KR102521984B1 - Method for manufacturing colorless and transparent polyimide film, and colorless and transparent polyimide film prepared by manufacturing method thereof - Google Patents

Abstract

The present invention relates to a polyimide film using a polyimide precursor, the polyimide film which is useful as a transparent film material or transparent flexible substrate material, and is particularly useful as a resin substrate material having high transparency, hardness, a low coefficient of thermal expansion (CTE), high heat resistance, etc. Additionally, the present invention relates to a method for manufacturing the above transparent polyimide film. The method for manufacturing the transparent polyimide film comprises a first step of producing amine-terminated polyamic acid; a second step of producing a polyimide precursor; and a third step of producing a polyimide film by casting the polyimide precursor on a support and imidizing the same.

Description

Method for manufacturing colorless and transparent polyimide film, and colorless and transparent polyimide film prepared by manufacturing method thereof

The present invention relates to a polyimide film using a polyimide precursor, which is useful as a transparent film material or a transparent flexible substrate material, and is particularly useful as a resin substrate material having high transparency, hardness, low coefficient of thermal expansion (CTE), and high heat resistance. it's about Further, the present invention relates to a method for producing the above transparent polyimide film.

With the rapid progress of light weight, thinness, and high performance of electronic devices, resins are being used as glass substitute materials for glass substrates, which are display panel substrates for conventional displays and touch panels. One promising material is polyimide.

These polyimides are used in the form of films.

On the other hand, polyamic acid, which is a polyimide precursor, which is a material of a polyimide film, has a problem in that it is difficult to increase the degree of polymerization due to an increase in viscosity due to a strong hydrogen bond. When the degree of polymerization is low, the thermal and mechanical properties are relatively low, making it difficult to achieve sufficient physical properties even after imidation, and it is difficult to apply the polyimide film to a transparent polyimide film used as a display window.

In order to overcome these disadvantages, prior literature has proposed polyamide imide. In the prior literature, in the reaction of diamine and this anhydride, an amine-terminated polyamic acid was prepared by using an excess of diamine and reacted with dicarbonyl chloride to obtain a polyamic acid containing an amide group, and polyamide imide by imidizing it with heat. Films are being manufactured (KR10-2251516B, KR10-1459178B, KR10-2013-0071650A1).

However, although the mechanical properties of the transparent polyimide film are excellent, a large amount of salt generated from hydrochloric acid is generated in the process of introducing an amide group, and a separate precipitation process is required to remove it, resulting in poor economic efficiency.

Therefore, it is currently expected that a useful transparent polyimide film having excellent mechanical properties and economic feasibility of a manufacturing process, and a manufacturing method thereof should be developed.

KR 102251516 B1) KR 101459178 B1) KR 1020130071650 A1)

An object of the present invention is to provide a method for producing a transparent polyimide film useful as a heat-resistant transparent resin substrate material having excellent dimensional stability, transparency, and heat resistance, and a polyimide film produced by the method in order to solve the above problems. to be

However, the problem to be solved by the present invention is not limited to the above-mentioned problem, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

The manufacturing method of the transparent polyimide film of the present invention,

A first step of preparing an amine-terminated polyamic acid;

A second step of preparing a polyimide precursor by reacting norbornene anhydride with the amine-terminated polyamic acid; and

and a third step of manufacturing a polyimide film by casting the polyimide precursor prepared in the second step on a support and imidating the precursor.

The terminal of the polyimide precursor prepared in step 2 may include both an amine group and a carboxylic acid containing a double bond.

In addition, the transparent polyimide film produced by the above manufacturing method,

550nm transmittance is more than 90%,

Haze of the film is 1% or less,

The CTE (Coefficient of Thermal Expansion) of the film is 55ppm/℃,

The pencil hardness is 2H,

It is characterized by a yellow index of 4.5 or less.

The manufacturing method of the transparent polyimide film of the present invention is easy to manufacture and has excellent manufacturing economics, and the polyimide film produced by the manufacturing method has excellent transparency and mechanical properties.

In addition, the transparent polyimide film obtained by the present invention can be used as a practical flexible heat-resistant transparent resin substrate material that can replace glass substrates in displays and touch panels and satisfies required characteristics such as dimensional stability. There are advantages to being

In the above, the present invention has been described in detail with preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications may be made by those skilled in the art within the scope of the technical idea of the present invention. possible.

The manufacturing method of the transparent polyimide film of the present invention,

A first step of preparing an amine-terminated polyamic acid;

A second step of preparing a polyimide precursor by reacting norbornene anhydride with the amine-terminated polyamic acid; and

A third step of casting the polyimide precursor prepared in the second step on a support and imidizing it to produce a polyimide film; characterized in that it comprises,

The terminal of the polyimide precursor prepared in step 2 may include both an amine group and a carboxylic acid containing a double bond.

When the manufacturing method of the transparent polyimide film is described in detail,

The amine-terminated polyamic acid of the first step is prepared by a reaction of i) a compound having a structural unit derived from diamine and ii) a compound having a structural unit derived from an acid dianhydride.

The amount of i) diamine and ii) acid dianhydride is 0.3 to 0.9 mol of the acid dianhydride compound with respect to 1 mol of the diamine compound.

The i) diamine is oxydianiline (4,4'-Oxydianiline, ODA), p-phenylene diamine (para-phenylene diamine, pPDA), m-phenylene diamine (meta-phenylene diamine, mPDA) , p-methylene diamine (para-Methylene Diamine, pMDA), m-methylene diamine (meta-Methylene Diamine, mMDA), bis aminophenoxy benzene (1,3-bis (3-aminophenoxy) benzene, 133APB), Bisaminophenoxybenzene (1,3-bis(4-aminophenoxy) benzene, 134APB), bisaminophenoxyphenyl hexafluoropropane (2,2'-bis[4(4-aminophenoxy)phenyl]hexafluoro propane, 4BDAF ), bis-aminophenyl hexafluoropropane (2,2'-bis (3-aminophenyl)hexafluoropropane, 33-6F), bis-aminophenyl hexafluoropropane (2,2'-bis (4-aminophenyl)hexafluoropropane, 44 -6F), bis(4-aminophenyl)sulfone, 4DDS), bis(3-aminophenyl)sulfone, 3DDS), bis-trifluoromethylbenzidine (2,2'-bis ( trifluoromethyl)benzidine, TFDB), cyclohexane diamine (1,3-Cyclohexane diamine, 13CHD), cyclohexane diamine (1,4-Cyclohexane diamine, 14CHD), bisaminophenoxyphenylpropane (2,2-Bis[ 4-(4-aminophenoxy)-phenyl]propane, 6HMDA), bis-aminohydroxyphenyl hexafluoropropane (2,2-Bis(3-amino-4-hydroxy-phenyl)-hexafluoropropane, DBOH), and bis-amino At least one selected from the group consisting of phenoxy diphenyl sulfone (4,4'-Bis (3-aminophenoxy) diphenyl sulfone, DBSDA),

The ii) acid dianhydride is 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), 4- (2,5-dioxotetrahydrofuran-3-yl) - 1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA), pyromellitic acid dianhydride (1,2,4,5-benzene tetracarboxylic dianhydride, pyromellicticacid dianhydride, PMDA ), benzophenone tetracarboxylic dianhydride (3,3,4,4-Benzophenone tetracarboxylic dianhydride, BTDA), biphenyl tetracarboxylic dianhydride (3,3,4,4-Biphenyltetracarboxylic dianhydride, BPDA) , oxydiphthalic dianhydride (4,4-Oxydiphthalic dianhydride, ODPA), biscarboxyphenyl dimethylsilane dianhydride (Bis(3,4dicarboxyphenyl)dimethylsilane dianhydride, SiDA), bis dicarboxyphenoxy diphenyl sulfide dianhydride (4,4-bis(3,4-dicarboxyphenoxy) diphenyl sulfide dianhydride (BDSDA), sulfonyldiphthalic anhydride (SO2DPA), cyclobutane tetracarboxylic dianhydride (Cyclobutane-1,2, from the group consisting of 3,4-tetracarboxylic dianhydride (CBDA), and isopropylidene diphenoxy bisphthalic anhydride (4,4'-(4,4'-Isopropylidene diphenoxy)bis(phthalic anhydride), 6HBDA) It is 1 or more types selected.

The reaction between i) a compound having a structural unit derived from diamine and ii) a compound having a structural unit derived from an acid dianhydride can be prepared by a known method of polymerization in an organic polar solvent.

Specifically, after dissolving the diamine in an aprotic amide solvent such as N,N-dimethylacetamide and N-methylpyrrolidone under a nitrogen stream, the diamine solution is 0 ° C to 25 ° C, preferably Preferably, it is maintained at 5 ° C to 15 ° C or less.

It is obtained by adding acid dianhydride to the diamine solution and reacting at the above temperature for about 1 hour to 10 hours while maintaining the above temperature. Both ends of the polyamic acid obtained at this time are sealed with aromatic monoamine.

The second step is a step of preparing a polyimide precursor by reacting norbornene anhydride with the amine-terminated polyamic acid prepared in the first step.

In the reaction of the second step, norbornenic anhydride is directly added to the polyamic acid at the amine terminal of the first step without separating the polyamic acid at the amine terminal of the first step, the reaction temperature is 0 ° C to 25 ° C, preferably is reacted at 5 ° C to 15 ° C for 1 hour to 10 hours, preferably 3 hours to 10 hours.

The amount of norbornenic anhydride used is 0.1 to 2.0 moles, preferably 0.2 to 1.5 moles, based on 1 mole of the diamine.

The polyimide precursor prepared in the second step may include an amine group or/and a carboxylic acid group including a double bond at the terminal.

That is, the polyimide precursor is (a) a polyimide precursor having a carboxylic acid group including a double bond obtained by reaction with norbornene acid anhydride at both amine terminals of the polyamic acid, (b) among both amine terminals of the polyamic acid A polyimide precursor having one amine terminal having a carboxylic acid group containing a double bond obtained by reaction with norbornenic anhydride, and (c) a compound having a structural unit derived from diamine and a structural unit derived from acid dianhydride It includes the polyimide precursor of the polyamic acid of the first step by the reaction of the compound.

The third step is a step of manufacturing a polyimide film by casting the polyimide precursor prepared in the second step on a support and imidating it.

The imidization may be performed by thermal imidization or chemical imidization. In thermal imidation, the polyimide precursor of the second step is applied on an arbitrary support such as glass, metal, resin (polyimide film, etc.) using an applicator, and After drying for 180 minutes to remove the solvent, additional heat treatment is performed. The additional heat treatment is performed by heating from 100 °C to 300 °C for about 1 hour to 3 hours at a heating rate of 1 to 5 °C/min, preferably 2 to 4 °C/min in a vacuum state. ; and a secondary additional heat treatment of additional heat treatment at 250° C. to 400° C. for about 10 minutes to 1 hour. A transparent polyimide film may be obtained by the second additional heat treatment.

In chemical imidization, a dehydrating agent and a catalyst are added to a polyimide precursor (polyamic acid) solution, and chemical dehydration is performed at 30°C to 60°C. Acetic anhydride is exemplified as a typical dehydrating agent, and pyridine is exemplified as a catalyst.

In the thermal imidization, it is also possible to carry out the imidization heat treatment within a specific time depending on the combination of the type of acid dianhydride or diamine and the type of solvent. Moreover, it is also possible to use thermal imidation and chemical imidation together.

When applying the polyimide precursor to the support, it is applied as a polyimide precursor solution in which the polyimide precursor is dissolved in a known solvent, or the reaction solution is applied as it is after the reaction in the second step without separate separation after the polyimide precursor is prepared. can

In addition, as for the thickness of the said support body, the thing of about 0.02-1.0 mm can be used, for example.

The thickness of the polyimide film obtained by polyimide in the third step may vary depending on the use, and may preferably be 10 to 100 μm. Preferably it may be 10 to 50 μm.

The polyimide film produced by the polyimide manufacturing method including the first to third steps as described above exhibits excellent performance in terms of transparency, dimensional stability, heat resistance, and ease of peeling from the support.

Among the above properties, the transparency of the polyimide film of the present invention has a light transmittance of 90% or more at 550 nm, and a yellow index of 5 or less, preferably 4.5 or less. In particular, the polyimide film of the present invention has Haze is 1% or less, preferably 0.5% or less. Moreover, the coefficient of thermal expansion (CTE) is 55 ppm/°C or less, and the pencil hardness is 2H or more.

The above polyimide film of the present invention can also be easily peeled off from the support by a known method.

The polyimide film obtained by using the polyimide precursor of the present invention replaces the glass substrate, which is an existing material, in thin-type display or touch panel applications, satisfies required characteristics such as dimensional stability, and is suitable as a practical flexible heat-resistant transparent resin substrate material. can be used appropriately. That is, polyimide films are used as substrate materials, liquid crystal display devices, organic EL display devices, touch panels, and major display devices such as electronic paper, as well as components related thereto, such as thin film transistors (TFTs), color filters, and conductive films. , gas barrier films, flexible circuit boards, adhesive films, etc. can also be formed.

In this case, the polyimide film may be composed of not only a single layer but also a plurality of layers of polyimide.

In the method of forming the functional layer, formation conditions are appropriately set according to the target device, but in general, after forming a metal film, inorganic film, organic film, etc. on a polyimide film, it is necessary to It can be obtained using a known method, such as patterning (patterning) or heat treatment in a predetermined shape according to. That is, the means for forming these display elements is not particularly limited, and for example, sputtering, vapor deposition, CVD, printing, exposure, immersion, etc. are appropriately selected, and if necessary, these processes are performed in a vacuum chamber or the like It is good even if you lose. After the functional layer is formed on the polyimide film, the separation of the support and the polyimide film having the functional layer may be performed immediately after the functional layer is formed through various processes, or after a certain period of time has elapsed. It may be made integral with the support body, and may be separated and removed immediately before use as a display device, for example.

After the polyimide layer (film) formed on the support body using the polyimide precursor of this invention further forms a functional layer thereon, the polyimide film is peeled from the support body together with the functional layer. For example, after the assembly/manufacturing process of various electronic components for forming a functional layer on a polyimide film is completed, a polyimide layer (film) having a functional layer is laser-cut to the obtained polyimide film having a functional layer on a support body. It peels from the support body by light irradiation. As described above, when the interface between the support (glass) and the polyimide film is irradiated using an excimer laser (wavelength: 308 nm), the polyimide film having a functional layer can be easily separated from the support.

Below, the present invention will be specifically described based on Examples and Comparative Examples. In addition, this invention is not limited to these Examples.

The measurement method and evaluation method of each physical property in Examples etc. are shown below.

<Light Transmittance and Yellowness (YI)>

The light transmittance (T550) at 550 nm of the polyimide film (50 mm × 50 mm, thickness 40 μm) was determined with a UV-3600 spectrophotometer manufactured by SHIMADZU CORPORATION.

In addition, YI (yellowness) was calculated based on the following formula.

YI＝100×(1.2879X-1.0592Z)／Y

X, Y, Z are the tristimulus values of the test piece and are specified in JIS Z 8722.

<Coefficient of Thermal Expansion (CTE)>

A polyimide film having a size of 3 mm × 15 mm was heated from 30 ° C. to 280 ° C. at a constant heating rate (10 ° C./min) while applying a load of 5.0 g with a thermomechanical analysis (TMA) device, and then at 250 ° C. The temperature was decreased to 100° C., and the thermal expansion coefficient was measured from the amount of elongation (linear expansion) of the polyimide film at the time of the temperature decrease.

<Glass transition temperature (Tg)>

The dynamic viscoelasticity of a polyimide film (5 mm × 70 mm) when the temperature was raised from 23 ° C to 500 ° C at 5 ° C / min was measured with a dynamic thermomechanical analyzer, and the glass transition temperature (tan δ maximum value: ° C) was obtained. .

<Modulus(Gpa)>

The center of the film surface was measured for modulus (compressive modulus) by the nanoindentation method using a picodenter HM-500 (Fisher Instruments, Inc.). The measurement was performed at a temperature of 25° C. and a humidity of 50%, and the average value was derived after measuring 5 times for each film.

<Haze(%)>

Haze was measured using a spectrophotometer (HZ-1, Suga, Japan).

<Pencil Hardness>

Pencil hardness was measured using a pencil hardness tester (PHT, Korea Seokbo Scientific Co., Ltd.) under a load of 750 g. A pencil made by Mitsubishi was used, and the test was performed 5 times per pencil hardness. When the scratches were 2 or more times, it was determined as defective.

- Evaluation standard -

0 scratches: Pass, 1 scratch: Pass, 2 or more scratches: Bad

<Example 1>

After filling 769g of N-methylpinolidone (NMP) while passing nitrogen into a 2L reactor equipped with an agitator, nitrogen injector, dropping funnel, temperature controller and cooler, adjust the temperature of the reactor to 10 ℃, and then TFDB (2,2 64.05 g (0.20 mol) of '-bis(trifluoromethyl) benzidine) was dissolved and the solution was maintained at 10°C. Here, 35.54 g (0.08 mol) of 6FDA (2,2-bis (3,4-dicarboxyphenyl) hexafluoro-propane dianhydride) was added and stirred for 2 hours to dissolve and react. Through the above reaction, a polyamic acid represented by the following reaction formula was prepared.

Thereafter, without separating the polyamic acid, 24.62 g (0.15 mol) of NBA (norbornenic acid anhydride) was immediately added and the reaction proceeded for 5 hours while maintaining at 10 ° C. NBA in the reaction mixture of the polyamic acid and NBA using IR It is confirmed that is no longer detected, the reaction is terminated, and a polyimide precursor represented by the following reaction formula is obtained.

The obtained polyimide precursor solution was cast on a stainless plate in a thickness of 400 μm and dried with hot air at 150° C. for 30 minutes to remove the solvent. Then, the dried film was peeled from the stainless plate and the film was fixed to the frame with pins. Thereafter, the frame fixed with the film was placed in a vacuum oven and heated from 100 ° C to 300 ° C at a heating rate of 2.5 ° C / min for 2 hours to obtain a polyimide film, which was additionally heat-treated at 300 ° C for 30 minutes to obtain a A transparent polyimide film was prepared.

<Example 2>

A polyimide film was prepared in the same manner as in Example 1, except that 0.2 mol of TFDB, 0.1 mol of 6FDA, and 0.1 mol of NBA were added.

<Example 3>

A polyimide film was prepared in the same manner as in Example 1 except for adding 0.24 mol of NBA.

<Example 4>

A polyimide film was prepared in the same manner as in Example 1, except that 0.2 mol of TFDB, 0.07 mol of 6FDA, and 0.15 mol of NBA were added.

<Comparative Example 1>

A polyimide film was prepared in the same manner as in Example 1 except that 0.2 mol of TFDB, 0.1 mol of 6FDA, and NBA were not added.

<Comparative Example 2>

A polyimide film was prepared in the same manner as in Example 1, except that 0.19 mol of TFDB, 0.2 mol of 6FDA, and 0.01 mol of NBA were added.

The evaluation results of the characteristics of the polyimide films of Examples 1 to 4 and Comparative Examples 1 to 2 are shown in Table 1 below.

glass transition temperature
(℃) pencil hardness 550 nm
Permeability (%) Haze
(%) CTE
(ppm/℃) Yellow
Index Modulus
(Gpa) Example 1 318 2H 90.1 0.3 49 4.1 3.8 Example 2 305 2H 91.0 0.3 53 4.2 3.6 Example 3 312 2H 90.4 0.4 52 4.3 3.0 Example 4 298 2H 90.2 0.4 54 4.4 2.9 Comparative Example 1 270 HB 88.9 2.1 60 5.8 1.1 Comparative Example 2 300 H 88.6 1.2 65 6.8 0.9

As shown in Table 1, the polyimide precursors obtained by reacting polyamic acid with norbornene acid anhydride in Examples 1 to 4 of the present invention have high glass transition temperatures and excellent pencil hardness. In particular, not only does the transmittance at 550 nm exceed 90%, but it also exhibits a haze of less than 0.5 and a yellow index of less than 4.5, so transparency is excellent when used in electronic devices, and the mechanical properties are excellent with a modulus of 2.9 or more. great.

Therefore, the polyimide film produced by the polyimide film manufacturing method of the present invention exhibiting excellent properties as described above can replace the glass substrate in the use of a display or touch panel, and is a practical product that satisfies required properties such as dimensional stability. It has the advantage of being suitable for use as a flexible heat-resistant transparent resin substrate material.

Claims (16)

It relates to a polyimide precursor having a fluorine group containing a double bond compound produced by reacting norbornenic acid anhydride with an amine-terminated polyamic acid produced by the reaction of a diamine compound having a fluorine group and this anhydride compound in an organic solvent,
A polyimide precursor having a fluorine group, characterized in that the polyimide film having a fluorine group obtained by imidizing the polyimide precursor having a fluorine group has a transmittance of 90% or more and a yellow index of 4.5 or less when measured at 550 nm. . According to claim 1,
A polyimide precursor having a fluorine group, characterized in that it is prepared from 0.3 to 0.9 mol of the dianhydride compound and 0.1 to 2.0 mol of the norbornenic acid anhydride with respect to 1 mol of the diamine compound having a fluorine group. According to claim 1,
The diamine compound having a fluorine group is bis amino phenoxy phenyl hexafluoropropane (2,2'-bis [4 (4-aminophenoxy) phenyl] hexafluoropropane, 4BDAF), bis aminophenyl hexafluoro propane (2,2' -bis(3-aminophenyl)hexafluoropropane, 33-6F), bis-aminophenylhexafluoropropane (2,2'-bis(4-aminophenyl) hexafluoropropane, 44-6F), bis-trifluoromethylbenzidine (2,2 At least one selected from the group consisting of '-bis (trifluoromethyl) benzidine, TFDB), and bis-aminohydroxyphenyl hexafluoropropane (2,2-Bis (3-amino-4-hydroxyphenyl) hexafluoro propane, DBOH) Characterized in that, a polyimide precursor having a fluorine group. According to claim 1,
This anhydride compound is 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), 4- (2,5-dioxotetrahydrofuran-3-yl) -1, 2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA), 1,2,4,5-benzene tetracarboxylic dianhydride, pyromellitic acid dianhydride (PMDA), benzo 3,3,4,4-Benzophenone tetracarboxylic dianhydride (BTDA), 3,3,4,4-Biphenyl tetracarboxylic dianhydride (BPDA), oxy Diphthalic dianhydride (4,4-Oxydiphthalic dianhydride, ODPA), biscarboxyphenyl dimethyl silane dianhydride (Bis(3,4dicarboxyphenyl) dimethylsilane dianhydride, SiDA), bis dicarboxyphenoxy diphenyl sulfide dianhydride (4 ,4-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride (BDSDA), sulfonyldiphthalic anhydride (SO2DPA), cyclobutane tetracarboxylic dianhydride (Cyclobutane-1,2,3, 4-tetracarboxylic dianhydride, CBDA), and isopropylidene diphenoxy bis phthalic anhydride (4,4'-(4,4'-Isopropylidene diphenoxy) bis (phthalic anhydride), selected from the group consisting of 6HBDA) A polyimide precursor having at least one fluorine group, characterized in that it is one or more. A first step of preparing an amine-terminated polyamic acid by reacting a diamine compound having a fluorine group with this anhydride compound in an organic solvent;
A second step of preparing a polyimide precursor having a fluorine group by reacting norbornene anhydride with the amine-terminated polyamic acid; and
A third step of preparing a polyimide film having a fluorine group by casting the polyimide precursor having a fluorine group prepared in the second step on a support and imidating it;
A method for producing a polyimide film having a fluorine group, wherein the terminal of the polyimide precursor having a fluorine group prepared in step 2 includes both an amine group and a carboxylic acid containing a double bond,
Method for producing a polyimide film having a fluorine group, characterized in that the transmittance measured at 550 nm of the polyimide film having a fluorine group is 90% or more and the yellow index is 4.5 or less. According to claim 5,
The amounts of the diamine compound having a fluorine group, the dianhydride compound, and norbornenic acid anhydride in the first and second steps are 0.3 to 0.9 mol of the dianhydride compound, and A method for producing a polyimide film having a fluorine group, characterized in that the norbornene acid anhydride is 0.1 to 2.0 mol. According to claim 5,
The diamine compound is bisamino phenoxy phenyl hexafluoropropane (2,2'-bis [4 (4-aminophenoxy) phenyl] hexafluoropropane, 4BDAF), bis aminophenyl hexafluoro propane (2,2'-bis ( 3-aminophenyl)hexafluoropropane, 33-6F), bis aminophenyl hexafluoropropane (2,2'-bis(4-aminophenyl) hexafluoropropane, 44-6F), bis trifluoromethyl benzidine (2,2'-bis (trifluoromethyl) benzidine, TFDB), and bis-aminohydroxyphenyl hexafluoropropane (2,2-Bis (3-amino-4-hydroxyphenyl) -hexafluoropropane, DBOH) characterized in that at least one selected from the group consisting of Method for producing a polyimide film having a fluorine group. According to claim 5,
This anhydride compound is 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA), 4- (2,5-dioxotetrahydrofuran-3-yl) -1, 2,3,4-tetrahydronaphthalene-1,2-dicarboxylic anhydride (TDA), 1,2,4,5-benzene tetracarboxylic dianhydride, pyromellitic acid dianhydride (PMDA), benzo 3,3,4,4-Benzophenone tetracarboxylic dianhydride (BTDA), 3,3,4,4-Biphenyl tetracarboxylic dianhydride (BPDA), oxy Diphthalic dianhydride (4,4-Oxydiphthalic dianhydride, ODPA), biscarboxyphenyl dimethyl silane dianhydride (Bis(3,4dicarboxyphenyl)dimethylsilane dianhydride, SiDA), bis dicarboxyphenoxy diphenyl sulfide dianhydride (4 ,4-bis (3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride (BDSDA), sulfonyldiphthalic anhydride (SO2DPA), cyclobutane tetracarboxylic dianhydride (Cyclobutane-1,2,3, 4-tetracarboxylic dianhydride, CBDA), and isopropylidene diphenoxy bis phthalic anhydride (4,4'-(4,4'-Isopropylidene diphenoxy) bis (phthalic anhydride), selected from the group consisting of 6HBDA) A method for producing a polyimide film having a fluorine group, characterized in that at least one type. According to claim 5,
The method for producing a polyimide film having a fluorine group, characterized in that the polyimide film has a thickness of 10 to 50 μm. According to claim 9,
Characterized in that the coefficient of linear thermal expansion (CTE) of the polyimide film is 55 ppm / ℃ or less, having a fluorine group Manufacturing method of polyimide film. delete According to claim 5,
The first step and the second step reaction is characterized in that each is carried out at 0 ℃ to 25 ℃ for 1 to 10 hours, having a fluorine group Manufacturing method of polyimide film. According to claim 5,
In the third step, the heat treatment is performed at a temperature of 80 ° C to 300 ° C for 60 minutes to 180 minutes to remove the solvent, and then to 1 hour to 3 hours from 100 ° C to 300 ° C at a heating rate of 1 to 5 ° C / min in a vacuum state. 1st additional heat treatment with time heating; and a secondary additional heat treatment of additional heat treatment at 250° C. to 400° C. for 10 minutes to 1 hour. An optical film comprising a hard coating layer on one side or both sides of a polyimide film prepared by the method of manufacturing a polyimide film according to any one of claims 5 to 10, 12, and 13. An image display device having the optical film of claim 14.







According to claim 1,
A polyimide precursor having a fluorine group, characterized in that the polyimide film having a fluorine group has a coefficient of linear thermal expansion (CTE) of 55 ppm / ° C or less in a thickness of 10 to 50 μm.