CN104640907B

CN104640907B - Polyimides and its formed body

Info

Publication number: CN104640907B
Application number: CN201380048324.6A
Authority: CN
Inventors: 石井淳; 石井淳一; 长谷川匡俊
Original assignee: School Artificial Person Dong Bang University; Honshu Chemical Industry Co Ltd
Current assignee: School Artificial Person Dong Bang University; Honshu Chemical Industry Co Ltd
Priority date: 2012-09-19
Filing date: 2013-09-19
Publication date: 2019-03-22
Anticipated expiration: 2033-09-19
Also published as: KR20150056779A; KR102062939B1; JPWO2014046180A1; CN104640907A; JP6165153B2; WO2014046180A9; KR20190095556A; WO2014046180A1

Abstract

The issue of the present invention is to provide a kind of polyimides and preparation method thereof, the polyimides has the excellent transparency, solvent processability (excellent dissolubility and film formation property) when having both high-fire resistance and low coefficient of linear thermal expansion, and showing using agent of low hygroscopicity solvent.For this purpose, providing a kind of polyimides containing structural unit shown in following formula (1).Formula (1)In formula, R each independently represents the alkyl that hydrogen atom or carbon atom number are 1~6, but in 2 R with same phenyl ring ining conjunction at least 1 be alkyl.

Description

Polyimides and its formed body

Technical field

The present invention relates to polyimides.

Background technique

It is in the field of display such as liquid crystal display, organic electroluminescent (EL) display, electronic newspaper, preparation process Transparent electrode (ITO is formed on the glass substrate；Indium Tin Oxide), thin film transistor (TFT) (TFT；Thin-Film Transistor) electrodes and the electronic component such as.In order to form this class component, high-fire resistance and excellent dimensional stability (low line Thermal expansion coefficient) be it is required, therefore, be difficult to be applicable in the transparent material in addition to glass substrate in the prior art.

On the other hand, the requirement in recent years for the lightweight of this class display and flexibility improves, previous glass Substrate has been difficult to cope with.Therefore, the substrate as substitution glass substrate, more light weight, soft resin substrate attract attention.But Be, up to the present, not yet find to have both completely high transparency, dimensional stability, heat resistance that glass substrate has and The resin substrate of excellent processability.

As the material candidate to resin substrate, engineering plastics can be enumerated as.But in existing transparent engineering plastics, Polyether sulfone with maximum heat resistance, although its glass transition temperature (Tg) is 225 DEG C, it is high that there are coefficients of linear thermal expansion Problem.

On the other hand, as with high-fire resistance, excellent dimensional stability, mechanical strength, insulating properties and flexibility etc. The material of good characteristic has all aromatic polyimides.The all aromatic polyimides is mostly in aerospace material, heat proof material, electricity It is used in sub- material etc..

Such as it has been reported that, polyamides obtained by the tetracarboxylic acid dianhydride and diamines as shown in following formula (5) and (6) containing ester group Imines shows high-fire resistance and excellent dimensional stability (referring to patent document 1, patent document 2 and patent document 3 etc.).

But be the most of all aromatic polyimides indicated with this quasi-polyimide, due to intramolecular conjugation and Electric charge transfer interacts and colours by force between Intramolecular, so being difficult to realize the transparency same with glass.

Therefore, it is proposed to a kind of polyimides that the transparency for inhibiting Kapton coloring is high.For example, by poly- Fluorine atom (referring to non-patent literature 1 etc.) is imported in acid imide, and makes the diamine component and tetracarboxylic acid two that constitute polyimides One or both of anhydride component uses alicyclic compound, and inhibits intramolecular conjugation and electric charge transfer interaction, saturating to improve The method of bright property (referring to patent document 4, patent document 5 etc.).

But the polyimides for having imported fluorine atom gets higher coefficient of linear thermal expansion sometimes.For example, being employed as monomer 4,4'- (hexafluoroisopropyli,ene base) diphthalic anhydrides (hereinafter referred to as 6FDA) when, although improving Kapton The transparency, but its coefficient of linear thermal expansion value becomes very high, and necessary dimensional stability is lacked in the preparation process of equipment.Cause This, when the glass as the industrial field substitutes substrate and uses above-mentioned fluorinated polyimide, due in Kapton It is poor that big coefficient of linear thermal expansion is generated between the electrodes such as ITO, TFT of upper formation, electronic component and Kapton, and is occurred Removing, crack phenomenon, there are problems that so that the reliability of electronic equipment significantly reduces.

In addition, it is employed as the polyimides of the alicyclic compound of diamine component, for example, using 4,4'- di-2-ethylhexylphosphine oxide (ring Hexylamine) etc. bendabilities high ester ring type diamines when, although non-coloring, transparent Kapton can be obtained, exist and cause The problem of heat resistance reduces, coefficient of linear thermal expansion increases.On the other hand, it discloses and selects as ester ring type diamines with upright and outspoken The anti-form-1 of structure, 4- diaminocyclohexane are allowed to and 3,3', 4,4'- biphenyltetracarboxylic acid dianhydride (hereinafter referred to as BPDA) groups It closes, and prepares the polyimides with high transparency, high glass transition temperature (345 DEG C), low coefficient of linear thermal expansion (23ppm/K) The technology of film (referring to patent document 6).But the polyimides do not dissolve in organic solvent, thus there are solution processabilities not The disadvantage of foot.

As described above, previous most of polyimides do not dissolve in organic solvent, thus polyimides itself it is not easy to be processed at Type.For this purpose, usually by tetracarboxylic acid dianhydride and diamines in the aprotic polar solvents such as n-methyl-2-pyrrolidone (NMP) Reaction with same mole is carried out, and aggregates into the polyimide precursor (polyamic acid) of high polymerization degree, then the polyamic acid solution is existed Curtain coating is dried to polyamide acid film on substrate, later in 300 DEG C or more thermal dehydration closed loops (hot-imide), in this way Two-step method prepare Kapton.

But the hot-imide under high temperature is one of the main reason for colouring film, therefore is not only unsuitable for having height The purposes of transparent demand, and since the big reaction occurred in hot-imide is shunk, and residual occurs in the film and becomes Shape may cause film warpage.In addition, making film generate defect when hot-imide because of by-product water, holding because of bubble The problem of blushing easily occurs is also very worrying.

Therefore, in order to avoid the hot-imide under high temperature, the polyimides of solvent soluble is proposed (referring to patent text It offers 7).For example, 6FDA, 3,3', 4,4'- biphenyl sulfone tetracarboxylic acid dianhydrides etc. used as tetracarboxylic acid dianhydride, and as diamines The polyimides of the combination such as 1,3- bis- (3- amino-benzene oxygen) benzene, bis- [4- (3- amino-benzene oxygen) benzene] sulfones and synthesis, it is shown that To the solubility of amide solvent etc..Solvent-soluble polyimide it is common have isopropylidene, sulfone, ether, meta position combine etc. Warp architecture and using trifluoromethyl as the bulky substituent of representative hinders cohesion, the crystallization of polyimides chain as a result, Change, as a result, solvent molecule is made to become prone to intrusion polyimides interchain.

In addition, the side of the following polyimides for obtaining high polymerization degree can be used in order to prepare such soluble polyimide Method: carrying out reaction with same mole for tetracarboxylic acid dianhydride and diamines in high boiling solvent, will in the presence of the entrainers such as dimethylbenzene Solution is heated to the by-product water in 150 DEG C or more removing systems.Addition acetic anhydride/pyrrole in polyamic acid solution also can be used The cyclodehydrations reagent such as pyridine, does not heat and obtains the method (chemical imidization method) of polyimides.

But most of solvent-soluble polyimides, since coefficient of linear thermal expansion is very high, so not having as aobvious As the necessary low heat expansion (dimensional stability) of device substrate.In order to make coefficient of linear thermal expansion be lower, it is necessary to will gather Imido main chain is relative to pellicular front parallel orientation (face interior orientation), for this purpose, the linearity of polyimides main chain, outspoken nature are sufficient Enough height necessitate condition.Such MOLECULE DESIGN is opposite with the aforementioned MOLECULE DESIGN for the purpose of improving solvent soluble , so solvent soluble and low heat expansion and to deposit be extremely difficult project in principle.

As the example limited to for having both above-mentioned characteristic, there is report following (referring to patent document 8): high with linearity BPDA, pyromellitic acid anhydride (hereinafter referred to as PMDA) and bis- (trifluoromethyl) benzidine (hereinafter referred to as TFMB) of 2,2'- are The polyimides of primary raw material synthesis, only the display dissolution in amide solvent n-methyl-2-pyrrolidone (hereinafter referred to as NMP) Property, and lower coefficient of linear thermal expansion is shown by the cast membrane that the nmp solution is formed.

As described above, most of soluble polyimide is only solvable in the amide solvents such as the strong NMP of dissolving power, molten It is almost insoluble in Xie Li weak non-amide solvent especially agent of low hygroscopicity solvent.But the polyamides by being originated from amide solvent Imines varnish can usually generate significant problem when forming film.

That is, since the hygroscopicity of amide solvent is high, making polyimides sometimes when lasting longer continuous coating The moisture in atmosphere is absorbed, and causes the hole of apparatus for coating to block up by the precipitation of the tackifying of polyimide solution, polyimides Plug usually carrys out great obstacle to continuous coating zone.It is preferably molten to agent of low hygroscopicity as a result, from the viewpoint of solution processability Agent has the polyimides of highly dissoluble, still, up to the present not yet finds to be dissolvable in water lower than amide solvent polarity Low heat expansion polyimides in solvent.

As described above, making solution processability (agent of low hygroscopicity solvent soluble), low coefficient of linear thermal expansion, high heat resistance in the past Property, high transparency have both and the MOLECULE DESIGN of all aromatic polyimides that fully meets be it is extremely difficult, not yet found Full up foot is imaged as base-board of liquid crystal display, organic electroluminescent (EL) base plate for displaying, electronic newspaper substrate etc. It is physical property required by the transparent substrates such as device substrate and solar cell substrate, transparency protected membrane material, practical Transparent plastic substrate material.

Existing technical literature

Patent document

1 Japanese Unexamined Patent Publication 10-070157 bulletin of patent document

2 Japanese Unexamined Patent Publication 2006-013419 bulletin of patent document

Patent document No. 2008/09110 bulletin of 3 International Publication No.

4 Japanese Unexamined Patent Publication 07-56030 bulletin of patent document

5 Japanese Unexamined Patent Publication 09-73172 bulletin of patent document

6 Japanese Unexamined Patent Publication 2002-161136 bulletin of patent document

7 Japanese Unexamined Patent Publication 2002-206057 bulletin of patent document

8 Japanese Unexamined Patent Publication 2006-206756 bulletin of patent document

Non-patent literature

Non-patent literature 1:Macromolecules, 24,5001 (1991)

Summary of the invention

The purpose of the present invention, being to provide one kind has the excellent transparency, has both high-fire resistance and low coefficient of linear thermal expansion, and The polyimides of solvent processability (excellent dissolubility and film formation property) when showing using agent of low hygroscopicity solvent, and by its It is dissolved in agent of low hygroscopicity solvent and the polyimide varnish prepared and the thus obtained low line heat having both with inorganic thin film on an equal basis The coefficient of expansion, the film of high-fire resistance and high transparency and their preparation method.

The present inventor in order to solve the above problems, the result of sharp study, it was found that contain structure list shown in following formula (1) The polyimides of member, and find that the polyimides has the excellent transparency, have both high-fire resistance and low coefficient of linear thermal expansion, shows Solvent processability (excellent dissolubility and film formation property) when showing using agent of low hygroscopicity solvent, and can get be easily soluble in it is low The polyimide varnish of hygroscopicity solvent, in addition, also can get the Kapton with the excellent transparency, this completes The present invention.

The present invention is as follows:

1. a kind of polyimides, which is characterized in that contain structural unit shown in following formula (1).

Formula (1)

(in formula, the alkyl that R each independently represents hydrogen atom or carbon atom number is 1~6, but 2 in conjunction with same phenyl ring At least 1 is alkyl in a R.)

2. a kind of polyimides, which is characterized in that contain structural unit shown in following formula (2).

Formula (2)

3. the polyimides according to 1, which is characterized in that structure shown in the following formula (1) containing 70 moles of % or more Unit.

Formula (1)

4. a kind of polyimide varnish, which is characterized in that contain polyimides described in any one of 1~3 and organic molten Agent.

5. the polyimide varnish according to 4, which is characterized in that the organic solvent is molten selected from esters solvent, ethers Agent, carbonate-based solvent, glycol solvent, phenol solvent, agent of low hygroscopicity organic solvent at least one kind of in ketones solvent, and The solid component concentration of the polyimides is 5 mass % or more.

6. a kind of polyimides formed body, which is characterized in that contain structural unit shown in following formula (1).

Formula (1)

7. the polyimides formed body according to 6, which is characterized in that formed body is film.

8. a kind of Kapton, which is characterized in that be polyimide varnish described in 4 or 5 is coated on substrate, It dries and removes and be made from substrate.

9. according to Kapton described in 7 or 8, which is characterized in that when the film thickness of Kapton is 10 μm, Light transmission rate under 400nm is 45% or more, or when film thickness is 20 μm, full light transmission rate is 80% or more.

10. according to Kapton described in 7 or 8, which is characterized in that when the film thickness of Kapton is 10 μm When, the light transmission rate under 400nm is 45% or more, and when film thickness is 10 μm, full light transmission rate is 70% or more.

11. the synthetic method of polyimides of the one kind containing structural unit shown in following formula (1), which is characterized in that will gather Heating temperature is lower than 150 DEG C when amide precursor imidizate.

Formula (1)

Polyimides of the invention has 2 biphenylene structures combined in contraposition, therefore main chain in structural unit Structure becomes extremely linearity and upright and outspoken, and with this corresponding, the Kapton as made from the polyimides, shows as described above The low coefficient of linear thermal expansion and high-fire resistance (high glass transition temperature) same with inorganic thin film are shown.

Additionally, it is known that in this technical field, containing the high MOLECULE DESIGN to biphenylene structure of 2 linearity, meeting Significantly reduce solvent solubility.But polyimides of the invention, solvent solubility is excellent, and the transparency is also excellent.These Be considered as: there are methyl and fluoroform for the position 2,2' of the biphenylene of polyimides of the invention due to constituting polyimides Base, so making the sub- phenyl ring for constituting biphenylene distortion be difficult coplanarization by space steric effect, so that macromolecular chain Cohesion, it is electron conjugated be suppressed, and thus substantially increase the dissolubility of solvent, meanwhile, the polyamides as coloration reason is sub- The distinctive electric charge transfer interaction of amine is also suppressed, so improving the transparency.Additionally it is believed that 3 of biphenylene, 3' Position, 5 or/and 5' alkyl also contribute to same three-dimensional effect.

Foregoing polyimides of the invention dissolves in various solvents, especially with the agent of low hygroscopicity as solvent When solvent, resulting polyimide varnish shows high stability of solution, and therefore, application conditions when independent of film can Stabilization is processed into Kapton.In addition, resulting Kapton have both high-fire resistance possessed by the polyimides, Low coefficient of linear thermal expansion and high photopermeability (transparency), therefore, as base-board of liquid crystal display, organic electroluminescent (EL) the imagings transparent substrate such as base plate for displaying, electronic newspaper substrate, transparency protected membrane material and solar battery The transparent substrates such as substrate, transparency protected membrane material are useful.

Detailed description of the invention

Fig. 1 is the infrared absorption spectrum for the polyimides being made by embodiment 1

Fig. 2 is the infrared absorption spectrum of the polyimides as made from embodiment 5

Fig. 3 is the infrared absorption spectrum of the polyimides as made from embodiment 6

Specific embodiment

Polyimides of the invention is the polyimides containing structural unit shown in following formula (1).

Formula (1)

In formula, R each independently represents hydrogen atom or carbon atom number as 1~6 alkyl.But 2 in conjunction with same phenyl ring At least 1 is alkyl in a R.

In formula, when R is alkyl, the alkyl for the straight-chain, branched that carbon atom number is 1~6 is indicated, it is specific enumerable Are as follows: methyl, ethyl, isopropyl, n-propyl, tert-butyl, isobutyl group, n-hexyl, n-pentyl etc..It is preferred that carbon atom number is 1~4 Alkyl, more preferably methyl.Additionally, it is preferred that 2 R combined on same phenyl ring are alkyl.

Therefore, preferred polyimides is the polyimides containing structural unit shown in following formula (2).

Formula (2)

As previously mentioned, it is previous, in order to make polyimides or Kapton low thermal expansion, usually require to make as far as possible Backbone structure is linear, improves outspoken nature, inhibits the linear reduction of main chain with conformation change.But such molecule It is unfavorable for solvent solubility to design.

In this regard, polyimides of the invention, molten in order to improve while keeping main chain backbone as linear as possible and upright and outspoken Agent dissolubility, by import via ester group bonding make that 2 face angles substantially distort to biphenylene, and solve while realizing low Thermal expansivity and this extremely difficult problem of solvent solubility and high transparency.

Polyimides shown in formula (1) or formula (2) of the invention, is not particularly limited preparation method, such as can lead to It crosses tetracarboxylic acid dianhydride shown in following formula (3) and bis- (trifluoromethyl) benzidine of 2,2'- shown in the following formula (7) as diamines (hereinafter sometimes referred to simply as TFMB) reaction, the process that the polyamic acid containing structural unit shown in following formula (4) is made, then by gained Above-mentioned polyamic acid carry out imidizate process and prepare.

Formula (3)

(in formula, R each independently represents hydrogen atom or carbon atom number as 1~6 alkyl.But 2 in conjunction with same phenyl ring At least 1 is alkyl in a R.)

Formula (7)

Formula (4)

(in formula, R each independently represents hydrogen atom or carbon atom number as 1~6 alkyl.But 2 in conjunction with same phenyl ring At least 1 is alkyl in a R, and the binding site of ester group is meta or para position relative to amido bond.)

In addition, tetracarboxylic acid dianhydride shown in above formula (3), it can biphenyl -4,4'- glycols shown in following formula (8) and inclined benzene Three acids are obtained by well known esterification.

Formula (8)

About the preparation method of the polyimides of the invention, containing under when all methyl of R in above formula (1) For the polyimides of structural unit shown in formula (2), it is described in detail.In addition, even if when R is other alkyl or hydrogen Atomic time still can equally be prepared with the polyimides containing structural unit shown in formula (2).

Formula (2)

Polyimides shown in above-mentioned formula (2), can the preparation of the tetracarboxylic acid dianhydride shown in following formula (9).

Formula (9)

Glycol i.e. 2,2' shown in following formula (10), 3,3', 5,5'- pregnancy can be used in tetracarboxylic acid dianhydride shown in above formula (9) Base-biphenyl -4,4'- glycol (hereinafter sometimes referred to simply as HM44BP) or its diacetate body pass through known with trimellitic acid class Esterification and prepare.

Formula (10)

As trimellitic acid class, trimellitic anhydride, halogenation trimellitic anhydride etc. can be enumerated as.

Tetracarboxylic acid dianhydride shown in polyimides raw material according to the present invention, that is, above formula (9) is (hereinafter sometimes referred to simply as TAHMBP structure feature) is following two points: methyl substituents are incorporated on the position 2,2' of central biphenylene, so making Asia Xenyl significantly distorts, and connection biphenylene and 2 ester groups at phthalimide position are all combined in contraposition. Think so that heat resistance, agent of low hygroscopicity solvent solubility, the transparency and the same coefficient of linear thermal expansion of inorganic thin film can It realizes simultaneously.

When polymerizeing polyimide precursor (polyamic acid) according to the present invention, not significantly damage polymerisation reactivity with It, can also be by the aromatic series or rouge other than tetracarboxylic acid dianhydride shown in above formula (9) and in the range of characteristic required by polyimides Fat race tetracarboxylic acid dianhydride is used in combination as copolymer composition.

It as workable aromatic tetracarboxylic dianhydride in this case, is not particularly limited, such as can enumerate are as follows: equal benzene tetramethyl Acid dianhydride, 3,3', 4,4'- bibenzene tetracarboxylic dianhydride, hydroquinone-bis- (trimellitic anhydrides), bis- (the inclined benzene of methyl hydroquinone- Three acid anhydrides), 1,4,5,8 naphthalenetetracarboxylic acid dianhydride, 2,3,6,7- naphthalenetetracarbacidic acidic dianhydride, 3,3', 4,4'- benzophenone tetracarboxylic two Acid anhydride, 3,3', 4,4'- Biphenyl Ether tetracarboxylic acid dianhydride, 3,3', bis- (the 3,4- dicarboxyl benzene of 4,4'- biphenyl sulfone tetracarboxylic acid dianhydride, 2,2'- Base) hexafluoro propionic acid dianhydride, bis- (3,4- dicarboxyphenyi) the propionic acid dianhydrides of 2,2'- etc..

It as aliphatic tetracarboxylic acid dianhydride, is not particularly limited, such as ester ring type is enumerated are as follows: bicyclic [2.2.2] octyl- 7- Alkene -2,3,5,6- tetracarboxylic acid dianhydride, 5- (dioxotetrahydrofuryl -3- methyl -3- cyclohexene -1,2- dicarboxylic acid anhydride, 4- (2, 5- dioxotetrahydro furans -3- base)-naphthane -1,2- dicarboxylic acid anhydride, tetrahydrofuran -2,3,4,5- tetracarboxylic acid dianhydride, it is bicyclic - 3,3', 4,4'- tetracarboxylic acid dianhydride, 1,2,3,4- cyclobutanetetracarboxylic dianhydride, 1,2,3,4- cyclopentane tetracarboxylic acid dianhydride etc..Separately Outside, the above two or more can be used in combination.

In these tetracarboxylic acid dianhydrides, from the viewpoint of the low heat expansion of performance Kapton, preferably have rigid The tetracarboxylic acid dianhydride of straight linear structure, i.e., with pyromellitic acid anhydride, 3,3', 4,4'- bibenzene tetracarboxylic dianhydrides are as copolymerization Ingredient, from polymerisation reactivity and the angle being easy to get, particularly preferable as the 3,3' of tetracarboxylic acid dianhydride, 4,4'- biphenyl Tetracarboxylic acid dianhydride.

With the aromatic series of tetracarboxylic acid dianhydride shown in above formula (9) or the content range of aliphatic tetracarboxylic acid dianhydride For 0~30 mole of % of whole tetracarboxylic acid dianhydride usage amounts.

Polyimides according to the present invention containing structural unit shown in above formula (2), is by tetramethyl as described above Made from acid dianhydride is reacted with bis- (trifluoromethyl) benzidine (TFMB) of 2,2'-.

Therefore, in polyimides according to the present invention, since raw material diamines uses TFMB, and exist in TFMB 2,2' trifluoromethyls, so intermolecular active force reduces, so that the agent of low hygroscopicity solvent solubility of polyimides increases. Moreover, trifluoromethyl is also used as electron attractivity group to work, therefore the electric charge transfer phase interaction as coloration reason can be pressed down With to help to improve the transparency of Kapton.Additionally, it is believed that upright and outspoken in TFMB facilitates biphenylene Show the low heat expansion of polyimides.

When polymerizeing polyimide precursor (polyamic acid) of the present invention, not significantly damage polymerisation reactivity and In the range of characteristic required by polyimides, can using other than TFMB aromatic series or aliphatic diamine as copolymer composition and simultaneously With.

Workable aromatic diamine is not particularly limited in this case, such as can be enumerated are as follows: p-phenylenediamine, m- benzene two Amine, 2,4 di amino toluene, 2,5- diaminotoluene, 2,4- diamino dimethylbenzene, 2,4- diamino durol, 4,4'- bis- Aminodiphenylmethane, 4,4' methylene bis (2-aminotoluene), 4,4' methylene bis (2- ethyl aniline), 4,4'- methylene Base bis- (2,6- dimethylanilines), 4,4' methylene bis (2,6- diethylaniline), 4,4'- diamino-diphenyl ether, 3,4'- Diamino-diphenyl ether, 3,3'- diamino-diphenyl ether, 2,4'- diamino-diphenyl ether, 4,4'- diamino diphenyl sulfone, 3, 3'- diamino diphenyl sulfone, 4,4'- diaminobenzophenone, 3,3'- diaminobenzophenone, 4,4'- diamino benzoyl replace Aniline, 4- aminophenyl -4'- Aminobenzoate, benzidine, 3,3'- dihydroxybiphenyl amine, 3,3'- dimethoxy benzidine, Bis- (4- amino-benzene oxygen) benzene of ortho-tolidine, m- tolidine, 1,4-, bis- (4- amino-benzene oxygen) benzene of 1,3-, 1,3- are bis- Bis- (4- amino-benzene oxygen) biphenyl of (3- amino-benzene oxygen) benzene, 4,4'-, bis- (4- (3- amino-benzene oxygen) benzene) sulfones, bis- (4- (4- Amino-benzene oxygen) benzene) sulfone, bis- (4- (4- amino-benzene oxygen) benzene) propane of 2,2-, bis- (4- (4- amino-benzene oxygen) benzene) six of 2,2- Bis- (4- aminophenyl) hexafluoropropane of fluoro-propane, 2,2-, p- triphenyl diamine etc..

In addition, as aliphatic diamine being chain fatty race or ester ring type diamines, as ester ring type diamines without special limit It is fixed, such as can enumerate are as follows: 4,4'- di-2-ethylhexylphosphine oxides (cyclohexylamine), isophorone diamine, anti-form-1, it is 4- diaminocyclohexane, suitable Formula -1,4- diaminocyclohexane, 1,4- hexamethylene bis- (methylamines), bicyclic (2.2.1) heptane of 2,5- bis- (amino methyls), 2,6- are bis- (amino methyl) bicyclic (2.2.1) heptane, bis- (amino methyl) tricyclic (5.2.1.0) decane of 3,8-, 1,3- diamino adamantane, 2,2- bis- (4- aminocyclohexyl) propane, bis- (4- aminocyclohexyl) hexafluoropropane of 2,2-, as chain fatty race diamines without spy It does not limit, such as 1,3- propane diamine, Putriscine, 1,5- pentanediamine, 1,6- hexamethylene diamine, 1,7- heptamethylene diamine, 1 can be enumerated as, 8- octamethylenediamine, 1,9-nonamethylene diamine, diamino radical siloxane etc..In addition, two or more in them can be used in combination.In this case, on The content range for stating diamines is 0-30 moles of % of whole diamines usage amounts.

When polymerizeing polyimide precursor (polyamic acid) according to the present invention, as used solvent, preferably N, The aprotics such as dinethylformamide, DMAC N,N' dimethyl acetamide, n-methyl-2-pyrrolidone, dimethyl sulfoxide are molten Agent, but as long as being any solvent that can dissolve the polyimides of polyimide precursor and imidizate of starting monomer and generation, It can use without doubt, the structure of these solvents is not particularly limited.

Specifically, following solvent for example can be used: n,N-Dimethylformamide, n,N-dimethylacetamide, N- methyl -2- The amide solvents such as pyrrolidones, gamma-butyrolacton, gamma-valerolactone, δ-valerolactone, γ-hexalactone, 6-caprolactone, Alpha-Methyl-γ- The esters solvents such as butyrolactone, butyl acetate, ethyl acetate, isobutyl acetate, the carbonates such as ethylene carbonate, propene carbonate Solvent, the glycol solvents such as diethylene glycol dimethyl ether, triethylene glycol, triethylene glycol dimethyl ether, phenol, m-cresol, p- first The phenols solvents such as phenol, o-cresol, 3- chlorophenol, 4- chlorophenol, cyclopentanone, cyclohexanone, acetone, methyl ethyl ketone, diisobutyl ketone, The ketones solvents such as methyl iso-butyl ketone (MIBK), tetrahydrofuran, Isosorbide-5-Nitrae-dioxane, dimethoxy-ethane, diethoxyethane, dibutyl The ether solvents such as ether, as other general solvents, it is possible to use: acetophenone, 1,3- dimethyl -2- imidazolidinone, sulfolane, two First sulfoxide, propylene glycol methyl ether acetate, glycol-ether, ethylene glycol-ether, 2- ethylene glycol monomethyl ether acetate, ethylene glycol ethyl ether Acetic acid esters, butyl glycol ether acetic acid esters, butanol, ethyl alcohol, dimethylbenzene, toluene, chlorobenzene, rosin, Mineral spirits, petroleum naphtha class are molten Two or more in them can also be used in mixed way by agent etc..

Polyimides is obtained by the way that tetracarboxylic acid dianhydride (TAHMBP) shown in formula (9) and (TFMB) are carried out polyaddition reaction After precursor, then by its imidizate, exceedingly useful polyimides of the invention in the industry can get.

Polyimides of the invention is from the linearity of macromolecular chain, outspoken nature, substituent group appropriate and spatial warping It is can have to have both solution processability (agent of low hygroscopicity solvent is molten when as polyimide resin for chemical structure characteristic Solution property), cannot obtain with low coefficient of linear thermal expansion, high-fire resistance and high transparency these the previous materials of inorganic thin film on an equal basis The material of the physical property obtained.

In general, the polymerisation reactivity of tetracarboxylic acid dianhydride and diamines can come to the malleable band of the Kapton finally obtained Significant impact.When polymerisation reactivity is not high enough, high condensate cannot be obtained, result reduces twining between polymer chain Around, it is thus possible to Kapton can be made to become fragile.At this point, since the TAHMBP used and TFMB of the invention is shown Sufficiently high polymerisation reactivity, so such worry is not present.

The method of synthesis of polyimides of the present invention is not particularly limited, and can suitably use well known method.Specifically, example It can such as synthesize by the following method.As the process for obtaining polyimide precursor (polyamic acid), firstly, in the reaction vessel will TFMB is dissolved in polymer solvent, be then slowly added into the solution with the substantially equimolar TAHMBP powder of TFMB, with machinery Blender etc. is at 0~100 DEG C, in preferably 20~60 DEG C of temperature ranges, stirs 0.5~150 hour, preferably 1~48 hour.

The concentration range of starting monomer is usually 5~50 weight % at this time, and preferred scope is 10~40 weight %.By Polymerization reaction is carried out within the scope of such monomer concentration, can get uniform, high polymerization degree polyimide precursor (polyamide Acid).The degree of polymerization of polyimide precursor is excessively increased, and when polymeric solution being made to be difficult to stir, can suitably be carried out with same solvent dilute It releases.From the toughness viewpoint of Kapton, it is desirable to which the degree of polymerization of polyimide precursor is high as far as possible.By above-mentioned It is polymerize within the scope of monomer concentration, it can be ensured that the degree of polymerization of polymer is sufficiently high, also can be sufficiently ensured starting monomer and its life At polymer dissolubility.

When being polymerize under the concentration lower than above range, the degree of polymerization of polyimide precursor cannot reach enough sometimes Height, in addition, be higher than polymerize within the scope of above-mentioned monomer concentration when, the dissolution of the polymer of monomer and its generation is sometimes not Sufficiently.In addition, can usually cause the formation of salt in polymerization initial stage when using aliphatic diamine, polymerization is interfered, so, in order to It improves the degree of polymerization as far as possible while inhibiting the formation of salt, preferably controls monomer concentration when polymerizeing above-mentioned appropriate dense It spends in range.

Then, it continues to explain the process of gained polyimide precursor (polyamic acid) imidizate.To obtain the present invention Heat dehydration closed loop hot-imide method can be used, with de- in the imidizate method of polyimide precursor for the purpose of polyimides The known methods such as the chemical imidization method of aqua.

However, it is preferred to the imidizate under not needing the such temperate condition of chemical imidization method of high-temperature heat treatment.Change The method other than imidizate, such as hot-imide method are learned, tetracarboxylic acid dianhydride and diamines are carried out in high boiling solvent etc. Molar reactive, is then heated to 150 DEG C or more in the presence of the entrainers such as dimethylbenzene, and by-product water in removing system can obtain The polyimides of the high polymerization degree of solution state is obtained, still, when being heated to 150 DEG C or more, sometimes colours solvent etc., these Coloring components can become the coloration reason of film, so such methods are not preferred.

That is, the imidizate method of polyimide precursor (polyamic acid) of the present invention, specifically, can enumerate Are as follows: by aforementioned resulting polyimide precursor solution, is prepared with solvent identical with the solvent used when polymerizeing and be easy stirring Polyimide precursor solution with appropriate solution viscosity, then with the equilateral stirring of mechanical agitator, organic acid anhydride and work is added dropwise in side For the dehydration closed-loop agent (chemical imidization agent) of basic catalyst being made of tertiary amine, and at 0~100 DEG C, preferably 10~ It at a temperature of 50 DEG C, stirs 1~72 hour, thus completes the imidizate of chemistry.

It is not particularly limited as organic acid anhydride workable in the case, acetic anhydride, propionic andydride etc. can be enumerated as.From examination The angle for being easily processed and refining of agent is set out, it is preferable to use acetic anhydride.In addition, pyridine, three can be used as basic catalyst Ethamine, quinoline etc., from reagent be easily handled and isolated angle, more preferably use pyridine, but it is not limited to this.Chemistry The content range of organic acid anhydride in acid imide agent is 1~10 times mole of polyimide precursor theory dehydrating amount, more preferably It is 1~5 times mole.In addition, the content range of basic catalyst is 0.1~2 times mole relative to the content of organic acid anhydride, it is more excellent Selecting range is 0.1~1 times mole.

In addition, in reaction solution after afore mentioned chemical imidizate, due to being mixed into chemical imidization agent and carboxylic acid etc. By-product (hereinafter referred to as impurity), it is therefore desirable to remove it and refine polyimides.Known method can be used in purification.For example, As the simplest method, it can be used and the reaction solution of imidizate is added dropwise in a large amount of poor solvent while stirring And polyimides is precipitated, polyimide powder is recycled later, washing is repeated, is dried under reduced pressure, is removed until by impurity, from And the method for obtaining polyimide powder.

At this point, as workable solvent, as long as polyimides is made to be precipitated, can efficiently remove impurity, be easily dried Solvent is just not particularly limited, such as the alcohols such as preferred water or methanol, ethyl alcohol, isopropanol, can also use them with.To bad molten The concentration of polyimide solution when being added dropwise in agent and being allowed to be precipitated can make the polyimides being precipitated become a block when excessively high, and There is a possibility that impurity residual in the coarse particle, and gained polyimide powder can may also be made to need when being dissolved in solvent It will be for a long time.

On the other hand, when the concentration of polyimide solution is excessively dilute, a large amount of poor solvent is needed, thus due to liquid waste processing Increase environmental pressure, get higher processing cost, therefore not preferably.So polyimide solution when being added dropwise into poor solvent Concentration be 20 weight % hereinafter, more preferable 10 weight % or less.At this moment the amount of used poor solvent is preferably polyamides Asia It is more than the equivalent of amine aqueous solution, more preferably 1.5~3 times amounts.Gained polyimide powder is recycled, with vacuum drying, hot air drying Dry wait removes residual solvent.Drying temperature and time, as long as not making polyimides rotten and decomposing residual solvent Temperature, then without limitation, preferably in for 30~200 DEG C of temperature ranges, dry 48 hours or less.

Polyimides of the invention can be selected suitably depending on the application as its inherent viscosity, is not particularly limited, such as conduct Kapton is in use, the preferred model of inherent viscosity from toughness and the operational viewpoint of solution, as polyimides It encloses for 0.1~10.0dL/g, more preferable range is 0.5~5.0dL/g.

In addition, tetracarboxylic acid dianhydride and/or sheet when reaction other than use raw material tetracarboxylic acid dianhydride according to the present invention Diamine component other than raw material diamines involved in inventing synthesizes according to the present invention containing knot shown in formula (1) or formula (2) In the case where the polyimides copolymer of structure unit, structure list shown in the formula (1) or formula (2) of 70 moles of % or more is preferably comprised The polyimides copolymer of member.

In addition, the dissolubility of polyimides of the invention in a solvent is excellent, so various organic solvents can be dissolved in, and Prepare polyimide varnish.In addition, resulting varnish for example can be used as the formed bodies such as Kapton and layered product and use.

Further, since polyimides of the invention is generally obtained with powder, so can also be at as resin itself Shape can be used as electronic component, plug, film, layered product according to its purpose by using appropriate, well known manufacturing process It is used etc. various formed bodies.

Polyimides of the invention is dissolved in organic solvent as varnish in use, as organic solvent, may be selected The adaptable solvent with the usage of varnish, processing conditions.For example, when lasting longer continuous coating, due to polyimides The moisture in solvent absorption atmosphere in solution, may be precipitated polyimides, it is advantageous to use triethylene glycol dimethyl ether, The agent of low hygroscopicity solvent such as gamma-butyrolacton or cyclopentanone.Thus, each of display agent of low hygroscopicity may be selected in polyimides of the invention Kind solvent, mixed solvent.

Used agent of low hygroscopicity solvent is not particularly limited, such as in usable gamma-butyrolacton, gamma-valerolactone, δ-penta The esters such as ester, γ-hexalactone, 6-caprolactone, Alpha-Methyl-gamma-butyrolacton, butyl acetate, ethyl acetate, isobutyl acetate are molten Agent, the carbonate-based solvents such as ethylene carbonate, propene carbonate, diethylene glycol dimethyl ether, triethylene glycol, triethylene glycol dimethyl ether Equal glycol solvents, the phenols solvents such as phenol, m-cresol, p-Cresol, o-cresol, 3- chlorophenol, 4- chlorophenol, ring The ketones solvents such as pentanone, cyclohexanone, acetone, methyl ethyl ketone, diisobutyl ketone, methyl iso-butyl ketone (MIBK), tetrahydrofuran, Isosorbide-5-Nitrae-dioxy oneself The ether solvents such as ring, dimethoxy-ethane, diethoxyethane, dibutyl ethers, as other general solvents, it is possible to use: benzene Ethyl ketone, 1,3- dimethyl -2- imidazolidinone, sulfolane, dimethyl sulfoxide, propylene glycol methyl ether acetate, glycol-ether, second two Alcohol-butyl ether, 2- ethylene glycol monomethyl ether acetate, ethyl cellosolve acetate, butyl glycol ether acetic acid esters, chloroform, butanol, ethyl alcohol, Dimethylbenzene, toluene, chlorobenzene, rosin, Mineral spirits, petroleum naphtha class solvent etc. can also make the mixing of two or more in them With.Even in addition, hygroscopicity solvent n,N-Dimethylformamide, n,N-dimethylacetamide, n-methyl-2-pyrrolidone etc. Amide solution by with above-mentioned agent of low hygroscopicity solvent combination, also can inhibit the precipitation of polyimides.

Next, to polyimide varnish according to the present invention and being allowed to Kapton prepared by forming Preparation method is described in more detail.

It, can basis as its solid component concentration when polyimides of the invention being dissolved in solvent and preparing varnish The purposes of varnish and suitably select, be not specially limited.Such as when doing film, according to the molecular weight of polyimides, preparation method And the film thickness of preparation, being preferably made solid component concentration is 5 weight % or more.When solid component concentration is too low, it is difficult to be formed The film of abundant film thickness, opposite, when solid component concentration is too dense, then solution viscosity is excessively high, and coating may be made to become difficult. As method when polyimides of the invention to be dissolved in solvent, for example, can be added while stirring solvent of the invention Polyimide powder, in air or inert gas, within the scope of the temperature below room temperature~solvent boiling point, dissolution 1 hour~ 48 hours, and prepare polyimide solution.

As the most preferred form for preparing film using polyimides of the invention, such as can be in supports such as glass substrates On, polyimide varnish is used into well known method, such as with drying after the coating such as spreading knife, so that it is thin to prepare polyimides Film.The coefficient of linear thermal expansion of thus obtained Kapton is preferably 30ppm/K hereinafter, more preferably 25ppm/K or less. In addition, the glass transition temperature as Heat-tolerant index, preferably 250 DEG C or more, it is contemplated that the film item of the inorganic thin films such as ITO Part, more preferably 270 DEG C or more.

About the transparency of Kapton of the invention, the full light transmission rate preferably when film thickness is 20 μm is 80% or more, more preferably 85% or more.

Additionally, it is preferred that the light transmission rate of 400nm when film thickness is 10 μm is 45% or more, more preferably 50% or more, into One step is preferably 60% or more, and particularly preferably 80% or more, further, as making the more excellent reason of the transparency, It is preferred that full light transmission rate when film thickness is 10 μm is 70% or more, more preferably 80% or more, further preferably 85% or more.

It should be noted that the preferred scope of the transmitance of 400nm, full light when film thickness described herein is 10 μm and 20 μm, It, can also be by the transmitance of its film thickness according to Lambert-Beer law even if film thickness is not the Kapton of 10 μm or 20 μm Etc. the transmitance being converted into when film thickness is 10 μm or 20 μm, in addition, when film thickness being processed into 10 μm or 20 μm and being measured Transmitance, as long as falling into above-mentioned preferred scope, Kapton in this case is also included within interior.

As long as in addition, the Kapton of same quality, since the transmitance of the more thin then film of film thickness is better, so The Kapton thicker than the film thickness of 10 μm or 20 μm need not when transmitance is within the scope of aforementioned preferred transmitance Conversion and measurement, are also contained in preferred Kapton.

As conversion method, such as the Kapton that the film thickness described below as made from embodiment 2 is 21 μm The transmitance of 400nm light be 69.5%, it is assumed that the product of molar absorption coefficient and concentration be it is certain, by its foundation Lambert-ratio That law, scaled value when calculating 10 μm are 84.0%.

In addition, it is even that release agent, filler, silane can be added as needed in polyimide varnish according to the present invention The additives such as mixture, crosslinking agent, end-capping reagent, antioxidant, defoaming agent, levelling agent.

Kapton can be formed with known method film, drying using resulting polyimide varnish.For example, logical It crosses and is cast polyimide varnish with spreading knife etc. on the supports such as glass substrate, reusable heat wind drier, infrared drying Furnace, vacuum desiccator, Inert Gas Ovens etc., it is dry usually within the scope of 40~300 DEG C of ranges, preferably 50~250 DEG C, it can Form Kapton.

Embodiment

The present invention is illustrated by the following examples, but is not limited to these embodiments.It should be noted that in following instance Physics value is measured by following methods.

(evaluation method)

Material property value described in this specification etc. is obtained by following evaluation method.

Using fourier-transform infrared spectrophotometer FT/IR350 (Japan's light splitting corporation), tetramethyl is measured with KBr method The infrared absorption spectrum of acid dianhydride.In addition, the infrared absorption spectrum about polyimides, by preparing (about 5 μm of film sample It is thick) and measure.

<¹H-NMR spectrum >

With fourier transform NMR JNM-ECP400 (JEOL system), the tetracarboxylic acid dianhydride in deuterated dimethyl sulfoxide is measured And the polyimide powder of chemical imidization¹H-NMR spectrum.Four monosilanes of standard items.

The fusing point of tetracarboxylic acid dianhydride, with differential scanning calorimetric analysis device DSC3100 (Bruker AXS corporation), in nitrogen It is measured in atmosphere with 2 DEG C/min of heating rate.The high melting peakss of fusing point are more sharp, indicate that purity is higher.

The polyimide precursor solution of 0.5 weight % or pair of polyimide solution are measured at 30 DEG C with Ostwald viscosimeter Specific viscosity.Using the value as inherent viscosity.

9.9g shown in 0.1g polyimide powder and table 2 (1 weight % of solid component concentration) organic solvent is added to In sample cell, stirred 5 minutes with test tube mixer, visual confirmation dissolved state.As solvent can be used chloroform (CF), acetone, Tetrahydrofuran (THF), 1,4- dioxane (DOX), ethyl acetate, cyclopentanone (CPN), cyclohexanone (CHN), N, N- dimethyl methyl Amide (DMF), DMAC N,N' dimethyl acetamide (DMAc), n-methyl-2-pyrrolidone (NMP), m-cresol, dimethyl sulfoxide (DMSO), gamma-butyrolacton (GBL), triethylene glycol dimethyl ether (Tri-GL).Evaluation result indicates are as follows: is when dissolving at room temperature " ++ " keeps when uniformity being "+" after dissolving by heating and being cooled to room temperature, is " ± " when expanding/being partly dissolved, is when insoluble “-”。

9~13 weight % are made in the concentration of polyimide solution, the solution is added drop-wise on glass substrate by 2mL, later 24 hours are stood in the environment of relative humidity is 40%.The polyamides after polyimide solution and rigid dropwise addition after standing for 24 hours Imide liquor is compared, and unconverted state is expressed as "○", is precipitated polyimides and the state of solution albefaction is expressed as "×".If in the case where relative humidity is 40% environment, polyimide solution is still unchanged after 24 hours, then it represents for preparing polyamides Asia Coating when amine film is excellent.

With the thermo-mechanical analysis device (TMA4000) of Bruker AXS corporation, by Measurement of Dynamic Viscoelasticity, by frequency It is the glass transition temperature that loss peak under 5 DEG C/min finds out Kapton for 0.1Hz, heating rate.

The coefficient of linear thermal expansion of Kapton, with the TMA4000 (specimen size: wide of Bruker AXS corporation 5mm, long 15mm), it is cold after being temporarily warming up to 150 DEG C (heating up for the first time) with 5 DEG C/min using film thickness (μm) × 0.5g as loading But to 20 DEG C, then with 5 DEG C/min heating (second of heating), TMA curve when being heated up by second is calculated.Linear thermal expansion system Number is acquired with the average value between 100~200 DEG C.

< 5% weight reduces temperature: Td⁵>

With the thermogravimetric analyzer (TG-DTA2000) of Bruker AXS corporation, measure heating rate in air be 10 DEG C/ In the temperature-rise period of minute, the initial stage weight of Kapton (20 μ m-thick) reduces temperature when 5%.The higher expression heat of the value Stability is higher.

The transmitance of < polyimide film: T₄₀₀>

With the UV, visible light near infrared spectrometer (V-650) of Japan's light splitting corporation, Kapton (20 is measured μ m-thick) light transmission rate at 200-700nm, the index using the light transmission rate under 400nm wavelength as the transparency.In addition, The wavelength (cutoff wavelength) when transmitance is 0.5% or less can also be found out.

<birefringent: Δ n>

With love delay corporation Abbe refractometer (Abbe 1T, use sodium vapor lamp, wavelength 589nm) measurement it is thin with polyimides Film surface parallel direction (n_in) and vertical direction (film thickness direction) (n_out) refractive index, birefringent (Δ is found out by the difference of the refractive index N=n_in-n_out).Birefringence value is higher, it is meant that the degree of orientation is higher in the face of polymer chain.

The Kapton (20~30 μm of film thickness) that 24 hours are dried in vacuo at 50 DEG C is impregnated 24 in 24 DEG C of water Hour, remaining moisture is wiped completely with paper of showing on trial later, and water absorption rate (%) is found out by the increased degree of weight.Most of It is more low the more preferred with the value on the way.

< capacitivity: ε_opt>

It is delayed the Abbe refractometer (Abbe 1T) of corporation with love, according to the mean refractive index (n of Kapton_av= (2n_in+n_out)/3), pass through following formula: ε_cal=1.1 × n_av ²Calculate the capacitivity (ε of Kapton_opt)。

Implement to stretch with test film (3mm × 30mm) of the TENSILON UTM-2 (A&D corporation) to Kapton It tests (extension speed: 8mm/ minutes), spring rate is found out by the initial stage gradient of load-deformation curve, stretching when by film breaks Long rate finds out extension at break (%).The extension at break the high, means that the toughness of film is higher.In addition, when being broken by test film Stress acquires breaking strength.

The synthesis of tetracarboxylic acid dianhydride shown in formula (9)

(synthesis)

The synthesis of tetracarboxylic acid dianhydride (TAHMBP) shown in formula (9) is as follows.8.8493g is added in eggplant type flask (42.0mmol) chlorination trimellitic anhydride, be dissolved at room temperature 30mL dehydration tetrahydrofuran (THF) in, diaphragm seal and prepare Solution A (24.9 weight % of solute concentration).Then, in another flask by 5.4044g (20.0mmol) 2,2', 3,3', 5, 5'- hexamethyl-biphenyl -4,4'- glycol (HM44BP) is dissolved in (solute concentration 14.5 in 38mL dehydration THF at room temperature Weight %), wherein be added 3.9mL (48mmol) pyridine, diaphragm seal and prepare solution B.

It is cooling in ice bath, solution B is slowly added dropwise in solution A with syringe while stirring, is stirred at room temperature later It mixes 24 hours.After reaction, white depositions are filtered out, then is washed with THF and deionized water.The removal of pyridine hydrochloride, It is to add silver nitrate aqueous solution in washing lotion, is confirmed with not seeing white precipitate.The crude product of washing is recycled, at 150 DEG C Lower vacuum drying 12 hours.Gained crude product is yellowish white powder, and receipts amount is 6.1984g, yield 50.1%.

(purification)

Resulting crude product is refined by recrystallization.88mL gamma-butyrolacton is added in 5.9905g crude product (GBL), a late natural cooling is stood after dissolving by heating in 150 DEG C.The yellowish white powder of precipitation is filtered out into recycling, 180 It is dried in vacuo 12 hours at DEG C.The receipts amount of resulting yellowish white powder is 3.6974g, and recrystallization yield is 66.2%.Pass through The product for recrystallizing and refining confirmed with fourier-transform infrared spectrophotometer FT/IR350 (Japan's light splitting corporation) 1861cm^-1And 1772cm^-1The acid dianhydride C=O stretching vibration absorption band at place, in 1745cm^-1The ester group C=O stretching vibration at place is inhaled Take-up.In addition, with fourier transform NMR JNM-ECP400 (JEOL system) carry out proton NMR measurement as a result, it is possible to return Belong to (DMSO-d₆,δ,ppm):1.98(s,-CH₃,6H),2.08-2.15(m,-CH₃,12H),6.98(brs,ArH,2H),8.33 (d, J=7.9Hz, ArH, 2H), 8.71-8.76 (m, ArH, 4H) can then confirm that product is TAHMBP.In addition, by differential scanning When calorimeter DSC3100 (Bruker AXS corporation) measures fusing point, sharp melting peakss are shown at 309.4 DEG C, thus Can illustrate this product is high-purity.

The synthesis of tetracarboxylic acid dianhydride shown in formula (5)

(synthesis)

The synthesis of tetracarboxylic acid dianhydride (hereinafter referred to as TA44BP) shown in formula (5) is as follows.It is added in eggplant type flask 16.8457g (80.0mmol) chlorination trimellitic anhydride is dissolved in 71mL dehydration n,N-Dimethylformamide (DMF) at room temperature In, diaphragm seal and prepare solution A (20 weight % of solute concentration).Then, by 7.4483g (40.0mmol) in another flask 4,4'- xenols are dissolved in 32mL dehydration DMF (solute concentration is 20 weight %) at room temperature, and 19.3mL is added wherein (240mmol) pyridine, diaphragm seal and prepare solution B.It is cooling in ice bath, solution B is slowly dripped with syringe while stirring It is added in solution A, stirs 12 hours at room temperature later.After reaction, yellow mercury oxide is filtered out, then with DMF and go from Sub- water washing.Silver nitrate aqueous solution is added in washing lotion, confirms the removal of pyridine hydrochloride not see white precipitate.It will wash The crude product recycling washed, is dried in vacuo 12 hours at 180 DEG C.Gained crude product is yellow powder, and receipts amount is 9.6930g, is received Rate is 38.5%.

(purification)

Resulting crude product is refined by recrystallization.120mL gamma-butyrolacton is added in 7.9956g crude product (GBL), 12 hours natural coolings are stood after dissolving by heating.The yellow flat crystal of precipitation is recovered by filtration, it is true at 200 DEG C Sky is 12 hours dry.The receipts amount of resulting yellowish white powder is 6.3165g, and recrystallization yield is 79%.Pass through recrystallization The product of purification confirmed 1861cm by fourier-transform infrared spectrophotometer FT/IR350 (Japan's light splitting corporation)^-1And 1782cm^-1The acid dianhydride C=O stretching vibration absorption band at place, in 1730cm^-1The ester group C=O stretching vibration absorption band at place.Separately Outside, with fourier transform NMR JNM-ECP400 (JEOL system) carry out proton NMR measurement as a result, it is possible to belong to (DMSO- d₆,δ,ppm):7.52(d,ArH,4H),7.58(d,ArH,4H),8.51(d,ArH,2H),8.6(m,ArH,4H),8.71- 8.76 (m, ArH, 4H) can confirm that product is TA44BP.In addition, by differential scanning calorimeter DSC3100 (Bruker AXS company System) measurement fusing point when, by showing sharp melting peakss 326 DEG C at, this product can be illustrated for high-purity.

The synthesis of tetracarboxylic acid dianhydride shown in following formula (11)

Formula (11)

(synthesis)

The synthesis of tetracarboxylic acid dianhydride (TA23X-BP) shown in formula (11) is as follows.6.3207g is added in eggplant type flask (30.0170mmol) chlorination trimellitic anhydride, be dissolved at room temperature 13.0mL dehydration GBL in, diaphragm seal and prepare solution A.Then, by 2.4239g (10.0032mmol) 2,2', 3,3'- tetramethyls-biphenyl -4,4'- glycol in another flask (23X-BP) is dissolved at room temperature in 37.3mL dehydration GBL, and 4.85mL (59.9656mmol) pyridine, diaphragm are added wherein It seals and prepares solution B.

It is cooling in ice bath, solution B was added drop-wise in solution A through 20 minutes or so with syringe while stirring, Zhi Houyu One evening of stirring at room temperature.

After reaction, white depositions are filtered out, then be washed with deionized.It is water-soluble that silver nitrate is added in washing lotion Liquid confirms the removal of pyridine hydrochloride not see white precipitate.The crude product of washing is recycled, is dried in vacuo at 80 DEG C It 1 hour and is dried in vacuo 12 hours at 100 DEG C.Gained crude product is white powder, and receipts amount is 5.6107g, and yield is 95.0%.

(purification)

Resulting crude product is refined by recrystallization.210mLGBL is added in 3.6411g crude product, in 100 A late natural cooling is stood after dissolving by heating at DEG C.Precipitate is recovered by filtration, is dried in vacuo 12 hours at 160 DEG C.Institute The receipts amount of the white powder obtained is 2.8178g, and recrystallization yield is 77.3%.

The product refined by recrystallization measures the result of infrared absorption spectrum, it is thus identified that 1780cm^-1The acid dianhydride at place C=O stretching vibration absorption band, in 1741cm^-1The ester group C=O stretching vibration absorption band at place.In addition, carrying out proton NMR measurement As a result, it is possible to belong to (DMSO-d6, δ, ppm): 2.02 (s ,-CH3,6H), 2.17 (s ,-CH3,6H), 7.07-7.09 (d, J= 8.3Hz, ArH, 2H), 7.24-7.26 (d, J=8.2Hz, ArH, 2H), 8.31-8.33 (d, J=7.96Hz, ArH, 2H), 8.70-8.72 (dd, J=7.86Hz, 1.22Hz, ArH, 2H), 8.67 (s, ArH, 2H) can confirm that product is TA23X-BP.Separately Outside, when measuring fusing point by differential scanning calorimeter, by the sharp melting peakss of display 309.1 DEG C at, this product can be illustrated to be High-purity.

(polymerization of polyimide precursor)

Bis- (trifluoromethyl) benzidine (TFMB) of 0.9607g (3mmol) 2,2'- are dissolved in 11.3g dehydration N, N- diformazan In yl acetamide (DMAc).TAHMBP powder described in 1.8558g (3mmol) synthesis example 1 is slowly added in the solution, in room Temperature lower stirring 96 hours, polyimide precursor polyamic acid is made (solid component concentration is 20.0 weight %).Gained polyamide The inherent viscosity of acid is 1.84dL/g.

(chemical imidization reaction)

It is 10.0 weight % that resulting polyamic acid solution, which is diluted to solid component concentration with dehydration DMAc, later in room The mixed solution of 2.8mL (30mmol) acetic anhydride and 1.2mL (15mmol) pyridine is slowly added dropwise in wherein while stirring under temperature, It is stirred for after completion of dropwise addition 24 hours.Gained polyimide solution is slowly added dropwise in a large amount of methanol, keeps polyimides heavy It forms sediment.Gained white depositions are sufficiently washed with methanol, are dried in vacuo 12 hours at 160 DEG C.Gained threadiness polyimides Powder is 2.5130g.When by carrying out proton NMR measurement to the powder, distinctive COOH proton in polyamic acid is not observed (near δ 13ppm) and NHCO proton (near δ 11ppm), and the completion for illustrating chemical imidization to react.Gained polyamides is sub- The inherent viscosity of amine is 3.16dL/g, is macromolecule aggressiveness.

(preparation of polyimide solution and the film of Kapton)

Above-mentioned polyimide powder is re-dissolved in cyclopentanone (CPN) at room temperature, 11.4 weight %'s of preparation is uniform molten Liquid.The polyimide solution is cast on the glass substrate, it is 2 hours dry at 60 DEG C with hot-air drier.Thereafter, connect substrate It is heat-treated 1 hour in 250 DEG C in a vacuum together, after being cooled to room temperature, Kapton is removed from glass substrate.It should Kapton again in vacuum 250 DEG C be heat-treated 1 hour, to remove residual deformation.Gained Kapton is nothing Color is transparent.When measuring the mechanical property of the Kapton (32 μm of film thickness), the average elongation of 20 test bars is 10.7%, Maximum elongation is 20.0%, tensile elasticity rate 4.5GPa, breaking strength 0.19GPa.In addition, when measurement thermal characteristics, line heat The coefficient of expansion is 21.7ppm/K in 24 μm of film thickness of Kapton, and glass transition temperature is 272 DEG C, and 5% thermogravimetric is reduced Temperature is 437 DEG C (in air).In addition, being 2.80 by the capacitivity that the refractive index of Kapton calculates, water absorption rate is 0.04%.It is combined with other evaluation results and characteristic is listed in shown in table 1.In addition, evaluation is prepared as the poly- of 11.4 weight % with CPN When the sucting wet stability of imide solution, even if also having no that solution changes in the environment of 24 hours relative humidity 40%.Separately Outside, also excellent relative to the solvent solubility of various solvents and weak relative to the such dissolving power of CPN, GBL, Tri-GL Agent of low hygroscopicity solvent also shows excellent dissolubility.This is attributed to the careful MOLECULE DESIGN of polyimides of the present invention.Dissolubility Test result is as shown in table 2.In addition, the infrared absorption spectrum of Kapton is as shown in Figure 1.

(preparation of polyimide solution and the film of Kapton)

Gamma-butyrolacton (GBL) is used to be redissolved at room temperature the polyimide powder as made from 1 the method for embodiment, Prepare the solution of 9.9 weight %.The polyimide solution is cast on the glass substrate, it is dry at 80 DEG C with hot-air drier 2 hours.Thereafter, it is heat-treated 1 hour in 250 DEG C together with substrate, after being cooled to room temperature, is removed from glass substrate in a vacuum Kapton.By the Kapton again in vacuum 250 DEG C be heat-treated 1 hour, to remove residual deformation.Gained Kapton is colorless and transparent.When measuring the mechanical property of the Kapton (22 μm of film thickness), 20 test bars Average elongation is 7.1%, maximum elongation 9.0%, tensile elasticity rate 4.4GPa, breaking strength 0.18GPa.In addition, surveying When determining thermal characteristics, coefficient of linear thermal expansion is 25.1ppm/K in 23 μm of film thickness of Kapton, and glass transition temperature is 274 DEG C, it is 437 DEG C (in air) that 5% thermogravimetric, which reduces temperature,.In addition, the capacitivity calculated by the refractive index of Kapton It is 2.80, water absorption rate 0.05%.It is combined with other evaluation results and characteristic is listed in table 1.In addition, evaluation is prepared as 9.9 with GBL When the stability of the polyimide solution of weight %, even if also having no that solution becomes in the environment of 24 hours relative humidity 40% Change.

(preparation of polyimide solution and the film of Kapton)

Will the polyimide powder as made from 1 the method for embodiment, be re-dissolved in triethylene glycol dimethyl ether at room temperature (TriGL), the solution of 10 weight % is prepared.The polyimide solution is cast on the glass substrate, with hot-air drier 100 It is 2 hours dry at DEG C.Thereafter, it is heat-treated 1 hour in 250 DEG C in a vacuum together with substrate, after being cooled to room temperature, from glass base Kapton is removed on plate.By the Kapton again in vacuum 250 DEG C be heat-treated 1 hour, with remove residual Deformation.Gained Kapton is colorless and transparent.When measuring the mechanical property of the Kapton (30 μm of film thickness), 20 The average elongation of test bar is 10.2%, maximum elongation 25.5%, tensile elasticity rate 4.2GPa, and breaking strength is 0.18GPa.In addition, coefficient of linear thermal expansion is 25.7ppm/K in 23 μm of film thickness of Kapton when measurement thermal characteristics, Glass transition temperature is 280 DEG C.In addition, being 2.79 by the capacitivity that the refractive index of Kapton calculates, water absorption rate is inspection It surveys and limits following (< 0.01%).It is combined with other evaluation results and characteristic is listed in table 1.In addition, evaluation is prepared as 10 weights with TriGL When measuring the stability of the polyimide solution of %, even if also having no that solution changes in the environment of 24 hours relative humidity 40%.

(preparation of polyimide solution and the film of Kapton)

Will the polyimide powder as made from 1 the method for embodiment, be re-dissolved in tetrahydrofuran (THF) at room temperature, Prepare the solution of 11.5 weight %.In addition to solvent changes, prepared using method same as the method recorded in embodiment 1 poly- Imide membrane.Gained Kapton be it is colorless and transparent, coefficient of linear thermal expansion is in 12 μm of film thickness of Kapton For 22.3ppm/K.In addition, when the evaluation stability of the THF polyimide solution for being prepared as 11.5 weight %, even if small 24 When relative humidity 40% in the environment of, also have no solution change.

(polymerization of polyimide precursor)

0.9607g (3mmol) TFMB is dissolved in 14.3g dehydration DMAc.1.2990g is slowly added in the solution TAHMBP powder described in (2.1mmol) synthesis example 1 and 0.2648g (0.9mmol) 3,3', 4,4'- diphenyl tetracarboxylic acid dianhydride (BPDA) powder stirs 72 hours at room temperature, and polyamic acid is made (solid component concentration is 15 weight %).Gained polyamide The inherent viscosity of acid is 1.46dL/g.

(chemical imidization reaction)

It is 9.6 weight % that above-mentioned polyamic acid solution, which is diluted to solid component concentration with dehydration DMAc, later in room temperature Under the mixed solution of 2.8mL (30mmol) acetic anhydride and 1.2mL (15mmol) pyridine is slowly added dropwise in wherein while stirring, it After be stirred for 24 hours.Gained polyimide solution is added in a large amount of methanol and is precipitated.Gained threadiness white is heavy Starch is sufficiently washed with methanol, is dried in vacuo 12 hours at 160 DEG C.

When carrying out proton NMR measurement to the powder, due to not observing distinctive COOH proton (δ 13ppm in polyamic acid Near) and NHCO proton (near δ 11ppm), so the completion that chemical imidization can be illustrated to react.The spy of gained polyimides Property viscosity be 2.96dL/g.

(preparation of polyimide solution and the film of Kapton)

Above-mentioned polyimide powder is re-dissolved in cyclopentanone (CPN) at room temperature, prepares the solution of 12.5 weight %.It will The polyimide solution is cast on the glass substrate, 2 hours dry at 60 DEG C with hot-air drier.Thereafter, together with substrate It is heat-treated 1 hour in 250 DEG C in a vacuum, after being cooled to room temperature, Kapton is removed from glass substrate.

By the Kapton again in vacuum 250 DEG C be heat-treated 1 hour, to remove residual deformation.Gained polyamides Imines film is colorless and transparent.When measuring the mechanical property of the Kapton (25 μm of film thickness), 20 test bars are averaged Elongation is 11.2%, maximum elongation 17.7%, tensile elasticity rate 4.5GPa, breaking strength 0.19GPa.In addition, measurement When thermal characteristics, coefficient of linear thermal expansion is 22.5ppm/K, glass transition temperature 273 in 22 μm of film thickness of Kapton DEG C, it is 449 DEG C (in air) that 5% thermogravimetric, which reduces temperature,.

In addition, be 2.84 by the capacitivity that the refractive index of Kapton calculates, water absorption rate 0.05%.It is commented with other Characteristic is listed in table 1 by the combination of valence result.In addition, evaluation is prepared as the stability of the polyimide solution of 12.5 weight % with CPN When, even if also having no that solution changes in the environment of 24 hours relative humidity 40%.In addition, the solvent relative to various solvents Dissolubility is excellent, and the agent of low hygroscopicity solvent weak relative to the such dissolving power of CPN, GBL, Tri-GL also show it is excellent Dissolubility.Even if in general, BPDA is had in this way the monomer of upright and outspoken structure as copolymer composition in use, its usage amount seldom, It usually will also result in the sharply decline of the solvent solubility of polyimides, still, polyimides copolymer of the invention is still tieed up Hold excellent dissolubility.This is attributed to the careful MOLECULE DESIGN of polyimides of the present invention.Solubility test result such as 2 institute of table Show.In addition, the infrared absorption spectrum of polyimides copolymerization body thin film is as shown in Figure 2.

(polymerization of polyimide precursor)

0.32g (1mmol) TFMB is dissolved in 2.12g dehydration DMAc.0.59g (1mmol) is slowly added in the solution TA23X-BP powder described in synthesis example 3, at room temperature stir 72 hours, be made polyimide precursor polyamic acid (solid at Dividing concentration is 30 weight %).

The inherent viscosity of gained polyamic acid is 1.18dL/g.

(chemical imidization reaction)

It is 12.0 weight % that gained polyamic acid solution, which is diluted to solid component concentration with dehydration DMAc, later in room temperature Under the mixed solution of 1.0g (10mmol) acetic anhydride and 0.4mL (5mmol) pyridine is slowly added dropwise in wherein while stirring, be added dropwise After be stirred for 24 hours.Gained polyimide solution is slowly added dropwise in a large amount of methanol, polyimides is precipitated.Institute It obtains white depositions sufficiently to be washed with methanol, be dried in vacuo 12 hours at 100 DEG C.Gained polyimide powder is 0.819g. When carrying out proton NMR measurement to the powder, due to do not observe in polyamic acid distinctive COOH proton (near δ 13ppm) and NHCO proton (near δ 11ppm), so the completion that chemical imidization can be illustrated to react.The inherent viscosity of gained polyimides For 1.81dL/g.

(preparation of polyimide solution and the film of Kapton)

Above-mentioned polyimide powder is re-dissolved in cyclopentanone (CPN) at room temperature, 8.0 weight %'s of preparation is uniform molten Liquid.The polyimide solution is cast on the glass substrate, it is 2 hours dry at 60 DEG C with hot-air drier.Thereafter, connect substrate It is heat-treated 1 hour in 200 DEG C in a vacuum together, after being cooled to room temperature, Kapton is removed from glass substrate.It should Kapton again in vacuum 200 DEG C be heat-treated 1 hour, to remove residual deformation.If gained Kapton has Dry stain, but be colorless and transparent.When measuring the thermal characteristics of the Kapton, coefficient of linear thermal expansion is poly- at 28.6 μm of film thickness It is 15.5ppm/K in imide membrane, the glass transition temperature for the Kapton that 13.0 μm of film thickness is 211 DEG C, 5% thermogravimetric Reducing temperature is 437 DEG C (in air) in 20.0 μm of Kaptons.

In addition, the infrared absorption spectrum of Kapton is as shown in Figure 3.

(preparation of polyimide solution and the film of Kapton)

The polyimide powder as made from 1 the method for embodiment is re-dissolved in N, N'- dimethylacetamide at room temperature Amine (DMAc) prepares the solution of 11.1 weight %.In addition to solvent changes, polyamides is prepared using method similarly to Example 1 Imines film.Gained Kapton be it is colorless and transparent, coefficient of linear thermal expansion is in 15 μm of film thickness of Kapton 27.1ppm/K.In addition, when the evaluation stability of the DMAc polyimide solution for being prepared as 11.1 weight %, in 24 small phases In the environment of humidity 40%, polyimides is precipitated in solution gonorrhoea.This shows since DMAc hygroscopicity is high, so that at 24 hours Solution absorbs moisture in the environment of relative humidity 40%.

(preparation of polyimide solution and the film of Kapton)

The polyimide powder as made from 1 the method for embodiment is re-dissolved in N- methyl -2- pyrrolidines at room temperature Ketone (NMP) prepares the solution of 9.8 weight %.In addition to solvent changes, polyamides Asia is prepared using method similarly to Example 1 Amine film.Gained Kapton be it is colorless and transparent, coefficient of linear thermal expansion is in 17 μm of film thickness of Kapton 26.7ppm/K.In addition, when the evaluation stability of the NMP polyimide solution for being prepared as 9.8 weight %, it is opposite at 24 hours In the environment of humidity 40%, polyimides is precipitated in solution gonorrhoea.This result with reference example 1 is again due to the highly hygroscopic of NMP Property.

(polymerization of polyimide precursor)

The TFMB of 0.9607g (3mmol) is dissolved in 6.6g dehydration DMAc.1.8558g is slowly added in the solution (3mmol) TAHMBP powder (solid component concentration is 30.0 weight %), then adds dehydration DMAc, stirs 11 at room temperature Its (20.0 weight % of solid component concentration).The inherent viscosity of gained polyimide precursor (polyamic acid) is 1.26dL/g.

(film of polyimide precursor film and the preparation of Kapton)

Resulting polyamic acid solution is cast on the glass substrate, it is 2 hours dry at 60 DEG C with hot-air drier.Its Afterwards, together with substrate in a vacuum at 200 DEG C, 0.5 hour, then at 350 DEG C, 1 hour progress hot-imide.It is cooling To room temperature, Kapton is removed from glass substrate.320 DEG C of heat treatment in vacuum again by the Kapton 1 hour, to remove residual deformation.Gained Kapton is gonorrhoea.

The coefficient of linear thermal expansion of the Kapton is 66.5ppm/K in 26 μm of film thickness of Kapton.It presses The coefficient of linear thermal expansion value of Kapton made from the hot imide reaction, is far longer than by described in Examples 1 to 4 Chemical imidization so that by polyimide varnish cast film and prepare the same Kapton formed line heat it is swollen Swollen coefficient, and film is gonorrhoea, so then clear be not preferably film-made hot-imide again in the polyamic acid stage in the past 2 step processes.It is combined with other evaluation results and characteristic is listed in table 1.

(polymerization of polyimide precursor)

0.9607g (3mmol) TFMB is dissolved in 10.3g dehydration NMP.1.6033g is slowly added in the solution TA44BP powder described in (3mmol) synthesis example 2 stirs 5 days at room temperature, and polyamic acid is made, and (solid component concentration is 20.0 weight %).The inherent viscosity of polyamic acid is 1.99dL/g.

(chemical imidization reaction)

Gained polyamic acid solution is diluted to 10.0 weight % solid component concentrations with dehydration NMP, later at room temperature The mixed solution of 2.8mL (30mmol) acetic anhydride and 1.2mL (15mmol) pyridine is slowly added dropwise in wherein while stirring, at this time Reaction solution gelation, and chemical imidization reaction cannot be completed.This solvent solubility for being attributed to the polyimides does not fill Point.The result is shown in TAHMBP due to absolutely not substituent group on the central biphenylene of used TA44BP Substituent group plays how important role for the dissolubility of solvent.

(hot-imide of polyimide precursor)

The polyamic acid solution being polymerize with comparative example 1 is cast on the glass substrate, with hot-air drier in 80 DEG C dry 2 Hour.Thereafter, together with substrate in a vacuum at 250 DEG C, 1 hour, then at 350 DEG C, hot acid imide is carried out within 1 hour Change.After being cooled to room temperature, Kapton is removed from glass substrate.By the Kapton again in a vacuum in 350 DEG C are heat-treated 1 hour, and resulting Kapton is colored as by force yellow.

This result is due to absolutely not structure as substituent group on the central biphenylene of used TA44BP, table The substituent group being illustrated in TAHMBP is for inhibiting the coloring of film to be responsible for how important role.

[table 1]

[table 2]

CF

Acetone

THF

DOX

Ethyl acetate

CPN

CHN

DMF

DMAc

NMP

Metacresol

DMSO

GBL

Tri-GL

Embodiment 1

++

±

++^c

+

*

++^c

+

++

+

++

++^c

It is not carried out

Embodiment 5

++

-

+

++

++^b

++

+

++

+

++

+

++

Embodiment 6

-

+

-

+

++

+

++: room temperature is solvable ,+: be heated to it is solvable close to boiling point ,-: it is insoluble,

±: it expands, be partly dissolved,

B) gelation after a couple of days, c) it is homogeneous solution in several weeks

(the full light transmission rate and fuzzy value of polyimide film)

For the Kapton of Examples 1 to 3, embodiment 5, embodiment 6 and comparative example 2, with Japanese electric color work Industry Co. Ltd. system Haze Meter NDH4000 is measured using JIS (Japanese Industrial Standards) K7361 as the full light transmission rate of standard With using JIS K7136 as the fuzzy value of standard, measures 5 times average respectively, the index as the transparency.According to this as a result, The full light transmission rate of the polyimides of Examples 1 to 3 and embodiment 5 shows value sufficiently high, and fuzzy value is low.But compare The value of the Kapton of example 2 is poor, the sub- connection in center of the TA44BP used when being shown to be due to polyimides synthesis Absolutely not this structure of substituent group on phenyl, so that cannot inhibit to colour.

In addition, the full light transmission rate of the Kapton of embodiment 6,400nm light transmission rate, cutoff wavelength are significantly better than The Kapton of comparative example 2, so the transparency of the Kapton of embodiment 6 is substantially better than comparative example 2.It should say Bright, the fuzzy value of the Kapton of embodiment 6 is with 2 times of 2 Kapton of comparative example of film thickness measuring, so mould Paste value is more bigger than comparative example 2, but in view of the film thickness in each example, the Kapton of actually embodiment 6 is excellent 's.

[table 3]

Claims

1. a kind of polyimides, which is characterized in that containing structural unit shown in following formula (1),

Formula (1)

In formula, R each independently represents the alkyl of straight-chain or branched that hydrogen atom or carbon atom number are 1~4, but with it is same At least 1 is alkyl in 2 R that phenyl ring combines.

2. polyimides according to claim 1, which is characterized in that in formula (1), R is each independently represented selected from hydrogen original Son, methyl, ethyl, isopropyl, n-propyl, tert-butyl, isobutyl group group.

3. polyimides according to claim 1, which is characterized in that in formula (1), 2 R in conjunction with same phenyl ring are Alkyl.

4. a kind of polyimides, which is characterized in that contain structural unit shown in following formula (2)

Formula (2)

5. polyimides according to claim 1, which is characterized in that structural unit shown in formula (1) is with following formula (11) Shown in the structural unit that is manufactured as raw material of tetracarboxylic acid dianhydride

Formula (11)

6. polyimides according to claim 1, which is characterized in that shown in the following formula (1) containing 70 moles of % or more Structural unit,

Formula (1)

7. polyimides according to claim 6, which is characterized in that in formula (1), R is each independently represented selected from hydrogen original Son, methyl, ethyl, isopropyl, n-propyl, tert-butyl, isobutyl group group.

8. polyimides according to claim 6, which is characterized in that in formula (1), 2 R in conjunction with same phenyl ring are Alkyl.

9. polyimides according to claim 4, which is characterized in that shown in the following formula (2) containing 70 moles of % or more Structural unit

Formula (2)

10. polyimides according to claim 5, which is characterized in that use following formula (11) institute containing 70 moles of % or more The structural unit for the formula (1) that the tetracarboxylic acid dianhydride shown is manufactured as raw material

Formula (11)

11. polyimides according to claim 1, which is characterized in that in addition to the tetracarboxylic acid dianhydride shown in following formula (3), As copolymer composition, the acid anhydrides selected from following type is used with the range of 0~30 mole of % of whole tetracarboxylic acid dianhydride usage amounts: Pyromellitic acid anhydride, 3,3', 4,4'- bibenzene tetracarboxylic dianhydrides, hydroquinone-bis- (trimellitic anhydrides), methyl hydroquinone- Bis- (trimellitic anhydrides), Isosorbide-5-Nitrae, 5,8- naphthalenetetracarbacidic acidic dianhydrides, 2,3,6,7- naphthalenetetracarbacidic acidic dianhydrides, 3,3', 4,4'- benzophenone four Formic acid dianhydride, 3,3', 4,4'- Biphenyl Ether tetracarboxylic acid dianhydrides, 3,3', 4,4'- biphenyl sulfone tetracarboxylic acid dianhydrides, 2,2'- bis- (3,4- bis- Carboxyl phenyl) hexafluoro propionic acid dianhydride, bis- (3,4- dicarboxyphenyi) the propionic acid dianhydrides of 2,2'-, alkene -2,3 bicyclic [2.2.2] octyl- 7-, 5,6- tetracarboxylic acid dianhydride, 5- (dioxotetrahydrofuryl) -3- methyl -3- cyclohexene -1,2- dicarboxylic acid anhydride, 4- (2,5- dioxy For tetrahydrofuran -3- base)-naphthane -1,2- dicarboxylic acid anhydride, tetrahydrofuran -2,3,4,5- tetracarboxylic acid dianhydride, 1,2,3,4- ring fourth Alkane tetracarboxylic acid dianhydride, 1,2,3,4- cyclopentane tetracarboxylic acid dianhydride；Other than bis- (trifluoromethyl) benzidine of 2,2'-, as copolymerization Ingredient is used with the range of 0~30 mole of % of whole diamines usage amounts and is selected from p-phenylenediamine, m-phenylene diamine (MPD), 2,4- diamino Toluene, 2,5- diaminotoluene, 2,4- diamino dimethylbenzene, 2,4- diamino durol, 4,4'- diamino-diphenyl first Alkane, 4,4' methylene bis (2-aminotoluene), 4,4' methylene bis (2- ethyl aniline), 4,4' methylene bis (2,6- diformazan Base aniline), 4,4' methylene bis (2,6- diethylaniline), 4,4'- diamino-diphenyl ether, 3,4'- diamino-diphenyl Ether, 3,3'- diamino-diphenyl ether, 2,4'- diamino-diphenyl ether, 4,4'- diamino diphenyl sulfone, 3,3'- diamino two Phenylsulfone, 4,4'- diaminobenzophenone, 3,3'- diaminobenzophenone, 4,4'- diaminobenzene anilid, 4- aminobenzene Base -4'- Aminobenzoate, benzidine, 3,3'- dihydroxybiphenyl amine, 3,3'- dimethoxy benzidine, o-tolidine, connection Bis- (4- amino-benzene oxygen) benzene of toluidines, 1,4-, bis- (4- amino-benzene oxygen) benzene of 1,3-, bis- (3- amino-benzene oxygen) benzene of 1,3-, Bis- (4- amino-benzene oxygen) biphenyl of 4,4'-, bis- (4- (3- amino-benzene oxygen) benzene) sulfones, bis- (4- (4- amino-benzene oxygen) benzene) sulfones, 2,2- bis- (4- (4- amino-benzene oxygen) benzene) propane, 2,2- bis- (4- (4- amino-benzene oxygen) benzene) hexafluoropropane, bis- (the 4- ammonia of 2,2- Base phenyl) hexafluoropropane, to triphenyl diamine, 4,4'- di-2-ethylhexylphosphine oxide (cyclohexylamine), isophorone diamine, anti-form-1,4- diamino Butylcyclohexane, cis- -1,4- diaminocyclohexane, 1,4- hexamethylene bis- (methylamines), 2,5- bis- (amino methyls) are bicyclic (2.2.1) Bicyclic (2.2.1) heptane of heptane, 2,6- bis- (amino methyls), bis- (amino methyl) tricyclic (5.2.1.0) decane of 3,8-, 1,3- bis- Bis- (4- aminocyclohexyl) propane of aminoadamantan, 2,2-, bis- (4- aminocyclohexyl) hexafluoropropane of 2,2-, 1,3- propane diamine, Putriscine, 1,5- pentanediamine, 1,6- hexamethylene diamine, 1,7- heptamethylene diamine, 1,8- octamethylenediamine, 1,9- nonamethylene diamine, diamino silicon oxygen The diamines of alkane,

Formula (3)

12. a kind of polyimide varnish, which is characterized in that containing polyimides described in any one of claim 1~11 and Organic solvent.

13. polyimide varnish according to claim 12, which is characterized in that the organic solvent be selected from esters solvent, Ether solvent, carbonate-based solvent, glycol solvent, phenol solvent, at least one kind of agent of low hygroscopicity in ketones solvent are organic Solvent, and the solid component concentration of the polyimides is 5 mass % or more.

14. polyimide varnish according to claim 12, which is characterized in that the organic solvent be selected from gamma-butyrolacton, Gamma-valerolactone, δ-valerolactone, γ-hexalactone, 6-caprolactone, Alpha-Methyl-gamma-butyrolacton, n-butyl acetate, ethyl acetate, second Sour isobutyl ester, ethylene carbonate, propene carbonate, diethylene glycol dimethyl ether, triethylene glycol, triethylene glycol dimethyl ether, phenol, Cresols, paracresol, o-cresol, 3- chlorophenol, 4- chlorophenol, cyclopentanone, cyclohexanone, acetone, methyl ethyl ketone, diisobutyl ketone, methyl At least one of isobutyl ketone, tetrahydrofuran, 1,4- dioxane, dimethoxy-ethane, diethoxyethane, dibutyl ethers Agent of low hygroscopicity organic solvent, and the solid component concentration of the polyimides be 5 weight % or more.

15. a kind of polyimides formed body, which is characterized in that containing structural unit shown in following formula (1),

Formula (1)

16. polyimides formed body according to claim 15, which is characterized in that in formula (1), R is each independently represented Selected from hydrogen atom, methyl, ethyl, isopropyl, n-propyl, tert-butyl, isobutyl group group.

17. polyimides formed body according to claim 15, which is characterized in that in formula (1), in conjunction with same phenyl ring 2 R are alkyl.

18. a kind of polyimides formed body, which is characterized in that contain structural unit shown in following formula (2)

Formula (2)

19. polyimides formed body according to claim 15, which is characterized in that structural unit shown in formula (1) is to use The structural unit that tetracarboxylic acid dianhydride shown in following formula (11) is manufactured as raw material

Formula (11)

20. polyimides formed body according to claim 15, which is characterized in that formed body is film.

21. a kind of Kapton, which is characterized in that be by polyimides described in any one of claim 12~14 Varnish is coated and dried on substrate and removes and be made from substrate.

22. Kapton according to claim 21, which is characterized in that when the film thickness of Kapton is 10 μm When, the light transmission rate under 400nm is 45% or more, or when film thickness is 20 μm, full light transmission rate is 80% or more.

23. Kapton according to claim 22, which is characterized in that the light when film thickness is 10 μm, under 400nm Transmitance is 50% or more.

24. Kapton according to claim 22, which is characterized in that the light when film thickness is 10 μm, under 400nm Transmitance is 60% or more.

25. Kapton according to claim 22, which is characterized in that the light when film thickness is 10 μm, under 400nm Transmitance is 80% or more.

26. Kapton according to claim 22, which is characterized in that when film thickness is 20 μm, full light transmission rate It is 85% or more.

27. Kapton according to claim 21, which is characterized in that when the film thickness of Kapton is 10 μm When, the light transmission rate under 400nm is 45% or more, and when film thickness is 10 μm, full light transmission rate is 70% or more.

28. Kapton according to claim 27, which is characterized in that when film thickness is 10 μm, full light transmission rate It is 80% or more.

29. Kapton according to claim 27, which is characterized in that when film thickness is 10 μm, full light transmission rate It is 85% or more.

30. Kapton according to claim 27, which is characterized in that the light when film thickness is 10 μm, under 400nm Transmitance is 50% or more.

31. Kapton according to claim 27, which is characterized in that the light when film thickness is 10 μm, under 400nm Transmitance is 60% or more.

32. Kapton according to claim 27, which is characterized in that the light when film thickness is 10 μm, under 400nm Transmitance is 80% or more.

33. the synthetic method of polyimides of the one kind containing structural unit shown in following formula (1), which is characterized in that by polyamides Asia Heating temperature is lower than 150 DEG C when amine precursor imidizate,

Formula (1)

34. the synthetic method of polyimides according to claim 33, which is characterized in that in formula (1), R is each independently Indicate the group for being selected from hydrogen atom, methyl, ethyl, isopropyl, n-propyl, tert-butyl, isobutyl group.

35. the synthetic method of polyimides according to claim 33, which is characterized in that in formula (1), with same phenyl ring knot 2 R closed are alkyl.

36. the synthetic method of polyimides of the one kind containing structural unit shown in following formula (2), which is characterized in that by polyamides Asia Heating temperature is lower than 150 DEG C when amine precursor imidizate

Formula (2)

37. the synthetic method of polyimides according to claim 33, which is characterized in that structural unit shown in formula (1) It is the structural unit for using tetracarboxylic acid dianhydride shown in following formula (11) to manufacture as raw material

Formula (11)

38. the synthetic method of polyimides according to claim 33, which is characterized in that by polyimide precursor acid imide When change, in the presence of the dehydration closed-loop agent being made of organic acid anhydride and basic catalyst, with 0~100 DEG C of heating temperature into The row imidizate.

39. the synthetic method of polyimides according to claim 33, which is characterized in that by polyimide precursor acid imide When change, in the presence of the dehydration closed-loop agent being made of organic acid anhydride and basic catalyst, with 10~50 DEG C of heating temperature into The row imidizate.

40. the synthetic method of the polyimides according to claim 38 or 39, which is characterized in that the organic acid anhydride is acetic acid Acid anhydride or propionic andydride, the basic catalyst are pyridine, triethylamine or quinoline.