JP6257302B2 - POLYIMIDE PRECURSOR, RESIN COMPOSITION CONTAINING THE SAME, POLYIMIDE FILM AND ITS MANUFACTURING METHOD, AND LAMINATE AND ITS MANUFACTURING METHOD - Google Patents

Description

  The present invention relates to, for example, a polyimide precursor and a resin composition containing the polyimide precursor, a polyimide film and a manufacturing method thereof, and a laminate and a manufacturing method thereof, which are used for a substrate for a flexible device.

  Generally, a polyimide (PI) film is a polyimide resin film. Polyimide resin is a solution polymerization of an aromatic dianhydride and an aromatic diamine, and after producing a polyimide precursor, ring closure dehydration at high temperature, thermal imidization, or chemical imidization using a catalyst, It is a highly heat-resistant resin that is manufactured.

  Polyimide resin is an insoluble and infusible super heat-resistant resin, and has excellent characteristics such as heat oxidation resistance, heat resistance, radiation resistance, low temperature resistance, chemical resistance, etc. It is used in a wide range of fields including electronic materials such as films, semiconductors, and electrode protection films for TFT-LCDs, and recently, it is also used for display materials such as optical fibers and liquid crystal alignment films.

  However, polyimide resins are colored brown or yellow due to high aromatic ring density, have low transmittance in the visible light region, and have been difficult to use in fields where transparency is required.

  Patent Document 1 reports that a polyimide having a novel structure in which transmittance and hue transparency are improved by using an acid dianhydride and a diamine containing a specific structure.

  On the other hand, Patent Document 2 and Patent Document 3 disclose a polyimide film into which an alicyclic structure is introduced in order to impart transparency.

JP 2000-198843 A JP 2005-336243 A JP 2001-353113 A

  However, the mechanical characteristics and thermal characteristics of polyimide described in Patent Document 1 are not sufficient for use as, for example, a semiconductor insulating film, a TFT-LCD insulating film, an electrode protective film, and a flexible display substrate.

  In particular, the polyimide described in Patent Document 1 is characterized by a high coefficient of linear expansion (hereinafter also referred to as CTE). When the CTE is high, the degree of expansion and contraction of the film in response to a temperature change in the TFT process or the like increases, resulting in damage to the inorganic film used in the device, resulting in a reduction in device capability. For this reason, in order to use a polyimide resin for a substrate for forming a TFT, a substrate for forming a color filter, an alignment film, a transparent substrate for flexible display, etc., it must be colorless and transparent and have a low CTE.

  Moreover, although the polyimide described in Patent Document 2 has transparency, there is a concern that the CTE is high and the elongation at break is low. When the elongation at break is low, the flexible substrate is damaged when the flexible device is handled and cannot be used as a device. In the polyimide described in Patent Document 3, toughness is imparted by using a polycyclic aromatic diamine, but the CTE increases, and a semiconductor insulating film, a TFT-LCD insulating film, an electrode protective film, and a flexible display substrate It was not enough to use as.

  The present invention has been made in view of the above-described problems, and includes a polyimide precursor that can produce a polyimide film that is colorless and transparent, has a low CTE, and is excellent in elongation. An object of the present invention is to provide a resin composition, a polyimide film and a production method thereof, and a laminate and a production method thereof.

  As a result of intensive studies to solve the above problems, the present inventors have shown that polyimide obtained by imidizing a polyimide precursor having a specific structure exhibits excellent transparency, low linear expansion coefficient, and high elongation. Based on the finding and this finding, the present invention has been made. That is, the present invention is as follows.

  The polyimide precursor of the present invention has a structure derived from 2,2′-bis (trifluoromethyl) benzidine (TFMB) as a diamine-derived structure, and pyromellitic dianhydride (PMDA) as an acid dianhydride-derived structure. ) And 4,4′-oxydiphthalic dianhydride (ODPA) and 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and / or 1,2,4,5- It has a structure derived from cyclohexanetetracarboxylic dianhydride (H-PMDA).

  With this configuration, it is possible to produce a polyimide film that is colorless and transparent, has a low coefficient of linear expansion, and has a high elongation.

  In the polyimide precursor of the present invention, the TFMB-derived structure contains 60 mol% or more of the total diamine-derived structure, and the PMDA, the ODPA, the CBDA, and the H-PMDA-derived structure are combined in total acid dianhydride. It is preferable to contain 60 mol% or more in the product-derived structure.

  In the polyimide precursor of the present invention, the PMDA-derived structure is 1 to 70 mol% in the total acid dianhydride-derived structure, and the structure derived from the ODPA is 1 to 2 in the total acid dianhydride-derived structure. It is preferable to have 50 mol%.

Further, in the polyimide precursor of the present invention, the ratio of the sum of the number of moles of the structure derived from PMDA, ODPA, CBDA and H-PMDA to the number of moles of the structure derived from TFMB {(PMDA + ODPA + CBDA + H-PMDA) / TFMB} is preferably 100 / 99.9 to 100/95. Further, the polyimide precursor of the present invention comprises, as the acid dianhydride-derived structure, a structure derived from the PMDA and the ODPA, and a structure derived from at least the CBDA. It is preferable to have 10 to 50 mol% in the anhydride, 10 to 40 mol% in the total acid dianhydride, and 10 to 80 mol% in the total acid dianhydride. Further, in the polyimide precursor of the present invention, as the structure derived from the acid dianhydride, the structure derived from the PMDA and the ODPA, and the structure derived from at least the H-PMDA, It is preferable to have 30 to 65 mol% in acid dianhydride, 10 to 40 mol% in total acid dianhydride, and 4 to 60 mol% in H2PMDA in all acid dianhydrides. Moreover, in the polyimide precursor of this invention, it is preferable that a weight average molecular weight is 50000 or more.

  In the polyimide precursor of the present invention, after dissolving in a solvent and spreading on the surface of the support, the polyimide film obtained by imidization by heat treatment in a nitrogen atmosphere has a yellowness of 10 or less, a linear expansion coefficient of 25 ppm or less, And it is preferable that elongation at break is 15% or more.

  Moreover, it is preferable that the polyimide precursor of this invention is used for manufacture of a flexible device.

  The resin composition of the present invention comprises the polyimide precursor of the present invention described above and a solvent.

  The polyimide film of the present invention is formed by developing the resin composition of the present invention described above on the surface of a support, and then imidizing the polyimide precursor by heating the support and the resin composition. It is characterized by that.

  The method for producing a polyimide film of the present invention comprises the steps of developing the resin composition of the present invention described above on the surface of a support, and imidizing the polyimide precursor by heating the support and the resin composition. Forming a polyimide film and peeling the polyimide film from the support to obtain the polyimide film.

  The laminate of the present invention comprises a support and a polyimide film, the resin composition of the present invention described above is developed on the surface of the support, and the polyimide is heated by heating the support and the resin composition. It is obtained by imidizing a precursor to form the polyimide film.

  The method for producing a laminate of the present invention comprises the steps of developing the resin composition of the present invention described above on the surface of a support, and imidizing the polyimide precursor by heating the support and the resin composition. Forming a polyimide film and obtaining a laminate composed of the support and the polyimide film.

  According to the present invention, it is possible to produce a polyimide film that is colorless and transparent, has a low coefficient of linear expansion, and is excellent in elongation.

  Hereinafter, an embodiment of the present invention (hereinafter abbreviated as “embodiment”) will be described in detail. In addition, this invention is not limited to the following embodiment, It can implement by changing variously within the range of the summary.

  The polyimide precursor according to the present embodiment has a structure derived from 2,2′-bis (trifluoromethyl) benzidine (TFMB) as a diamine-derived structure, and pyromellitic dianhydride as a structure derived from an acid dianhydride. Structure (PMDA) and 4,4′-oxydiphthalic dianhydride (ODPA), and 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA) and / or 1,2,4 , 5-cyclohexanetetracarboxylic dianhydride (H-PMDA).

Hereinafter, each structure will be described in detail.
<Acid dianhydride-derived structure>
The polyimide precursor according to the present embodiment has a structure derived from pyromellitic dianhydride (hereinafter also referred to as PMDA) and a 4,4′-oxydiphthalic dianhydride (hereinafter referred to as “acid dianhydride derived structure”). And ODPA), 1,2,3,4-cyclobutanetetracarboxylic dianhydride (hereinafter also referred to as CBDA) and / or 1,2,4,5-cyclohexanetetracarboxylic dianhydride (Hereinafter also referred to as H-PMDA).

  That is, it has at least one of a structure derived from CBDA and a structure derived from H-PMDA as an alicyclic acid dianhydride, and a structure derived from PMDA and a structure derived from ODPM as another acid dianhydride derived structure.

  Here, 1,2,4,5-cyclohexanetetracarboxylic dianhydride (H-PMDA) includes isomers represented by the following general formulas (1) to (3). It may be.

  The polyimide precursor according to the present embodiment has a structure derived from pyromellitic dianhydride (PMDA), a structure derived from total acid dianhydride, from the viewpoint of obtaining a suitable yellowness, CTE and breaking strength of the polyimide film. It is preferable to have 1 to 70 mol% of the structure derived from 4,4′-oxydiphthalic dianhydride (ODPA) in the total acid dianhydride derived structure.

<Diamine-derived structure>
Further, the polyimide precursor according to the present embodiment has a structure derived from 2,2′-bis (trifluoromethyl) benzidine (hereinafter also referred to as TFMB) as a diamine-derived structure.

<Ratio of acid dianhydride-derived component and diamine-derived component>
The ratio {(PMDA + ODPA + CBDA + H-PMDA) / TFMB} of the sum of the number of moles of the acid dianhydride-derived component, that is, the structure derived from PMDA, ODPA, CBDA and H-PMDA, and the number of moles of the structure derived from TFMB is 100 / 99.9 to 100/95 is preferable from the viewpoint of obtaining suitable yellowness, CTE, and breaking strength in the polyimide film.

<Resin composition>
The polyimide precursor which concerns on this Embodiment as mentioned above is used as a resin composition (varnish) which melt | dissolved this in the solvent.

  As a more preferred embodiment, the resin composition contains the above-mentioned acid dianhydride component and diamine component dissolved in a solvent, for example, an organic solvent, and reacted to contain the polyamic acid which is one embodiment of the polyimide precursor and the solvent. It can be produced as a polyamic acid solution. Here, the conditions during the reaction are not particularly limited. For example, the reaction temperature is −20 to 100 ° C., and the reaction time is 2 to 48 hours. Moreover, it is preferable that it is inert atmosphere, such as argon and nitrogen, at the time of reaction.

  Moreover, the polyimide precursor which concerns on this Embodiment can be imidized in the range which melt | dissolves a part or all of the structure in a solvent, and can be set as a polyimide solution or a polyimide-polyamic acid solution.

  The step of synthesizing the polyimide moiety is not particularly limited, and a known method can be applied. More specifically, it is obtained by the following method. First, diamine is dissolved and / or dispersed in a polymerization solvent, acid dianhydride powder is added thereto, and a solvent azeotroped with water is added. Using a mechanical stirrer, the mixture is heated and stirred for 0.5 to 96 hours, preferably 0.5 to 30 hours, while removing by-product water azeotropically. In this case, the monomer concentration is 0.5% by mass or more and 95% by mass or less, preferably 1% by mass or more and 90% by mass or less.

  The polyimide portion may be synthesized by adding a known imidation catalyst or may be synthesized without a catalyst. The imidization catalyst is not particularly limited, but an acid anhydride such as acetic anhydride, a lactone compound such as γ-valerolactone, γ-butyrolactone, γ-tetronic acid, γ-phthalide, γ-coumarin, and γ-phthalido acid. , Tertiary amines such as pyridine, quinoline, N-methylmorpholine, triethylamine, and the like. Moreover, the imidation catalyst may be one kind or a mixture of two or more kinds as necessary. Among these, a mixed system of γ-valerolactone and pyridine is particularly preferable from the viewpoint of high reactivity, and no catalyst is particularly preferable from the viewpoint of influence on the next reaction.

  The amount of the imidization catalyst added is preferably 50 parts by mass or less, and more preferably 30 parts by mass or less when the polyamic acid is 100 parts by mass.

  The solvent is not particularly limited as long as it is a solvent that dissolves polyimide, polyamic acid, or a polymer of polyimide and polyamic acid. As a known reaction solvent, one kind selected from m-cresol, N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethylacetamide (DMAc), dimethyl sulfoxide (DMSO), acetone, and diethyl acetate The above polar solvents are useful. Of these, NMP and DMAc are preferable. In addition, a low-boiling solution such as tetrahydrofuran (THF) or chloroform, or a low-absorbing solvent such as γ-butyrolactone may be used.

  The weight average molecular weight of the polyimide precursor is preferably 5000 or more and 1000000 or less, more preferably 50000 or more and 500000 or less, and further preferably 70000 or more and 250,000 or less. When the weight average molecular weight is 5000 or more, the strength and elongation of the resin layer obtained using the resin composition is improved, and the mechanical properties are excellent. When the weight average molecular weight is 1,000,000 or less, coating can be performed without bleeding at a desired film thickness during processing such as coating. In particular, from the viewpoint of obtaining low CTE and low yellowness (YI value), the molecular weight is preferably 50,000 or more. Here, the weight average molecular weight refers to a molecular weight measured by gel permeation chromatography using polystyrene having a known number average molecular weight as a standard.

<Polyimide film>
The polyimide film according to the present embodiment develops the resin composition containing the polyimide precursor and the solvent according to the above-described embodiment (hereinafter also referred to as a polyimide precursor solution) on the surface of the support, Next, the support and the resin composition are heated to imidize the polyimide precursor. More specifically, as described above, a polyamic acid solution obtained by dissolving and reacting an acid dianhydride component and a diamine component in an organic solvent can be used.

  Here, the support is, for example, an inorganic substrate such as a glass substrate such as an alkali-free glass substrate, but is not particularly limited.

  More specifically, the polyimide precursor solution described above is spread and dried on the adhesive layer formed on the main surface of the inorganic substrate, and cured at a temperature of 250 to 500 ° C. in an inert atmosphere. A polyimide film can be formed.

  Here, examples of the developing method include known coating methods such as spin coating, slit coating, and blade coating. In addition, after the polyamic acid solution is spread on the adhesive layer, the heat treatment is heat-treated at a temperature of 250 ° C. or lower for 1 to 300 minutes mainly for the purpose of solvent removal, and further 250 to 550 ° C. under an inert atmosphere such as nitrogen A polyimide precursor is converted into a polyimide by heat treatment at a temperature of 1 ° C. for 1 minute to 300 minutes.

  Moreover, the thickness of the polyimide film according to the present embodiment is not particularly limited, and is preferably in the range of 10 to 50 μm, more preferably 15 to 25 μm.

<Laminated body>
The laminate according to the present embodiment includes a support and a polyimide film, the resin composition according to the present embodiment is developed on the surface of the support, and the support and the resin composition are heated to obtain a polyimide precursor. It is obtained by imidizing the body to form a polyimide film.

  This laminated body is used for manufacturing a flexible device, for example. More specifically, a semiconductor device can be formed on a polyimide film, and then a support can be peeled off to obtain a flexible device including a flexible transparent substrate made of a polyimide film.

  As described above, the polyimide precursor according to the present embodiment includes (1) at least one alicyclic acid dianhydride selected from CBDA and H-PMDA as the structure derived from acid dianhydride, PMDA, and Since it has a structure derived from each of OPDA and (2) a structure derived from TFMB as a structure derived from diamine, a polyimide film produced using this structure is colorless and transparent, has a low CTE, and further exhibits elongation. Therefore, it is suitable for use on a transparent substrate of a flexible display.

  More specifically, when a flexible display is formed, a flexible substrate is formed thereon using a glass substrate as a support, and a TFT or the like is formed thereon. The process of forming the TFT on the substrate is typically performed at a wide temperature range of 150 to 650 ° C. However, in order to actually realize the desired performance, the temperature is mainly from 250 ° C. to 400 ° C. Within a range, a TFT-IGZO (InGaZnO) oxide semiconductor or a TFT (a-Si-TFT, poly-Si-TFT) is formed using an inorganic material.

  At this time, if the CTE of the flexible substrate is higher than that of the glass substrate, problems such as warpage or breakage of the glass substrate, peeling of the flexible substrate from the glass substrate when shrinking during normal temperature cooling after expansion in a high temperature TFT process Occurs. In general, since the thermal expansion coefficient of the glass substrate is smaller than that of the resin, the lower the linear expansion coefficient of the flexible substrate, the better. The polyimide film according to the present embodiment takes into account this point, It is preferable that an average linear expansion coefficient (CTE) measured at 100 to 300 ° C. is 25.0 ppm / ° C. or less according to the TMA method on the basis of 15 to 25 μm.

  In addition, the polyimide film according to the present embodiment has a yellowness (YI value) of 10 or less, and a transmittance of 550 nm when measured with an ultraviolet spectrophotometer on the basis of the film thickness of 15 to 25 μm. The transmittance is preferably 85% or more.

  In addition, the polyimide film according to the present embodiment has an elongation of 15% or more on the basis of the film thickness of 15 to 25 μm from the viewpoint of improving yield by being excellent in breaking strength when handling a flexible substrate. Preferably there is.

  The polyimide film according to the present embodiment satisfying the above physical properties is used as a transparent substrate for flexible displays, in particular, the use of which is limited by the yellow color of the existing polyimide film. Furthermore, for example, it can be used in fields requiring transparency such as a protective film or a light-diffusing sheet and a coating film (for example, TFT-LCD interlayer, gate insulating film, and liquid crystal alignment film) in TFT-LCD. It is. When the polyimide according to this embodiment is applied as the liquid crystal alignment film, it contributes to an increase in the aperture ratio, and a TFT-LCD with a high contrast ratio can be manufactured.

  The polyimide film and laminate produced using the polyimide precursor according to the present embodiment are particularly suitable as a substrate, for example, for the production of semiconductor insulation films, TFT-LCD insulation films, electrode protection films, and flexible devices. Can be used. Here, examples of the flexible device include a flexible display, a flexible solar cell, flexible lighting, and a flexible battery.

  EXAMPLES Hereinafter, although this invention is further explained in full detail based on an Example, these are described for description and the range of this invention is not limited to the following Example.

Various evaluations in Examples and Comparative Examples were performed as follows.
(Measurement of weight average molecular weight)
The weight average molecular weight was measured by gel permeation chromatography (GPC) under the following conditions. As the solvent, N, N-dimethylformamide (manufactured by Wako Pure Chemical Industries, Ltd., for high performance liquid chromatograph) was used, and 24.8 mmol / L lithium bromide monohydrate (manufactured by Wako Pure Chemical Industries, Ltd.) before the measurement. , Purity 99.5%) and 63.2 mmol / L phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd., for high performance liquid chromatograph) were used. A calibration curve for calculating the weight average molecular weight was prepared using standard polystyrene (manufactured by Tosoh Corporation).
Column: Shodex KD-806M (manufactured by Showa Denko KK)
Flow rate: 1.0 mL / min Column temperature: 40 ° C
Pump: PU-2080 Plus (manufactured by JASCO)
Detector: RI-2031Plus (RI: differential refractometer, manufactured by JASCO), UV-2075Plus (UV-VIS: UV-visible light spectrometer, manufactured by JASCO)

(Production of laminate and isolated film)
The polyimide precursor is coated on a non-alkali glass substrate (thickness 0.7 mm) with a bar coater, leveled at room temperature for 5 to 10 minutes, heated in a hot air oven at 140 ° C. for 60 minutes, and further in a nitrogen atmosphere Under heating at a predetermined temperature for 60 minutes, a laminate was produced. The film thickness of the resin composition of the laminate was 20 μm. After curing (curing treatment) at a predetermined temperature, the laminate was allowed to stand at room temperature for 24 hours, and the polyimide film was peeled off from the glass to isolate the film. In the following evaluation of breaking strength, yellowness, and linear expansion coefficient, a polyimide film cured at the predetermined temperature was used as a sample.

(Evaluation of elongation)
A polyimide film having a sample length of 5 × 50 mm and a thickness of 20 μm cured at a predetermined temperature was subjected to tensile measurement at a speed of 100 mm / min using a tensile tester (manufactured by A & D Co., Ltd .: RTG-1210). A breaking elongation of 20% or more was evaluated as ◎, 15% or more and less than 20% as ○, 10% or more and less than 15% as Δ, and less than 10% as ×.

(Evaluation of yellowness (YI value))
A polyimide film having a thickness of 20 μm cured at a predetermined temperature was measured with a D65 light source by Nippon Denshoku Industries Co., Ltd. (Spectrophotometer: SE600). A YI value of 8.0 or less was evaluated as “◎”, a value of more than 8.0 or less than 10.0 was evaluated as “◯”, a value of 10.0 or higher as 15.0 or less as “Δ”, and a value of more than 15.0 as “X”.

(Evaluation of linear expansion coefficient (CTE))
The polyimide film cured at a predetermined temperature was subjected to a thermomechanical analysis using a thermomechanical analyzer (TMA-50) manufactured by Shimadzu Corporation under a load of 5 g, a heating rate of 10 ° C./min, and under a nitrogen atmosphere (flow rate 20 ml / min). ), The specimen elongation in the temperature range of 50 to 450 ° C. was measured, and the CTE of the polyimide film at 100 to 300 ° C. was determined. CTE of 20 ppm / ° C. or less was evaluated as “◎”, 20 ppm / ° C. or more and 25 ppm / ° C. or less as “◯”, 25 ppm / ° C. or more as 30 ppm / ° C. or less as “Δ”, and 30 ppm / ° C. or more as “X”.

[Example 1]
In a 500 ml separable flask under nitrogen atmosphere, 15.69 g (49.00 mmol) of 2,2′-bis (trifluoromethyl) benzidine (TFMB) and 178.95 g of N-methyl-2-pyrrolidone (NMP) were placed. TFMB was stirred and dissolved. Thereafter, 1.09 g (5.0 mmol) of pyromellitic dianhydride (PMDA), 3.10 g (10.0 mmol) of 4,4′-oxydiphthalic dianhydride (ODPA), 1, 2, 3, 4.86 g (35.0 mmol) of 4-cyclobutanetetracarboxylic dianhydride (CBDA) was added and stirred at 80 ° C. for 4 hours to obtain an NMP solution of polyamic acid (hereinafter also referred to as varnish). The obtained polyamic acid had a weight average molecular weight (Mw) of 116,500. Table 1 shows the CTE, YI value and elongation of the film cured at 330 ° C.

[Example 2]
TFMB 15.69 g (49.0 mmol), NMP 180.42 g, PMDA 3.27 g (15.0 mmol), ODPA 3.10 g (10.0 mmol), CBDA 4.90 g (25.0 mmol) A varnish was obtained in the same manner as in Example 1 except for the change. The resulting polyamic acid had a weight average molecular weight (Mw) of 120,000. Table 1 shows the CTE, YI value and elongation of the film cured at 330 ° C.

[Example 3]
TFMB 15.69 g (49.0 mmol), NMP 188.68 g, PMDA 1.09 g (5.00 mmol), ODPA 6.20 g (20.0 mmol), CBDA 4.90 g (25.0 mmol) A varnish was obtained in the same manner as in Example 1 except for the change. The obtained polyamic acid had a weight average molecular weight (Mw) of 128,000. Table 1 shows the CTE, YI value and elongation of the film cured at 330 ° C.

[Example 4]
Under a nitrogen atmosphere, 3.14 g (9.8 mmol) of TFMB, 16.14 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 2.24 g (10.0 mmol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride (H-PMDA) was added and refluxed at 180 ° C. for 2 hours, followed by azeotropy over 3 hours. The solvent toluene was removed. After cooling to 40 ° C., 12.55 g (39.2 mmol) of TFMB, 168.43 g of NMP, 6.54 g (30.0 mmol) of PMDA, and 3.10 g (10.0 mmol) of ODPA were added at 80 ° C. The mixture was stirred for 4 hours to obtain a varnish of a polyimide-polyamic acid polymerization composition. The obtained polyimide-polyamic acid polymerization composition had a weight average molecular weight (Mw) of 82,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Example 5]
TFMB was changed to 15.69 g (49.0 mmol), NMP was 178.14 g, PMDA was changed to 5.45 g (25.0 mmol), ODPA was changed to 1.55 g (5.0 mmol), and CBDA was changed to 3.92 g (20 mmol). Except for the above, a varnish was obtained in the same manner as in Example 1. The obtained polyamic acid had a weight average molecular weight (Mw) of 119,000. Table 1 shows the CTE, YI value and elongation of the film cured at 330 ° C.

[Example 6]
TFMB 15.69 g (49.0 mmol), NMP 187.38 g, PMDA 2.18 g (10.0 mmol), ODPA 6.20 g (20.0 mmol), CBDA 3.92 g (20.0 mmol) A varnish was obtained in the same manner as in Example 1 except for the change. The resulting polyamic acid had a weight average molecular weight (Mw) of 123,000. Table 1 shows the CTE, YI value and elongation of the film cured at 330 ° C.

[Example 7]
TFMB 15.69 g (49.0 mmol), NMP 175.19 g, PMDA 1.09 g (5.0 mmol), ODPA 1.55 g (5.0 mmol), CBDA 7.84 g (40.0 mmol) A varnish was obtained in the same manner as in Example 1 except for the change. The resulting polyamic acid had a weight average molecular weight (Mw) of 123,000. Table 1 shows the CTE, YI value and elongation of the film cured at 330 ° C.

[Example 8]
TFMB 15.69 g (49.0 mmol), NMP 189.59 g, PMDA 5.45 g (25.0 mmol), ODPA 6.20 g (20.0 mmol), CBDA 0.98 g (5.0 mmol) A varnish was obtained in the same manner as in Example 1 except for the change. The resulting polyamic acid had a weight average molecular weight (Mw) of 103,000. Table 1 shows the CTE, YI value and elongation of the film cured at 330 ° C.

[Example 9]
Under a nitrogen atmosphere, 3.14 g (9.8 mmol) of TFMB, 16.14 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 2.24 g (10.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 12.55 g (39.2 mmol) of TFMB, 171.51 g of NMP, 5.45 g (25.0 mmol) of PMDA, and 4.65 g (15.0 mmol) of ODPA were added at 80 ° C. The mixture was stirred for 4 hours to obtain a varnish of a polyimide-polyamic acid polymerization composition. The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymerization composition was 123,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Example 10]
Under a nitrogen atmosphere, 3.14 g (9.8 mmol) of TFMB, 16.14 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 2.24 g (10.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 12.55 g (39.2 mmol) of TFMB, 174.59 g of NMP, 4.36 g (20.0 mmol) of PMDA, and 6.20 g (20.0 mmol) of ODPA were added at 80 ° C. The mixture was stirred for 4 hours to obtain a varnish of a polyimide-polyamic acid polymerization composition. The resulting polyimide-polyamic acid polymerization composition had a weight average molecular weight (Mw) of 81,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Example 11]
Under a nitrogen atmosphere, 6.28 g (19.6 mmol) of TFMB, 32.28 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. To this, 4.48 g (20.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 9.42 g (29.4 mmol) of TFMB, 76.44 g of NMP, 5.45 g (25.0 mmol) of PMDA, and 1.55 g (5.0 mmol) of ODPA were added at 80 ° C. The mixture was stirred for 4 hours to obtain a varnish of a polyimide-polyamic acid polymerization composition. The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymerization composition was 68,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Example 12]
Under a nitrogen atmosphere, 6.28 g (19.6 mmol) of TFMB, 32.28 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. To this, 4.48 g (20.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 9.42 g (29.4 mmol) of TFMB, 78.28 g of NMP, 4.36 g (20.0 mmol) of PMDA, and 3.10 g (10.0 mmol) of ODPA were added at 80 ° C. The mixture was stirred for 4 hours to obtain a varnish of a polyimide-polyamic acid polymerization composition. The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymerization composition was 68,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Example 13]
Under a nitrogen atmosphere, 0.63 g (1.96 mmol) of TFMB, 3.22 g of NMP, and 30 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 0.45 g (2.00 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 15.06 g (47.0 mmol) of TFMB, 186.57 g of NMP, 6.33 g (29.0 mmol) of PMDA, and 5.89 g (19.0 mmol) of ODPA were added at 80 ° C. The mixture was stirred for 4 hours to obtain a varnish of a polyimide-polyamic acid polymerization composition. The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymerization composition was 112,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Example 14]
Under a nitrogen atmosphere, 3.14 g (9.8 mmol) of TFMB, 16.14 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 2.24 g (10.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 12.55 g (39.2 mmol) of TFMB, 166.88 g of NMP, 7.09 g (32.5 mmol) of PMDA, and 2.33 g (7.5 mmol) of ODPA were added at 80 ° C. The mixture was stirred for 4 hours to obtain a varnish of a polyimide-polyamic acid polymerization composition. The obtained polyimide-polyamic acid polymerization composition had a weight average molecular weight (Mw) of 79,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Example 15]
Under a nitrogen atmosphere, 9.42 g (29.4 mmol) of TFMB, 48.42 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 6.78 g (30.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 6.28 g (19.6 mmol) of TFMB, 60.54 g of NMP, 3.27 g (15.0 mmol) of PMDA, and 1.55 g (5.0 mmol) of ODPA were added at 80 ° C. The mixture was stirred for 4 hours to obtain a varnish of a polyimide-polyamic acid polymerization composition. The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymerization composition was 56,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Example 16]
Under a nitrogen atmosphere, 3.14 g (9.80 mmol) of TFMB, 16.14 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 2.24 g (10.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 12.55 g (39.2 mmol) of TFMB, 168.43 g of NMP, 4.36 g (20.0 mmol) of PMDA, 3.10 g (10.0 mmol) of ODPA, and 1.10 g of CBDA. 96 g (10.0 mmol) was added and stirred at 80 ° C. for 4 hours to obtain a varnish of a polyimide-polyamic acid polymerization composition. The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymerization composition was 71,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Comparative Example 1]
Example 1 except that 14.39 g (44.9 mmol) of TFMB, 163.23 g of NMP, 10.0 g (45.8 mmol) of PMDA, 0 g (0 mmol) of ODPA, and 0 g (0 mmol) of CBDA were changed. In the same manner, a varnish was obtained. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish was 47,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Comparative Example 2]
Example 1 except that 10.12 g (31.6 mmol) of TFMB, 134.65 g of NMP, 0 g (0 mmol) of PMDA, 10.0 g (32.2 mmol) of ODPA, and 0 g (0 mmol) of CBDA were changed. In the same manner, a varnish was obtained. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish was 65,500. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Comparative Example 3]
Example 1 except that TFMB was changed to 16.00 g (50.0 mmol), NMP was 174.00 g, PMDA was changed to 0 g (0 mmol), ODPA was changed to 0 g (0 mmol), and CBDA was changed to 10.00 g (51.0 mmol). In the same manner, a varnish was obtained. The weight average molecular weight (Mw) of the polyamic acid in the obtained varnish was 221,000. Table 1 shows the CTE, YI value and elongation of the film cured at 330 ° C.

[Comparative Example 4]
Under a nitrogen atmosphere, 14.00 g (43.7 mmol) of TFMB, 160.62 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 10.00 g (44.6 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. Thereafter, it was cooled to room temperature to obtain a polyimide varnish. The weight average molecular weight (Mw) of the polyimide in the obtained varnish was 50,600. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Comparative Example 5]
Except for changing TFMB to 8.79 g (27.4 mmol), NMP to 60.6 g, PMDA to 5.50 g (25.2 mmol), ODPA to 0.87 g (2.8 mmol), and CBDA to 0 g (0 mmol). A varnish was obtained in the same manner as in Example 1. The weight average molecular weight (Mw) of the obtained varnish was 47,000. Table 1 shows the CTE, YI value and breaking strength of the film cured at 350 ° C.

[Comparative Example 6]
TFMB was changed to 16.44 g (51.3 mmol), NMP was 184.18 g, PMDA was 8.00 g (36.7 mmol), ODPA was changed to 0 g (0 mmol), and CBDA was changed to 3.08 g (15.7 mmol). A varnish was obtained in the same manner as in Example 1. The weight average molecular weight (Mw) of the obtained varnish was 121,900. Table 1 shows the CTE, YI value and breaking strength of the film cured at 330 ° C.

[Comparative Example 7]
TFMB was changed to 14.17 g (44.2 mmol), NMP was 171.31 g, PMDA was changed to 0 g (0 mmol), ODPA was changed to 7.00 g (22.6 mmol), and CBDA was changed to 4.43 g (22.6 mmol). A varnish was obtained in the same manner as in Example 1. The weight average molecular weight (Mw) of the obtained varnish was 105,000. Table 1 shows the CTE, YI value and breaking strength of the film cured at 330 ° C.

[Comparative Example 8]
Under a nitrogen atmosphere, 3.14 g (9.8 mmol) of TFMB, 16.14 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 2.24 g (10.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 12.55 g (39.2 mmol) of TFMB, 186.91 g of NMP and 12.41 g (40.0 mmol) of ODPA were added and stirred at 80 ° C. for 4 hours, and polyimide-polyamic acid polymerization composition A varnish was obtained. The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymerization composition was 66,700. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Comparative Example 9]
TFMB was changed to 15.69 g (49.0 mmol), NMP was 175.05 g, PMDA was 6.54 g (30.0 mmol), ODPA was changed to 0 g (0 mmol), and CBDA was changed to 3.92 g (20.0 mmol). A varnish was obtained in the same manner as in Example 1. The weight average molecular weight (Mw) of the obtained varnish was 91,200. Table 1 shows the CTE, YI value and breaking strength of the film cured at 330 ° C.

[Comparative Example 10]
Under a nitrogen atmosphere, 3.14 g (9.8 mmol) of TFMB, 16.14 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. Thereto, 2.24 g (10.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 12.55 g (39.2 mmol) of TFMB, 162.26 g of NMP, and 8.72 g (40.0 mmol) of PMDA were added and stirred at 80 ° C. for 4 hours to obtain a polyimide-polyamic acid polymerization composition. The varnish was obtained. The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymerization composition was 226,000. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

[Comparative Example 11]
Except for changing TFMB to 15.69 g (49.0 mmol), NMP to 193.54 g, PMDA to 0 g (0 mmol), ODPA to 9.31 g (30.0 mmol), and CBDA to 3.92 g (20.0 mmol) A varnish was obtained in the same manner as in Example 1. The weight average molecular weight (Mw) of the obtained varnish was 125,100. Table 1 shows the CTE, YI value and breaking strength of the film cured at 330 ° C.

[Comparative Example 12]
TFMB was changed to 15.69 g (49.0 mmol), NMP was 178.27 g, PMDA was changed to 0 g (0 mmol), ODPA was changed to 3.10 g (10.0 mmol), and CBDA was changed to 7.84 g (40.0 mmol). A varnish was obtained in the same manner as in Example 1. The weight average molecular weight (Mw) of the obtained varnish was 120,900. Table 1 shows the CTE, YI value and breaking strength of the film cured at 330 ° C.

[Comparative Example 13]
Under a nitrogen atmosphere, 12.55 g (39.2 mmol) of TFMB, 64.56 g of NMP, and 50 g of toluene were placed in a separable flask equipped with a Dean Stark apparatus and a refluxer, and TFMB was stirred and dissolved. To this, 8.97 g (40.0 mmol) of H-PMDA was added and refluxed at 180 ° C. for 2 hours, and then toluene as an azeotropic solvent was removed over 3 hours. After cooling to 40 ° C., 3.14 g (9.8 mmol) of TFMB, 46.48 g of NMP and 3.1 g (10.0 mmol) of ODPA were added and stirred for 4 hours at 80 ° C., and polyimide-polyamic acid polymerization composition A varnish was obtained. The weight average molecular weight (Mw) of the obtained polyimide-polyamic acid polymerization composition was 49,800. Table 1 shows the CTE, YI value and elongation of the film cured at 350 ° C.

As shown in Table 1, from the evaluation results of Examples 1 to 16, a polyimide film using a polyimide precursor having a structure derived from alicyclic acid dianhydride, PMDA, and ODPA is as follows. It was confirmed that the above conditions were satisfied at the same time.
(1) CTE is 25 ppm or less (2) YI value is 10 or less (3) Elongation is 15% or more

  Moreover, from the evaluation results of Comparative Examples 1 to 4, the polyimide film using the polyimide precursor having a structure derived from one kind of acid dianhydride satisfies all the above film properties (1) to (3). In the polyimide film using the polyimide precursor which has the structure derived from two types of acid dianhydrides from the evaluation result of Comparative Examples 5-13, about (1)-(3) all the film | membrane physical properties. It was confirmed that sufficient performance was not achieved.

  From this result, when the polyimide precursor has a structure derived from alicyclic dianhydride, PMDA, and ODPA, a polyimide film that is colorless and transparent, has a low coefficient of linear expansion, and is excellent in elongation. It was confirmed that it could be manufactured.

  The present invention can be suitably used as a substrate, for example, in the production of semiconductor insulating films, TFT-LCD insulating films, electrode protective films, and flexible displays.

Claims (14)

As a diamine-derived structure, a structure derived from 2,2′-bis (trifluoromethyl) benzidine (TFMB);
As a structure derived from acid dianhydride, a structure derived from pyromellitic dianhydride (PMDA) and 4,4′-oxydiphthalic dianhydride (ODPA), and 1,2,3,4-cyclobutanetetracarboxylic acid A structure derived from anhydride (CBDA) and / or 1,2,4,5-cyclohexanetetracarboxylic dianhydride (H-PMDA);
A polyimide precursor characterized by comprising:   The TFMB-derived structure contains 60 mol% or more of the total diamine-derived structure, and the PMDA, the ODPA, the CBDA, and the H-PMDA-derived structure are combined in a total acid dianhydride-derived structure of 60 mol% or more. The polyimide precursor according to claim 1, comprising:   The structure derived from the PMDA has 1 to 70 mol% in the total acid dianhydride-derived structure, and the structure derived from the ODPA has 1 to 50 mol% in the total acid dianhydride-derived structure. Item 3. The polyimide precursor according to item 1 or 2.   The ratio {(PMDA + ODPA + CBDA + H-PMDA) / TFMB} of the sum of the number of moles of the structure derived from PMDA, ODPA, CBDA and H-PMDA to the number of moles of the structure derived from TFMB is 100 / 99.9. It is -100/95, The polyimide precursor in any one of Claims 1-3 characterized by the above-mentioned. The acid dianhydride-derived structure comprises a structure derived from the PMDA and the ODPA, and a structure derived from at least the CBDA,
The PMDA has 10 to 50 mol% in total acid dianhydride, the ODPA has 10 to 40 mol% in total acid dianhydride, and the CBDA has 10 to 80 mol% in total acid dianhydride. The polyimide precursor according to any one of claims 1 to 4, wherein the polyimide precursor is characterized. The acid dianhydride-derived structure comprises a structure derived from the PMDA and the ODPA, and a structure derived from at least the H-PMDA,
The PMDA has 30-65 mol% in total acid dianhydride, the ODPA has 10-40 mol% in total acid dianhydride, and the H-PMDA has 4-60 mol% in total acid dianhydride. The polyimide precursor according to any one of claims 1 to 4, characterized in that: The weight average molecular weight is 50000 or more, The polyimide precursor in any one of Claims 1-6 characterized by the above-mentioned. After dissolving in a solvent and spreading on the surface of the support, the polyimide film obtained by imidization by heating in a nitrogen atmosphere has a yellowness of 10 or less, a linear expansion coefficient of 25 ppm or less, and a film thickness of 20 μm. the polyimide precursor according to any one of claims 1 to 7 in which the elongation is equal to or 15% or more. It is used for manufacture of a flexible device, The polyimide precursor in any one of Claims 1-8 characterized by the above-mentioned. A resin composition comprising the polyimide precursor according to any one of claims 1 to 9 and a solvent. A polyimide film formed by spreading the resin composition according to claim 10 on a surface of a support, and then imidizing the polyimide precursor by heating the support and the resin composition. . A step of spreading the resin composition according to claim 10 on a surface of a support, a step of heating the support and the resin composition to imidize the polyimide precursor to form a polyimide film, and the polyimide And a step of peeling the film from the support to obtain the polyimide film. A support and a polyimide film are provided, and the resin composition according to claim 10 is spread on the surface of the support, and the polyimide precursor is imidized by heating the support and the resin composition. A laminate obtained by forming a film. The step of developing the resin composition according to claim 10 on the surface of the support, heating the support and the resin composition to imidize the polyimide precursor to form a polyimide film, and the support and And a step of obtaining a laminate composed of the polyimide film.