KR102510619B1 - Biaxially oriented polyester matted film and manufacturing method thereof - Google Patents

Abstract

The present invention includes a biaxially stretched polyester base film and a coating layer applied with a coating composition on at least one surface of the polyester base film, wherein the coating layer includes a co-polyester resin (A) and an incompatible resin (B), 1 is satisfied, (Equation 1) 0.0001 ≤ t _P / _tS ≤ 0.01, where _tS Is the thickness of the base film, and t _P is the thickness of the coating layer. It relates to a biaxially stretched polyester matte film, which has low gloss, excellent transparency, and excellent film formation stability, and is laminated with or transferred to various packaging films or decorative films. Matte characteristics can be imparted to the surface of the film.

Description

Biaxially stretched polyester matte film and manufacturing method thereof

The present invention relates to a biaxially stretched polyester matte film and a method for producing the same, and more specifically, has low gloss, excellent transparency, and excellent film forming stability, and is laminated with or transferred to various packaging films or decorative films to form a matte surface on the film surface. It relates to a biaxially stretched polyester matte film capable of imparting characteristics and a method for manufacturing the same.

In general, biaxially stretched polyester films have excellent mechanical properties, thermal properties, chemical resistance properties and transparency, and are widely used in various fields such as various packaging materials, industrial materials, and optical films for displays.

Among them, the biaxially stretched polyester matte film with matte surface characteristics is used for bonding or transferring various packaging films or decorative films, and to increase the marketability of packaging materials or decorative materials by imparting matte characteristics to the surface of the film. is being used a lot.

Conventional biaxially stretched polyester matte films have been given matte properties by adding a large amount of inorganic particles such as silica to the inside of the film to increase the film surface roughness. In the case of this technology, since matte properties are realized only when a large amount of particles are added to the inside of the film, the stretching properties are significantly lowered in the biaxial stretching film forming process, resulting in a number of film breaks, and the biaxial stretching produced by adding a large amount of particles. There is a problem that the transparency of the polyester film is significantly lowered.

In order to solve the problem of such a biaxially stretched polyester matte film, Korean Patent Publication No. 10-2002-0039227 proposes a matte film in an A/B/A or A/B laminated structure using a co-extrusion process. However, it was confirmed that there are limitations in securing film formation stability and high transparency of the film.

Korean Patent Publication No. 10-2002-0039227

The present invention has been made to solve the above-mentioned problems, and the problem to be solved by the present invention is low gloss, excellent transparency, and excellent film forming stability, and is laminated with various packaging films or decorative films or transferred to the film surface. It is to provide a biaxially stretched polyester matte film capable of imparting matte properties to and a manufacturing method thereof.

The above and other objects and advantages of the present invention will become apparent from the following description of preferred embodiments.

The above object includes a biaxially stretched polyester base film and a coating layer applied with a coating composition on at least one surface of the polyester base film, wherein the coating layer includes a co-polyester resin (A) and an incompatible resin (B), Satisfy Equation 1 below,

(Equation 1) 0.0001 ≤ t _P / t _S ≤ 0.01

Here, t _S is the thickness of the base film and t _P is the thickness of the coating layer.

Preferably, the biaxially stretched polyester matte film simultaneously satisfies the following formulas 2 and 3,

(Equation 2) Tg _S -50 ° C ≤ Tg _A ≤ Tg _S

(Equation 3) Tc _S +30°C ≤ Tg _B ≤ Tc _S +100°C

Here, Tg _A may be the glass transition temperature of the co-polyester resin (A), Tg _B may be the glass transition temperature of the incompatible resin, Tg _S may be the glass transition temperature of the base film, and Tc _S may be the crystallization temperature of the base film.

Preferably, the coating composition may include 51 to 90% by weight of the co-polyester resin (A) and 10 to 49% by weight of the incompatible resin (B) in the total solid content.

Preferably, the copolymerized polyester resin (A) contains at least one of dimethyl terephthalate, terephthalic acid, isophthalic acid and 1,4-cyclohexanedicarboxylic acid as an aromatic dicarboxylic acid component and ethylene glycol and trimethylene as a diol component. It may be a resin copolymerized with at least one of glycol, tetramethylene glycol, 2,2-dimethyl(1,3-propane)diol, and 1,4-cyclohexanedimethanol.

Preferably, the incompatible resin (B) is selected from crystalline polyolefin resins, amorphous cyclic olefin resins, polystyrene resins, polyacrylate resins, polycarbonate resins, polyacrylonitrile resins, polyethylene sulfide resins and fluorine-based resins. It may be at least one or a homopolymer or copolymer thereof.

Preferably, the total thickness of the biaxially stretched polyester matte film may be 12 to 250 μm.

Preferably, the biaxially stretched polyester matte film may have a surface gloss of less than 50%.

Preferably, the biaxially oriented polyester matte film may have a haze of less than 10%.

Preferably, the biaxially stretched polyester matte film may have a total light transmittance of 85% or more.

Preferably, in the process of phase separation and transverse stretching of the co-polyester resin (A) and the incompatible resin (B), the incompatible resin (B) may be formed into particles to have a matte property.

In addition, the above object is achieved by the above-described biaxially oriented polyester matte film, which is used for laminating or transferring to a packaging film or decorative film to impart matte properties to the surface of these films. do.

In addition, the above object is a first step of manufacturing a non-stretched sheet by melting and extruding polyester chips, followed by cooling and solidification, and a second step of preparing a uniaxially stretched base film by stretching the non-stretched sheet in the machine direction, A third step of forming a coating layer on the uniaxially stretched base film using a coating composition in which a co-polyester resin (A) and an incompatible resin (B) are mixed, and biaxially stretching the base film on which the coating layer is formed in the transverse direction It is achieved by a method for producing a biaxially stretched polyester matte film comprising a fourth step of doing and a fifth step of heat-treating the biaxially stretched film to produce a biaxially stretched polyester matte film.

Preferably, the fourth step may be a phase separation of the co-polyester resin (A) and the incompatible resin (B) and a step of imparting a matte property by converting the incompatible resin (B) into particles.

Preferably, the coating composition may include 51 to 90% by weight of the co-polyester resin (A) and 10 to 49% by weight of the incompatible resin (B) in the total solid content.

According to the biaxially stretched polyester matte film according to the present invention, there are effects such as low gloss, excellent transparency, and excellent film forming stability.

In addition, according to the present invention, by implementing a matte property in the coating layer of the thin film, there is an effect such that it can be used for laminating or transferring to various packaging films or decorative films to impart a matte property to the surface of the film.

However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a configuration diagram of a biaxially oriented polyester matte film according to an aspect of the present invention.

With reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In the drawings, the thickness is shown enlarged to clearly express the various layers and regions. Like reference numerals have been assigned to like parts throughout the specification. When a part such as a layer, film, region, plate, etc. is said to be “on” another part, this includes not only the case where it is “directly on” the other part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control. Also, although methods and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention, suitable methods and materials are described herein.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of a biaxially oriented polyester matte film according to an aspect of the present invention. Referring to FIG. 1, a biaxially stretched polyester matte film according to an aspect of the present invention includes a biaxially stretched polyester base film 1 and a coating layer applied with a coating composition on at least one surface of the polyester base film, the coating layer contains a silver co-polyester resin (A) (2) and an incompatible resin (B) (3). The coating layer is preferably a matte coating layer.

In one embodiment, the biaxially oriented polyester matte film satisfies the following formula 1,

(Equation 1)

0.0001 ≤ t _P / t _S ≤ 0.01

Here, t _S is the thickness of the biaxially stretched polyester base film, and t _P is the thickness of the coating layer.

At this time, when t _P / t _S , which represents the ratio of the thickness of the base film (t _S ) and the thickness of the coating layer (t _P ), is less than 0.0001, the thickness of the coating layer is too thin to achieve the required glossiness of the biaxially stretched polyester matte film. , If it exceeds 0.01, the thickness of the coating layer in the aqueous solution state applied after longitudinal stretching is too thick, resulting in frequent breakage of the film during lateral stretching. Since there is, it is preferable to set it as the above range.

In one embodiment, the biaxially stretched polyester matte film satisfies Equations 2 and 3 at the same time,

(Equation 2)

Tg _S -50℃ ≤ Tg _A ≤ Tg _S

(Equation 3)

Tc _S +30°C ≤ Tg _B ≤ Tc _S +100°C

Here, Tg _A is the glass transition temperature of the co-polyester resin (A), Tg _B is the glass transition temperature of the incompatible resin, Tg _S is the glass transition temperature of the base film and Tc _S is the crystallization temperature of the base film.

The coating layer of the biaxially stretched polyester matte film according to the present invention is composed of a co-polyester resin (A) and an incompatible resin (B), and as shown in FIG. 1, the co-polyester resin (A) is formed by phase separation of the different resins A matrix is formed, and the incompatible resin (B) forms a domain.

At this time, when the glass transition temperature (Tg _A ) of the co-polyester resin (A) in Equation 2 is smaller than the glass transition temperature of the base film -50 ° C (Tg _S -50 ° C), the co-polyester forming the matrix of the coating layer Since the resin (A) is soft at room temperature, there is a problem that coating defects such as scratches frequently occur due to friction with the roll during the film forming process, and the durability of the coating layer is significantly reduced, such as damage such as stamping on the coating layer even with a small external impact. In addition, when the glass transition temperature (Tg _A ) of the co-polyester resin (A) is greater than the glass transition temperature (Tg _S ) of the base film, the co-polymer poly forming the matrix of the coating layer in the stretching temperature range of the base film. The ester resin may not be sufficiently stretched, and cracks or white turbidity may occur in the coating layer, thereby reducing transparency or deteriorating the appearance of the coating.

In addition, in Equation 3, when the glass transition temperature (Tg _B ) of the incompatible resin (B) is less than the crystallization temperature of the base film + 30 ° C (Tc _S + 30 ° C), after stretching the base film, In the heat treatment process performed at the crystallization temperature of the base film + 30 ° C to 100 ° C to impart dimensional stability, the incompatible resin (B) forming the domain of the coating layer undergoes shape deformation by heat, so that the glossiness significantly increases. If there is a problem, and the glass transition temperature (Tg B ) of the incompatible resin ( _B ) is greater than the crystallization temperature of the base film + 100 ° C (Tc _S + 100 ° C), the co-polyester resin (A) and the incompatible resin It is difficult to implement uniform gloss properties due to poor dispersibility of (B), and incompatible resins having a high glass transition temperature have a problem in that manufacturing costs increase.

In one embodiment, the coating composition preferably includes 51 to 90% by weight of the co-polyester resin (A) and 10 to 49% by weight of the incompatible resin (B), based on the total solid content. At this time, if the content of the co-polyester resin (A) is less than 51% by weight or the content of the incompatible resin (B) exceeds 49% by weight, the matrix and the domain cannot be formed during phase separation of the different resins, or the matrix The co-polyester resin (A), which should form a domain, forms a domain, and the incompatible resin (B), which should form a domain, forms a matrix, so that the opposite phase separation phenomenon is realized, so that desired gloss characteristics can be realized. In addition, when the content of the co-polyester resin (A) exceeds 90% by weight or the content of the incompatible resin (B) is less than 10% by weight, the content of the incompatible resin (B) to form the domain is Since the number of incompatible resins (B) granulated in the coating layer is too low, the desired gloss characteristics cannot be realized.

In one embodiment, the co-polyester resin (A) includes at least one of dimethyl terephthalate, terephthalic acid, isophthalic acid, and 1,4-cyclohexanedicarboxylic acid as an aromatic dicarboxylic acid component and ethylene glycol or triglyceride as a diol component. It is preferably a resin copolymerized with at least one of methylene glycol, tetramethylene glycol, 2,2-dimethyl(1,3-propane)diol and 1,4-cyclohexanedimethanol.

In one embodiment, the incompatible resin (B) is a co-polyester resin (A) and a resin incompatible, crystalline polyolefin resin, amorphous cyclic olefin resin, polystyrene resin, polyacrylate resin, polycarbonate resin, polyacrylic It is preferably at least one selected from a ronitrile resin, a poly(ethylene sulfide) resin, and a fluorine-based resin, or a homopolymer or copolymer thereof.

In addition, since the co-polyester resin (A) and the incompatible resin (B) in the coating layer constituting the present invention proceed with water-based or solvent-based coating, it is preferable to form an emulsion in water or a solvent.

In one embodiment, the total thickness of the biaxially oriented polyester matte film is preferably 12 to 250 μm. When the total thickness is less than 12㎛, when a thick film coating layer of 0.1㎛ or more is applied, there are problems such as film breakage and poor film formation stability. If the thickness exceeds 250㎛, when the matte film is used for lamination or transfer, the thickness of the packaging or decorative material becomes too thick, resulting in poor processability and efficiency, and a problem in that the manufacturing cost based on the area of the film increases rapidly.

In one embodiment, the biaxially oriented polyester matte film preferably has a surface gloss of less than 50%.

In one embodiment, the biaxially oriented polyester matte film preferably has a haze of less than 10%.

In one embodiment, the biaxially stretched polyester matte film preferably has a total light transmittance of 85% or more.

In one embodiment, in the process of phase separation and transverse stretching of the co-polyester resin (A) and the incompatible resin (B), the incompatible resin (B) is preferably made into particles to have a matte property.

The biaxially oriented polyester matte film according to another aspect of the present invention is the above-described biaxially oriented polyester matte film, which is used for laminating or transferring to a packaging film or decorative film to impart a matte property to the surface of these films. It is a stretched polyester matte film.

Method for producing a biaxially stretched polyester matte film according to another aspect of the present invention is a first step of preparing a non-stretched sheet by melting and extruding polyester chips, followed by cooling and solidification, and stretching the non-stretched sheet in the longitudinal direction A second step of preparing a uniaxially stretched base film, and a third step of forming a coating layer on the uniaxially stretched base film using a coating composition in which a co-polyester resin (A) and an incompatible resin (B) are mixed. , a fourth step of transversely biaxially stretching the base film on which the coating layer is formed, and a fifth step of preparing a biaxially stretched polyester matte film by heat-treating the biaxially stretched film.

More specifically, in the first step, a polyethylene terephthalate resin having an intrinsic viscosity (IV) of 0.65 is dried under high vacuum to remove moisture present in the resin, and then supplied to an extruder heated at a temperature of 260 to 300 ° C. After melting and extruding, This step is to prepare a non-stretched sheet that is cooled and solidified by using a casting or calendering method after being introduced into a T-die die.

The second step is a step in which the non-stretched sheet obtained in the first step is passed through a roll preheated to 80 to 120 ° C., and then longitudinally stretched 2 to 5 times in the machine direction using a difference in peripheral speed ratio of the rolls.

The third step is to apply a coating composition in which a copolymerized polyester resin (A) and an incompatible resin (B) are mixed to a wet thickness of several to several tens of μm in an in-line coating process on the uniaxially stretched base film obtained in the second step. As a step, the coating method may be selected from bar type coating, gravure coating, slot die coating, comma coating, etc., and the coating method is not particularly limited.

The fourth step is to biaxially stretch the base film on which the coating layer is formed, in which the co-polyester resin (A) and the incompatible resin (B) are phase separated and the incompatible resin (B) is formed into particles to give a matte property. It is a step to

The fifth step is a step of heat-treating the biaxially stretched film to finally prepare a biaxially stretched polyester matte film.

Hereinafter, the configuration of the present invention and its effects will be described in more detail through Examples and Comparative Examples. However, these examples are for explaining the present invention in more detail, and the scope of the present invention is not limited to these examples.

[Example 1]

A copolymerized polyester resin (A) having a glass transition temperature of 65° C., polymerized with 70 mol% of dimethyl terephthalate (DMT) and 30 mol% of isophthalic acid (IPA) as an acid component and 100 mol% of ethylene glycol (EG) as a diol component; An aqueous solution coating composition having a solid content of 10% was prepared by using an amorphous cyclic olefin resin having a glass transition temperature of 190° C. as the incompatible resin (B). Of the total solid components of the coating composition, the content of the co-polyester resin (A) was 60% by weight and the content of the incompatible resin (B) was mixed at a ratio of 40% by weight.

The coating composition thus prepared was applied on a polyethylene terephthalate film stretched 3.0 times in the longitudinal direction at a temperature of 100° C. after melting extrusion at a temperature of 280° C. and solidified by cooling, and then stretched 3.5 times in the transverse direction at a temperature of 110° C. After proceeding, heat treatment was performed at 180 ° C. for 30 seconds to prepare a biaxially stretched polyester matte film. The total thickness of the prepared matte film was 38 μm, and the coating thickness was 0.6 μm. In addition, the glass transition temperature of the biaxially stretched base film is 80°C and the crystallization temperature is 130°C (hereinafter the same).

[Example 2]

Copolymerized polyester with a glass transition temperature of 71°C polymerized with 100 mol% of dimethyl terephthalate as an acid component and 65 mol% of ethylene glycol and 35 mol% of 1,4-cyclohexanedimethanol (1,4-CHDM) as a diol component. Example 1 except that the resin (A) was applied and the content of the co-polyester resin (A) was 70% by weight and the content of the incompatible resin (B) was 30% by weight of the total solid components of the coating composition. Similarly, a biaxially stretched polyester matte film was prepared. The total thickness of the prepared matte film was 50 μm, and the coating thickness was 0.9 μm.

[Example 3]

Biaxially stretched polyester matte film in the same manner as in Example 2, except that the content of the co-polyester resin (A) was 85% by weight and the content of the incompatible resin (B) was 15% by weight of the total solid components of the coating composition. was manufactured. The total thickness of the prepared matte film was 50 μm, and the coating thickness was 0.9 μm.

[Example 4]

A biaxially stretched polyester matte film was prepared in the same manner as in Example 1, except that a polyacrylate resin having a glass transition temperature of 165° C. was used as the incompatible resin (B). The total thickness of the prepared matte film was 50 μm, and the coating thickness was 0.3 μm.

[Comparative Example 1]

Biaxially stretched polyester matte film in the same manner as in Example 1, except that the content of the co-polyester resin (A) was 95% by weight and the content of the incompatible resin (B) was 5% by weight of the total solid components of the coating composition. was manufactured. The total thickness of the prepared matte film was 38 μm, and the coating thickness was 0.6 μm.

[Comparative Example 2]

Of the total solid components of the coating composition, the biaxially stretched polyester matte film is the same as in Example 1, except that the content of the co-polyester resin (A) is 45% by weight and the content of the incompatible resin (B) is 55% by weight. was manufactured. The total thickness of the prepared matte film was 38 μm, and the coating thickness was 0.6 μm.

[Comparative Example 3]

Biaxially stretched polyester matte film in the same manner as in Example 2, except that the content of the co-polyester resin (A) was 25% by weight and the content of the incompatible resin (B) was 75% by weight of the total solid components of the coating composition. was manufactured. The total thickness of the prepared matte film was 50 μm, and the coating thickness was 0.9 μm.

[Comparative Example 4]

A biaxially stretched polyester matte film was prepared in the same manner as in Example 1, except that an amorphous cyclic olefin resin having a glass transition temperature of 110° C. was used as the incompatible resin (B). The total thickness of the prepared matte film was 38 μm, and the coating thickness was 0.6 μm.

[Comparative Example 5]

A biaxially stretched polyester matte film was prepared in the same manner as in Example 1, except for using an amorphous cyclic olefin resin having a glass transition temperature of 240° C. of the incompatible resin (B). The total thickness of the prepared matte film was 38 μm, and the coating thickness was 0.6 μm.

[Comparative Example 6]

A biaxially stretched polyester matte film was prepared in the same manner as in Example 1, except that the coating thickness of the matte layer was 0.003 μm. The total thickness of the produced matte film was 38 μm.

[Comparative Example 7]

A biaxially stretched polyester matte film was prepared in the same manner as in Example 1, except that the coating thickness of the matte layer was 1.20 μm. The total thickness of the produced matte film was 38 μm.

Table 1 shows the raw material composition and content of co-polyester, incompatible resin, and base film used in the manufacture of the biaxially stretched polyester matte films according to Examples 1 to 4 and Comparative Examples 1 to 7, and the conditions of the film forming process. In addition, the physical properties were measured through the following experimental example using a biaxially stretched polyester matte film, and the results are shown in Table 2 below.

[Experimental Example]

1. Gloss measurement

The 60-degree glossiness of the films prepared according to Examples and Comparative Examples was measured by the ASTM D523 method.

2. Judging glossiness and uniformity

After measuring the glossiness of the film prepared according to Examples and Comparative Examples at 100mm intervals at 10 points in the width direction, the glossiness change amount (Max. value - Min. value) was calculated to determine the gloss uniformity based on the following criteria. did

○: The amount of change in glossiness is 5 or less

△: glossiness change amount greater than 5 and less than 10

X: the amount of change in glossiness is 10 or more

3. haze measurement

The haze of the films prepared according to Examples and Comparative Examples was measured by the ASTM D1003 method.

4. Total light transmittance measurement

The total light transmittance of the films prepared according to Examples and Comparative Examples was measured by the ASTM D1003 method.

5. Film forming stability evaluation

When the film prepared according to Examples and Comparative Examples was formed for one day, film formation stability was evaluated by the number of breakages of the film, and is shown in Table 2 based on the following criteria.

○: The frequency of occurrence of film breakage is less than 1 time/day

△: The frequency of film breakage is 1 time/day to 3 times/day

X: frequency of film breakage exceeding 3 times/day

The compounds shown in Table 1 are as follows.

DMT: dimethyl terephthalate

EG: ethylene glycol

IPA: isophthalic acid

1,4-CHDM: 1,4-cyclohexanedimethanol

As confirmed in Table 2, it can be seen that the biaxially stretched polyester matte films prepared in Examples 1 to 4 of the present invention have low gloss, excellent transparency, and excellent film forming stability.

On the other hand, in Comparative Example 1, the content of the incompatible resin (B) among the total solid components of the coating composition does not satisfy the condition of 10 to 49% by weight, and when the content of the incompatible resin (B) is less than 10% by weight, phase separation It can be seen that the content of the incompatible resin to form the domain is too small, and the surface roughness is lowered, resulting in a high gloss value of 65%.

In Comparative Examples 2 and 3, the content of the co-polyester resin (A) among the total solid components of the coating composition does not satisfy the condition of 51 to 90% by weight, and the content of the co-polyester resin (A) is 50% by weight If it is less than, the co-polyester resin (A), which should form a matrix by phase separation, forms a domain, and a phase separation reversal phenomenon occurs in which the incompatible resin (B) forms a matrix only when a domain is formed, resulting in desired gloss properties can not be implemented, and it can be seen that gloss deviation and film formation stability are poor.

In Comparative Example 4, the glass transition temperature (Tg B ) of the incompatible resin ( _B ) in the coating composition is 110 ° C, which is lower than the crystallization temperature of the base film + 30 ° C (Tc _S + 30 ° C) of 160 ° C. In the heat treatment process after stretching, the incompatible resin (B) forming the domain is thermally deformed, resulting in a significantly high gloss value and a gloss deviation value, and poor film forming stability.

In Comparative Example 5, the glass transition temperature (Tg B ) of the incompatible resin ( _B ) in the coating composition was 240 ° C, and the crystallization temperature of the base film + 100 ° C (Tc _S + 100 ° C) was higher than 230 ° C. There is a problem that a large deviation occurs and film forming stability is deteriorated.

In Comparative Example 6 or 7, t _P representing the ratio of the thickness of the base film (t _S ) and the thickness of the coating layer (t _P ) / t _S is out of the range of 0.0001 to 0.01, Comparative Example 6 has a high gloss value because the coating thickness is too thin, or it can be seen that the gloss uniformity and film forming stability are poor, and Comparative Example 7 has a coating thickness Because it is too thick, it can be seen that the gloss value has a low value of 17%, but the uniformity of gloss and film forming stability are remarkably low.

As described above, the biaxially stretched polyester matte film according to an embodiment of the present invention constitutes a matte coating layer composed of a co-polyester resin (A) and an incompatible resin (B), and adjusts the thickness ratio of the base film and the coating layer, By adjusting the glass transition temperature and content of the co-polyester resin (A) and the incompatible resin (B), it is possible to provide a biaxially stretched polyester matte film with excellent transparency and matte properties and excellent film forming stability, so packaging materials or decorations It can be confirmed that the material is suitable for use in increasing marketability. However, the use of the biaxially oriented polyester matte film according to the present invention is not limited to the above use and can be used for various purposes, of course.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concept of the present invention defined in the following claims are also made according to the present invention. falls within the scope of the rights of

1: Biaxially oriented polyester base film
2: co-polyester resin (A)
3: incompatible resin (B)

Claims (14)

A biaxially stretched polyester base film and a coating layer applied with a coating composition on at least one surface of the polyester base film,
The coating layer includes a co-polyester resin (A) and an incompatible resin (B),
Equation 2 and Equation 3 are simultaneously satisfied,
(Equation 2)
TgS-50℃ ≤ TgA ≤ TgS
(Equation 3)
TcS+30℃ ≤ TgB ≤ TcS+100℃
In Equations 2 and 3, TgA is the glass transition temperature of the co-polyester resin (A), TgB is the glass transition temperature of the incompatible resin (B), TgS is the glass transition temperature of the base film, and TcS is the crystallization temperature of the base film. , Biaxially stretched polyester matte film. According to claim 1,
The biaxially stretched polyester matte film satisfies the following formula 1,
(Equation 1)
0.0001 ≤ tP / tS ≤ 0.01
Here, tS is the thickness of the base film, tP is the thickness of the coating layer, biaxially oriented polyester matte film. According to claim 1,
The coating composition is a biaxially stretched polyester matte film comprising 51 to 90% by weight of a co-polyester resin (A) and 10 to 49% by weight of an incompatible resin (B) of the total solid content. According to claim 1,
The copolymerized polyester resin (A) includes at least one of dimethyl terephthalate, terephthalic acid, isophthalic acid, and 1,4-cyclohexanedicarboxylic acid as an aromatic dicarboxylic acid component and ethylene glycol, trimethylene glycol, tetra A resin copolymerized with at least one of methylene glycol, 2,2-dimethyl (1,3-propane) diol and 1,4-cyclohexanedimethanol, a biaxially stretched polyester matte film. According to claim 1,
The incompatible resin (B) is at least one selected from crystalline polyolefin resin, amorphous cyclic olefin resin, polystyrene resin, polyacrylate resin, polycarbonate resin, polyacrylonitrile resin, polyethylene sulfide resin, and fluorine-based resin, or A homopolymer or copolymer thereof, a biaxially oriented polyester matte film. According to claim 1,
The total thickness of the biaxially oriented polyester matte film is 12 to 250㎛, the biaxially oriented polyester matte film. According to claim 1,
The biaxially oriented polyester matte film has a surface gloss of less than 50%, the biaxially oriented polyester matte film. According to claim 1,
The biaxially oriented polyester matte film has a haze of less than 10%, the biaxially oriented polyester matte film. According to claim 1,
The biaxially oriented polyester matte film has a total light transmittance of 85% or more, the biaxially oriented polyester matte film. According to claim 1,
In the process of phase separation and transverse stretching of the co-polyester resin (A) and the incompatible resin (B), the incompatible resin (B) is granulated to have a matte property, biaxially stretched polyester matte film. The biaxially oriented polyester matte film according to any one of claims 1 to 10, which is used for laminating or transferring to a packaging film or decorative film to impart matte properties to the surface of the biaxially oriented poly film. Ester matte film. A first step of manufacturing a non-stretched sheet by melting and extruding polyester chips, followed by cooling and solidifying;
A second step of stretching the non-stretched sheet in a machine direction to prepare a uniaxially stretched base film;
A third step of forming a coating layer on the uniaxially stretched base film using a coating composition in which a co-polyester resin (A) and an incompatible resin (B) are mixed;
A fourth step of biaxially stretching the base film on which the coating layer is formed in a transverse direction;
A fifth step of heat-treating the biaxially stretched film to prepare a biaxially stretched polyester matte film,
The co-polyester resin (A), the incompatible resin (B), and the base film simultaneously satisfy Equations 2 and 3 below,
(Equation 2)
TgS-50℃ ≤ TgA ≤ TgS
(Equation 3)
TcS+30℃ ≤ TgB ≤ TcS+100℃
In Equations 2 and 3, TgA is the glass transition temperature of the co-polyester resin (A), TgB is the glass transition temperature of the incompatible resin (B), TgS is the glass transition temperature of the base film, and TcS is the crystallization temperature of the base film. , Method for producing a biaxially stretched polyester matte film. According to claim 12,
The fourth step is the phase separation of the co-polyester resin (A) and the incompatible resin (B) and the incompatible resin (B) is granulated to give a matte property, manufacturing a biaxially stretched polyester matte film method. According to claim 12,
The coating composition is a method for producing a biaxially stretched polyester matte film comprising 51 to 90% by weight of a co-polyester resin (A) and 10 to 49% by weight of an incompatible resin (B) of the total solid content.

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