JP7047852B2 - Polyimide precursors, polyimides, polyimide films, varnishes, and substrates - Google Patents

Description

The present invention relates to a polyimide having high transparency, a low coefficient of linear thermal expansion, and a small retardation in the thickness direction, and a precursor thereof. The present invention also relates to a polyimide film, a polyimide precursor or a varnish containing polyimide, and a substrate.

In recent years, with the advent of the advanced information society, the development of optical materials such as optical fibers and optical waveguides in the optical communication field, liquid crystal alignment films in the display device field, and protective films for color filters has been progressing. Especially in the field of display devices, a lightweight and highly flexible plastic substrate is being studied as an alternative to a glass substrate, and a display that can be bent or rolled is being actively developed. Therefore, there is a demand for higher performance optical materials that can be used for such applications.

Aromatic polyimides are essentially tan due to intramolecular conjugation and formation of charge transfer complexes. Therefore, as a means for suppressing coloring, for example, by introducing a fluorine atom into the molecule, imparting flexibility to the main chain, introducing a bulky group as a side chain, etc., the formation of intramolecular conjugation and charge transfer complex is inhibited. Then, a method of expressing transparency has been proposed.

Further, a method of exhibiting transparency by using a semi-alicyclic or full alicyclic polyimide that does not form a charge transfer complex in principle has also been proposed. In particular, a highly transparent semi-alicyclic polyimide using an aromatic tetracarboxylic dianhydride as a tetracarboxylic acid component and an alicyclic diamine as a diamine component, and an alicyclic tetracarboxylic acid dianhydride as a tetracarboxylic acid component. Many highly transparent semi-lipid ring-type polyimides using aromatic diamine as an anhydride and diamine components have been proposed.

For example, in Patent Document 1, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetra as a tetracarboxylic acid component. Carboxylic acid dianilides (abbreviation: CpODA) is used, and 2,2'-bis (trifluoromethyl) benzidine (abbreviation: TFMB) or TFMB and other aromatic diamines (eg, TFMB:) are used as diamine components. A polyimide using 4,4'-diaminobenzanilide: 9,9-bis (4-aminophenyl) fluorene = 5: 4: 1 (molar ratio)) is disclosed. Patent Document 2 uses CpODA having a specific stereoisomer ratio as the tetracarboxylic acid component, TFMB as the diamine component, and other aromatic diamines (eg, TFMB: 4,4'-diaminobenzanilide). = 5: 5 (molar ratio), etc.) is disclosed.

Further, Patent Document 3 describes a polyimide resin containing a structural unit A derived from tetracarboxylic acid dianhydride and a structural unit B derived from a diamine compound, wherein the structural unit A is a structural unit derived from CpODA. (A-1), the structural unit (A-2) derived from pyromellitic acid dianhydride, and the structural unit (A-3) derived from 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride. The constituent unit B comprises at least one of the constituent units (B-1) derived from 9,9-bis (4-aminophenyl) fluorene, and the constituent unit (B-1) in the constituent unit B. A polyimide resin having a ratio of 60 mol% or more is disclosed. More specifically, in Example 4 of Patent Document 3, a polyimide resin is produced from CpODA (A-1) and 9,9-bis (4-aminophenyl) fluorene (B-1). In Example 5 of Patent Document 3, CpODA (A-1), 1,2,4,5-cyclohexanetetracarboxylic dianhydride (A-3) and 9,9-bis (4-aminophenyl) fluorene ( A polyimide resin ((A-1) :( A-3) = 1: 1 (molar ratio)) is produced from B-1). In Example 6 of Patent Document 3, a polyimide resin is obtained from CpODA (A-1), 9,9-bis (4-aminophenyl) fluorene (B-1), and 2,2'-dimethylbenzidine (B-2). ((B-1) :( B-2) = 4: 1 (molar ratio)) is manufactured.

Further, in Example 1 and Comparative Example 1 of Patent Document 4, CpODA, 4,4'-diamino-2,2'-dimethylbiphenyl and 9,9-bis (4-aminophenyl) fluorene (molar ratio:: The polyimide obtained from 1/1) and the polyimide obtained from CpODA and 9,9-bis (4-aminophenyl) fluorene are described.

International Publication No. 2013/179727 International Publication No. 2014/046064 International Publication No. 2017/191822 Japanese Unexamined Patent Publication No. 2017-13302

Depending on the application, for example, in display applications, polyimides and polyimide films having high transparency, a low coefficient of linear thermal expansion, and a small thickness direction retardation are required. When light is transmitted through a film having a large phase difference in the thickness direction, problems such as the color of the transmitted light not being displayed correctly, color bleeding, and a narrow viewing angle may occur. Therefore, it is desired to reduce the phase difference in the thickness direction, especially in display applications.

An object of the present invention is to provide a polyimide having high transparency, a low coefficient of linear thermal expansion, and a small retardation in the thickness direction, and a precursor thereof.

The present invention relates to the following items.
1. 1. A polyimide precursor containing a repeating unit represented by the following general formula (1).
A ₁ of the following general formula (1) contains a tetravalent group represented by the following formula (A-1), and B ₁ of the following general formula (1) is represented by the following formula (B-1). Including the represented divalent group
Further, A ₁ and / or B ₁ of the following general formula (1) contains a tetravalent or divalent group containing a structure represented by the following formula (2), or the following general formula (1). A ₁ contains a tetravalent group represented by the following formula (3) and / or a tetravalent group represented by the following formula (4).
The tetravalent group represented by the formula (A-1) in A ₁ 100 mol% of the general formula (1), the tetravalent group including the structure represented by the formula (2), and the formula (3). It is represented by the total content ratio of the tetravalent groups represented by the formula (4) and the tetravalent groups represented by the formula (4), and the formula (B-1) in B ₁ 100 mol% of the general formula (1). The sum of the total content ratios of the divalent groups and the divalent groups including the structure represented by the formula (2) is 120 mol% or more.
However, the tetravalent group represented by the formula (A-1), the tetravalent group including the structure represented by the formula (2), the tetravalent group represented by the formula (3), and the formula ( With respect to the total of the tetravalent groups represented by 4), the tetravalent group including the structure represented by the formula (2), the tetravalent group represented by the formula (3), and the formula (4). The ratio of the represented tetravalent group is 80 mol% or less, and
The divalent group including the structure represented by the formula (2) with respect to the total of the divalent groups represented by the formula (B-1) and the divalent group including the structure represented by the formula (2). A polyimide precursor characterized by having a group ratio of 80 mol% or less.

（式中、Ａ_１は芳香族環または脂環構造を有する４価の基であり、Ｂ_１は芳香族環または脂環構造を有する２価の基であり、Ｒ_１、Ｒ_２はそれぞれ独立に水素、炭素数１～６のアルキル基、または炭素数３～９のアルキルシリル基である。ただし、各繰り返し単位に含まれるＡ_１およびＢ_１は、同一であっても異なっていてもよい。）

(In the formula, A ₁ is a tetravalent group having an aromatic ring or an alicyclic structure, B ₁ is a divalent group having an aromatic ring or an alicyclic structure, and R ₁ and R ₂ are independent of each other. A hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. However, A ₁ and B ₁ contained in each repeating unit may be the same or different. .)

2. 2. A polyimide containing a repeating unit represented by the following general formula (5).
A ₂ of the following general formula (5) contains a tetravalent group represented by the following formula (A-1), and B ₂ of the following general formula (5) is the following formula (B-1). Including the represented divalent group
Further, A ₂ and / or B ₂ of the following general formula (5) contains a tetravalent or divalent group containing a structure represented by the following formula (2), or the following general formula (5). A ₂ contains a tetravalent group represented by the following formula (3) and / or a tetravalent group represented by the following formula (4).
The tetravalent group represented by the formula (A-1) in A ₂ 100 mol% of the general formula (5), the tetravalent group including the structure represented by the formula (2), and the formula (3). It is represented by the total content ratio of the tetravalent groups represented by the formula (4) and the tetravalent groups represented by the formula (4), and the formula (B-1) in B ₂ 100 mol% of the general formula (5). The sum of the total content ratios of the divalent groups and the divalent groups including the structure represented by the formula (2) is 120 mol% or more.
However, the tetravalent group represented by the formula (A-1), the tetravalent group including the structure represented by the formula (2), the tetravalent group represented by the formula (3), and the formula ( With respect to the total of the tetravalent groups represented by 4), the tetravalent group including the structure represented by the formula (2), the tetravalent group represented by the formula (3), and the formula (4). The ratio of the represented tetravalent group is 80 mol% or less, and
The divalent group including the structure represented by the formula (2) with respect to the total of the divalent groups represented by the formula (B-1) and the divalent group including the structure represented by the formula (2). A polyimide having a group ratio of 80 mol% or less.

（式中、Ａ_２は芳香族環または脂環構造を有する４価の基であり、Ｂ_２は芳香族環または脂環構造を有する２価の基である。ただし、各繰り返し単位に含まれるＡ_２およびＢ_２は、同一であっても異なっていてもよい。）

(In the formula, A ₂ is a tetravalent group having an aromatic ring or an alicyclic structure, and B ₂ is a divalent group having an aromatic ring or an alicyclic structure. However, it is included in each repeating unit. A ₂ and B ₂ may be the same or different.)

3. 3. A polyimide obtained from the polyimide precursor according to Item 1.
4. A varnish containing the polyimide precursor according to item 1 or the polyimide according to item 2.
5. A polyimide film obtained by using the polyimide precursor according to Item 1 or a varnish containing the polyimide according to Item 2.
6. A laminate comprising the polyimide according to Item 2 or 3 or the polyimide film according to Item 5 formed on a glass substrate.
7. A substrate for a display, a touch panel, or a solar cell, which comprises the polyimide according to Item 2 or 3 or the polyimide film according to Item 5.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a polyimide having high transparency, a low coefficient of linear thermal expansion, and a small retardation in the thickness direction, and a precursor thereof.

Since the polyimide obtained from the polyimide precursor of the present invention and the polyimide of the present invention have high transparency, a low coefficient of linear thermal expansion, and a small retardation in the thickness direction, they form a substrate for display applications and the like. Can be suitably used for this purpose. Further, the polyimide obtained from the polyimide precursor of the present invention and the polyimide of the present invention can be suitably used for forming a substrate for a touch panel and a solar cell.

The polyimide precursor of the present invention is a polyimide precursor containing a repeating unit represented by the general formula (1). The total content of the repeating unit represented by the general formula (1) is preferably 90 mol% or more, more preferably 95 mol% or more, and particularly 100 mol% with respect to all the repeating units. preferable. A ₁ in the general formula (1) is a tetravalent group having an aromatic ring or an alicyclic structure, and is preferably a tetravalent group having an alicyclic structure. B ₁ in the general formula (1) is a divalent group having an aromatic ring or an alicyclic structure, and is preferably a divalent group having an aromatic ring.

In the polyimide precursor of the present invention, A1 in the general formula (1) contains a tetravalent group represented by the formula (A- ₁ ), and the polyimide precursor in the general formula (1) contains a tetravalent group. B ₁ contains a divalent group represented by the formula (B-1), and A ₁ and / or B ₁ of the general formula (1) is represented by the formula (2). It contains a tetravalent or divalent group containing, or A1 of the general formula ( ₁ ) is represented by a tetravalent group represented by the formula (3) and / or represented by the formula (4). Includes a tetravalent group. A ₁ and / or B ₁ contains a tetravalent or divalent group containing the structure represented by the formula (2), and A ₁ is a tetravalent group represented by the formula (3). And / or it may contain a tetravalent group represented by the above formula (4).

Further, their content is a tetravalent group represented by the formula (A-1) and a tetravalent group represented by the formula (2) in 100 mol% of A ₁ of the general formula (1). The total content ratio of the group, the tetravalent group represented by the formula (3), and the tetravalent group represented by the formula (4), and the formula in B ₁ 100 mol% of the general formula (1). The sum of the total content ratios of the divalent group represented by (B-1) and the divalent group including the structure represented by the formula (2) is 120 mol% or more, preferably 160. It is preferably mol% or more, more preferably 180 mol% or more. However, it is represented by the tetravalent group represented by the formula (A-1) in A ₁ of the general formula (1), the tetravalent group including the structure represented by the formula (2), and the formula (3). The tetravalent group including the structure represented by the formula (2) and the tetravalent group represented by the formula (3) with respect to the sum of the tetravalent group and the tetravalent group represented by the formula (4). The ratio of the group and the tetravalent group represented by the formula (4) is 80 mol% or less, and the divalent group represented by the formula (B-1) in B ₁ of the general formula (1). The ratio of the divalent group containing the structure represented by the formula (2) to the total of the group and the divalent group containing the structure represented by the formula (2) is 80 mol% or less. The sum of these two ratios is preferably 125 mol% or less.

The polyimide of the present invention is a polyimide containing a repeating unit represented by the general formula (5). The total content of the repeating unit represented by the general formula (5) is preferably 90 mol% or more, more preferably 95 mol% or more, and particularly 100 mol% with respect to all the repeating units. preferable. A ₂ in the general formula (5) is a tetravalent group having an aromatic ring or an alicyclic structure, and is preferably a tetravalent group having an alicyclic structure. B ₂ in the general formula (5) is a divalent group having an aromatic ring or an alicyclic structure, and is preferably a divalent group having an aromatic ring.

In the polyimide of the present invention, A ₂ in the general formula (5) contains a tetravalent group represented by the formula (A-1), and B ₂ in the general formula (5). Includes a divalent group represented by the formula (B-1), and further comprises a structure in which A ₂ and / or B ₂ of the general formula (5) is represented by the formula (2). It contains a tetravalent or divalent group, or A ₂ of the general formula (5) is represented by a tetravalent group represented by the formula (3) and / or represented by the formula (4). Includes valence base. A ₂ and / or B ₂ contains a tetravalent or divalent group containing the structure represented by the formula (2), and A ₂ is a tetravalent group represented by the formula (3). And / or it may contain a tetravalent group represented by the above formula (4).

Further, their content is a tetravalent group represented by the formula (A-1) and a tetravalent group represented by the formula (2) in 100 mol% of A ₂ of the general formula (5). The total content ratio of the group, the tetravalent group represented by the formula (3), and the tetravalent group represented by the formula (4), and the formula in B ₂ 100 mol% of the general formula (5). The sum of the total content ratios of the divalent group represented by (B-1) and the divalent group including the structure represented by the formula (2) is 120 mol% or more, preferably 160. It is preferably mol% or more, more preferably 180 mol% or more. However, it is represented by the tetravalent group represented by the formula (A-1) in A ₂ of the general formula (5), the tetravalent group including the structure represented by the formula (2), and the formula (3). The tetravalent group including the structure represented by the formula (2) and the tetravalent group represented by the formula (3) with respect to the sum of the tetravalent group and the tetravalent group represented by the formula (4). The ratio of the group and the tetravalent group represented by the formula (4) is 80 mol% or less, and the divalent group represented by the formula (B-1) in B ₂ of the general formula (5). The ratio of the divalent group containing the structure represented by the formula (2) to the total of the group and the divalent group containing the structure represented by the formula (2) is 80 mol% or less. The sum of these two ratios is preferably 125 mol% or less.

In the present specification, the following abbreviations are used as appropriate.

CpODA: Norbornan-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornan-5,5'', 6,6''-tetracarboxylic acid dianhydride CpODA, etc .: Norbornan-2- Spiro-α-cyclopentanone-α'-spiro-2''-norbornan-5,5'', 6,6''-tetracarboxylic acids, etc. (Tetracarboxylic acids, etc. are tetracarboxylic acid and tetracarboxylic acid. Represents a tetracarboxylic acid derivative such as acid dianhydride, tetracarboxylic acid silyl ester, tetracarboxylic acid ester, tetracarboxylic acid chloride)
TFMB: 2,2'-bis (trifluoromethyl) benzidine The tetracarboxylic acid component that gives a tetravalent group represented by the above formula (A-1) is CpODA or the like, and is represented by the above formula (B-1). The diamine component that gives the represented divalent group is TFMB. Polyimide obtained from CpODA or the like and TFMB, that is, A ₁ is a tetravalent group represented by the above formula (A-1), and B ₁ is a divalent group represented by the above formula (B-1). The polyimide obtained from the polyimide precursor consisting of the repeating unit of the general formula (1) as a group, A ₂ is a tetravalent group represented by the formula (A-1), and B ₂ is the formula. The polyimide composed of the repeating unit of the general formula (5), which is a divalent group represented by (B-1), has high transparency and a low coefficient of linear thermal expansion, but has a retardation in the thickness direction. It tends to be relatively large. When the polyimide film is used for a display application or the like, as described above, if the phase difference in the thickness direction is large, problems such as the color of transmitted light not being displayed correctly, color bleeding, and a narrow viewing angle may occur. On the other hand, in the above content (ratio), it is derived from A ₁ of the general formula (1), A ₂ of the general formula (5), and / or the diamine component, which is a structure derived from the tetracarboxylic acid component. A group containing the structure represented by the above formula (2) is introduced into B ₁ of the general formula (1) and B ₂ of the general formula (5), or a structure derived from the tetracarboxylic acid component. A ₁ of the general formula (1) and A ₂ of the general formula (5) have a tetravalent group represented by the formula (3) and / or a tetravalent group represented by the formula (4). By introducing it, it is possible to reduce the retardation in the thickness direction while maintaining high transparency and a low linear thermal expansion coefficient. As a result, it is possible to obtain a polyimide having high transparency, a low coefficient of linear thermal expansion, and a small retardation in the thickness direction.

Here, in the structure represented by the above formula (2), adjacent aromatic rings may be further linked by a direct bond, an ether bond, or the like, and for example, the structure represented by the following formula (2'). There may be.

（式中、Ｒは直接結合、またはエーテル結合（－Ｏ－）である。）

(In the formula, R is a direct bond or an ether bond (-O-).)

Further, even if the aromatic ring contained in the structure represented by the above formula (2) is substituted with an alkyl group such as a methyl group, a fluorinated alkyl group such as a trifluoromethyl group, or a substituent such as a halogeno group. It is good, but usually it is preferable to have no substituent. The replacement position is not particularly limited.

The tetracarboxylic acid component that gives a tetravalent group containing the structure represented by the formula (2) is a tetracarboxylic acid or the like containing the structure represented by the formula (2), and is, for example, 9,9'-. Tetracarboxylic acid derivatives other than tetracarboxylic acid dianhydride, such as bis (3,4-dicarboxyphenyl) fluorene dianhydride and other derivatives (tetracarboxylic acid silyl ester, tetracarboxylic acid ester, tetracarboxylic acid chloride, etc.) ) Etc. can be mentioned. The diamine component that gives a divalent group containing the structure represented by the formula (2) is a diamine containing the structure represented by the formula (2), and is, for example, 9,9-bis (4-aminophenyl). ) Fluorene, 9,9-bis (4-amino-3-chlorophenyl) fluorene, 9,9-bis (4-amino-3-fluorophenyl) fluorene, 9,9-bis (4-amino-3-methylphenyl) ) Fluorene, 4,4'-(spiro [fluorene-9,9'-xanthene] -3', 6'-diylbis (oxy)) dianiline and the like.

Further, the tetracarboxylic acid component giving a tetravalent group represented by the above formula (3) is 1,2,4,5-cyclohexanetetracarboxylic acids and the like.

The tetracarboxylic acid component giving a tetravalent group represented by the formula (4) is 2,3,3', 4'-biphenyltetracarboxylic acids and the like.

In other words, the polyimide precursor of the present invention and the polyimide of the present invention are
(A-1) With CpODA etc.
(A-2) Tetracarboxylic acids and the like containing the structure represented by the above formula (2), 1,2,4,5-cyclohexanetetracarboxylic acids and the like, 2,3,3', 4'-biphenyltetracarboxylic acids and the like. A tetracarboxylic acid component containing any one or more of them, and
(B) Is it obtained from a diamine component containing TFMB or a diamine component containing TFMB and a diamine containing the structure represented by the formula (2)?
or,
(A) A tetracarboxylic acid component containing CpODA and the like,
(B) Obtained from a diamine component including TFMB and a diamine containing the structure represented by the formula (2).

Of the six stereoisomers, the tetracarboxylic acid component CpODA used here is trans-endo-endo-norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane. -5,5'', 6,6''-tetracarboxylic acids, etc. (trans-endo-endo form) and / or cis-endo-endo-norbornane-2-spiro-α-cyclopentanone-α'-spiro -2''-Norbornane-5,5'', 6,6''-Tetracarboxylic acids and the like (cis-endo-endo form) may be preferable. In certain embodiments, the proportion of trans-endo-endo and / or cis-endo-endo in total, such as CpODA, is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 90 mol% or more. It is preferably 95 mol% or more, particularly preferably 99 mol% or more.

As the tetracarboxylic acid component 1,2,4,5-cyclohexanetetracarboxylic acids and the like used here, among the six types of stereoisomers, those containing 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic acids and the like are included. It may be preferable. In certain embodiments, the proportion of 1R, 2S, 4S, 5R-cyclohexanetetracarboxylic acids in 1,2,4,5-cyclohexanetetracarboxylic acids and the like is preferably 50 mol% or more, more preferably 80 mol%. As mentioned above, it is more preferably 90 mol% or more, and particularly preferably 95 mol% or more.

As CpODA or the like, one type may be used alone, or a plurality of types may be used in combination. Further, tetracarboxylic acids and the like containing the structure represented by the above formula (2), 1,2,4,5-cyclohexanetetracarboxylic acids and the like, and 2,3,3', 4'-biphenyltetracarboxylic acids and the like. Also, one type may be used alone, or a plurality of types may be used in combination. As for the diamine containing the structure represented by the formula (2), one type may be used alone, or a plurality of types may be used in combination.

The other tetracarboxylic acid component that gives the repeating unit represented by the general formula (1) or the repeating unit represented by the general formula (5) is either another aromatic or an alicyclic tetracarboxylic acid. Can also be used. Although not particularly limited, for example, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane and 4- (2,5-dioxotetratetra-3-yl) -1,2,3 4-Tetrahydronaphthalene-1,2-dicarboxylic acid, pyromellitic acid, 3,3', 4,4'-benzophenone tetracarboxylic acid, 3,3', 4,4'-biphenyltetracarboxylic acid, 4,4' -Oxydiphthalic acid, bis (3,4-dicarboxyphenyl) sulfonate dianhydride, m-terphenyl-3,4,3', 4'-tetracarboxylic acid dianhydride, p-terphenyl-3,4 3', 4'-tetracarboxylic acid dianhydride, biscarboxyphenyldimethylsilane, bisdicarboxyphenoxydiphenylsulfide, sulfonyldiphthalic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, isopropyridenediphenoxybisphthalic acid Acid, [1,1'-bi (cyclohexane)]-3,3', 4,4'-tetracarboxylic acid, [1,1'-bi (cyclohexane)]-2,3,3', 4'- Tetracarboxylic acid, [1,1'-bi (cyclohexane)]-2,2', 3,3'-tetracarboxylic acid, 4,4'-methylenebis (cyclohexane-1,2-dicarboxylic acid), 4,4 '-(Propane-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid), 4,4'-oxybis (cyclohexane-1,2-dicarboxylic acid), 4,4'-thiobis (cyclohexane-1) , 2-dicarboxylic acid), 4,4'-sulfonylbis (cyclohexane-1,2-dicarboxylic acid), 4,4'-(dimethylsilanediyl) bis (cyclohexane-1,2-dicarboxylic acid), 4,4 '-(Tetrafluoropropane-2,2-diyl) bis (cyclohexane-1,2-dicarboxylic acid), octahydropentalene-1,3,4,6-tetracarboxylic acid, bicyclo [2.2.1] Heptane-2,3,5,6-tetracarboxylic acid, 6- (carboxymethyl) bicyclo [2.2.1] heptane-2,3,5-tricarboxylic acid, bicyclo [2.2.2] octane-2 , 3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octa-5-en-2,3,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] decane -3,4,7,8-tetracarboxylic acid, tricyclo [4.2.2.02,5] deca-7-ene-3,4,9,10-tetracarboxylic acid, 9-oxato Licyclo [4.2.1.02,5] nonane-3,4,7,8-tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2c, 3c, 6c, 7c-tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2t, 3t, 6c, 7c-tetracarboxylic acid, and derivatives of these tetracarboxylic acids ( (Tetracarboxylic acid dianhydride, etc.) and the like. Among these, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 4,4'-oxydiphthalic acid, 1,2,3,4-cyclobutanetetracarboxylic acid, (4arH, 8acH)- Decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2c, 3c, 6c, 7c-tetracarboxylic acid, (4arH, 8acH) -decahydro-1t, 4t: 5c, 8c-dimethanonaphthalene-2t, 3t, Derivatives such as 6c and 7c-tetracarboxylic acids and acid dianhydrides thereof are more preferable. These tetracarboxylic acid components may be used alone or in combination of two or more.

As the other diamine component that gives the repeating unit of the general formula (1) or the repeating unit represented by the general formula (5), any of other aromatic or alicyclic diamines can be used. .. Although not particularly limited, for example, p-phenylenediamine, m-phenylenediamine, benzidine, 3,3'-diamino-biphenyl, 3,3'-bis (trifluoromethyl) benzidine, m-trizine, 4, 4'-diaminobenzanilide, 3,4'-diaminobenzanilide, N, N'-bis (4-aminophenyl) terephthalamide, N, N'-p-phenylenebis (p-aminobenzamide), 4-amino Phenoxy-4-diaminobenzoate, bis (4-aminophenyl) terephthalate, biphenyl-4,4'-dicarboxylic acid bis (4-aminophenyl) ester, p-phenylene bis (p-aminobenzoate), bis (4-amino) Phenyl)-[1,1'-biphenyl] -4,4'-dicarboxylate, [1,1'-biphenyl] -4,4'-diylbis (4-aminobenzoate), 4,4'-oxydi Aniline, 3,4'-oxydianiline, 3,3'-oxydianiline, bis (4-aminophenyl) sulfide, p-methylenebis (phenylenediamine), 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 2,2- Bis (4-aminophenyl) hexafluoropropane, bis (4-aminophenyl) sulfone, 3,3-bis ((aminophenoxy) phenyl) propane, 2,2-bis (3-amino-4-hydroxyphenyl) hexa Fluoropropane, bis (4- (4-aminophenoxy) diphenyl) sulfone, bis (4- (3-aminophenoxy) diphenyl) sulfone, octafluorobenzidine, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-difluoro-4,4'-diaminobiphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, 4,4'-bis (3-Aminophenoxy) Biphenyl, 1,4-diaminocyclohexane, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 1,4-diamino-2-n-propyl Cyclohexane, 1,4-diamino-2-isopropylcyclohexane, 1,4-diamino-2-n-butylcyclohexane, 1,4-di Amino-2-isobutylcyclohexane, 1,4-diamino-2-sec-butylcyclohexane, 1,4-diamino-2-tert-butylcyclohexane, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane Etc. and derivatives thereof. Among these, p-phenylenediamine, m-tridin, 4,4'-oxydianiline, 1,4-bis (4-aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) biphenyl and the like. Is more preferable. These diamine components may be used alone or in combination of two or more.

The polyimide precursor of the present invention and the polyimide of the present invention are one or more of other repeating units other than the repeating unit represented by the general formula (1) or the repeating unit represented by the general formula (5). It may contain. The tetracarboxylic acid component and the diamine component that give other repeating units are not particularly limited, and any other known tetracarboxylic acid or known diamine can be used. If the diamine component to be combined is not a diamine component that gives a repeating unit represented by the general formula (1) or a repeating unit represented by the general formula (5), the tetracarboxylic acid component that gives another repeating unit is An example of a tetracarboxylic acid component (CpODA or the like, which gives a repeating unit represented by the general formula (1) or a repeating unit represented by the general formula (5)) is represented by the formula (2). (Including tetracarboxylic acids and the like, 1,2,4,5-cyclohexanetetracarboxylic acids and the like, 2,3,3', 4'-biphenyltetracarboxylic acids and the like) may be used. If the tetracarboxylic acid component to be combined is not a repeating unit represented by the general formula (1) or a tetracarboxylic acid component giving a repeating unit represented by the general formula (5), a diamine component giving another repeating unit. Is exemplified as a diamine component giving a repeating unit represented by the general formula (1) or a repeating unit represented by the general formula (5) (TFMB, a structure represented by the formula (2)). It may be (including diamine).

In the polyimide precursor of the present invention, R ₁ and R ₂ in the general formula (1) are independently hydrogen and an alkyl group having 1 to 6 carbon atoms, preferably 1 to 3 carbon atoms (particularly preferably a methyl group or a methyl group). It is either an ethyl group) or an alkylsilyl group having 3 to 9 carbon atoms (particularly preferably a trimethylsilyl group or a t-butyldimethylsilyl group). The types of functional groups and the introduction rate of functional groups of R ₁ and R ₂ can be changed by the production method described later.

The introduction rate of the functional group is not particularly limited, but when an alkyl group or an alkylsilyl group is introduced, R ₁ and R ₂ each have an alkyl group of 25% or more, preferably 50% or more, and more preferably 75% or more. Alternatively, it can be an alkylsilyl group. By using 25% or more of each of R ₁ and R ₂ as an alkyl group or an alkylsilyl group, the storage stability of the polyimide precursor is excellent.

The polyimide precursor of the present invention independently has 1) polyamic acid (R ₁ and R ₂ are hydrogen) and 2) polyamic acid ester (at least of R ₁ and R ₂ ) depending on the chemical structure taken by R ₁ and R ₂ . It can be classified into 3) 4) polyamic acid silyl esters (at least a part of R ₁ and R ₂ are alkyl silyl groups). The polyimide precursor of the present invention can be easily produced by the following production methods for each of these categories. However, the method for producing the polyimide precursor of the present invention is not limited to the following production method.

1) Polyimide acid In the polyimide precursor of the present invention, the tetracarboxylic acid dianhydride as the tetracarboxylic acid component and the diamine component are substantially equimolar, preferably the molar ratio of the diamine component to the tetracarboxylic acid component [diamine]. The number of moles of the component / the number of moles of the tetracarboxylic acid component] is preferably at a ratio of 0.90 to 1.10, more preferably 0.95 to 1.05, for example, imidized at a relatively low temperature of 120 ° C. or lower. By reacting while suppressing the above, a polyimide precursor solution composition can be suitably obtained.

The method for synthesizing the polyimide precursor of the present invention is not limited, but more specifically, diamine is dissolved in an organic solvent, and tetracarboxylic acid dianhydride is gradually added while stirring in this solution. , 0 to 120 ° C., preferably 5 to 80 ° C. for 1 to 72 hours to obtain a polyimide precursor. The order of adding diamine and tetracarboxylic dianhydride in the above production method is preferable because the molecular weight of the polyimide precursor tends to increase. It is also possible to reverse the order of addition of the diamine and the tetracarboxylic dianhydride in the above production method, which is preferable because the precipitates are reduced.

When the molar ratio of the tetracarboxylic acid component to the diamine component is excessive, a carboxylic acid derivative in an amount substantially corresponding to the excess molar number of the diamine component is added as necessary, and the tetracarboxylic acid component and the diamine are added. The molar ratio of the components can be brought close to the equivalent amount. The carboxylic acid derivative here is a tetracarboxylic acid that does not substantially increase the viscosity of the polyimide precursor solution, that is, that does not substantially participate in molecular chain extension, or a tricarboxylic acid and its anhydride that function as a terminal terminator. Dicarboxylic acids and their anhydrides are suitable.

2) Polyamic acid ester Tetracarboxylic acid dianhydride is reacted with an arbitrary alcohol to obtain a diester dicarboxylic acid, which is then reacted with a chlorination reagent (thionyl chloride, oxalyl chloride, etc.) to obtain a diester dicarboxylic acid chloride. A polyimide precursor can be obtained by stirring the diester dicarboxylic acid chloride and diamine at −20 to 120 ° C., preferably −5 to 80 ° C. for 1 to 72 hours. Further, a polyimide precursor can be easily obtained by dehydrating and condensing a diesterdicarboxylic acid and a diamine using a phosphorus-based condensing agent, a carbodiimide condensing agent, or the like.

Since the polyimide precursor obtained by this method is stable, purification such as reprecipitation can be performed by adding a solvent such as water or alcohol.

3) Polyamic acid silyl ester (indirect method)
A diamine is reacted with a silylating agent in advance to obtain a silylated diamine. If necessary, the silylated diamine is purified by distillation or the like. Then, the silylated diamine is dissolved in the dehydrated solvent, and the tetracarboxylic acid dianhydride is gradually added while stirring, and the temperature is in the range of 0 to 120 ° C, preferably 5 to 80 ° C. A polyimide precursor can be obtained by stirring for about 72 hours.

As the silylating agent used here, it is preferable to use a silylating agent that does not contain chlorine because it is not necessary to purify the silylated diamine. Examples of the silylating agent containing no chlorine atom include N, O-bis (trimethylsilyl) trifluoroacetamide, N, O-bis (trimethylsilyl) acetamide, and hexamethyldisilazane. N, O-bis (trimethylsilyl) acetamide and hexamethyldisilazane are particularly preferable because they do not contain a fluorine atom and are low in cost.

Further, in the silylation reaction of diamine, an amine-based catalyst such as pyridine, piperidine, or triethylamine can be used to accelerate the reaction. This catalyst can be used as it is as a polymerization catalyst for the polyimide precursor.

4) Polyamic acid silyl ester (direct method)
A polyimide precursor is obtained by mixing the polyamic acid solution obtained by the method 1) with a silylating agent and stirring at 0 to 120 ° C., preferably 5 to 80 ° C. for 1 to 72 hours.

As the silylating agent used here, it is preferable to use a silylating agent that does not contain chlorine because it is not necessary to purify the silylated polyamic acid or the obtained polyimide. Examples of the silylating agent containing no chlorine atom include N, O-bis (trimethylsilyl) trifluoroacetamide, N, O-bis (trimethylsilyl) acetamide, and hexamethyldisilazane. N, O-bis (trimethylsilyl) acetamide and hexamethyldisilazane are particularly preferable because they do not contain a fluorine atom and are low in cost.

Since any of the above-mentioned production methods can be suitably carried out in an organic solvent, as a result, the varnish of the polyimide precursor of the present invention can be easily obtained.

Solvents used in preparing the polyimide precursor are, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide. Aprotonic solvents such as N, N-dimethylacetamide and N-methyl-2-pyrrolidone are preferable, but any kind of solvent can be used as long as the raw material monomer component and the resulting polyimide precursor are dissolved. Since it can be used without problems, it is not particularly limited to its structure. As the solvent, an amide solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α- Cyclic ester solvents such as methyl-γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, glycol solvents such as triethylene glycol, phenols such as m-cresol, p-cresol, 3-chlorophenol and 4-chlorophenol. System solvents, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide and the like are preferably adopted. In addition, other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, tetrahydrofuran. , Dimethoxyethane, diethoxyethane, dibutyl ether, diethylene glycol dimethyl ether, methylisobutylketone, diisobutylketone, cyclopentanone, cyclohexanone, methylethylketone, acetone, butanol, ethanol, xylene, toluene, chlorbenzene, turpen, mineral spirit, petroleum Nafsa-based solvents and the like can also be used. The solvent may be used in combination of a plurality of types.

In the present invention, the logarithmic viscosity of the polyimide precursor is not particularly limited, but the logarithmic viscosity in the N, N-dimethylacetamide solution having a concentration of 0.5 g / dL at 30 ° C. is 0.2 dL / g or more, more preferably 0. It is preferably 8.8 dL / g or more, particularly preferably 0.9 dL / g or more. When the logarithmic viscosity is 0.2 dL / g or more, the molecular weight of the polyimide precursor is high, and the mechanical strength and heat resistance of the obtained polyimide are excellent.

In the present invention, the polyimide precursor varnish (polyimide precursor solution composition) contains at least the polyimide precursor of the present invention and a solvent, and is tetra with respect to the total amount of the solvent, the tetracarboxylic acid component and the diamine component. It is preferable that the total amount of the carboxylic acid component and the diamine component is 5% by mass or more, preferably 10% by mass or more, and more preferably 15% by mass or more. In addition, it is usually preferable that it is 60% by mass or less, preferably 50% by mass or less. This concentration is a concentration substantially close to the solid content concentration due to the polyimide precursor, but if this concentration is too low, it becomes difficult to control the film thickness of the polyimide film obtained, for example, when manufacturing a polyimide film. Sometimes.

The solvent used for the varnish of the polyimide precursor of the present invention has no problem as long as the polyimide precursor is dissolved, and its structure is not particularly limited. Examples of the solvent for the varnish of the polyimide precursor include the same solvent as that used when preparing the above-mentioned polyimide precursor, and the solvent used when preparing the polyimide precursor is used as it is as the varnish of the polyimide precursor. Can be used as a solvent for. Further, if necessary, the solvent may be removed from the polyimide precursor solution prepared as described above, or the solvent may be added.

In the present invention, the viscosity (rotational viscosity) of the varnish of the polyimide precursor is not particularly limited, but the rotational viscosity measured at a temperature of 25 ° C. and a shear rate of 20 sec ^-1 using an E-type rotational viscometer is 0.01 to 1. 1000 Pa · sec is preferable, and 0.1 to 100 Pa · sec is more preferable. In addition, thixotropic properties can be imparted as needed. When the viscosity is in the above range, it is easy to handle when coating or forming a film, repelling is suppressed, and the leveling property is excellent, so that a good film can be obtained.

The polyimide precursor varnish of the present invention can be used as a chemical imidizing agent (acid anhydride such as acetic anhydride or an amine compound such as pyridine or isoquinolin), an antioxidant, a filler (inorganic particles such as silica, etc.), if necessary. ), Dyes, pigments, coupling agents such as silane coupling agents, primers, flame retardant materials, defoaming agents, leveling agents, polyimide control agents (fluid aids), release agents and the like.

The polyimide of the present invention can be suitably produced by subjecting the polyimide precursor of the present invention as described above to a dehydration ring closure reaction (imidization reaction). The imidization method is not particularly limited, and known thermal imidization or chemical imidization methods can be preferably applied.

Suitable examples of the form of the obtained polyimide include a film, a laminate of a polyimide film and another substrate, a coating film, a powder, beads, a molded body, a foam, and a varnish.

Hereinafter, an example of a polyimide film / base material laminate or a method for producing a polyimide film using the polyimide precursor of the present invention will be described. However, the method is not limited to the following.

The varnish of the polyimide precursor of the present invention is cast and coated on a substrate, and is used at 20 to 180 ° C., preferably 20 ° C. in vacuum, in an inert gas such as nitrogen, or in air using hot air or infrared rays. Dry in the temperature range of ~ 150 ° C. Next, the obtained polyimide precursor film was peeled off from the substrate or the polyimide precursor film was peeled off from the substrate, and the end portion of the film was fixed in a vacuum or in an inert gas such as nitrogen. Alternatively, a polyimide film / substrate laminate or a polyimide film can be produced by heating imidizing in air at a temperature of about 200 to 500 ° C., more preferably 250 to 450 ° C. using hot air or infrared rays. .. In order to prevent the obtained polyimide film from being oxidatively deteriorated, it is desirable that the heating imidization is performed in vacuum or in an inert gas. If the temperature of heating imidization is not too high, it may be performed in air.

Here, the base material is not particularly limited, and for example, a base material such as ceramic (glass, silicon, alumina), metal (copper, aluminum, stainless steel), and heat-resistant plastic film (polyimide film) can be used. In one embodiment, glass is preferable as the base material, and the polyimide film / glass base material laminate obtained by forming the polyimide film on the glass base material is preferably used for producing, for example, a substrate for a display. Be done.

Further, the imidization reaction of the polyimide precursor contains a dehydration cyclization reagent such as acetic anhydride in the presence of a tertiary amine such as pyridine or triethylamine instead of the heat imidization by the heat treatment as described above. It is also possible to carry out by a chemical treatment such as immersing in a solution. Further, these dehydration cyclization reagents are put into a varnish of a polyimide precursor in advance and stirred, and then cast and dried on a substrate to prepare a partially imidized polyimide precursor. It can also be obtained, and by further heat-treating it as described above, a polyimide film / substrate laminate or a polyimide film can be obtained.

The polyimide of the present invention also has a polyimide solution composition prepared by reacting a tetracarboxylic acid component and a diamine component in a solvent to prepare a solution composition (varnish) containing the polyimide of the present invention and heating or the like. It can also be suitably produced by removing the solvent from the substance.

Hereinafter, an example of a method for producing a polyimide solution composition (varnish containing polyimide) of the present invention and a method for producing a polyimide film / substrate laminate or a polyimide film using this polyimide solution composition will be described. However, the method is not limited to the following.

In the polyimide solution composition of the present invention, the tetracarboxylic acid component such as tetracarboxylic acid dianhydride and the diamine component are substantially equimolar, preferably the molar ratio of the diamine component to the tetracarboxylic acid component [diamine component. The number of moles / the number of moles of the tetracarboxylic acid component] is preferably 0.90 to 1.10, and more preferably 0.95 to 1.05.

More specifically, the diamine component is dissolved in a solvent, and the tetracarboxylic acid component such as tetracarboxylic acid dianhydride is gradually added while stirring the solution, and if necessary, preferably at room temperature to 80 ° C. After stirring in the range of 0.5 to 30 hours, the temperature is raised and the imidization reaction is carried out to obtain a polyimide solution. Imidization reaction can also be carried out by immediately raising the temperature after adding the tetracarboxylic acid component. It is also possible to reverse the order of addition of the diamine component and the tetracarboxylic acid component, and it is also possible to add the diamine component and the tetracarboxylic acid component to the solvent at the same time.

The imidization method is not particularly limited, and known thermal imidization or chemical imidization methods can be preferably applied. For example, a solution containing a tetracarboxylic acid component such as tetracarboxylic dianhydride and a diamine component is placed at a temperature in the range of 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 150 to 250 ° C., and 0.5 to 72. The imidization reaction can be carried out by reacting the tetracarboxylic acid component and the diamine component with stirring for a time. In the case of chemical imidization, a chemical imidizing agent (acid anhydride such as acetic anhydride or an amine compound such as pyridine, isoquinolin, or triethylamine) is added to the reaction solution to carry out the reaction. If necessary, an imidization catalyst or the like may be added to the reaction solution to carry out the reaction.

Further, the imidization reaction may be carried out while removing the water generated during the reaction.

When the molar ratio of the tetracarboxylic acid component to the diamine component is excessive, a carboxylic acid derivative in an amount substantially corresponding to the excess molar number of the diamine component is added as necessary, and the tetracarboxylic acid component and the diamine component are added. The molar ratio can be brought close to the equivalent amount. The carboxylic acid derivative here is a tetracarboxylic acid that does not substantially increase the viscosity of the polyimide solution, that is, does not substantially participate in the extension of the molecular chain, or a tricarboxylic acid that functions as a terminal terminator and its anhydride, a dicarboxylic acid. And its anhydride and the like are suitable.

The solvent used when preparing the polyimide solution is, for example, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, dimethyl sulfoxide, etc. Aprotic and aprotic solvents are preferable, and N, N-dimethylacetamide and N-methyl-2-pyrrolidone are particularly preferable, but any kind of solvent can be used as long as the raw material monomer component and the produced polyimide are dissolved. Since it can be used, it is not particularly limited to its structure. As the solvent, an amide solvent such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α- Cyclic ester solvents such as methyl-γ-butyrolactone, carbonate solvents such as ethylene carbonate and propylene carbonate, glycol solvents such as triethylene glycol, phenols such as m-cresol, p-cresol, 3-chlorophenol and 4-chlorophenol. System solvents, acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide and the like are preferably adopted. In addition, other common organic solvents such as phenol, o-cresol, butyl acetate, ethyl acetate, isobutyl acetate, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, tetrahydrofuran. , Dimethoxyethane, diethoxyethane, dibutyl ether, diethylene glycol dimethyl ether, methylisobutylketone, diisobutylketone, cyclopentanone, cyclohexanone, methylethylketone, acetone, butanol, ethanol, xylene, toluene, chlorbenzene, turpen, mineral spirit, petroleum Nafsa-based solvents and the like can also be used. The solvent may be used in combination of a plurality of types.

After the imidization reaction as described above, the obtained reaction solution is used as it is, or concentrated or diluted, and if necessary, additives and the like described below are added to obtain the polyimide solution composition of the present invention. Can be used. Alternatively, a soluble polyimide can be isolated from the obtained reaction solution, and the isolated polyimide can be added to a solvent to obtain the polyimide solution composition (varnish) of the present invention. Isolation of the polyimide can be performed, for example, by dropping or mixing a reaction solution containing the obtained soluble polyimide in a poor solvent such as water to precipitate (reprecipitate) the polyimide.

The polyimide solution composition (polyimide varnish) of the present invention contains at least the polyimide of the present invention and a solvent, and the polyimide is 5% by mass or more, preferably 10% by mass or more, based on the total amount of the solvent and the polyimide. The ratio is preferably 15% by mass or more, and particularly preferably 20% by mass or more. If this concentration is too low, it may be difficult to control the film thickness of the polyimide film obtained, for example, when manufacturing a polyimide film. In general, it is preferable that the polyimide content is 60% by mass or less, preferably 50% by mass or less.

As the solvent of the polyimide solution composition of the present invention, there is no problem as long as the polyimide is dissolved, and the structure thereof is not particularly limited. Examples of the solvent of the polyimide solution composition include the same solvent as that used when preparing the above-mentioned polyimide solution, and the solvent used when preparing the polyimide solution is used as it is as the solvent of the polyimide solution composition. can do. Further, if necessary, the solvent may be removed from the polyimide solution composition prepared as described above, or the solvent may be added.

In the present invention, the logarithmic viscosity of polyimide is not particularly limited, but the logarithmic viscosity in an N, N-dimethylacetamide solution having a concentration of 0.5 g / dL at 30 ° C. is 0.2 dL / g or more, more preferably 0.4 dL. It is preferably / g or more, particularly preferably 0.5 dL / g or more. When the logarithmic viscosity is 0.2 dL / g or more, the obtained polyimide is excellent in mechanical strength and heat resistance.

In the present invention, the viscosity (rotational viscosity) of the polyimide solution composition is not particularly limited, but the rotational viscosity measured at a temperature of 25 ° C. and a shear rate of 20 sec ^-1 using an E-type rotational viscometer is 0.01 to 1000 Pa. -Sec is preferable, and 0.1 to 100 Pa · sec is more preferable. In addition, thixotropic properties can be imparted as needed. When the viscosity is in the above range, it is easy to handle when coating or forming a film, repelling is suppressed, and the leveling property is excellent, so that a good film can be obtained.

The polyimide solution composition of the present invention can be used as an antioxidant, a filler (inorganic particles such as silica, etc.), a dye, a pigment, a coupling agent such as a silane coupling agent, a primer, a flame-retardant material, and a defoaming agent, if necessary. It can contain agents, leveling agents, rheology control agents (fluid aids), release agents and the like.

The polyimide of the present invention can be suitably obtained by removing the solvent from the polyimide solution composition prepared as described above. For example, a polyimide film / substrate laminate can be produced by casting and applying a polyimide solution composition on a substrate and heating the polyimide solution composition on the substrate to remove a solvent. .. The temperature of the heat treatment is not particularly limited, but is usually 80 to 500 ° C, preferably 100 to 500 ° C, and more preferably about 150 to 450 ° C. The heat treatment can be carried out in vacuum, in an inert gas such as nitrogen, or in air, but it is usually desirable to carry out the heat treatment in vacuum or in an inert gas. Then, the polyimide film can be manufactured by peeling the polyimide film formed on the substrate from the substrate.

Here, the base material is not particularly limited, and for example, a base material such as ceramic (glass, silicon, alumina), metal (copper, aluminum, stainless steel), and heat-resistant plastic film (polyimide film) can be used. In one embodiment, glass is preferable as the base material, and the polyimide film / glass base material laminate obtained by forming the polyimide film on the glass base material is preferably used for producing, for example, a substrate for a display. Be done.

Further, the polyimide solution composition is cast and applied on the substrate, the polyimide solution composition on the substrate is dried to the extent that it becomes self-supporting, and the obtained self-supporting film is peeled off from the substrate. The polyimide film can also be suitably produced by removing the solvent by heating the film in a fixed state. The drying conditions for producing the self-supporting film can be appropriately determined, and for example, the polyimide solution composition may be dried on the substrate in a temperature range of about 50 to 300 ° C. The temperature of the heat treatment of the self-supporting film is not particularly limited, but is usually 80 to 500 ° C, preferably 100 to 500 ° C, and more preferably about 150 to 480 ° C. Also in this method, the heat treatment can be carried out in vacuum, in an inert gas such as nitrogen, or in air, but it is usually desirable to carry out the heat treatment in vacuum or in an inert gas.

The form of polyimide obtained from the polyimide solution composition is not limited to a film or a laminate of a polyimide film and another base material, and a coating film, powder, beads, molded body, foam, or the like is also suitable. Can be listed in.

The polyimide of the present invention thus obtained has a linear thermal expansion coefficient between 100 and 250 ° C. when measured on a film having a thickness of 10 μm, but is not particularly limited, but is preferably 40 ppm / K or less, more preferably. It is preferably 35 ppm / K or less, more preferably 30 ppm / K or less, and particularly preferably 25 ppm / K or less. If the coefficient of linear thermal expansion is large, the difference in the coefficient of linear thermal expansion from that of a conductor such as metal is large, which may cause problems such as increased warpage when forming a circuit board.

The polyimide of the present invention also has a light transmittance at a wavelength of 400 nm when measured with a film having a thickness of 10 μm, but is not particularly limited, but is preferably 80% or more, more preferably 83% or more, and particularly preferably 85% or more. Is preferable. When a polyimide film is used for a display application or the like, if the light transmittance is low, it is necessary to strengthen the light source, which may cause a problem that energy is applied.

The polyimide of the present invention has a haze measured on a film having a thickness of 10 μm, but is not particularly limited, but is preferably 2% or less, more preferably 1.5% or less, and particularly preferably 1% or less. .. When a polyimide film is used for a display application or the like, if the haze is high, light may be scattered and the image may be blurred.

In the polyimide of the present invention, the thickness direction retardation (Rth) when measured with a film having a thickness of 10 μm is not particularly limited, but is preferably 500 nm or less, more preferably 350 nm or less, and particularly preferably 400 nm or less. preferable. When a polyimide film is used for a display application or the like, if the phase difference in the thickness direction is large, problems such as the color of transmitted light not being displayed correctly, color bleeding, and a narrow viewing angle may occur.

The film made of the polyimide of the present invention has a thickness of preferably 1 μm to 250 μm, more preferably 1 μm to 150 μm, still more preferably 1 μm to 100 μm, and particularly preferably 1 μm to 80 μm, although it depends on the application. When the polyimide film is used for light transmission, if the polyimide film is too thick, the light transmittance may decrease.

The polyimide film / base material laminate or the polyimide film obtained as described above can obtain a flexible conductive substrate by forming a conductive layer on one side or both sides thereof.

The flexible conductive substrate can be obtained, for example, by the following method. That is, as a first method, a conductive substance (metal or metal oxidation) is applied to the surface of the polyimide film by sputtering, vapor deposition, printing, etc. without peeling the polyimide film from the base material of the polyimide film / base material laminate. A conductive layer of an object, a conductive organic substance, a conductive carbon, etc.) is formed to produce a conductive laminate of a conductive layer / polyimide film / base material. After that, if necessary, the conductive layer / polyimide film laminate can be peeled off from the substrate to obtain a transparent and flexible conductive substrate made of the conductive layer / polyimide film laminate.

The second method is to peel the polyimide film from the base material of the polyimide film / base material laminate to obtain a polyimide film, and on the surface of the polyimide film, a conductive substance (metal or metal oxide, conductive organic substance, A conductive layer (such as conductive carbon) is formed in the same manner as in the first method, and is a transparent and flexible conductive layer composed of a conductive layer / polyimide film laminate or a conductive layer / polyimide film / conductive layer laminate. A sex substrate can be obtained.

In the first and second methods, if necessary, before forming a conductive layer on the surface of the polyimide film, a gas barrier layer such as water vapor or oxygen and light adjustment are performed by sputtering, vapor deposition, gel-sol method, or the like. An inorganic layer such as a layer may be formed.

Further, the conductive layer is preferably formed with a circuit by a method such as a photolithography method, various printing methods, or an inkjet method.

The substrate of the present invention thus obtained has a circuit of a conductive layer on the surface of a polyimide film made of the polyimide of the present invention, if necessary, via a gas barrier layer or an inorganic layer. This substrate is flexible, has excellent transparency, bendability, and heat resistance, and has a low coefficient of linear thermal expansion, so that it is easy to form a fine circuit. Therefore, this substrate can be suitably used as a substrate for a display, a touch panel, or a solar cell.

That is, a transistor (inorganic transistor, organic transistor) is further formed on this substrate by vapor deposition, various printing methods, an inkjet method, or the like to manufacture a flexible thin film transistor, and a liquid crystal element, an EL element, or a photoelectric device for a display device is manufactured. It is suitably used as an element.

Further, in the first method, after forming not only the conductive layer but also at least a part of the transistor and / or other elements and structures necessary for the device on the surface of the polyimide film / base material laminate, the surface is formed. The substrate may be peeled off.

Hereinafter, the present invention will be further described with reference to Examples and Comparative Examples. The present invention is not limited to the following examples.

In each of the following examples, the evaluation was performed by the following method.

<Evaluation of polyimide film>
[400 nm light transmittance]
Using an ultraviolet-visible spectrophotometer / V-650DS (manufactured by JASCO Corporation), the light transmittance of a polyimide film having a film thickness of 10 μm and a size of 5 cm square was measured at a wavelength of 400 nm.

[Haze]
Using a turbidity meter / NDH2000 (manufactured by Nippon Denshoku Kogyo Co., Ltd.), the haze of a polyimide film having a thickness of 10 μm and a size of 5 cm square was measured according to the JIS K7136 standard.

[Coefficient of linear thermal expansion (CTE)]
A polyimide film with a thickness of 10 μm is cut into strips with a width of 4 mm to make test pieces, and TMA / SS6100 (manufactured by SII Nanotechnology Co., Ltd.) is used. The temperature was raised to 500 ° C. in minutes. From the obtained TMA curve, the coefficient of linear thermal expansion from 100 ° C to 250 ° C was obtained.

[Film thickness direction phase difference (R _th )]
Using a polyimide film with a film thickness of 10 μm and a size of 5 cm square as a test piece, a phase difference measuring device (KOBRA-WR) manufactured by Oji Measuring Instruments Co., Ltd. was used to measure the phase difference of the film with an incident angle of 40 °. From the obtained phase difference, the phase difference in the thickness direction of the film having a film thickness of 10 μm was obtained.

[Tension modulus, fracture point elongation, fracture point stress]
The polyimide film is punched into a dumbbell shape of IEC-540 (S) standard to make a test piece (width: 4 mm), and using ORIENTEC's TENSILON, the chuck distance length is 30 mm, the tensile speed is 2 mm / min, and the initial tensile elastic modulus. , Break point elongation and break point stress were measured.

The abbreviations, purity, etc. of the raw materials used in each of the following examples are as follows.

[Diamine component]
TFMB: 2,2'-bis (trifluoromethyl) benzidine [purity: 99.83% (GC analysis)]
BAFL: 9,9-bis (4-aminophenyl) fluorene 4,4'-ODA: 4,4'-oxydianiline [purity: 99.9% (GC analysis)]
BABP: 4,4'-bis (4-aminophenoxy) biphenylSFXO: 4,4'-(spiro [fluorene-9,9'-xanthene] -3', 6'-diylbis (oxy)) dianiline [tetracarboxylic] Acid component]
CpODA: Norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'', 6,6''-tetracarboxylic acid dianhydride PMDA-H: 1, 2, , 4,5-Cyclohexanetetracarboxylic acid dianhydride [Purity: 99.9% (GC analysis)]
a-BPDA: 2,3,3', 4'-biphenyltetracarboxylic dianhydride

[solvent]
GBL: γ-Butyrolactone DMAc: N, N-dimethylacetamide

Table 1 shows the structural formulas of the tetracarboxylic acid component and the diamine component used in Examples and Comparative Examples.

[Example 1]
1.70 g (5.3 mmol) of TFMB and 7.40 g (21.3 mmol) of BAFL were placed in a reaction vessel substituted with nitrogen gas, and DMAc was added to the total mass of the charged monomer (total of diamine component and carboxylic acid component). 94.24 g was added in an amount of 25% by mass, and the mixture was stirred at room temperature for 1 hour. 10.20 g (26.5 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 2]
TFMB 3.00 g (9.4 mmol) and BAFL 6.06 g (17.4 mmol) were placed in a reaction vessel substituted with nitrogen gas, and DMAc was added to the total mass of the charged monomer (total of diamine component and carboxylic acid component). 94.48 g was added in an amount of 17% by mass, and the mixture was stirred at room temperature for 1 hour. 10.29 g (26.8 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 3]
TFMB 7.00 g (21.9 mmol) and BAFL 7.62 g (21.9 mmol) were placed in a reaction vessel substituted with nitrogen gas, and DMAc was added to the total mass of the charged monomer (total of diamine component and carboxylic acid component). 94.26 g was added in an amount of 25% by mass, and the mixture was stirred at room temperature for 1 hour. 16.80 g (43.7 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 4]
TFMB 7.00 g (21.9 mmol) and BAFL 6.23 g (17.9 mmol) were placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBL (DMAc: GBL = 1: 2 (mass ratio)) was placed. )) Is added in an amount of 95.44 g (DMAc is 31.81 g and GBL is 63.63 g) so that the total mass of the charged monomer (total of diamine component and carboxylic acid component) is 23% by mass, and the mixture is stirred at room temperature for 1 hour. bottom. 15.28 g (39.7 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 450 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent to obtain a colorless and transparent polyimide film / glass laminate. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 5]
TFMB 9.00 g (28.1 mmol) and BAFL 6.53 g (18.7 mmol) were placed in a reaction vessel substituted with nitrogen gas, and DMAc was added to the total mass of the charged monomer (total of diamine component and carboxylic acid component). 112.26 g was added in an amount of 23% by mass, and the mixture was stirred at room temperature for 1 hour. 18.00 g (46.8 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 430 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 6]
TFMB 9.00 g (28.1 mmol) and BAFL 4.20 g (12.0 mmol) were placed in a reaction vessel substituted with nitrogen gas, and DMAc was added to the total mass of the charged monomer (total of diamine component and carboxylic acid component). 95.85 g was added in an amount of 23% by mass, and the mixture was stirred at room temperature for 1 hour. 15.43 g (40.2 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 7]
10.00 g (31.2 mmol) of TFMB and 2.72 g (7.8 mmol) of BAFL were placed in a reaction vessel substituted with nitrogen gas, and DMAc was added to the total mass of the charged monomer (total of diamine component and carboxylic acid component). 92.82 g was added in an amount of 23% by mass, and the mixture was stirred at room temperature for 1 hour. 15.00 g (39.0 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 8]
TFMB 8.00 g (25.0 mmol), BAFL 2.90 g (8.3 mmol) and 4,4'-ODA 1.67 g (8.3 molimole) were placed in a reaction vessel substituted with nitrogen gas, and DMAc was placed. Was added with an amount of 95.66 g so that the total mass of the charged monomers (total of diamine component and carboxylic acid component) was 23% by mass, and the mixture was stirred at room temperature for 1 hour. 16.00 g (41.6 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 9]
In a reaction vessel substituted with nitrogen gas, 8.00 g (25.0 mmol) of TFMB, 4.35 g (12.5 mmol) of BAFL and 1.53 g (4.2 millimol) of BABP were placed, and DMAc was added to the total monomer. 100.07 g of an amount having a mass (total of diamine component and carboxylic acid component) of 23% by mass was added, and the mixture was stirred at room temperature for 1 hour. 16.00 g (41.6 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 10]
TFMB 6.00 g (18.7 mmol) and SFXO 8.38 g (15.3 mmol) were placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBL (DMAc: GBL = 1: 2 (mass ratio)) was placed. )) Is added in an amount of 82.44 g (DMAc is 27.48 g and GBL is 54.96 g) so that the total mass of the charged monomer (total of diamine component and carboxylic acid component) is 25% by mass, and the mixture is stirred at room temperature for 1 hour. bottom. 13.09 g (34.1 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-1.

[Example 11]
11.00 g (34.4 mmol) of TFMB and 5.13 g (14.7 mmol) of BAFL were placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBL (DMAc: GBL = 1: 2 (mass ratio)) was placed. )) To Add 87.29 g (29.10 g of DMAc and 58.19 g of GBL) in an amount such that the total mass of the charged monomer (total of diamine component and carboxylic acid component) is 25% by mass, and stir at room temperature for 1 hour. bottom. 4.72 g (12.3 mmol) of CpODA and 8.25 g (36.8 mmol) of PMDA-H were gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-2.

[Example 12]
10.00 g (31.2 mmol) of TFMB and 4.66 g (13.4 mmol) of BAFL were placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBL (DMAc: GBL = 1: 2 (weight ratio)) was placed. )) To Add 84.71 g (28.24 g of DMAc and 56.47 g of GBL) in an amount such that the total mass of the charged monomer (total of diamine component and carboxylic acid component) is 25% by mass, and stir at room temperature for 1 hour. bottom. 8.57 g (22.3 mmol) of CpODA and 5.00 g (22.3 mmol) of PMDA-H were gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-2.

[Example 13]
10.00 g (31.2 mmol) of TFMB and 4.66 g (13.4 mmol) of BAFL were placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBL (DMAc: GBL = 1: 2 (weight ratio)) was placed. )) To Add 90.06 g (DMAc: 30.02 g and GBL: 60.04 g) in an amount such that the total mass of the charged monomer (total of diamine component and carboxylic acid component) is 25% by mass, and stir at room temperature for 1 hour. bottom. 12.86 g (33.5 mmol) of CpODA and 2.50 g (11.1 mmol) of PMDA-H were gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-2.

[Example 14]
7.50 g (23.4 mmol) of TFMB and 8.16 g (23.4 mmol) of BAFL were placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBL (DMAc: GBL = 1: 2 (mass ratio)) was placed. )) Is added in an amount of 95.40 g (DMAc is 31.80 g and GBL is 63.60 g) so that the total mass of the charged monomer (total of diamine component and carboxylic acid component) is 25% by mass, and the mixture is stirred at room temperature for 1 hour. bottom. 13.50 g (35.1 mmol) of CpODA and 2.63 g (11.7 mmol) of PMDA-H were gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-2.

[Example 15]
TFMB 8.00 g (25.0 mmol) and BAFL 8.70 g (25.0 mmol) were placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBP (DMAc: GBL = 1: 2 (mass ratio)) was placed. )) Is added in an amount of 95.73 g (DMAc is 31.91 g and GBL is 63.82 g) so that the total mass of the charged monomer (total of diamine component and carboxylic acid component) is 25% by mass, and the mixture is stirred at room temperature for 1 hour. bottom. 13.50 g (25.0 mmol) of CpODA and 2.63 g (25.0 mmol) of PMDA-H were gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-2.

[Example 16]
15.00 g (46.8 mmol) of TFMB was placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBP (DMAc: GBL = 1: 2 (weight ratio)) was added to the total mass of the monomer (diamine component). And 90.00 g (DMAc is 30.00 g and GBL is 60.00 g) in an amount of 25% by mass (total of carboxylic acid components) was added, and the mixture was stirred at room temperature for 1 hour. 10.80 g (28.1 mmol) of CpODA and 4.20 g (18.7 mmol) of PMDA-H were gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 370 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-2.

[Example 17]
15.00 g (46.8 mmol) of TFMB was placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBP (DMAc: GBL = 1: 2 (weight ratio)) was added to the total mass of the monomer (diamine component). And 93.95 g (31.32 g of DMAc and 62.63 g of GBL) in an amount of 25% by mass (total of carboxylic acid components) was added, and the mixture was stirred at room temperature for 1 hour. 10.80 g (28.1 mmol) of CpODA and 5.51 g (18.7 mmol) of a-BPDA were gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-2.

[Comparative Example 1]
40.00 g (124.9 mmol) of TFMB was placed in a reaction vessel substituted with nitrogen gas, and a mixed solvent of DMAc and GBP (DMAc: GBL = 1: 2 (weight ratio)) was added to the total mass of the monomer (diamine component). And 264.04 g (DMAc: 88.01 g and GBL: 176.03 g) in an amount of 25% by mass (total of carboxylic acid components) was added, and the mixture was stirred at room temperature for 1 hour. 48.01 g (124.9 mmol) of CpODA was gradually added to this solution. The mixture was stirred at 70 ° C. for 3 hours and 160 ° C. for 7 hours to obtain a uniform and viscous polyimide solution. The imidization rate of the obtained polyimide solution was 95% or more.

The polyimide solution was applied to a glass substrate and heated from room temperature to 410 ° C. on the glass substrate as it was under a nitrogen atmosphere (oxygen concentration of 200 ppm or less) to remove the solvent, and a colorless and transparent polyimide film / glass laminate was obtained. Then, the obtained polyimide film / glass laminate was immersed in water, peeled off, and dried to obtain a polyimide film having a film thickness of 10 μm.

The results of measuring the characteristics of this polyimide film are shown in Table 2-2.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a polyimide having high transparency, a low coefficient of linear thermal expansion, and a small retardation in the thickness direction, and a precursor thereof. The polyimide obtained from the polyimide precursor of the present invention and the polyimide of the present invention have high transparency, a low coefficient of linear thermal expansion, easy to form a fine circuit, and a retardation in the thickness direction. Due to its small size, it can be suitably used for forming a substrate particularly for display applications.

Claims (7)

A polyimide precursor containing a repeating unit represented by the following general formula (1).
A ₁ of the following general formula (1) contains a tetravalent group represented by the following formula (A-1), and B ₁ of the following general formula (1) is represented by the following formula (B-1). Including the represented divalent group
Further, B ₁ of the following general formula (1) contains a divalent group containing a structure represented by the following formula (2), and A ₁ of the following general formula (1) is described as an optional component . A tetravalent group including a structure represented by the formula (2), a tetravalent group represented by the following formula (3) and / or a tetravalent group represented by the following formula (4).
The tetravalent group represented by the formula (A-1) in A ₁ 100 mol% of the general formula (1), the tetravalent group including the structure represented by the formula (2), and the formula (3). It is represented by the total content ratio of the tetravalent groups represented by the formula (4) and the tetravalent groups represented by the formula (4), and the formula (B-1) in B ₁ 100 mol% of the general formula (1). The sum of the total content ratios of the divalent groups and the divalent groups including the structure represented by the formula (2) is 120 mol% or more.
However, the tetravalent group represented by the formula (A-1), the tetravalent group including the structure represented by the formula (2), the tetravalent group represented by the formula (3), and the formula ( With respect to the total of the tetravalent groups represented by 4), the tetravalent group including the structure represented by the formula (2), the tetravalent group represented by the formula (3), and the formula (4). The ratio of the represented tetravalent group is 80 mol% or less, and
The divalent group including the structure represented by the formula (2) with respect to the total of the divalent groups represented by the formula (B-1) and the divalent group including the structure represented by the formula (2). A polyimide precursor having a group ratio of 20 mol% or more and 80 mol% or less.

(In the formula, A ₁ is a tetravalent group having an aromatic ring or an alicyclic structure, B ₁ is a divalent group having an aromatic ring or an alicyclic structure, and R ₁ and R ₂ are independent of each other. A hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. However, A ₁ and B ₁ contained in each repeating unit may be the same or different. .)

A polyimide containing a repeating unit represented by the following general formula (5).
A ₂ of the following general formula (5) contains a tetravalent group represented by the following formula (A-1), and B ₂ of the following general formula (5) is the following formula (B-1). Including the represented divalent group
Further, B ₂ of the following general formula (5) contains a divalent group containing a structure represented by the following formula (2), and A ₂ of the following general formula (5) is described as an optional component . A tetravalent group including a structure represented by the formula (2), a tetravalent group represented by the following formula (3) and / or a tetravalent group represented by the following formula (4).
The tetravalent group represented by the formula (A-1) in A ₂ 100 mol% of the general formula (5), the tetravalent group including the structure represented by the formula (2), and the formula (3). It is represented by the total content ratio of the tetravalent groups represented by the formula (4) and the tetravalent groups represented by the formula (4), and the formula (B-1) in B ₂ 100 mol% of the general formula (5). The sum of the total content ratios of the divalent groups and the divalent groups including the structure represented by the formula (2) is 120 mol% or more.
However, the tetravalent group represented by the formula (A-1), the tetravalent group including the structure represented by the formula (2), the tetravalent group represented by the formula (3), and the formula ( With respect to the total of the tetravalent groups represented by 4), the tetravalent group including the structure represented by the formula (2), the tetravalent group represented by the formula (3), and the formula (4). The ratio of the represented tetravalent group is 80 mol% or less, and
The divalent group including the structure represented by the formula (2) with respect to the total of the divalent groups represented by the formula (B-1) and the divalent group including the structure represented by the formula (2). A polyimide having a group ratio of 20 mol% or more and 80 mol% or less.

(In the formula, A ₂ is a tetravalent group having an aromatic ring or an alicyclic structure, and B ₂ is a divalent group having an aromatic ring or an alicyclic structure. However, it is included in each repeating unit. A ₂ and B ₂ may be the same or different.)

A polyimide obtained from the polyimide precursor according to claim 1. A varnish containing the polyimide precursor according to claim 1 or the polyimide according to claim 2. A polyimide film obtained by using the polyimide precursor according to claim 1 or a varnish containing the polyimide according to claim 2. A laminate comprising the polyimide according to claim 2 or 3, or the polyimide film according to claim 5 is formed on a glass substrate. A substrate for a display, a touch panel, or a solar cell, which comprises the polyimide according to claim 2 or 3, or the polyimide film according to claim 5.