KR102446899B1 - Polymer film, cover window and display device comprising same - Google Patents

Abstract

The embodiment relates to a polymer film excellent in anti-blocking properties by securing an optical slip index (OS) in a specific range while maintaining a clean appearance and transparency, a manufacturing method thereof, and a front plate and a display device including the same, the polymer film contains a polymer resin and a filler selected from the group consisting of polyamide-based resins and polyimide-based resins, and has an optical slip index (OS) of less than 0.5.

Description

Polymer film, front panel and display device including same {POLYMER FILM, COVER WINDOW AND DISPLAY DEVICE COMPRISING SAME}

The embodiment relates to a polymer film excellent in anti-blocking properties by securing an optical slip index in a specific range while maintaining a clean appearance and transparency, a manufacturing method thereof, and a front plate and a display device including the same.

Polyimide-based resins are excellent in friction, heat, and chemical resistance, and are applied to primary electrical insulation materials, coating agents, adhesives, extrusion resins, heat-resistant paints, heat-resistant plates, heat-resistant adhesives, heat-resistant fibers, and heat-resistant films.

Polyimide is used in various fields. For example, polyimide is made in powder form and used as a coating agent for metal or magnet wire, etc., and is mixed with other additives depending on the purpose. In addition, polyimide is used together with fluoropolymers as decorative and anti-corrosion paints, and serves to bond fluoropolymers to metal substrates. In addition, polyimide is also used for coating kitchen cookware, and has heat and chemical resistance, so it is used as a membrane used for gas separation. used

In recent years, by filming polyimide, a polyimide-based film having excellent optical, mechanical and thermal properties while being cheaper has been developed. This polyimide-based film is applicable to display materials such as organic light-emitting diode (OLED) or liquid -crystal display (LCD), and when realizing phase difference properties, anti-reflection film, compensation film, or phase difference Applicable to film.

Such a polymer film must be smoothly wound without causing defects such as scratches by smoothly running the interface with a high-hardness guide roll passed through during the production process.

In the existing polymer film, particles such as silica have been added to implement anti-blocking properties, but as the particles agglomerate or precipitate on the film surface, the haze rises or the appearance of the film is poor.

Accordingly, research on the development of a film having a clean appearance and excellent anti-blocking properties without deterioration of optical and mechanical properties is continuously required.

An embodiment is to provide a polymer film excellent in anti-blocking properties by securing an optical slip index in a specific range while maintaining a clean appearance and transparency, a manufacturing method thereof, and a front panel and a display device including the same.

The polymer film for a display according to an embodiment includes a polymer resin and a filler selected from the group consisting of a polyamide-based resin and a polyimide-based resin, and an optical slip index (OS) expressed by the following formula 1 is less than 0.5 .

Ⅹ CKF<Equation 1> OS =

Ⅹ CKF

In Equation 1, the Hz is the haze (%) of the polymer film, and the CKF is the kinetic friction coefficient of the polymer film.

The front panel for a display according to another embodiment includes a polymer film and a functional layer, wherein the polymer film includes a polymer resin and a filler selected from the group consisting of a polyamide-based resin and a polyimide-based resin, The displayed optical slip index (OS) is less than 0.5.

A display device according to another embodiment includes a display unit; and a front plate disposed on the display unit, wherein the front plate includes a polymer film, and the polymer film includes a polymer resin and a filler selected from the group consisting of a polyamide-based resin and a polyimide-based resin, The optical slip index (OS) represented by Equation 1 is less than 0.5.

The polymer film according to one embodiment comprises the steps of: preparing a solution containing a polymer resin selected from the group consisting of a polyamide-based resin and a polyimide-based resin in an organic solvent; adding a filler dispersion in which the filler is dispersed into the solution; injecting the solution into which the filler dispersion is added into a tank; manufacturing a gel sheet by extruding and casting the solution in the tank and then drying; and heat-treating the gel sheet.

The polymer film according to the embodiment has an optical slip index in a specific range by including a filler in addition to a polymer resin selected from the group consisting of a polyamide-based resin and a polyimide-based resin, and has excellent anti-blocking properties, so it is excellent in post-processing Runability and windability can be secured.

In addition, the polymer film according to the embodiment can be usefully applied to a front panel and a display device because it has excellent optical and mechanical properties while maintaining a clean appearance.

1 is a cross-sectional view of a display device according to an exemplary embodiment.
2 is a schematic flowchart of a method for manufacturing a polymer film according to an embodiment.
3 schematically shows a process facility for a polymer film according to an embodiment.

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

Where each film, window, panel, or layer, etc. is described herein as being formed "on" or "under" each film, window, panel, or layer, etc., "on" "(on)" and "under" include both "directly" or "indirectly through" another element. In addition, the reference for the upper / lower of each component will be described with reference to the drawings. The size of each component in the drawings may be exaggerated for explanation, and does not mean the size actually applied. Also, like reference numerals refer to like elements throughout.

In the present specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

In the present specification, unless otherwise specified, the expression "a" or "a" is interpreted as meaning including the singular or the plural as interpreted in context.

In addition, it should be understood that all numbers and expressions indicating amounts of components, reaction conditions, etc. described herein are modified by the term "about" in all cases unless otherwise specified.

In this specification, terms such as first, second, etc. are used to describe various components, and the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

In addition, in the present specification, "substituted" means deuterium, -F, -Cl, -Br, -I, hydroxyl group, cyano group, nitro group, amino group, amidino group, hydrazine group, A hydrazone group, an ester group, a ketone group, a carboxyl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted alicyclic oil means substituted with one or more substituents selected from the group consisting of a group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group, wherein the above-listed substituents are linked to each other rings can be formed.

polymer film

The embodiment provides a polymer film having excellent anti-blocking properties while maintaining a clean appearance and transparency.

A polymer film according to an embodiment includes a polymer resin and a filler.

The optical slip index (OS) of the polymer film is less than 0.5.

In this case, the optical slip index OS may be expressed by Equation 1 below.

Ⅹ CKF<Equation 1> OS =

Ⅹ CKF

In Equation 1, the Hz is the haze (%) of the polymer film, and the CKF is the kinetic friction coefficient of the polymer film.

Specifically, the optical slip index of the polymer film may be 0.01 to less than 0.5, 0.01 to 0.45, 0.01 to 0.40, 0.01 to 0.35, 0.01 to 0.30, or 0.01 to 0.25, but is not limited thereto.

Since the polymer film according to the embodiment has a low optical slip index, it may have improved slip properties without increasing haze. Therefore, the polymer film according to the embodiment may exhibit clear optical properties while preventing scratches and the like caused by friction. Accordingly, the polymer film according to the embodiment is suitable for display applications.

The maximum coefficient of static friction of the polymer film is 0.380 to 0.520.

Specifically, the maximum coefficient of static friction of the polymer film may be 0.400 to 0.520, 0.420 to 0.520, 0.450 to 0.520, or 0.480 to 0.520, but is not limited thereto.

The coefficient of kinetic friction of the polymer film is 0.350 to 0.500.

Specifically, the coefficient of kinetic friction of the polymer film may be 0.365 to 0.500, 0.380 to 0.500, 0.385 to 0.500, 0.400 to 0.500, 0.430 to 0.500, or 0.460 to 0.495, but is not limited thereto.

Here, the maximum static friction coefficient and the kinetic friction coefficient mean an average value of the respective friction coefficients of the upper and lower surfaces of the polymer film.

That is, after the maximum static friction coefficient of both surfaces of the polymer film is measured, the average value of the maximum static friction coefficients of the upper and lower surfaces is the maximum static friction coefficient of the polymer film.

In addition, after the kinetic friction coefficients of both surfaces of the polymer film are measured, the average value of the kinetic friction coefficients of the upper and lower surfaces is the kinetic friction coefficient of the polymer film.

When the maximum static friction coefficient and the kinetic friction coefficient of the polymer film are within the above ranges, the winding property when wound in a roll shape and runability in the production process are excellent. Defects such as scratches or wrinkles do not occur because of excellent anti-blocking properties during such running and winding.

Specifically, when the friction coefficient range is less than the above range, the blocking property of the film surface is too low and the slip property is relatively high, so that the film deviates from the traveling path while traveling along the guide roll, or in a roll shape. When winding, there are problems such as not being able to wind properly. In addition, when the friction coefficient range exceeds the above range, the blocking property is too high and the slip property is relatively low, and the film cannot run properly due to friction with the guide roll, and the film cannot be wound in a roll shape. There is a problem such as when the roll is wound in a crumpled shape.

The haze of the polymer film is 1% or less.

Specifically, the haze of the polymer film may be 0.8% or less, 0.6% or less, or 0.5% or less, but is not limited thereto.

When the haze of the polymer film exceeds the above range, transparency is lowered, and thus it is not suitable for application to a front panel or a display device. In addition, since the screen looks hazy and dark, there is a problem in that more power is consumed to maintain a brighter screen state to compensate for this.

The refractive index (n ₁ ) of the polymer film according to an embodiment is 1.55 to 1.75. Specifically, the refractive index (n ₁ ) of the polymer film may be 1.55 to 1.70, 1.58 to 1.68, 1.60 to 1.68, 1.62 to 1.66, or 1.62 to 1.65, but is not limited thereto.

In addition, the polymer film includes a filler in addition to the polymer resin, and the refractive index (n ₂ ) of the filler is 1.55 to 1.75. Specifically, the refractive index (n ₂ ) of the filler may be 1.60 to 1.75, 1.60 to 1.70, 1.60 to 1.68, or 1.62 to 1.65, but is not limited thereto.

In a polymer film according to another embodiment, n ₁₂ according to Formula 2 is 0.2 to 3:

×100<Equation 2> n ₁₂ =

×100

In Equation 2, n ₁ is the refractive index of the polymer film, and n ₂ is the refractive index of the filler.

Specifically, n ₁₂ may be 0.2 to 2.5, 0.2 to 2.0, 0.2 to 1.5, 0.4 to 1.5, or 0.6 to 1.3, but is not limited thereto.

When n ₁₂ of the polymer film exceeds the above range, the haze may increase and mechanical strength may decrease while aggregation of the filler occurs, and in particular, the film appearance may be deteriorated.

In the polymer film according to an embodiment, n according to Equation 3 is 0.1 or less:

<Equation 3> n = │n ₁ - n ₂ │

In Equation 3, n ₁ is the refractive index of the polymer film, and n ₂ is the refractive index of the filler.

Specifically, n may be 0.08 or less, 0.06 or less, 0.05 or less, 0.04 or less, 0.03 or less, or 0.02 or less, but is not limited thereto.

When n of the polymer film exceeds the above range, the presence of the filler on the film may be visually recognized, or a problem may occur in that the filler is deposited on the surface of the film and the haze rises.

The polymer film according to another embodiment has an NC of 5 to 150 according to Equation 4:

<Equation 4> NC = (│n ₁ - n ₂ │ + 0.01) ×

In Equation 4, n ₁ is the refractive index of the polymer film, n ₂ is the refractive index of the filler, and FC means the content (ppm) of the filler based on the total weight of the polymer resin solid content.

Specifically, the NC may be 5 to 130, 5 to 120, 5 to 120, 5 to 100, 5 to 80, 10 to 80, 10 to 70, or 10 to 60, but is not limited thereto.

When the NC of the polymer film exceeds the above range, the filler may precipitate on the film surface due to aggregation of the filler, resulting in poor film appearance. In addition, when the NC of the polymer film is less than the above range, the maximum static friction coefficient and the kinetic friction coefficient value are increased to cause a blocking phenomenon, and defects such as scratches may occur during winding or post-processing of the film.

The average particle diameter of the filler included in the polymer film according to one embodiment is 110 nm to 180 nm.

Specifically, the average particle diameter of the filler may be 110 nm to 160 nm, 120 nm to 160 nm, or 130 nm to 150 nm, but is not limited thereto.

When the average particle diameter of the filler is within the above range, compared with other inorganic fillers, the optical properties do not deteriorate even when a relatively large amount is added, so that a film having a low maximum static friction coefficient and a kinetic friction coefficient is realized. can

The filler may be barium sulfate.

The barium sulfate may be included in the form of particles. In addition, the barium sulfate particles are in a state in which the surface is not subjected to a special coating treatment, and may be evenly dispersed throughout the film.

Since the polymer film contains barium sulfate, the anti-blocking property of the film can be improved without deterioration of optical properties, and mechanical properties are also excellent.

The content of the filler may be 500 ppm to 2,000 ppm based on the total weight of the polymer resin solid content.

When the content of the filler exceeds the above range, the haze of the film is rapidly increased, and aggregation of the fillers occurs on the surface of the film, so that a feeling of foreign body can be visually confirmed. Such a film may appear to have improved anti-blocking properties and winding properties due to a small coefficient of friction, but is not suitable for application to a post-process due to defects such as scratches and wrinkles.

On the other hand, when the content of the filler is less than the above range, the maximum static friction coefficient and the kinetic friction coefficient are rapidly increased, which may cause a problem in running in the production process, and the winding property is also reduced.

A polymer film according to an embodiment includes a polymer resin.

The polymer resin may be selected from the group consisting of polyamide-based resins and polyimide-based resins.

The polyamide-based resin is a resin including an amide repeating unit. The polyimide-based resin is a resin including an imide repeating unit. In addition, the resin including the imide repeating unit and including the amide repeating unit may be referred to as the polyamide-based resin, and may be referred to as the polyimide-based resin.

For example, the polymer resin may be a resin including a polyamide-based resin, a resin including a polyimide-based resin, or a resin including both a polyamide-based resin and a polyimide-based resin.

The polymer resin may be formed by polymerizing a diamine compound, a dianhydride compound, and optionally a dicarbonyl compound.

The polymer resin may be formed by simultaneously or sequentially reacting reactants including a diamine compound and a dianhydride compound. Specifically, the polymer resin is formed by polymerization of a diamine compound and a dianhydride compound.

Alternatively, the polymer resin may be formed by polymerizing a diamine compound, a dianhydride compound, and a dicarbonyl compound. In this case, the polymer resin may include an imide repeating unit derived from polymerization of a diamine compound and a dianhydride compound and an amide repeating unit derived from polymerization of the diamine compound and a dicarbonyl compound.

The polymer film according to an embodiment includes a polymer resin, wherein the polymer resin is formed by polymerizing a diamine compound, a dianhydride compound, and a dicarbonyl compound, and the molar ratio of the dianhydride compound and the dicarbonyl compound is 2:98 to 15:85.

In another embodiment, the molar ratio of the dianhydride compound and the dicarbonyl compound may be 3:97 to 15:85, 5:95 to 15:85, or 7:93 to 15:85, but is limited thereto not.

When the molar ratio of the dianhydride compound and the dicarbonyl compound is within the above range, a film having excellent optical properties, mechanical properties and anti-blocking properties may be implemented. For example, when the molar ratio of the dicarbonyl compound is relatively increased, mechanical strength such as modulus may decrease.

The diamine compound is a compound that forms a copolymer by imide bonding with the dianhydride compound and amide bonding with the dicarbonyl compound.

The diamine compound is not particularly limited, but may be, for example, an aromatic diamine compound having an aromatic structure. For example, the diamine compound may be a compound of Formula 1 below.

<Formula 1>

In Formula 1,

E is a substituted or unsubstituted divalent C ₆ -C ₃₀ aliphatic ring group, a substituted or unsubstituted divalent C ₄ -C ₃₀ heteroaliphatic ring group, a substituted or unsubstituted divalent C ₆ -C ₃₀ aromatic ring group , substituted or unsubstituted divalent C ₄ -C ₃₀ heteroaromatic ring group, substituted or unsubstituted C ₁ -C ₃₀ alkylene group, substituted or unsubstituted C ₂ -C ₃₀ alkenylene group, substituted or unsubstituted C ₂ -C ₃₀ alkynylene group, -S-, -C(=O)-, -CH(OH)-, -S(=O) ₂ -, -Si(CH ₃ ) ₂ -, -C(CH ₃ ) ₂ - and -C(CF ₃ ) ₂ - may be selected.

e is selected from an integer of 1 to 5, and when e is 2 or more, E may be the same as or different from each other.

(E) _e of Formula 1 may be selected from the group represented by Formulas 1-1a to 1-14a, but is not limited thereto.

Specifically, (E) _e of Formula 1 may be selected from the group represented by Formulas 1-1b to 1-13b, but is not limited thereto:

More specifically, (E) _e of Formula 1 may be a group represented by Formula 1-6b or a group represented by Formula 1-9b.

In one embodiment, the diamine compound may include a compound having a fluorine-containing substituent or a compound having an ether group (-O-). In this case, the fluorine-containing substituent may be a fluorinated hydrocarbon group, specifically, a trifluoromethyl group, but is not limited thereto.

In another embodiment, as the diamine compound, one type of diamine compound may be used. That is, the diamine compound may consist of a single component.

For example, the diamine compound is 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (2,2'-Bis(trifluoromethyl)-4,4 having the following structure '-diaminobiphenyl, TFDB), but is not limited thereto.

Since the dianhydride compound has a low birefringence value, it is a compound that can contribute to improvement of optical properties such as transmittance of a film including the polyimide-based resin.

The dianhydride compound is not particularly limited, but may be, for example, an aromatic dianhydride compound having an aromatic structure.

For example, the aromatic dianhydride compound may be a compound of Formula 2 below.

<Formula 2>

In Formula 2, G is a substituted or unsubstituted tetravalent C ₆ -C ₃₀ aliphatic ring group, a substituted or unsubstituted tetravalent C ₄ -C ₃₀ heteroaliphatic ring group, or a substituted or unsubstituted tetravalent C ₆ -C ₃₀ aromatic ring group, a substituted or unsubstituted tetravalent C ₄ -C ₃₀ heteroaromatic ring group, and the aliphatic ring group, the heteroaliphatic ring group, the aromatic ring group or the heteroaromatic ring group exists alone, or , are bonded to each other to form a condensed ring, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₂ -C ₃₀ alkenylene group, a substituted or unsubstituted C ₂ -C ₃₀ alkynylene group , -O-, -S-, -C(=O)-, -CH(OH)-, -S(=O) ₂ -, -Si(CH ₃ ) ₂ -, -C(CH ₃ ) ₂ - and -C(CF ₃ ) ₂ -.

G in Formula 2 may be selected from the group represented by Formulas 2-1a to 2-9a, but is not limited thereto.

For example, G in Formula 2 may be a group represented by 2-2a, a group represented by Formula 2-8a, or a group represented by 2-9a.

In one embodiment, the dianhydride compound may include a compound having a fluorine-containing substituent. In this case, the fluorine-containing substituent may be a fluorinated hydrocarbon group, specifically, a trifluoromethyl group, but is not limited thereto.

In another embodiment, the dianhydride compound may consist of one single component or two mixed components.

For example, the dianhydride compound is 2,2'-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (2,2'-Bis- (3,4 -Dicarboxyphenyl)hexafluoropropane dianhydride, 6FDA), but is not limited thereto.

The diamine compound and the dianhydride compound may be polymerized to produce a polyamic acid.

Subsequently, the polyamic acid may be converted into polyimide through a dehydration reaction, and the polyimide includes an imide repeating unit.

The polyimide may form a repeating unit represented by the following Chemical Formula A.

<Formula A>

In Formula A, descriptions of E, G and e are the same as described above.

For example, the polyimide may include a repeating unit represented by the following Chemical Formula A-1, but is not limited thereto.

<Formula A-1>

In Formula A-1, n is an integer of 1 to 400.

The dicarbonyl compound is not particularly limited, but may be, for example, a compound of Formula 3 below.

<Formula 3>

In Formula 3,

J is a substituted or unsubstituted divalent C ₆ -C ₃₀ aliphatic ring group, a substituted or unsubstituted divalent C ₄ -C ₃₀ heteroaliphatic ring group, a substituted or unsubstituted divalent C ₆ -C ₃₀ aromatic ring group , substituted or unsubstituted divalent C ₄ -C ₃₀ heteroaromatic ring group, substituted or unsubstituted C ₁ -C ₃₀ alkylene group, substituted or unsubstituted C ₂ -C ₃₀ alkenylene group, substituted or unsubstituted C ₂ -C ₃₀ alkynylene group, -O-, -S-, -C(=O)-, -CH(OH)-, -S(=O) ₂ -, -Si(CH ₃ ) ₂ -, -C(CH ₃ ) ₂ - and -C(CF ₃ ) ₂ -.

j is selected from an integer of 1 to 5, and when j is 2 or more, J may be the same as or different from each other.

X is a halogen atom. Specifically, X may be F, Cl, Br, I, or the like. More specifically, X may be Cl, but is not limited thereto.

(J) _j of Formula 3 may be selected from the group represented by Formulas 3-1a to 3-14a, but is not limited thereto.

Specifically, (J) _j of Formula 3 may be selected from the group represented by Formulas 3-1b to 3-8b, but is not limited thereto:

More specifically, (J) _j in Formula 3 may be a group represented by Formula 3-1b, a group represented by Formula 3-2b, a group represented by 3-3b, or a group represented by 3-8b. have.

In another embodiment, the dicarbonyl compound may be an aromatic dicarbonyl compound including an aromatic structure.

The dicarbonyl compound is terephthaloyl chloride (TPC), 1,1'-biphenyl-4,4'-dicarbonyl dichloride (1,1'-biphenyl-4) having the following structure ,4'-dicarbonyl dichloride, BPDC), isophthaloyl chloride (Isophthaloyl chloride, IPC), or a combination thereof may be included, but is not limited thereto.

The diamine compound and the dicarbonyl compound may be polymerized to form a repeating unit represented by the following Chemical Formula B.

<Formula B>

In Formula B, descriptions of E, J, e and j are the same as described above.

For example, the diamine compound and the dicarbonyl compound may be polymerized to form an amide repeating unit represented by Chemical Formulas B-1 and B-2.

Alternatively, the diamine compound and the dicarbonyl compound may be polymerized to form an amide repeating unit represented by Chemical Formulas B-2 and B-3.

<Formula B-1>

In Formula B-1, x is an integer of 1 to 400.

<Formula B-2>

In Formula B-2, y is an integer of 1 to 400.

<Formula B-3>

In Formula B-3, y is an integer of 1 to 400.

According to one embodiment, the polymer resin may include an imide-based repeating unit and an amide-based repeating unit in a molar ratio of 2:98 to 15:85. Specifically, the polymer resin may include an imide-based repeating unit and an amide-based repeating unit in a molar ratio of 3:97 to 15:85, 5:95 to 15:85, or 7:93 to 15:85, but It is not limited.

When the molar ratio of the imide-based repeating unit and the amide-based repeating unit is within the above range, a film having excellent anti-blocking properties and excellent optical and mechanical properties may be realized. On the other hand, when the molar ratio of the amide-based repeating unit exceeds the above range, mechanical properties such as modulus may be deteriorated.

According to one embodiment, the polymer resin may include a repeating unit represented by the following formula (A) and a repeating unit represented by the following formula (B):

<Formula A>

<Formula B>

In Formulas A and B,

E and J are each independently, a substituted or unsubstituted divalent C ₆ -C ₃₀ aliphatic ring group, a substituted or unsubstituted divalent C ₄ -C ₃₀ heteroaliphatic ring group, a substituted or unsubstituted divalent C ₆ -C ₃₀ aromatic ring group, substituted or unsubstituted divalent C ₄ -C ₃₀ heteroaromatic ring group, substituted or unsubstituted C ₁ -C ₃₀ alkylene group, substituted or unsubstituted C ₂ -C ₃₀ alkenylene group , substituted or unsubstituted C ₂ -C ₃₀ alkynylene group, -O-, -S-, -C(=O)-, -CH(OH)-, -S(=O) ₂ -, -Si( CH ₃ ) ₂ -, -C(CH ₃ ) ₂ - and -C(CF ₃ ) ₂ -;

e and j are each independently selected from an integer of 1 to 5,

when e is 2 or more, 2 or more E are the same or different from each other,

when j is 2 or more, 2 or more J are the same or different from each other,

G is a substituted or unsubstituted tetravalent C ₆ -C ₃₀ aliphatic ring group, a substituted or unsubstituted tetravalent C ₄ -C ₃₀ heteroaliphatic ring group, or a substituted or unsubstituted tetravalent C ₆ -C ₃₀ aromatic ring group , a substituted or unsubstituted tetravalent C ₄ -C ₃₀ heteroaromatic ring group, the aliphatic ring group, the heteroaliphatic ring group, the aromatic ring group or the heteroaromatic ring group is present alone, or is fused to each other to a condensed ring to form, a substituted or unsubstituted C ₁ -C ₃₀ alkylene group, a substituted or unsubstituted C ₂ -C ₃₀ alkenylene group, a substituted or unsubstituted C ₂ -C ₃₀ alkynylene group, -O-, - S-, -C(=O)-, -CH(OH)-, -S(=O) ₂ -, -Si(CH ₃ ) ₂ -, -C(CH ₃ ) ₂ - and -C(CF ₃ ) ) ₂ - are connected by a linking group selected from among.

In the polymer resin, the molar ratio of the repeating unit represented by Formula A to the repeating unit represented by Formula B is 2:98 to 15:85.

Specifically, the molar ratio of the repeating unit represented by Formula A and the repeating unit represented by Formula B may be 3:97 to 15:85, 5:95 to 15:85, or 7:93 to 15:85, but , but is not limited thereto.

The transmittance of the polymer film may be 80% or more. For example, the transmittance may be 85% or more, 88% or more, 89% or more, 80% to 99%, 80% to 99%, 85% to 99%, or 88% to 99%.

The polymer film has a yellow index of 5 or less. For example, the yellowness may be 4 or less, 3.5 or less, or 3 or less, but is not limited thereto.

The modulus of the polymer film is 5.0 GPa or more. Specifically, the modulus may be 5.5 GPa or more, 6.0 GPa or more, or 6.2 GPa or more, but is not limited thereto.

The compressive strength of the polymer film is 0.3 kgf/㎛ or more. Specifically, the compressive strength may be 0.4 kgf/㎛ or more, 0.45 kgf/㎛ or more, or 0.48 kgf/㎛ or more, but is not limited thereto.

When the polymer film is perforated at a speed of 10 mm/min using a 2.5 mm spherical tip in UTM compression mode, the maximum diameter (mm) of the perforation including cracks is 65 mm or less. Specifically, the maximum diameter of the perforation may be 5 to 60 mm, 10 to 60 mm, 15 to 60 mm, 20 to 60 mm, 25 to 60 mm, or 25 to 58 mm, but is not limited thereto.

The polymer film has a surface hardness of HB or more. Specifically, the surface hardness may be H or more or 2H or more, but is not limited thereto.

The polymer film has a tensile strength of 14 kgf/mm ² or more. Specifically, the tensile strength may be 16 kgf/mm ² or more, 18 kgf/mm ² or more, 20 kgf/mm ² or more, 21 kgf/mm ² or more, or 22 kgf/mm ² or more, but is not limited thereto.

The polymer film has an elongation of 13% or more. Specifically, the elongation may be 15% or more, 16% or more, 17% or more, or 17.5% or more, but is not limited thereto.

The polymer film according to an embodiment may secure excellent optical and mechanical properties such as low haze, yellowness, and high modulus as well as excellent anti-blocking properties that secure an optical slip index in a specific range. Accordingly, it is possible to implement a film excellent in anti-blocking properties without deterioration of mechanical properties while maintaining a clean appearance and transparency.

The above-described physical properties of the polymer film film are based on a thickness of 40 μm to 60 μm, or 70 μm to 90 μm. For example, the physical properties of the polymer film are based on a thickness of 50 μm or 80 μm.

Characteristics of the components and physical properties of the above-described polymer film may be combined with each other.

In addition, the above-described physical properties of the polymer film are results obtained by combining the process conditions of each step in the method for manufacturing the polymer film to be described later along with the chemical and physical properties of the components constituting the polymer film.

front panel

The front plate according to an embodiment includes a polymer film and a functional layer.

The front panel may be a front panel for a display.

The polymer film includes a polymer resin and a filler selected from the group consisting of a polyamide-based resin and a polyimide-based resin.

In addition, the polymer film has an optical slip index (OS) of less than 0.5 represented by Equation 1 above.

A detailed description of the polymer film is the same as described above.

The front plate may be usefully applied to a display device.

Since the polymer film has excellent anti-blocking properties and has a clean appearance and transparency, it can be usefully applied to a front panel for a display.

display device

A display device according to an embodiment includes a display unit; and a front plate disposed on the display unit, wherein the front plate includes a polymer film.

In addition, the polymer film includes a polymer resin and a filler selected from the group consisting of a polyamide-based resin and a polyimide-based resin.

Furthermore, the polymer film has an optical slip index (OS) of less than 0.5 represented by Equation 1 above.

A detailed description of the polymer film and the front plate is the same as described above.

1 is a cross-sectional view of a display device according to an exemplary embodiment.

Specifically, in FIG. 1 , a front panel including a display unit 400 and a polymer film 100 having a first surface 101 and a second surface 102 on the display unit 400 and a functional layer 200 ( 300 , in which an adhesive layer 500 is disposed between the display unit 400 and the front plate 300 is exemplified.

The display unit 400 may display an image, and may have a flexible characteristic.

The display unit 400 may be a display panel for displaying an image, for example, a liquid crystal display panel or an organic light emitting display panel. The organic light emitting display panel may include a front polarizing plate and an organic EL panel.

The front polarizing plate may be disposed on the front surface of the organic EL panel. Specifically, the front polarizing plate may be adhered to a surface on which an image is displayed in the organic EL panel.

The organic EL panel displays an image by self-luminescence in units of pixels. The organic EL panel may include an organic EL substrate and a driving substrate. The organic EL substrate may include a plurality of organic electroluminescent units respectively corresponding to pixels. Specifically, each may include a cathode, an electron transport layer, a light emitting layer, a hole transport layer, and an anode. The driving substrate may be drivably coupled to the organic EL substrate. That is, the driving substrate may be coupled to apply a driving signal, such as a driving current, to the organic EL substrate, thereby applying a current to each of the organic EL units to drive the organic EL substrate.

In addition, an adhesive layer 500 may be included between the display unit 400 and the front plate 300 . The adhesive layer may be an optically transparent adhesive layer, and is not particularly limited.

The front plate 300 is disposed on the display unit 400 . The front plate may be positioned at the outermost portion of the display device according to the embodiment to protect the display unit.

The front plate 300 may include a polymer film and a functional layer. The functional layer may be at least one selected from the group consisting of a hard coating, a reflectance reducing layer, an antifouling layer, and an antiglare layer. The functional layer may be coated on at least one surface of the polymer film.

Method for manufacturing polymer film

One embodiment provides a method of manufacturing a polymer film.

A method of manufacturing a polymer film according to an embodiment includes preparing a solution containing a polymer resin selected from the group consisting of a polyamide-based resin and a polyimide-based resin in an organic solvent; adding a filler dispersion in which the filler is dispersed into the solution; injecting the solution into which the filler dispersion is added into a tank; manufacturing a gel sheet by extruding and casting the solution in the tank and then drying; and heat-treating the gel sheet.

Referring to FIG. 2, in the method for preparing a polymer film according to an embodiment, a diamine compound, a dianhydride compound and optionally a dicarbonyl compound are mixed simultaneously or sequentially in an organic solvent in a polymerization facility, and the mixture reacting to prepare a polymer solution (S100); moving the polymer solution to a tank (S200); Purging using an inert gas (S300); Casting the polymer solution in the tank on a belt and drying it to prepare a gel-sheet (S400); Preparing a cured film by heat treatment while moving the gel-sheet (S500); cooling while moving the cured film (S600); and winding the cooled cured film using a winder (S700).

The polymer film is a film in which a polymer resin selected from the group consisting of a polyamide-based resin and a polyimide-based resin is a main component.

In the method for producing the polymer film, the polymer solution for producing the polymer resin is a diamine compound and a dianhydride compound, or a diamine compound, a dianhydride compound, and a dicarbonyl compound in an organic solvent in a polymerization facility. Or sequentially mixed and prepared by reacting the mixture (S100).

In one embodiment, the polymer solution may be prepared by simultaneously adding a diamine compound, a dianhydride compound, and optionally a dicarbonyl compound to an organic solvent to react. For example, the polymer solution may be prepared by simultaneously adding a diamine compound, a dianhydride compound, and a dicarbonyl compound to an organic solvent to react.

In another embodiment, the preparing of the polymer solution includes: preparing a polyamic acid solution by mixing and reacting the diamine compound and the dianhydride compound in a solvent; and dehydrating the polyamic acid solution to prepare a polyimide (PI) solution.

In another embodiment, the preparing of the polymer solution includes: preparing a polyamic acid (PAA) solution by first mixing and reacting the diamine compound and the dianhydride compound in a solvent; and forming an amide bond and an imide bond by secondary mixing and reacting the dicarbonyl compound with the polyamic acid (PAA) solution. The polyamic acid solution is a solution containing polyamic acid.

Alternatively, the preparing of the polymer solution may include: preparing a polyamic acid solution by first mixing and reacting the diamine compound and the dianhydride compound in a solvent; preparing a polyimide (PI) solution by dehydrating the polyamic acid solution; Secondary mixing and reaction of the dicarbonyl compound with the polyimide (PI) solution to further form an amide bond; may include. The polyimide solution is a solution containing a polymer having an imide repeating unit.

In another embodiment, preparing the polymer solution comprises the steps of: preparing a polyamide (PA) solution by first mixing and reacting the diamine compound and the dicarbonyl compound in a solvent; Secondary mixing and reaction of the dianhydride compound with the polyamide (PA) solution to further form an imide bond; may include. The polyamide solution is a solution containing a polymer having an amide repeating unit.

The polymer solution prepared as described above may be a solution containing a polymer including at least one selected from the group consisting of polyamic acid (PAA) repeating units, polyamide (PA) repeating units, and polyimide (PI) repeating units. .

For example, the polymer included in the polymer solution may include an imide repeating unit derived from polymerization of the diamine compound and the dianhydride compound.

Alternatively, the polymer contained in the polymer solution is an imide repeating unit derived from the polymerization of the diamine compound and the dianhydride compound and an amide derived from the polymerization of the diamine compound and the dicarbonyl compound. It may contain repeating units.

The content of the solids contained in the polymer solution may be 10% by weight to 30% by weight. Alternatively, the content of the solids contained in the polymer solution may be 15 wt% to 25 wt%, but is not limited thereto.

When the content of the solids contained in the polymer solution is within the above range, the polymer film can be effectively manufactured in the extrusion and casting process. In addition, the prepared polymer film has excellent anti-blocking properties by securing an optical slip index, a maximum static friction coefficient, and a kinetic friction coefficient in a specific range while maintaining a clean appearance and transparency.

In one embodiment, preparing the polymer solution may further include adding a catalyst.

In this case, the catalyst may include at least one selected from the group consisting of betapicoline, acetic anhydride, isoquinoline (IQ) and pyridine-based compounds, but is not limited thereto.

The catalyst may be added in 0.01 to 0.4 molar equivalent based on 1 mole of the polyamic acid, but is not limited thereto.

When the catalyst is added, the reaction rate may be improved, and chemical bonding between repeating unit structures or within the repeating unit structure may be improved.

In another embodiment, the preparing of the polymer solution may further include adjusting the viscosity of the polymer solution.

Specifically, preparing the polymer solution comprises: (a) preparing a first polymer solution by simultaneously or sequentially mixing and reacting a diamine compound, a dianhydride compound, and optionally a dicarbonyl compound in an organic solvent; (b) measuring the viscosity of the first polymer solution to evaluate whether the target viscosity is reached; and (c) when the viscosity of the first polymer solution does not reach the target viscosity, adding the dianhydride compound or dicarbonyl compound to prepare a second polymer solution having the target viscosity; can

The target viscosity may be 100,000 cps to 500,000 cps at room temperature. Specifically, the target viscosity may be 100,000 cps to 400,000 cps, 100,000 cps to 350,000 cps, 100,000 cps to 300,000 cps, 150,000 cps to 300,000 cps, or 150,000 to 250,000 cps at room temperature However, the present invention is not limited thereto.

In the case of the step of preparing the first polymer solution and the step of preparing the second polymer solution, the viscosity of the prepared polymer solution is different. For example, the viscosity of the second polymer solution is higher than that of the first polymer solution.

The stirring speed when preparing the first polymer solution is different from the stirring speed when preparing the second polymer solution. For example, the stirring speed when preparing the first polymer solution is faster than the stirring speed when preparing the second polymer solution.

In another embodiment, preparing the polymer solution may further include adjusting the pH of the polymer solution. In this step, the pH of the polymer solution may be adjusted to 4 to 7, for example, may be adjusted to 4.5 to 7, but is not limited thereto.

The pH of the polymer solution may be adjusted by adding a pH adjusting agent, and the pH adjusting agent is not particularly limited, but may include, for example, an amine-based compound such as alkoxyamine, alkylamine, or alkanolamine.

By adjusting the pH of the polymer solution to the above range, it is possible to prevent damage to equipment in the subsequent process, prevent the occurrence of defects in the film prepared from the polymer solution, and have desired optical properties in terms of yellowness and modulus and mechanical properties.

The pH adjusting agent may be added in an amount of 0.1 mol% to 10 mol% based on the total number of moles of monomers in the polymer solution.

In another embodiment, preparing the polymer solution may further include purging using an inert gas. By removing moisture and reducing impurities through the inert gas purging step, the reaction yield can be increased, and the surface appearance and mechanical properties of the final film can be excellently implemented.

The inert gas may be at least one selected from the group consisting of nitrogen, helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn), but is limited thereto not. Specifically, the inert gas may be nitrogen.

The molar ratio of the dianhydride compound and the dicarbonyl compound used to prepare the polymer solution may be 2:98 to 15:85. For example, the molar ratio may be 3:97 to 15:85, 5:95 to 15:85, or 7:93 to 15:85, but is not limited thereto.

By using the dianhydride compound and the dicarbonyl compound in such a molar ratio, it is advantageous to achieve a target level of mechanical properties and optical properties of the polyamide-imide film prepared from the polymer solution.

The description of the diamine compound, the dianhydride compound, and the dicarbonyl compound is the same as described above.

In one embodiment, the organic solvent is dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (N-methyl-2-pyrrolidone, NMP), m- It may be at least one selected from the group consisting of cresol (m-cresol), tetrahydrofuran (THF) and chloroform. The organic solvent used in the polymer solution may be dimethylacetamide (DMAc), but is not limited thereto.

After preparing a polymer solution including a polymer resin in an organic solvent as described above, a filler dispersion in which the filler is dispersed is added to the solution.

The average particle diameter of the filler is 110 nm to 180 nm. Also, the filler is barium sulfate.

The content of the filler may be 500 ppm to 2,000 ppm based on the total weight of the polymer resin solid content, but is not limited thereto.

A more detailed description of the filler is as described above.

The filler dispersion may further include a dispersant.

The dispersant serves to help the filler to be uniformly dispersed in the dispersion solution and in the polymer solution including the polymer resin.

In this case, it is preferable to use a neutral-based dispersant as the dispersant.

In the filler dispersion, the content of the filler solids contained in the filler dispersion is 10% by weight to 30% by weight.

When the content of the filler included in the filler dispersion is within the above range, the filler is evenly dispersed and may be appropriately mixed with a polymer solution including a polymer resin. In addition, aggregation between fillers is minimized, and when it is made into a film, foreign substances do not appear on the film surface, and optical and mechanical properties of the film can be improved together.

In addition, the filler dispersion may further include a solvent.

The solvent may be an organic solvent, and specifically, dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (N-methyl-2-pyrrolidone, NMP) , m-cresol (m-cresol), tetrahydrofuran (tetrahydrofuran, THF) and may be at least one selected from the group consisting of chloroform. Preferably, the solvent included in the filler dispersion may be dimethylacetamide (DMAc), but is not limited thereto.

Next, the polymer solution into which the filler dispersion is added is moved to the tank (S200).

Figure 3 schematically shows the manufacturing process equipment of the polymer film according to an embodiment. Referring to FIG. 3 , the polymer solution described above is prepared in a polymerization facility 10 , and the polymer solution thus prepared is moved and stored in a tank 20 .

At this time, after preparing the polymer solution, the step of moving the polymer solution to the tank is performed without a separate process. Specifically, the polymer solution prepared in the polymerization facility is moved to the tank as it is and stored without a separate precipitation and re-dissolution process to remove impurities. Conventionally, in order to remove impurities such as hydrochloric acid (HCl) generated during the preparation of the polymer solution, the prepared polymer solution is purified through a separate process to remove impurities, and a process of re-dissolving it in a solvent was performed. . However, in this case, the loss of the active ingredient increases in the process of removing impurities, and as a result, there is a problem that the yield is lowered.

Accordingly, in the manufacturing method according to an embodiment, the content of impurities is fundamentally minimized in the manufacturing process of the polymer solution, or even if certain impurities are present, they are appropriately controlled in a subsequent process to prevent deterioration of the physical properties of the final film. It has the advantage of producing a film without a separate precipitation or re-dissolution process.

The tank 20 is a place for storing the polymer solution before filming, and the internal temperature thereof may be -20°C to 20°C.

Specifically, the internal temperature may be -20°C to 10°C, -20°C to 5°C, -20°C to 0°C, or 0°C to 10°C, but is not limited thereto.

By controlling the internal temperature of the tank 20 in the above range, it is possible to prevent the polymer solution from being deteriorated during storage, and it is possible to reduce the moisture content to prevent defects of the film prepared therefrom.

The method of manufacturing the polymer film may further include performing vacuum defoaming on the polymer solution moved to the tank 20 .

The vacuum defoaming may be performed for 30 minutes to 3 hours after reducing the internal pressure of the tank to 0.1 bar to 0.7 bar. By performing vacuum defoaming under these conditions, bubbles inside the polymer solution can be reduced, and as a result, surface defects of the film prepared therefrom can be prevented, and optical properties such as haze can be excellently implemented.

In addition, the method of manufacturing the polymer film may further include purging the polymer solution moved to the tank 20 using an inert gas (S300).

Specifically, the purging is performed by purging the internal pressure of the tank to 1 to 2 atmospheres using an inert gas. By performing nitrogen purging under these conditions, moisture in the polymer solution is removed and impurities are reduced, so that the reaction yield can be increased, and optical properties such as haze and mechanical properties can be excellently implemented.

The inert gas may be at least one selected from the group consisting of nitrogen, helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn), but is limited thereto not. Specifically, the inert gas may be nitrogen.

The vacuum defoaming step and the step of purging the tank using an inert gas are performed as separate processes.

For example, the vacuum defoaming step is performed, and thereafter, the step of purging the tank with an inert gas may be performed, but is not limited thereto.

By performing the vacuum defoaming step and/or the step of purging the tank using an inert gas, the physical properties of the surface of the prepared polymer film can be improved.

Thereafter, the method may further include storing the polymer solution in the tank 20 for 1 hour to 360 hours. At this time, the internal temperature of the tank may be continuously maintained at -20 °C to 20 °C.

The method for manufacturing the polymer film includes extruding and casting the polymer solution in the tank 20 and drying the gel-sheet (S400).

The polymer solution may be cast on a casting such as a casting roll or a casting belt.

Referring to FIG. 3 , according to one embodiment, the polymer solution may be applied as a casting body on the casting belt 30 and dried while moving, and may be manufactured into a sheet in the form of a gel.

When the polymer solution is injected onto the belt 30, the injection rate may be 300 g/min to 700 g/min. When the injection rate of the polymer solution satisfies the above range, the gel-sheet may be uniformly formed with an appropriate thickness.

In addition, the casting thickness of the polymer solution may be 200㎛ to 700㎛. When the polymer solution is cast to the thickness range and dried and heat treated to form a final film, appropriate thickness and thickness uniformity can be ensured.

As described above, the polymer solution may be 100,000 cps to 500,000 cps at room temperature, for example, 100,000 cps to 400,000 cps, 100,000 cps to 350,000 cps, 150,000 cps to 350,000 cps or It may be 150,000 cps to 250,000 cps. By satisfying the above viscosity range, the polymer solution can be cast to a uniform thickness without defects when cast on a belt.

After casting the polymer solution, it is dried at a temperature of 60° C. to 150° C. for a time of 5 minutes to 60 minutes to prepare a gel-sheet. Specifically, the drying may be performed for a time of 10 to 50 minutes with hot air of 60°C to 120°C.

During the drying, some or all of the solvent of the polymer solution is volatilized to prepare the gel-sheet.

The moving speed of the gel-sheet on the casting body during drying may be 0.1 m/min to 15 m/min, for example, 0.5 m/min to 10 m/min, but is not limited thereto.

The manufacturing method of the polymer film includes the step of preparing a cured film by heat treatment while moving the gel-sheet (S500).

Referring to FIG. 3 , the heat treatment of the gel-sheet may be performed by passing through a thermosetting machine 40 .

The heat treatment of the gel-sheet is performed in a range of 80° C. to 500° C. for 5 minutes to 180 minutes. Specifically, the heat treatment of the gel-sheet may be performed for 5 minutes to 150 minutes while raising the temperature at a rate of 2°C/min to 80°C/min in the range of 80°C to 500°C. More specifically, the heat treatment of the gel-sheet may be performed by increasing the temperature at a rate of 2°C/min in a temperature range of 80°C to 300°C.

According to one embodiment, the gel-sheet may be treated with hot air.

When the heat treatment by hot air is performed, the amount of heat may be uniformly provided. If the amount of heat is not evenly distributed, satisfactory mechanical properties cannot be achieved. In particular, a satisfactory surface roughness cannot be realized, and in this case, the surface tension may increase or decrease too much.

By heat treatment under these conditions, the gel-sheet may be cured to have appropriate surface hardness and modulus.

The manufacturing method of the polymer film includes the step of cooling while moving the cured film (S600).

3, the cured film is performed after passing through the thermosetting machine 40, may be performed using a separate cooling chamber (not shown), and an appropriate temperature atmosphere without a separate cooling chamber It may be carried out by composition.

The cooling while moving the cured film may include: a first temperature reduction step of reducing the temperature at a rate of 100° C./min to 1000° C./min; and a second temperature reduction step of reducing the temperature at a rate of 40° C./min to 400° C./min.

In this case, the second temperature reduction step may be performed after the first temperature reduction step, and the temperature reduction rate of the first temperature reduction step may be faster than the temperature reduction rate of the second temperature reduction step.

For example, the maximum speed during the first temperature reduction step is faster than the maximum speed during the second temperature reduction step. Alternatively, the lowest speed during the first temperature reduction step is faster than the lowest speed during the second temperature reduction step.

As the cooling step of the cured film is performed in multiple steps as described above, the physical properties of the cured film can be more stabilized, and the optical and mechanical properties of the film established in the curing process can be stably maintained for a long period of time.

The moving speed of the gel-sheet and the cured film is the same.

The method of manufacturing the polymer film includes winding the cooled cured film using a winder (S700).

Referring to FIG. 3 , the winding of the cooled cured film may be performed using a roll-type winder 50 .

At this time, the ratio of the moving speed of the gel-sheet on the belt during drying to the moving speed of the cured film during winding is 1:0.95 to 1:1.40. Specifically, the ratio of the moving speed may be 1:0.99 to 1:1.20, 1:0.99 to 1:1.10, or 1:1.10 to 1:1.05, but is not limited thereto.

When the ratio of the moving speed is out of the above range, there is a fear that mechanical properties of the cured film may be damaged, and there is a risk that flexibility and elastic properties may be deteriorated.

In the manufacturing method of the polymer film, the thickness deviation (%) according to the following general formula 1 may be 3% to 30%. Specifically, the thickness deviation (%) may be 5% to 20%, but is not limited thereto.

<General formula 1> Thickness deviation (%) = {(M1-M2)/M1} X 100

In Formula 1, M1 is the thickness (μm) of the gel-sheet, and M2 is the thickness (μm) of the cured film cooled during winding.

The polymer film may exhibit excellent anti-blocking properties, optical and mechanical properties by being manufactured according to the above-described manufacturing method. The polymer film may be applicable to various uses requiring durability and transparency. For example, the polymer film may be applied to a solar cell, a semiconductor device, a sensor, etc. in addition to a display device.

The description of the polymer film prepared according to the above-described manufacturing method is the same as described above.

The above will be described in more detail with reference to the following examples. However, the following examples are only for illustrating the present invention, and the scope of the examples is not limited thereto.

<Example>

Example One

After filling a double-jacketed, temperature-controlled, 1-L glass reactor with dimethylacetamide (DMAc), an organic solvent, under a nitrogen atmosphere at 20°C, 2,2'-bis(trifluoromethyl)-4,4'- Diaminobiphenyl (TFDB) was slowly added and dissolved. Then, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6-FDA) was slowly added and stirred for 1 hour. Then, terephthaloyl chloride (TPC) and isophthaloyl chloride (IPC) were added and stirred for 1 hour to prepare a polymer solution.

Then, a dispersion of barium sulfate (solids content of 18.2% by weight, organic solvent DMAc) was added to the polymer solution and stirred.

The obtained polymer solution was applied to a glass plate, dried with hot air at 80 ° C. for 30 minutes, peeled from the glass plate, fixed to a pin frame, and heated at a rate of 2 ° C./min in a temperature range of 80 ° C. to 300 ° C. to gel- The sheet was dried to obtain a polymer film having a thickness of 50 µm.

With respect to the contents of the diamine compound (TFDB), the dianhydride compound (6FDA), and the dicarbonyl compound (TPC, IPC), the respective input molar ratios are shown in Table 1. The number of moles of the dianhydride compound and the dicarbonyl compound is described based on 100 moles of the diamine compound.

In addition, the type, refractive index, and content of the filler are described in Table 1.

Example 2 to 6 and comparative example 1 to 4

As shown in Table 1 below, a film was prepared in the same manner as in Example 1, except that each reactant and the type and content of the filler were different.

<Evaluation example>

The following physical properties were measured and evaluated for the films prepared in Examples 1 to 6 and Comparative Examples 1 to 4, and the results are shown in Table 2 below.

evaluation example 1: Maximum static friction coefficient/kinetic friction coefficient

Using a friction coefficient tester (QM110CF) from QMESYS, the maximum static friction coefficient and kinetic friction coefficient were measured under the conditions of a vertical load of 205 g, a film size of 63.5 mm X 63.5 mm, and a measurement speed of 150 mm/min, based on ASTM D1894 measurement. .

evaluation example 2: transmittance and haze measurement

The light transmittance at 550 nm was measured using a haze meter NDH-5000W of Denshoku Kogyo, Japan.

evaluation example 3: Yellowness measurement

Yellow Index (YI) was measured using a CIE colorimeter by a spectrophotometer (UltraScan PRO, Hunter Associates Laboratory).

evaluation example 4: modulus measurement

Using Instron's universal testing machine UTM 5566A, the sample was cut to 5 cm or more in the direction orthogonal to the main shrinkage direction and 10 mm in the main shrinkage direction. A stress-strain curve was obtained until fracture occurred while stretching. In the stress-strain curve, the slope of the load with respect to the initial strain was defined as the modulus (GPa).

evaluation example 5: Evaluation of film surface condition

The surface of the prepared film was visually observed using eyes.

At this time, the case where agglomeration of particles was not seen at all on the film surface was indicated by ◎, the case where it was rarely seen was indicated by ○, and the case where the aggregation was visually observed with high frequency was indicated by X.

As can be seen in Tables 1 and 2, it was confirmed that the polymer films of Examples 1 to 6 had an optical slip index of less than 0.5, so that they could have improved optical properties and improved slip properties at the same time.

In addition, it was confirmed that the polymer films of Examples 1 to 4 had excellent anti-blocking properties because the maximum static friction coefficient and the kinetic friction coefficient were as low as 0.520 and 0.500 or less, respectively, and exhibited excellent optical properties as the haze was also lowered to 1% or less. .

In this case, the anti-blocking property indicates a characteristic of smooth sliding at the interface in contact with the film, and the better the anti-blocking property, the better the runability and winding property in the production process. That is, if the anti-blocking property is excellent, defects do not occur on the film because it is soft without much friction between the films when winding or unwinding the film.

In addition, the polymer films of Examples 1 to 4 did not exhibit aggregation or precipitation between fillers, so the film surface was clean, and properties such as transmittance and modulus in addition to the above-described friction coefficient and haze properties were also at a certain level. By showing the above, it was confirmed that there was no problem when the film was applied to a front plate or a display device.

On the other hand, in the case of the polymer films of Comparative Examples 1 to 4, compared to the films of Examples 1 to 6, the maximum static friction coefficient or the kinetic friction coefficient is relatively high, so that the anti-blocking property is lowered, or the haze is more than 1% of the optical properties This showed a falling result.

In addition, in the case of Comparative Example 4, the surface state of the film was not clean, and aggregation or precipitation of particles was visually confirmed. It was not suitable for application to the post-process, such as

10: polymerization plant 20: tank
30: belt 40: thermosetting machine
50 : winder
100: polymer film
101: first surface 102: second surface
200: functional layer 300: front panel
400: display unit 500: adhesive layer

Claims (16)

Including a polymer resin and a filler containing a polyamide-based resin,
The filler is barium sulfate,
The optical slip index (OS) represented by the following formula 1 is less than 0.5,
NC of the formula 4 is 5 to 150, a polymer film for display:
<Equation 1> OS =

Ⅹ CKF
In Equation 1, the Hz is the haze (%) of the polymer film, the CKF is the kinetic friction coefficient of the polymer film,
<Equation 4> NC = (│n ₁ - n ₂ │ + 0.01) ×

In Equation 4, n ₁ is the refractive index of the polymer film, n ₂ is the refractive index of the filler, and FC means the content (ppm) of the filler based on the total weight of the polymer resin solid content.
According to claim 1,
The optical slip index is 0.01 to 0.40, a polymer film for a display.
According to claim 1,
The maximum coefficient of static friction of the polymer film is 0.380 to 0.520,
The coefficient of kinetic friction of the polymer film is 0.350 to 0.500,
The haze of the polymer film is 1% or less, a polymer film for a display.
4. The method of claim 3,
The maximum coefficient of static friction of the polymer film is 0.400 to 0.520,
The coefficient of kinetic friction of the polymer film is 0.380 to 0.500,
A polymer film for a display having a haze of 0.5% or less of the polymer film.
According to claim 1,
In Formula 2, n ₁₂ is 0.2 to 3, a polymer film for a display:
<Equation 2> n ₁₂ =

×100
In Equation 2, n ₁ is the refractive index of the polymer film, and n ₂ is the refractive index of the filler.
According to claim 1,
In the following formula 3, n is 0.1 or less, a polymer film for a display:
<Equation 3> n = │n ₁ - n ₂ │
In Equation 3, n ₁ is the refractive index of the polymer film, and n ₂ is the refractive index of the filler.
According to claim 1,
The refractive index of the filler is 1.55 to 1.75,
The refractive index of the polymer film is 1.55 to 1.75, a polymer film for a display.
delete According to claim 1,
The average particle diameter of the filler is 110 nm to 180 nm, a display polymer film.
According to claim 1,
The content of the filler is 500 ppm to 2,000 ppm based on the total weight of the polymer resin solid content, a polymer film for a display.
According to claim 1,
The transmittance of the polymer film is 80% or more,
Yellowness of the polymer film is 3 or less,
The polymer film has a modulus of 5 GPa or more, a polymer film for a display.
Including a polymer film and a functional layer,
The polymer film includes a polymer resin including a polyamide-based resin and a filler, wherein the filler is barium sulfate,
The optical slip index (OS) represented by the following formula 1 is less than 0.5,
NC of the following formula 4 is 5 to 150, a front panel for a display:
<Equation 1> OS =

Ⅹ CKF
In Equation 1, the Hz is the haze (%) of the polymer film, the CKF is the kinetic friction coefficient of the polymer film,
<Equation 4> NC = (│n ₁ - n ₂ │ + 0.01) ×

In Equation 4, n ₁ is the refractive index of the polymer film, n ₂ is the refractive index of the filler, and FC means the content (ppm) of the filler based on the total weight of the polymer resin solid content.
display unit; and
Including; a front plate disposed on the display unit;
The front plate comprises a polymer film,
The polymer film includes a polymer resin including a polyamide-based resin and a filler, wherein the filler is barium sulfate,
The optical slip index (OS) represented by the following formula 1 is less than 0.5,
NC of the following formula 4 is 5 to 150, a display device:
<Equation 1> OS =

Ⅹ CKF
In Equation 1, the Hz is the haze (%) of the polymer film, the CKF is the kinetic friction coefficient of the polymer film,
<Equation 4> NC = (│n ₁ - n ₂ │ + 0.01) ×

In Equation 4, n ₁ is the refractive index of the polymer film, n ₂ is the refractive index of the filler, and FC means the content (ppm) of the filler based on the total weight of the polymer resin solid content.
preparing a solution containing a polymer resin including a polyamide-based resin in an organic solvent;
adding a filler dispersion in which barium sulfate is dispersed as a filler to the solution;
injecting the solution into which the filler dispersion is added into a tank;
manufacturing a gel sheet by extruding and casting the solution in the tank and then drying; and
Including; heat-treating the gel sheet;
The method for producing the polymer film of claim 1.
delete 15. The method of claim 14,
The content of the filler solids contained in the filler dispersion is 10% by weight to 30% by weight, a method for producing a polymer film.

Images