Polyimide precursor and polyimide

Abstract

The present invention relates to a polyimide precursor comprising a repeating unit represented by the following chemical formula (1): ##STR00001##
wherein A is a tetravalent group having at least one aliphatic six membered ring and no aromatic ring in the chemical structure, and B is a divalent group having at least one amide bond and an aromatic ring in the chemical structure; or A is an aliphatic tetravalent group and B is a divalent group having at least one chemical structure represented by the following chemical formula (2) in the chemical structure: ##STR00002##
and X.sub.1 and X.sub.2 are each independently hydrogen, a C.sub.1-6 alkyl group or a C.sub.3-9 alkylsilyl group.

Claims

1. A polyimide precursor comprising a repeating unit represented by the following chemical formula (1): ##STR00031## wherein A is a tetravalent group having a plurality of aliphatic six-membered rings and no aromatic ring in the chemical structure, with the proviso that the plurality of six-membered rings may have two common carbon atoms as constituents, and B is at least one selected from the group consisting of the following chemical formulae (4-1) to (4-3): ##STR00032## wherein Ar.sub.1, Ar.sub.2 and Ar.sub.3 are each independently a divalent group of benzene, biphenyl, terphenyl, naphthalene or anthracene, which may be substituted with C.sub.1-3 alkyl group, halogen group, nitro group, hydroxyl group or carboxylic group, and n1 is an integer of 0 to 5; ##STR00033## wherein Ar.sub.4, Ar.sub.5, Ar.sub.6, Ar.sub.7 and Ar.sub.8 are each independently a divalent group of benzene, biphenyl, terphenyl, naphthalene or anthracene, which may be substituted with C.sub.1-3 alkyl group, halogen group, nitro group, hydroxyl group or carboxylic group, and n2 is an integer of 0 to 5; wherein Ar.sub.9, Ar.sub.10, Ar.sub.11, Ar.sub.12 and Ar.sub.13 are each independently a divalent group of benzene, biphenyl, terphenyl, naphthalene or anthracene, which may be substituted with C.sub.1-3 alkyl group, halogen group, nitro group, hydroxyl group or carboxylic group, and n3 is an integer of 0 to 5; or ##STR00034## wherein Ar.sub.9, Ar.sub.10, Ar.sub.11, Ar.sub.12 and Ar.sub.13 are each independently a divalent group of benzene, biphenyl, terphenyl, naphthalene or anthracene, which may be substituted with C.sub.1-3 alkyl group, halogen group, nitro group, hydroxyl group or carboxylic group, and n3 is an integer of 0 to 5; or B is a divalent group having at least one chemical structure represented by the following chemical formula (2) in the chemical structure: ##STR00035## and X.sub.1 and X.sub.2 are each independently hydrogen, a C.sub.1-6 alkyl group or a C.sub.3-9 alkylsilyl group.

2. The polyimide precursor according to claim 1, wherein the six-membered rings in A have a crosslinked cyclic form, in which carbon atoms constituting the ring chemically bind to each other to form another ring.

3. The polyimide precursor according to claim 1, wherein A is a group of the following chemical formula (3-2): ##STR00036## wherein R1 is a direct bond, a CH.sub.2 group, a C(CH.sub.3).sub.2 group, an SO.sub.2 group, an Si(CH.sub.3).sub.2 group, a C(CF.sub.3).sub.2 group, an oxygen atom or a sulfur atom.

4. The polyimide precursor according to claim 1, wherein A is a group of the following chemical formula (3-4): ##STR00037## wherein R3 and R4 are each independently a CH.sub.2 group, a CH.sub.2CH.sub.2 group, an oxygen atom or a sulfur atom.

5. The polyimide precursor according to claim 1, wherein B is at least one selected from the group consisting of the chemical formulae (4-1) to (4-3).

6. The polyimide precursor according to claim 5, wherein Ar.sub.1 to Ar.sub.13 in the chemical formula (4-1) to (4-3) are each independently a benzyl or biphenyl divalent group.

7. The polyimide precursor according to claim 6, wherein the bonding position of benzene or biphenyl as Ar.sub.1 to Ar.sub.13 for forming a polyimide main chain is the para position.

8. The polyimide precursor according to claim 1, wherein B is a group of the following chemical formula (4-4): ##STR00038## wherein Ar.sub.14 and Ar.sub.15 are each independently a divalent aromatic group having 6 to 18 carbon atoms; and R5 is a hydrogen atom or a monovalent organic group.

9. The polyimide precursor according to claim 1, obtained from a tetracarboxylic acid component providing the repeating unit represented by chemical formula (1) in an amount of 70 mole % or more and other tetracarboxylic acid components in an amount of 30 mole % or less based on 100 mole % of the total tetracarboxylic acid components, and a diamine component providing the repeating unit represented by chemical formula (1) in an amount of 70 mole % or more and other diamine components in an amount of 30 mole % or less based on 100 mole % of the total diamine components.

10. The polyimide precursor according to claim 9, wherein the other diamine component is at least one selected from the group consisting of oxydianiline, p-phenylenediamine, m-phenylenediamine, benzidine, 3,3′-dimethylbenzidine, 2,2′-dimethylbenzidine, p-methylene bis(phenylenediamine), bis(aminophenoxy)benzene, bis[(aminophenoxy)phenyl]hexafluoropropane, bis(aminophenyl)hexafluoropropane, bis(aminophenyl)sulfone, bis(trifluoromethyl)benzidine, cyclohexane diamine, bis[(aminophenoxy)phenyl]propane, bis(aminohydroxyphenyl)hexafluoropropane, and bis[(aminophenoxy)diphenyl]sulfone.

11. The polyimide precursor according to claim 1, obtained from a tetracarboxylic acid component having a purity of 99% or more and a diamine component having a purity of 99% or more, wherein in the case that plural stereoisomers are contained, the purity is determined by regarding the stereoisomers as a single component without distinguishing them.

12. The polyimide precursor according to claim 1, obtained from a tetracarboxylic acid component having a light transmittance of 70% or more and a diamine component having a light transmittance of 30% or more, wherein the light transmittance of the tetracarboxylic acid component is a transmittance at a wavelength of 400 nm and an optical path length of 1 cm as a 10% by mass solution in a 2 N sodium hydroxide solution, and the light transmittance of the diamine component is a transmittance at a wavelength of 400 nm and an optical path length of 1 cm as a 8% by mass solution in methanol, water, N,N-dimethylacetamide or acetic acid or hydrochloric acid solutions thereof.

13. The polyimide precursor according to claim 1 having a light transmittance of 40% or more at a wavelength of 400 nm and an optical path length of 1 cm as a 10% by mass solution in a solvent selected from N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethylsulfoxide and water.

14. A polyimide precursor solution composition comprising the polyimide precursor according to claim 1 dissolved in a solvent, wherein the solvent has a light transmittance of 89% or more at a wavelength of 400 nm and an optical path length of 1 cm.

15. A polyimide containing a repeating unit represented by the following chemical formula (5): ##STR00039## wherein A is a tetravalent group having a plurality of aliphatic six-membered rings and no aromatic ring in the chemical structure, with the proviso that the plurality of six-membered rings may have two common carbon atoms as constituents, and B is at least one selected from the group consisting of the following chemical formulae (4-1) to (4-3): ##STR00040## wherein Ar.sub.1, Ar.sub.2 and Ar.sub.3 are each independently a divalent group of benzene, biphenyl, terphenyl, naphthalene or anthracene, which may be substituted with C.sub.1-3 alkyl group, halogen group, nitro group, hydroxyl group or carboxylic group, and n1 is an integer of 0 to 5; ##STR00041## wherein Ar.sub.4, Ar.sub.5, Ar.sub.6, Ar.sub.7 and Ar.sub.8 are each independently a divalent group of benzene, biphenyl, terphenyl, naphthalene or anthracene, which may be substituted with C.sub.1-3 alkyl group, halogen group, nitro group, hydroxyl group or carboxylic group, and n2 is an integer of 0 to 5; ##STR00042## wherein Ar.sub.9, Ar.sub.10, Ar.sub.11, Ar.sub.12 and Ar.sub.13 are each independently a divalent group of benzene, biphenyl, terphenyl, naphthalene or anthracene, which may be substituted with C.sub.1-3 alkyl group, halogen group, nitro group, hydroxyl group or carboxylic group, and n3 is an integer of 0 to 5; or B is a divalent group having at least one chemical structure represented by the following chemical formula (2) in the chemical structure: ##STR00043##

16. The polyimide according to claim 15, wherein the six-membered rings in A have a crosslinked cyclic form, in which carbon atoms constituting the ring chemically bind to each other to form another ring.

17. The polyimide according to claim 15, wherein A is a group of the following chemical formula (3-2): ##STR00044## wherein R1 is a direct bond, a CH.sub.2 group, a C(CH.sub.3).sub.2 group, an SO.sub.2 group, an Si(CH.sub.3).sub.2 group, a C(CF.sub.3).sub.2 group, an oxygen atom or a sulfur atom.

18. The polyimide according to claim 15, wherein A is a group of the following chemical formula (3-4): ##STR00045## wherein R3 and R4 are each independently a CH.sub.2 group, a CH.sub.2CH.sub.2 group, an oxygen atom or a sulfur atom.

19. The polyimide according to claim 15, wherein B is at least one selected from the group consisting of the chemical formulae (4-1) to (4-3).

20. A polyimide obtained from the polyimide precursor according to claim 1.

21. The polyimide according to claim 15, wherein the total light transmittance (average transmittance of light having a wavelength 380 nm to 780 nm) of a film formed of the polyimide and having a thickness of 10 μm is 70% or more.

22. The polyimide according to claim 15, wherein the transmittance of light at a wavelength of 400 nm of a film formed of the polyimide and having a thickness of 10 μm is 50% or more.

23. The polyimide according to claim 15, wherein the average coefficient of linear thermal expansion from 50° C. to 200° C. of a film formed of the polyimide and having a thickness of 10 μm is 50 ppm/K or less.

24. The polyimide according to claim 15, wherein B in the chemical formula (5) is a divalent group having at least one chemical structure represented by the chemical formula (2) in the chemical structure; and the polyimide has an oxygen index of 22% (volume fraction) or more.

25. A substrate for a display, a touch panel or a solar battery formed of the polyimide according to claim 15.

26. A polyimide film/base material laminate comprising a polyimide film layer of the polyimide according to claim 15 on a base material.

27. The polyimide film/base material laminate according to claim 26, wherein the base material is at least one selected from the group consisting of ceramics, metals, and thermally-stable plastic films.

28. A flexible conductive substrate comprising a conductive layer of a conductive material formed on a polyimide film of the polyimide according to claim 15.

29. The flexible conductive substrate according to claim 28, wherein the conductive material is at least one selected from the group consisting of metals, metal oxides, conductive organic materials, and conductive carbon.

30. The flexible conductive substrate according to claim 28, wherein a gas-barrier layer and/or a light controlling layer is formed on the polyimide film surface.

31. A substrate comprising a circuit of a conductive layer on a surface of a polyimide film formed from the polyimide according to claim 15, optionally via a gas-barrier layer and/or an inorganic layer.

32. A flexible thin-film transistor comprising the substrate according to claim 31.

33. A liquid crystal device for a display device, EL device, or photoelectric device, comprising the substrate according to claim 31.

34. A process for producing a polyimide film/base material laminate or a polyimide film, comprising steps of: casting a polyimide precursor solution composition containing the polyimide precursor according to claim 1 and a solvent onto a base material; drying the composition to form a polyimide precursor film; and heating the polyimide precursor film at 350 to 500° C. for imidization on the base material, or in a state where the polyimide precursor film is peeled from the base material and fixed at the ends.

Description

EXAMPLES

(1) The present invention will now be described in more detail based on the following examples and comparative examples. However, the present invention is not limited to the following examples.

(2) In each of the following examples, evaluation was carried out based on the following methods.

(3) <Evaluation of Tetracarboxylic Component and Diamine Component>

(4) [Light Transmittance]

(5) As for tetracarboxylic components, a predetermined amount of tetracarboxylic components was dissolved in a solvent (2 N aqueous solution of sodium hydroxide) to obtain a 10 mass % solution. As for diamine components, a predetermined amount of diamine components was dissolved in a solvent (methanol) to obtain an 8 mass % solution. Using a MCPD-300 manufactured by Otsuka Electronics Co., Ltd., and a standard cell having a light path length of 1 cm, the light transmittance at 400 nm of the prepared solutions of the diamine components and the tetracarboxylic components was measured using the measurement solvent as a blank.

(6) <Evaluation of Solvent>

(7) [GC Analysis: Solvent Purity]

(8) The solvent purity was measured under the following conditions using a GC-2010 manufactured by Shimadzu Corporation. The purity (GC) was determined from the peak surface area fraction.

(9) Column: DB-FFAP manufactured by J&W, 0.53 mm ID×30 m

(10) Temperature: 40° C. (5 minutes holding)+40° C. to 250° C. (10 minutes/minutes)+250° C. (9 minutes holding)

(11) Inlet temperature: 240° C.

(12) Detector temperature: 260° C.

(13) Carrier gas: Helium (10 ml/minute)

(14) Injection amount: 1 μL

(15) [Non-Volatile Content]

(16) 5 g of solvent was weighed in a glass vessel and heated at 250° C. for 30 minutes in a hot air circulating oven. The vessel was cooled and the residual matter was weighed. From the mass of the residual matter, the non-volatile content (mass %) in the solvent is determined.

(17) [Light Transmittance and Light Transmittance after Heating with Refluxing]

(18) Using a MCPD-300 manufactured by Otsuka Electronics Co., Ltd., and a standard cell having a light path length of 1 cm, the light transmittance of a solvent at 400 nm was measured using water as a blank.

(19) As for light transmittance after heating with refluxing, light transmittance at 400 nm was measured for a solvent that had been heated to reflux for 3 hours under nitrogen atmosphere having oxygen concentration of 200 ppm or less.

(20) [Quantification of Metal Component]

(21) The metal content contained in the solvent was quantified based on inductively coupled plasma mass spectrometry (ICP-MS) using an Elan DRC II manufactured by PerkinElmer Inc.

(22) <Evaluation of Polyimide Precursor Solution Composition>

(23) [Concentration of Solid Content]

(24) One gram of polyimide precursor solution composition was weighed into an aluminum dish, heated for 2 hours in a 200° C. hot air circulating oven to remove the non-solid content. The concentration of solid content (mass %) was determined from the residual matter.

(25) [Rotational Viscosity]

(26) The viscosity of the polyimide precursor solution at a temperature of 25° C. and a shear rate of 20 sec.sup.−1 was determined using a TV-22 E-type rotary viscometer manufactured by Toki Sangyo Co., Ltd.

(27) [Logarithmic Viscosity]

(28) The logarithmic viscosity was determined by measuring a 0.5 g/dL solution of the polyimide precursor in N,N-dimethylacetamide at 30° C. using an Ubbelohde viscometer.

(29) [Light Transmittance]

(30) The polyimide precursor was diluted with N,N-dimethylacetamide so as to form a 10 mass % polyimide precursor solution. Then, using the prepared solutions and using a MCPD-300 manufactured by Otsuka Electronics Co., Ltd., and a standard cell having a light path length of 1 cm, the light transmittance at 400 nm of the 10 mass % polyimide precursor solution was measured using N,N-dimethylacetamide as a blank.

(31) <Evaluation of Polyimide Film>

(32) [Light Transmittance]

(33) The light transmittance at 400 nm and total light transmittance (average light transmittance from 380 nm to 780 nm) of a polyimide film with a thickness of 10 μm were measured using a MCPD-300 manufactured by Otsuka Electronics Co., Ltd.

(34) [Elastic Modulus and Elongation at Break]

(35) The initial elastic modulus and elongation at break for a chuck interval of 30 mm and a tension rate of 2 mm/min were measured using a Tensilon manufactured by Orientec Co., Ltd., on a test piece produced by punching a polyimide film with a thickness of 10 μm into an IEC450 standard dumbbell shape.

(36) [Coefficient of Thermal Expansion (CTE)]

(37) A test piece was produced by cutting a polyimide film with a thickness of 10 μm into a strip with a width of 4 mm. Then, using a TMA-50 manufactured by Shimadzu Corporation, the temperature of the test piece was increased to 300° C. at a rate of temperature increase of 20° C./min with a chuck interval of 15 mm and a load of 2 g. The average coefficient of thermal expansion from 50° C. to 200° C. was determined from the obtained TMA curve.

(38) [Bending Resistance]

(39) A test piece was produced by cutting a polyimide film with a thickness of 10 μm into a strip with a width of 4 mm. The test piece was bent with a curvature radius of 1 mm under the conditions of a temperature of 25° C. and a humidity of 50% RH. The resultant test pieces were visually observed. A test piece having no abnormality was indicated by ◯ (good) and a test piece having a crack was indicated by x (bad).

(40) [Solvent Resistance]

(41) A polyimide film having a thickness of about 10 μm was soaked in N,N-dimethylacetamide under the conditions of a temperature of 25° C. for one hour and thereafter, the state of the film was visually observed. A test piece having no abnormality was indicated by ◯ (good); a test piece having wrinkle or partly having a change of shape was indicated by Δ (medium), and a test piece dissolved or having a significant change of shape was indicated by x (bad).

(42) [5% Weight Loss Temperature]

(43) A polyimide film having a thickness of about 10 μm was used as a test piece. The temperature of the test piece was increased from 25° C. to 600° C. by use of a differential thermogravity/thermogravity simultaneous measuring apparatus (TG/DTA6300) manufactured by SII Nano Technology Inc., under a nitrogen flow at a temperature raising rate of 10° C./min. From the obtained weight curve, 5% weight loss temperature was obtained.

(44) [Oxygen Index]

(45) A polyimide film having a thickness of about 30 μm was used as a test piece. Oxygen index of the test piece was obtained by a method (test piece shape: V type, 140 mm×52 mm×about 30 μm) in accordance with JIS K 7201 using a candle combustion tester D-type manufactured by Toyo Seiki Seisaku-sho, Ltd.

(46) Abbreviation and purity and the like of the raw materials used in the respective following examples are as follows.

(47) [Diamine Component]

(48) DABAN: 4,4′-diaminobenzanilide; purity 99.90% (GC analysis).

(49) 4-APTP: N,N′-bis (4-aminophenyl)terephthalamide; purity 99.95% (GC analysis).

(50) ODA: 4,4′-oxydianiline; purity 99.9% (GC analysis).

(51) PPD: p-phenylene diamine purity 99.9% (GC analysis).

(52) TFMB: 2,2′-bis(trifluoromethyl)benzidine; purity 99.83% (GC analysis).

(53) BABA: N,N′-p-phenylene bis(p-aminobenzamide); purity 99% (GC analysis).

(54) AZDA: 2,4-bis (4-aminoanilino)-6-anilino-1,3,5-triazine; purity 99.9% (GC analysis).

(55) BABB: 1,4-Bis(4-aminobenzoyloxy)benzene; purity 99.8% (GC analysis).

(56) [Tetracarboxylic Acid Component]

(57) PMDA-HS: 1R,2S,4S,5R-Cyclohexane tetracarboxylic dianhydride; purity (as PMDA-HS) 92.7% (GC analysis); purity (as hydrogenated pyromellitic dianhydride) 99.9% (GC analysis).

(58) BPDA-H: 3,3′,4,4′-bicyclohexyltetracarboxylic dianhydride; purity (as mixture of stereoisomers) 99.9% (GC analysis).

(59) cis/cis-BTA-H: 1rC7-bicyclo[2.2.2]octane-2c,3c,5c,6c-tetracarboxylic-2,3:5,6-dianhydride; purity (as cis/cis-BTA-H) 99.9% (GC analysis).

(60) DNDAxx: (4arH,8acH)-decahydro-1t,4t:5c,8c-dimethano naphthalene-2t,3t,6c,7c-tetracarboxylic dianhydride; purity (as DNDAxx) 99.2% (GC analysis).

(61) DNDAdx: (4arH,8acH)-decahydro-1t,4t:5c,8c-dimethano naphthalene-2c,3c,6c,7c-tetracarboxylic dianhydride; purity (as DNDAdx) 99.7% (GC analysis).

(62) [Transmittance of Diamine and Acid Dianhydride]

(63) TABLE-US-00002 TABLE 2 Concen- 400 nm tration light trans- solvent (mass %) mittance (%) Diamine DABAN methanol 8 35 PPD methanol 8 61 TFMB methanol 8 99 acid cis/cis-BTA-H 2N NaOH 10 100 dianhydride DNDAxx 2N NaOH 10 70 DNDAdx 2N NaOH 10 100

(64) [Silylating Agent]

(65) BSA: N,O-bis(trimethylsilyl)acetamide

(66) [Solvent]

(67) DMAc: N, N-dimethylacetamide

(68) [Purity of Solvent (N, N-dimethylacetamide)]

(69) GC Analysis

(70) TABLE-US-00003 Retention time of main component (min) 14.28 Area of main component (%) 99.9929 Peak area of impurity having shorter retention time (%) 0.0000 Peak area of impurity having longer retention time (%) 0.0071 Non-volatile Content (mass %) <0.001

(71) Light Transmittance:

(72) TABLE-US-00004 Light transmittance at 400 nm (%) 92 Light transmittance at 400 nm after reflux (%) 92

(73) Metal Content:

(74) TABLE-US-00005 Na (ppb) 150 Fe (ppb) <2 Cu (ppb) <2 Mo (ppb) <1

(75) Table 3 shows the structural formulae of the tetracarboxylic acid components and diamine components used in Examples and Comparative examples.

(76) TABLE-US-00006 TABLE 3 Diamine component DABAN 0 4-APTP BABA AZDA TFMB PPD ODA Tetracarboxylic acid component PMDA-HS BPDA-H cis/cis-BTA-H DNDAxx 0 DNDAdx

Example 1

(77) In a reaction vessel purged with nitrogen gas, 2.27 g (10 mmol) of DABAN was charged and dissolved in 25.55 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 15% by mass and stirred at 50° C. for 2 hours. To the solution, 2.23 g (10 mmol) of PMDA-HS was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution.

(78) Measurement results of properties of the polyimide precursor solution are shown in Table 4-1.

(79) The polyimide precursor solution that was filtered using a PTFE membrane filter was applied on a glass substrate, and thermally imidized by heating at 120° C. for 1 hour, at 150° C. for 30 minutes, at 200° C. for 30 minutes, then heating up and at 350° C. for 5 minutes while holding it on the substrate under nitrogen atmosphere (oxygen concentration is 200 ppm or less) to obtain a colorless transparent polyimide/glass laminate. Thus obtained polyimide/glass laminate was immersed in water for delamination to obtain a polyimide film with thickness of about 10 μm.

(80) Measurement results of properties of the polyimide film are shown in Table 4-1.

Examples 2 to 51

(81) Polyimide precursor solutions and polyimide films were obtained in the same manner as Example 1 except that diamine component and carboxylic acid component were selected as indicated in Table 4-1, and N,N-dimethylacetamide is used in such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 15% by mass.

(82) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-1.

Example 6

(83) In a reaction vessel purged with nitrogen gas, 2.27 g (10 mmol) of DABAN was charged and dissolved in 21.16 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at 50° C. for 2 hours. To the solution, 2.11 g (7 mmol) of DNDAxx and 0.91 g (3 mmol) of DNDAdx were gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(84) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-1.

Example 7

(85) In a reaction vessel purged with nitrogen gas, 2.27 g (10 mmol) of DABAN was charged and dissolved in 21.16 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at 50° C. for 2 hours. To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(86) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-1.

Example 8

(87) In a reaction vessel purged with nitrogen gas, 2.27 g (10 mmol) of DABAN was charged and dissolved in 18.06 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at room temperature for 1 hour. To the solution, 4.07 g (20 mmol) of BSA was added and stirred at room temperature for 3 hours. To the solution, 2.24 g (10 mmol) of PMDA-HS was gradually added. The solution was stirred at room temperature for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(88) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-1.

Example 9

(89) In a reaction vessel purged with nitrogen gas, 2.05 g (9 mmol) of DABAN and 0.11 g (1 mmol) of PPD were charged and dissolved in 17.45 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at room temperature for 1 hour. To the solution, 2.24 g (10 mmol) of PMDA-HS was gradually added. The solution was stirred at room temperature for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(90) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-1.

Example 10

(91) In a reaction vessel purged with nitrogen gas, 2.05 g (9 mmol) of DABAN and 0.32 g (1 mmol) of TFMB were charged and dissolved in 18.04 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at room temperature for 1 hour. To the solution, 2.24 g (10 mmol) of PMDA-HS was gradually added. The solution was stirred at room temperature for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(92) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-1.

Example 11

(93) In a reaction vessel purged with nitrogen gas, 3.46 g (10 mmol) of 4-APTP was charged and dissolved in 25.29 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at 50° C. for 2 hours. To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(94) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-2.

Example 12

(95) In a reaction vessel purged with nitrogen gas, 2.27 g (10 mmol) of DABAN was charged and dissolved in 21.16 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at 50° C. for 2 hours. To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution. To the solution, 4.07 g (20 mmol) of BSA was added and stirred for 12 hours. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(96) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-2.

Example 13

(97) In a reaction vessel purged with nitrogen gas, 3.46 g (10 mmol) of 4-APTP was charged and dissolved in 36.72 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 15% by mass and stirred at 50° C. for 2 hours. To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution. To the solution, 2.03 g (10 mmol) of BSA was added and stirred for 12 hours. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(98) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-2.

Example 14

(99) In a reaction vessel purged with nitrogen gas, 1.59 g (7 mmol) of DABAN and 0.32 g (3 mmol) of PPD were charged and dissolved in 19.85 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at room temperature for 1 hour. To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at room temperature for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(100) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-2.

Example 15

(101) In a reaction vessel purged with nitrogen gas, 1.59 g (7 mmol) of DABAN and 0.96 g (3 mmol) of TFMB were charged and dissolved in 22.59 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at room temperature for 1 hour. To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at room temperature for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(102) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-2.

Example 16

(103) In a reaction vessel purged with nitrogen gas, 2.42 g (7 mmol) of 4-APTP and 0.32 g (3 mmol) of PPD were charged and dissolved in 21.79 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at room temperature for 1 hour. To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at room temperature for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(104) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-2.

Example 17

(105) In a reaction vessel purged with nitrogen gas, 1.59 g (7 mmol) of DABAN and 0.32 g (3 mmol) of PPD were charged and dissolved in 19.75 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at room temperature for 1 hour. To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at room temperature for 6 hours to obtain a uniform and viscous polyimide precursor solution. To the solution, 4.07 g (20 mmol) of BSA was added and stirred for 12 hours. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(106) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-2.

Example 18

(107) In a reaction vessel purged with nitrogen gas, 3.46 g (10 mmol) of BABA was charged and dissolved in 25.94 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at room temperature for 1 hour. To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at room temperature for 6 hours to obtain a uniform and viscous polyimide precursor solution. The formation of film was carried out as described in Example 1 to provide a polyimide film.

(108) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-2.

Comparative Examples 1 to 4

(109) Polyimide precursor solutions and polyimide films were obtained in the same manner as Example 1 except that diamine components and carboxylic acid components were selected as indicated in Table 4-2, and N,N-dimethylacetamide is used in such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 15% by mass for Comparative examples 1 and 2 and 20% by mass for Comparative examples 3 and 4.

(110) Measurement results of properties of the polyimide precursor solutions and polyimide films are shown in Table 4-2.

(111) TABLE-US-00007 TABLE 4-1 Example Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 10 Formulation of Polyimide Precursor (mol %) Tetracarboxylic PMDA-HS 100 100 100 100 100 acid component BPDA-H 100 cis/ 100 100 cisBTA-H DNDAdx 30 DNDAxx 70 100 Diamine DABAN 100 100 100 100 100 90 90 component 4-APTP 100 100 100 BABA PPD 10 TFMB 10 ODA Silylating agent BSA 200 Properties of Polyimide Precursor solution composition Concentration of Solid 14 14 14 14 17 21 20 17 20 20 Content (mass %) Rotational Viscosity (Pa sec) 0.4 39 42 26 0.7 2.9 7.7 0.4 13.1 20.9 Logarithmic Viscosity (dL/g) 0.6 1.58 1.62 1.37 0.44 0.5 0.58 0.4 0.9 0.8 Light Transmittance at 43 400 nm (%) Properties of Polyimide Film Light Transmittance at 84 60 80 52 88 74 78 71 82 83 400 nm (%) Whole Light Transmittance 88 86 86 82 88 86 88 73 87 85 (%) Elastic Modulus (Gpa) 4.4 5.7 3.9 5.8 4.6 3.3 4.0 4.0 3.9 3.7 Elongation at break (%) 35 18 71 4 3 9 4 39 39 32 CTE (ppm/K) 36 16 44 12 33 49 39 50 46 49 Bending Resistance ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solvent Resistance ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ 5% Weight Loss 439 432 468 476 509 515 523 444 453 438 Temperature (° C.)

(112) TABLE-US-00008 TABLE 4-2 Exam- Exam- Exam- Exam- Example Example Example Example ple ple ple ple Comp. Comp. Comp. Cornp. 11 12 13 14 15 16 17 18 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Formulation of Polyimide Precursor (mol %) Tetra- PMDA- 100 carboxylic HS acid BPDA-H component cis/ 100 cisBTA-H DNDAdx 100 DNDAxx 100 100 100 100 100 100 100 100 100 Diamine DABAN 100 70 70 70 component 4-APTP 100 100 70 BABA 100 PPD 30 30 30 TFMB 30 ODA 100 100 100 100 Silylating BSA 200 100 200 agent Properties of Polyimide Precursor solution composition Concentration of Solid 20 21 11 19 22 21 24 17 14 22 20 Content (mass %) Rotational Viscosity 141.0 7.4 1.1 2.9 4.0 1.3 49.5 27 0.3 2.4 3.5 (Pa sec) Logarithmic Viscosity 1.2 0.62 1.07 0.56 0.51 1.04 0.75 1.02 0.56 0.5 0.6 (dL/g) Light Transmittance 43 53 at 400 nm (%) Properties of Polyimide Film Light Transmittance 59 77 65 76 83 66 50 86 84 75 81 at 400 nm (%) Whole Light 87 90 89 89 92 90 61 89 88 87 88 Transmittance (%) Elastic Modulus (Gpa) 5.8 4.6 6.5 3.8 3.6 4.3 3.5 3.1 2.2 1.7 2 Elongation at break (%) 4 9 10 7 13 13 6 73 10 8 27 CTE (ppm/K) 22 22 15 44 41 32 24 41 51 52 54 64 Bending Resistance ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Solvent Resistance ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Δ ◯ Δ Δ 5% Weight Loss 515 514 508 515 506 514 507 522 467 502 504 502 Temperature (° C.) note: CTE: Coefficient of Linear Thermal Expansion

(113) As can be seen from the results shown in Table 4, Examples 1 to 18 according to the present invention in which diamines having amide bonds) are used have smaller coefficient of linear thermal expansion and excellent solvent resistance compared with Comparative Examples 1 to 4.

(114) In addition, in cases that a tetracarboxylic acid component having two six-membered ring structure is used (Example 3) or that a crosslinked cyclic type tetracarboxylic acid component in which carbon atoms constituting six-membered ring are chemically bonded to form another ring is used (Examples 4 and 5), the produced polyimides have higher 5% weight loss temperature and are therefore excellent in heat resistance compared with the case in which a tetracarboxylic acid component having one six-membered ring structure is used (Examples 1 and 2).

(115) In addition, in cases that a polyalicyclic/crosslinked cyclic type tetracarboxylic acid component such as DNDAxx and DNDAdx (Examples 6 and 7) is used, the produced polyimides have further higher 5% weight loss temperature and are therefore excellent in heat resistance, compared with the cases in which a tetracarboxylic acid component having two six-membered ring structure is used (Example 3) or that a crosslinked cyclic type tetracarboxylic acid component in which carbon atoms constituting six-membered ring are chemically bonded to form another ring is used (Examples 4 and 5).

(116) It can be seen that the use of silylating agent results in the increase in elongation at break or smaller coefficient of linear thermal expansion (Examples 8, 12, 13 and 17).

(117) As described, the polyimides obtained from the polyimide precursors of the present invention have excellent light transmittance and bending resistance, and furthermore low coefficient of linear thermal expansion and excellent solvent resistance in combination. Therefore, they are suitably used as a transparent substrate that is colorless and transparent and capable of forming a fine circuit for use in displays and the like.

Example 19

(118) In a reaction vessel purged with nitrogen gas, 3.84 g (10 mmol) of AZDA was charged and dissolved in 34.49 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 15% by mass and stirred at 50° C. for 2 hours.

(119) To the solution, 2.24 g (10 mmol) of PMDA-HS was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution.

(120) Measurement results of properties of the polyimide precursor solution are shown in Table 5.

(121) The polyimide precursor solution that was filtered using a PTFE membrane filter was applied on a glass substrate, and thermally imidized by heating at 120° C. for 1 hour, at 150° C. for 30 minutes, at 200° C. for 30 minutes, then heating up and at 350° C. for 5 minutes while holding it on the substrate under nitrogen atmosphere (oxygen concentration is 200 ppm or less) to obtain a colorless transparent polyimide/glass laminate. Thus obtained polyimide/glass laminate was immersed in water for delamination to obtain a polyimide film with thickness of about 10 μm.

(122) Measurement results of properties of the polyimide films are shown in Table 5.

Example 20

(123) In a reaction vessel purged with nitrogen gas, 3.84 g (10 mmol) of AZDA was charged and dissolved in 27.44 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at 50° C. for 2 hours.

(124) To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution.

(125) Measurement results of properties of the polyimide precursor solution and the polyimide film are shown in Table 5.

Example 21

(126) In a reaction vessel purged with nitrogen gas, 3.84 g (10 mmol) of AZDA was charged and dissolved in 27.44 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at 50° C. for 2 hours.

(127) To the solution, 3.02 g (10 mmol) of DNDAdx was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution.

(128) Measurement results of properties of the polyimide precursor solution and the polyimide film are shown in Table 5.

Comparative Example 5

(129) In a reaction vessel purged with nitrogen gas, 2.00 g (10 mmol) of ODA was charged and dissolved in 16.98 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at 50° C. for 2 hours.

(130) To the solution, 2.24 g (10 mmol) of PMDA-HS was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution.

(131) Measurement results of properties of the polyimide precursor solution and the polyimide film are shown in Table 5.

Comparative Example 6

(132) In a reaction vessel purged with nitrogen gas, 2.00 g (10 mmol) of ODA was charged and dissolved in 20.08 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at 50° C. for 2 hours.

(133) To the solution, 3.02 g (10 mmol) of DNDAxx was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution.

(134) Measurement results of properties of the polyimide precursor solution and the polyimide film are shown in Table 5.

Comparative Example 7

(135) In a reaction vessel purged with nitrogen gas, 2.00 g (10 mmol) of ODA was charged and dissolved in 20.08 g of N,N-dimethylacetamide such an amount that the feeding amount of monomers (total amount of diamine component and carboxylic acid component) is 20% by mass and stirred at 50° C. for 2 hours.

(136) To the solution, 3.02 g (10 mmol) of DNDAdx was gradually added. The solution was stirred at 50° C. for 6 hours to obtain a uniform and viscous polyimide precursor solution.

(137) Measurement results of properties of the polyimide precursor solution and the polyimide film are shown in Table 5.

(138) TABLE-US-00009 TABLE 5 Example 19 Example 20 Example 21 Comp. Ex. 5 Comp. Ex. 6 Comp. Ex. 7 Formulation of Polyimide Precursor (mol %) Tetracarboxylic acid PMDA-HS 100 100 component DNDAxx 100 100 DNDAdx 100 100 Diamine AZDA 100 100 100 component ODA 100 100 100 Properties of Polyimide Precursor solution composition Concentration of Solid Content 14 18.5 20.3 17 19.8 21.8 (mass %) Rotational Viscosity (Pa sec) 0.3 8.6 10.4 27.0 3.5 2.4 Logarithmic Viscosity (dL/g) 0.6 0.61 0.78 1.02 0.62 0.49 Light Transmittance at 400 nm (%) 52 Properties of Polyimide Film Light Transmittance at 400 nm (%) 76 77.522185 88 86 81 75 Whole Light Transmittance (%) 89 86.254705 91 88 88 87 Elastic Modulus (Gpa) 3.4 3.3 3.2 3.1 2 1.7 Elongation at break (%) 20 8.4 14.6 73 8 27 CTE (ppm/K) 42 49 50 51 64 54 Bending Resistance ◯ ◯ ◯ ◯ ◯ ◯ Solvent Resistance ◯ ◯ ◯ Δ Δ Δ 5% Weight Loss Temperature 492 487 480 467 502 504 (° C.) Oxygen Index (vol %) 24.4 21.6 note: CTE: Coefficient of Linear Thermal Expansion

(139) As can be seen from the results shown in Table 5, Examples 19 to 21 according to the present invention in which diamines having a chemical structure represented by formula (2) are used have smaller coefficient of linear thermal expansion and are excellent in solvent resistance, heat resistance and flame resistance (high oxygen index), compared with Comparative Examples 5 to 7.

(140) Also, it is found that the use of polyalicyclic/crosslinked cyclic type tetracarboxylic acid component results in increase in the transparency at 400 nm (Examples 20 and 21).

(141) Thus, the polyimides obtained from the polyimide precursors of the present invention have excellent light transmittance and bending resistance, and furthermore low coefficient of linear thermal expansion, excellent solvent resistance and flame resistance in combination. Therefore, they are suitably used as a transparent substrate that is colorless and transparent and capable of forming a fine circuit for use in displays and the like.

INDUSTRIAL APPLICABILITY

(142) According to the present invention, there is provided a polyimide having excellent properties such as transparency, bending resistance and high heat resistance in combination with an extremely low coefficient of linear thermal expansion and excellent solvent resistance, and a precursor thereof. Furthermore, according to the present invention, there is provided a polyimide having excellent properties such as transparency, bending resistance and high heat resistance in combination with an extremely low coefficient of linear thermal expansion, excellent solvent resistance and flame resistance, and a precursor thereof. The polyimide obtained from the polyimide precursor and the polyimide have high transparency and a low coefficient of linear thermal expansion allowing a fine circuit to be easily formed, and solvent resistance in combination.