WO2018216853A1 - Method for manufacturing polyamic acid resin having easy laser separation property and high heat resistance and polyimide film manufactured using same - Google Patents

Abstract

The present invention relates to a method for manufacturing a polyamic acid resin having easy laser separation property and high heat resistance, and a polyimide film manufactured using a polyamid resin manufactured thereby, and particularly, for manufacturing a polyamic acid resin enabling laser separation at low energy to allow separation without causing damage (curling, defects, breaking, etc.) to the film while maintaining an appropriate level of adhesive force to glass and the like. The polyimide film manufactured by using the polyamic acid resin can be useful in a flexible display substrate material and a semiconductor material among others.

Description

Method for preparing polyamic acid resin having ease of laser peeling and high heat resistance and polyimide film prepared using the same

The present invention relates to a method for preparing a polyamic acid resin having easy laser peeling and high heat resistance, and a polyimide film prepared by using the polyamide resin prepared by the present invention. Laser peeling is possible at low energy to produce a polyamic acid resin that can be peeled off without damage to the thin film (curl, defect, breakage, etc.) and has high heat resistance. It may be usefully used for a flexible display substrate material and a semiconductor material.

Flexible polymer materials are attracting attention as substrate materials of flexible displays, which are being spotlighted as next generation display devices.

The flexible device generally uses an organic light emitting diode (OLED) display, and a TFT process with a high process temperature (300 to 500 ° C) is used. Polymer materials that withstand such high process temperatures are extremely limited, and polyimide (PI) resin, which is a polymer having excellent heat resistance, is mainly used.

An organic light emitting diode (OLED) display manufactures a display by coating a resin on a glass substrate, thermosetting and filming the film, and removing the glass substrate from the glass substrate after several steps.

The viscosity of the resin in the process of applying the resin to the glass substrate during the manufacturing process is a very important factor in the film production. If the viscosity is too high, it is not easy to remove the solvent of the resin during the heat treatment, thereby deteriorating the properties of the thin film, or difficult to apply uniformly during coating, resulting in poor uniformity of the thin film, which causes product defects in OLED panel manufacturing. On the other hand, if the viscosity is too low, it is difficult to coat the thickness required for coating, and likewise, it is difficult to control the uniformity of the thin film.

Therefore, it can be said that resin having an appropriate viscosity is advantageous in thin film production. In addition, product defects may occur due to thermal shock caused by high process temperatures (> 350 ° C.) during the TFT process.

Therefore, it is necessary to have a coefficient of thermal expansion of the glass substrate level to minimize product defects. Also, in general, the thin film is peeled off from the glass substrate by the laser peeling method after the thin film is manufactured. As a non-polar molecule, the adhesive property with the glass is high after heat treatment due to the characteristics of the resin. ), Product damage, etc. occurs. When the laser is peeled off, peeling is not easy, and if the energy is irradiated with high energy, the film is damaged.

On the other hand, Korean Patent Laid-Open Publication No. 1998-015679 relates to a method for producing an aromatic polyimide film, wherein an excessive amount of acid dianhydride is added to the aromatic diamine several times and polymerized at a temperature of about 5 to 20 ° C. using an organic polar solvent. The polyimide film is made of the polyamic acid resin obtained from the resin, and thus the physical properties such as heat resistance are excellent, but the polyamic acid viscosity at room temperature is lowered while maintaining the physical properties. There is a limit in that an additional process for lowering the required amount is required.

Therefore, when the laser is peeled off easily, the above problems do not occur. It is possible to peel without damaging the thin film when laser peeling is performed at low energy.

Accordingly, there is a need to develop a polyamic acid resin having low viscosity, controlling adhesion to glass and an appropriate level, and capable of laser peeling at low energy, and having high heat resistance and low thermal expansion coefficient.

In order to solve the above problems, the present inventors have optimized and controlled the dosing method, the split dosing time, and the polymerization temperature conditions of the composition used in the production of polyamide resin, in order to develop a polyamic acid resin having high heat resistance and easy laser peeling. By this, it was found that the molar ratio of the composition used in excess can be minimized and the viscosity can be easily adjusted, and the superior physical property properties are minimized because the molar ratio of the composition used is minimized compared to the existing method based on the equivalent level of viscosity. It has been found that the polyamic acid resin having the present invention can be prepared to complete the present invention. In addition, it has been found that by optimizing such a split dosing method, a dosing time and a polymerization temperature, a polyamic acid resin having a low viscosity can be obtained without deteriorating physical properties.

Accordingly, an object of the present invention is to provide a method for producing a polyamic acid resin having easy laser peeling and high heat resistance.

In addition, the present invention is a film prepared by heat-treating the polyamic acid resin obtained by the above method, the adhesive strength of 0.2 ~ 2.0 N / cm, peeling energy 200mJ / cm ² based on the film thickness 10 ~ 15 ㎛ Hereinafter, the object is to provide a polyimide resin film characterized in that the thermal expansion coefficient in the range of 100 ~ 350 ℃ is 10 ppm / ℃ or less.

The present invention is a method for producing a polyamic acid resin prepared by polymerizing a composition comprising a diamine monomer, an acid dianhydride compound, and an organic solvent, wherein the polyamic acid resin is an acid dianhydride after dissolving the diamine monomer in an organic solvent. The compound is polymerized by four times or more dividedly injected, but the addition time is 30 to 60 minutes intervals are provided to provide a method for producing a polyamic acid resin having easy laser peeling and high heat resistance characterized in that the input.

In another aspect, the present invention is a film prepared by heat-treating the polyamic acid resin prepared by the above method, the adhesive strength of 0.2 ~ 2.0 N / cm, peeling energy 200 mJ / cm ² based on the film thickness 10 ~ 15 ㎛ Hereinafter, the polyimide resin film which has a thermal expansion coefficient of 10 ppm / degrees C or less in 100-350 degreeC range is provided.

The polyimide resin prepared by the manufacturing method according to the present invention has a low viscosity and exhibits excellent laser peel force at low energy when producing a polyimide film through heat curing, and has excellent mechanical and heat resistance characteristics, thereby providing a flexible display substrate. It can be usefully used for materials, semiconductor materials and the like.

Figure 1 shows the change in viscosity according to the split input conditions when producing a polyamic acid resin according to the present invention.

Figure 2 is a result of testing the peeling of the film after irradiating a laser with a different energy size for the polyamide film prepared by applying a polyamic acid resin according to the present invention on a glass substrate and heat treatment (photo).

Hereinafter, the present invention will be described in more detail as one embodiment.

The present invention provides a method for producing a polyamic acid resin prepared by polymerizing a composition comprising a diamine monomer, an acid dianhydride compound, and an organic solvent. In order to produce a polyimide film having a low viscosity and having appropriate laser peeling properties, excellent heat resistance, and a low coefficient of thermal expansion during film production, a polyamide resin prepared by a predetermined method is used.

Specifically, the polyamic acid resin production method according to the present invention is polymerized by dissolving the diamine monomer in an organic solvent and then divided into four or more acid dianhydride compounds, the input time is put at intervals of 30 to 60 minutes Manufacture. Figure 1 shows the change in viscosity according to the split input conditions when producing a polyamic acid resin according to the present invention.

In general, in adjusting the viscosity of the polyamic acid resin, it is preferable to add an excess of a molar ratio of the dianhydride monomer and the diamine monomer so that either side is -5 to 5 mol% to reach the target viscosity. This is for reasons of ensuring control and storage stability. However, if the molar ratio is excessively excessive on either side, it causes various properties during polyimide film production.

In order to solve the above problems, the preparation of the polyamic acid resin of the present invention by optimizing the number of times, the addition time and the polymerization temperature of the monomer, by minimizing the excess of the molar ratio of the composition to be used and adjusting the viscosity, on the basis of equivalent viscosity In comparison with the conventional method, since it minimizes the molar ratio, it is possible to manufacture a polyamic acid resin having more excellent properties. In addition, a polyamic acid resin having a low viscosity can be obtained without deteriorating physical properties.

In more detail, during the polymerization of the polyamide resin, it is preferable to dissolve the diamine monomer in an organic solvent and divide the dianhydride monomer four times or more. More preferably, it is 4-6 times. Even more preferably 5 times. At this time, the polymerization temperature is preferably 40 ~ 60 ℃. More preferably, it is 40 degreeC.

When based on 100 mol% dianhydride-based monomer, it is preferable to add a 4 to 6 equally divided at a time difference of 30 to 60 minutes. After 4 to 6 times, the amount of the dianhydride-based monomer is adjusted according to the target viscosity of the polyamic acid solution. This split-injection method enables the growth of molecular chains in the form of oligomers at an appropriate molecular weight level, not high molecular weight, to achieve viscosity in solution, and heat-treat oligomer-type molecules in high molecular weight during imidization during polyimide film production by heat treatment. Combination is possible.

Accordingly, the polyamic acid resin of the present invention may exhibit excellent mechanical properties, high heat resistance, and low coefficient of thermal expansion when manufactured into a film while having a low viscosity. This can be confirmed through an experimental example to be described later. In addition, in preparing the polyamic acid resin according to the present invention, the composition used is as follows.

(A) Diamine compound

In producing the polyamic acid resin of the present invention, the diamine monomers which are the basic components include fluorinated aromatic diamines and non-fluorinated diamines. When the polyamic acid resin contains a fluorinated aromatic diamine in which a fluorine substituent is introduced, the fluorine substituent increases the surface tension and lowers the adhesion to the glass substrate. Thus, the curl, product defect, Problems such as product breakage can be improved, and excellent laser stripping characteristics can be exhibited at low energy. In addition, when a mixture of such fluorinated aromatic diamine and non-fluorinated aromatic diamine is used, excellent heat resistance and low coefficient of thermal expansion are achieved due to the rigidity of the aromatic structure of the non-fluorinated aromatic diamine, while giving peeling characteristics due to the fluorine substituent of the fluorinated aromatic diamine. To provide a polyimide film having at the same time, it is possible to minimize the damage of the film during laser peeling.

The fluorinated aromatic diamine used in the present invention is not particularly limited as long as it is an aromatic diamine containing fluorine. For example, 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl (2,2'-Bis (trifluoromethyl) -4,4'-Diaminobiphenyl, TFMB), bis aminohydride Bisaminohydroxyphebyl hexafluoropropane (DBOH), bis aminophenoxy phenyl hexafluoropropane (4BDAF), 2,2'-bis (trifluoromethyl) -4,3'-dia Minobiphenyl (2,2'-Bis (trifluoromethyl) -4,3'-Diaminobiphenyl), 2,2'-bis (trifluoromethyl) -5,5'-diaminobiphenyl (2,2'- Bis (trifluoromethyl) -5,5'-Diaminobiphenyl), but is not limited thereto. These may be used alone or in combination of two or more thereof. Among these, when TFMB is used, since peeling characteristic and heat resistance characteristic can be improved simultaneously, it is preferable.

Although the content of such fluorinated aromatic diamine is not particularly limited, when the total diamine-based compound is 5 to 50 mol%, preferably 5 to 30 mol% based on 100 mol%, the peeling property can be expressed while maintaining the heat resistance. Can be.

The polyamic acid resin of the present invention may further include a non-fluorinated aromatic diamine as the aromatic diamine component. Examples are para-phenylenediamine (PPD), meta-phenylene diamine (MPD), 4,4'-oxydianiline (ODA), bis amino phenoxy phenylpropane (6HMDA), 4,4'-diaminodi Phenyl sulfone (4,4'-DDS), 9,9'-bis (4-aminophenyl) fluorene (FDA), para-xylylenediamine (p-XDA), meta-xylylenediamine (m-XDA) , 4,4'-methylene dianiline (MDA), 4,4'-diaminobenzoate (4,4'-DABA), 4,4'-bis (4-aminophenoxy) biphenyl (4.4'- BAPP), and these may be used alone or in combination of two or more thereof. Among them, PPD is preferred because it can exhibit excellent heat resistance characteristics and low thermal expansion coefficient characteristics.

The content of such non-fluorinated aromatic diamine is not particularly limited, but may be about 50 to 95 mol%, preferably 70 to 95 mol% based on 100 mol% of the diamine-based compound.

(B) acid dianhydride compounds

The polyamic acid resin of this invention contains an aromatic acid dianhydride compound as an acid dianhydride component.

In the polyamic acid resin, when the aromatic acid dianhydride compound is used, the polyimide heat resistance property and the low coefficient of thermal expansion can be improved. Due to the rigid molecular structure of the aromatic acid dianhydride, it is possible to produce a polyimide film having excellent heat resistance. The aromatic acid dianhydride is not particularly limited. For example, 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), 4,4'-(4,4'-hexafluoroisopropylidenediphenoxy) bis- (phthalic anhydride ) (6-FDPDA), pyromellitic dianhydride (PMDA), 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 3,3', 4,4'-benzophenone Tetracarboxylic dianhydride (BTDA), 4,4'oxydiphthalic anhydride (ODPA), 2,2-bis [4-3,4-dicarboxyphenoxy] phenyl] propane anhydride (BPADA), 3, 3 ', 4, 4'- diphenyl sulfone tetra carboxylic anhydride (DSDA), ethylene glycol bis (4- trimellitate anhydride) (TMEG) and the like, but is not limited thereto. These may be used alone or in combination of two or more thereof. Among these, it is preferable to use PMDA or BPDA as aromatic acid dianhydride.

Although the content of the aromatic acid dianhydride described above is not particularly limited, when the BPDA is 50 to 90 mol%, preferably 70 to 100 mol%, based on 100 mol% of the total acid dianhydride, PMDA 10 to 50 mol%, preferably 0 To 30 mol% may exhibit excellent heat resistance.

(C) organic solvent

As a solvent used for polyamic-acid resin manufacture of this invention, if a polyamic-acid resin melt | dissolves, there will be no problem, and the structure in particular is not limited. For example, m-cresol, N-methyl-2-pyrrolidone (NMP), N-ethyl-2-pyrrolidone (NEP), N, N-dimethylformamide (DMF), N, N-di Ethylformamide (DEF), N, N-dimethylacetamide (DMAc), N, N-diethylacetamide (DEAc), dimethylsulfoxide (DMSO), diethylacetate (DEA), 3-methoxy-N Preference is given to using polar solvents such as, N-dimethyl propanamide (DMPA), low boiling solvents such as tetrahydrofuran (THF), chloroform and the like or low absorbing solvents such as gamma-butyrolactone and GBL. These may be used alone or in combination of two or more thereof.

(D) reaction catalyst

The polyamic acid resin of the present invention may further include one or more reaction catalysts from the group consisting of trimethylamine, xylene, pyridine, and quinoline, depending on the reactivity. It is not limited. In addition, the polyamic acid resin may contain a small amount of one or more additives selected from the group consisting of plasticizers, antioxidants, flame retardants, dispersants, viscosity modifiers, and leveling agents, if necessary, within a range that does not significantly impair the objects and effects of the present invention. It may include.

In the polyamic acid resin of the present invention described above, the content of aromatic diamine (B), aromatic acid dianhydride (C), organic solvent (D), and catalyst (E) is not particularly limited. The total amount of an acid dianhydride component and a diamine component is 5 mass% or more, Preferably it is 10 mass% or more with respect to the total amount of a solvent, an acid dianhydride component, and a diamine component containing the polyamic-acid resin and a solvent of this invention. Preferably it is the ratio of 15 mass% or more. In addition, it is preferable that it is 60 mass% or less normally, Preferably it is 50 mass% or less. If the concentration is too low, it becomes difficult to control the film thickness of the film obtained when the film is produced. If the concentration is too high, it is within the above range because there is a limit in controlling the viscosity of the polyamic acid resin.

At this time, the reaction is preferably performed for 8 to 24 hours at 10 ~ 70 ℃ temperature conditions by mixing the diamine monomer 95 ~ 100 mol% and dianhydride monomer 100 ~ 105 mol% under the organic solvent conditions. Here, the dianhydride-based monomer is preferably added in an excess of -5 to 5 mol% relative to the diamine-based monomer to reach the target viscosity, for reasons of proper viscosity control and storage stability. In addition, when the reaction time is less than 4 hours, there is a limit in terms of storage stability of the polyamic acid resin, and in the case of more than 24 hours, there is a limit in terms of productivity.

The polyamic acid resin produced through this reaction preferably has a viscosity in the range of 1,000 to 7,000 cP. If the viscosity is less than 1,000 cP, there is a problem in obtaining an appropriate level of film thickness, and if it is more than 7,000 cP, there is a problem in uniform coating and effective solvent removal, so it is preferable to be within the above range.

In addition, the production method of the polyimide film in the present invention is as follows. The present invention provides a polyimide film prepared by thermal imidating the polyamic acid resin described above. The polyamic acid resin according to the present invention is viscous, and is prepared by coating and heat-treating the glass substrate in a suitable manner during film production. The coating method may be used without limitation to known conventional methods, for example, spin coating (dip coating), dip coating (Dip coating), solvent casting (Solvent casting), slot die coating, spray coating (Spray coating) ), But is not limited thereto.

The polyamic acid resin of the present invention may be prepared into a polyimide film by heat treatment in a high temperature convection oven. At this time, the heat treatment is carried out under a nitrogen atmosphere, it is carried out for 60 to 300 minutes at 100 ~ 500 ℃ conditions. More preferably, the film is obtained under temperature and time conditions of 100 ° C./30 min, 150 ° C./10 min, 300 ° C./15 mim, and 500 ° C./10 min. This is because of the imidization which can maximize the removal of the proper solvent and properties.

Since the transparent polyimide film of the present invention is produced using the polyamic acid resin, it exhibits high transparency and has a low coefficient of thermal expansion.

The polyimide film of the present invention has a film thickness of 10 to 15 μm, an adhesive force of 0.2 to 2.0 N / cm, and a peeling energy of 200 mJ / cm ^2. Hereinafter, the coefficient of thermal expansion in the range of 100 to 350 ° C is 10 ppm / ° C or less. Preferably lower than 5 ppm / ° C. The polyimide film of the present invention can suppress defects of elements on a substrate due to curl, expansion, and shrinkage during laser peeling on a glass substrate.

Figure 2 is a result of testing the peeling of the film after irradiating a laser with a different energy size for the polyamide film prepared by applying a polyamic acid resin according to the present invention on a glass substrate and heat treatment (photo). But even when a laser beam of low-energy (160 mJ / cm ²⁾ well polyimide separation, the higher the laser of an energy irradiation (220mJ / cm ²⁾ The polyimide film of the above organic substrate is showing a phenomenon of damage have.

The polyimide film of the present invention can be used in various fields, and is flexible such as OLED display, liquid crystal display, TFT substrate, flexible printed circuit board, flexible OLED surface lighting substrate, and substrate material for electronic paper. ) May be provided as a display substrate and a protective film.

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

<Partition injection method>

Comparative Example 1

As a composition shown in Table 1 below, 19.154 g (0.177 mole) of diamine monomer and 2.987 g (0.009 mole) of TFMB were dissolved in 455.04 g of NMP, an organic solvent, and dissolved in a nitrogen atmosphere at room temperature for 30 minutes to 1 hour. Thereafter, 58.160 g (0.197 mole) of BPDA, a dianhydride-based monomer, was added thereto, followed by stirring for 6 hours to prepare a polyamic acid. (Reaction temperature: 23 DEG C, at which time the solid content was maintained to be 15% by weight relative to the total weight of the reaction solvent.) The viscosity was 5,900 cP as measured by a viscometer (Brookfield DV2T, SC4-27).

Comparative Examples 2 and 3

A polyamic acid resin was prepared in the same manner as in Comparative Example 1, except that the number of acid dianhydrides (Table 2 to 3), the addition time (30 minutes), and the excess molar ratio of diamine were used.

Examples 1 to 3

A polyamic acid resin was prepared in the same manner as in Comparative Example 1, except that the number of times of the acid dianhydride (4 to 6 times), the addition time (30 minutes), and the excess molar ratio of the diamine was used.

Experimental Example 1: Measurement of Physical Properties

The polyamic acid resins of Comparative Examples and Examples were coated on a glass plate using a bar coater, and then heat-treated in a high temperature convection oven. The heat treatment conditions were carried out in a nitrogen atmosphere, and the final film was obtained at temperature and time conditions of 100 ° C / 30min, 150 ° C / 10min, 300 ° C / 15min, and 500 ° C / 10min. The film thus obtained was measured in the physical properties as shown below and the results are shown in Table 1 below.

(a) viscosity measurement

Measurement was made using a Brookfield viscometer (Brookfield DV2T, SC4-27).

(b) Peel test

After the polyamic acid resin was heat treated to a 100mm * 100mm glass substrate, the film was cut into 25mm width, and then subjected to a 90 ° peel test at a speed of 300 mm / min using Instron's UTM.

(c) thermal properties

The coefficient of thermal expansion (CTE) of the film was measured using TMA 402 F3 from Netzsch. Force in the tension mode was set to 0.05 N, and the measured temperature was elevated to 500 ° C. at a rate of 5 / min at 30 ° C., and the coefficient of thermal expansion was measured as an average value in the range of 100 to 350 ° C.

Pyrolysis temperature (T _d , 1%) was measured using TG 209 F3 from Netzsch. Temperature measured from 30 ℃ to 120 ℃ and maintained for 10 minutes → Heated to 220 ℃ and maintained for 1 hour → 460 ℃ for 3 hours → Temperature increased to 700 ℃ (10 ℃ / min), weight loss after 460 ℃ for 3 hours Was measured.

(d) mechanical properties

Instron's UTM was used to measure the mechanical properties of the film. The film specimen was measured while pulling the specimen at a speed of 50 mm / min with a width of 10 mm and a gap between the grips set to 100 mm.

division Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 3 Polymerization conditions Acid dianhydride (unit: mol%) BPDA = 100 Diamine (Unit: mol%) PPD: TFMB = 95: 5 menstruum NMP Polymerization temperature 23 ℃ Number of acid dianhydride splits 5 One 2 3 4 6 Acid dianhydride excess (%) 3.5 6.0 4.5 4.0 3.6 3.4 Property measurement Viscosity (23 ° C, cP) 5,500 5,900 5,400 5,600 5,300 5,400 460 ° C, 3hr, Td (%) 1.89 3.25 2.67 2.31 1.94 1.92 CTE (100 ~ 300 ℃ / ppm / ℃) 7.1 13.1 11.7 8.3 7.3 7.0 Tensile strength (MPa) 255 200 220 228 250 261 Elongation (%) 15 8 11 12 14 15 * BPDA: 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (3,3', 4,4'-Biphenyltetracarboxylic dianhydride) * TFMB: 2,2'-bis (trifluoromethyl ) -Benzidine (2,2'-bis (trifluoromethyl) benzidine) * PPD: p-Phenylene diamine * NMP: N-methyl-2-pyrrolidone

As shown in Table 1, in Example 2 in which the acid dianhydride was equally divided into five portions of the composition having the same level of viscosity, the heat resistance characteristics, Td (%) and CTE acid dianhydride after holding for 3 hours at 460 ° C It was found to be superior to Comparative Examples 1 to 3 in which water was added 1 to 3 times and equally divided, and to Examples 1 and 3, which were equally divided into 4 times and 6 times.

It can be seen that the acid dianhydride is introduced in a different way to minimize the excess molar ratio of acid dianhydride to diamine, which has the same level of viscosity but excellent results in terms of heat resistance and mechanical properties.

Through the above results, the number of divided inputs of acid dianhydride according to the present invention is appropriate 4 to 6 times, preferably divided into five times.

<Split injection time>

Comparative Example 4

As a composition shown in Table 2 below, 19.154 g (0.177 mole) of diamine monomer and 2.987 g (0.009 mole) of TFMB were dissolved in 455.04 g of NMP, an organic solvent, and dissolved in a nitrogen atmosphere at room temperature for 30 minutes to 1 hour. Subsequently, 58.160 g (0.197 mole) of BPDA, an dianhydride-based monomer, was divided into five equal parts. At this time, the time between the split input was added while maintaining 10 minutes, and stirred for 6 hours to prepare a polyamic acid resin. (Reaction temperature: 23 DEG C, at which time the solid content is maintained to be 15% by weight relative to the total weight of the reaction solvent.) The monomer was not dissolved properly due to the short time between the split inputs.

Comparative Example 5

A polyamic acid resin was prepared in the same manner as in Comparative Example 4, except for the time between the divided additions of the acid dianhydride of Table 2 (20 minutes). Again, the monomers did not dissolve properly due to the short time between split inputs.

Example 2-1 to 2-4

A polyamic acid resin was prepared in the same manner as in Comparative Example 4 except for the time between the split additions of the acid dianhydride of Table 2 below.

Experimental Example 2: Measurement of Physical Properties

A polyimide film was prepared in the same manner as in Experimental Example 1, physical properties were measured, and the results are shown in Table 2 below.

Optimize time between split inputs division Comparative Example 4 Comparative Example 5 Example 2-1 Example 2-2 Example 2-3 Example 2-4 Polymerization conditions Acid dianhydride (unit: mol%) BPDA = 100 Diamine (Unit: mol%) PPD: TFMB = 95: 5 menstruum NMP Polymerization temperature 23 ℃ Number of acid dianhydride splits 5 Acid dianhydride excess (%) 3.5 Time between split inputs (min) 10 20 30 40 50 60 Monomer dissolution between inputs X X ○ ○ ○ ○ Property measurement Viscosity (23 ° C, cP) - - 5,500 5,300 5,600 5,500 460 ° C, 3hr, Td (%) - - 1.89 1.95 1.85 1.92 CTE (100 ~ 300 ℃ / ppm / ℃) - - 7.1 6.9 7.2 7.0 Tensile strength (MPa) - - 255 248 245 251 Elongation (%) - - 15 13 14 14

As shown in Table 2 above, the number of split feeds of acid dihydrate was fixed five times, and optimization evaluation of the time between split feeds was performed. In the case of Comparative Examples 4 to 5, the time between the split inputs was short, so that sufficient dissolution of the acid dihydrate monomer was not achieved. Therefore, the production of a proper polyamic acid was a heap. On the other hand, as in the case of Examples 2-1 to 2-4, the input time between the splitting of the acid dianhydride monomer was put at intervals of 30 to 60 minutes, so that sufficient dissolution of the acid dianhydride monomer was possible and a proper polyamic acid solution was obtained. . As shown in the results of the properties of Examples 2-1 to 2-4, if only sufficient dissolution time of the acid dianhydride monomer between the split inputs is given, it can be seen that the characteristics of the equivalent level depending on the time between split inputs. Through the above results, the time between the split input of the acid dianhydride monomer is 30 ~ 60 minutes is appropriate, 30 minutes is preferred.

<Polymerization temperature>

Example 2-1, 2-5 to 2-7, and Comparative Example 6

A polyamic acid resin was prepared in the same manner as in Example 1, except for the polymerization temperature of Table 3 and the excess molar ratio of the acid dianhydride monomer.

Experimental Example 3: Measurement of Physical Properties

A polyimide film was prepared in the same manner as in Experimental Example 1, physical properties were measured, and the results are shown in Table 3 below.

division Example 2-1 Example 2-5 Example 2-6 Example 2-7 Comparative Example 6 Polymerization conditions Acid dianhydride (unit: mol%) BPDA = 100 Diamine (Unit: mol%) PPD: TFMB = 95: 5 menstruum NMP Number of acid dianhydride splits 5 Acid dianhydride excess (%) 3.5 1.6 1.5 1.3 1.2 Time between split inputs (min) 30 Polymerization temperature (℃) 23 40 50 60 70 Property measurement Viscosity (23 ° C, cP) 5,500 5,600 5,400 5,800 5,400 460 ° C, 3hr, Td (%) 1.89 0.43 0.44 0.42 0.61 CTE (100 ~ 300 ℃ / ppm / ℃) 7.1 4.1 4.5 4.3 5.4 Tensile strength (MPa) 255 373 388 380 320 Elongation (%) 15 25 27 27 20

As shown in Table 3, it was fixed at the number of times the acid dihydrate was added (5 times), the time between the inputs (30 minutes), and the optimization evaluation of the polymerization temperature was performed. Compared with Example 2-1, as shown in the results of Examples 2-5 to 2-7, as the polymerization temperature was increased, the excess molar ratio of the acid dianhydride monomer was reduced, and the heat resistance and mechanical properties were increased while showing the same level of viscosity. It can be seen. Depending on the polymerization temperature of 40 to 60 ℃ of Examples 2-5 to 2-7 it can be seen that the characteristics of the equivalent level. On the other hand, the result of Comparative Example 6 shows that the excess molar ratio of the acid dianhydride monomer is reduced at the polymerization temperature of 70 ° C., and the characteristics are inferior to those of Examples 2-5 to 2-7 even at the same level of viscosity. Through the above results, the polymerization temperature is appropriately 40 ~ 60 ℃, 40 ℃ is preferred.

Through the above results, after dissolving the diamine monomer in an organic solvent, the dianhydride-based monomer is divided into four or more times at a polymerization temperature of 40 ~ 60 ℃, the input time is obtained by polymerization with a time difference of 30 to 60 minutes intervals In the case of polyamic acid resin, it turns out that the film which has the ease of laser peeling and high heat resistance can be manufactured.

<Reference Example>

Comparative Example 7

As a composition shown in Table 4, 41.536 g (0.130 mole) of TFMB, a diamine monomer, was dissolved in 455.04 g of NMP, an organic solvent, and dissolved in a nitrogen atmosphere at room temperature for 30 minutes to 1 hour. Thereafter, 38.765 g (0.132 mole) of BPDA, an dianhydride-based monomer, was added five times and stirred for 6 hours to prepare a polyamic acid. (Reaction temperature: 60 ℃ / 6 hours after stirring for 25 ℃, the solid content is to be maintained to 15% by weight relative to the total weight of the reaction solvent.) As a result of measuring by the viscosity measuring equipment (Brookfield DV2T, SC4-27), The viscosity was 6,000 cP.

Comparative Example 8

As a composition shown in Table 4 below, 21.329 g (0.197 mole) of a diamine monomer was dissolved in 455.04 g of NMP, an organic solvent, and dissolved in a nitrogen atmosphere at room temperature for 30 minutes to 1 hour. Thereafter, 58.971 g (0.200 mole) of BPDA, an dianhydride-based monomer, was added five times and stirred for 6 hours to prepare a polyamic acid. (Reaction temperature: 60 ℃ / 6 hours after stirring for 25 ℃, the solid content is to be maintained to 15% by weight relative to the total weight of the reaction solvent.) As a result of measuring by the viscosity measuring equipment (Brookfield DV2T, SC4-27), The viscosity was 6,100 cP.

Example 4

As a composition shown in Table 4, 19.748 g (0.182 mol) of diamine monomers and 3.079 g (0.010 mole) of TFMB were dissolved in 455.04 g of NMP, an organic solvent, and dissolved in a nitrogen atmosphere at room temperature for 30 minutes to 1 hour. Thereafter, 57.441 g (0.195 mole) of BPDA, an dianhydride-based monomer, was added five times and stirred for 6 hours to prepare a polyamic acid. (Reaction temperature: 40 ℃ / 6 hours after stirring for 25 ℃, the solid content is to be maintained to 15% by weight relative to the total weight of the reaction solvent.) As a result of measuring by the viscosity measuring equipment (Brookfield DV2T, SC4-27), The viscosity was 5,800 cP.

Example 5

As a composition shown in Table 4, 18.245 g (0.169 mol) of diamine monomers and 6.006 g (0.019 mole) of TFMB were dissolved in 455.04 g of NMP, an organic solvent, and dissolved in a nitrogen atmosphere at room temperature for 30 minutes to 1 hour. Thereafter, 55.983 g (0.190 mole) of BPDA, an dianhydride-based monomer, was added five times and stirred for 6 hours to prepare a polyamic acid. (Reaction temperature: 60 ℃ / 6 hours after stirring for 25 ℃, the solid content is to be maintained to 15% by weight relative to the total weight of the reaction solvent.) As a result of measuring by the viscosity measuring equipment (Brookfield DV2T, SC4-27), The viscosity was 5,300 cP.

Example 6

As a composition shown in Table 4, 8.460 g (0.078 mol) of a diamine monomer and TFMB 25.061 g (0.078 mole) were dissolved in 455.04 g of NMP, an organic solvent, and dissolved in a nitrogen atmosphere at room temperature for 30 minutes to 1 hour. Thereafter, 46.779 g (0.159 mole) of BPDA, an dianhydride-based monomer, was added five times and stirred for 6 hours to prepare a polyamic acid. (Reaction temperature: 60 ℃ / 6 hours after stirring for 25 ℃, the solid content is to be maintained to 15% by weight relative to the total weight of the reaction solvent.) As a result of measuring by the viscosity measuring equipment (Brookfield DV2T, SC4-27), The viscosity was 5,500 cP.

Example 7

As a composition shown in Table 4, 21.323 g (0.197 mol) of diamine monomers and 3.325 g (0.010 mole) of TFMB were dissolved in 455.04 g of NMP, an organic solvent, and dissolved in a nitrogen atmosphere at room temperature for 30 minutes to 1 hour. Thereafter, 37.234 g (0.126 mole) of dianhydride-based monomers and 18.419 g (0.084 mol) of PMDA were added five times and stirred for 6 hours to prepare a polyamic acid. (Reaction temperature: 60 ℃ / 24 hours after stirring for 25 ℃, the solid content is to be maintained to 15% by weight relative to the total weight of the reaction solvent.) As a result of measuring by the viscosity measuring equipment (Brookfield DV2T, SC4-27), The viscosity was 5,900 cP.

Experimental Example 4: Measurement of Physical Properties

A polyimide film was prepared in the same manner as in Experimental Example 1, the physical properties were measured, and the results are shown in Table 4 below.

division Example 4 Example 5 Example 6 Example 7 Comparative Example 7 Comparative Example 8 Composition Acid dianhydride (unit: mol%) BPDA 100 100 100 60 100 100 PMDA - - - 40 - - Diamine (unit: mol%) TFMB 5 10 50 5 100 - PPD 95 90 50 95 - 100 Number of split dianhydrides 5 Time between split inputs (min) 30 Polymerization temperature (℃) 40 Organic solvent NMP Property measurement division Target value Example 4 Example 5 Example 6 Example 7 Comparative Example 7 Comparative Example 8 Viscosity (cP, 23 ° C) 1000-7000 5800 5300 5500 5900 6000 6100 Thickness (㎛) 10-15 11 10 12 11 12 13 Adhesive force (N / cm) 0.5-2.0 1.8 1.5 0.8 2.0 <0.2 2.3 Laser Peel Energy (mJ / cm ² ) 0-200 180 180 140 200 100 220 460 ℃, 180min / weight loss (%) <1.0 0.42 0.46 1.48 0.21 3.32 0.30 CTE (100-350 ° C, ppm / ° C) ≤10 4.3 4.8 8.7 3.8 13.3 4.1 Tensile strength (MPa) > 300 380 383 341 383 314 302 Elongation (%) > 20 27 25 28 23 27 20

As shown in Table 4 above, in Examples 4 to 7 containing 5 to 50 mol% of 2,2'-bis (trifluoromethyl) -benzidine (TFMB), the adhesion strength of the glass substrate was 0.5 to 2.0 (N / cm) can be confirmed. By adjusting the content of TFMB, it is possible to control the adhesion. It has the proper adhesive force with the glass substrate to minimize the curl and product defects during peeling.

In addition, the laser can be peeled off at low energy during peeling, so peeling is possible without damaging the film. In addition, it was confirmed that also excellent in heat resistance and mechanical aspects. Comparative Example 7 is a case where the adhesive force is less than 0.2 (N / cm), the adhesive force is too weak, Comparative Example 8 is an adhesive force is too strong when the adhesive force is 2.3 (N / cm). Also, the laser peel energy is too high and may cause film damage during peeling. Such weak or strong adhesion will result in curls or product defects upon film peeling.

Therefore, the polyamic acid resin prepared according to the present invention has an adhesive force of 0.2 to 2.0 N / cm, a peel energy of 200 mJ / cm ² or less, and a thermal expansion coefficient of 10 ppm / ° C or less in a range of 100 to 350 ° C. It can be provided as a polyimide resin film.

Through these results, when the polyamic acid resin is prepared through the monomer split-input, the dosing time control and the optimization of the polymerization temperature according to the present invention, it has a low viscosity and excellent mechanical properties, heat resistance, and a low coefficient of thermal expansion. It can be widely used as an adhesive film on the glass substrate of the organic light emitting diode because it maintains the adhesive force and can be laser peeled at low energy so that it does not cause curl and product defects during peeling.

Claims (6)

In the manufacturing method of the polyamic-acid resin manufactured by superposing | polymerizing the composition containing a diamine-type monomer, an acid dianhydride compound, and an organic solvent, The polyamic acid resin is polymerized by dissolving the diamine monomer in an organic solvent and dividing the acid dianhydride compound four times or more, but the input time is added with a time difference of 30 to 60 minutes intervals and A method for producing a polyamic acid resin having high heat resistance. The method for producing a polyamic acid resin according to claim 1, wherein the addition is carried out by equally dividing the acid dianhydride compound 4 to 6 times at a polymerization temperature of 40 to 60 ° C. The method for producing a polyamic acid resin according to claim 1, wherein the dosing is performed by dividing the acid dianhydride compound five times at intervals of 30 minutes at a polymerization temperature of 40 ° C. According to claim 1, wherein the diamine monomer is 2 to 2'-bis (trifluoromethyl) -benzidine (2,2'-bis (trifluoromethyl) benzidine) 5 to 50 mol based on 100 mole% of the diamine monomer Method for producing a polyamic acid resin, characterized in that it comprises%. The method of claim 1, wherein the polyamic acid resin has a viscosity of 1,000 to 7,000 cp. A film prepared by heat-treating a polyamic acid resin prepared by the method according to any one of claims 1 to 5, wherein the film has a thickness of 10 to 15 µm, an adhesive force of 0.2 to 2.0 N / cm, and a peeling energy. 200 mJ / cm ² Hereinafter, the coefficient of thermal expansion in the range of 100-350 degreeC is 10 ppm / degrees C or less, The polyimide resin film characterized by the above-mentioned.

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