KR20210086552A - Polyimide based film - Google Patents

Abstract

The present invention provides a polyimide-based film, which comprises a copolymer of diamine compound, first dicarbonyl compound and second dicarbonyl compound components, wherein 55 to 90 moles of the first dicarbonyl compound and 10 to 45 moles of the second dicarbonyl compound are contained based on 100 moles of the diamine compound, and which has improved surface touch feeling.

Description

Polyimide-based film {POLYIMIDE BASED FILM}

The present invention relates to a polyimide-based film and a polyimide-based film body including the same.

Polyimide-based resins have characteristics such as high heat resistance, oxidation resistance, radiation resistance, low temperature characteristics, and chemical resistance, and are widely used in electronic products, semiconductors, automobiles, aircraft, spacecraft, etc., optical fibers, display devices, and transparent electrode films. It is also used as a cover window of a display device.

Recently, studies to improve the optical properties of polyimide-based resins have been conducted, and polyimide-based resins having excellent optical properties without significantly lowering mechanical and thermal properties have been developed.

A polyimide-based film made of a polyimide-based resin having excellent mechanical properties, thermal properties and optical properties is used in various flexible products, and studies are being conducted to use it as a substitute for glass. For example, studies for using a polyimide-based film as a cover window or a protective material of a display device are being conducted.

An object of the present invention is to realize an organic layer or an organic-inorganic hybrid layer capable of improving the physical properties of electronic devices including window members due to excellent optical properties, and a polyimide-based film having excellent surface touch, and a polyimide-based film including the same It aims to provide a body.

Another object of the present invention is to provide a polyimide-based film capable of implementing an organic layer or an organic-inorganic hybrid layer usable in a flexible device due to high yield elongation, and a polyimide-based film body including the same.

According to an embodiment of the present invention, it comprises a copolymer of a diamine compound, a first dicarbonyl compound, and a second dicarbonyl compound component,

With respect to 100 moles of the diamine compound,

55 to 90 moles of the first dicarbonyl compound, and 10 to 45 moles of the second dicarbonyl compound,

The surface touch feeling according to the following formula 1 is 30.6 or more.

[Equation 1]

Surface touch feeling = T x (500-G)

(In Equation 1, T is a value (unit W / mK) of the thermal conductivity of the polyimide-based film surface measured by ASTM E1461 with LFA467 (ZETZSCH) equipment, and G is the glossiness of the polyimide-based film surface value determined at an angle of 20 degrees (unit GU) by ASTM D523 measurement method)

For reference, in Equation 1, the lower the gloss, the glass-like texture, so the value obtained by subtracting the G value of the sample measured from an arbitrary absolute value of 500 is multiplied by the thermal conductivity to quantify the surface touch feeling.

In this case, the polyimide-based film may have a surface touch feeling according to Formula 1, for example, 30.6 to 41.8, 31 to 41.8, 32 to 41.8, 33 to 41.8, 34 to 41.8, or 35 to 41.8.

The polyimide-based film may include an aromatic dianhydride compound, and the aromatic dianhydride compound may be included in a ratio of 20 moles or less with respect to 100 moles of the diamine compound.

The diamine compound is oxydianiline (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMDA), bisaminophenoxy Cy Benzene (133APB), Bis Aminophenoxy Benzene (134APB), Bis Amino Phenoxy Phenyl Hexafluoropropane (4BDAF), Bis Aminophenyl Hexafluoropropane (33-6F) -6F), bisaminophenylsulfone (4DDS), bisaminophenylsulfone (3DDS), bistrifluoromethyl benzidine (TFDB), cyclohexanediamine (13CHD), cyclohexanediamine (14CHD), bisaminophenoxyphenylpropane (6HMDA), bis aminohydroxy phenyl hexafluoropropane (DBOH), bis amino phenoxy diphenyl sulfone (DBSDA), bis (4-aminophenyl) fluorene (FDA) and bis (4-amino-3) Fluorophenyl) may include at least one selected from fluorene (F-FDA).

The first dicarbonyl compound may include at least one of a first aromatic dicarbonyl compound and a first aliphatic dicarbonyl compound.

The second dicarbonyl compound may include at least one of a second aromatic dicarbonyl compound and a second aliphatic dicarbonyl compound.

The first aromatic dicarbonyl compound and the second aromatic dicarbonyl compound may be each independently selected from compounds represented by Formula 1 below.

[Formula 1]

Here, R ₁ is a single bond, arylene (*-Ar-*), oxyarylene (*-O-Ar-*), cycloalkylene (*-CAL-*), or oxycycloalkylene (*- O-CAL-*), X ₁ and X ₂ each independently represent hydrogen, a hydroxyl group (OH) or a halogen element, and X ₃ represents hydrogen or a halogen element. Here, "Ar" represents a substituted or unsubstituted arylene group, and CAL represents a cycloaliphatic group.

The first aromatic dicarbonyl compound and the second aromatic dicarbonyl compound are each independently represented by a compound represented by the following Chemical Formula 3, a compound represented by the following Chemical Formula 4, a compound represented by the following Chemical Formula 5, and represented by the following Chemical Formula 6 It may include at least one of a compound represented by the following formula (7), a compound represented by the following formula (8), and a compound represented by the following formula (9).

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

The first aliphatic dicarbonyl compound and the second aliphatic dicarbonyl compound are each independently represented by a compound represented by the following Chemical Formula 10, a compound represented by the following Chemical Formula 11, a compound represented by the following Chemical Formula 12, and a compound represented by the following Chemical Formula 13 It may contain at least one of the compounds.

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

The aromatic dianhydride is 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), biphenyl tetracarboxylic dianhydride (BPDA), 4- (2,5) -dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA), pyromellitic acid dianhydride (PMDA), benzophenone Tetracarboxylic dianhydride (BTDA), oxydiphthalic dianhydride (ODPA), biscarboxyphenyl dimethyl silane dianhydride (SiDA), bis dicarboxyphenoxy diphenyl sulfide dianhydride (BDSDA), sulfonyl Diphthalic anhydride (SO ₂ DPA), Isopropylideneiphenoxy bis phthalic anhydride (6HBDA), Cyclobutanedianhydride (CBDA), Cyclopentanedianhydride (CPDA), Cyclohexanedianhydride It may include at least one selected from (CHDA) and bicyclohexanedianhydride (HBPDA).

The polyimide-based film, based on a thickness of 50 ± 2㎛, glossiness of 239 ~ 253GU; thermal conductivity of 0.12 to 0.18 W/mK; It may have an elongation at yield in the machine direction (MD) of 1.8% or more, an elongation at yield in the width direction (TD) of 1.8% or more, an average optical transmittance of 90% or more at a wavelength of 380 to 780 nm, and a haze of 0.3% or less.

Another embodiment of the present invention is a polyimide-based film body including the above-described polyimide-based film, on one or both sides of the polyimide-based film, a primer film, a hardness-reinforced film, a flexible film, and a fold It provides a polyimide-based film body comprising at least one coating layer selected from a film, a flexural strength reinforcing film, a visibility improving film, a barrier film, an antibacterial film, a water-repellent film, an anti-fingerprint film, an anti-reflection film, and a film providing a smooth touch. .

Another embodiment of the present invention provides an electronic device including the polyimide-based film.

According to an embodiment of the present invention, an organic layer or an organic-inorganic hybrid layer capable of improving the physical properties of electronic devices including a window member due to excellent optical properties can be implemented, and a polyimide-based film having excellent surface touch feeling, and a polyimide-based film comprising the same A polyimide-based film body was provided.

According to an embodiment of the present invention, a polyimide-based film capable of implementing an organic layer or an organic-inorganic hybrid layer usable in a flexible device due to high yield elongation, and a polyimide-based film body including the same are provided.

A polyimide-based film prepared according to an embodiment of the present invention and having excellent surface touch feeling and a polyimide-based film body including the same may be used as an alternative to glass.

Before describing the present invention in detail, it is to be understood that the terminology used herein is for the purpose of describing specific embodiments only, and does not limit the scope of the present invention, which is limited only by the appended claims.

All technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art, unless otherwise stated.

Throughout this specification and claims, unless otherwise stated, the term comprise, comprises, comprising means including the referenced object or step or set of objects or groups of steps, and any It is not used in the sense of excluding other objects or steps, groups of objects or groups of steps.

On the other hand, various embodiments of the present invention may be combined with any other embodiments unless clearly indicated to the contrary. In particular, any feature indicated as preferred or advantageous may be combined with any other feature indicated as preferred or advantageous.

In this specification, the term "film" generally refers to a thin plate-like member, but also includes the concept of a film formed by liquid coating.

In the present specification, the term "film body" is intended to include a structure including or laminated with one or more layers of the above-described films, and furthermore, a device having such a structure.

In the present specification, the term "polyimide-based" is intended to collectively include polyimide, polyamide, and polyimide-based.

In addition, the concept of “locating on” in the present specification should be understood as being positioned “on” not only directly on it, but also on other members intervening therebetween.

Although the first, second, etc. are used to describe various components, these components are not limited by these terms. These terms are only used to distinguish one component from another. Accordingly, the first component mentioned below may be the second component within the spirit of the present invention.

The term “at least one” should be understood to include all possible combinations from one or more related items. For example, the meaning of "at least one of the first, second, and third items" means 2 of the first, second, and third items as well as each of the first, second, or third items. It may mean a combination of all items that can be presented from more than one.

Each feature of the various embodiments of the present invention may be partially or wholly combined or combined with each other, technically various interlocking and driving are possible, and each of the embodiments may be implemented independently of each other or may be implemented together in a related relationship. may be

The polyimide-based film according to an embodiment of the present invention includes a copolymer of a diamine compound, a first dicarbonyl compound, and a second dicarbonyl compound component, and based on 100 moles of the diamine compound, the first dicarbo The nyl compound is contained in a ratio of 55 to 90 moles, and the second dicarbonyl compound is contained in a ratio of 10 to 45 moles, and the surface touch feeling according to Formula 1 to be described below is 30.6 or more. The polyimide-based film can implement an organic layer or an organic-inorganic hybrid layer that can improve the physical properties of electronic devices including window members due to its excellent optical properties, and can be used as a glass substitute due to its excellent surface touch, and has a high yield elongation. It is possible to implement an organic layer or an organic-inorganic hybrid layer that can be used in a flexible device.

In one embodiment of the present invention, each component may be in a mixed state, or each compound included in the components may be sequentially mixed.

According to an embodiment of the present invention, the diamine compound is, for example, oxydianiline (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMDA), bisaminophenoxybenzene (133APB), bisaminophenoxybenzene (134APB), bisaminophenoxyphenyl hexafluoropropane (4BDAF), bisaminophenyl hexafluoropropane (33- 6F), bisaminophenyl hexafluoropropane (44-6F), bisaminophenylsulfone (4DDS), bisaminophenylsulfone (3DDS), bistrifluoromethyl benzidine (TFDB), cyclohexanediamine (13CHD), cyclo Hexanediamine (14CHD), bisaminophenoxyphenylpropane (6HMDA), bisaminohydroxyphenyl hexafluoropropane (DBOH), bisaminophenoxydiphenyl sulfone (DBSDA), bis(4-aminophenyl)flu It may include at least one selected from orene (FDA) and bis (4-amino-3 fluorophenyl) fluorene (F-FDA). As the diamine, the compounds described above may be used alone, or two or more compounds may be mixed and used.

The polyimide-based film prepared by using components including a diamine compound and a dicarbonyl compound may be a polyimide-based film having an amide repeating unit.

The first dicarbonyl compound according to an embodiment of the present invention may include at least one of a first aromatic dicarbonyl compound and a first aliphatic dicarbonyl compound.

The second dicarbonyl compound according to an embodiment of the present invention may include at least one of a second aromatic dicarbonyl compound and a second aliphatic dicarbonyl compound.

The first aromatic dicarbonyl compound and the second aromatic dicarbonyl compound may be each independently selected from compounds represented by Formula 1 below.

[Formula 1]

In Formula 1, R ₁ is a single bond, arylene (*-Ar-*), oxyarylene (*-O-Ar-*), cycloalkylene (*-CAL-*), or oxycycloalkylene ( *-O-CAL-*), X ₁ and X ₂ each independently represent hydrogen, a hydroxyl group (-OH) or a halogen element, and X ₃ represents hydrogen or a halogen element. Here, "Ar" may represent a substituted or unsubstituted arylene group, and CAL may represent a cycloaliphatic group.

As the arylene group, for example, there is a phenylene group represented by the following formula (2).

[Formula 2]

According to an embodiment of the present invention, there is an unsubstituted allylene group, for example, a phenylene group represented by the formula (2).

Also, as the substituted arylene group, there is, for example, a phenylene group in which hydrogen (H) of the benzene ring is substituted with a halogen element. More specifically, as the substituted arylene group, there is a chlorophenylene group in which hydrogen (H) of the benzene ring is substituted with chlorine (Cl).

In Formula 1, _{at least one of X 1} and X ₂ may be a halogen element, and the halogen element may be a chlorine (Cl) atom. In addition, X ₃ may be a chlorine atom (Cl).

The first aromatic dicarbonyl compound and the second aromatic dicarbonyl compound according to an embodiment of the present invention are each independently a compound represented by the following Chemical Formula 3, a compound represented by the following Chemical Formula 4, and a compound represented by the following Chemical Formula 5 , a compound represented by the following Chemical Formula 6, a compound represented by the following Chemical Formula 7, a compound represented by the following Chemical Formula 8, and a compound represented by the following Chemical Formula 9.

[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

According to an embodiment of the present invention, the first aromatic dicarbonyl compound and the second aromatic dicarbonyl compound are, for example, terephthaloyl chloride (TPC) (Formula 3), terephthalic acid (TPA) ( Formula 4), isophthaloyl dichloride (IPC) (Formula 5), 1,1'-biphenyl-4,4'-dicarbonyl dichloride (1,1'-biphenyl-4,4'-dicarbonyl dichloride) , BPDC) (Formula 6), 4,4'-oxybisbenzoyl chloride (4,4'-oxybisbenzoyl chloride, ODBC) (Formula 7) and 2-chloroterephthaloyl dichloride (2-chloroterephthaloyl dichloride) at least one may be included independently of each other.

In addition, the first aliphatic dicarbonyl compound and the second aliphatic dicarbonyl compound according to an embodiment of the present invention include, for example, a compound represented by the following Chemical Formula 10, a compound represented by the following Chemical Formula 11, and a compound represented by the following Chemical Formula 12 At least one of the compound represented by the compound and the compounds represented by the following Chemical Formula 13 may be included independently of each other. The compounds represented by the following formulas 10 to 13 may be referred to as alicyclic compounds,

[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

According to an embodiment of the present invention, the first dicarbonyl compound may be included in a ratio of 55 to 90 moles based on 100 moles of the diamine compound. According to the content range of the first dicarbonyl compound described above, it is possible to effectively improve optical properties, gloss, and thermal conductivity by providing the maximum value of the amide repeating unit constituting the polyimide-based film, and below the lower limit, gloss, In addition to overall poor optical properties such as thermal conductivity and light transmittance, yellowness characteristics are not implemented, and when the upper limit is exceeded, glossiness, thermal conductivity, and yellowness characteristics are not implemented.

In addition, the first dicarbonyl compound may be included in a ratio of 55 to 85 moles or 60 to 80 moles based on 100 moles of the diamine compound.

According to an embodiment of the present invention, the second dicarbonyl compound may be included in a ratio of 10 to 40 moles based on 100 moles of the diamine compound. According to the content range of the second dicarbonyl compound described above, the above-described first dicarbonyl compound compensates for the maximum amount of the amide repeating unit constituting the polyimide-based film, thereby providing optical properties, glossiness, and thermal conductivity. can be effectively improved, and if the lower limit is less than the lower limit, the glossiness is poor and the yellowness characteristic is not implemented, and when the upper limit is exceeded, the glossiness and thermal conductivity, the yield elongation and the yellowness characteristic are not implemented.

In addition, the second dicarbonyl compound may be included in a ratio of 15 to 35 moles, 15 to 30 moles, or 20 to 30 moles based on 100 moles of the diamine compound.

In particular, the first dicarbonyl compound and the second dicarbonyl compound are the sum of the first dicarbonyl compound and the second dicarbonyl compound in a ratio of 80 to 98 moles based on 100 moles of the diamine compound. It is more preferable to include it in consideration of the balance of physical properties.

In addition, the combined content of the first dicarbonyl compound and the second dicarbonyl compound may be included in a ratio of 80 to 90 moles, 85 to 98 moles, or 85 to 90 moles based on 100 moles of the diamine compound. .

As described above, according to an embodiment of the present invention, an aromatic dianhydride compound may be further included as components constituting the polyimide-based film. When the components further include an aromatic dianhydride compound in addition to the diamine compound and the dicarbonyl compound, the polyimide-based film may have a polyamide-imide copolymer structure having an imide repeating unit and an amide repeating unit.

Since a film having a polyamide-imide copolymer structure has an imide repeating unit, in an embodiment of the present invention, a film having a polyamide-imide copolymer structure is also referred to as a polyimide-based film. Accordingly, the polyimide-based film according to an embodiment of the present invention may be a polyimide film, a polyamide-imide film, or a polyamide film.

The aromatic dianhydride compound is, for example, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), biphenyl tetracarboxylic dianhydride (BPDA), 4 -(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA), pyromellitic acid dianhydride ( PMDA), benzophenone tetracarboxylic dianhydride (BTDA), oxydiphthalic dianhydride (ODPA), biscarboxyphenyl dimethyl silane dianhydride (SiDA), bis dicarboxyphenoxy diphenyl sulfide dianhydride ( BDSDA), sulfonyl diphthalic anhydride (SO ₂ DPA), isopropylideneiphenoxy bis phthalic anhydride (6HBDA), cyclobutanedianhydride (CBDA), cyclopentanedianhydride (CPDA), It may include at least one selected from cyclohexanedianhydride (CHDA) and bicyclohexanedianhydride (HBPDA).

According to an embodiment of the present invention, the aromatic dianhydride compound may be included in a ratio of 20 moles or less, or 1 to 20 moles, based on 100 moles of the diamine compound. According to the content range of the above-described aromatic dianhydride compound, the above-described first dicarbonyl compound and the above-described second dicarbonyl compound are combined with a diamine compound to implement an amide structure, but are already combined with a diamine compound By implementing a de-structured structure, it is possible to provide gloss and thermal conductivity more effectively while providing gloss properties and mechanical properties. If the upper limit is exceeded, not only optical properties such as glossiness and light transmittance are generally poor, but also yellowness properties are not implemented. and the yield elongation is also poor.

In addition, the aromatic dianhydride compound may be included in a ratio of 2 to 20 moles or 3 to 20 moles based on 100 moles of the diamine compound.

According to an embodiment of the present invention, the components further include a filler, wherein the filler may be included in the range of 5 to 80 parts by weight based on 100 parts by weight of the diamine compound, for example, but is not limited thereto.

Examples of the filler include organic particles and inorganic particles, and inorganic particles are particularly preferable. Examples of inorganic particles include particles of metal oxides such as silica, zirconia, alumina, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, cerium oxide, and metals such as magnesium fluoride and sodium fluoride. and fluoride particles. Among them, silica particles, zirconia particles, and alumina particles are preferable, and silica particles are particularly preferable from the viewpoint of easily suppressing deterioration of optical properties due to repeated collisions of objects. These fillers can be used individually or in combination of 2 or more types.

The primary particle diameter of the filler, preferably silica particles, is, for example, 1 nm or more, preferably 3 nm or more, more preferably 5 nm or more, and most preferably 7 nm or more, for example 25 nm or less, preferably 20 nm or less, more preferably Preferably it is 15 nm or less, Most preferably, it is 12 nm or less, A combination of these upper limit and a lower limit may be sufficient. If the primary particle diameter of the filler is more than the lower limit, it is easy to suppress aggregation of silica particles to improve the optical properties of the optical film, and if it is less than the upper limit, it is easy to suppress aggregation of silica particles to improve the optical properties of the optical film If it is below the said upper limit, it will be easy to suppress the fall of the optical characteristic by the repeated collision of an object. The primary particle diameter of a filler can be measured by BET method. Moreover, you may measure the primary particle diameter (average primary particle diameter) of a filler by image analysis with a transmission electron microscope (TEM) or a scanning electron microscope (SEM).

According to an embodiment of the present invention, the polyimide-based film may be calculated from glossiness and thermal conductivity as a variable indicating a surface touch feeling. For example, the gloss value measured at an angle of 20 degrees by the ASTM D523 measurement method and the thermal conductivity value measured with the LFA467 (ZETZSCH company) equipment by the ASTM E1461 measurement method are measured. Since it has an arbitrary absolute value of 500, it is possible to quantify the surface touch feeling by multiplying the value obtained by subtracting the G value of the measured sample with the thermal conductivity to quantify the surface touch feeling, and it will be described later that the numerically calculated value and the value obtained as a result of the sensory test match the result. It can be confirmed through the example.

If the calculated value of the surface touch feeling of the polyimide-based film is too low, the gloss may be poor, and if it is too high, the thermal conductivity may be poor.

The calculated value of Equation 1 presented according to an embodiment of the present invention may be referred to as a value obtained by digitizing the touch feeling of the surface of the polyimide-based film.

A small calculated value of Equation 1 of the polyimide-based film can be interpreted as a small change in specular reflection at each point on the surface of the polyimide-based film. A small change in specular reflection can be interpreted as a relatively large amount of diffuse reflection, and therefore, when the calculated value is smaller than the range specified in the present invention, it can be said that the touch feeling of the polyimide-based film surface is less excellent. .

In addition, the fact that the calculated value of Equation 1 of the polyimide-based film is large can be interpreted as a large change in heat conduction at each point on the surface of the polyimide-based film. A large change in heat conduction may mean that it is difficult to provide a touch feeling like glass with a small change in heat conduction.

According to an embodiment of the present invention, the polyimide-based film may have a surface touch feeling according to Equation 1 below 30.6 or more.

[Equation 1]

Surface touch = T x (500-G)

(In the above formula, T is the thermal conductivity value (unit W / mK) measured with the LFA467 (ZETZSCH company) equipment by the ASTM E1461 measurement method, and G is the gloss value (unit GU) measured at an angle of 20 degrees by the ASTM D523 measurement method )

When the polyimide-based film according to an embodiment of the present invention satisfies Equation 1, it has less diffuse reflection and excellent flatness, and the polyimide-based film or a polyimide-based film body including the same is used as a cover window of a display device It provides a glass-like touch feeling.

As a specific example of the polyimide-based film, it is more preferable that the surface touch feeling of Equation 1 is within the range of 30.6 to 41.8.

According to an embodiment of the present invention, the thickness of the polyimide-based film may have various thicknesses. The polyimide-based film may have a thickness of, for example, 10 to 250 μm, and more specifically, may have a thickness of 10 to 100 μm.

In addition, the polyimide-based film of the present invention has excellent optical properties. For example, the polyimide-based film according to an embodiment of the present invention may have a gloss of 230 to 260GU based on a film thickness of 50±2 μm. In the above range, it is possible to implement an organic layer or an organic-inorganic hybrid layer having an excellent surface touch feeling.

In addition, the polyimide-based film according to an embodiment of the present invention may have a thermal conductivity of 0.12 to 0.18 W/mK based on a film thickness of 50±2 μm. In the above range, it is possible to implement an organic layer or an organic-inorganic hybrid layer having a touch feeling like glass having a small change in thermal conductivity.

In addition, the polyimide-based film according to an embodiment of the present invention, based on a film thickness of 50±2 μm, a haze of 2.0% or less, an optical transmittance of 89% or more at a wavelength of 380 to 780 nm, and 4.0 or less It may have a yellowness. More specifically, according to an embodiment of the present invention, based on a thickness of 50±2 μm, the polyimide-based film may have a haze of 0.2 to 0.3%. Within the above range, an organic layer or an organic-inorganic hybrid layer having excellent optical properties may be implemented.

In addition, the polyimide-based film according to an embodiment of the present invention has, based on a film thickness of 50±2㎛, an elongation at yield in the machine direction (MD) of 1.8% or more, and an elongation at yield in the width direction (TD) of 1.8% or more. can have More specifically, according to an embodiment of the present invention, based on a thickness of 50±2 μm, the polyimide-based film may have a yield elongation in the machine direction (MD) and the width direction (TD) of 1.8% to 2.0%. have. In the above range, it is possible to implement an organic layer or an organic-inorganic hybrid layer that can be used in a flexible device.

As such, the polyimide-based film according to an embodiment of the present invention has excellent surface properties as well as excellent optical properties because the surface touch value calculated from the gloss and thermal conductivity is within a specific range. Therefore, the polyimide-based film according to the present invention can be used as a cover window of a display device, a transparent protective film, a light diffusion plate, and a liquid crystal alignment film, can be used as a base film for a hard coating film, and can be used as a substrate for a flexible display. can be used

In addition, the polyimide-based film according to an embodiment of the present invention may be used, for example, as a substitute for glass.

In addition, the polyimide-based film according to an embodiment of the present invention may be used, for example, as a base film of a polyimide-based film body.

That is, according to another embodiment of the present invention, a polyimide-based film body including the above-described polyimide-based film is provided.

On one side or both sides of the polyimide-based film, a primer film, a hardness-reinforced film, a flexible film, a fold-back film, a flexural strength reinforcement film, a visibility improvement film, a barrier film, an antibacterial film, a water-repellent film, an anti-fingerprint film, a reflection It is possible to provide a film body in which optical properties and mechanical properties are reinforced by including one or more coating layers selected from an anti-aging film and a film providing a smooth touch feeling.

For example, the coating layer may be formed by co-extrusion or extrusion lamination.

According to another embodiment of the present invention, there is provided a window member including a glass cover and a polyimide-based film provided on at least one surface of the glass cover. In this case, the polyimide-based film may be provided with the above-described polyimide-based film body to provide a window member, and may be applied to various electronic components other than the window member.

Hereinafter, a method of manufacturing a polyimide-based film according to an embodiment of the present invention will be described in detail.

The method of manufacturing a polyimide-based film according to an embodiment of the present invention includes a diamine compound, a first dicarbonyl compound, a second dicarbonyl compound compound, and, if necessary, an aromatic dianhydride compound, a filler, and the like. It includes the steps of preparing a liquid resin composition using the (S1), manufacturing a film in a gel state by molding the resin composition in a liquid state (S2), and drying the film in a gel state (S3) .

According to an embodiment of the present invention, first, a liquid resin composition is prepared by monomer components including a diamine compound, a first dicarbonyl compound, and a second dicarbonyl compound.

Since the diamine compound, the first dicarbonyl compound, and the second dicarbonyl compound have already been described, detailed descriptions thereof are omitted to avoid duplication.

A first solvent may be used for solution polymerization of the components. Specifically, the components may be reacted in the presence of a first solvent to prepare a polymer solution. An organic solvent may be used as the first solvent for solution polymerization.

There is no particular limitation on the type of the first solvent. As a first solvent, for example, m-cresol, N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), dimethylformamide (DMF), diethylformamide (DEF), dimethylacetamide (DMAc), diethyl acetamide (DEAc), acetone, ethyl acetate, propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (Propylene glycol monomethyl ether Acetate) , PGMEA) at least one solvent selected from may be used. In addition, a low boiling point solvent such as tetrahydrofuran (THF), chloroform, or a low water absorption solvent such as γ-butyrolactone may be used as the first solvent. The first solvent may be used alone or in combination of two or more depending on the purpose.

The content of the first solvent is not particularly limited. The first solvent may have a content of 50 to 95% by weight based on the total weight of the first polymer solution. More specifically, the first solvent may have a content of 70 to 90% by weight based on the total weight of the polymer solution.

The polyimide-based film prepared by using monomer components including the first dicarbonyl compound and the second dicarbonyl compound may have high thermal stability and mechanical properties, as well as a surface touch feeling.

According to an embodiment of the present invention, the components may further include an aromatic anhydride compound. When the monomer components further include an aromatic anhydride compound in addition to the diamine compound and the dicarbonyl compound, the polyimide-based film may have a polyamide-imide copolymer structure. In an embodiment of the present invention, a film having a polyamide-imide copolymer structure is also referred to as a polyimide-based film.

A polyimide-based film prepared by using monomer components including an aromatic anhydride compound may have high thermal stability and mechanical properties.

Since the aromatic anhydride compound has already been described, a description thereof will be omitted.

There is no particular limitation on the method applied to the step (S1) of preparing the liquid resin composition using the components. Here, the liquid resin composition can be said to be a liquid polyimide-based resin composition.

According to an embodiment of the present invention, in the step (S1) of preparing a liquid resin composition, the first step of preparing a polymer solution by reacting the components in the presence of a first solvent, a second solvent is added to the polymer solution, , a second step of preparing a polymer solid by filtration and drying, and a third step of dissolving the polymer solid in a third solvent.

If necessary, it is preferable to include a step of stabilizing the solution in the first or third step of preparing the polymer solution. Specifically, the polymer solution may be heated and maintained at least once at room temperature or below, or at a temperature of 5 to 15 degrees, and then the steps to be described later may be performed. When the polymer solution stabilization step is performed, it is advantageous to prepare a polyimide-based film having high gloss and low thermal conductivity, and it may also be easy to prepare a polyimide-based film satisfying a specific surface touch feeling range.

However, an embodiment of the present invention is not limited thereto, and a polyamic acid is prepared using components including a diamine compound, a first dicarbonyl compound, a second dicarbonyl compound, and, if necessary, an aromatic dianhydride compound. Then, thermosetting may be performed to prepare a polyimide-based resin composition. In addition, after adding a chemical curing agent to the polyimide-based polymer solution of polyamic acid, it is also possible to directly form (film) a polyimide-based film in the form of a film without proceeding with a filtration process using a second solvent.

In addition, the diamine compound may be divided and put in a mixed state with the first dicarbonyl compound, added in a mixed state with the second dicarbonyl compound, and may be added in a mixed state with the aromatic dianhydride compound if necessary. In this case, the content of the diamine compound to be divided may be divided and added at a ratio of 5 to 35 moles, 15 to 40 moles, and 50 to 80 moles, among a total of 100 moles of the diamine compound to be added. A total of 100 moles can be added at once without being divided, and in this case, properties such as optical and glossiness may be better.

To prepare a liquid resin composition, first, the components are polymerized to prepare a polymer solution. In this case, the polymer solution may include a polyamic acid solution. At this time, there is no particular limitation on the reaction conditions. The reaction temperature may be adjusted, for example, in the range of -10 to 80° C., and the reaction time may be adjusted to 2 to 48 hours. The step of preparing the first polymer solution may be performed in an inert gas atmosphere such as argon or nitrogen.

Next, the imidization process for the polymer solution may proceed. At this time, the polyamic acid contained in the polymer solution may be imidized.

For imidization, a thermal imidization method, a chemical imidization method, or a method using a thermal imidization method and a chemical imidization method in combination can be applied.

According to an embodiment of the present invention, a chemical imidization method may be applied. Chemical imidization is a method in which a dehydrating agent such as acetic anhydride and the like and an imidization catalyst such as isoquinoline, β-picoline, pyridine or tertiary amine are applied to a polymer solution.

A thermal imidation method may be used together with a chemical imidation method.

When the thermal imidization method and the chemical imidization method are used together, imidization may be performed by adding a dehydrating agent and an imidization catalyst to the polymer solution and heating at 20 to 180° C. for 1 to 12 hours.

Next, a second solvent is added to the polymer solution, filtered and dried to prepare a polymer solid.

According to an embodiment of the present invention, the second solvent is used to obtain the solid content of the polyimide resin. Therefore, as the second solvent, a solvent that does not dissolve the polyamic acid contained in the polymer solution may be used, and the polyimide-based polymer solid may be precipitated due to the difference in solubility.

A solvent having a lower polarity than the first solvent may be used as the second solvent. As the second solvent, for example, at least one selected from water, alcohols, ethers and ketones may be used.

There is no particular limitation on the content of the second solvent. 5 to 20 times the weight of the second solvent based on the weight of the polyamic acid contained in the polymer solution may be used.

Conditions for drying after filtering the obtained polymer solid content are determined in consideration of the boiling points of the second solvent and the first solvent remaining in the polymer solid content. For example, the polymer solids may be dried at a temperature of 50 to 150° C. for 2 to 24 hours.

Next, the polymer solid is dissolved in the third solvent to prepare a liquid resin composition. The liquid resin composition may be referred to as a polyimide-based resin composition.

According to an embodiment of the present invention, the third solvent may be the same as the first solvent. Thus, as a third solvent, for example, m-cresol, N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), dimethylformamide (DMF), diethyl Formamide (DEF), dimethylacetamide (DMAc), diethyl acetamide (DEAc), acetone, ethyl acetate, propylene glycol monomethyl ether (PGME) and propylene glycol monomethyl ether acetate (Propylene glycol monomethyl) At least one selected from ether acetate, PGMEA) may be used.

The prepared liquid resin composition prepared as described above may have a viscosity of 100 to 300,000 cPs. When the viscosity of the liquid resin composition is less than 100 cPs, it may be difficult to cast the liquid resin composition to form a film, and due to the low molecular weight, it may be difficult to peel the film formed by casting from the casting substrate. can On the other hand, when the viscosity of the liquid resin composition exceeds 300,000 cPs, the pressure applied during the casting process increases due to the high viscosity, which may be disadvantageous in terms of the process.

More specifically, the liquid resin composition may have a viscosity of 1,000 to 250,000 cPs. When the liquid resin composition has a viscosity of 1,000 to 250,000 cPs, it is easy to cast the liquid resin composition to form a film, and it is also easy to dry. For example, when the viscosity of the liquid resin composition is 1000 cPs or more, there is no difficulty in casting the liquid resin composition to form a film, and the film formed by casting can be peeled from the casting substrate without difficulty. In addition, when the viscosity of the liquid resin composition is 250,000 cPs or less, the casting process may proceed without increasing the pressure for casting the liquid resin composition more than necessary.

According to an embodiment of the present invention, the liquid resin composition may have a viscosity of 1000 to 30,000 cPs.

According to an embodiment of the present invention, the content of the solids contained in the liquid resin composition may be adjusted in the range of 5 to 30% by weight based on the total weight of the liquid resin composition.

Next, a film in a gel state is prepared by the liquid resin composition. The film in a gel state can be said to be an uncured polyimide-based film in a gel state.

A casting method may be applied to prepare a film in a gel state.

Specifically, according to an embodiment of the present invention, the step of preparing the film in a gel state includes casting a liquid resin composition on a support.

The casting method is not particularly limited, and a casting method known in the art may be applied. A film in a gel state is produced by casting.

A glass plate, an aluminum substrate, a circular stainless belt, a stainless drum, or a heat-resistant polymer film may be used as the support.

According to an embodiment of the present invention, the film in a gel state means an uncured polyimide-based film in which curing is not completed. In an embodiment of the present invention, even if the curing is partially made, if the curing is not completed, the film is referred to as a gel film or an uncured polyimide-based film.

According to an embodiment of the present invention, drying is carried out to remove the solvent contained in the film in a gel state, for example, primary drying for 2 to 20 minutes at a wind speed of 1.0 m / s or less at 50 to 150 ° C. .

In general, since a solvent having a high boiling point is used in the manufacturing process of the liquid resin composition, it can be considered that a strong wind speed must be applied to the cast gel film in order to efficiently remove the solvent.

In general, the drying efficiency increases as the temperature increases. On the other hand, when the temperature during primary drying increases and the drying temperature approaches the boiling point of the solvent, bubbles may be generated on the surface of the polyimide-based film due to sudden volatilization of the solvent, and bending may occur, so that polyimide The surface uniformity of the system film is reduced.

Accordingly, in the primary drying step, drying is performed at a temperature of 50° C. or higher to secure drying efficiency, and drying is performed at a temperature of 150° C. or lower to prevent sudden volatilization of the solvent. In order to improve drying efficiency, primary drying may be performed in a temperature range of 70 to 150°C.

According to an embodiment of the present invention, after the primary drying, the residual solvent content ratio of the uncured polyimide film may be adjusted to 50% by weight or less. More specifically, after the primary drying, the residual solvent content ratio of the uncured polyimide film may be adjusted to 40 wt% or less.

According to an embodiment of the present invention, after the primary drying step, the secondary drying step of the film in a gel state at 70 to 140 ℃ at a wind speed of 1.0 to 5.0 m / s may be carried out. If the wind speed of the secondary drying is less than 1.0 m/s or the temperature is less than 70°C, the speed of the secondary drying may be excessively reduced. When the rate of secondary drying is excessively reduced, the efficiency of the process is reduced, and physical properties of the polyimide-based film may be changed due to an increase in drying time.

Due to the primary drying, since the gel film is dried and hardened to some extent, there is little possibility that the surface properties of the gel film will be changed by the wind applied in the secondary drying step. The wind speed in the secondary drying step may be adjusted, for example, in the range of 1.5 to 5.0 m/s, and more specifically, the wind speed in the secondary drying step may be adjusted in the range of 1.6 to 3.0 m/s. In addition, the temperature in the secondary drying step may be adjusted in the range of 100 to 140 ℃.

According to an embodiment of the present invention, after the secondary drying step, the first heat treatment of the film in the gel state may be performed.

In the first heat treatment step, a known thermosetting process may be applied. For example, the film in a gel state may be heat-treated at a temperature of 100 to 500° C. for 1 minute to 1 hour. By this heat treatment, the film in the gel state may be thermosetted to complete the polyimide-based film. The first heat treatment step is also called a thermosetting step.

The first heat treatment step may be made in a support, or may be made in a separate heat treatment support. For example, after secondary drying, after the film in a gel state is separated from the support, the primary heat treatment may be performed after being fixed to the support for the primary heat treatment. A pin-type frame or a clip-type frame may be used to support the film in a gel state.

According to an embodiment of the present invention, the content of the volatile component remaining in the polyimide-based film after the first heat treatment may be adjusted to be 5 wt% or less.

According to an embodiment of the present invention, the secondary heat treatment may be performed in a state in which a predetermined tension is applied to the polyimide-based film that has been subjected to the primary heat treatment. The residual stress inside the polyimide-based film may be removed by the secondary heat treatment.

When the secondary heat treatment is performed, the coefficient of thermal expansion of the polyimide-based film may be reduced. For example, residual stress to shrink in the polyimide-based film may be generated by the secondary heat treatment, and thermal expansion may be reduced, and a hysteresis of the thermal expansion coefficient may be reduced in the polyimide-based film.

The tension and temperature applied to the secondary heat treatment have a correlation with each other. Therefore, the tension condition may vary depending on the temperature applied to the secondary heat treatment.

The secondary heat treatment may be performed at a temperature of 100 to 500° C. for 1 minute to 1 hour, and may be performed at a temperature of 250 to 350° C. for 2 to 15 minutes.

Hereinafter, definitions of substituents used in the chemical formulas of the present specification will be described.

The term “alkyl,” as used in the formula, refers to a fully saturated branched or unbranched (or straight-chain or linear) aliphatic hydrocarbon.

Non-limiting examples of "alkyl" include methyl, ethyl, i-propyl, isopropyl, i-butyl, isobutyl, sec-butyl, i-pentyl, isopentyl, neopentyl, i-hexyl, 3-methylhexyl , 2,2-dimethylpentyl, 2,3-dimethylpentyl, i-heptyl, and the like.

The term "cycloalkyl," as used in the formula, refers to an alkyl comprising one or more rings.

The term "oxycycloalkyl" used in the formula refers to -O-cycloalkyl, and the "cycloalkyl" group is as described above.

The term "halogen atom" is fluorine, bromine, chlorine, iodine, and the like.

The term "aryl" as used in the formula, used alone or in combination, refers to an aromatic hydrocarbon containing one or more rings.

The term "aryl" also includes groups in which an aromatic ring is fused to one or more cycloalkyl rings. Non-limiting examples of "aryl" include phenyl, naphthyl, tetrahydronaphthyl, and the like.

The term "oxyaryl" used in the formula refers to -O-aryl, and the "aryl" group is as described above.

The term "arylene" as used in the formula means a bivalent aromatic hydrocarbon corresponding to "aryl". Non-limiting examples of "allylene" include phenylene, naphthylene, and the like.

The term "oxyarylene" as used in the formula means a bivalent aromatic hydrocarbon corresponding to "oxyaryl".

The term "cycloalkylene" as used in the formula means a bivalent aliphatic hydrocarbon corresponding to "cycloalkyl".

The term "oxycycloalkylene" as used in the formula means a bivalent aliphatic hydrocarbon corresponding to "oxycycloalkyl".

The substituent of the term "substituted arylene group" as used herein is a halogen, a hydroxy group, a C1 to C5 alkyl group, a C1 to C5 alkoxy group, or a combination thereof.

Hereinafter, the present invention will be described in more detail with reference to specific preparation examples and examples. However, the scope of the present invention is not limited by the following Preparation Examples or Examples. The amount of the first dicarbonyl compound and the second dicarbonyl compound presented as an example may be changed within an error range depending on the viscosity value.

Specific specifications of the components used in Preparation Examples are as follows.

(A) Diamine compound: bistrifluoromethyl benzidine

(B) first dicarbonyl compound: a compound represented by the following formula (3)

[Equation 3]

(C) second dicarbonyl compound: a compound represented by the following formula (5)

[Equation 5]

(D) Aromatic dianhydride compound: 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride

(E) first solvent: N,N-dimethylacetamide (DMAc)

(F) Second solvent: methanol

(G) Third solvent: N,N-dimethylacetamide (DMAc)

(H) Filler: amorphous silica particles with OH groups bonded to the surface

<Production Example 1>

While passing nitrogen through a 1L reactor equipped with a stirrer, nitrogen injection device, dropping funnel, temperature controller and cooler, 767.433 g of (E) component was filled, and then the temperature of the reactor was adjusted to 25 ° C., (A) component 64.046 g (0.2 mol) was dissolved and the reactor temperature was lowered to 10 °C, and the temperature of the solution was maintained at 8 °C again.

Here, 24.362 g (0.12 mol) of component (B) was added while maintaining the solution temperature of 8° C., followed by reaction. The temperature of the solution was increased by the heat of reaction, and then the solution temperature was decreased to 8°C again. When the solution temperature decreased to 8°C, 16.242 g (0.08 mol) of component (C) was added and reacted. Then, the reactor temperature was raised to 25° C. and reacted for 12 hours to obtain a polymer solution having a solid content of 12 wt%. The polymer solution may include polyamic acid. Accordingly, the polymer solution is also referred to as a polyamic acid solution.

20L of component (F) was added to the obtained first polymer solution to precipitate solids, and the precipitated solids were filtered and pulverized, washed again with 2L of component (F), and dried at 100° C. in a vacuum for 6 hours to form a powder of polyimide-based polymer solid content was obtained.

The obtained polyimide-based polymer solid content was re-dissolved in the third solvent of component (G) to prepare a liquid resin composition having a solid content of 12 wt%. The liquid resin composition is also called a polyimide-based resin composition. Here, the polyimide-based resin composition is a polyamide resin composition.

<Production Example 2>

While passing nitrogen through a 1L reactor equipped with a stirrer, nitrogen injection device, dropping funnel, temperature controller and cooler, 781.585 g of (E) component was filled, and then the temperature of the reactor was adjusted to 25 ° C., (A) component 64.046 g (0.2 mol) was dissolved and the solution was maintained at 25°C. Here, (D) component 3.554g (0.008mol) was added and stirred for a certain time to dissolve and react. At this time, the reactor temperature was lowered to 10 °C, and the temperature of the solution was maintained at 8 °C again. And (B) component 31.265g (0.154mol) and (C) component 7.715g (0.038mol) were added and reacted at 25°C for 12 hours to obtain a polymer solution having a solid content of 12% by weight.

1.39 g of pyridine and 1.80 g of acetic anhydride were added to the obtained polymer solution, stirred for 30 minutes, stirred at 70° C. for 1 hour, cooled to room temperature, (F) component 20L was added to precipitate the solid, and the precipitated After the solid content was filtered and pulverized, it was washed again with 2L of component (F), and then dried at 100° C. in a vacuum for 6 hours to obtain a powdery polyimide-based polymer solid. The obtained polyimide-based polymer solid content was re-dissolved as component (G) to prepare a liquid resin composition having a solid content of 12 wt%. The liquid resin composition is also called a polyimide-based resin composition. Here, the polyimide-based resin composition is a polyamide-imide resin composition.

<Production Example 3>

(H) 10 g of component (E) was added to component (E) at a dispersion concentration of 2.54 wt% and ultrasonication was performed until the solvent became transparent, and then 49.94 g of the polyamide of the solid powder obtained in Preparation Example 1 was taken and 366.06 g of the silica particles were dissolved in dispersed N,N-dimethylacetamide (DMAc) to obtain a solution having a solid content of 12% by weight.

<Production Example 4>

The same process as in Preparation Example 2 is repeated, but (E) replaces 781.585 g of component usage with 838.194 g, (B) replaces 31.265 g of component usage with 14.211 g (0.07 mol) and (C) usage of component The same process as in Preparation Example 2 was repeated except that 7.715 g was replaced with 18.272 g (0.09 mol) and 3.554 g of component (D) was replaced with 17.770 g (0.04 mol).

<Preparation Example 5>

The same process as in Preparation Example 2 is repeated, but (E) replaces 781.585 g of component used with 795.738 g, (B) replaces 31.265 g of component with 37.356 g (0.184 mol) and (C) does not use component and (D) the same process as in Preparation Example 2 was repeated except that 3.554 g of the component used was replaced with 7.108 g (0.016 mol).

<Preparation Example 6>

The same process as in Preparation Example 2 is repeated, but (E) replaces 781.585 g of component used with 838.194 g, (B) replaces 31.265 g of component with 32.483 g (0.16 mol) and (C) does not use component and (D) the same process as in Preparation Example 2 was repeated except that 3.554 g of the component used was replaced with 17.770 g (0.04 mol).

<Production Example 7>

Repeat the same process as in Preparation Example 2, but replace 781.585 g of component (E) with 802.814 g of usage, (B) replace 31.265 g of component with 12.181 g (0.06 mol) and (C) usage of component The same process as in Preparation Example 2 was repeated except that 7.715 g was replaced with 24.362 g (0.12 mol) and 3.554 g of component (D) was replaced with 8.885 g (0.02 mol).

<Preparation Example 8>

The same process as in Preparation Example 2 is repeated, but (E) replaces 781.585 g of component usage with 908.955 g, (B) replaces 31.265 g of component with 22.332 g (0.11 mol) and (C) usage of component The same process as in Preparation Example 2 was repeated except that 7.715 g was replaced with 2.030 g (0.01 mol) and 3.554 g of component (D) was replaced with 35.540 g (0.08 mol).

<Examples 1 to 2>

After casting the solution obtained in Preparation Example 1 and Preparation Example 2 on a substrate to prepare a film in a gel state (uncured polyimide film in a gel state), at 80° C., at a wind speed of 0.2 m/s After primary drying for 20 minutes, the wind speed was increased to 1.6 m/s, and the gel film was dried for 10 minutes at 140°C.

After the gel film was mounted on a pin type tenter, the temperature was increased from 140° C. to 300° C. and the first heat treatment was performed for 1 hour. The film in the gel state was cured by the primary heat treatment to prepare a polyimide-based film.

The polyimide-based film prepared in Example 1 was a polyamide film. The polyimide-based film prepared in Example 2 was a polyamide-imide film.

The polyimide-based film prepared by the primary heat treatment was removed from the tenter frame, and the residual stress in the film was removed by secondary heat treatment at 260° C. for 5 minutes again. The obtained polyimide-based film had a thickness of 50 μm. , were referred to as Examples 1 and 2, respectively.

<Example 3>

After the solution obtained in Preparation Example 3 was applied to a stainless plate and dried with hot air at 130° C. for 30 minutes, the film was peeled off the stainless plate and fixed to the frame with pins. At this time, the fixed frame was stretched by 115% in the machine direction and shrunk by 85% in the width direction.

Thereafter, the frame to which the film is fixed was heated slowly from 140° C. to 300° C. for 1 hour (primary heat treatment), and then slowly cooled and separated from the frame to obtain a polyimide-based film. Then, as a final heat treatment (=second heat treatment) process, a second heat treatment was performed at 260° C. for 5 minutes. At this time, the machine direction stress in the final heat treatment process was set to 80 N/mm ² to achieve additional stretching and heat setting in the machine direction. The polyimide-based film prepared in Example 3 was a polyamide film.

The polyimide-based film prepared at this time had a thickness of 50 μm.

<Example 4>

A primer film was laminated on the polyimide-based film obtained in Example 1 as follows.

First, as a transparent material layer, 25 parts by weight of nonyl acrylate, 10 parts by weight of 2-hydroxylethyl acrylate, 15 parts by weight of isobornyl acrylate, 15 parts by weight of hexanediol diacrylate, and phosphorus in 100 parts by weight of urethane acrylate. 3 parts by weight of a pin-based photoinitiator was added and stirred at room temperature for 1 hour.

Then, filtered and filtered to prepare a transparent material layer solution.

In addition, as a transparent adhesive layer, 5 parts by weight of nonyl acrylate, 5 parts by weight of 2-hydroxylethyl acrylate, 5 parts by weight of isobornyl acrylate, 3 parts by weight of hexanediol diacrylate for 100 parts by weight of 2-ethylhexyl acrylate , and 1 part by weight of a phosphine-based photoinitiator and stirred at room temperature for 1 hour.

Then, it was filtered to prepare a transparent adhesive layer solution.

The transparent material layer solution and the transparent adhesive layer solution were applied to a thickness of 10 μm and 20 μm, respectively, on the polyimide-based film obtained in Example 1 using a co-extrusion T die.

The applied multilayer liquid film was UV-cured to form a coating layer.

<Comparative Examples 1 to 5>

A polyimide-based film was prepared in the same manner as in Example 1, but the same method as in Example 1 was repeated except that the solution of Preparation Example 1 was replaced with the solution obtained in Preparation Examples 4 to 8, respectively. .

The physical properties of the polyimide-based films prepared in Examples and Comparative Examples were measured in Table 1 below, and the results are shown in Table 1.

(1) Measuring the thickness of the film

Using an Anritsu Electronic Micrometer, the thickness of the polyimide-based film prepared in Examples and Comparative Examples was measured. The thickness variation due to the device is ±0.5% or less.

(2) optical transmittance

For the polyimide-based films prepared in Examples and Comparative Examples, average optical transmittance was measured in a wavelength range of 380 to 780 nm using a UV spectrometer (Cotica Minolta CM-3700d).

(3) Yellowness (Yellow Index, Y.I.)

Yellowness of the polyimide-based films prepared in Examples and Comparative Examples was measured according to ASTM E313 standard using a UV spectrometer (Cotica Minolta CM-3700d).

(4) Haze

Haze of the polyimide-based films prepared in Examples and Comparative Examples was measured using Haze Meter HM-150.

(5) Thermal conductivity measurement:

According to ASTM E1461 standard using NETZSCH LFA 447, the thermal conductivity of the polyimide-based films prepared in Examples and Comparative Examples was measured.

(6) Glossiness: The surface of the polyimide film or primer film was measured at an angle of 20 degrees according to the standard (ASTM D523) using RHOPOINT IQ thopointinstruments' measuring equipment.

(7) Elongation at yield (Yield Strain, %): It was measured with a cross head speed of 5mm/min. and a grip interval of 100mm using a universal testing machine (UTM, Instron) as a standard (ASTM D882).

(8) Surface touch sensation (glass texture similarity) sensory test:

Sensory test of the film surface was conducted for 100 men and women between the ages of 30 and 50, and the sensory test results of 100 people who gave 10 points to the texture most similar to glass and 0 points to the poorest texture were averaged. For reference, if it was 8.0 or more, it was evaluated as good, and if it was less than 8.0, or if it was 8.0 or more, but Y.I. was 5.0 or more, it was evaluated as bad.

Thickness (μm) Glossiness (GU) haze thermal conductivity
(W/mK) yellowness Light transmittance (%) Sensory evaluation of surface touch Elongation at yield MD (%) TD(%) Example 1 50±1.6 252 0.2 0.14 3.0 89.08 8.8 1.91 1.91 Example 2 50±1.6 239 0.2 0.16 2.0 89.65 8.9 1.96 1.94 Example 3 50±1.6 245 0.2 0.12 2.7 89.39 8.9 1.93 1.92 Example 4 50±1.6 240 0.2 0.13 2.5 89.50 8.9 1.94 1.93 Comparative Example 1 50±1.6 280 0.3 0.11 5.7 87.65 9.0 1.75 1.73 Comparative Example 2 50±1.6 305 0.4 0.08 8.6 85.57 7.8 1.90 1.91 Comparative Example 3 50±1.6 283 0.2 0.12 4.5 88.00 7.8 1.89 1.89 Comparative Example 4 50±1.6 288 0.2 0.10 5.9 87.40 7.0 1.70 1.70 Comparative Example 5 50±1.6 295 0.3 0.13 6.8 86.98 8.0 1.79 1.77

[Equation 1]

Surface touch = T x (500-G)

(In Equation 1, T is a value (unit W / mK) of the thermal conductivity of the polyimide-based film surface measured by ASTM E1461 with LFA467 (ZETZSCH) equipment, and G is the glossiness of the polyimide-based film surface value determined at an angle of 20 degrees (unit GU) by ASTM D523 measurement method)

Glossiness (GU) thermal conductivity
(W/mK) Calculated value of Equation 1 Surface touch sensory test Surface touch sensory test evaluation Example 1 252 0.14 34.7 8.8 Great Example 2 239 0.16 41.8 8.9 Great Example 3 245 0.12 30.6 8.9 Great Example 4 240 0.13 33.8 8.9 Great Comparative Example 1 280 0.11 24.2 9.0 bad Comparative Example 2 305 0.08 15.6 7.8 bad Comparative Example 3 283 0.12 26.0 7.8 bad Comparative Example 4 288 0.10 21.2 7.0 bad Comparative Example 5 295 0.13 26.7 8.0 bad

Referring to Table 2, the polyimide-based film or film body of Examples 1 to 4, although the gloss and thermal conductivity measured on the film surface according to the components and usage amount included in manufacturing the film, are within a specific range, the gloss It can be seen that when the surface touch feeling calculated by Equation 1 is 30.6 or more, or 30.6 to 41.8 from the degree and thermal conductivity, it was evaluated as excellent in the surface touch sensation sensory test.

Therefore, it can be seen that the surface touch feeling of the polyimide-based film is affected by a slight difference in gloss and thermal conductivity of the polyimide-based film or film body.

Referring to Table 1, it can be seen that the polyimide-based films or film bodies of Examples 1 to 4 provide improved optical properties as a result of measuring physical properties such as yellowness, haze, and light transmittance.

On the other hand, Comparative Examples 1 to 5 showed poor or high glossiness characteristics such as haze even when the sensory evaluation of the surface touch sensation was equal.

In addition, referring to Table 1, it can be seen that the polyimide-based films or film bodies of Examples 1 to 4 provide machine-direction and width-direction properties of an appropriate level of elongation at yield for use in flexible electronic devices.

That is, the polyimide-based film or film body of the present invention has excellent optical properties, so that it is possible to implement an organic layer or an organic-inorganic hybrid layer capable of improving the physical properties of electronic devices including a window member, and the surface touch feeling is excellent. In addition, it is possible to implement an organic layer or an organic-inorganic hybrid layer that can be used in a flexible device due to high yield elongation.

As a result, the polyimide-based film (or polyimide-based film body) according to an embodiment of the present invention can be applied to various electronic devices. Accordingly, another embodiment of the present invention provides an electronic device including the polyimide-based film (or polyimide-based film body) according to the present invention. The polyimide-based film (or polyimide-based film body) according to the present invention may be applied, for example, as a cover window of an electronic device.

Claims (14)

a copolymer of a diamine compound, a first dicarbonyl compound and a second dicarbonyl compound component;
With respect to 100 moles of the diamine compound,
Contained in a ratio of 55 to 90 moles of the first dicarbonyl compound,
It contains the second dicarbonyl compound in a ratio of 10 to 45 moles,
A polyimide-based film having a surface touch feeling of 30.6 or more according to Formula 1 below:
[Equation 1]
Surface touch feeling = T x (500-G)
(In Equation 1, T is a value (unit W / mK) of the thermal conductivity of the polyimide-based film surface measured by ASTM E1461 with LFA467 (ZETZSCH) equipment, and G is the glossiness of the polyimide-based film surface value determined at an angle of 20 degrees (unit GU) by ASTM D523 measurement method) According to claim 1,
A polyimide-based film having a surface touch feeling of 30.6 or more and 41.8 or less according to Formula 1 above. According to claim 1,
A polyimide-based film comprising a sum of the first dicarbonyl compound and the second dicarbonyl compound in a ratio of 80 to 98 moles based on 100 moles of the diamine compound. According to claim 1,
The polyimide-based film includes an aromatic dianhydride compound, and the aromatic dianhydride compound is included in an amount of 20 moles or less with respect to 100 moles of the diamine compound. According to claim 1,
The diamine compound is oxydianiline (ODA), p-phenylenediamine (pPDA), m-phenylenediamine (mPDA), p-methylenedianiline (pMDA), m-methylenedianiline (mMDA), bisaminophenoxy Cy Benzene (133APB), Bis Aminophenoxy Benzene (134APB), Bis Amino Phenoxy Phenyl Hexafluoropropane (4BDAF), Bis Aminophenyl Hexafluoropropane (33-6F), Bis Amino Phenyl Hexafluoropropane (44) -6F), bisaminophenylsulfone (4DDS), bisaminophenylsulfone (3DDS), bistrifluoromethyl benzidine (TFDB), cyclohexanediamine (13CHD), cyclohexanediamine (14CHD), bisaminophenoxyphenylpropane (6HMDA), bis aminohydroxy phenyl hexafluoropropane (DBOH), bis amino phenoxy diphenyl sulfone (DBSDA), bis (4-aminophenyl) fluorene (FDA) and bis (4-amino-3) A polyimide-based film comprising at least one selected from fluorophenyl)fluorene (F-FDA). According to claim 1,
The first dicarbonyl compound includes at least one selected from a first aromatic dicarbonyl compound and a first aliphatic dicarbonyl compound,
The second dicarbonyl compound is a polyimide-based film comprising at least one selected from a second aromatic dicarbonyl compound and a second aliphatic dicarbonyl compound. 7. The method of claim 6,
The first aromatic dicarbonyl compound and the second aromatic dicarbonyl compound are each independently selected from the compounds represented by the following Chemical Formula 1 polyimide-based film.
[Formula 1]

wherein R ₁ is a single bond, arylene (*-Ar-*), oxyarylene (*-O-Ar-*), cycloalkylene (*-CAL-*), or oxycycloalkylene (*) -O-CAL-*) and
X ₁ and X ₂ are each independently hydrogen, a hydroxyl group (OH) or a halogen element, and X ₃ is hydrogen or a halogen element. 8. The method of claim 7,
The first aromatic dicarbonyl compound and the second aromatic dicarbonyl compound are each independently represented by a compound represented by the following Chemical Formula 3, a compound represented by the following Chemical Formula 4, a compound represented by the following Chemical Formula 5, and the following Chemical Formula 6 A polyimide-based film comprising at least one of a compound represented by a compound represented by the following Chemical Formula 7, a compound represented by the following Chemical Formula 8, and a compound represented by the following Chemical Formula 9.
[Formula 3]

[Formula 4]

[Formula 5]

[Formula 6]

[Formula 7]

[Formula 8]

[Formula 9]

7. The method of claim 6,
The first aliphatic dicarbonyl compound and the second aliphatic dicarbonyl compound are each independently represented by a compound represented by the following Chemical Formula 10, a compound represented by the following Chemical Formula 11, a compound represented by the following Chemical Formula 12, and a compound represented by the following Chemical Formula 13 A polyimide-based film comprising at least one of the compounds.
[Formula 10]

[Formula 11]

[Formula 12]

[Formula 13]

5. The method of claim 4,
The aromatic dianhydride compound is 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), biphenyl tetracarboxylic dianhydride (BPDA), 4- (2, 5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA), pyromellitic acid dianhydride (PMDA), benzo Phenone tetracarboxylic dianhydride (BTDA), oxydiphthalic dianhydride (ODPA), biscarboxyphenyl dimethyl silane dianhydride (SiDA), bis dicarboxyphenoxy diphenyl sulfide dianhydride (BDSDA), alcohol Ponyl diphthalic anhydride (SO ₂ DPA), isopropylideneiphenoxy bis phthalic anhydride (6HBDA), cyclobutanedianhydride (CBDA), cyclopentanedianhydride (CPDA), cyclohexanedianhydride A polyimide-based film comprising at least one selected from lide (CHDA) and bicyclohexanedianhydride (HBPDA). According to claim 1, based on the thickness of 50 ± 2㎛,
Glossiness of 230~260GU;
thermal conductivity of 0.12 to 0.18 W/mK;
Elongation at yield in the machine direction (MD) of 1.8% or more;
Elongation at yield in the transverse direction (TD) of 1.8% or more;
an optical transmittance of at least 89% at a wavelength of 380 to 780 nm;
haze of 0.3% or less; and
A polyimide-based film having a yellowness of 4.0 or less. 12. A polyimide-based film body comprising the polyimide-based film according to any one of claims 1 to 11,
On one side or both sides of the polyimide-based film, a primer film, a hardness-reinforced film, a flexible film, a fold-back film, a flexural strength reinforcement film, a visibility improvement film, a barrier film, an antibacterial film, a water repellent film, an anti-fingerprint film, a reflection A polyimide-based film body comprising at least one coating layer selected from an anti-aging film and a film providing a smooth touch. glass cover; and
A window member comprising a polyimide-based film provided on at least one surface of the glass cover,
The polyimide-based film is a window member that is the polyimide-based film according to claim 1 . glass cover; and
A window member comprising a polyimide-based film body provided on at least one surface of the glass cover,
The polyimide-based film body is a window member according to claim 12, wherein the polyimide-based film body is a window member.