WO2023101191A1 - Polyester-based film and production method therefor - Google Patents

Polyester-based film and production method therefor Download PDF

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Publication number
WO2023101191A1
WO2023101191A1 PCT/KR2022/015165 KR2022015165W WO2023101191A1 WO 2023101191 A1 WO2023101191 A1 WO 2023101191A1 KR 2022015165 W KR2022015165 W KR 2022015165W WO 2023101191 A1 WO2023101191 A1 WO 2023101191A1
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Prior art keywords
polyester
based film
less
film
filler
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PCT/KR2022/015165
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French (fr)
Korean (ko)
Inventor
임병재
허영민
연제원
Original Assignee
에스케이마이크로웍스 주식회사
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Publication of WO2023101191A1 publication Critical patent/WO2023101191A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/07—Flat, e.g. panels
    • B29C48/08—Flat, e.g. panels flexible, e.g. films
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
    • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
    • B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
    • B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
    • C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
    • C08G63/16—Dicarboxylic acids and dihydroxy compounds
    • C08G63/18—Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
    • C08G63/181—Acids containing aromatic rings
    • C08G63/183—Terephthalic acids
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
    • C08G63/02—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds
    • C08G63/12—Polyesters derived from hydroxycarboxylic acids or from polycarboxylic acids and polyhydroxy compounds derived from polycarboxylic acids and polyhydroxy compounds
    • C08G63/16—Dicarboxylic acids and dihydroxy compounds
    • C08G63/18—Dicarboxylic acids and dihydroxy compounds the acids or hydroxy compounds containing carbocyclic rings
    • C08G63/199—Acids or hydroxy compounds containing cycloaliphatic rings
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
    • C08K3/013—Fillers, pigments or reinforcing additives
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/34—Silicon-containing compounds
    • C08K3/36—Silica
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K7/00—Use of ingredients characterised by shape
    • C08K7/16—Solid spheres
    • C08K7/18—Solid spheres inorganic
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
    • C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/002—Physical properties
    • C08K2201/005—Additives being defined by their particle size in general

Definitions

  • Embodiments relate to a polyester-based film and a method for producing the same.
  • Electronic boards such as circuit boards, which are essential components in electronic devices, have conductive patterns formed on insulating base films, and in particular, flexible printed circuit boards (FPCB) mounted on smart devices such as mobile phones and tablet PCs are representative.
  • FPCB flexible printed circuit boards
  • FCCL Flexible Copper Clad Laminate
  • Flexible copper clad laminates are generally manufactured by laminating copper foil on one side or both sides of a base film. was used as a base film.
  • liquid crystal crystalline polymers or polyimide-based resins have problems in that they have high unit price and high permittivity and low moisture resistance.
  • polyester-based resins are excellent in mechanical properties such as durability, chemical resistance, heat resistance, and optical properties such as transparency, they are widely used as various industrial materials such as display devices as well as materials such as fibers, films, and molded products.
  • polyester-based films manufactured using such polyester-based resins have excellent heat resistance and hydrolysis resistance, but have difficulties in processes such as winding due to soft and high surface friction coefficients, and poor driving performance. .
  • Korean Patent Publication No. 2006-0060082 discloses a flexible copper-clad laminate film in which the surface of a polyimide film is modified and applied to copper foil, but such a polyimide film has a high unit price and high permittivity and low moisture resistance. There is a limit to performance improvement, and since the film is immersed in a solution in the reforming step, moisture resistance may be further deteriorated.
  • Patent Document 1 Korean Patent Publication No. 2006-0060082
  • embodiments are intended to provide a polyester-based film and a method for manufacturing the same, which are excellent in processability such as winding and running performance, as well as mechanical properties and optical properties.
  • a polyester-based film includes a co-polyester-based resin in which a diol and two or more dicarboxylic acids are copolymerized; and a filler, and R d according to Equation 1 below is 2.5 or less.
  • R max is the maximum height roughness ( ⁇ m) of the polyester film
  • R a is the center line average roughness ( ⁇ m) of the polyester-based film.
  • a method for manufacturing a polyester-based film includes preparing a resin composition by mixing a co-polyester-based resin in which diols and dicarboxylic acids are copolymerized with a filler; Melting and extruding the resin composition to prepare an unstretched sheet; preparing a stretched sheet by first stretching the unstretched sheet in a first direction and secondarily stretching the unstretched sheet in a second direction perpendicular to the first direction; and preparing a polyester-based film by heat-setting the stretched sheet at 200° C. to 260° C., wherein the polyester-based film has an R d of 2.5 or less according to Formula 1.
  • the polyester-based film according to the embodiment has excellent processability such as winding and running performance of the film by controlling the surface roughness, as well as excellent mechanical properties and optical properties.
  • the polyester-based film has excellent dispersibility while satisfying 10-point average roughness (R z ), center line average roughness (R a ), and maximum height roughness (R max ) within preferred ranges, thereby providing mechanical properties and optical properties. It is possible to improve the surface properties at the same time without degrading.
  • Example 1 shows a scanning electron microscope (SEM) image of the polyester film of Example 1.
  • Figure 2 shows a scanning electron microscope (SEM) image of the polyester film of Example 2.
  • Figure 3 shows a scanning electron microscope (SEM) image of the polyester-based film of Example 3.
  • Figure 4 shows a scanning electron microscope (SEM) image of the polyester-based film of Comparative Example 1.
  • Embodiments are not limited to the contents disclosed below, and may be modified in various forms unless the gist of the invention is changed.
  • a polyester-based film includes a co-polyester-based resin in which a diol and two or more dicarboxylic acids are copolymerized; and a filler, and R d according to Equation 1 below is 2.5 or less.
  • R max is the maximum height roughness ( ⁇ m) of the polyester film
  • R a is the center line average roughness ( ⁇ m) of the polyester-based film.
  • a polyester film is generally manufactured using a roll, it is important to improve fairness such as winding property and driving performance in order to improve the quality of the polyester film produced.
  • organic and inorganic additives have been used to improve fairness such as film winding and running performance, but when these additives are used, there is a problem in that mechanical properties such as tensile strength and modulus, in particular, transparency are greatly deteriorated.
  • mechanical properties such as tensile strength and modulus, in particular, transparency are greatly deteriorated.
  • processability may be improved, but mechanical properties such as tensile strength and modulus of the prepared polyester film are lowered, and in particular, haze is reduced. increased, resulting in very low transparency.
  • the polyester-based film according to the embodiment includes a co-polyester-based resin in which a diol and two or more kinds of dicarboxylic acids are copolymerized and a filler, thereby effectively controlling the surface roughness of the film to improve fairness such as winding and driving performance of the film.
  • the polyester film has excellent dispersibility while satisfying 10-point average roughness (R z ), center line average roughness (R a ) and maximum height roughness (R max ) within preferred ranges, thereby improving mechanical properties and optical properties. Surface properties can also be improved at the same time without deterioration.
  • the polyester-based film has an R d of 2.5 or less according to Formula 1 below.
  • R max is the maximum height roughness ( ⁇ m) of the polyester-based film
  • R a is the center line average roughness ( ⁇ m) of the polyester-based film.
  • the R d represents the ratio between the surface roughness characteristics of the polyester film, and the R d may be 2.3 or less, 2.0 or less, 1.8 or less, or 1.6 or less, 0.3 to 2.5, 0.5 to 2.3, 0.5 to 2.1 , 0.6 to 1.8, 0.8 to 1.6 or 0.9 to 1.6.
  • the R d value satisfies the above range, it is possible to simultaneously improve mechanical properties and optical properties while controlling the surface roughness to a more preferable range to improve fairness such as winding and running performance of the film, and in particular, transparency by reducing haze. can maximize
  • the 10-point average roughness (R z ) of the polyester film is 0.8 ⁇ m or less.
  • the 10-point average roughness (R z ) of the polyester film may be 0.7 ⁇ m or less, 0.6 ⁇ m or less, 0.5 ⁇ m or less, or 0.3 ⁇ m or less, 0.01 ⁇ m to 0.8 ⁇ m, 0.05 ⁇ m to 0.6 ⁇ m, or 0.1 ⁇ m. ⁇ m to 0.5 ⁇ m or 0.15 ⁇ m to 0.3 ⁇ m.
  • the center line average roughness (R a ) of the polyester-based film is 0.05 ⁇ m or less.
  • the center line average roughness (R a ) of the polyester film may be 0.04 ⁇ m or less, 0.03 ⁇ m or less, or 0.02 ⁇ m or less, 0.001 ⁇ m to 0.05 ⁇ m, 0.005 ⁇ m to 0.04 ⁇ m, 0.01 ⁇ m to 0.03 ⁇ m, or It may be 0.01 ⁇ m to 0.03 ⁇ m.
  • the maximum height roughness (R max ) of the polyester-based film is 1.5 ⁇ m or less.
  • the maximum height roughness (R max ) of the polyester film may be 1.4 ⁇ m or less, 1.3 ⁇ m or less, 1.1 ⁇ m or less, or 1.0 ⁇ m or less, 0.1 ⁇ m to 1.5 ⁇ m, 0.2 ⁇ m to 1.4 ⁇ m, or 0.5 ⁇ m. to 1.3 ⁇ m, 0.6 ⁇ m to 1.1 ⁇ m, or 0.7 ⁇ m to 1.0 ⁇ m.
  • the surface roughness is controlled to a desirable range to wind and run the film.
  • Processability such as performance, can be improved, and surface properties can be improved at the same time without deteriorating mechanical properties and optical properties.
  • Surface roughness such as the 10-point average roughness (R z ), center line average roughness (R a ), and maximum height roughness (R max ) may be measured using a two-dimensional contact surface roughness meter (SE3300 manufactured by Kosaka).
  • the 10-point average roughness (R z ) is surface roughness according to KS B 0161.
  • R z the 10-point average roughness
  • the center line average roughness (R a ) is a surface roughness according to KS B 0161, and a straight line generated when a mountain is cut from a roughness curve to fill a valley is called a center line, and a measured length is taken in the direction of the center line, and from the center line It can be calculated by dividing the area of the upper part obtained by folding the lower part upwards by the measured length.
  • the maximum height roughness (R max ) is a surface roughness according to KS B 0161, a reference length is taken from a cross-sectional curve, and it is parallel to the center line of the cross-sectional curve and the highest peak and the deepest valley. Can be calculated as the distance between two parallel lines. there is.
  • the polyester-based film may have an RF of 0.8 or less according to Equation 2.
  • R max is the maximum height roughness ( ⁇ m) of the polyester-based film
  • F d is the kinetic friction coefficient of the polyester-based film.
  • the RF represents the ratio between the surface properties of the polyester-based film
  • the RF may be 0.75 or less, 0.7 or less, 0.65 or less, 0.6 or less, or 0.55 or less, 0.05 to 0.8, 0.05 to 0.8, 0.08 to 0.7 , 0.1 to 0.65, 0.15 to 0.6, 0.2 to 0.6 or 0.3 to 0.55.
  • the RF value satisfies the above range, surface roughness can be controlled to a more preferable range to simultaneously improve mechanical properties and optical properties, and in particular, transparency can be maximized by reducing haze.
  • the polyester-based film may have a dynamic coefficient of friction (F d ) of 0.6 or less, and a static coefficient of friction (F s ) of 0.75 or less.
  • the surface dynamic friction coefficient (F d ) of the film may be 0.5 or less or 0.55 or less
  • the surface static friction coefficient (F s ) of the film may be 0.74 or less, 0.73 or less, 0.7 or less, or 0.68 or less.
  • both mechanical properties and optical properties can be improved.
  • the surface roughness and the surface friction coefficient are not exactly proportional, and when the surface roughness and the surface friction coefficient satisfy the above ranges, respectively, haze can be reduced without deterioration of mechanical properties, thereby maximizing transparency.
  • Haze of the polyester film may be 8% or less.
  • the haze of the polyester film may be 8% or less, 6% or less, 5% or less, or 4.5% or less.
  • the polyester-based film according to the embodiment has excellent transparency while having excellent mechanical properties by having a haze that satisfies the above range while including a filler.
  • the transmittance of the polyester-based film may be 88% or more at a wavelength of 400 nm to 700 nm.
  • the transmittance of the polyester film at a wavelength of 400 nm to 700 nm may be 88.5% or more, 89% or more, or 89.5% or more.
  • Tensile strength of the polyester film may be 19 kgf/mm 2 or less.
  • the tensile strength of the in-plane first direction of the polyester film may be 19 kgf/mm 2 or less, 18 kgf/mm 2 or less, 16 kgf/mm 2 or less, or 15 kgf/mm 2 or less, and 10 kgf/mm 2 or less.
  • mm 2 to 19 kgf/mm 2 10 kgf/mm 2 to 16 kgf/mm 2 or 10 kgf/mm 2 to 15 kgf/mm 2 .
  • the tensile strength in the second direction perpendicular to the first direction in the plane of the polyester film may be 19 kgf/mm 2 or less or 18.5 kgf/mm 2 or less, 10 kgf/mm 2 to 19 kgf/mm 2 , 12 kgf/mm 2 to 19 kgf/mm 2 , 13 kgf/mm 2 to 18.5 kgf/mm 2 or 14.5 kgf/mm 2 to 18.5 kgf/mm 2 .
  • the polyester-based film When the tensile strength of the polyester-based film satisfies the above range, it can be used in a variety of ways, such as for metal replacement, electronic boards or display devices, and can be more advantageous in implementing weight reduction due to excellent mechanical properties.
  • the first direction may be a width direction (TD) or a length direction (MD).
  • the first direction may be a length direction (MD)
  • the second direction perpendicular to the first direction may be a width direction (TD).
  • the elongation at break of the polyester-based film may be 30% or more.
  • the elongation at break in the first in-plane direction of the polyester-based film may be 30% or more, 35% or more, 40% or more, or 42% or more, and the second in-plane direction perpendicular to the first direction of the polyester-based film
  • the elongation at break in the direction may be 30% or more, 32% or more, or 34% or more.
  • the polyester film When the elongation at break of the polyester film satisfies the above range, it can be used in a variety of ways for metal replacement, electronic boards or display devices due to its excellent mechanical properties, and can be more advantageous in implementing weight reduction.
  • Modulus of the polyester-based film may be 320 kgf/mm 2 or less. Specifically, the modulus of the polyester-based film in the first direction in the plane is 320 kgf/mm 2 or less, 310 kgf/mm 2 or less, 300 kgf/mm 2 or less, 290 kgf/mm 2 or less, or 288 kgf/mm 2 or less.
  • the modulus of the polyester film in the second direction perpendicular to the first in-plane direction is 320 kgf/mm 2 or less, 310 kgf/mm 2 or less, 305 kgf/mm 2 or less, 300 kgf/mm 2 or less, or 299 kgf/mm 2 or less, 230 kgf/mm 2 to 320 kgf/mm 2 , 260 kgf/mm 2 to 310 kgf/mm 2 , 275 kgf/mm 2 to 320 kgf/mm 2 , 275 kgf/mm 2 to 300 kgf/mm 2 or 280 kgf/mm 2 to 299 kgf/mm 2 .
  • the tensile strength, elongation at break and modulus may be measured at room temperature according to ASTM D 882 by using a universal testing machine (4206-001, manufactured by INSTRON).
  • the polyester-based film may have a thickness of 1 ⁇ m to 500 ⁇ m, 5 to 250 ⁇ m, 10 to 150 ⁇ m, 10 ⁇ m to 100 ⁇ m, 10 ⁇ m to 80 ⁇ m, or 30 ⁇ m to 60 ⁇ m.
  • the polyester-based film includes a co-polyester-based resin in which a diol and two or more kinds of dicarboxylic acids are copolymerized.
  • the diol includes cyclohexanedimethanol or a derivative thereof.
  • the diol may include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol or 1,4-cyclohexanedimethanol, preferably 1,4-cyclohexanedimethanol can include More specifically, the diol may include 1,4-cyclohexanedimethanol or a derivative thereof.
  • the diol may include 70 mol% or more of cyclohexanedimethanol or a derivative thereof.
  • the copolyester-based resin contains cyclohexanedimethanol or a derivative thereof in an amount of 72 mol% or more, 75 mol% or more, 85 mol% or more, 88 mol% or more, or 90 mol% based on the total number of moles of the diol. or more, 93 mol% or more, 95 mol% or more, 97 mol% or more, 99 mol% or more, or 100 mol%.
  • Flexibility, durability, and hydrolysis resistance can be improved by including cyclohexanedimethanol or a derivative thereof in the diol, and durability, heat resistance, and hydrolysis resistance can be maximized when the diol is composed of only cyclohexanedimethanol. .
  • the diol may include at least one selected from the group consisting of ethylene glycol, neopentyl glycol, and diethylene glycol, if necessary.
  • the copolymerized polyester-based resin contains 1 mol% to 30 mol%, 1 mol% to 1 mol% of at least one selected from the group consisting of ethylene glycol, neopentyl glycol and diethylene glycol based on the total number of moles of the diol. 20 mol%, 1 mol% to 15 mol%, 1 mol% to 10 mol%, or 1 mol% to 5 mol%.
  • the dicarboxylic acid may include two or more dicarboxylic acids.
  • the dicarboxylic acid may include a first dicarboxylic acid and a second dicarboxylic acid, the first dicarboxylic acid may be terephthalic acid, and the second dicarboxylic acid may be isophthalic acid. there is.
  • the dicarboxylic acid may include 70 mol% to 99 mol% of terephthalic acid and 1 mol% to 30 mol% of isophthalic acid.
  • the copolyester-based resin contains 73 mol% to 99 mol%, 75 mol% to 99 mol%, 80 mol% to 98 mol%, 83 mol% of terephthalic acid based on the total number of moles of the dicarboxylic acid.
  • % to 98 mol% or 85 mol% to 98 mol% or 1 mol% to 28 mol%, 1 mol% to 25 mol%, 1 mol% to 20 mol%, 2 mol% to 2 mol% isophthalic acid 15 mol%, 3 mol% to 13 mol%, 3 mol% to 10 mol%, or 3 mol% to 8 mol%.
  • contents of terephthalic acid and isophthalic acid satisfy the above ranges, flexibility, durability, heat resistance and hydrolysis resistance may be improved.
  • the co-polyester-based resin may include an additional dicarboxylic acid other than the first and second dicarboxylic acids.
  • the additional dicarboxylic acid may include dimethyl terephthalic acid, and for example, the co-polyester-based resin is present in an amount of 1 mol% to 15 mol%, 1 mol% to 10 mol% based on the total number of moles of the dicarboxylic acid. Or 3 mol% to 7 mol% of dimethyl terephthalic acid may be further included.
  • the co-polyester-based resin according to the embodiment may include a polycyclohexylenedimethylene terephthalate (PCT) resin.
  • PCT polycyclohexylenedimethylene terephthalate
  • the copolymerized polyester-based resin includes polycyclohexylenedimethylene terephthalate (PCT) resin, it has excellent heat resistance and chemical resistance compared to polyethylene terephthalate (PET) resin and polybutylene terephthalate (PBT) resin. and hygroscopicity. Therefore, mechanical properties such as tensile strength and modulus may be improved while crystallinity increases due to excellent crystallization characteristics during the manufacturing process through melt extrusion, stretching, etc. at a high temperature.
  • PCT polycyclohexylenedimethylene terephthalate
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • the copolyester-based resin contains 1 mol% to 30 mol% of isophthalic acid as dicarboxylic acid, it may be excessively high as cyclohexylenedimethylene is included. It is more advantageous to increase the handleability of the polymer by lowering the melting point (Tm) while lowering the possible crystallization rate.
  • the polyester-based film may include 85% by weight or more of the co-polyester-based resin.
  • the content of the co-polyester-based resin is 88% by weight or more, 90% by weight or more, 93% by weight or more, 95% by weight or more, 98% by weight or more, 99% by weight or more based on the total weight of the polyester-based film. % or more than 100%, 85% to 100%, 90% to 100%, 95% to 100% or 98% to 100%.
  • the co-polyester-based resin may further include at least one additive selected from the group consisting of an ultraviolet stabilizer, a heat stabilizer, an antioxidant, and an inert particle.
  • the UV stabilizer may be at least one selected from the group consisting of benzophenone-based, benzotriazole-based, cyanoacrylate-based, and salicylic acid ester-based compounds
  • the heat stabilizer may be an iodine-based compound
  • the antioxidant may be a phosphorus-based antioxidant, a phenol-based antioxidant, or a sulfur-based antioxidant
  • the inert particle may be silica or potassium carbonate, but is not limited thereto.
  • the content of the additive is 0.5% to 15% by weight, 1% to 13% by weight, 1.2% to 12% by weight, 1.5% to 10% by weight, 1.7% by weight based on the total weight of the co-polyester-based resin. % to 8% or 1.8% to 7.5%.
  • the polyester-based film may include a filler.
  • the polyester film according to the embodiment has a 10-point average roughness (R z ), center line average roughness (R a ) and maximum height roughness (R max ) of the polyester film according to the type, physical properties and content of the filler. ), as well as mechanical properties such as friction coefficient, tensile strength, elongation at break and modulus, and optical properties such as haze and light transmittance may vary.
  • the polyester-based film by including the filler, controls the surface roughness to a desirable range and has excellent optical properties, particularly low haze, and excellent transparency without deteriorating mechanical properties.
  • the surface roughness characteristics and optical characteristics of the film may be significantly different depending on the particle size, shape, and physical properties of the filler.
  • the filler may include at least one selected from the group consisting of titanium dioxide, barium sulfate, calcium carbonate, magnesium carbonate, zinc carbonate, zinc oxide, magnesium oxide, alumina, and silica. Specifically, when the filler includes silica, it may be preferable in terms of optical properties, but is not limited thereto.
  • the filler may be spherical having a spherical shape.
  • the polyester film can further improve dispersibility and control the surface roughness more effectively, as compared to the case of including a bulky filler in the form of a lump. may have characteristics.
  • the filler may include spherical silica beads, and when the filler includes spherical silica beads, surface roughness can be more effectively controlled and haze can be reduced to maximize transparency.
  • the average particle diameter (D sem ) of the filler may be 0.01 ⁇ m to 2.0 ⁇ m.
  • the average particle diameter (D sem ) of the filler is 0.01 ⁇ m to 1.9 ⁇ m, 0.01 ⁇ m to 1.8 ⁇ m, 0.02 ⁇ m to 1.3 ⁇ m, 0.03 ⁇ m to 1.0 ⁇ m, 0.05 ⁇ m to 0.8 ⁇ m, 0.1 ⁇ m to 0.5 ⁇ m, or It may be 0.15 ⁇ m to 0.4 ⁇ m.
  • polyester-based films have limitations in mechanical properties such as tensile strength, elongation at break, and modulus that can be improved by adjusting process conditions such as stretching temperature, elongation rate, and heat setting temperature.
  • the polyester-based film according to the embodiment may further improve mechanical properties such as tensile strength, elongation at break and modulus without additional process cost by maintaining existing process conditions by including a filler having an average particle diameter satisfying the above range. there is.
  • the D 10 of the filler may be 0.05 ⁇ m to 0.5 ⁇ m.
  • the D 10 of the filler may be 0.05 ⁇ m to 0.45 ⁇ m, 0.1 ⁇ m to 0.4 ⁇ m, 0.13 ⁇ m to 0.36 ⁇ m, 0.18 ⁇ m to 0.33 ⁇ m, 0.2 ⁇ m to 0.31 ⁇ m, or 0.21 ⁇ m to 0.28 ⁇ m.
  • D 50 of the filler may be 0.12 ⁇ m to 0.65 ⁇ m.
  • the D 50 of the filler may be 0.14 ⁇ m to 0.55 ⁇ m, 0.16 ⁇ m to 0.5 ⁇ m, 0.18 ⁇ m to 0.35 ⁇ m, 0.22 ⁇ m to 0.32 ⁇ m, or 0.25 ⁇ m to 0.3 ⁇ m.
  • D 90 of the filler may be 0.25 ⁇ m to 0.75 ⁇ m.
  • the D 90 of the filler may be 0.26 ⁇ m to 0.65 ⁇ m, 0.28 ⁇ m to 0.58 ⁇ m, 0.31 ⁇ m to 0.52 ⁇ m, 0.35 ⁇ m to 0.48 ⁇ m, or 0.36 ⁇ m to 0.46 ⁇ m.
  • the particle diameter of the filler may be measured by a laser diffraction particle size distribution measurement method, for example, a wet laser diffraction particle size distribution measurement method.
  • 0.3 g of the filler is mixed with 30 ml of isopropyl alcohol and ultrasonicated for 5 minutes at a power of 45 W to prepare a dispersion, and the particle size distribution of the filler in the dispersion may be measured with a particle size distribution analyzer.
  • the cumulative 50% particle size based on the volume was indicated as D 50 .
  • the polyester film may include the filler in an amount of 500 ppm to 2,000 ppm.
  • the content of the filler may be 550 ppm to 2,000 ppm, 600 ppm to 2,000 ppm, 700 ppm to 1,500 ppm, or 800 ppm to 1,300 ppm based on the total weight of the polyester film.
  • a method for manufacturing a polyester-based film includes preparing a resin composition by mixing a co-polyester-based resin in which diols and dicarboxylic acids are copolymerized with a filler; Melting and extruding the resin composition to prepare an unstretched sheet; preparing a stretched sheet by first stretching the unstretched sheet in a first direction and secondarily stretching the unstretched sheet in a second direction perpendicular to the first direction; and preparing a polyester-based film by heat-setting the stretched sheet at 200° C. to 260° C., wherein the polyester-based film has an R d of 2.5 or less according to Formula 1.
  • a resin composition is prepared by mixing a co-polyester-based resin in which diols and dicarboxylic acids are copolymerized with a filler .
  • the co-polyester-based resin may be formed by polymerization after a diol and a dicarboxylic acid undergo transesterification. Descriptions of the diol, dicarboxylic acid, and co-polyester-based resin are as described above.
  • a copolymerized polyester-based resin may be prepared by mixing a diol and a dicarboxylic acid, performing an ester exchange reaction by introducing a transesterification catalyst, and then proceeding with a polymerization reaction.
  • the catalyst for the transesterification reaction may be at least one selected from the group consisting of manganese acetate tetrahydrate, calcium acetate, and zinc acetate.
  • the amount of the transesterification catalyst may be 0.02 part by weight to 0.2 part by weight, 0.02 part by weight to 0.1 part by weight, or 0.05 part by weight to 0.1 part by weight based on the total weight of the dicarboxylic acid.
  • stabilizers such as trimethylphosphate
  • titanium such as titanium isopropoxide, tetrapropyl titanate, tetrabutyl titanate or tetraisopropyl titanate, germanium oxide, germanium methoxide, germanium ethoxide, tetramethyl germanium, te
  • the content of the polymerization catalyst may be 0.00001 wt % to 0.001 wt % or 0.00005 wt % to 0.0005 wt % based on the total weight of the co-polyester resin.
  • a resin composition may be prepared by adding and mixing a filler to the co-polyester-based resin prepared above. Description of the filler is as described above.
  • the step of preparing the resin composition may include the step of first mixing the co-polyester-based resin and the filler, and the step of secondarily mixing the first mixture with a base resin. .
  • the quality of the polyester film produced by first mixing the co-polyester-based resin and the filler and additionally using a raw resin having the same components and contents as the co-polyester-based resin can be further improved.
  • the raw material resin may include a diol and a dicarboxylic acid.
  • the diol and dicarboxylic acid of the raw resin may have the same type and content as the diol and dicarboxylic acid of the co-polyester-based resin.
  • the quality of the produced polyester-based film can be further improved.
  • the content of the co-polyester-based resin added in the first mixing step may be 95% by weight or more or 97% by weight or more, 95% to 99.5% by weight, 95% to 99% by weight or 97% by weight. % to 99% by weight.
  • the content of the filler added in the mixing step may be 5% by weight or less, 4% by weight or less, or 3% by weight or less, 0.5% to 5% by weight, 0.5% to 4% by weight, or 1% to 3% by weight. weight percent.
  • the first mixture may be mixed in an amount of 1 part by weight to 10 parts by weight.
  • 1 part by weight to 10 parts by weight, 1 part by weight to 8 parts by weight, 1.5 parts by weight to 6 parts by weight, or 2 parts by weight to 5 parts by weight may be introduced and mixed.
  • the resin composition is melt-extruded to prepare an unstretched sheet .
  • cooling may be performed to prepare an unstretched sheet.
  • the melt-extruding step may be performed at a temperature of Tm+5°C to Tm+70°C, Tm+5°C to Tm+50°C or Tm+7°C to Tm+35°C, and the cooling step is Tg-120°C. to Tg+20°C, Tg-110°C to Tg+10°C, Tg-105°C to Tg-30°C, Tg-105°C to Tg-50°C, Tg-105°C to Tg-65°C, Tg-105°C to Tg-80 °C.
  • the melt extrusion temperature may be 260 ° C to 320 ° C, 270 ° C to 310 ° C or 270 ° C to 295 ° C
  • the cooling temperature may be -20 ° C to 100 ° C, 0 ° C to 90 ° C, 5 ° C to 75°C, 10°C to 60°C, 10°C to 50°C or 15°C to 45°C.
  • the melt-extrusion temperature satisfies the above range, the viscosity of the extrudate may be appropriately maintained while melting is smooth.
  • a stretched sheet is prepared by first stretching the unstretched sheet in a first direction and secondarily stretching it in a second direction perpendicular to the first direction.
  • the primary stretching may be performed at a stretching rate of 2 to 5 times at a temperature of 60° C. to 120° C.
  • the first stretching step is 2 to 5 times, 2.5 times at a temperature of 60 ° C to 120 ° C, 70 ° C to 110 ° C, 75 ° C to 105 ° C, 80 ° C to 100 ° C or 85 ° C to 100 ° C. to 4.5 times, 2.5 times to 4 times, or 2.9 times to 3.5 times.
  • the temperature and elongation rate of the primary stretching satisfy the above ranges, heat resistance, durability and hydrolysis resistance can be improved.
  • secondary stretching is performed in a second direction perpendicular to the first direction.
  • the secondary stretching may be performed at a stretching rate of 2 to 5 times.
  • the secondary stretching is 2 to 5 times, 2.5 times to 2.5 times at a temperature of 70 °C to 140 °C, 80 °C to 140 °C, 90 °C to 135 °C, 100 °C to 130 °C or 115 °C to 125 °C. It may be performed at a stretch rate of 5x, 3x to 4.5x or 3.5x to 4.5x.
  • a preheating step or a coating step may be additionally performed before the second stretching.
  • the preheating step may be performed at 70 °C to 120 °C for 0.01 to 1 minute.
  • the preheating temperature may be 70°C to 120°C, 75°C to 115°C, or 80°C to 110°C
  • the preheating time may be 0.01 to 1 minute, 0.05 minutes to 0.5 minutes, or 0.08 minutes to 0.2 minutes. there is.
  • the coating step is a step capable of imparting functionality such as antistatic to the polyester film, and may be performed by spin coating or in-line coating, but is not limited thereto.
  • a ratio (d1/d2) of the stretching ratio d1 in the first direction and the stretching ratio d2 in the second direction may be 0.5 to 1.
  • the ratio (d1/d2) of the stretching ratio d1 in the first direction and the stretching ratio d2 in the second direction may be 0.5 to 0.95, 0.65 to 0.95, or 0.7 to 0.9.
  • the stretched sheet is heat-set at 200° C. to 260° C. to prepare a polyester-based film .
  • the heat setting may be annealing, and may be performed at 200° C. to 260° C. for 0.01 minute to 1 minute.
  • the heat setting temperature may be 200 ° C to 260 ° C, 210 ° C to 250 ° C, 225 ° C to 250 ° C, or 235 ° C to 245 ° C
  • the heat setting time is 0.05 to 0.5 minutes or 0.08 minutes to 0.08 minutes. It may be 0.2 minutes, but is not limited thereto.
  • a step of relaxing the heat-set sheet in a first direction or in a second direction perpendicular to the first direction may be further performed.
  • the heat-set sheet is firstly relaxed in a first direction and then secondarily relaxed in a second direction, or the heat-set sheet is firstly relaxed in a second direction and then the first direction
  • a second relaxation step may be additionally performed.
  • the heat-set sheet may be first relaxed in the TD direction and then secondarily relaxed in the MD direction.
  • the relaxation step is 0.5% to 5%, 0.8% at a temperature of 100 ° C to 180 ° C or 110 ° C to 175 ° C. % to 4% or 0.8% to 3.5% relaxation rate.
  • the first relaxation may be performed at an elongation rate of 1% to 10% in the second direction
  • the second relaxation may be performed at an elongation rate of 0.5% or more to less than 2% in the first direction.
  • the first relaxation step may be performed at a relaxation rate of 0.5% or more to less than 2% at a temperature of 150 ° C to 200 ° C
  • the second relaxation step may be performed at a relaxation rate of 0.5% to 5% at a temperature of 110°C to 190°C.
  • the first relaxation step is 1% to 10%, 1% to 9%, 1.5% at a temperature of 150 ° C to 200 ° C, 155 ° C to 200 ° C, 160 ° C to 180 ° C or 165 ° C to 175 ° C. to 8%, 1.5% to 7%, 2% to 6%, or 2% to 5% relaxation rate
  • the second relaxation step is 110°C to 190°C, 110°C to 180°C, 110°C 0.5% to less than 2%, 0.5% to 1.95%, 0.7% to 1.8% or 0.9% to 1.6% at a temperature of from 170 ° C, 115 ° C to 150 ° C, 115 ° C to 140 ° C or 115 ° C to 130 ° C. It can be done with a relaxation rate.
  • the first relaxation rate: the second relaxation rate may be 1:0.1 to 1.0.
  • the first relaxation rate: the second relaxation rate may be 1:0.1 to 0.9, 1:0.1 to 0.8, 1:0.2 to 0.7, or 1:0.25 to 0.65.
  • the second relaxation step may be performed in two or more sections, and the second relaxation rate may be the total sum of the relaxation rates of each section.
  • the second relaxation rate is 2 %am.
  • the transport speed of the film in the second relaxation step may be 1% to 10% slower than the transport speed of the film in the first relaxation step.
  • the transport speed of the film in the secondary relaxation step may be 2% to 10% or 2% to 8% slower than the transport speed of the film in the first relaxation step.
  • tetrabutyl titanate based on 100 parts by weight of the dicarboxylic acid was added as a polymerization catalyst and stirred for 10 minutes. Thereafter, the reactants were transferred to a separate reactor equipped with a vacuum facility, and a polymerization reaction was performed at 300 ° C. for 180 minutes to prepare a copolymerized polyester-based resin (polycyclohexanedimethylene terephthalate (PCT) resin).
  • PCT polycyclohexanedimethylene terephthalate
  • a resin composition was prepared by secondarily mixing 4 parts by weight of the primary mixture with 96 parts by weight of a base resin.
  • the raw material resin contained 100 mol% of cyclohexanedimethanol (CHDM) as a diol, and 96 mol% of terephthalic acid (TPA) and 4 mol% of isophthalic acid (IPA) as dicarboxylic acids.
  • the content of the silica beads in the resin composition prepared by the secondary mixing was 1,000 ppm.
  • a resin composition was prepared in the same manner as in Preparation Example 2-1, except that blocky silica beads (D sem : 3.5 ⁇ m) were used.
  • a polyester-based film was prepared in the same manner as in Example 1, except that process conditions were applied as shown in Table 1 below.
  • Example 1 Preparation Example 2-1 3.0 4.0 90 120 240
  • Example 2 Preparation Example 2-1 3.2 3.9 90 120 240
  • Example 3 Preparation Example 2-1 3.4 4.0 90 120 240 Comparative Example 1 Preparation Example 2-2 3.0 3.9 90 120 240 Comparative Example 2
  • the 10-point average roughness (R z ) is a surface roughness according to KS B 0161, and when the surface is first cut with a plane perpendicular to the surface of the film, a section appearing on the cut surface is enlarged and recorded by a reference length in the cross-sectional curve was collected, and an arbitrary straight line parallel to the average line of the cross-sectional curve was set as the reference line. At this time, the difference between the average value of the distance from the baseline for the five highest peaks and the average value for the distance from the baseline for the five lowest valleys was calculated.
  • the center line average roughness (R a ) is a surface roughness according to KS B 0161, and a straight line generated when a mountain is cut from a roughness curve to fill a valley is called a center line, and a measured length is taken in the direction of the center line, and from the center line It was calculated by dividing the area of the upper part obtained by folding the lower part upward by the measured length.
  • the maximum height roughness (R max ) is a surface roughness according to KS B 0161, a reference length is taken from a cross-sectional curve, and the distance between two parallel lines that are parallel to the center line of the cross-sectional curve and touch the highest peak and the deepest valley was calculated. .
  • R d was calculated according to Equation 1 below.
  • R max is the maximum height roughness ( ⁇ m) of the polyester-based film
  • R a is the center line average roughness ( ⁇ m) of the polyester-based film.
  • R max is the maximum height roughness ( ⁇ m) of the polyester-based film
  • F d is the kinetic friction coefficient of the polyester-based film.
  • Samples were prepared by cutting the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 into a size of 150 mm in width and 100 mm in length, and in accordance with ASTM D 882, an INSTRON universal testing machine (4206 -001, manufacturer: UTM) at a test speed of 200 mm/min, the tensile strength was measured three times for the same sample, and the average value was calculated.
  • Samples were prepared by cutting the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 into a size of 150 mm in width and 100 mm in length, and in accordance with ASTM D 882, an INSTRON universal testing machine (4206 -001, manufacturer: UTM) at a test speed of 200 mm/min, the elongation at break was measured three times for the same sample, and the average value was calculated.
  • ASTM D 882 an INSTRON universal testing machine (4206 -001, manufacturer: UTM) at a test speed of 200 mm/min
  • Modulus of the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was measured according to KS B 5521.
  • the haze of the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was measured using a haze meter (SEP-H, manufactured by Nihon Semitsu Kogaku).
  • the light transmittance at 380 nm was measured using UltraScan PRO (manufacturer: Hunterlab).
  • FIGS. 1 to 3 show scanning electron microscope (SEM) images of the polyester films of Examples 1 to 3
  • FIGS. 4 to 6 are scanning electron microscope images of the polyester films of Comparative Examples 1 to 3 ( SEM) images are shown.
  • polyester films of Examples 1 to 3 had better dispersibility than the films of Comparative Examples 1 to 3, so that the surface roughness was effectively controlled while having excellent surface properties.
  • polyester films of Examples 1 to 3 exhibited superior optical properties and mechanical properties compared to the films of Comparative Examples 1 to 3.
  • the 10-point average roughness (R z ), the center line average roughness (R a ), and the maximum height roughness (R max ) are all controlled within a specific range, thereby increasing the friction coefficient and tensile strength.
  • optical properties such as haze and light transmittance were all excellent without degradation of mechanical properties such as elongation at break and modulus.
  • the 10-point average roughness (R z ), the center line average roughness (R a ), and the maximum height roughness (R max ) do not satisfy desirable ranges, and thus have poor optical properties such as haze and light transmittance. has been lowered

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Abstract

One embodiment relates to: a polyester-based film which comprises a filler and a copolymerized polyester-based resin formed by copolymerizing a diol and a dicarboxylic acid, and which has a Rd, according to formula 1 for centerline average roughness (Ra) and maximum height roughness (Rmax), of at most 2.5; and a production method therefor. The polyester-based film comprises a specific filler, and thus the surface roughness of the polyester-based film may be controlled, and accordingly, processability, including winding and running performance, is improved, and also, mechanical and optical properties are improved, and thus the polyester-based film has excellent quality.

Description

폴리에스테르계 필름 및 이의 제조 방법Polyester-based film and manufacturing method thereof
구현예는 폴리에스테르계 필름 및 이의 제조 방법에 관한 것이다.Embodiments relate to a polyester-based film and a method for producing the same.
전자기기에서 필수 부품인 회로기판 등의 전자기판은 절연성 기재 필름에 도전 패턴이 형성된 것으로, 특히 휴대폰이나 태블릿 PC와 같은 스마트 기기에 장착되는 연성회로기판(Flexible Printed Circuit Board, FPCB)이 대표적이다. 최근 이러한 스마트 기기의 성장에 따라 전자 제품의 박형화, 경량화, 유연화 및 고성능화의 요구가 증가하면서, 연성회로기판의 주요 소재인 연성동박적층체(Flexible Copper Clad Laminate, FCCL)의 성능을 향상시킬 수 있는 연구가 계속되고 있다.Electronic boards, such as circuit boards, which are essential components in electronic devices, have conductive patterns formed on insulating base films, and in particular, flexible printed circuit boards (FPCB) mounted on smart devices such as mobile phones and tablet PCs are representative. Recently, as the demand for thinning, lightening, flexibility, and high performance of electronic products increases with the growth of these smart devices, the performance of Flexible Copper Clad Laminate (FCCL), the main material of flexible circuit boards, can be improved. Research is ongoing.
연성동박적층체는 일반적으로 기재 필름의 일면 또는 양면에 동박을 적층하여 제조되는데, 종래에는 두께가 얇으면서 우수한 물성과 성형성을 갖는 액정 결정성 폴리머(Liquid Crystal Polymer, LCP)나 폴리이미드계 수지가 기재 필름으로 사용되었다. 그러나, 이러한 액정 결정성 폴리머나 폴리이미드계 수지는 단가 및 유전율이 높고 내습성이 낮은 문제가 있다.Flexible copper clad laminates are generally manufactured by laminating copper foil on one side or both sides of a base film. was used as a base film. However, such liquid crystal crystalline polymers or polyimide-based resins have problems in that they have high unit price and high permittivity and low moisture resistance.
한편, 폴리에스테르계 수지는 내구성, 내약품성, 내열성과 같은 기계적 물성이나 투명성과 같은 광학적 특성도 우수하므로, 섬유, 필름, 성형품 등의 재료뿐만 아니라, 디스플레이 기기와 같은 여러 산업용 재료로 널리 사용되고 있다. 그러나, 이러한 폴리에스테르계 수지를 이용하여 제조된 폴리에스테르계 필름은 내열성 및 내가수분해성은 우수하나, 소프트하고 높은 표면 마찰계수로 인하여 권취 등의 공정시 어려움이 있고 주행 성능이 좋지 않은 문제가 있다.On the other hand, since polyester-based resins are excellent in mechanical properties such as durability, chemical resistance, heat resistance, and optical properties such as transparency, they are widely used as various industrial materials such as display devices as well as materials such as fibers, films, and molded products. However, polyester-based films manufactured using such polyester-based resins have excellent heat resistance and hydrolysis resistance, but have difficulties in processes such as winding due to soft and high surface friction coefficients, and poor driving performance. .
이러한 문제를 해결하기 위해 필름의 표면에 프라이머 코팅을 하거나 폴리에스테르계 수지에 다양한 첨가제를 투입하는 등의 시도가 있었으나, 폴리에스테르계 필름의 기계적 물성이나 광학적 특성을 저하시키지 않으면서 동시에 권취 등의 공정성도 향상시키는데 한계가 있다. 따라서, 기계적 물성 및 광학적 특성은 물론, 권취 및 주행 성능과 같은 공정성도 우수한 폴리에스테르계 필름에 대한 연구가 계속되고 있다.In order to solve this problem, attempts have been made such as primer coating on the surface of the film or injecting various additives into the polyester resin, but at the same time, fairness such as winding without degrading the mechanical properties or optical properties of the polyester film There is also a limit to improvement. Therefore, research on a polyester-based film having excellent processability such as winding and running performance as well as mechanical and optical properties is being continued.
일례로, 한국 공개특허 제2006-0060082호는 폴리이미드 필름의 표면을 개질하여 동박에 적용한 연성동박적층 필름을 개시하고 있으나, 이러한 폴리이미드 필름은 단가 및 유전율이 높고 내습성이 낮아 연성동박적층 필름의 성능 향상에 한계가 있으며, 상기 개질 단계에서 필름을 용액에 침지하므로 내습성이 더욱 저하될 수 있다. For example, Korean Patent Publication No. 2006-0060082 discloses a flexible copper-clad laminate film in which the surface of a polyimide film is modified and applied to copper foil, but such a polyimide film has a high unit price and high permittivity and low moisture resistance. There is a limit to performance improvement, and since the film is immersed in a solution in the reforming step, moisture resistance may be further deteriorated.
[선행기술문헌][Prior art literature]
[특허문헌][Patent Literature]
(특허문헌 1) 한국 공개특허 제2006-0060082호(Patent Document 1) Korean Patent Publication No. 2006-0060082
따라서, 구현예는 권취 및 주행 성능과 같은 공정성은 물론, 기계적 물성 및 광학적 특성도 우수한 폴리에스테르계 필름 및 이의 제조 방법을 제공하고자 한다.Accordingly, embodiments are intended to provide a polyester-based film and a method for manufacturing the same, which are excellent in processability such as winding and running performance, as well as mechanical properties and optical properties.
일 구현예에 따른 폴리에스테르계 필름은 디올 및 2종 이상의 디카르복실산이 공중합된 공중합 폴리에스테르계 수지; 및 필러를 포함하고, 하기 식 1에 따른 Rd가 2.5 이하이다. A polyester-based film according to an embodiment includes a co-polyester-based resin in which a diol and two or more dicarboxylic acids are copolymerized; and a filler, and R d according to Equation 1 below is 2.5 or less.
[식 1][Equation 1]
Figure PCTKR2022015165-appb-img-000001
Figure PCTKR2022015165-appb-img-000001
상기 식 1에 있어서,In the above formula 1,
Rmax는 폴리에스테르계 필름의 최대 높이 거칠기(㎛)이고, R max is the maximum height roughness (μm) of the polyester film,
Ra는 폴리에스테르계 필름의 중심선 평균 거칠기(㎛)이다.R a is the center line average roughness (μm) of the polyester-based film.
다른 구현예에 따른 폴리에스테르계 필름의 제조 방법은 디올 및 디카르복실산이 공중합된 공중합 폴리에스테르계 수지와 필러를 혼합하여 수지 조성물을 제조하는 단계; 상기 수지 조성물을 용융압출하여 미연신 시트를 제조하는 단계; 상기 미연신 시트를 제 1 방향으로 1차 연신하고, 상기 제 1 방향과 수직한 제 2 방향으로 2차 연신하여 연신 시트를 제조하는 단계; 및 상기 연신 시트를 200℃ 내지 260℃에서 열고정하여 폴리에스테르계 필름을 제조하는 단계를 포함하고, 상기 폴리에스테르계 필름이 상기 식 1에 따른 Rd가 2.5 이하이다.A method for manufacturing a polyester-based film according to another embodiment includes preparing a resin composition by mixing a co-polyester-based resin in which diols and dicarboxylic acids are copolymerized with a filler; Melting and extruding the resin composition to prepare an unstretched sheet; preparing a stretched sheet by first stretching the unstretched sheet in a first direction and secondarily stretching the unstretched sheet in a second direction perpendicular to the first direction; and preparing a polyester-based film by heat-setting the stretched sheet at 200° C. to 260° C., wherein the polyester-based film has an R d of 2.5 or less according to Formula 1.
구현예에 따른 폴리에스테르계 필름은 특정 필러를 포함함으로써, 표면조도를 조절하여 필름의 권취 및 주행 성능 등의 공정성이 우수할 뿐만 아니라, 우수한 기계적 물성 및 광학적 특성을 갖는다. By including a specific filler, the polyester-based film according to the embodiment has excellent processability such as winding and running performance of the film by controlling the surface roughness, as well as excellent mechanical properties and optical properties.
특히, 상기 폴리에스테르계 필름은 10점 평균 거칠기(Rz), 중심선 평균 거칠기(Ra) 및 최대 높이 거칠기(Rmax)가 모두 바람직한 범위를 만족하면서 분산성 또한 우수하여, 기계적 물성 및 광학적 특성을 저하시키기 않으면서 동시에 표면 특성도 향상시킬 수 있다.In particular, the polyester-based film has excellent dispersibility while satisfying 10-point average roughness (R z ), center line average roughness (R a ), and maximum height roughness (R max ) within preferred ranges, thereby providing mechanical properties and optical properties. It is possible to improve the surface properties at the same time without degrading.
도 1은 실시예 1의 폴리에스테르계 필름의 주사전자현미경(Scanning electron microscope, SEM) 이미지를 나타낸 것이다. 1 shows a scanning electron microscope (SEM) image of the polyester film of Example 1.
도 2는 실시예 2의 폴리에스테르계 필름의 주사전자현미경(SEM) 이미지를 나타낸 것이다. Figure 2 shows a scanning electron microscope (SEM) image of the polyester film of Example 2.
도 3은 실시예 3의 폴리에스테르계 필름의 주사전자현미경(SEM) 이미지를 나타낸 것이다. Figure 3 shows a scanning electron microscope (SEM) image of the polyester-based film of Example 3.
도 4는 비교예 1의 폴리에스테르계 필름의 주사전자현미경(SEM) 이미지를 나타낸 것이다.Figure 4 shows a scanning electron microscope (SEM) image of the polyester-based film of Comparative Example 1.
도 5는 비교예 2의 폴리에스테르계 필름의 주사전자현미경(SEM) 이미지를 나타낸 것이다.5 shows a scanning electron microscope (SEM) image of the polyester film of Comparative Example 2.
도 6은 비교예 3의 폴리에스테르계 필름의 주사전자현미경(SEM) 이미지를 나타낸 것이다.6 shows a scanning electron microscope (SEM) image of the polyester film of Comparative Example 3.
이하, 구현예를 통해 발명을 상세하게 설명한다. 구현예는 이하에서 개시된 내용에 한정되는 것이 아니라 발명의 요지가 변경되지 않는 한, 다양한 형태로 변형될 수 있다.Hereinafter, the invention will be described in detail through embodiments. Embodiments are not limited to the contents disclosed below, and may be modified in various forms unless the gist of the invention is changed.
본 명세서에 있어서, 어떤 부분이 어떤 구성요소를 "포함" 한다고 할 때, 이는 특별히 반대되는 기재가 없는 한, 다른 구성요소를 제외하는 것이 아니라 다른 구성 요소를 더 포함할 수 있는 것을 의미한다.In this specification, when a certain component is said to "include", this means that it may further include other components, not excluding other components, unless otherwise stated.
본 명세서에 기재된 구성성분의 양, 반응 조건 등을 나타내는 모든 숫자 및 표현은 특별한 기재가 없는 한 모든 경우에 "약"이라는 용어로써 수식되는 것으로 이해하여야 한다.It should be understood that all numbers and expressions representing amounts of constituents, reaction conditions, etc. described herein are modified by the term "about" in all cases unless otherwise specified.
본 명세서에서 제 1, 제 2, 1차, 2차 등의 용어는 다양한 구성요소를 설명하기 위해 사용되는 것이고, 상기 구성요소들은 상기 용어에 의해 한정되지 않는다. 상기 용어들은 하나의 구성요소를 다른 구성요소로 구별하는 목적으로만 사용된다.In this specification, terms such as first, second, primary, and secondary are used to describe various components, and the components are not limited by the terms. These terms are only used for the purpose of distinguishing one component from another.
폴리에스테르계 필름polyester film
일 구현예에 따른 폴리에스테르계 필름은 디올 및 2종 이상의 디카르복실산이 공중합된 공중합 폴리에스테르계 수지; 및 필러를 포함하고, 하기 식 1에 따른 Rd가 2.5 이하이다.A polyester-based film according to an embodiment includes a co-polyester-based resin in which a diol and two or more dicarboxylic acids are copolymerized; and a filler, and R d according to Equation 1 below is 2.5 or less.
[식 1][Equation 1]
Figure PCTKR2022015165-appb-img-000002
Figure PCTKR2022015165-appb-img-000002
상기 식 1에 있어서,In the above formula 1,
Rmax는 폴리에스테르계 필름의 최대 높이 거칠기(㎛)이고, R max is the maximum height roughness (μm) of the polyester film,
Ra는 폴리에스테르계 필름의 중심선 평균 거칠기(㎛)이다.R a is the center line average roughness (μm) of the polyester-based film.
폴리에스테르계 필름은 일반적으로 롤(Roll)을 이용하여 제조되므로, 제조되는 폴리에스테르계 필름의 품질을 향상시키기 위해서 권취성 및 주행 성능과 같은 공정성을 향상시키는 것이 중요하다.Since a polyester film is generally manufactured using a roll, it is important to improve fairness such as winding property and driving performance in order to improve the quality of the polyester film produced.
종래에는 필름의 권취성 및 주행 성능과 같은 공정성을 향상시키기 위해서 유기 및 무기 첨가제를 사용해 왔으나, 이러한 첨가제를 사용하는 경우 인장강도 및 모듈러스와 같은 기계적 물성, 특히 투명성이 매우 저하되는 문제가 있다. 구체적으로, 폴리에스테르계 수지에 첨가제를 첨가하여 폴리에스테르계 필름을 제조하는 경우, 공정성은 향상될 수 있으나, 제조된 폴리에스테르계 필름의 인장강도 및 모듈러스와 같은 기계적 물성이 저하되고, 특히 헤이즈가 증가하여 투명성이 매우 낮아졌다.Conventionally, organic and inorganic additives have been used to improve fairness such as film winding and running performance, but when these additives are used, there is a problem in that mechanical properties such as tensile strength and modulus, in particular, transparency are greatly deteriorated. Specifically, when a polyester film is prepared by adding additives to the polyester resin, processability may be improved, but mechanical properties such as tensile strength and modulus of the prepared polyester film are lowered, and in particular, haze is reduced. increased, resulting in very low transparency.
그러나, 구현예에 따른 폴리에스테르계 필름은 디올 및 2종 이상의 디카르복실산이 공중합된 공중합 폴리에스테르계 수지와 필러를 포함함으로써, 필름의 표면조도를 효과적으로 제어하여 필름의 권취 및 주행 성능 등의 공정성을 향상시킬 뿐만 아니라, 기계적 물성 및 광학적 특성도 동시에 향상시킬 수 있다. 특히, 상기 폴리에스테르계 필름은 10점 평균 거칠기(Rz), 중심선 평균 거칠기(Ra) 및 최대 높이 거칠기(Rmax)가 모두 바람직한 범위를 만족하면서 분산성도 우수하여, 기계적 물성 및 광학적 특성을 저하시키기 않으면서 동시에 표면 특성도 향상시킬 수 있다. However, the polyester-based film according to the embodiment includes a co-polyester-based resin in which a diol and two or more kinds of dicarboxylic acids are copolymerized and a filler, thereby effectively controlling the surface roughness of the film to improve fairness such as winding and driving performance of the film. In addition to improving the mechanical properties and optical properties can be improved at the same time. In particular, the polyester film has excellent dispersibility while satisfying 10-point average roughness (R z ), center line average roughness (R a ) and maximum height roughness (R max ) within preferred ranges, thereby improving mechanical properties and optical properties. Surface properties can also be improved at the same time without deterioration.
구체적으로, 상기 폴리에스테르계 필름은 하기 식 1에 따른 Rd가 2.5 이하이다.Specifically, the polyester-based film has an R d of 2.5 or less according to Formula 1 below.
[식 1][Equation 1]
Figure PCTKR2022015165-appb-img-000003
Figure PCTKR2022015165-appb-img-000003
상기 식 1에 있어서,In the above formula 1,
Rmax는 폴리에스테르계 필름의 최대 높이 거칠기(㎛)이고, Ra는 폴리에스테르계 필름의 중심선 평균 거칠기(㎛)이다.R max is the maximum height roughness (μm) of the polyester-based film, and R a is the center line average roughness (μm) of the polyester-based film.
구체적으로, 상기 Rd는 폴리에스테르계 필름의 표면조도 특성 간의 비율을 나타내는 것으로, 상기 Rd는 2.3 이하, 2.0 이하, 1.8 이하 또는 1.6 이하일 수 있고, 0.3 내지 2.5, 0.5 내지 2.3, 0.5 내지 2.1, 0.6 내지 1.8, 0.8 내지 1.6 또는 0.9 내지 1.6일 수 있다. Rd 값이 상기 범위를 만족함으로써, 표면조도를 더욱 바람직한 범위로 제어하여 필름의 권취 및 주행 성능 등의 공정성을 향상시키면서, 기계적 물성과 광학적 특성을 동시에 향상시킬 수 있고, 특히 헤이즈를 감소시켜 투명성을 극대화할 수 있다.Specifically, the R d represents the ratio between the surface roughness characteristics of the polyester film, and the R d may be 2.3 or less, 2.0 or less, 1.8 or less, or 1.6 or less, 0.3 to 2.5, 0.5 to 2.3, 0.5 to 2.1 , 0.6 to 1.8, 0.8 to 1.6 or 0.9 to 1.6. When the R d value satisfies the above range, it is possible to simultaneously improve mechanical properties and optical properties while controlling the surface roughness to a more preferable range to improve fairness such as winding and running performance of the film, and in particular, transparency by reducing haze. can maximize
또한, 상기 폴리에스테르계 필름의 10점 평균 거칠기(Rz)는 0.8 ㎛ 이하이다. 예를 들어, 상기 폴리에스테르계 필름의 10점 평균 거칠기(Rz)는 0.7 ㎛ 이하, 0.6 ㎛ 이하, 0.5 ㎛ 이하 또는 0.3 ㎛ 이하일 수 있고, 0.01 ㎛ 내지 0.8 ㎛, 0.05 ㎛ 내지 0.6 ㎛, 0.1 ㎛ 내지 0.5 ㎛ 또는 0.15 ㎛ 내지 0.3 ㎛일 수 있다. In addition, the 10-point average roughness (R z ) of the polyester film is 0.8 μm or less. For example, the 10-point average roughness (R z ) of the polyester film may be 0.7 μm or less, 0.6 μm or less, 0.5 μm or less, or 0.3 μm or less, 0.01 μm to 0.8 μm, 0.05 μm to 0.6 μm, or 0.1 μm. μm to 0.5 μm or 0.15 μm to 0.3 μm.
상기 폴리에스테르계 필름의 중심선 평균 거칠기(Ra)는 0.05 ㎛ 이하이다. 예를 들어, 상기 폴리에스테르계 필름의 중심선 평균 거칠기(Ra)는 0.04 ㎛ 이하, 0.03 ㎛ 이하 또는 0.02 ㎛ 이하일 수 있고, 0.001 ㎛ 내지 0.05 ㎛, 0.005 ㎛ 내지 0.04 ㎛, 0.01 ㎛ 내지 0.03 ㎛ 또는 0.01 ㎛ 내지 0.03 ㎛일 수 있다.The center line average roughness (R a ) of the polyester-based film is 0.05 μm or less. For example, the center line average roughness (R a ) of the polyester film may be 0.04 μm or less, 0.03 μm or less, or 0.02 μm or less, 0.001 μm to 0.05 μm, 0.005 μm to 0.04 μm, 0.01 μm to 0.03 μm, or It may be 0.01 μm to 0.03 μm.
또한, 상기 폴리에스테르계 필름의 최대 높이 거칠기(Rmax)는 1.5 ㎛ 이하이다. 예를 들어, 상기 폴리에스테르계 필름의 최대 높이 거칠기(Rmax)는 1.4 ㎛ 이하, 1.3 ㎛ 이하, 1.1 ㎛ 이하 또는 1.0 ㎛ 이하일 수 있고, 0.1 ㎛ 내지 1.5 ㎛, 0.2 ㎛ 내지 1.4 ㎛, 0.5 ㎛ 내지 1.3 ㎛, 0.6 ㎛ 내지 1.1 ㎛ 또는 0.7 ㎛ 내지 1.0 ㎛일 수 있다.In addition, the maximum height roughness (R max ) of the polyester-based film is 1.5 μm or less. For example, the maximum height roughness (R max ) of the polyester film may be 1.4 μm or less, 1.3 μm or less, 1.1 μm or less, or 1.0 μm or less, 0.1 μm to 1.5 μm, 0.2 μm to 1.4 μm, or 0.5 μm. to 1.3 μm, 0.6 μm to 1.1 μm, or 0.7 μm to 1.0 μm.
폴리에스테르계 필름의 10점 평균 거칠기(Rz), 중심선 평균 거칠기(Ra) 및 최대 높이 거칠기(Rmax)가 각각 상기 범위를 만족함으로써, 표면조도를 바람직한 범위로 제어하여 필름의 권취 및 주행 성능 등의 공정성을 향상시킬 수 있고, 기계적 물성 및 광학적 특성을 저하시키기 않으면서 동시에 표면 특성도 향상시킬 수 있다.When the 10-point average roughness (R z ), the center line average roughness (R a ), and the maximum height roughness (R max ) of the polyester-based film each satisfy the above ranges, the surface roughness is controlled to a desirable range to wind and run the film. Processability, such as performance, can be improved, and surface properties can be improved at the same time without deteriorating mechanical properties and optical properties.
상기 10점 평균 거칠기(Rz), 중심선 평균 거칠기(Ra) 및 최대 높이 거칠기(Rmax)와 같은 표면조도는 2차원 접촉식 표면조도 측정기(Kosaka 사의 SE3300)을 이용하여 측정될 수 있다.Surface roughness such as the 10-point average roughness (R z ), center line average roughness (R a ), and maximum height roughness (R max ) may be measured using a two-dimensional contact surface roughness meter (SE3300 manufactured by Kosaka).
구체적으로, 상기 10점 평균 거칠기(Rz)는 KS B 0161에 따른 표면조도이다. 필름의 표면과 직각인 평면으로 표면을 절단하였을 때 그 절단면에 나타나는 일부 구간을 확대하여 기록한 단면곡선에서 기준길이만큼 채취하고, 상기 단면곡선의 평균선과 평행한 임의의 직선을 기준선으로 설정한다. 이때, 가장 높은 5개의 산에 대하여, 기준선으로부터의 거리에 대한 평균값과 가장 낮은 5개의 골에 대하여 기준선으로부터의 거리에 대한 평균값의 차이로 계산할 수 있다.Specifically, the 10-point average roughness (R z ) is surface roughness according to KS B 0161. When the surface is cut with a plane perpendicular to the surface of the film, a portion of the section appearing on the cut surface is enlarged and taken as much as the reference length from the recorded cross-sectional curve, and an arbitrary straight line parallel to the average line of the cross-sectional curve is set as the reference line. At this time, it can be calculated as the difference between the average value of the distance from the reference line for the five highest peaks and the average value for the distance from the reference line for the five lowest valleys.
상기 중심선 평균 거칠기(Ra)는 KS B 0161에 따른 표면조도로서, 거칠기 곡선에서 산을 깎아 골을 메웠을 때 생기는 직선을 중심선이라 하며, 그 중심선의 방향으로 측정길이를 채취하고, 상기 중심선으로부터 아래쪽에 있는 부분을 위쪽으로 접어서 얻은 윗부분의 면적을 상기 측정길이로 나누어 계산할 수 있다. The center line average roughness (R a ) is a surface roughness according to KS B 0161, and a straight line generated when a mountain is cut from a roughness curve to fill a valley is called a center line, and a measured length is taken in the direction of the center line, and from the center line It can be calculated by dividing the area of the upper part obtained by folding the lower part upwards by the measured length.
상기 최대 높이 거칠기(Rmax)는 KS B 0161에 따른 표면조도로서, 단면곡선에서 기준길이를 채취하고, 상기 단면곡선의 중심선과 평행하며 가장 높은 산과 가장 깊은 골을 접하는 두 평행선 간의 거리로 계산할 수 있다.The maximum height roughness (R max ) is a surface roughness according to KS B 0161, a reference length is taken from a cross-sectional curve, and it is parallel to the center line of the cross-sectional curve and the highest peak and the deepest valley. Can be calculated as the distance between two parallel lines. there is.
또한, 상기 폴리에스테르계 필름은 식 2에 따른 RF가 0.8 이하일 수 있다. In addition, the polyester-based film may have an RF of 0.8 or less according to Equation 2.
[식 2][Equation 2]
Figure PCTKR2022015165-appb-img-000004
Figure PCTKR2022015165-appb-img-000004
식 2에 있어서, In Equation 2,
Rmax는 폴리에스테르계 필름의 최대 높이 거칠기(㎛)이고, Fd는 폴리에스테르계 필름의 동마찰계수이다.R max is the maximum height roughness (μm) of the polyester-based film, and F d is the kinetic friction coefficient of the polyester-based film.
구체적으로, 상기 RF는 폴리에스테르계 필름의 표면 특성 간의 비율을 나타내는 것으로, 상기 RF는 0.75 이하, 0.7 이하, 0.65 이하, 0.6 이하 또는 0.55 이하일 수 있고, 0.05 내지 0.8, 0.05 내지 0.8, 0.08 내지 0.7, 0.1 내지 0.65, 0.15 내지 0.6, 0.2 내지 0.6 또는 0.3 내지 0.55일 수 있다. RF 값이 상기 범위를 만족함으로써, 표면조도를 더욱 바람직한 범위로 제어하여 기계적 물성과 광학적 특성을 동시에 향상시킬 수 있고, 특히 헤이즈를 감소시켜 투명성을 극대화할 수 있다. Specifically, the RF represents the ratio between the surface properties of the polyester-based film, the RF may be 0.75 or less, 0.7 or less, 0.65 or less, 0.6 or less, or 0.55 or less, 0.05 to 0.8, 0.05 to 0.8, 0.08 to 0.7 , 0.1 to 0.65, 0.15 to 0.6, 0.2 to 0.6 or 0.3 to 0.55. When the RF value satisfies the above range, surface roughness can be controlled to a more preferable range to simultaneously improve mechanical properties and optical properties, and in particular, transparency can be maximized by reducing haze.
상기 폴리에스테르계 필름의 동마찰계수(Fd)는 0.6 이하일 수 있고, 정마찰계수(Fs)는 0.75 이하일 수 있다. 예를 들어, 상기 필름의 표면 동마찰계수(Fd)는 0.5 이하 또는 0.55 이하일 수 있고, 상기 필름의 표면 정마찰계수(Fs)는 0.74 이하, 0.73 이하, 0.7 이하 또는 0.68 이하일 수 있다.The polyester-based film may have a dynamic coefficient of friction (F d ) of 0.6 or less, and a static coefficient of friction (F s ) of 0.75 or less. For example, the surface dynamic friction coefficient (F d ) of the film may be 0.5 or less or 0.55 or less, and the surface static friction coefficient (F s ) of the film may be 0.74 or less, 0.73 or less, 0.7 or less, or 0.68 or less.
필름의 동마찰계수(Fd) 및 정마찰계수(Fs)가 상기 범위를 만족함으로써, 기계적 물성 및 광학적 특성을 모두 향상시킬 수 있다. 구체적으로, 표면조도와 표면 마찰계수는 정확히 비례관계는 아니며, 표면조도와 표면 마찰계수가 각각 상기 범위를 만족함으로써, 기계적 물성의 저하 없이 헤이즈를 감소시켜 투명성을 극대화할 수 있다. When the kinetic coefficient of friction (F d ) and the coefficient of static friction (F s ) of the film satisfy the above ranges, both mechanical properties and optical properties can be improved. Specifically, the surface roughness and the surface friction coefficient are not exactly proportional, and when the surface roughness and the surface friction coefficient satisfy the above ranges, respectively, haze can be reduced without deterioration of mechanical properties, thereby maximizing transparency.
상기 폴리에스테르계 필름의 헤이즈는 8% 이하일 수 있다. 예를 들어, 상기 폴리에스테르계 필름의 헤이즈는 8% 이하, 6% 이하, 5% 이하 또는 4.5% 이하일 수 있다. 구현예에 따른 폴리에스테르계 필름은 필러를 포함하면서도 헤이즈가 상기 범위를 만족함으로써, 기계적 물성이 우수하면서 뛰어난 투명성을 갖는다.Haze of the polyester film may be 8% or less. For example, the haze of the polyester film may be 8% or less, 6% or less, 5% or less, or 4.5% or less. The polyester-based film according to the embodiment has excellent transparency while having excellent mechanical properties by having a haze that satisfies the above range while including a filler.
또한, 상기 폴리에스테르계 필름의 400 nm 내지 700 nm의 파장에서 투과율은 88% 이상일 수 있다. 예를 들어, 상기 폴리에스테르계 필름의 400 nm 내지 700 nm의 파장에서 투과율은 88.5% 이상, 89% 이상 또는 89.5% 이상일 수 있다. In addition, the transmittance of the polyester-based film may be 88% or more at a wavelength of 400 nm to 700 nm. For example, the transmittance of the polyester film at a wavelength of 400 nm to 700 nm may be 88.5% or more, 89% or more, or 89.5% or more.
상기 폴리에스테르계 필름의 인장강도는 19 kgf/mm2 이하일 수 있다. 구체적으로, 상기 폴리에스테르계 필름의 면내 제 1 방향의 인장강도는 19 kgf/mm2 이하, 18 kgf/mm2 이하, 16 kgf/mm2 이하 또는 15 kgf/mm2 이하일 수 있고, 10 kgf/mm2 내지 19 kgf/mm2, 10 kgf/mm2 내지 16 kgf/mm2 또는 10 kgf/mm2 내지 15 kgf/mm2 일 수 있다.Tensile strength of the polyester film may be 19 kgf/mm 2 or less. Specifically, the tensile strength of the in-plane first direction of the polyester film may be 19 kgf/mm 2 or less, 18 kgf/mm 2 or less, 16 kgf/mm 2 or less, or 15 kgf/mm 2 or less, and 10 kgf/mm 2 or less. mm 2 to 19 kgf/mm 2 , 10 kgf/mm 2 to 16 kgf/mm 2 or 10 kgf/mm 2 to 15 kgf/mm 2 .
또한, 상기 폴리에스테르계 필름의 면내 제 1 방향과 수직한 제 2 방향의 인장강도는 19 kgf/mm2 이하 또는 18.5 kgf/mm2 이하일 수 있고, 10 kgf/mm2 내지 19 kgf/mm2, 12 kgf/mm2 내지 19 kgf/mm2, 13 kgf/mm2 내지 18.5 kgf/mm2 또는 14.5 kgf/mm2 내지 18.5 kgf/mm2일 수 있다. In addition, the tensile strength in the second direction perpendicular to the first direction in the plane of the polyester film may be 19 kgf/mm 2 or less or 18.5 kgf/mm 2 or less, 10 kgf/mm 2 to 19 kgf/mm 2 , 12 kgf/mm 2 to 19 kgf/mm 2 , 13 kgf/mm 2 to 18.5 kgf/mm 2 or 14.5 kgf/mm 2 to 18.5 kgf/mm 2 .
폴리에스테르계 필름의 인장강도가 상기 범위를 만족함으로써, 우수한 기계적 물성으로 인해 금속 대체용, 전자기판 또는 디스플레이 소자 등에 있어서 다양한 활용이 가능하고, 경량화를 구현하는 데에 더욱 유리할 수 있다.When the tensile strength of the polyester-based film satisfies the above range, it can be used in a variety of ways, such as for metal replacement, electronic boards or display devices, and can be more advantageous in implementing weight reduction due to excellent mechanical properties.
본 명세서에 있어서, 상기 제 1 방향은 폭 방향(TD) 또는 길이 방향(MD)일 수 있다. 구체적으로, 상기 제 1 방향은 길이 방향(MD)일 수 있고, 상기 제 1 방향과 수직한 제 2 방향은 폭 방향(TD)일 수 있다.In the present specification, the first direction may be a width direction (TD) or a length direction (MD). Specifically, the first direction may be a length direction (MD), and the second direction perpendicular to the first direction may be a width direction (TD).
또한, 상기 폴리에스테르계 필름의 파단신율은 30% 이상일 수 있다. 구체적으로, 상기 폴리에스테르계 필름의 면내 제 1 방향의 파단신율은 30% 이상, 35% 이상, 40% 이상, 42% 이상일 수 있고, 상기 폴리에스테르계 필름의 면내 제 1 방향과 수직한 제 2 방향의 파단신율은 30% 이상, 32% 이상 또는 34% 이상일 수 있다. In addition, the elongation at break of the polyester-based film may be 30% or more. Specifically, the elongation at break in the first in-plane direction of the polyester-based film may be 30% or more, 35% or more, 40% or more, or 42% or more, and the second in-plane direction perpendicular to the first direction of the polyester-based film The elongation at break in the direction may be 30% or more, 32% or more, or 34% or more.
폴리에스테르계 필름의 파단신율이 상기 범위를 만족함으로써, 우수한 기계적 물성으로 인해 금속 대체용, 전자기판 또는 디스플레이 소자 등에 있어서 다양한 활용이 가능하고, 경량화를 구현하는 데에 더욱 유리할 수 있다.When the elongation at break of the polyester film satisfies the above range, it can be used in a variety of ways for metal replacement, electronic boards or display devices due to its excellent mechanical properties, and can be more advantageous in implementing weight reduction.
상기 폴리에스테르계 필름의 모듈러스는 320 kgf/mm2 이하일 수 있다. 구체적으로, 상기 폴리에스테르계 필름의 면내 제 1 방향의 모듈러스는 320 kgf/mm2 이하, 310 kgf/mm2 이하, 300 kgf/mm2 이하, 290 kgf/mm2 이하 또는 288 kgf/mm2 이하일 수 있고, 230 kgf/mm2 내지 300 kgf/mm2, 250 kgf/mm2 내지 290 kgf/mm2, 255 kgf/mm2 내지 290 kgf/mm2, 260 kgf/mm2 내지 300 kgf/mm2, 260 kgf/mm2 내지 290 kgf/mm2 또는 260 kgf/mm2 내지 288 kgf/mm2 일 수 있다. Modulus of the polyester-based film may be 320 kgf/mm 2 or less. Specifically, the modulus of the polyester-based film in the first direction in the plane is 320 kgf/mm 2 or less, 310 kgf/mm 2 or less, 300 kgf/mm 2 or less, 290 kgf/mm 2 or less, or 288 kgf/mm 2 or less. May be, 230 kgf / mm 2 to 300 kgf / mm 2 , 250 kgf / mm 2 to 290 kgf / mm 2 , 255 kgf / mm 2 to 290 kgf / mm 2 , 260 kgf / mm 2 to 300 kgf / mm 2 , 260 kgf/mm 2 to 290 kgf/mm 2 or 260 kgf/mm 2 to 288 kgf/mm 2 .
또한, 상기 폴리에스테르계 필름의 면내 제 1 방향과 수직한 제 2 방향의 모듈러스는 320 kgf/mm2 이하, 310 kgf/mm2 이하, 305 kgf/mm2 이하, 300 kgf/mm2 이하 또는 299 kgf/mm2 이하일 수 있고, 230 kgf/mm2 내지 320 kgf/mm2, 260 kgf/mm2 내지 310 kgf/mm2, 275 kgf/mm2 내지 320 kgf/mm2, 275 kgf/mm2 내지 300 kgf/mm2 또는 280 kgf/mm2 내지 299 kgf/mm2일 수 있다.In addition, the modulus of the polyester film in the second direction perpendicular to the first in-plane direction is 320 kgf/mm 2 or less, 310 kgf/mm 2 or less, 305 kgf/mm 2 or less, 300 kgf/mm 2 or less, or 299 kgf/mm 2 or less, 230 kgf/mm 2 to 320 kgf/mm 2 , 260 kgf/mm 2 to 310 kgf/mm 2 , 275 kgf/mm 2 to 320 kgf/mm 2 , 275 kgf/mm 2 to 300 kgf/mm 2 or 280 kgf/mm 2 to 299 kgf/mm 2 .
상기 인장강도, 파단신율 및 모듈러스는 ASTM D 882에 따라 상온에서 인스트론(INSTRON)사의 만능시험기(4206-001, 제조사: UTM)에 의해 측정될 수 있다. The tensile strength, elongation at break and modulus may be measured at room temperature according to ASTM D 882 by using a universal testing machine (4206-001, manufactured by INSTRON).
또한, 상기 폴리에스테르계 필름의 두께는 1 ㎛ 내지 500 ㎛, 5 내지 250 ㎛, 10 내지 150 ㎛, 10 ㎛ 내지 100 ㎛, 10 ㎛ 내지 80 ㎛, 또는 30 ㎛ 내지 60 ㎛일 수 있다.In addition, the polyester-based film may have a thickness of 1 μm to 500 μm, 5 to 250 μm, 10 to 150 μm, 10 μm to 100 μm, 10 μm to 80 μm, or 30 μm to 60 μm.
또한, 상기 폴리에스테르계 필름은 디올 및 2종 이상의 디카르복실산이 공중합된 공중합 폴리에스테르계 수지를 포함한다. In addition, the polyester-based film includes a co-polyester-based resin in which a diol and two or more kinds of dicarboxylic acids are copolymerized.
상기 디올은 시클로헥산디메탄올 또는 이의 유도체를 포함한다. 예를 들어, 상기 디올은 1,2-시클로헥산디메탄올, 1,3-시클로헥산디메탄올 또는 1,4-시클로헥산디메탄올을 포함할 수 있고, 바람직하게는 1,4-시클로헥산디메탄올을 포함할 수 있다. 더욱 구체적으로, 상기 디올은 1,4-시클로헥산디메탄올 또는 이의 유도체를 포함할 수 있다.The diol includes cyclohexanedimethanol or a derivative thereof. For example, the diol may include 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol or 1,4-cyclohexanedimethanol, preferably 1,4-cyclohexanedimethanol can include More specifically, the diol may include 1,4-cyclohexanedimethanol or a derivative thereof.
또한, 상기 디올은 시클로헥산디메탄올 또는 이의 유도체를 70 몰% 이상으로 포함할 수 있다. 예를 들어, 상기 공중합 폴리에스테르계 수지는 상기 디올의 총 몰수를 기준으로 시클로헥산디메탄올 또는 이의 유도체를 72 몰% 이상, 75 몰% 이상, 85 몰% 이상, 88 몰% 이상, 90 몰% 이상, 93 몰% 이상, 95 몰% 이상, 97 몰% 이상, 99 몰% 이상 또는 100 몰%로 포함할 수 있다. In addition, the diol may include 70 mol% or more of cyclohexanedimethanol or a derivative thereof. For example, the copolyester-based resin contains cyclohexanedimethanol or a derivative thereof in an amount of 72 mol% or more, 75 mol% or more, 85 mol% or more, 88 mol% or more, or 90 mol% based on the total number of moles of the diol. or more, 93 mol% or more, 95 mol% or more, 97 mol% or more, 99 mol% or more, or 100 mol%.
상기 디올이 시클로헥산디메탄올 또는 이의 유도체를 포함함으로써 유연성, 내구성 및 내가수분해성을 향상시킬 수 있으며, 상기 디올이 시클로헥산디메탄올로만 구성되는 경우, 내구성, 내열성 및 내가수분해성을 극대화할 수 있다.Flexibility, durability, and hydrolysis resistance can be improved by including cyclohexanedimethanol or a derivative thereof in the diol, and durability, heat resistance, and hydrolysis resistance can be maximized when the diol is composed of only cyclohexanedimethanol. .
또한, 상기 디올은 필요에 따라 에틸렌글리콜, 네오펜틸글리콜 및 디에틸렌글리콜로 이루어진 군으로부터 선택된 1종 이상을 포함할 수 있다. 예를 들어, 상기 공중합 폴리에스테르계 수지는 상기 디올의 총 몰수를 기준으로 에틸렌글리콜, 네오펜틸글리콜 및 디에틸렌글리콜로 이루어진 군으로부터 선택된 1종 이상을 1 몰% 내지 30 몰%, 1 몰% 내지 20 몰%, 1 몰% 내지 15 몰%, 1 몰% 내지 10 몰% 또는 1 몰% 내지 5 몰%로 포함할 수 있다. In addition, the diol may include at least one selected from the group consisting of ethylene glycol, neopentyl glycol, and diethylene glycol, if necessary. For example, the copolymerized polyester-based resin contains 1 mol% to 30 mol%, 1 mol% to 1 mol% of at least one selected from the group consisting of ethylene glycol, neopentyl glycol and diethylene glycol based on the total number of moles of the diol. 20 mol%, 1 mol% to 15 mol%, 1 mol% to 10 mol%, or 1 mol% to 5 mol%.
상기 디카르복실산은 2종 이상의 디카르복실산을 포함할 수 있다. 구체적으로, 상기 디카르복실산은 제 1 디카르복실산 및 제 2 디카르복실산을 포함할 수 있으며, 상기 제1 디카르복실산은 테레프탈산일 수 있으며, 상기 제2 디카르복실산은 이소프탈산일 수 있다.The dicarboxylic acid may include two or more dicarboxylic acids. Specifically, the dicarboxylic acid may include a first dicarboxylic acid and a second dicarboxylic acid, the first dicarboxylic acid may be terephthalic acid, and the second dicarboxylic acid may be isophthalic acid. there is.
보다 구체적으로, 상기 디카르복실산은 70 몰% 내지 99 몰%의 테레프탈산 및 1 몰% 내지 30 몰%의 이소프탈산을 포함할 수 있다. 예를 들어, 상기 공중합 폴리에스테르계 수지는 상기 디카르복실산의 총 몰수를 기준으로 테레프탈산을 73 몰% 내지 99 몰%, 75 몰% 내지 99 몰%, 80 몰% 내지 98 몰%, 83 몰% 내지 98 몰% 또는 85 몰% 내지 98 몰%로 포함할 수 있고, 이소프탈산을 1 몰% 내지 28 몰%, 1 몰% 내지 25 몰%, 1 몰% 내지 20 몰%, 2 몰% 내지 15 몰%, 3 몰% 내지 13 몰%, 3 몰% 내지 10 몰% 또는 3 몰% 내지 8 몰%로 포함할 수 있다. 테레프탈산 및 이소프탈산의 함량이 상기 범위를 만족함으로써, 유연성, 내구성, 내열성 및 내가수분해성을 향상시킬 수 있다.More specifically, the dicarboxylic acid may include 70 mol% to 99 mol% of terephthalic acid and 1 mol% to 30 mol% of isophthalic acid. For example, the copolyester-based resin contains 73 mol% to 99 mol%, 75 mol% to 99 mol%, 80 mol% to 98 mol%, 83 mol% of terephthalic acid based on the total number of moles of the dicarboxylic acid. % to 98 mol% or 85 mol% to 98 mol%, and 1 mol% to 28 mol%, 1 mol% to 25 mol%, 1 mol% to 20 mol%, 2 mol% to 2 mol% isophthalic acid 15 mol%, 3 mol% to 13 mol%, 3 mol% to 10 mol%, or 3 mol% to 8 mol%. When the contents of terephthalic acid and isophthalic acid satisfy the above ranges, flexibility, durability, heat resistance and hydrolysis resistance may be improved.
또한, 상기 공중합 폴리에스테르계 수지는 상기 제 1 및 제 2 디카르복실산 이외의 추가 디카르복실산을 포함할 수 있다. 상기 추가 디카르복실산은 디메틸테레프탈산을 포함할 수 있으며, 예를 들어, 상기 공중합 폴리에스테르계 수지는 디카르복실산의 총 몰수를 기준으로 1 몰% 내지 15 몰%, 1 몰% 내지 10 몰% 또는 3 몰% 내지 7 몰%의 디메틸테레프탈산을 추가로 포함할 수 있다.In addition, the co-polyester-based resin may include an additional dicarboxylic acid other than the first and second dicarboxylic acids. The additional dicarboxylic acid may include dimethyl terephthalic acid, and for example, the co-polyester-based resin is present in an amount of 1 mol% to 15 mol%, 1 mol% to 10 mol% based on the total number of moles of the dicarboxylic acid. Or 3 mol% to 7 mol% of dimethyl terephthalic acid may be further included.
구현예에 따른 공중합 폴리에스테르계 수지는 폴리사이클로헥실렌디메틸렌 테레프탈레이트(PCT) 수지를 포함할 수 있다.The co-polyester-based resin according to the embodiment may include a polycyclohexylenedimethylene terephthalate (PCT) resin.
구체적으로, 상기 공중합 폴리에스테르계 수지가 폴리사이클로헥실렌디메틸렌 테레프탈레이트(PCT) 수지를 포함함으로써, 폴리에틸렌 테레프탈레이트(PET) 수지 및 폴리부틸렌 테레프탈레이트(PBT) 수지에 비하여 우수한 내열성, 내화학성 및 내흡습성을 가질 수 있다. 따라서, 높은 온도에서 용융압출, 연신 등을 거치는 제조 과정에서 우수한 결정화 특성으로 인해 결정화도가 상승하면서 인장강도 및 모듈러스와 같은 기계적 물성이 향상될 수 있다.Specifically, since the copolymerized polyester-based resin includes polycyclohexylenedimethylene terephthalate (PCT) resin, it has excellent heat resistance and chemical resistance compared to polyethylene terephthalate (PET) resin and polybutylene terephthalate (PBT) resin. and hygroscopicity. Therefore, mechanical properties such as tensile strength and modulus may be improved while crystallinity increases due to excellent crystallization characteristics during the manufacturing process through melt extrusion, stretching, etc. at a high temperature.
이때, 제조 과정에서 원치 않은 결정화가 발생할 수 있으나, 상기 공중합 폴리에스테르계 수지는 디카르복실산으로서 1 몰% 내지 30 몰%의 이소프탈산을 포함하므로, 사이클로헥실렌디메틸렌이 포함됨에 따라 지나치게 높아질 수 있는 결정화 속도를 낮추면서 용융점(Tm)을 낮추어 중합체의 취급성을 높이는데 보다 유리하다.At this time, undesirable crystallization may occur during the manufacturing process, but since the copolyester-based resin contains 1 mol% to 30 mol% of isophthalic acid as dicarboxylic acid, it may be excessively high as cyclohexylenedimethylene is included. It is more advantageous to increase the handleability of the polymer by lowering the melting point (Tm) while lowering the possible crystallization rate.
또한, 상기 폴리에스테르계 필름은 상기 공중합 폴리에스테르계 수지를 85 중량% 이상으로 포함할 수 있다. 예를 들어, 상기 공중합 폴리에스테르계 수지의 함량은 상기 폴리에스테르계 필름 총 중량을 기준으로 88 중량% 이상, 90 중량% 이상, 93 중량% 이상, 95 중량% 이상, 98 중량% 이상, 99 중량% 이상 또는 100 중량%일 수 있고, 85 중량% 내지 100 중량%, 90 중량% 내지 100 중량%, 95 중량% 내지 100 중량% 또는 98 중량% 내지 100 중량%일 수 있다. In addition, the polyester-based film may include 85% by weight or more of the co-polyester-based resin. For example, the content of the co-polyester-based resin is 88% by weight or more, 90% by weight or more, 93% by weight or more, 95% by weight or more, 98% by weight or more, 99% by weight or more based on the total weight of the polyester-based film. % or more than 100%, 85% to 100%, 90% to 100%, 95% to 100% or 98% to 100%.
또한, 상기 공중합 폴리에스테르계 수지는 자외선안정제, 열안정제, 산화방지제 및 불활성 입자로 이루어진 군으로부터 선택된 1종 이상의 첨가제를 추가로 포함할 수 있다.In addition, the co-polyester-based resin may further include at least one additive selected from the group consisting of an ultraviolet stabilizer, a heat stabilizer, an antioxidant, and an inert particle.
구체적으로, 상기 자외선안정제는 벤조페논계, 벤조트리아졸계, 시아노아크릴레이트계 및 살리실산에스테르계 화합물로 이루어진 군으로부터 선택된 1종 이상일 수 있고, 상기 열안정제는 요오드계 화합물일 수 있으며, 상기 산화방지제는 인계 산화방지제, 페놀계 산화방지제 또는 황계 산화방지제일 수 있고, 상기 불활성 입자는 실리카나 탄산칼륨일 수 있으나, 이에 한정되는 것은 아니다. Specifically, the UV stabilizer may be at least one selected from the group consisting of benzophenone-based, benzotriazole-based, cyanoacrylate-based, and salicylic acid ester-based compounds, the heat stabilizer may be an iodine-based compound, and the antioxidant may be a phosphorus-based antioxidant, a phenol-based antioxidant, or a sulfur-based antioxidant, and the inert particle may be silica or potassium carbonate, but is not limited thereto.
상기 첨가제의 함량은 상기 공중합 폴리에스테르계 수지 총 중량을 기준으로 0.5 중량% 내지 15 중량%, 1 중량% 내지 13 중량%, 1.2 중량% 내지 12 중량%, 1.5 중량% 내지 10 중량%, 1.7 중량% 내지 8 중량% 또는 1.8 중량% 내지 7.5 중량%일 수 있다.The content of the additive is 0.5% to 15% by weight, 1% to 13% by weight, 1.2% to 12% by weight, 1.5% to 10% by weight, 1.7% by weight based on the total weight of the co-polyester-based resin. % to 8% or 1.8% to 7.5%.
또한, 상기 폴리에스테르계 필름은 필러를 포함할 수 있다. In addition, the polyester-based film may include a filler.
구체적으로, 구현예에 따른 폴리에스테르계 필름은 상기 필러의 종류, 물성 및 함량에 따라 폴리에스테르계 필름의 10점 평균 거칠기(Rz), 중심선 평균 거칠기(Ra) 및 최대 높이 거칠기(Rmax)와 같은 표면조도 특성은 물론, 마찰계수, 인장강도, 파단신율 및 모듈러스와 같은 기계적 물성과 헤이즈 및 광투과율과 같은 광학적 특성이 달라질 수 있다. 특히, 상기 폴리에스테르계 필름은 상기 필러를 포함함으로써, 표면조도를 바람직한 범위로 제어하여 기계적 물성을 저하시키기 않으면서 광학적 특성, 특히 헤이즈가 낮아 투명성이 매우 우수하다. Specifically, the polyester film according to the embodiment has a 10-point average roughness (R z ), center line average roughness (R a ) and maximum height roughness (R max ) of the polyester film according to the type, physical properties and content of the filler. ), as well as mechanical properties such as friction coefficient, tensile strength, elongation at break and modulus, and optical properties such as haze and light transmittance may vary. In particular, the polyester-based film, by including the filler, controls the surface roughness to a desirable range and has excellent optical properties, particularly low haze, and excellent transparency without deteriorating mechanical properties.
또한, 상기 필러의 함량이 동일하더라도, 필러의 입자 크기, 형태 및 물성에 따라 필름의 표면조도 특성 및 광학적 특성이 현저히 달라질 수 있다.In addition, even if the content of the filler is the same, the surface roughness characteristics and optical characteristics of the film may be significantly different depending on the particle size, shape, and physical properties of the filler.
상기 필러는 이산화티탄, 황산바륨, 탄산칼슘, 탄산마그네슘, 탄산아연, 산화아연, 산화마그네슘, 알루미나, 및 실리카로 이루어진 군으로부터 선택된 1종 이상을 포함할 수 있다. 구체적으로, 상기 필러가 실리카를 포함하는 경우, 광학적 특성면에서 바람직할 수 있으나, 이에 한정되는 것은 아니다. The filler may include at least one selected from the group consisting of titanium dioxide, barium sulfate, calcium carbonate, magnesium carbonate, zinc carbonate, zinc oxide, magnesium oxide, alumina, and silica. Specifically, when the filler includes silica, it may be preferable in terms of optical properties, but is not limited thereto.
또한, 상기 필러는 구의 형상을 갖는 구상일 수 있다. 구체적으로, 상기 폴리에스테르계 필름이 구의 형상을 갖는 구상의 필러를 포함함으로써, 덩어리 형태인 괴상의 필러를 포함하는 경우에 비하여, 분산성을 더욱 향상시켜 표면조도를 더욱 효과적으로 제어할 수 있으면서 우수한 표면 특성을 가질 수 있다.In addition, the filler may be spherical having a spherical shape. Specifically, by including a spherical filler having a spherical shape, the polyester film can further improve dispersibility and control the surface roughness more effectively, as compared to the case of including a bulky filler in the form of a lump. may have characteristics.
더욱 구체적으로, 상기 필러가 구 형상의 실리카 비드를 포함할 있고, 상기 필러가 구의 형상을 갖는 구상의 실리카 비드를 포함하는 경우, 표면조도를 더욱 효과적으로 제어할 수 있으면서 헤이즈를 감소시켜 투명성을 극대화할 수 있다. More specifically, the filler may include spherical silica beads, and when the filler includes spherical silica beads, surface roughness can be more effectively controlled and haze can be reduced to maximize transparency. can
상기 필러의 평균 입경(Dsem)은 0.01 ㎛ 내지 2.0 ㎛일 수 있다. 예를 들어, 상기 필러의 평균 입경(Dsem)은 0.01 ㎛ 내지 1.9 ㎛, 0.01 ㎛ 내지 1.8 ㎛, 0.02 ㎛ 내지 1.3 ㎛, 0.03 ㎛ 내지 1.0 ㎛, 0.05 ㎛ 내지 0.8 ㎛, 0.1 ㎛ 내지 0.5 ㎛ 또는 0.15 ㎛ 내지 0.4 ㎛일 수 있다. 필러의 평균 입경(Dsem)이 상기 범위를 만족함으로써, 표면조도를 더욱 효과적으로 제어할 수 있으면서 헤이즈를 감소시켜 투명성을 극대화할 수 있다.The average particle diameter (D sem ) of the filler may be 0.01 μm to 2.0 μm. For example, the average particle diameter (D sem ) of the filler is 0.01 μm to 1.9 μm, 0.01 μm to 1.8 μm, 0.02 μm to 1.3 μm, 0.03 μm to 1.0 μm, 0.05 μm to 0.8 μm, 0.1 μm to 0.5 μm, or It may be 0.15 μm to 0.4 μm. When the average particle diameter (D sem ) of the filler satisfies the above range, surface roughness can be more effectively controlled and haze can be reduced to maximize transparency.
특히, 폴리에스테르계 필름은 연신 온도, 연신율, 열고정 온도 등과 같은 공정 조건을 조절하여 향상시킬 수 있는 인장강도, 파단신율 및 모듈러스와 같은 기계적 물성의 한계가 있다. 그러나, 구현예에 따른 폴리에스테르계 필름은 평균 입경이 상기 범위를 만족하는 필러를 포함함으로써, 기존 공정 조건을 유지하여 추가 공정 비용 없이 인장강도, 파단신율 및 모듈러스와 같은 기계적 물성을 더욱 향상시킬 수 있다. In particular, polyester-based films have limitations in mechanical properties such as tensile strength, elongation at break, and modulus that can be improved by adjusting process conditions such as stretching temperature, elongation rate, and heat setting temperature. However, the polyester-based film according to the embodiment may further improve mechanical properties such as tensile strength, elongation at break and modulus without additional process cost by maintaining existing process conditions by including a filler having an average particle diameter satisfying the above range. there is.
상기 필러의 D10은 0.05 ㎛ 내지 0.5 ㎛일 수 있다. 예를 들어, 상기 필러의 D10은 0.05 ㎛ 내지 0.45 ㎛, 0.1 ㎛ 내지 0.4 ㎛, 0.13 ㎛ 내지 0.36 ㎛, 0.18 ㎛ 내지 0.33 ㎛, 0.2 ㎛ 내지 0.31 ㎛ 또는 0.21 ㎛ 내지 0.28 ㎛일 수 있다.D 10 of the filler may be 0.05 μm to 0.5 μm. For example, the D 10 of the filler may be 0.05 μm to 0.45 μm, 0.1 μm to 0.4 μm, 0.13 μm to 0.36 μm, 0.18 μm to 0.33 μm, 0.2 μm to 0.31 μm, or 0.21 μm to 0.28 μm.
또한, 상기 필러의 D50은 0.12 ㎛ 내지 0.65 ㎛일 수 있다. 예를 들어, 상기 필러의 D50은 0.14 ㎛ 내지 0.55 ㎛, 0.16 ㎛ 내지 0.5 ㎛, 0.18 ㎛ 내지 0.35 ㎛, 0.22 ㎛ 내지 0.32 ㎛ 또는 0.25 ㎛ 내지 0.3 ㎛일 수 있다. In addition, D 50 of the filler may be 0.12 μm to 0.65 μm. For example, the D 50 of the filler may be 0.14 μm to 0.55 μm, 0.16 μm to 0.5 μm, 0.18 μm to 0.35 μm, 0.22 μm to 0.32 μm, or 0.25 μm to 0.3 μm.
상기 필러의 D90은 0.25 ㎛ 내지 0.75 ㎛일 수 있다. 예를 들어, 상기 필러의 D90은 0.26 ㎛ 내지 0.65 ㎛, 0.28 ㎛ 내지 0.58 ㎛, 0.31 ㎛ 내지 0.52 ㎛, 0.35 ㎛ 내지 0.48 ㎛ 또는 0.36 ㎛ 내지 0.46 ㎛일 수 있다.D 90 of the filler may be 0.25 μm to 0.75 μm. For example, the D 90 of the filler may be 0.26 μm to 0.65 μm, 0.28 μm to 0.58 μm, 0.31 μm to 0.52 μm, 0.35 μm to 0.48 μm, or 0.36 μm to 0.46 μm.
필러의 D10, D50 및 D90이 각각 상기 범위를 만족함으로써, 표면조도를 더욱 효과적으로 제어할 수 있으면서 헤이즈를 감소시켜 투명성을 극대화할 수 있다.D 10 of the filler, When D 50 and D 90 respectively satisfy the above ranges, surface roughness can be more effectively controlled and haze can be reduced to maximize transparency.
상기 필러의 입경은 레이저 회절 입경 분포 측정법, 예를 들어 습식 레이저 회절식의 입경 분포 측정에 의해 측정될 수 있다.The particle diameter of the filler may be measured by a laser diffraction particle size distribution measurement method, for example, a wet laser diffraction particle size distribution measurement method.
구체적으로, 상기 필러 0.3 g을 이소프로필알코올 30 ml와 혼합하고 45 W의 출력에서 5분 동안 초음파 처리하여 분산액을 제조하고, 상기 분산액 중 필러의 입경 분포를 입경 분포 측정기로 측정할 수 있다. 이에 따라 얻어진 입경 분포에서 부피 기준으로 누적 50%의 입경을 D50으로 나타내었다.Specifically, 0.3 g of the filler is mixed with 30 ml of isopropyl alcohol and ultrasonicated for 5 minutes at a power of 45 W to prepare a dispersion, and the particle size distribution of the filler in the dispersion may be measured with a particle size distribution analyzer. In the particle size distribution thus obtained, the cumulative 50% particle size based on the volume was indicated as D 50 .
또한, 상기 폴리에스테르계 필름은 상기 필러를 500 ppm 내지 2,000 ppm으로 포함할 수 있다. 예를 들어, 상기 필러의 함량은 상기 폴리에스테르계 필름 총 중량을 기준으로 550 ppm 내지 2,000 ppm, 600 ppm 내지 2,000 ppm, 700 ppm 내지 1,500 ppm 또는 800 ppm 내지 1,300 ppm일 수 있다.In addition, the polyester film may include the filler in an amount of 500 ppm to 2,000 ppm. For example, the content of the filler may be 550 ppm to 2,000 ppm, 600 ppm to 2,000 ppm, 700 ppm to 1,500 ppm, or 800 ppm to 1,300 ppm based on the total weight of the polyester film.
필러의 함량이 상기 범위를 만족함으로써, 폴리에스테르계 필름의 표면조도 및 분산성을 용이하게 제어할 수 있고, 이로 인해 필름의 기계적 물성, 광학적 특성, 및 권취성과 같은 공정성을 더욱 향상시킬 수 있다. 구체적으로, 필러의 함량이 2,000 ppm을 초과하는 경우, 권취성과 같은 공정성은 향상시킬 수 있으나, 헤이즈가 매우 감소하여 투명성이 매우 저하되고, 분산성 문제가 발생하여 표면 특성이 좋지 않다. 또한, 필러의 함량이 500 ppm 미만인 경우, 폴리에스테르계 필름의 표면조도가 바람직한 범위를 벗어나는 것은 물론, 분산성 및 투명성은 저하되지 않으나 권취성의 향상 정도가 크지 않아 효과적인 공정성을 얻을 수 없다.When the content of the filler satisfies the above range, surface roughness and dispersibility of the polyester film can be easily controlled, and thus mechanical properties, optical properties, and fairness such as winding property of the film can be further improved. Specifically, when the content of the filler exceeds 2,000 ppm, fairness such as windability may be improved, but haze is greatly reduced, resulting in very low transparency and poor surface properties due to dispersibility problems. In addition, when the content of the filler is less than 500 ppm, the surface roughness of the polyester film is out of the preferred range, and the dispersibility and transparency are not lowered, but the degree of improvement in windability is not great, so effective processability cannot be obtained.
폴리에스테르계 필름의 제조 방법Manufacturing method of polyester film
다른 구현예에 따른 폴리에스테르계 필름의 제조 방법은 디올 및 디카르복실산이 공중합된 공중합 폴리에스테르계 수지와 필러를 혼합하여 수지 조성물을 제조하는 단계; 상기 수지 조성물을 용융압출하여 미연신 시트를 제조하는 단계; 상기 미연신 시트를 제 1 방향으로 1차 연신하고, 상기 제 1 방향과 수직한 제 2 방향으로 2차 연신하여 연신 시트를 제조하는 단계; 및 상기 연신 시트를 200℃ 내지 260℃에서 열고정하여 폴리에스테르계 필름을 제조하는 단계를 포함하고, 상기 폴리에스테르계 필름이 상기 식 1에 따른 Rd가 2.5 이하이다.A method for manufacturing a polyester-based film according to another embodiment includes preparing a resin composition by mixing a co-polyester-based resin in which diols and dicarboxylic acids are copolymerized with a filler; Melting and extruding the resin composition to prepare an unstretched sheet; preparing a stretched sheet by first stretching the unstretched sheet in a first direction and secondarily stretching the unstretched sheet in a second direction perpendicular to the first direction; and preparing a polyester-based film by heat-setting the stretched sheet at 200° C. to 260° C., wherein the polyester-based film has an R d of 2.5 or less according to Formula 1.
먼저, 디올 및 디카르복실산이 공중합된 공중합 폴리에스테르계 수지와 필러를 혼합하여 수지 조성물을 제조한다. First, a resin composition is prepared by mixing a co-polyester-based resin in which diols and dicarboxylic acids are copolymerized with a filler .
상기 공중합 폴리에스테르계 수지는 디올 및 디카르복실산이 에스테르 교환반응을 거친 후 중합되어 형성될 수 있다. 상기 디올, 디카르복실산 및 공중합 폴리에스테르계 수지에 대한 설명은 전술한 바와 같다. The co-polyester-based resin may be formed by polymerization after a diol and a dicarboxylic acid undergo transesterification. Descriptions of the diol, dicarboxylic acid, and co-polyester-based resin are as described above.
구체적으로, 디올 및 디카르복실산을 혼합하고, 에스테르 교환반응 촉매를 투입하여 에스테르 교환반응을 진행한 후, 중합 반응을 진행하여 공중합 폴리에스테르계 수지를 제조할 수 있다.Specifically, a copolymerized polyester-based resin may be prepared by mixing a diol and a dicarboxylic acid, performing an ester exchange reaction by introducing a transesterification catalyst, and then proceeding with a polymerization reaction.
상기 에스테르 교환 반응의 촉매는 아세트산 망간(manganese acetate tetrahydrate), 아세트산 칼슘 및 아세트산 아연으로 이루어진 군으로부터 선택된 1종 이상일 수 있다. 상기 에스테르 교환 반응의 촉매의 함량은 상기 디카르복실산의 총 중량을 기준으로 0.02 중량부 내지 0.2 중량부, 0.02 중량부 내지 0.1 중량부 또는 0.05 중량부 내지 0.1 중량부일 수 있다.The catalyst for the transesterification reaction may be at least one selected from the group consisting of manganese acetate tetrahydrate, calcium acetate, and zinc acetate. The amount of the transesterification catalyst may be 0.02 part by weight to 0.2 part by weight, 0.02 part by weight to 0.1 part by weight, or 0.05 part by weight to 0.1 part by weight based on the total weight of the dicarboxylic acid.
또한, 상기 중합 반응에서 칼륨 및 마그네슘으로 이루어진 군으로부터 선택된 1종 이상의 첨가제; 트리메틸포스페이트와 같은 안정화제; 및 티타늄이소프로폭사이드, 테트라프로필티타네이트, 테트라부틸티타네이트 또는 테트라이소프로필티타네이트와 같은 티타늄계, 게르마늄옥사이드, 게르마늄메톡사이드, 게르마늄에톡사이드, 테트라메틸게르마늄, 테트라에틸게르마늄 또는 게르마늄설파이드와 같은 게르마늄계, 또는 삼산화안티몬, 안티몬트리옥사이드, 안티몬아세테이트, 또는 안티몬트리에틸렌글리콜과 같은 안티몬계와 같은 중합 촉매를 선택적으로 첨가할 수 있다.In addition, at least one additive selected from the group consisting of potassium and magnesium in the polymerization reaction; stabilizers such as trimethylphosphate; And titanium, such as titanium isopropoxide, tetrapropyl titanate, tetrabutyl titanate or tetraisopropyl titanate, germanium oxide, germanium methoxide, germanium ethoxide, tetramethyl germanium, tetraethyl germanium or germanium sulfide and A polymerization catalyst such as germanium-based or antimony-based such as antimony trioxide, antimony trioxide, antimony acetate, or antimony triethylene glycol may optionally be added.
상기 중합 촉매의 함량은 상기 공중합 폴리에스테르 수지 총 중량을 기준으로 0.00001 중량% 내지 0.001 중량% 또는 0.00005 중량% 내지 0.0005 중량%일 수 있다. The content of the polymerization catalyst may be 0.00001 wt % to 0.001 wt % or 0.00005 wt % to 0.0005 wt % based on the total weight of the co-polyester resin.
상기에서 제조된 공중합 폴리에스테르계 수지에 필러를 투입하고 혼합하여 수지 조성물을 제조할 수 있다. 상기 필러에 대한 설명은 전술한 바와 같다. A resin composition may be prepared by adding and mixing a filler to the co-polyester-based resin prepared above. Description of the filler is as described above.
다른 구현예에 따르면, 상기 수지 조성물을 제조하는 단계는 공중합 폴리에스테르계 수지와 필러를 1차 혼합하는 단계, 원료 수지(base resin)에 상기 1차 혼합물을 2차 혼합하는 단계를 포함할 수 있다.According to another embodiment, the step of preparing the resin composition may include the step of first mixing the co-polyester-based resin and the filler, and the step of secondarily mixing the first mixture with a base resin. .
구체적으로, 상기 공중합 폴리에스테르계 수지와 필러를 1차 혼합하고, 상기 공중합 폴리에스테르계 수지와 성분 및 함량이 동일한 원료 수지를 추가로 사용함으로써 제조되는 폴리에스테르계 필름의 품질을 더욱 향상시킬 수 있다. Specifically, the quality of the polyester film produced by first mixing the co-polyester-based resin and the filler and additionally using a raw resin having the same components and contents as the co-polyester-based resin can be further improved. .
상기 원료 수지는 디올 및 디카르복실산을 포함할 수 있다. 구체적으로, 상기 원료 수지의 디올 및 디카르복실산은 상기 공중합 폴리에스테르계 수지의 디올 및 디카르복실산과 그 종류 및 함량이 동일할 수 있다. 상기 원료 수지와 상기 공중합 폴리에스테르계 수지의 성분 및 함량이 동일할 경우, 제조되는 폴리에스테르계 필름의 품질을 더욱 향상시킬 수 있다.The raw material resin may include a diol and a dicarboxylic acid. Specifically, the diol and dicarboxylic acid of the raw resin may have the same type and content as the diol and dicarboxylic acid of the co-polyester-based resin. When the components and contents of the raw material resin and the co-polyester-based resin are the same, the quality of the produced polyester-based film can be further improved.
상기 1차 혼합 단계는 95 중량% 이상의 공중합 폴리에스테르계 수지와 5 중량% 이하의 필러를 혼합할 수 있다. 예를 들어, 상기 1차 혼합 단계에서 투입되는 공중합 폴리에스테르계 수지의 함량은 95 중량% 이상 또는 97 중량% 이상일 수 있고, 95 중량% 내지 99.5 중량%, 95 중량% 내지 99 중량% 또는 97 중량% 내지 99 중량%일 수 있다. 또한, 상기 혼합 단계에서 투입되는 필러의 함량은 5 중량% 이하, 4 중량% 이하 또는 3 중량% 이하일 수 있고, 0.5 중량% 내지 5 중량%, 0.5 중량% 내지 4 중량% 또는 1 중량% 내지 3 중량%일 수 있다.In the first mixing step, 95% by weight or more of the co-polyester-based resin and 5% by weight or less of the filler may be mixed. For example, the content of the co-polyester-based resin added in the first mixing step may be 95% by weight or more or 97% by weight or more, 95% to 99.5% by weight, 95% to 99% by weight or 97% by weight. % to 99% by weight. In addition, the content of the filler added in the mixing step may be 5% by weight or less, 4% by weight or less, or 3% by weight or less, 0.5% to 5% by weight, 0.5% to 4% by weight, or 1% to 3% by weight. weight percent.
또한, 상기 2차 혼합 단계는 상기 1차 혼합물을 1 중량부 내지 10 중량부로 혼합할 수 있다. 예를 들어, 상기 2차 혼합 단계는 상기 원료 수지 90 중량부 내지 100 중량부, 93 중량부 내지 99 중량부 또는 93 중량부 내지 97 중량부에 상기 1차 혼합물을 1 중량부 내지 10 중량부, 1 중량부 내지 8 중량부, 1.5 중량부 내지 6 중량부 또는 2 중량부 내지 5 중량부로 투입하여 혼합할 수 있다.In the second mixing step, the first mixture may be mixed in an amount of 1 part by weight to 10 parts by weight. For example, in the second mixing step, 1 part by weight to 10 parts by weight, 1 part by weight to 8 parts by weight, 1.5 parts by weight to 6 parts by weight, or 2 parts by weight to 5 parts by weight may be introduced and mixed.
이후, 상기 수지 조성물을 용융압출하여 미연신 시트를 제조한다. Thereafter, the resin composition is melt-extruded to prepare an unstretched sheet .
구체적으로, 상기 혼합물 또는 2차 혼합물을 T-다이(T-die)로 용융압출한 후, 냉각시켜 미연신 시트를 제조할 수 있다. Specifically, after melting and extruding the mixture or secondary mixture with a T-die, cooling may be performed to prepare an unstretched sheet.
상기 용융압출 단계는 Tm+5℃ 내지 Tm+70℃, Tm+5℃ 내지 Tm+50℃ 또는 Tm+7℃ 내지 Tm+35℃의 온도에서 수행될 수 있고, 상기 냉각 단계는 Tg-120℃ 내지 Tg+20℃, Tg-110℃ 내지 Tg+10℃, Tg-105℃ 내지 Tg-30℃, Tg-105℃ 내지 Tg-50℃, Tg-105℃ 내지 Tg-65℃, Tg-105℃ 내지 Tg-80℃의 온도에서 수행될 수 있다.The melt-extruding step may be performed at a temperature of Tm+5°C to Tm+70°C, Tm+5°C to Tm+50°C or Tm+7°C to Tm+35°C, and the cooling step is Tg-120°C. to Tg+20℃, Tg-110℃ to Tg+10℃, Tg-105℃ to Tg-30℃, Tg-105℃ to Tg-50℃, Tg-105℃ to Tg-65℃, Tg-105℃ to Tg-80 °C.
예를 들어, 상기 용융압출 온도는 260℃ 내지 320℃, 270℃ 내지 310℃ 또는 270℃ 내지 295℃일 수 있고, 상기 냉각 온도는 -20℃ 내지 100℃, 0℃ 내지 90℃, 5℃ 내지 75℃, 10℃ 내지 60℃, 10℃ 내지 50℃ 또는 15℃ 내지 45℃일 수 있다. 용융압출 온도가 상기 범위를 만족함으로써, 용융이 원활하면서 압출물의 점도가 적절하게 유지될 수 있다.For example, the melt extrusion temperature may be 260 ° C to 320 ° C, 270 ° C to 310 ° C or 270 ° C to 295 ° C, and the cooling temperature may be -20 ° C to 100 ° C, 0 ° C to 90 ° C, 5 ° C to 75°C, 10°C to 60°C, 10°C to 50°C or 15°C to 45°C. When the melt-extrusion temperature satisfies the above range, the viscosity of the extrudate may be appropriately maintained while melting is smooth.
이후, 상기 미연신 시트를 제 1 방향으로 1차 연신하고, 상기 제 1 방향과 수직한 제 2 방향으로 2차 연신하여 연신 시트를 제조한다. Then, a stretched sheet is prepared by first stretching the unstretched sheet in a first direction and secondarily stretching it in a second direction perpendicular to the first direction.
상기 1차 연신은 60℃ 내지 120℃의 온도에서 2배 내지 5배의 연신율로 수행될 수 있다. 예를 들어, 상기 1차 연신 단계는 60℃ 내지 120℃, 70℃ 내지 110℃, 75℃ 내지 105℃, 80℃ 내지 100℃ 또는 85℃ 내지 100℃의 온도에서 2배 내지 5배, 2.5배 내지 4.5배, 2.5배 내지 4배 또는 2.9배 내지 3.5배의 연신율로 수행될 수 있다. 1차 연신의 온도 및 연신율이 상기 범위를 만족함으로써, 내열성, 내구성 및 내가수분해성을 향상시킬 수 있다.The primary stretching may be performed at a stretching rate of 2 to 5 times at a temperature of 60° C. to 120° C. For example, the first stretching step is 2 to 5 times, 2.5 times at a temperature of 60 ° C to 120 ° C, 70 ° C to 110 ° C, 75 ° C to 105 ° C, 80 ° C to 100 ° C or 85 ° C to 100 ° C. to 4.5 times, 2.5 times to 4 times, or 2.9 times to 3.5 times. When the temperature and elongation rate of the primary stretching satisfy the above ranges, heat resistance, durability and hydrolysis resistance can be improved.
상기 1차 연신 이후에 상기 제 1 방향과 수직한 제 2 방향으로 2차 연신한다. 상기 2차 연신은 2배 내지 5배의 연신율로 수행될 수 있다. 예를 들어, 상기 2차 연신은 70℃ 내지 140℃, 80℃ 내지 140℃, 90℃ 내지 135℃, 100℃ 내지 130℃ 또는 115℃ 내지 125℃의 온도에서 2배 내지 5배, 2.5배 내지 5배, 3배 내지 4.5배 또는 3.5배 내지 4.5배의 연신율로 수행될 수 있다. After the primary stretching, secondary stretching is performed in a second direction perpendicular to the first direction. The secondary stretching may be performed at a stretching rate of 2 to 5 times. For example, the secondary stretching is 2 to 5 times, 2.5 times to 2.5 times at a temperature of 70 ℃ to 140 ℃, 80 ℃ to 140 ℃, 90 ℃ to 135 ℃, 100 ℃ to 130 ℃ or 115 ℃ to 125 ℃. It may be performed at a stretch rate of 5x, 3x to 4.5x or 3.5x to 4.5x.
또한, 상기 2차 연신 이전에 예열 단계 또는 코팅 단계가 추가로 수행될 수 있다.In addition, a preheating step or a coating step may be additionally performed before the second stretching.
상기 예열 단계는 70℃ 내지 120℃에서 0.01 내지 1분 동안 수행될 수 있다. 예를 들어, 상기 예열 온도는 70℃ 내지 120℃, 75℃ 내지 115℃ 또는 80℃ 내지 110℃일 수 있고, 상기 예열 시간은 0.01 내지 1분, 0.05분 내지 0.5분, 0.08분 내지 0.2분일 수 있다.The preheating step may be performed at 70 °C to 120 °C for 0.01 to 1 minute. For example, the preheating temperature may be 70°C to 120°C, 75°C to 115°C, or 80°C to 110°C, and the preheating time may be 0.01 to 1 minute, 0.05 minutes to 0.5 minutes, or 0.08 minutes to 0.2 minutes. there is.
상기 코팅 단계는 폴리에스테르 필름에 대전방지 등과 같은 기능성을 부여할 수 있는 단계로서 스핀 코팅 또는 인라인 코팅으로 수행될 수 있으나 이에 한정되는 것은 아니다.The coating step is a step capable of imparting functionality such as antistatic to the polyester film, and may be performed by spin coating or in-line coating, but is not limited thereto.
상기 제 1 방향의 연신비(d1) 및 상기 제 2 방향의 연신비(d2)의 비율(d1/d2)은 0.5 내지 1일 수 있다. 예를 들어, 상기 제 1 방향의 연신비(d1) 및 상기 제 2 방향의 연신비(d2)의 비율(d1/d2)은 0.5 내지 0.95, 0.65 내지 0.95 또는 0.7 내지 0.9일 수 있다.A ratio (d1/d2) of the stretching ratio d1 in the first direction and the stretching ratio d2 in the second direction may be 0.5 to 1. For example, the ratio (d1/d2) of the stretching ratio d1 in the first direction and the stretching ratio d2 in the second direction may be 0.5 to 0.95, 0.65 to 0.95, or 0.7 to 0.9.
마지막으로, 상기 연신 시트를 200℃ 내지 260℃에서 열고정하여 폴리에스테르계 필름을 제조한다. Finally, the stretched sheet is heat-set at 200° C. to 260° C. to prepare a polyester-based film .
상기 열고정은 어닐링일 수 있고, 200℃ 내지 260℃에서 0.01분 내지 1분 동안 수행될 수 있다. 예를 들어, 상기 열고정 온도는 200℃ 내지 260℃, 210℃ 내지 250℃, 225℃ 내지 250℃ 또는 235℃ 내지 245℃일 수 있고, 상기 열고정 시간은 0.05분 내지 0.5분 또는 0.08분 내지 0.2분일 수 있으나, 이에 한정되는 것은 아니다. The heat setting may be annealing, and may be performed at 200° C. to 260° C. for 0.01 minute to 1 minute. For example, the heat setting temperature may be 200 ° C to 260 ° C, 210 ° C to 250 ° C, 225 ° C to 250 ° C, or 235 ° C to 245 ° C, and the heat setting time is 0.05 to 0.5 minutes or 0.08 minutes to 0.08 minutes. It may be 0.2 minutes, but is not limited thereto.
상기 열고정 이후에, 상기 열고정된 시트를 제 1 방향 또는 상기 제 1 방향과 수직한 제 2 방향으로 이완하는 단계를 추가로 수행할 수 있다.After the heat-setting, a step of relaxing the heat-set sheet in a first direction or in a second direction perpendicular to the first direction may be further performed.
또는, 상기 열고정 이후에, 상기 열고정된 시트를 제 1 방향으로 1차 이완한 후 제 2 방향으로 2차 이완하거나, 상기 열고정된 시트를 제 2 방향으로 1차 이완한 후 제 1 방향으로 2차 이완하는 단계를 추가로 수행할 수 있다. 예를 들어, 상기 열고정된 시트를 TD 방향으로 1차 이완한 후, MD 방향으로 2차 이완할 수 있다. Alternatively, after the heat setting, the heat-set sheet is firstly relaxed in a first direction and then secondarily relaxed in a second direction, or the heat-set sheet is firstly relaxed in a second direction and then the first direction A second relaxation step may be additionally performed. For example, the heat-set sheet may be first relaxed in the TD direction and then secondarily relaxed in the MD direction.
상기 열고정된 시트를 제 1 방향 또는 상기 제 1 방향과 수직한 제 2 방향으로 이완하는 경우, 상기 이완 단계는 100℃ 내지 180℃ 또는 110℃ 내지 175℃의 온도에서 0.5% 내지 5%, 0.8% 내지 4% 또는 0.8% 내지 3.5%의 이완율로 수행될 수 있다.When the heat-set sheet is relaxed in a first direction or in a second direction perpendicular to the first direction, the relaxation step is 0.5% to 5%, 0.8% at a temperature of 100 ° C to 180 ° C or 110 ° C to 175 ° C. % to 4% or 0.8% to 3.5% relaxation rate.
또한, 상기 이완 단계는 상기 제 2 방향으로 1% 내지 10%의 연신율로 1차 이완되고, 상기 제 1 방향으로 0.5% 이상 내지 2% 미만의 연신율로 2차 이완될 수 있다. 구체적으로, 상기 열고정된 시트를 1차 이완한 후 2차 이완하는 경우, 상기 1차 이완 단계는 150℃ 내지 200℃의 온도에서 0.5% 이상 내지 2% 미만의 이완율로 수행될 수 있고, 상기 2차 이완 단계는 110℃ 내지 190℃의 온도에서 0.5% 내지 5%의 이완율로 수행될 수 있다.In the relaxation step, the first relaxation may be performed at an elongation rate of 1% to 10% in the second direction, and the second relaxation may be performed at an elongation rate of 0.5% or more to less than 2% in the first direction. Specifically, when the second relaxation is performed after the first relaxation of the heat-set sheet, the first relaxation step may be performed at a relaxation rate of 0.5% or more to less than 2% at a temperature of 150 ° C to 200 ° C, The second relaxation step may be performed at a relaxation rate of 0.5% to 5% at a temperature of 110°C to 190°C.
예를 들어, 상기 1차 이완 단계는 150℃ 내지 200℃, 155℃ 내지 200℃, 160℃ 내지 180℃ 또는 165℃ 내지 175℃의 온도에서 1% 내지 10%, 1% 내지 9%, 1.5% 내지 8%, 1.5% 내지 7%, 2% 내지 6% 또는 2% 내지 5%의 이완율로 수행될 수 있고, 상기 2차 이완 단계는 110℃ 내지 190℃, 110℃ 내지 180℃, 110℃ 내지 170℃, 115℃ 내지 150℃, 115℃ 내지 140℃ 또는 115℃ 내지 130℃의 온도에서 0.5% 이상 내지 2% 미만, 0.5% 내지 1.95%, 0.7% 내지 1.8% 또는 0.9% 내지 1.6%의 이완율로 수행될 수 있다.For example, the first relaxation step is 1% to 10%, 1% to 9%, 1.5% at a temperature of 150 ° C to 200 ° C, 155 ° C to 200 ° C, 160 ° C to 180 ° C or 165 ° C to 175 ° C. to 8%, 1.5% to 7%, 2% to 6%, or 2% to 5% relaxation rate, and the second relaxation step is 110°C to 190°C, 110°C to 180°C, 110°C 0.5% to less than 2%, 0.5% to 1.95%, 0.7% to 1.8% or 0.9% to 1.6% at a temperature of from 170 ° C, 115 ° C to 150 ° C, 115 ° C to 140 ° C or 115 ° C to 130 ° C. It can be done with a relaxation rate.
1차 이완 단계 및 2차 이완 단계의 온도 및 이완율이 상기 범위를 만족함으로써, 내열성 및 내가수분해성을 향상시킬 수 있다. When the temperature and relaxation rate of the first relaxation step and the second relaxation step satisfy the above ranges, heat resistance and hydrolysis resistance may be improved.
또한, 상기 1차 이완율 : 상기 2차 이완율은 1 : 0.1 내지 1.0일 수 있다. 예를 들어, 상기 1차 이완율 : 상기 2차 이완율은 1 : 0.1 내지 0.9, 1 : 0.1 내지 0.8, 1 : 0.2 내지 0.7 또는 1 : 0.25 내지 0.65일 수 있다. 상기 1차 이완율 및 상기 2차 이완율의 비율이 상기 범위를 만족함으로써, 내열성 및 내가수분해성을 극대화할 수 있다.In addition, the first relaxation rate: the second relaxation rate may be 1:0.1 to 1.0. For example, the first relaxation rate: the second relaxation rate may be 1:0.1 to 0.9, 1:0.1 to 0.8, 1:0.2 to 0.7, or 1:0.25 to 0.65. When the ratio of the first relaxation rate and the second relaxation rate satisfies the above range, heat resistance and hydrolysis resistance may be maximized.
구체적으로, 상기 2차 이완 단계는 2구간 이상으로 나누어 수행될 수 있고, 상기 2차 이완율은 상기 각 구간의 이완율의 총 합일 수 있다. 예를 들어, 상기 2차 이완 단계가 4구간으로 나누어 수행되고, 상기 4구간의 이완율이 각각 순차적으로 0%, 0.5%, 0.5%, 1%로 수행되는 경우, 상기 2차 이완율은 2%이다. 2차 이완 단계를 상기와 같이 구간을 나누어 수행함으로써, 이완율의 조절이 더욱 용이하며 그에 따른 내열성 및 내가수분해성을 극대화할 수 있다.Specifically, the second relaxation step may be performed in two or more sections, and the second relaxation rate may be the total sum of the relaxation rates of each section. For example, when the second relaxation step is divided into 4 sections and the relaxation rates of the 4 sections are sequentially performed at 0%, 0.5%, 0.5%, and 1%, the second relaxation rate is 2 %am. By dividing the second relaxation step into sections as described above, the relaxation rate can be more easily controlled, and thus heat resistance and hydrolysis resistance can be maximized.
상기 2차 이완 단계에서 필름의 이송 속도는 상기 1차 이완 단계에서 필름의 이송 속도에 비하여 1% 내지 10% 느릴 수 있다. 예를 들어, 상기 2차 이완 단계에서 필름의 이송 속도는 상기 1차 이완 단계에서 필름의 이송 속도에 비하여 2% 내지 10% 또는 2% 내지 8% 느릴 수 있다.The transport speed of the film in the second relaxation step may be 1% to 10% slower than the transport speed of the film in the first relaxation step. For example, the transport speed of the film in the secondary relaxation step may be 2% to 10% or 2% to 8% slower than the transport speed of the film in the first relaxation step.
상기 내용을 하기 실시예에 의하여 더욱 상세하게 설명한다. 단, 하기 실시예는 본 발명을 예시하기 위한 것일 뿐, 실시예의 범위가 이들만으로 한정되는 것은 아니다.The above will be described in more detail by the following examples. However, the following examples are only for illustrating the present invention, and the scope of the examples is not limited only to these.
[실시예][Example]
공중합 폴리에스테르계 수지의 제조Preparation of co-polyester-based resin
제조예 1-1Preparation Example 1-1
디올로서 사이클로헥산디메탄올(CHDM) 100 몰%, 및 디카르복실산으로서 테레프탈산(TPA) 88 몰% 및 이소프탈산(IPA) 12 몰%을 교반기와 증류탑이 부착된 오토클레이브에 투입하고, 에스테르 교환반응 촉매로서 아세트산망간을 상기 디카르복실산 100 중량부를 기준으로 0.07 중량부로 투입한 후, 290℃까지 승온시키면서 에스테르 교환 반응을 진행하였다. 100 mol% of cyclohexanedimethanol (CHDM) as a diol, and 88 mol% of terephthalic acid (TPA) and 12 mol% of isophthalic acid (IPA) as dicarboxylic acids were put into an autoclave equipped with a stirrer and a distillation column, and transesterification After adding manganese acetate as a reaction catalyst in an amount of 0.07 parts by weight based on 100 parts by weight of the dicarboxylic acid, the transesterification reaction was performed while raising the temperature to 290 °C.
에스테르 교환 반응이 완료된 후, 중합 촉매로서 테트라부틸티타네이트를 상기 디카르복실산 100 중량부를 기준으로 0.0001 중량부를 투입하고 10분 동안 교반하였다. 이후, 상기 반응물을 진공 설비가 구비된 별도의 반응기로 이송한 후, 300℃에서 180분 동안 중합 반응을 진행하여 공중합 폴리에스테르계 수지(폴리사이클로헥산디메틸렌 테레프탈레이트(PCT) 수지)를 제조하였다.After the transesterification reaction was completed, 0.0001 parts by weight of tetrabutyl titanate based on 100 parts by weight of the dicarboxylic acid was added as a polymerization catalyst and stirred for 10 minutes. Thereafter, the reactants were transferred to a separate reactor equipped with a vacuum facility, and a polymerization reaction was performed at 300 ° C. for 180 minutes to prepare a copolymerized polyester-based resin (polycyclohexanedimethylene terephthalate (PCT) resin). .
수지 조성물의 제조Preparation of resin composition
제조예 2-1Preparation Example 2-1
상기 제조예 1-1에서 제조된 공중합 폴리에스테르계 수지 97.5 중량%와 필러로서 구상의 실리카 비드(Dsem: 0.3 ㎛) 2.5 중량%를 1차 혼합했다. 97.5% by weight of the co-polyester-based resin prepared in Preparation Example 1-1 and 2.5% by weight of spherical silica beads (D sem : 0.3 μm) as a filler were first mixed.
이후, 원료 수지(base resin) 96 중량부에 상기 1차 혼합물 4 중량부를 2차 혼합하여 수지 조성물을 제조했다. 이때, 상기 원료 수지는 디올로서 100 몰%의 사이클로헥산디메탄올(CHDM)을 포함했고, 디카르복실산으로서 96 몰%의 테레프탈산(TPA) 및 4 몰%의 이소프탈산(IPA)을 포함했다. 또한, 상기 2차 혼합하여 제조된 수지 조성물 내 실리카 비드의 함량은 1,000 ppm이었다.Thereafter, a resin composition was prepared by secondarily mixing 4 parts by weight of the primary mixture with 96 parts by weight of a base resin. At this time, the raw material resin contained 100 mol% of cyclohexanedimethanol (CHDM) as a diol, and 96 mol% of terephthalic acid (TPA) and 4 mol% of isophthalic acid (IPA) as dicarboxylic acids. In addition, the content of the silica beads in the resin composition prepared by the secondary mixing was 1,000 ppm.
제조예 2-2Preparation Example 2-2
괴상(blocky)의 실리카 비드(Dsem: 3.5 ㎛)를 사용한 것을 제외하고, 상기 제조예 2-1과 동일한 방법으로 수지 조성물을 제조하였다.A resin composition was prepared in the same manner as in Preparation Example 2-1, except that blocky silica beads (D sem : 3.5 μm) were used.
폴리에스테르계 필름의 제조Manufacture of polyester-based film
실시예 1Example 1
상기 제조예 2-1에서 제조된 수지 조성물을 압출기에 투입한 후, T-다이(T-Die)로 290℃에서 용융압출한 후 25℃의 캐스팅롤에서 냉각하여 미연신 시트를 제조했다. 이후, 상기 미연신 시트를 90℃에서 MD 방향으로 3.0배의 연신율로 1차 연신한 후, 90℃에서 0.1분 동안 예열하고, 120℃에서 TD 방향으로 4.0배의 연신율로 2차 연신하여 연신 시트를 제조했다. 이후, 상기 연신 시트를 240℃에서 0.1분 동안 열고정하여 두께가 25 ㎛인 폴리에스테르계 필름을 제조하였다.After putting the resin composition prepared in Preparation Example 2-1 into an extruder, melt-extruding at 290 ° C. with a T-Die and then cooling with a casting roll at 25 ° C. to prepare an unstretched sheet. Thereafter, the unstretched sheet is first stretched at 90° C. in the MD direction at a stretch rate of 3.0 times, preheated at 90° C. for 0.1 minute, and secondarily stretched at 120° C. in the TD direction at a stretch rate of 4.0 times. has manufactured Thereafter, the stretched sheet was heat-set at 240° C. for 0.1 minute to prepare a polyester-based film having a thickness of 25 μm.
실시예 2 및 3, 및 비교예 1 내지 3Examples 2 and 3, and Comparative Examples 1 to 3
하기 표 1과 같이 공정 조건을 적용한 것을 제외하고, 상기 실시예 1과 동일한 방법으로 폴리에스테르계 필름을 제조하였다.A polyester-based film was prepared in the same manner as in Example 1, except that process conditions were applied as shown in Table 1 below.
구분division 수지 조성물resin composition MD 연신율
(배)MD elongation
(ship) 		TD 연신율
(배)TD elongation
(ship) 		MD 연신
온도(℃)MD stretching
Temperature (℃) 		TD 연신
온도(℃)TD stretching
Temperature (℃) 		열고정
온도(℃)heat fixation
Temperature (℃)
실시예 1Example 1 제조예 2-1Preparation Example 2-1 3.03.0 4.04.0 9090 120120 240240
실시예 2Example 2 제조예 2-1Preparation Example 2-1 3.23.2 3.93.9 9090 120120 240240
실시예 3Example 3 제조예 2-1Preparation Example 2-1 3.43.4 4.04.0 9090 120120 240240
비교예 1Comparative Example 1 제조예 2-2Preparation Example 2-2 3.03.0 3.93.9 9090 120120 240240
비교예 2Comparative Example 2 제조예 2-2Preparation Example 2-2 3.23.2 4.04.0 9090 120120 240240
비교예 3Comparative Example 3 제조예 2-2Preparation Example 2-2 3.43.4 3.93.9 9090 120120 240240
[실험예][Experimental example]
실험예 1: 표면조도Experimental Example 1: Surface Roughness
상기 실시예 1 내지 3 및 비교예 1 내지 3에서 제조된 필름에 대하여, 2차원 접촉식 표면조도 측정기(Kosaka 사의 SE3300)을 이용하여 10점 평균 거칠기(Rz), 중심선 평균 거칠기(Ra) 및 최대 높이 거칠기(Rmax)를 측정하였다. 이때, 상기 필름의 CR면(제조시 롤에 안착되는 면) 및 상기 CR면의 타면인 비CR면에 대하여 각각 10점 평균 거칠기(Rz), 중심선 평균 거칠기(Ra) 및 최대 높이 거칠기(Rmax)를 측정하였다.With respect to the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3, 10-point average roughness (R z ) and center line average roughness (R a ) using a two-dimensional contact type surface roughness meter (SE3300 from Kosaka) and maximum height roughness (R max ) were measured. At this time, the 10-point average roughness (R z ), the center line average roughness (R a ) and the maximum height roughness ( R max ) was measured.
상기 10점 평균 거칠기(Rz)는 KS B 0161에 따른 표면조도로서, 먼저 상기 필름의 표면과 직각인 평면으로 표면을 절단하였을 때 그 절단면에 나타나는 일부 구간을 확대하여 기록한 단면곡선에서 기준길이만큼 채취하고, 상기 단면곡선의 평균선과 평행한 임의의 직선을 기준선으로 설정했다. 이때, 가장 높은 5개의 산에 대하여, 기준선으로부터의 거리에 대한 평균값과 가장 낮은 5개의 골에 대하여 기준선으로부터의 거리에 대한 평균값의 차이로 계산하였다.The 10-point average roughness (R z ) is a surface roughness according to KS B 0161, and when the surface is first cut with a plane perpendicular to the surface of the film, a section appearing on the cut surface is enlarged and recorded by a reference length in the cross-sectional curve was collected, and an arbitrary straight line parallel to the average line of the cross-sectional curve was set as the reference line. At this time, the difference between the average value of the distance from the baseline for the five highest peaks and the average value for the distance from the baseline for the five lowest valleys was calculated.
상기 중심선 평균 거칠기(Ra)는 KS B 0161에 따른 표면조도로서, 거칠기 곡선에서 산을 깎아 골을 메웠을 때 생기는 직선을 중심선이라 하며, 그 중심선의 방향으로 측정길이를 채취하고, 상기 중심선으로부터 아래쪽에 있는 부분을 위쪽으로 접어서 얻은 윗부분의 면적을 상기 측정길이로 나누어 계산하였다. The center line average roughness (R a ) is a surface roughness according to KS B 0161, and a straight line generated when a mountain is cut from a roughness curve to fill a valley is called a center line, and a measured length is taken in the direction of the center line, and from the center line It was calculated by dividing the area of the upper part obtained by folding the lower part upward by the measured length.
상기 최대 높이 거칠기(Rmax)는 KS B 0161에 따른 표면조도로서, 단면곡선에서 기준길이를 채취하고, 상기 단면곡선의 중심선과 평행하며 가장 높은 산과 가장 깊은 골을 접하는 두 평행선 간의 거리로 계산하였다. The maximum height roughness (R max ) is a surface roughness according to KS B 0161, a reference length is taken from a cross-sectional curve, and the distance between two parallel lines that are parallel to the center line of the cross-sectional curve and touch the highest peak and the deepest valley was calculated. .
또한, 하기 식 1에 따라 Rd를 계산하였다.In addition, R d was calculated according to Equation 1 below.
[식 1][Equation 1]
Figure PCTKR2022015165-appb-img-000005
Figure PCTKR2022015165-appb-img-000005
상기 식 1에 있어서,In the above formula 1,
Rmax는 폴리에스테르계 필름의 최대 높이 거칠기(㎛)이고, Ra는 폴리에스테르계 필름의 중심선 평균 거칠기(㎛)이다.R max is the maximum height roughness (μm) of the polyester-based film, and R a is the center line average roughness (μm) of the polyester-based film.
실험예 2: 마찰계수Experimental Example 2: Coefficient of Friction
상기 실시예 1 내지 3 및 비교예 1 내지 3에서 제조된 필름에 대하여, ASTM D1894에 따라, 마찰계수 측정기의 시험 테이블에 시편을 수평으로 위치한 후, 시험장비를 일정 변위 속도로 구동시켜 동마찰계수(Fd)와 정마찰계수(Fs)를 측정하였다.With respect to the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3, in accordance with ASTM D1894, after horizontally placing the specimen on the test table of the friction coefficient measuring instrument, the test equipment was driven at a constant displacement speed to measure the dynamic friction coefficient. (F d ) and static friction coefficient (F s ) were measured.
또한, 하기 식 2에 따라 RF를 계산하였다. In addition, RF was calculated according to Equation 2 below.
[식 2][Equation 2]
Figure PCTKR2022015165-appb-img-000006
Figure PCTKR2022015165-appb-img-000006
식 2에 있어서, In Equation 2,
Rmax는 폴리에스테르계 필름의 최대 높이 거칠기(㎛)이고, Fd는 폴리에스테르계 필름의 동마찰계수이다.R max is the maximum height roughness (μm) of the polyester-based film, and F d is the kinetic friction coefficient of the polyester-based film.
실험예 3: 인장강도Experimental Example 3: Tensile strength
상기 실시예 1 내지 3 및 비교예 1 내지 3에서 제조된 필름을 가로 150 mm 및 세로 100 mm 크기로 절단하여 샘플을 준비하고, ASTM D 882에 따라 상온에서 인스트론(INSTRON)사의 만능시험기(4206-001, 제조사: UTM)의 시험 속도 200 mm/min로 동일한 샘플에 대하여 인장강도를 3번 측정하여 그 평균값을 계산하였다.Samples were prepared by cutting the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 into a size of 150 mm in width and 100 mm in length, and in accordance with ASTM D 882, an INSTRON universal testing machine (4206 -001, manufacturer: UTM) at a test speed of 200 mm/min, the tensile strength was measured three times for the same sample, and the average value was calculated.
실험예 4: 파단신율Experimental Example 4: Elongation at break
상기 실시예 1 내지 3 및 비교예 1 내지 3에서 제조된 필름을 가로 150 mm 및 세로 100 mm 크기로 절단하여 샘플을 준비하고, ASTM D 882에 따라 상온에서 인스트론(INSTRON)사의 만능시험기(4206-001, 제조사: UTM)의 시험 속도 200 mm/min로 동일한 샘플에 대하여 파단신율을 3번 측정하여 그 평균값을 계산하였다.Samples were prepared by cutting the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 into a size of 150 mm in width and 100 mm in length, and in accordance with ASTM D 882, an INSTRON universal testing machine (4206 -001, manufacturer: UTM) at a test speed of 200 mm/min, the elongation at break was measured three times for the same sample, and the average value was calculated.
실험예 5: 모듈러스Experimental Example 5: Modulus
상기 실시예 1 내지 3 및 비교예 1 내지 3에서 제조된 필름에 대하여, KS B 5521에 따라 모듈러스를 측정하였다.Modulus of the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was measured according to KS B 5521.
실험예 6: 헤이즈Experimental Example 6: Haze
상기 실시예 1 내지 3 및 비교예 1 내지 3에서 제조된 필름에 대하여, 헤이즈미터(SEP-H, 제조사: Nihon Semitsu Kogaku)를 이용하여 헤이즈를 측정하였다. The haze of the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 was measured using a haze meter (SEP-H, manufactured by Nihon Semitsu Kogaku).
실험예 7: 광투과율Experimental Example 7: Light Transmittance
상기 실시예 1 내지 3 및 비교예 1 내지 3에서 제조된 필름에 대하여, UltraScan PRO(제조사: Hunterlab)를 이용하여, 380 nm에서의 광투과율을 측정하였다.For the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3, the light transmittance at 380 nm was measured using UltraScan PRO (manufacturer: Hunterlab).
실험예 8: 표면 관찰Experimental Example 8: Surface observation
주사전자현미경(Scanning electron microscope SEM)을 이용하여 상기 실시예 1 내지 3 및 비교예 1 내지 3에서 제조된 필름의 표면을 관찰하였다. The surfaces of the films prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were observed using a scanning electron microscope (SEM).
구체적으로, 도 1 내지 3은 실시예 1 내지 3의 폴리에스테르계 필름의 주사전자현미경(SEM) 이미지를 나타낸 것이고, 도 4 내지 6은 비교예 1 내지 3의 폴리에스테르계 필름의 주사전자현미경(SEM) 이미지를 나타낸 것이다. Specifically, FIGS. 1 to 3 show scanning electron microscope (SEM) images of the polyester films of Examples 1 to 3, and FIGS. 4 to 6 are scanning electron microscope images of the polyester films of Comparative Examples 1 to 3 ( SEM) images are shown.
도 1 내지 6에서 보는 바와 같이, 실시예 1 내지 3의 폴리에스테르계 필름은 비교예 1 내지 3의 필름에 비하여 분산성이 우수하여 표면 특성이 우수하면서 표면조도가 효과적으로 제어되었음을 확인하였다.As shown in FIGS. 1 to 6, it was confirmed that the polyester films of Examples 1 to 3 had better dispersibility than the films of Comparative Examples 1 to 3, so that the surface roughness was effectively controlled while having excellent surface properties.
구분division 실시예 1Example 1 실시예 2Example 2 실시예 3Example 3 비교예 1Comparative Example 1 비교예 2Comparative Example 2 비교예 3Comparative Example 3
표면조도
(CR, ㎛)surface roughness
(CR, μm) 		Rz R z 0.1700.170 0.2000.200 1.0001.000 0.8300.830 1.4201.420 0.2800.280
Ra R a 0.0080.008 0.0120.012 0.0570.057 0.0570.057 0.0580.058 0.0150.015
Rmax R max 0.8030.803 0.9030.903 1.8351.835 2.0632.063 1.9701.970 0.9610.961
Rd R d 0.9960.996 1.3291.329 3.1063.106 2.7632.763 2.9442.944 1.5611.561
표면조도
(비 CR, ㎛)surface roughness
(Ratio CR, μm) 		Rz R z 0.2400.240 0.2400.240 1.1201.120 0.8800.880 1.3601.360 0.2700.270
Ra R a 0.0130.013 0.0110.011 0.0530.053 0.0640.064 0.0630.063 0.0120.012
Rmax R max 0.8890.889 0.5730.573 1.6441.644 1.8761.876 1.9161.916 0.6000.600
마찰계수friction coefficient Fd F d 0.480.48 0.530.53 0.440.44 0.430.43 0.420.42 0.540.54
Fs F s 0.620.62 0.630.63 0.570.57 0.540.54 0.540.54 0.670.67
RFRF 0.390.39 0.480.48 0.810.81 0.890.89 0.830.83 0.520.52
인장강도
(kg/mm2)tensile strength
(kg/mm 2 ) 		MDMD 12.0712.07 14.3214.32 12.2612.26 11.2411.24 12.0812.08 14.8414.84
TDTD 14.5214.52 18.1318.13 13.6713.67 14.6914.69 13.5013.50 18.4218.42
파단신율
(%)Elongation at break
(%) 		MDMD 49.0249.02 55.7755.77 57.1257.12 42.0242.02 32.8532.85 42.9742.97
TDTD 34.6634.66 57.4457.44 34.4934.49 46.1746.17 32.7132.71 49.1949.19
모듈러스
(kg/mm2)modulus
(kg/mm 2 ) 		MDMD 261.03261.03 281.49281.49 248.89248.89 241.18241.18 253.81253.81 285.30285.30
TDTD 284.61284.61 292.23292.23 273.91273.91 261.00261.00 262.41262.41 298.59298.59
헤이즈(%)Haze (%) 3.503.50 3.073.07 4.364.36 9.039.03 8.258.25 9.749.74
광투과율(%)Light transmittance (%) 89.9689.96 89.9689.96 90.0690.06 90.6190.61 90.3690.36 90.4090.40
상기 표 2에서 보는 바와 같이, 실시예 1 내지 3의 폴리에스테르계 필름은 비교예 1 내지 3의 필름에 비하여 광학적 특성 및 기계적 물성이 모두 우수한 결과를 나타내었다. As shown in Table 2, the polyester films of Examples 1 to 3 exhibited superior optical properties and mechanical properties compared to the films of Comparative Examples 1 to 3.
구체적으로, 실시예 1 내지 3의 폴리에스테르계 필름은 10점 평균 거칠기(Rz), 중심선 평균 거칠기(Ra) 및 최대 높이 거칠기(Rmax)가 모두 특정 범위로 제어됨으로써 마찰계수, 인장강도, 파단신율 및 모듈러스와 같은 기계적 물성이 저하되지 않으면서 헤이즈 및 광투과율과 같은 광학적 특성이 모두 우수했다. Specifically, in the polyester films of Examples 1 to 3, the 10-point average roughness (R z ), the center line average roughness (R a ), and the maximum height roughness (R max ) are all controlled within a specific range, thereby increasing the friction coefficient and tensile strength. , optical properties such as haze and light transmittance were all excellent without degradation of mechanical properties such as elongation at break and modulus.
반면, 비교예 1 내지 3의 필름은 10점 평균 거칠기(Rz), 중심선 평균 거칠기(Ra) 및 최대 높이 거칠기(Rmax)가 바람직한 범위를 만족하지 못하여 헤이즈 및 광투과율과 같은 광학적 특성이 저하되었다.On the other hand, in the films of Comparative Examples 1 to 3, the 10-point average roughness (R z ), the center line average roughness (R a ), and the maximum height roughness (R max ) do not satisfy desirable ranges, and thus have poor optical properties such as haze and light transmittance. has been lowered

Claims (12)

  1. 디올 및 2종 이상의 디카르복실산이 공중합된 공중합 폴리에스테르계 수지; 및 필러를 포함하고, co-polyester-based resins obtained by copolymerization of diols and two or more types of dicarboxylic acids; and a filler;
    하기 식 1에 따른 Rd가 2.5 이하인, 폴리에스테르계 필름:R d according to the following formula 1 is 2.5 or less, a polyester-based film:
    [식 1][Equation 1]
    Figure PCTKR2022015165-appb-img-000007
    Figure PCTKR2022015165-appb-img-000007
    상기 식 1에 있어서,In the above formula 1,
    Rmax는 폴리에스테르계 필름의 최대 높이 거칠기(㎛)이고, R max is the maximum height roughness (μm) of the polyester film,
    Ra는 폴리에스테르계 필름의 중심선 평균 거칠기(㎛)이다.R a is the center line average roughness (μm) of the polyester-based film.
  2. 제 1 항에 있어서,According to claim 1,
    10점 평균 거칠기(Rz)가 0.8 ㎛ 이하이고, The 10-point average roughness (Rz) is 0.8 μm or less,
    중심선 평균 거칠기(Ra)가 0.05 ㎛ 이하이고, The center line average roughness (Ra) is 0.05 μm or less,
    최대 높이 거칠기(Rmax)가 1.5 ㎛ 이하인, 폴리에스테르계 필름.A polyester-based film having a maximum height roughness (Rmax) of 1.5 μm or less.
  3. 제 1 항에 있어서,According to claim 1,
    10점 평균 거칠기(Rz)가 0.3 ㎛ 이하인, 폴리에스테르계 필름.A polyester-based film having a 10-point average roughness (Rz) of 0.3 μm or less.
  4. 제 1 항에 있어서,According to claim 1,
    상기 필러가 이산화티탄, 황산바륨, 탄산칼슘, 탄산마그네슘, 탄산아연, 산화아연, 산화마그네슘, 알루미나, 및 실리카로 이루어진 군으로부터 선택된 1종 이상을 포함하고,The filler includes at least one selected from the group consisting of titanium dioxide, barium sulfate, calcium carbonate, magnesium carbonate, zinc carbonate, zinc oxide, magnesium oxide, alumina, and silica,
    상기 필러의 평균 입경(Dsem)이 0.01 ㎛ 내지 2.0 ㎛인, 폴리에스테르계 필름.The average particle diameter (D sem ) of the filler is 0.01 μm to 2.0 μm, a polyester-based film.
  5. 제 4 항에 있어서,According to claim 4,
    상기 필러가 구 형상의 실리카 비드인, 폴리에스테르계 필름.The filler is a spherical silica bead, a polyester-based film.
  6. 제 1 항에 있어서,According to claim 1,
    상기 폴리에스테르계 필름 총 중량을 기준으로 상기 필러를 500 ppm 내지 2,000 ppm으로 포함하는, 폴리에스테르계 필름.A polyester-based film comprising 500 ppm to 2,000 ppm of the filler based on the total weight of the polyester-based film.
  7. 제 1 항에 있어서,According to claim 1,
    하기 식 2에 따른 RF가 0.8 이하인, 폴리에스테르계 필름:A polyester-based film having an RF of 0.8 or less according to the following formula 2:
    [식 2][Equation 2]
    Figure PCTKR2022015165-appb-img-000008
    Figure PCTKR2022015165-appb-img-000008
    식 2에 있어서, In Equation 2,
    Rmax는 폴리에스테르계 필름의 최대 높이 거칠기(㎛)이고, R max is the maximum height roughness (μm) of the polyester film,
    Fd는 폴리에스테르계 필름의 동마찰계수이다.F d is the coefficient of kinetic friction of the polyester film.
  8. 제 7 항에 있어서,According to claim 7,
    동마찰계수(Fd)가 0.6 이하이고, The dynamic friction coefficient (F d ) is 0.6 or less,
    정마찰계수(Fs)가 0.75 이하인, 폴리에스테르계 필름.A static friction coefficient (F s ) of 0.75 or less, a polyester-based film.
  9. 제 1 항에 있어서,According to claim 1,
    헤이즈가 8% 이하이고, Haze is 8% or less,
    380 nm 파장에서의 투과율이 88% 이상인, 폴리에스테르계 필름.A polyester-based film having a transmittance of 88% or more at a wavelength of 380 nm.
  10. 제 1 항에 있어서,According to claim 1,
    인장강도가 19 kgf/mm2 이하이고, Tensile strength is 19 kgf / mm 2 or less,
    파단신율이 30% 이상이고, The elongation at break is 30% or more,
    모듈러스가 320 kgf/mm2 이하인, 폴리에스테르계 필름.A polyester-based film having a modulus of 320 kgf/mm 2 or less.
  11. 제 1 항에 있어서,According to claim 1,
    상기 디올이 1,4-시클로헥산디메탄올 또는 이의 유도체를 포함하고,The diol includes 1,4-cyclohexanedimethanol or a derivative thereof,
    상기 2종 이상의 디카르복실산이 70 몰% 내지 99 몰%의 테레프탈산 및 1 몰% 내지 30 몰%의 이소프탈산을 포함하는, 폴리에스테르계 필름.A polyester-based film, wherein the two or more dicarboxylic acids include 70 mol% to 99 mol% of terephthalic acid and 1 mol% to 30 mol% of isophthalic acid.
  12. 디올 및 디카르복실산이 공중합된 공중합 폴리에스테르계 수지와 필러를 혼합하여 수지 조성물을 제조하는 단계;preparing a resin composition by mixing a co-polyester-based resin in which diols and dicarboxylic acids are copolymerized with a filler;
    상기 수지 조성물을 용융압출하여 미연신 시트를 제조하는 단계;Melting and extruding the resin composition to prepare an unstretched sheet;
    상기 미연신 시트를 제 1 방향으로 1차 연신하고, 상기 제 1 방향과 수직한 제 2 방향으로 2차 연신하여 연신 시트를 제조하는 단계; 및preparing a stretched sheet by first stretching the unstretched sheet in a first direction and secondarily stretching the unstretched sheet in a second direction perpendicular to the first direction; and
    상기 연신 시트를 200℃ 내지 260℃에서 열고정하여 폴리에스테르계 필름을 제조하는 단계를 포함하고, Heat-setting the stretched sheet at 200 ° C to 260 ° C to prepare a polyester-based film,
    상기 폴리에스테르계 필름이 하기 식 1에 따른 Rd가 2.5 이하인, 폴리에스테르계 필름의 제조 방법:Method for producing a polyester-based film wherein the polyester-based film has R d of 2.5 or less according to the following formula 1:
    [식 1][Equation 1]
    Figure PCTKR2022015165-appb-img-000009
    Figure PCTKR2022015165-appb-img-000009
    상기 식 1에 있어서,In the above formula 1,
    Rmax는 폴리에스테르계 필름의 최대 높이 거칠기(㎛)이고, R max is the maximum height roughness (μm) of the polyester film,
    Ra는 폴리에스테르계 필름의 중심선 평균 거칠기(㎛)이다.R a is the center line average roughness (μm) of the polyester-based film.
PCT/KR2022/015165 2021-12-03 2022-10-07 Polyester-based film and production method therefor WO2023101191A1 (en)

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US6372326B1 (en) * 1998-04-13 2002-04-16 Teijin Limited Biaxially oriented polyester film to be molded and laminated on metal sheet
KR20150075471A (en) * 2013-12-26 2015-07-06 코오롱인더스트리 주식회사 Polyester resin composition and polyester film using thereof
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KR100656246B1 (en) 2004-11-30 2006-12-11 한국화학연구원 Manufacturing method of flexible copper clad laminate using surface modification of polyimide film and its product thereby
KR102320808B1 (en) * 2017-12-29 2021-11-01 코오롱인더스트리 주식회사 Heat shrinkable Polyester white film, Method of manufacturing thereof and Label comprising thereof

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US4939232A (en) * 1988-07-05 1990-07-03 Diafoil Company, Ltd. Shrinkable polyester film
US6372326B1 (en) * 1998-04-13 2002-04-16 Teijin Limited Biaxially oriented polyester film to be molded and laminated on metal sheet
KR20150075471A (en) * 2013-12-26 2015-07-06 코오롱인더스트리 주식회사 Polyester resin composition and polyester film using thereof
KR20150094992A (en) * 2014-02-12 2015-08-20 에스케이씨 주식회사 Polyester film having high heat resistance
KR20170080025A (en) * 2015-12-31 2017-07-10 코오롱인더스트리 주식회사 Polycyclohexylenedimethylene terephthalate film and manufacturing method thereof

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