistance, and exhibits excellent hydrolysis resistance such as being able to maintain inherent excellent film properties even when exposed to long periods of time and even at high temperature and high humidity. Since there is no deterioration of the cryogenicity and less oligomer elution, it can be usefully used as an optical film for display.

In addition, since the coating layer is formed on at least one surface of the polyester film, it has an excellent post workability due to excellent cohesion with functional layers that can be further laminated to the film.

Hereinafter, examples of the preparation of the polyester resin according to the above-described control example are described.

Example C1

90 mole parts of 1,4-cyclohexanedimethanol (CHDM), 10 mole parts of dielylene glycol, 90 mole parts of terephthalic acid and 10 mole parts of isophthalic acid were added to an autoclave equipped with a stirrer and a distillation column, and manganese acetate was used as a transesterification catalyst. After input in an amount of αοι weight% of leproic acid, transesterification was carried out at 290 ° C. Este After completion of the reaction exchange LE, 0.001 ^_0/0 In the Ti as a polymerization catalyst, and the mixture was stirred for 10 minutes. Subsequently, the reaction mixture was transferred to a second reactor equipped with a vacuum equipment, and then polymerized at 300 ^° C. for 180 minutes to give a poly (1,4-cyclohexane) having an IV (high viscosity) of 075 and a weight average molecular weight of 35,000. Dimerylene terephthalate) (PCT) resin was obtained.

The prepared PCT resin was dried at 150 ^° C. for 4 hours, melt-extruded through an extruder equipped with a screw at 280-290 ° C., and then contacted with the angle of angle of 20 ° C. to obtain an unstretched sheet. The sheet thus obtained was immediately preheated to 60 ° C. and then stretched three times in the longitudinal and transverse directions at 110 ^° C., respectively, with longitudinal and transverse stretching speeds of 29 m / min and 30 m / min, respectively. Subsequently, the stretched sheet was heat-set at 230 ° C. to prepare a PCT biaxially stretched film having a thickness of 50 1. Based on solids, to the tree as arc reolgye resin teolren glycol diacrylate (SR272, Sartomer Co., Ltd.) 30 parts by weight ^_0/0, the aqueous polyester binder (a refraction 1.54) as the polyester resin 10 parts by weight ^_0/0, urethane polyurethane resin (heptane schemes use, as a resin HWU- 1123A: the polyether polyurethane of the anion group-containing hydroxy-functional urethane acrylate oligomer tan (MU9500, Miwon Spanish seolti Chemical Co.) 20 parts by weight ^_0/0, and oxazoline resin (epoch Ross WS-500, Nippon show kubayi Co., Ltd.) 40 parts by weight ^_0/0 methyl mixed resin of 100 parts by weight made up by adding to 30 parts by weight of the hair Kerron then photoinitiator here il ^¬ ls ^ BASF Co.) 0.01 Part by weight was added and stirred to prepare a coating liquid composition. The additive coating liquid composition was applied on the PCT biaxially stretched film prepared by the die coating method, and the solvent was dried for about 1 minute by passing through a 70 ^° C. drying chamber, followed by ultraviolet lamps such as a high pressure mercury lamp and a xenon lamp. Ultraviolet rays radiated from the surface were cured by irradiating with 1,000 mJ / cm ² light quantity, thereby completing a polyester film in which a coating layer having a thickness of 2 μι was formed.

Example C2 and C3 As the diol component, 100 mol parts of 1,4-cyclonucleic acid dimethanol (CHDM), 97 mol parts of terephthalic acid, and 3 mol parts of isophthalic acid were used, and the coating liquid composition was shown in Table 4, respectively. A PCT biaxially oriented film was prepared in the same manner as in Example C1, except that the coating layer was formed by using a composition and a content thereof. Comparative Example 100 mol parts of CI ethylene glycol and 100 mol parts of terephthalic acid were added to an autoclave equipped with a stirrer-operation distillation column, and manganese acetate was added in an amount of 0.01% by weight of terephthalic acid as a transesterification catalyst, followed by 28CTC. The transesterification reaction was carried out. After the transesterification reaction was completed, the tin oxide is 0.01 ^{_0/0-to-mouth} as a polymerization catalyst, and the mixture was stirred for 10 minutes. A polyaryl lenterephthalate (PET) resin with an IV of 0.61 and a weight average molecular weight of 34,000 was obtained. The prepared PET resin was dried at 150 ^° C. for 4 hours, melt-extruded through an extruder equipped with a screw at 270 ° C., and then adhered to a roll roll angled at 20 ° C. to obtain an unstretched sheet. The sheet thus obtained was immediately preheated to 60 ^° C., and then stretched three times in the longitudinal and transverse directions at 110 ° C., respectively, with longitudinal and transverse stretching speeds of 290 m / min and 300 m / min, respectively. . Then, the stretched sheet was heat-set at 230 ° C to prepare a PET biaxially stretched film having a thickness of 50 μιη.

Comparative Example C2

30% by weight of triethylene glycol diacrylate (SR272, manufactured by Satomer) as an acral resin, 20% by weight of an aqueous polyester binder (refractive 1.54) as a polyester-based resin, polyurethane resin as a urethane-based resin (hep four schemes, HWU-1123A: the hydroxyl polyether polyurethane of the anion containing the lock when hitting all functional urethane acrylate Murray (MU9500, Miwon Specialty Chemicals, Inc.) 10 parts by weight ^_0/0, oxazoline-based resin (epoch Los WS- 500, a Nippon shows a kubayi Co., Ltd.) was added Rilke Walloon I to 40 parts by weight ^_0/0, and then the methyl (in the above each component by weight ⁰ / ᄋ is based on solids of composition premise), a photoinitiator (1-184, BASF Co.) The methyl arylkeron and the photoinitiator were used in amounts of 30 parts by weight and 0.01 parts by weight, respectively, when the total amount of the resins was 100 parts by weight. The coated liquid composition was applied by a die coating method on the PET biaxially stretched film obtained by the method described in Comparative Example C1, and passed through a drying chamber at 70 ° C. for about 1 minute to dry the solvent, followed by a high pressure mercury lamp and xenon Irradiate ultraviolet rays emitted from ultraviolet lamps such as lamps at 1,000 mJ / cm ² I light quantity and stabilize them. The polyester film in which the coating layer of thickness was formed was completed.

Comparative Example C3

As in Example C1, except that 75 mol parts of CHDM and 25 mol parts of diethyl lynchol were used, and the coating liquid composition was prepared in the composition and content as shown in Table 4 below to form a coating layer. PCT biaxially oriented film was prepared by performing the process of.

Heat shrinkage of the films prepared in Examples C1 to C3 and Comparative Examples C1 to C3 was measured together with haze, coefficient of friction, and adhesion after 30 minutes of holding at initial haze and 15 CTC.

Table 4

(150 ° (： at

O o · o% 1.8 0.8 0.5 1.1 0.9 2.5 after 30 min hold)

Initial Haze% 0.56 0.48 0.45 0.89 0.7 0.89

30 minutes at 150 ° C

% 0.83 0.58 0.55 25 15 10 Haze after hold

0.62 / 0.5 / 0.5 / Cjizer

o 0.5 / 0.6 / coefficient of friction dynamic friction / polishing

0.3 0.2 0.3 No 0.2 0.3 ᄌ 大大 서 o o o Bad Good Good

From the results of Table 4, it can be seen that the films of Examples C1 to C3 not only have excellent thermal contraction rate and permeability, but also have very low number of cases of haze. The substrate for heat-resistant optics or the heat-resistant material film is advantageous for post-processing and is optically transparent as long as the oligomer is not eluted like the films of Examples C1 to C3. When the oligomer is eluted at the time of post-processing, since it acts as a foreign material in and and a film reduces production efficiency, the film which has little oligomer elution (hazard defense) is desired. For example, since ITO substrate or ITO protective film proceeds with heat treatment during ITO crystallization, oligomers are formed on the surface of ordinary PET film due to heat treatment. There may be a separate hard coating or inline coating for the oligomer block on the film, but the film of the above embodiment does not require such a separate coating process. From the results of Table 4, it can be seen that the films of Examples C1 to C3 do not have a haze deflection even without a separate hard coating layer for the oligomer block. Comparative Example 1 is a general optical PET biaxially oriented film, it is confirmed that the number of defendants of haze is relatively large, and a large amount of oligomer dissolution occurs at high temperature.

In Comparative Example 2, the coating of the coating layer reduced the haze change due to reduced oligomer elution, but was still unusable due to the large amount of oligomer elution. Comparative Example 3 lowered the Tg because of the CHDM content affects the crystallization with CHDM content is less than 80 mole ^_0/0, weakened immunity, yeolsuchukreul this was found greater, as well as changes in the haze degree relative is great due to heat . Remedy D

According to another embodiment, the polyester film comprises (i) constituents derived from a diol component comprising at least 90 mol% of 1,4-cyclohexanedimethanol, and (ii) 10 mol of isophthalic acid ^. A polyester resin comprising a structural unit derived from a dicarboxylic acid component containing ₀ or less, having a haze of 2% or less, and after 30 minutes of holding at 150 ^° C., the heat shrinkage is in the longitudinal and transverse directions. All may be 3% or less and the haze change may be less than 1%. Such a polyester resin may be induced by polymerization after the ester exchange reaction between the diol component and the dicarboxylic acid component.

The diol component comprises structural units derived from 90 mole ^_0/0 or more 1,4-cyclohexanedimethanol (CHDM), preferably CHDM to 98 mol%, more preferably at least 99 mole ^_0/0 or more Pohang. The diol component may further include a diol component other than CHDM. Specific examples of the diol component which may be further included as such are ethylene glycol, 1,3-propanediol, 1,2-octanediol, 1,3-octanediol, 2,3-butanediol, 1,3-butanediol , 1,4-butanediol, 1,5-pentanediol, 2,2-dimeryl-1,3-propanediol (neopennylglycol), 2-buryl-2-eryl-1,3-propanediol, 2,2-diethane—1,5-pentanediol, 2,4-diethal-1,5-pentanediol, 3-meryl-1,5-pentanediol, 1,1-dimeryl-1,5 —Pentanediol and mixtures thereof. The higher the CHDM fuel ratio contained in the diol component, the higher the Tg of the polymer, the better the heat resistance and the higher the hydrolysis resistance. However, since the structure of the CHDM increases the crystallinity, extrusion or film Determination can occur when drawing. Accordingly, the polyester resin may include isopral acid as the dicarboxylic acid component in order to lower the crystallization rate. When the isophthalic acid is included, the crystallization rate, which is excessively high as CHDM is included, may be lowered, and the handleability of the polymerizer may be increased by lowering the melting temperature (Tm) of the polymerizing agent. The Tg of the agent can be lowered to lower thermal properties such as heat resistance.

In the dicarboxylic acid component is less than the isophthaloyl ralsan 10 rule ^_0/0, preferably at most 0 mole ^_0/0 larger than 7 mol%, more preferably 0 mole ^_0/0 is more than 5 mole ^_0/0 include can do.

The dicarboxylic acid component is the isophthalic acid in addition to 80 mole ^_0/0 or more, preferably 80 mol ^_0/0 or more and less than 100 mole ^_0/0, more preferably less than than 90 mole ^_0/0 100 mole ^_0/0 May include terephthalic acid.

In addition, as said dicarboxylic acid component, Aromatic dicarboxylic acid, such as dimetal terephthalic acid, naphthalenedicarboxylic acid, orthophthalic acid; Aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and degandicarboxylic acid; Alicyclic dicarboxylic acid; And it may further include one or more selected from the group consisting of these esterified products. Accordingly, the polyester resin may include 1,4-cyclohexanedimethylene terephthalate as the main repeating unit. The polyester film has an intrinsic viscosity (at 25 ⁰ C) of 0.7 to 1.2 for filming, and preferably has a weight average molecular weight of 30,000 to 50,000 g / mol, especially 30,000 to 40,000 g / m. .

In addition, the polyester film may include a hard coating layer formed on one side of the film to improve brittleness. The hard coating layer may be made of a resin such as a thermoplastic resin, a thermosetting resin, an ionizing radiation (ultraviolet or electron radiation) curable resin, preferably (a) a bifunctional or higher acrylate monomer having ethylene glycol (EO), And (b) a hard coating composition comprising at least one of a polyfunctional urethane acrylate oligomer and a polyfunctional acrylate monomer having no ethylene glycol. The bifunctional or higher functional acrylate monomer having ethylene glycol is characterized in that when the number of functional groups thereof is n, the number of ethylene glycol contained is n to 2n, and the number average molecular weight is 100? To 200 ?. . For example, in the case of a bifunctional acrylate-based monomer, it may include 2 to 4 ethyl lian glycol, and may have a horizontal homogeneous molecular weight of 200 to 400. In addition, in the case of a trifunctional acrylate monomer, it may include 3 to 6 ethylene glycol, the number average molecular weight may be 300 to 600. Preferable examples of the bifunctional or higher I acrylate monomer include the compounds of Table 1 or mixtures thereof, but are not limited thereto. The content of the bifunctional or higher acrylate monomer having an ethylene glycol is preferably from 50 to 85% by weight, more preferably from 60 to 80% by weight, based on the solid content of the hard coating composition. The polyfunctional acrylate monomer is a total of two or more polyfunctional acrylate monomers having no ethylene glycol, preferably trifunctional or more.

Examples of polyfunctional acrylate monomers include 1,6-hexanediol diacrylate, 1,6-hexanoic dimethacrylate, butanediol diacrylate, butanediol dimethacrylate, tricyclodecane diac Lylate, cyclonucleic acid diacrylate, tris (2-hydroxyethyl) isocyanurate diacrylate, hydroxyl pivalaldehyde modified trimerylolpropane diacrylate, 1,4-butanedi diacrylate, Merallic diacrylate, modified metallic diacrylate, acrylate ester, cyclohexane dimethane dimethacrylate, 1,4-butanediol dimethacrylate, metallic dimethacrylate, trimethylolpropane tri Acrylate, Trimethylolpropane trimethacrylate, Pentaerythritol triacrylate, Tris (2-hydroxyethyl) isocyanurate triacryllay , Trifunctional acid ester, trifunctional acrylate ester, trifunctional methacrylate ester, dimetholpropane tetraacrylate, pentaerythritol tetraacrylate, pentaacrylate ester, pentaacrylic pentaacrylate The nucleus acrylate etc. can be used for a latent and dipentaerythride. The polyfunctional urethane acrylate-based oligomer is a bifunctional or more than one polyfunctional urethane acrylate oligomer. For example, all aliphatic or aromatic urethane acrylate oligomers are contained, and trifunctional or more than four functional groups are preferred. More preferred. Examples of the polyfunctional urethane acrylate oligomer include bifunctional urethane acrylate oligomers having a number average molecular weight of 1,400 to 25,000, trifunctional urethane acrylate oligomers having a number average molecular weight of 1,700 to 16,000, and a number average molecular weight of 1,000 tetrafunctional urethane. Acrylate oligomer, 6 functional urethane acrylate oligomer of number average molecular weight 818 to 2,600, 9 functional urethane acrylate oligomer of number average molecular weight 3,500 to 5,500, 10 functional urethane acrylate oligomer of number average molecular weight 3,200 to 3,900, number 15 functional urethane acrylate oligomer and the like with an average molecular weight of 2,300 to 20,000 can be used. The polyfunctional acrylate-based monomer and / or polyfunctional urethane arc barrels rate-based all-hitting meoeu I content and the like a hard coating based on solids with 9 to 50% by weight of the composition preferably 15 to 40 parts by weight ^_0/0, More preferred. On the other hand, the hard coating composition may include a photoinitiator, a solvent and the like, the type is not particularly limited.

The hard coating layer may have a thickness of 0,1 to 5 μιιι, preferably 0.5 to 3 ηι, and more preferably 1 to 2 μm. When the thickness of the hard coating layer is within the preferred range, it is advantageous to prevent cracks in the hard coating layer itself while preventing cracks or chipping points of the film. In addition, the hardness of the hard coating layer may be H to 5H. The polyester film may be prepared by a conventional method of biaxially stretching and heat setting the unstretched sheet in the longitudinal and transverse directions after the sheet is manufactured by melt extruding and engraving the polyester resin of the specific composition. . Melt-extrusion is preferably be done at a temperature of polyester resin + 30 ° C to Tm Tm + 60 ^o C. When the temperature of the extruder during the melt extrusion is less than Tm + 30 ^o C, the smooth melt does not occur, the viscosity of the extrudate becomes high, productivity is lowered, on the contrary, in the case of Tm + 60 ^o C, depolymerization by thermal decomposition The molecular weight may drop and problems with oligomers may occur. In addition, the nyaenggak is 30 ^o C or less is preferably formed at a temperature of, and takes place in more bar preferably from 15 ° C to 30 ^o C. The polyester film may be biaxially stretched in the longitudinal and transverse directions. In polyester, the defect is mostly due to the decomposition of the polyester chains due to hydrolysis, and especially at the minimum chain length, the brittleness of the film produced using the same can no longer withstand mechanical deformation such as elongation or bending. . Therefore, as a method for slowing down the decomposition rate, the resistance to the decomposition rate can be greatly increased by providing the orientation to the molecular procedure by adjusting the stretching conditions, that is, the stretching rate and the stretching ratio. With respect to the stretching conditions, biaxial stretching in both the longitudinal and transverse directions is carried out, the stretching temperature being in the range of glass transition temperature (Tg) + 5 ⁰ C to Tg + 50 ° C of the polyester resin, preferably Preferably Tg + 10 ° C. to Tg + 40 ° C. At this time, the lower the Tg, the better the ductility, but breakage may occur. In particular, when the stretching temperature is in the range of Tg + 10 ^° C. to Tg + 40 ° C., the brittleness of the produced film can be improved. At this time, the draw ratio may be 2 to 5, preferably 2.5 to 5, more preferably 2.5 to 4.0 in the longitudinal direction, 2.5 to 5 in the transverse direction, preferably 3 to 4.5, more preferably 3.2 to May be 4.2. The polyester film manufactured as Io I · may have a thickness of 12 μηη to 400 / 刑.

The polyester film has a haze of 2% or less, and after heat retention at 150 ^° C. for 30 minutes, and further 3 hours, thermal shrinkage is performed in the longitudinal direction (length direction or machine direction, MD) and in the transverse direction (width direction, TD). All are 3% or less, and the haze change is less than 1% after holding for 30 minutes at 150 ^° C. and further for 3 hours. In addition, the polyester film has a wavelength of 400 to 700 nm | The permeate may be at least 90%. The polyester film, such as iodine, is transparent and excellent in heat resistance, and exhibits excellent hydrolysis resistance, such as being able to maintain inherent excellent film properties even when exposed to high temperatures and humidity for a long time, and crystallization in silver Since there is no degradation in physical properties, it can be usefully used as an optical film for display.

Hereinafter, more specific examples of the polyester resin preparation according to the above embodiment are described.

Example D1

100 mol part of 1,4-cyclohexane dimethanol (CH DM), 1 mol part of isophthalic acid, and 99 mol part of terephthalic acid were put into the autoclave with a stirrer and a distillation column, and 0.01 weight of terephthalic acid of manganese acetate as a transesterification reaction catalyst. after you put a ^zero / _zero amount I, The transesterification reaction was carried out at 290 ^° C. After the transesterification reaction was completed, the Ti added as a polymerization catalyst 0Ό01 weight ^_0/0, and the mixture was stirred for 10 minutes. Subsequently, the reaction product was transferred to a second reactor equipped with a vacuum equipment, and then polymerized at 300 ° C. for 180 minutes to give poly (1,4-cyclohexane) having an IV (intrinsic viscosity) of 0.7501 and a weight average molecular weight of 35,000. Dimethylene terephthalate) (PCT) resin was obtained. The prepared PCT resin was dried at 150 ^° C. for 4 hours and melt-extruded through an extruder equipped with a screw at 280-290 ^° C., followed by contact with the angle of angle of 20 ^° C. to obtain an unstretched sheet. The sheet thus obtained was immediately preheated to 60 ^° C., and then stretched 2.9 times and 3.4 times in the longitudinal and transverse directions at 110 ° C., respectively, with longitudinal and transverse stretching speeds of 29 m / min and 30 m /, respectively. It was minutes. Subsequently, the stretched sheet was heat-set at 230 ° C. to prepare a polyester film having a thickness of 50.

Examples D2 to D5

PCT biaxially by performing the same procedure as in Example D1, except that the contents of 1,4-cyclohexanedimethanol (CH DM), isophthalic acid and terephthalic acid were each changed as shown in Table 5 below. A stretched film was prepared. IV and weight average molecular weight of the prepared PCT resin and the thickness of the film is shown in Table 5 together.

Comparative Example D1

100 mol parts of ethylene glycol and 100 mol parts of terephthalic acid were added to an autoclave in which a stirrer and a distillation column were triturated, and as a transesterification catalyst, manganese acetate was added in an amount of 0.01% by weight of terephthalic acid, followed by transesterification at 280 ° C. The reaction was carried out. After the transesterification reaction was completed, the tin oxide is 0.01 ^{_0/0-to-mouth} as a polymerization catalyst, and the mixture was stirred for 10 minutes. A polyaryl lenterephthalate (PET) resin with an IV of 0.61 and a weight average molecular weight of 34,000 was obtained. The prepared PET resin was dried at 150 ^° C. for 4 hours and melt-extruded through an extruder equipped with a screw at 270 ° C., followed by contact with the angle of angle of 20 ^° C. to obtain an unstretched sheet. The sheet thus obtained was immediately preheated to 60 ^° C. and then stretched 2.9 and 3.4 times in the longitudinal and transverse directions at 110 ° C., respectively, with longitudinal and transverse stretching speeds of 290 m / min and 300 m / It was minutes. The stretched sheet was then heated at 230 ° C. Fixed to prepare a polyester film having a thickness of 50 μπι.

Comparative Example D2 tolylene In the glycidyl cool to 100 molar parts, and terephthalic acid 100 mol parts of a stirrer O The autoclave was attached a distillation column in, and as a transesterification catalyst added manganese acetate with 0.01 ⁰ / _0. I the amount of Te Lev ralsan After, the transesterification was carried out at 280 ° C. After the completion of the transesterification reaction, 0.01 wt% of tin oxide was added as a polymerization catalyst and stirred for 10 minutes. Polyether lenterephthalate (PET) resin with an IV of 0.61 and a weight average molecular weight of 34,000 was obtained. Subsequently, the reaction product was transferred to a second reactor equipped with a vacuum equipment, and then polymerized at 260 ^° C. for 180 minutes to obtain a polyylene terephthalate (PET) resin having an IV of 0.75 and a weight average molecular weight of 45,300. Obtained.

Thereafter, a polyester film was prepared by the same method as Comparative Example D1 using the polyetherene terephthalate (PET) resin.

Comparative Example D3

A PCT resin was obtained through the same method as in Example D1, except that 75 mol parts of CHDM was used, and a polyester film was prepared in the same manner as in Example using the PCT resin.

Comparative Example D4 Except that no isophthalic acid was used, a PCT resin was obtained by the same method as Example D1, and then a polyester film was prepared by the same method as Example D1 using the PCT resin. .

Comparative Example D5 A PCT resin was obtained through the same method as described above except that 15 mol parts of isophthalic acid was used, and then the same composition as in Example D1 was performed using the PCT resin. A polyester film was prepared through the method.

Example D6 Triylene glycol diacrylate (SR272, manufactured by Satomer), polyfunctional urethane acrylate oligomer (MU9500, Miwon Specialty Chemical Co., Ltd.), and photoinitiator (1-184, BASF 人) based on solid content respectively, the hard coating composition was prepared by adding to 15 parts by weight of the composition Merrill 100 parts by weight of the hair Kerron and stirred comprising 74 parts by weight ^_0/0, 18 weight ^_0/0, and 8% by weight. After applying the hard coating composition to one surface of the polyester film obtained in Example D1 by a die coating method, the solvent is dried for about 1 minute through a 70 ^° C. drying chamber, a high-pressure mercury lamp, xenon lamp, etc. Ultraviolet rays radiated from the UV lamps were cured by irradiating with 1,000 mJ / cm ² light quantity, thereby preparing a polyester film having a hard coating layer having a thickness of 1 μη \.

Examples D7 to D10 Using the polyester films prepared in Examples D2 to D5, the same method as in Example D6 was performed except that the thicknesses of the hard coat layers were formed as shown in Table 6 below, respectively. To prepare a polyester film formed with a hard coating layer.

Comparative Examples D6 to D10 Using the polyester films prepared in Comparative Examples D1 to D5, the same method as in Example D6 was performed except that the thicknesses of the hard coat layers were formed as shown in Table 6 below. To prepare a polyester film formed with a hard coating layer.

The films prepared in Examples D1 to D10 and Comparative Examples D1 to D10 are shown together in Tables 5 and 6, respectively, in which heat shrinkage, viscosity (IV), permeation and change in haze were calculated. table

Table 6

Initial transmission (%) 92 91 91 91.3 91 89 90 90 90 Initial Hz 0.30 0.39 0.45 0.58 0.2 1.0 0.9 1.2 0.45 Haze after aging

0.30 0.39 0.45 0.58 0.2 4.5 2.5 2.3 1.8 (150 ° C, 30min)

Haze after Hayes

0.31 0.39 0.47 0.59 0.22 5.3 3.1 3.5 2.3 (150 ° C, 3 hr)

Haze change

-----3.50 1.60 1.10 0.50 1.35 (150 ° C, 30min)

Haze rate of change

0.01 0.02 0.01 0.02 4.30 2.20 2.30 4.00 1.85 (150 ° C, 3 hr)-

From the results of Table 5, it can be seen that the films of Examples D1 to D5 are not only excellent in thermal contraction rate and permeateol, but also very low in number of haze. The substrate for heat-resistant optics or the heat-resistant material film should not dissolve oligomers like the films of Examples D1 to D5 above, which is advantageous for post processing, optically transparent, and oligomers should not elute. When the oligomer is eluted at the time of post-processing, since it acts as a foreign material in and and a film reduces production efficiency, the film which has little oligomer elution (hazard defense) is desired. For example, a ΠΌ substrate or an ITO protective film undergoes heat treatment during processing due to ITO crystallization, and thus oligomers are generated on the surface of a general PET film. As a result of Table 6, there is a case in which a separate hard coating or inline coating may be performed by using the oligomeric blocking, but the film of the embodiment does not require such a separate coating process. From the results of Table 6, it can be seen that the films of Examples D1 to D5 are hard-coated, and there is no change in haze even without eliminating the blocking. Comparative Example D1 is a general optical PET, and Comparative Example D2 solidifies the resin of 1 to increase Tg and Tm to improve heat resistance. However, it can be seen that the law of the haze is relatively large, and a large amount of oligomer dissolution occurs at high temperature. Specifically, the oligomer elutes to the film surface after the heat resistance test in the oven, thereby raising the haze. At this time, white oligomers are collected when the film surface is rubbed with a spatulator. In the specification of the present invention, the value of the oligomer elution can be confirmed by Haze, and the SEM photographs of FIGS. (2,000 times), the oligomer shape can be reconfirmed. In Comparative Example D3, the CHDM content is less than 80 mol%, the Tg is lowered due to the CHDM content affecting crystallization, and the heat resistance is weakened.

In addition, when applying only CHDM without IPA as in Comparative Example D4, the crystallization rate is very fast, which leads to a state in which the film cannot be formed due to crystallization during melt extrusion. If the IPA content is out of the desired range as in Comparative Example D5, the crystallization rate is reduced, resulting in an amorphous state | The resin is obtained and the Tg is lowered, thereby weakening the heat resistance. Therefore, oligomer elution occurs at high temperature, and application to heat-resistant optical materials is impossible.

Remedy E

According to yet another embodiment, the polyester film (D 1,4- cyclohexanedimethanol methanol configuration danwoo derived from a diol component containing 90 mol ^_0/0 more than |, and (Π) terephthalic acid 80 mol ⁰ Polyester resin comprising a structural unit derived from a dicarboxylic acid component containing at least / ₀ , and a spherical monodisperse particles of 200 to 3,000 ppm relative to the polyester resin, the polyester resin I The vitrification temperature is not lower than 88 ° C., and after 30 minutes of holding at 15 CTC, the heat shrinkage may be 3% or less in both the longitudinal and the transverse directions. It can be induced by polymerization.

The diol component is more than 90 mole ^_0/0 1,4-cyclohexanedimethanol comprises the constitutional unit derived from methanol (CHDM), preferably from the CHDM 98 mole ^_0/0, more preferably at least 99 mole ⁰ / _It contains ₀ or more. The diol component may further include a diol component other than CHDM. Specific examples of the diol component that may be further included include ethylene glycol, 1,3-propanediol, 1,2-octanediol, 1,3-octanediol, 2,3—butanediol, 1,3-butanediol , 1,4-butanediol, 1,5-pentanediol, 2,2-dimeryl-1,3-propanediol (neopennylglycol), 2-buryl-2-eryl-1,3- Propanediol, 2,2-diaryl-1,5-pentanediol, 2,4-diaryl-1,5-pentanediol, 3-metal-1,5-pentanediol, 1,1-dimeryl- 1,5-pentanediol and these mixed wool. The polyester resin is the dicarboxylic acid component as the 80 mol% or more, the wind directly from 80 mole ⁰ / ᄋ or more and less than 100 mole ^_0/0, more preferably less than ^_0/0 90 mol to 100 mol% of Te The higher the CHDM ratio contained in the diol component, the higher the Tg of the polymer, the better the heat resistance and the higher the hydrolysis resistance, but the higher the CHDM structure, the higher the crystallinity. When extruded or stretched, crystallization may occur. Accordingly, the polyester resin may include isophthalic acid in addition to terephthalic acid as the dicarboxylic acid component in order to lower the crystallization rate.

The polyester resin is an isophthalic acid 10 mol ^_0/0 or less, preferably 0 mol% second and I · 7 mole ^_0/0 or less, more preferably in an amount of more than 0 mole ^_0/0 is more than 5 mole ^_0/0 It may include.

In addition, as said dicarboxylic acid component, Aromatic dicarboxylic acid, such as dimethyl terephthalic acid, naphthalene dicarboxylic acid, orthophthalic acid; Aliphatic dicarboxylic acids such as adipic acid, azelaic acid, sebacic acid, and decanedicarboxylic acid; Alicyclic dicarboxylic acid; And it may further include one or more selected from the group consisting of these esterified products. Accordingly, the polyester resin may include 1,4-cyclonucleic acid dimethylene terephthalate as a main repeating unit.

The polyester film is 0.6 ~ 1.2 £ | for filming. It has an intrinsic viscosity (at 25 ° C) and preferably has a weight average molecular weight of 30,000 to 50,000 g / mol, especially 30,000 to 40,000 g / m.

The polyester resin may comprise 200 to 3,000 ppm, preferably 400 to 1,500 ppm of spherical monodisperse particles. By including the spherical monodisperse particles to increase the slip properties of the polyester film, it is possible to solve the difficulty of winding due to the self-adhesion of the polyester film. When the content of the particles satisfies the I range of 400 to 1,500 ppm, the friction coefficient of the film can be appropriately lowered without excessive rise of haze, thereby improving the gripability of the film. The spherical monodisperse particles may have a flatness of 0.1 to 2.5, preferably 0.1 to 2.0 μιη. It may have a uniform particle size, and the particle diameter ratio may be 0.5 to 1.2, preferably 0.8 to 1.2, more preferably 0.8 to 1.1. The particle diameter ratio may be expressed as the ratio of the average value of the long diameter of the spherical monodisperse particles to the average value of the short diameter. The friction coefficient of the film can be set to 0.8 or less while preventing the haze from increasing due to the occurrence of no stage or dispersion. The spherical monodisperse particles may be inorganic particles or organic particles, but preferably inorganic particles, for example, may be at least one selected from the group consisting of spherical silica, spherical titanium oxide, and spherical zirconium. In general, when the particles are added to the finished polyester resin, there is a problem in dispersibility, but the polyester film includes spherical monodisperse particles having an average particle diameter and a particle diameter ratio in the above range. I can solve it. Therefore, the spherical monodisperse particles may be added in the middle of the polymerization of the polyester resin, or may be included in the polyester film by compounding by adding to the finished polyester resin. In addition, the polyester film may include a hard coating layer formed on one side of the film to improve brittleness. The hard coating layer may be made of a resin such as a thermoplastic resin, a thermosetting resin, an ionizing radiation (ultraviolet ray or an electron ray) curable resin, preferably (a) a bifunctional or higher acrylate monomer having an ethylene glycol (EO), And (b) at least one of a polyfunctional urethane acrylate based oligomer and a polyfunctional acrylate monomer having no ethylene glycol. The bifunctional or higher acrylate monomer having ethylene glycol is characterized in that when the number of functional groups thereof is n, the number of ethylene glycol contained I is π to 2n, and the number average molecular weight is 100 to 200 η. It is done. For example, in the case of a bifunctional acrylate monomer, it may include two to four ethylene glycol, and may have a horizontal homogeneous molecular weight of 200 to 400. In addition, in the case of a trifunctional acrylate monomer, it may include three to six ethylene glycol, the number average molecular weight may be 300 to 600. Preferred examples of the bifunctional or higher acrylate monomers include those of Table 1 above. Compounds or mixtures thereof are possible, but are not limited to these. The content of the bifunctional or higher acrylate monomer having ethylene glycol is preferably 50 to 85% by weight, more preferably 60 to 80% by weight based on the solids content of the hard coating composition. The polyfunctional acrylate monomer is a bifunctional or more than one polyfunctional acrylate monomer having no ethylene glycol, and is preferably trifunctional or more.

Examples of the polyfunctional acrylate monomers include 1,6-hexanediol diacrylate, 1,6—nucleic acid diol dimethacrylate, butanediol diacrylate, butanediol dimethacrylate, and tricyclodecane diacrylate Latex, cyclohexane diacrylate, tris (2-hydroxyethyl) isocyanurate diacrylate, hydroxyl pivalaldehyde modified trimeryl to propane diacrylate, 1,4-butanedi diacrylate, Merallic diacrylate, modified metallic diacrylate, acrylate esters, cyclonucleic acid dimethanol dimethacrylate, 1,4-butanediol dimethacrylate, metallic dietaacrylate, triarylolpropane triacrylic Triacrylate, trimethylolpropane trimethacrylate, pentaerythritol tris, tris (2-hydroxyeryryl) isocyanurate triacrylate , Trifunctional acid ester, trifunctional acrylate ester, trifunctional methacrylate ester, dimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, pentaacrylate ester, dipentaerythrite pentaacrylate, di Pentaerythritol hexaacrylate and the like can be used. The polyfunctional urethane acrylate oligomer is a bifunctional polyfunctional urethane acrylate oligomer, and includes, for example, both aliphatic or aromatic urethane acrylate oligomers, preferably at least trifunctional and at least tetrafunctional. More preferred. Examples of the polyfunctional urethane acrylate oligomer include bifunctional urethane acrylate oligomers having a number average molecular weight of 1,400 to 25,000, trifunctional urethane acrylate oligomers having a number average molecular weight of 1,700 to 16,000, and a number average molecular weight of 1,000 tetrafunctional urethane arc. Lallylate oligomers, 6 functional urethane acrylate oligomers with number average molecular weights 818 to 2,600, 9 functional urethane acrylate oligomers with number average molecular weights 3,500 to 5,500, 10 functional urethane acrylates with number average molecular weights 3,200 to 3,900 Yit oligomer, 15 functional urethane acrylate oligomer of the number average molecular weight 2,300-20,000, etc. can be used. The polyfunctional arc barrels rate-based monomer and / or polyfunctional urethane arc barrels hitting rate based come meoeu i content and the like a hard coating based on solids with 9 to 50% by weight of the composition preferably 15 to 40 parts by weight ^_0/0 More preferably. On the other hand, the hard coating composition may include a photoinitiator, a solvent and the like, the type is not particularly limited.

The hard coating layer may have a thickness of 0.1 to 5 μ (η, preferably 5 to 3 μπι, and more preferably 1 to 2 μηι. When it is inside, it is advantageous to prevent cracks in the hard coat layer material while preventing cracks or chipping points of the film, and the hardness of the hard coat layer may be H to 5H.

The polyester film may be prepared by a conventional method of biaxially stretching and heat setting the unstretched sheet in the longitudinal and transverse directions after the sheet is manufactured by melt extruding and engraving the polyester resin of the specific composition. .

Melt extrusion is preferably performed at a temperature of Tm + 30 ^o C to Tm + 60 ^o C of the polyester resin. If the temperature of the extruder during the melt extrusion is less than Tm + 30 ° C, the smooth melt does not occur, the viscosity of the extrudate is high, productivity is lowered, if the temperature exceeds Tm + 60 ^o C, on the contrary, depolymerization by thermal decomposition ᅵ Molecular weight drops and oligomers may cause problems. In addition, the nyaenggak is preferably formed at a temperature below 30 ° C, it takes place at a quite bar preferably from 15 ° C to 30 ^o C. The polyester film may be biaxially stretched in the longitudinal and transverse directions. In polyester, the defect is mostly due to the decomposition of the polyester chains due to hydrolysis, and especially at the minimum chain length, the brittleness of the film produced using it is no longer able to withstand mechanical deformations such as elongation or stiffness. . Therefore, as a method for slowing down the decomposition rate, the resistance to the decomposition rate can be greatly increased by providing an orientation to the molecular chain by adjusting the stretching conditions, that is, the stretching rate and the stretching ratio. In relation to the stretching conditions, biaxial stretching in both the longitudinal and transverse directions is carried out, the stretching temperature being in the range of glass transition temperature (Tg) + 5 ° C to Tg + 50 ° C of the polyester resin, preferably T _{g +} 10 ^o C to Tg + 40 ^o C. At this time, the lower the Tg, the better the ductility, but breakage may occur. In particular, when the stretching temperature is in the range of Tg + 10 ^° C. to Tg + 40 ° C., the brittleness of the produced film can be improved. At this time, the draw ratio may be 2 to 5 times, preferably 2.5 to 5 times, more preferably 2.5 to 4.0 times in the longitudinal direction, 2.5 to 5 times in the transverse direction, preferably 3 to 4.5 times, more Preferably 3.2 to 4.2 times. The film is heat fixed after stretching, the film is relaxed in the longitudinal and / or transverse direction after starting the heat fixing, the heat setting temperature range is preferably 200 ~ 260 ^° C. The polyester film prepared as Iojan may have a thickness of 12μηι to 400μπι.

In addition, the polyester film may include various additives such as a conventional electrostatic agent, an antistatic agent, a sunscreen, an antiblocking agent, and other inorganic lubricants within a range that does not impair the above effects. Since the polyester film such as iodine contains spherical monodisperse particles, the static friction coefficient and the dynamic friction coefficient may each be 0.8 or less, and preferably may be 0.05 to 0.7. Since the polyester film has a static friction coefficient and a dynamic friction coefficient of 0.8 or less, respectively, it can be easily wound in the state of.

In addition, the polyester film is maintained at 150 ° C. for 30 minutes, the heat shrinkage is less than or equal to 3% in both the longitudinal (length or machine direction, MD) and transverse (width, TD), and 30 minutes at 150 ^o C After maintenance, the haze change after 3 hours of further maintenance is 2% or less, preferably 0.6% or less, and the total light transmission may be 90% or more. Like IoS, the polyester film is transparent and excellent in heat resistance, and exhibits excellent hydrolysis resistance such as being able to maintain inherent excellent film properties even when exposed to high temperature and humidity for a long time. Since there is no degradation of properties and less oligomer dissolution, it can be usefully used as an optical film for display. Hereinafter, more specific examples of the polyester resin preparation according to the above embodiment are described.

Example E1

90 mole parts of 1,4-cyclohexanedimethanol (CHDM), 10 mole parts of diallyl glycol, 90 mole parts of terephthalic acid and 10 mole parts of isophthalic acid were added to an autoclave equipped with a stirrer column distillation column and acetic acid as a transesterification catalyst. was added manganese in an amount of 0.01 volume ^_0/0 of Lev ralsan of Te, it was carried out an ester exchange reaction in 29CTC. After completion of the ester exchange reaction, 0.001% by weight of Ti was added as a polymerization catalyst and stirred for 10 minutes. Subsequently, the reactants were transferred to a second reactor equipped with a vacuum equipment, and then polymerized at 300 ^° C. for 180 minutes to give a poly (1,4-cyclohexanediene) having an IV (intrinsic viscosity) of 0.75 and a weight average molecular weight of 35,000. Rylene terephthalate) (PCT) resin was obtained.

To the PCT resin, silica particles (sylisia SKM-407, fuji sylysia) (.) Having an average particle diameter of 0.5 μηη and a particle size ratio of 0.8 were added to the PCT resin in an amount of 600 ppm relative to the PCT resin, Compounding a PCT resin containing silica particles by compounding using an extruder, PCT resin containing silica particles was dried for 4 hours at 150 ° C and equipped with a screw at 280 ~ 290 ° C After melt extruding through an extruder, an unstretched sheet was obtained by bringing the corner angle angled at 20 ^° C. to an unstretched sheet, which was preheated immediately to 60 ° C., and then stretched three times in the longitudinal and transverse directions at 11 CTC, respectively. At this time, the longitudinal and lateral stretching speeds were 29 m / min and 30 m / min, respectively.The stretched sheet was then heat set at 230 ° C. to prepare a polyester film having a thickness of 50 μιτι.

A polyester film was prepared by performing the same process as in Example E1 except that Examples Ε2 to Ε4, and Comparative Examples E1 to Ε5 spherical monodisperse particles were of the kind, particle size, and content as shown in Table 7 below. It was. For the films prepared in Examples El to E4 and Comparative Examples E1 to E5, the permeation, haze, coefficient of friction, heat shrinkage, and the like, are shown in Table 7 below.

Referring to Table 7, the polyester film of Examples E1 to Ε4 has a low shrinkage and haze value, there is no change over time, it can be confirmed that the excellent stretchability and total light transmission. It can be seen that in Comparative Example E1, the particle content was insufficient and the coefficient of friction was high due to high friction coefficient. In addition, Comparative Example Ε2 did not contain particles, so the coefficient of friction was too high to determine the exact coefficient of friction.

Τ Τ ΛΛ Λ * —Γ ^,

In addition, when the particle content is excessive, it affects the stretchability due to the dispersibility problem of the particles. In Comparative Example E4 containing excess particles, the film was not stretched.

On the other hand, in Comparative Examples E3 and E5, the particle size ratio and particle diameter exceeded the appropriate ranges, the film had a high haze, and the dispersibility of the particles was not good, resulting in breakage of the film, so that a good film could not be obtained. This is presumably because when the dispersibility of the particles is not good, the resin crystallization rate is partially accelerated to make the resin difficult to film.

Property evaluation method

Evaluation of the physical properties of the previous examples and comparative films was performed according to the following procedure.

Heat shrinkage

A 10 cm × 10 cm square film sample was used with the film cut so that one edge was parallel to the machine direction (longitudinal) and the other edge was perpendicular to the machine direction (lateral). After holding the film for 30 minutes in an oven at 150 ° C. air is circulated, the sample was taken out to measure the length change in the longitudinal and transverse directions at the salon to calculate the longitudinal and transverse thermal shrinkage according to the following formula.

Thermal contraction (%) = [(L-L) / L] X 100 where L is the length before heat treatment and L is the length after heat treatment.

Viscosity

The resulting resin ortho-chlorophenol (σ-chlorophen) was dissolved in a 1 wt. ^_0/0 solution prepared in the two as measured by Ostwald (Ostwald) viscometer of 25 ⁰ C | in accordance with Equation (1) Intrinsic viscosity Relative viscosity was determined by comparison with.

[Equation 1] B t

qr: relative viscosity

B ： Correction coefficient of viscosity pipe

t: Blank test of orthochlorophenol. Measurement time (sec) t: Measurement time of sample solution (sec) c: 2.4

Penetration

Permeation | transmission was measured using ASTM ^[ D ^] haze meter (model name: NDH-5000W, the Nippon Denshoku Kogyo Co., Ltd. make) in ASTM-D 1003.

Haze

Specimens were fabricated using a 10 cm × 10 cm square film sample, with one edge cut parallel to the machine direction (vertical) and the other edge perpendicular to the machine direction (lateral). Measure the haze (%) by using a haze meter (model name: NDH-5000W, manufactured by Nippon Denshoku Kogyo Co., Ltd.) for the specimen, and then place the film in an oven at 150 ° C. for 30 minutes for air circulation. After holding, the sample was taken out, and the haze (%) was again calculated using the haze meter, and then the haze change value was calculated through Equation 2 below. In addition, the haze value after heat treatment (aging) at 150 ° C. for 3 hours was also measured in the same manner to calculate the haze change value.

[Equation 2] haze change (%) = [haze after heat treatment (%)]-[haze before heat treatment (%)]

Coefficient of friction According to the ASTM D1894 test method, the specimen was placed horizontally on the test table of the friction coefficient accumulator, and the static friction coefficient and the dynamic friction coefficient were measured by driving the test equipment at a constant displacement speed.

Change over time

After the film cut to A4 size was loaded to 200 g or more, the film loading state after 24 hours was classified and evaluated as follows.

O ： Press marks and scratches were observed when the surface of the stacked film was observed.

X ： Press marks and scratches are not observed when the stacked film surface is observed.

Extensibility

Manufacture of the film | Under the same process conditions, the number of breaks occurring in the longitudinal and transverse stretching was measured to evaluate the stretchability.

For five consecutive draws, the following criteria were evaluated:

Good: 0 to 1 fracture

-Bad: Breaks more than 3 times

x: sustained fracture (no stretching continuity).

Adhesiveness of each film prepared in the adhesive example and the comparative example was determined by the following method:

By the test method of the KDS 6711-92 horizontally and vertically so that a knife 1mm intervals do i cross-cuts (Crass-cut) the two |, after attachment to the tape was quickly ^[[is measured by the following method. When the residual amount of the film is 95% or more, excellent, 90 to 80% was good, less than 80% was evaluated as poor.

Autoclave treatment The film (width x length = 10 cm x 2 cm) was placed in an autoclave and fixed, and the autoclave was filled with 2 L of water, and then the autoclave was closed and heated. The temperature of the autoclave was adjusted to 120 ° C. and the pressure was raised to 1.2 atm for 72 hours. After the set time, the autoclave was turned off automatically. After opening the outlet valve, the film was taken out and the corresponding physical properties were measured.

Mechanical properties

Tensile strength and elongation at break were measured according to DIN EN ISO 527-1 3, respectively.

In the above, the present invention has been described with reference to the above embodiments, which are only examples, and the present invention includes various modifications and other equivalent embodiments which are obvious to those skilled in the art. It should be understood that this can be done within the scope of the claims appended hereto.

Claims

1. (i) a component derived from a diol component comprising at least 90% by weight of 1,4-cyclohexanedimethanol, and

(ii) comprises a polyester resin containing a constituent unit derived from a dicarboxylic acid component containing isophthaloyl ralsan of from 3 to 25 mole ^_0/0,

Haze is 2% or less, after 1 hour holding at 150 ° C., the heat shrinkage is 3% or less in both the longitudinal and transverse direction and the haze defendant 미만 less than 1%, polyester film.

2. The method of paragraph 1,

After the polyester film is maintained at 150 ° C. for 1 hour, the heat shrinkage is less than 1.5% in both the longitudinal and transverse directions and the haze change is less than 1%, the polyester film.

3. The method of claim 2, wherein the diol component comprises the 1,4-cyclohexane dimethanol 98 mol ^_0/0 or higher, the polyester film.

4. The polyester film according to item 3, wherein the dicarboxylic acid component comprises 5 to 18 mol ⁰ / o of the isopral acid.

5. The method of claim 4, wherein the dicarboxylic acid component containing the isophthaloyl ralsan 5 to 15 mole ^_0/0, poly ester film to.

6. The method of clause 4, The dicarboxylic acid component containing Te Lev ralsan of 82 to 95 mole ^_0/0, the poly film in the hotel's.

7. Paragraph 1 according to claim 1,

The polyester film is 50% or more of the elongation retention after 72 hours treatment at 120 ^° C and 1.2 atm.

8. The process of clause 1,

Polyester, wherein the polyester film is biaxially stretched in the longitudinal stretching ratio of 2 to 5 times and transverse stretching ratio of 2.5 to 5 times

9. Paragraph 1 according to claim 1,

The polyester film further comprises a coating layer containing one or more resins selected from the group consisting of polyester resins, acrylic resins, polyurethane resins, queramine resins and oxazoline resins on one surface thereof. ester

10. The polyester film according to item 1, wherein the polyester film further comprises a hard coating layer on one surface.

11. Paragraph 1 according to claim 1,

The polyester film of which said polyester resin further contains 200-3,000 ppm I spherical monodisperse particle.

12. (1) (i) a diol component comprising at least 90 ^_0/0 1,4-cyclohexanedimethanol, and (ii) 3 to 25 dicarboxylic acid component containing isophthaloyl ralsan of rule ^_0/0 Poly by polymerizing Preparing an ester resin;

(2) melting and extruding the polyester resin to form a sheet;

(3) biaxially stretching the molded sheet in the longitudinal and 힁 directions; And

(4) A method for producing the polyester film of claim 1, comprising the step of heat setting the biaxially stretched sheet.

13. The process of clause 12, wherein in step (3) the molded sheet is

The glass transition temperature (Tg) of the polyester resin (Tg) + 5 ° C to Tg ₊ 50 ° C in the elongation ratio of 2 to 5 times in the longitudinal direction and 2.5 to 5 times in the transverse direction in both the longitudinal and transverse directions 25 to 200 The manufacturing method of the polyester film extended | stretched at the speed of m / min.

14. Optical film comprising the polyester film of any one of claims 1-11.

15. A display paper containing the polyester film of any one of items 1 to 11.