KR20220104696A - Polyimide resins, polyimide varnishes and polyimide films - Google Patents

Abstract

A polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine, wherein the structural unit A is a structural unit derived from a compound represented by the following formula (a-1) (A-1) ), wherein the structural unit B is a structural unit derived from a compound represented by the following formula (b-1) (B-1), and a structural unit derived from a compound represented by the following formula (b-2) (B-2) -2) polyimide resin containing.

Description

Polyimide resins, polyimide varnishes and polyimide films

The present invention relates to polyimide resins, polyimide varnishes and polyimide films.

Various uses of polyimide resin are considered in the field|area, such as an electric and electronic component. For example, it is desired to replace a glass substrate used in an image display device such as a liquid crystal display or an OLED display with a plastic substrate for the purpose of weight reduction or flexibility of the device, and a polyimide film suitable as the plastic substrate Research is ongoing.

In an image display device, when light generated from a display element is emitted through a plastic substrate, colorless transparency is required for the plastic substrate. , touch panel, etc.) is required to have high optical isotropy (that is, low Rth) in addition to colorless transparency.

In order to satisfy the above-mentioned performance, development of polyimide resin of various compositions is performed. For example, in Patent Document 1, 3,3' as a diamine component for the purpose of obtaining a polyimide film having good solubility in a solvent and excellent processability and containing a polyamide having good solubility in a solvent and being colorless and transparent and excellent in toughness. A polyimide film comprising a structure composed of a combination of -diaminodiphenylsulfone with another specific diamine is disclosed.

International Publication No. 2016/158825

As described above, the polyimide film is required to have good optical properties such as colorless transparency and optical isotropy. In particular, optical isotropy is important for applications such as liquid crystal displays.

On the other hand, since polyimide has a rigid and strong molecular structure, fracture during the manufacture of films or when used in products with movable parts has been a problem. In order to suppress breakage, when a highly flexible component is introduced into the molecule or an additive is added to the resin, the optical properties are generally lowered. As described above, there has been a demand for a polyimide film having good optical properties and having ductility.

Furthermore, chemical resistance is also important. For example, when a varnish for forming the resin layer is applied to the polyimide film to form a separate resin layer (eg, color filter, resist) on the polyimide film, the polyimide film contains the varnish Resistance to the contained solvent is required. When the solvent resistance of a polyimide film is insufficient, there exists a possibility that the meaning as a board|substrate may be lost due to melt|dissolution and swelling of a film. However, in order to secure the optical properties as described above, the polyimide film had to be prepared as a solution, and it was difficult to achieve both of these properties.

As described above, there has been a demand for a polyimide resin capable of obtaining a polyimide film having flexibility and excellent chemical resistance while maintaining optical properties, particularly optical isotropy, of the obtained polyimide film.

Accordingly, an object of the present invention is to provide a polyimide resin, a polyimide varnish, and a polyimide film capable of forming a film having excellent optical isotropy and excellent flexibility and chemical resistance.

The inventors of the present invention have found that a polyimide resin containing a combination of a structural unit derived from a specific tetracarboxylic dianhydride and a structural unit derived from two specific diamines can solve the above problems, and completed the invention. came to do

That is, the present invention relates to the following <1> to <8>.

<1> A polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine, wherein the structural unit A is a structural unit derived from a compound represented by the following formula (a-1) ( A-1), wherein the structural unit B is a structural unit (B-1) derived from a compound represented by the following formula (b-1), and a structural unit derived from a compound represented by the following formula (b-2) A polyimide resin containing a unit (B-2).

[Formula 1]

<2> The ratio of the structural unit (B-1) in the structural unit B is 5-80 mol%, and the ratio of the structural unit (B-2) in the structural unit B is 20-95 mol%, the above The polyimide resin as described in <1>.

<3> the molar ratio [(B-1)/(B-2)] of the structural unit (B-1) to the structural unit (B-2) in the structural unit B is 5/95 to 80/20; The polyimide resin according to <1> or <2>.

<4> The structural unit A is derived from a structural unit (A-2-1) derived from a compound represented by the following formula (a-2-1), and a compound represented by the following formula (a-2-2) The polyimide resin according to any one of <1> to <3>, further comprising at least one selected from the group consisting of a structural unit (A-2-2).

[Formula 2]

<5> The structural unit B is derived from a structural unit (B-3-1) derived from a compound represented by the following formula (b-3-1), and a compound represented by the following formula (b-3-2) The polyimide resin according to any one of <1> to <4>, further comprising at least one selected from the group consisting of a structural unit (B-3-2).

[Formula 3]

(In formula (b-3-1), Z ¹ and Z ² each independently represent a divalent aliphatic group or a divalent aromatic group which may contain an oxygen atom, and R ¹ and R ² are each independently 1 represents a valent aromatic group or a monovalent aliphatic group, R ³ and R ⁴ each independently represent a monovalent aliphatic group, R ⁵ and R ⁶ each independently represent a monovalent aliphatic group or a monovalent aromatic group, m and n are Each independently represents an integer of 1 or more, and the sum of m and n represents an integer of 2 to 1000. However, at least one of R ¹ and R ² represents a monovalent aromatic group.)

<6> The polyimide resin according to <5>, wherein R ¹ and R ² in the formula (b-3-1) are phenyl groups.

<7> A polyimide varnish in which the polyimide resin according to any one of <1> to <6> is dissolved in an organic solvent.

<8> The polyimide film containing the polyimide resin in any one of said <1>-<6>.

According to the present invention, it is possible to provide a polyimide resin, a polyimide varnish, and a polyimide film capable of forming a film having excellent optical isotropy and excellent flexibility and chemical resistance.

[Polyimide resin]

The polyimide resin of the present invention is a polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine, wherein the structural unit A is a compound represented by the following formula (a-1) A structural unit (B-1) derived from a compound including a structural unit (A-1) derived from, wherein the structural unit B is represented by the following formula (b-1), A structural unit (B-2) derived from a compound is included.

Suzy.

[Formula 4]

On the other hand, it is not clear why the polyimide resin of the present invention has excellent flexibility and chemical resistance while maintaining optical isotropy. It is considered to be excellent in flexibility and chemical resistance while maintaining isotropy. Among these, since it has a structural unit derived from the small diamine which has an alicyclic structure in the structure, an imide group concentration is high and it is thought that it is very excellent in chemical-resistance while maintaining optical isotropy.

<composition unit A>

Structural unit A is a structural unit derived from the tetracarboxylic dianhydride which occupies for polyimide resin.

The structural unit A includes a structural unit (A-1) derived from a compound represented by the following formula (a-1).

[Formula 5]

The compound represented by Formula (a-1) is 4,4'- oxydiphthalic anhydride.

When the structural unit A includes the structural unit (A-1), the chemical resistance and toughness of the film can be improved.

The proportion of the structural unit (A-1) in the structural unit A is preferably 40 mol% or more, more preferably 50 mol% or more, still more preferably 55 mol% or more, and still more preferably is 60 mol% or more. From a viewpoint of the toughness of a film, More preferably, it is 70 mol% or more. The upper limit of the ratio of the structural unit (A-1) is not particularly limited, that is, it is 100 mol%. The constituent unit A may consist of only the constituent unit (A-1).

The structural unit A may include structural units other than the structural unit (A-1).

The structural unit A is, in addition to the structural unit (A-1), from the viewpoint of heat resistance, a structural unit (A-2-1) derived from a compound represented by the following formula (a-2-1), and the following formula ( It is preferable that the structural unit (A-2) which is at least 1 selected from the group which consists of structural units (A-2-2) derived from the compound represented by a-2-2) is included. That is, the structural unit (A-2-1) and the structural unit (A-2-2) are collectively referred to as the structural unit (A-2).

[Formula 6]

The compound represented by formula (a-2-1) is 1,2,4,5-cyclohexanetetracarboxylic dianhydride.

The compound represented by the formula (a-2-2) is norbornane-2-spiro-α-cyclopentanone-α′-spiro-2′′-novonane-5,5′′,6,6′′ -Tetracarboxylic acid dianhydride.

The proportion of the structural unit (A-2) in the structural unit A is preferably 10 to 50 mol%, more preferably 15 to 45 mol%, from the viewpoint of improving heat resistance, chemical resistance, and optical isotropy. , more preferably 20 to 40 mol%.

When the structural unit A contains the structural unit (A-2), the molar ratio [(A-1)/(A-2) of the structural unit (A-1) to the structural unit (A-2) in the structural unit A )], from the viewpoint of improving heat resistance, chemical resistance and optical isotropy, preferably 50/50 to 90/10, more preferably 55/45 to 85/15, still more preferably 60/40 to It is 80/20.

The structural unit A may include structural units other than the structural unit (A-1) and the structural unit (A-2). Although it does not specifically limit as tetracarboxylic dianhydride which gives such a structural unit, Pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 9,9'-bis( Aromatic tetracarboxylic dianhydrides such as 3,4-dicarboxyphenyl)fluorene dianhydride and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (provided that they are represented by the formula (a-1) compounds are excluded); Alicyclic tetracarboxylic dianhydride such as 1,2,3,4-cyclobutanetetracarboxylic dianhydride (however, except for compounds represented by formulas (a-2-1) and (a-2-2) do); and aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butanetetracarboxylic dianhydride.

On the other hand, in the present specification, aromatic tetracarboxylic dianhydride means tetracarboxylic dianhydride containing one or more aromatic rings, and alicyclic tetracarboxylic dianhydride includes one or more alicyclic rings and also aromatic rings. It means tetracarboxylic dianhydride not containing, and aliphatic tetracarboxylic dianhydride means tetracarboxylic dianhydride containing neither an aromatic ring nor an alicyclic ring.

The number of structural units arbitrarily included in the structural unit A may be one, or 2 or more types may be sufficient as them.

<Constituent Unit B>

The structural unit B is a structural unit derived from the diamine occupied in the polyimide resin, and is represented by a structural unit (B-1) derived from a compound represented by the following formula (b-1) and a following formula (b-2) It contains the structural unit (B-2) derived from the compound used.

[Formula 7]

The compound represented by formula (b-1) is 4,4'-diamino-2,2'-bistrifluoromethyldiphenyl ether.

When the structural unit B includes the structural unit (B-1), the optical isotropy and colorless transparency of the film can be improved.

The compound represented by the formula (b-2) is bis(aminomethyl)cyclohexane, and specific examples thereof include 1,3-bis(aminomethyl)cyclohexane represented by the following formula (b-2a), the following The 1, 4-bis (aminomethyl) cyclohexane represented by a formula (b-2b) is mentioned.

[Formula 8]

From the viewpoint of organic solvent resistance and heat resistance, the cis:trans ratio of the compound represented by the formula (b-2) is preferably 0:100 to 80:20, more preferably 0.1:99.9 to 70:30, and 0.5 :99.5-60:40 are more preferable, and 1:99-20:80 are still more preferable.

When the structural unit B includes the structural unit (B-2), optical isotropy, flexibility, and chemical resistance of the film can be improved.

The proportion of the structural unit (B-1) in the structural unit B is preferably 5-80 mol%, more preferably 10-70 mol%, and still more preferably 30-60 mol%.

The proportion of the structural unit (B-2) in the structural unit B is preferably 20 to 95 mol%, more preferably 30 to 90 mol%, and still more preferably 40 to 70 mol%.

The ratio of the total of the structural units (B-1) and (B-2) in the structural unit B is preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 90 mol% or more. % or more The upper limit of the ratio of the sum total of structural units (B-1) and (B-2) is not specifically limited, That is, it is 100 mol%. The structural unit B may consist of only the structural unit (B-1) and the structural unit (B-2).

The molar ratio [(B-1)/(B-2)] of the structural unit (B-1) to the structural unit (B-2) in the structural unit B is preferable from the viewpoint of improving optical isotropy and chemical resistance. Preferably it is 5/95-80/20, More preferably, it is 10/90-70/30, More preferably, it is 30/70-60/40.

The structural unit B may include structural units other than the structural units (B-1) and (B-2).

The structural unit B is, in addition to the structural units (B-1) and (B-2), a structural unit derived from a compound represented by the following formula (b-3-1) (B-3-1), the following formula ( It is preferable to contain the structural unit (B-3) which is at least 1 selected from the group which consists of structural units (B-3-2) derived from the compound represented by b-3-2). That is, the structural unit (B-3-1) and the structural unit (B-3-2) are collectively referred to as the structural unit (B-3). Among these, it is preferable that the structural unit B further contains the structural unit (B-3-1) derived from the compound represented by the following formula (b-3-1).

[Formula 9]

In the formula (b-3-1), Z ¹ and Z ² each independently represent a divalent aliphatic group or a divalent aromatic group which may contain an oxygen atom, and R ¹ and R ² are each independently a monovalent an aromatic group or a monovalent aliphatic group, R ³ and R ⁴ each independently represent a monovalent aliphatic group, R ⁵ and R ⁶ each independently represent a monovalent aliphatic group or a monovalent aromatic group, m and n are each Independently represents an integer of 1 or more, and the sum of m and n represents an integer of 2 to 1000. However, at least one of R ¹ and R ² represents a monovalent aromatic group.

On the other hand, in formula (b-3-1), two or more different repeating units described in [ ] are repeated in any form and order in random, alternating or block, respectively, regardless of the order of [ ]. there may be

In the formula (b-3-1), the divalent aliphatic group or the divalent aromatic group in Z ¹ and Z ² may be substituted with a fluorine atom. Examples of the divalent aliphatic group include a divalent saturated or unsaturated aliphatic group having 1 to 20 carbon atoms and an aliphatic group containing an oxygen atom. As for carbon number of a divalent aliphatic group, 3-20 are preferable.

Examples of the divalent saturated aliphatic group include an alkylene group having 1 to 20 carbon atoms, for example, a methylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, an octamethylene group, and a decamethylene group. , a dodecamethylene group, and the like can be exemplified.

Examples of the divalent unsaturated aliphatic group include an alkylene group having 2 to 20 carbon atoms, and examples thereof include a vinylene group, a propenylene group, and an alkylene group having an unsaturated double bond at the terminal.

Examples of the aliphatic group containing an oxygen atom include an alkyleneoxy group and an aliphatic group having an ether bond.

As an alkyleneoxy group, a propyleneoxy group, trimethyleneoxy group, etc. can be illustrated.

As a divalent aromatic group, a C6-C20 arylene group, a C7-20 aralkylene group, etc. can be illustrated. Specific examples of the arylene group having 6 to 20 carbon atoms in Z ¹ and Z ² include o-phenylene group, m-phenylene group, p-phenylene group, 4,4′-biphenylrylene group, 2,6- A naphthylene group etc. are mentioned.

As Z< ¹ > and Z< ² >, a trimethylene group and p-phenylene group are especially preferable, and a trimethylene group is more preferable.

In the formula (b-3-1), examples of the monovalent aliphatic group for R ¹ to R ⁶ include a monovalent saturated or unsaturated aliphatic group. As monovalent saturated aliphatic group, a C1-C22 alkyl group is mentioned, For example, a methyl group, an ethyl group, a propyl group, etc. can be illustrated. As a monovalent unsaturated aliphatic group, a C2-C22 alkenyl group is mentioned, For example, a vinyl group, a propenyl group, etc. can be illustrated. These groups may be substituted with a fluorine atom.

Examples of the monovalent aromatic group for R ¹ , R ² , R ⁵ and R ⁶ in the formula (b-3-1) include an aryl group having 6 to 20 carbon atoms, an aryl group having 7 to 30 carbon atoms and further substituted with an alkyl group. , an aralkyl group having 7 to 30 carbon atoms, and the like. As a monovalent aromatic group, an aryl group is preferable and a phenyl group is more preferable.

Although at least one of R ¹ and R ² represents a monovalent aromatic group, it is preferable that both R ¹ and R ² are a monovalent aromatic group, and it is more preferable that both R ¹ and R ² are a phenyl group.

As R ³ and R ⁴ , an alkyl group having 1 to 6 carbon atoms is preferable, and a methyl group is more preferable.

As R ⁵ and R ⁶ , a monovalent aliphatic group is preferable, and a methyl group is more preferable.

As described above, among the compounds represented by the formula (b-3-1), the compound represented by the following formula (b-3-11) is preferable.

[Formula 10]

(In formula (b-3-11), m and n have the same meaning as m and n in formula (b-3-1), and their preferred ranges are also the same.)

In the formulas (b-3-1) and (b-3-11), m represents the repeating number of the siloxane unit to which at least one monovalent aromatic group is bonded, in the formulas (b-3-1) and (b-3-1) In b-3-11), n represents the number of repeats of the siloxane unit to which the monovalent aliphatic group is bonded.

In formulas (b-3-1) and (b-3-11), m and n each independently represent an integer of 1 or more, and the sum of m and n (m+n) represents an integer of 2 to 1000. indicates. The sum of m and n becomes like this. Preferably it is an integer of 3-500, More preferably, it is 3-100, More preferably, it represents the integer of 3-50.

The ratio of m/n in the formulas (b-3-1) and (b-3-11) is preferably 5/95 to 50/50, more preferably 10/90 to 40/60, More preferably, it is 20/80-30/70.

The functional group equivalent (amine equivalent) of the compound represented by the formula (b-3-1) is preferably 150 to 5,000 g/mol, more preferably 400 to 4,000 g/mol, still more preferably 500 to 3,000 g /mol.

In addition, functional group equivalent means the mass of the compound represented by Formula (b-3-1) per 1 mol of functional group (amino group).

Among the compounds represented by the formula (b-3-1), commercially available compounds include "X-22-9409", "X-22-1660B", "X-22" manufactured by Shin-Etsu Chemical Co., Ltd. -161A", "X-22-161B", etc. are mentioned.

When the structural unit B includes the structural unit (B-3-1), colorless transparency, optical isotropy and flexibility of the film can be improved.

Formula (b-3-2) is 4,4'- diaminodiphenyl sulfone. When the structural unit B includes the structural unit (B-3-2), colorless transparency, toughness and chemical resistance of the film can be improved.

When the structural unit B includes the structural unit (B-1), the structural unit (B-2) and the structural unit (B-3), the structural unit (B-1) and the structural unit (B) in the structural unit B The ratio of the total of -2) is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and the structural unit (B-3) in the structural unit B ), Preferably it is 0.1-30 mol%, More preferably, it is 1-25 mol%, More preferably, it is 2-20 mol%, More preferably, it is 3-15 mol%.

The ratio of the total of the structural unit (B-1), the structural unit (B-2) and the structural unit (B-3) in the structural unit B is preferably 80 mol% or more, more preferably 90 mol % or more, particularly preferably 99 mol% or more. The upper limit of the ratio of the total of the structural unit (B-1), the structural unit (B-2) and the structural unit (B-3) is not particularly limited, that is, it is 100 mol%. The structural unit B may consist of only the structural unit (B-1), the structural unit (B-2), and the structural unit (B-3).

When structural unit B includes structural unit (B-1), structural unit (B-2) and structural unit (B-3-1), structural unit (B-1) and structural unit in structural unit B The ratio of the total of (B-2) is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and the structural unit (B) in the structural unit B The ratio of -3-1) is preferably 0.1 to 30 mol%, more preferably 1 to 25 mol%, still more preferably 2 to 20 mol%, still more preferably 3 to 15 mol% %, and even more preferably 3 to 10 mol%.

The ratio of the total of the structural unit (B-1), the structural unit (B-2) and the structural unit (B-3-1) in the structural unit B is preferably 80 mol% or more, more preferably It is 90 mol% or more, Especially preferably, it is 99 mol% or more. The upper limit of the ratio of the total of the structural unit (B-1), the structural unit (B-2) and the structural unit (B-3-1) is not particularly limited, that is, it is 100 mol%. The structural unit B may consist of only the structural unit (B-1), the structural unit (B-2), and the structural unit (B-3-1).

When structural unit B includes structural unit (B-1), structural unit (B-2) and structural unit (B-3-2), structural unit (B-1) and structural unit in structural unit B The ratio of the total of (B-2) is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and the structural unit (B) in the structural unit B The ratio of -3-2) is preferably 2 to 30 mol%, more preferably 3 to 30 mol%, further preferably 10 to 30 mol% from the viewpoint of colorless transparency, toughness and chemical resistance of the film. It is mol%, More preferably, it is 15-30 mol%, More preferably, it is 15-25 mol%.

The ratio of the total of the structural unit (B-1), the structural unit (B-2) and the structural unit (B-3-2) in the structural unit B is preferably 80 mol% or more, more preferably It is 90 mol% or more, Especially preferably, it is 99 mol% or more. The upper limit of the ratio of the total of the structural unit (B-1), the structural unit (B-2) and the structural unit (B-3-2) is not particularly limited, that is, it is 100 mol%. The structural unit B may consist of only the structural unit (B-1), the structural unit (B-2), and the structural unit (B-3-2).

The structural unit (B-3) may be only the structural unit (B-3-1), or only the structural unit (B-3-2), or the structural unit (B-3-1) and the structural unit (B-) 3-2) may be a combination.

The structural unit B may include structural units other than the structural units (B-1), (B-2) and (B-3). The diamine imparting such a structural unit is not particularly limited, but 1,4-phenylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene, 2,2'-dimethylbiphenyl-4,4' -Diamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-diaminobenzanilide , 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine, α,α′-bis(4-aminophenyl)-1,4- Diisopropylbenzene, N,N'-bis(4-aminophenyl)terephthalamide, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2-bis[4-(4-aminophenoxy) Aromatic diamines such as phenyl]propane, 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, and 9,9-bis(4-aminophenyl)fluorene (provided that The compound represented by b-1), the compound represented by the formula (b-3-1), and the compound represented by the formula (b-3-2) are excluded); alicyclic diamine (however, the compound represented by formula (b-2) is excluded); and aliphatic diamines such as ethylenediamine and hexamethylenediamine.

On the other hand, in the present specification, aromatic diamine means a diamine containing one or more aromatic rings, and alicyclic diamine means a diamine containing one or more alicyclic rings and does not contain an aromatic ring, and aliphatic diamine is It means diamine which contains neither an aromatic ring nor an alicyclic ring.

The number of structural units other than the structural units (B-1), (B-2) and (B-3) arbitrarily included in the structural unit B may be one, or two or more types may be sufficient as them.

<Characteristics of polyimide resin>

The number average molecular weight of polyimide resin becomes like this. From a viewpoint of the mechanical strength of the polyimide film obtained, Preferably it is 5,000-300,000. In addition, the number average molecular weight of a polyimide resin can be calculated|required from the standard polymethylmethacrylate (PMMA) conversion value by gel filtration chromatography measurement, for example.

The polyimide resin may contain a structure other than the polyimide chain (a structure in which the structural unit A and the structural unit B are imide-bonded). As structures other than the polyimide chain which can be contained in polyimide resin, the structure etc. containing an amide bond are mentioned, for example.

The polyimide resin preferably contains, as a main structure, a polyimide chain (a structure in which the structural unit A and the structural unit B are imide bonds). Therefore, the proportion of the polyimide chain in the polyimide resin is preferably 50 mass % or more, more preferably 70 mass % or more, still more preferably 90 mass % or more, particularly preferably 99 mass % or more. More than that.

The polyimide resin composition of the present invention containing the polyimide resin can form a film excellent in colorless transparency, optical isotropy and chemical resistance, and suitable physical property values of the film are as follows.

When a total light transmittance is set as the film of 10 micrometers in thickness, Preferably it is 88 % or more, More preferably, it is 88.5 % or more, More preferably, it is 89 % or more.

The yellow index (YI) is preferably 4.5 or less, more preferably 3.0 or less, still more preferably 2.0 or less, still more preferably 1.5 or less when a film having a thickness of 10 µm is used.

The absolute value of the thickness retardation Rth is preferably 70 nm or less, more preferably 60 nm or less, and still more preferably 50 nm or less when a film having a thickness of 10 µm is obtained.

In addition, the film that can be formed using the polyimide resin has good mechanical properties and heat resistance, and has the following suitable physical properties.

The film that can be formed by using the polyimide resin of the present invention has good mechanical properties and heat resistance, and has the following suitable physical properties.

The tensile strength is preferably 70 MPa or more, more preferably 80 MPa or more, and still more preferably 90 MPa or more.

The tensile modulus of elasticity is preferably 2.0 GPa or more, more preferably 2.5 GPa or more, and still more preferably 3.0 GPa or more.

The elongation at break is preferably 8% or more, more preferably 10% or more, and still more preferably 15% or more.

The glass transition temperature (Tg) is preferably 200°C or higher, more preferably 230°C or higher, and still more preferably 250°C or higher.

In addition, the above-mentioned physical property value in this invention can be specifically measured by the method as described in an Example.

<Method for producing polyimide resin>

In this invention, polyimide resin is a tetracarboxylic acid component containing the compound which provides the above-mentioned structural unit (A-1), and the compound which provides the above-mentioned structural unit (B-1), and the above-mentioned It can be prepared by reacting a diamine component containing a compound giving one structural unit (B-2).

Although the compound represented by Formula (a-1) is mentioned as a compound which provides a structural unit (A-1), It is not limited to it, It may be a derivative|guide_body within the range which gives the same structural unit. Examples of the derivative include tetracarboxylic acid corresponding to tetracarboxylic dianhydride represented by formula (a-1) (ie, 4,4'-oxydiphthalic acid), and alkyl esters of tetracarboxylic acid. . Among these, the tetracarboxylic dianhydride represented by Formula (a-1) is preferable.

The tetracarboxylic acid component contains preferably 40 mol% or more of the compound providing the structural unit (A-1), more preferably 50 mol% or more, further preferably 70 mol% or more. . The upper limit of content of the compound which provides a structural unit (A-1) is not specifically limited, That is, it is 100 mol%. The tetracarboxylic acid component may consist only of a compound giving the structural unit (A-1).

The tetracarboxylic acid component can also contain compounds other than the compound which provides a structural unit (A-1).

The tetracarboxylic acid component may further contain the compound which provides a structural unit (A-2) in addition to the compound which provides a structural unit (A-1).

Examples of the compound providing the structural unit (A-2) include, but are not limited to, the compound represented by the formula (a-2-1) and the compound represented by the formula (a-2-2), It may be a derivative thereof within the range giving the same structural unit. As said derivative, the tetracarboxylic acid corresponding to the compound represented by Formula (a-2-1) and Formula (a-2-2), and the alkylester of this tetracarboxylic acid are mentioned. As a compound which provides a structural unit (A-2), the compound (ie, a dianhydride) represented by a formula (a-2-1) and a formula (a-2-2) is preferable.

When the tetracarboxylic acid component contains a compound providing the structural unit (A-2), the tetracarboxylic acid component contains preferably 10 to 50 mol% of the compound providing the structural unit (A-2), , More preferably, it contains 15-45 mol%, More preferably, it contains 20-40 mol%.

Compounds other than the compound providing the structural unit (A-1) arbitrarily contained in the tetracarboxylic acid component are not limited to the compound providing the structural unit (A-2). As such optional compounds, the above-mentioned aromatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aliphatic tetracarboxylic dianhydride, and derivatives thereof (tetracarboxylic acid, alkyl esters of tetracarboxylic acid, etc.) can be heard

The number of compounds other than the compound which provides the structural unit (A-1) and the compound which provides the structural unit (A-2) which are contained arbitrarily in a tetracarboxylic-acid component may be one, or 2 or more types may be sufficient as them.

Although the compound represented by Formula (b-1) is mentioned as a compound which provides a structural unit (B-1), It is not limited to it, It may be a derivative|guide_body within the range which gives the same structural unit. As this derivative, the diisocyanate corresponding to the compound (diamine) represented by Formula (b-1) is mentioned. Among these, the compound (namely, diamine) represented by a formula (b-1) is preferable.

Similarly, examples of the compound providing the structural unit (B-2) include compounds represented by the formula (b-2), but it is not limited thereto, and may be a derivative thereof within the range giving the same structural unit. . As this derivative, the diisocyanate corresponding to the compound (diamine) represented by Formula (b-2) is mentioned. As a compound which provides a structural unit (B-2), the compound (ie, diamine) represented by Formula (b-2) is preferable.

The diamine component contains, preferably 5 to 80 mol%, more preferably 10 to 70 mol%, further preferably 30 to 60 mol% of the compound giving the structural unit (B-1). do.

The diamine component contains preferably 20 to 95 mol%, more preferably 30 to 90 mol%, and still more preferably 40 to 70 mol% of the compound giving the structural unit (B-2). do.

The diamine component contains, in total, preferably 50 mol% or more, more preferably 70 mol% or more, of the compound providing the structural unit (B-1) and the compound giving the structural unit (B-2) in total. and more preferably 90 mol% or more. The upper limit of content of the sum total of the compound which provides a structural unit (B-1), and the compound which provides a structural unit (B-2) is not specifically limited, ie, it is 100 mol%. The diamine component may consist only of a compound providing the structural unit (B-1) and a compound providing the structural unit (B-2).

The diamine component may contain compounds other than the compound providing the structural unit (B-1) and the compound providing the structural unit (B-2).

A diamine component may further contain the compound which provides a structural unit (B-3) in addition to the compound which provides a structural unit (B-1), and the compound which provides a structural unit (B-2).

Examples of the compound giving the structural unit (B-3) include, but are not limited to, the compound represented by the formula (b-3-1) and the compound represented by the formula (b-3-2), but the same It may be a derivative thereof within the range that provides a structural unit. As this derivative, the diisocyanate corresponding to the diamine represented by a formula (b-3-1), and the diisocyanate corresponding to the diamine represented by a formula (b-3-2) are mentioned. As the compound giving the structural unit (B-3), a compound represented by the formula (b-3-1) and a compound represented by the formula (b-3-2) (ie, diamine) are preferable.

As the compound giving the structural unit (B-3), only the compound represented by the formula (b-3-1) or only the compound represented by the formula (b-3-2) may be used, or the compound represented by the formula (b- It may be a combination of the compound represented by 3-1) and the compound represented by the formula (b-3-2).

When the diamine component contains a compound providing the structural unit (B-3), the diamine component contains the compound providing the structural unit (B-3), preferably 0.1 to 30 mol%, more preferably 1 to 25 mol%, more preferably 5 to 25 mol%.

When the diamine component contains a compound providing a structural unit (B-3), the diamine component is a compound providing a structural unit (B-1), a compound providing a structural unit (B-2), and a structural unit ( B-3) in total, Preferably it contains 80 mol% or more, More preferably, it contains 90 mol% or more, More preferably, it contains 99 mol% or more. The upper limit of the content of the total of the compound giving the structural unit (B-1), the compound giving the structural unit (B-2), and the compound giving the structural unit (B-3) is not particularly limited, that is, 100 is mole %. The diamine component may consist only of a compound providing a structural unit (B-1), a compound providing a structural unit (B-2), and a compound providing a structural unit (B-3).

Compounds other than the compound providing the structural unit (B-1) and the compound providing the structural unit (B-2), which are arbitrarily included in the diamine component, are not limited to the compound providing the structural unit (B-3). As such arbitrary compounds, the aromatic diamines, alicyclic diamines, and aliphatic diamines mentioned above, and those derivatives (diisocyanate etc.) are mentioned.

The number of compounds other than the compound which provides the structural unit (B-1) and the compound which provides a structural unit (B-2) which are contained arbitrarily in a diamine component may be one, or 2 or more types may be sufficient as it.

In the present invention, it is preferable that the input ratio of the tetracarboxylic acid component and the diamine component used in the production of the polyimide resin is 0.9 to 1.1 moles of the diamine component per 1 mole of the tetracarboxylic acid component.

Further, in the present invention, for the production of the polyimide resin, an end-blocking agent may be used in addition to the tetracarboxylic acid component and the diamine component described above. As the terminal blocker, monoamines or dicarboxylic acids are preferable. The amount of the terminal blocker to be introduced is preferably 0.0001 to 0.1 mol, more preferably 0.001 to 0.06 mol, based on 1 mol of the tetracarboxylic acid component. Monoamine end caps include, for example, methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine , 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, etc. are mentioned, and benzylamine and aniline are preferable. As the dicarboxylic acid end capping agent, dicarboxylic acids are preferable, and a part thereof may be ring-closed. For example, phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenonedicarboxylic acid, 3,4-benzophenonedicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, Cyclopentane-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, etc. are mentioned, Phthalic acid and phthalic anhydride are preferable.

There is no restriction|limiting in particular in the method of making the above-mentioned tetracarboxylic-acid component and diamine component react, A well-known method can be used.

As a specific reaction method, (1) a tetracarboxylic acid component, a diamine component, and a reaction solvent are put into a reactor, stirred at 0 to 80° C. for 0.5 to 30 hours, and then the temperature is raised to perform imidization reaction, ( 2) After dissolving the diamine component and the reaction solvent in a reactor, the tetracarboxylic acid component is added, and if necessary, the mixture is stirred at room temperature 0 to 80° C. for 0.5 to 30 hours, and then the temperature is raised to perform imidization reaction. , (3) a method in which a tetracarboxylic acid component, a diamine component, and a reaction solvent are put into a reactor, and the temperature is immediately raised to carry out an imidization reaction, and the like.

The reaction solvent used for manufacture of a polyimide resin should just be what can melt|dissolve the polyimide produced|generated without inhibiting imidation reaction. For example, an aprotic solvent, a phenol type solvent, an ether type solvent, a carbonate type solvent, etc. are mentioned.

Specific examples of the aprotic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone (NMP), N-methylcaprolactam, 1,3-dimethyl Amide solvents such as imidazolidinone and tetramethylurea, Lactone solvents such as γ-butyrolactone (GBL) and γ-valerolactone, Phosphorus-containing solvents such as hexamethylphosphoricamide and hexamethylphosphine triamide Amide solvents, sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide and sulfolane, ketone solvents such as acetone, cyclohexanone, and methylcyclohexanone, amine solvents such as picoline and pyridine, acetic acid (2-methyl Ester solvents, such as oxy-1-methylethyl), etc. are mentioned.

Specific examples of the phenolic solvent include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6 -xylenol, 3,4-xylenol, 3,5-xylenol, etc. are mentioned.

Specific examples of the ether-based solvent include 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane, beads [2-(2-methyl) ethoxy)ethyl]ether, tetrahydrofuran, 1,4-dioxane, and the like.

Further, specific examples of the carbonate-based solvent include diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, and propylene carbonate.

Among the above reaction solvents, aprotic solvents are preferable, and amide solvents and lactone solvents are more preferable. In addition, the above reaction solvents may be used alone or in mixture of two or more.

In the imidization reaction, it is preferable to use a Dean-Stark apparatus or the like to perform the reaction while removing water generated during production. By performing such operation, polymerization degree and imidation rate can be raised more.

In the above imidation reaction, a known imidation catalyst can be used. Examples of the imidization catalyst include a base catalyst or an acid catalyst.

Examples of the base catalyst include pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine (TEA), tripropylamine, Organic base catalysts such as tributylamine, triethylenediamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline, potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium hydrogen carbonate, sodium hydrogen carbonate, etc. of inorganic base catalysts.

Examples of the acid catalyst include crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methylbenzoic acid, oxybenzoic acid, terephthalic acid, benzenesulfonic acid, paratoluenesulfonic acid, and naphthalenesulfonic acid. The above imidization catalysts may be used alone or in combination of two or more.

Among the above, from the viewpoint of handling properties, it is preferable to use a base catalyst, it is more preferable to use an organic base catalyst, and it is still more preferable to use triethylamine.

The temperature of the imidation reaction is preferably 120 to 250°C, more preferably 160 to 200°C from the viewpoint of suppression of reaction rate and gelation. Further, the reaction time is preferably 0.5 to 10 hours after the start of outflow of the product water.

[Polyimide Varnish]

The polyimide varnish of the present invention is obtained by dissolving the polyimide resin of the present invention in an organic solvent. That is, the polyimide varnish of the present invention contains the polyimide resin of the present invention and an organic solvent, and the polyimide resin is dissolved in the organic solvent.

The organic solvent is not particularly limited as long as it dissolves the polyimide resin, but it is preferable to use the above-mentioned compounds alone or in a mixture of two or more as the reaction solvent used for the production of the polyimide resin.

The polyimide varnish of the present invention may be a polyimide solution itself in which the polyimide resin obtained by polymerization is dissolved in a reaction solvent, or may be diluted by adding a solvent to the polyimide solution.

Since the polyimide resin of this invention has solvent solubility, it can be set as the high-concentration varnish which is stable at room temperature. It is preferable that 5-40 mass % of polyimide resins of this invention are included, and, as for the polyimide varnish of this invention, it is more preferable that 10-30 mass % is included. 1-200 Pa.s is preferable and, as for the viscosity of a polyimide varnish, 1-100 Pa.s is more preferable. The viscosity of the polyimide varnish is a value measured at 25°C using an E-type viscometer.

In addition, the polyimide varnish of the present invention contains inorganic fillers, adhesion promoters, release agents, flame retardants, UV stabilizers, surfactants, leveling agents, defoamers, optical brighteners, crosslinking agents, It may contain various additives, such as a polymerization initiator and a photosensitizer.

The manufacturing method of the polyimide varnish of this invention is not specifically limited, A well-known method is applicable.

[Polyimide Film]

The polyimide film of this invention contains the polyimide resin of this invention. Accordingly, the polyimide film of the present invention is excellent in optical isotropy, flexibility, and chemical resistance. The suitable physical-property value which the polyimide film of this invention has is as above-mentioned.

There is no restriction|limiting in particular in the manufacturing method of the polyimide film of this invention, A well-known method can be used. For example, after the polyimide varnish of the present invention is coated on a smooth support such as a glass plate, a metal plate, or a plastic, or molded into a film, an organic solvent such as a reaction solvent or a diluent solvent contained in the varnish is heated. and a method of removing it by

As a coating method, well-known coating methods, such as spin coating, slit coating, and blade coating, are mentioned. Among these, a slit coat is preferable from a viewpoint of the point which chemical-resistance improves by controlling an intermolecular orientation, and workability|operativity.

As a method of removing the organic solvent contained in the varnish by heating, after evaporating the organic solvent at a temperature of 150° C. or less to make it tack-free, the temperature above the boiling point of the used organic solvent (not particularly limited, but preferably 200 It is preferred to dry at ~500°C). In addition, it is preferable to dry under an air atmosphere or a nitrogen atmosphere. The pressure of the dry atmosphere may be any of reduced pressure, normal pressure, and pressurization.

The method of peeling the polyimide film formed on the support from the support is not particularly limited, but a laser lift-off method, a method using a sacrificial layer for peeling (a method of applying a release agent to the surface of the support in advance), a release agent The method of adding is mentioned.

Moreover, the polyimide film of this invention can also be manufactured using the polyamic-acid varnish in which polyamic acid is melt|dissolved in the organic solvent.

The polyamic acid contained in the said polyamic acid varnish is a precursor of the polyimide resin of this invention, The tetracarboxylic-acid component containing the compound which gives the above-mentioned structural unit (A-1), and the above-mentioned structural unit It is a product of the heavy addition reaction of the compound which gives (B-1), and the diamine component containing the compound which gives a structural unit (B-2). By imidating this polyamic acid (ring closure by dehydration), the polyimide resin of the present invention as a final product is obtained.

As the organic solvent contained in the polyamic acid varnish, the organic solvent contained in the polyimide varnish of the present invention may be used.

In the present invention, the polyamic acid varnish may be a polyamic acid solution itself obtained by polyaddition reaction of a tetracarboxylic acid component and a diamine component in a reaction solvent, or diluted by adding a solvent to the polyamic acid solution it may have been

There is no restriction|limiting in particular in the method of manufacturing a polyimide film using a polyamic-acid varnish, A well-known method can be used. For example, a polyamic acid varnish is applied on a smooth support such as a glass plate, a metal plate, or a plastic, or is molded into a film, and an organic solvent such as a reaction solvent or a diluent solvent contained in the varnish is removed by heating. to obtain a polyamic acid film, and imidizing the polyamic acid in the polyamic acid film by heating, whereby a polyimide film can be produced.

As a heating temperature at the time of drying a polyamic-acid varnish and obtaining a polyamic-acid film, Preferably it is 50-120 degreeC. As a heating temperature at the time of imidating polyamic acid by heating, Preferably it is 200-400 degreeC.

On the other hand, the method of imidization is not limited to thermal imidization, and chemical imidation can also be applied.

The thickness of the polyimide film of the present invention can be appropriately selected depending on the use, etc., but is preferably in the range of 1 to 250 μm, more preferably 5 to 100 μm, still more preferably 8 to 80 μm, and still more preferably 10 to 80 μm. to be. Practical use as a self-supporting film becomes possible according to the thickness of 1-250 micrometers.

The thickness of the polyimide film can be easily controlled by adjusting the solid content concentration and viscosity of the polyimide varnish.

The polyimide film of this invention is used suitably as a film for various members, such as a color filter, a flexible display, a semiconductor component, and an optical member. The polyimide film of this invention is used especially suitably as a board|substrate of image display apparatuses, such as a liquid crystal display and an OLED display.

Example

Hereinafter, the present invention will be specifically described by way of Examples. However, the present invention is not limited by these Examples at all.

<Film properties and evaluation>

Each physical property of the film obtained by the Example and the comparative example was measured by the method shown below.

(1) Film thickness

The film thickness was measured using a micrometer manufactured by Mitsutoyo Corporation.

(2) Tensile strength, tensile modulus of elasticity, and tensile elongation at break (tensile elongation at break is evaluation of flexibility)

Tensile strength, tensile modulus of elasticity, and tensile elongation at break were measured in accordance with JIS K7127:1999, using a tensile tester "Strograph VG-1E" manufactured by Toyo Seiki Co., Ltd. The distance between chucks was 50 mm, the specimen size was 10 mm × 70 mm, and the test speed was 20 mm/min.

(3) Glass transition temperature (Tg)

Using the thermomechanical analysis device "TMA/SS6100" manufactured by Hitachi High-Tech Sciences, Ltd., the temperature sufficient to remove the residual stress under the conditions of a sample size of 2 mm × 20 mm in a tensile mode, a load of 0.1 N, and a temperature increase rate of 10 ° C/min. The temperature was raised to , to remove the residual stress, and then cooled to room temperature. Thereafter, the elongation of the specimen was measured under the same conditions as in the treatment for removing the residual stress, and the point where the inflection point of the elongation was observed was determined as the glass transition temperature.

(4) total light transmittance, and yellow index (YI)

The total light transmittance and YI were measured using the color and turbidity simultaneous measuring instrument "COH7700" manufactured by Nippon Denshoku Industries Co., Ltd. in conformity with JIS K7136.

(5) Haze

The measurement was carried out in accordance with JIS K7361-1, using a color and turbidity simultaneous measuring instrument "COH7700" manufactured by Nippon Densoku Industries Co., Ltd.

(6) Thickness retardation (Rth) (evaluation of optical isotropy)

The thickness retardation (Rth) was measured using an ellipsometer "M-220" manufactured by Nippon Spectroscopy Corporation. The value of the thickness phase difference in the measurement wavelength of 590 nm was measured. On the other hand, Rth is expressed by the following formula when the maximum in-plane refractive index of the polyimide film is nx, the minimum is ny, the refractive index in the thickness direction is nz, and the thickness of the film is d. Rth which converted the thickness of a film into 10 micrometers was also computed.

Rth=[{(nx+ny)/2}-nz]×d

(7) Solvent resistance (evaluation of chemical resistance)

The polyimide film formed into a film on the glass plate was immersed in the solvent at room temperature, and it was confirmed whether there was no change in the film surface. In addition, as a solvent, propylene glycol monomethyl ether acetate (PGMEA) was used.

The evaluation criteria of solvent resistance were as follows.

(circle): There was no change in the film surface.

(triangle|delta): A crack arose slightly on the film surface.

x: A crack arose on the film surface, or the film surface melt|dissolved.

<Abbreviation of ingredients, etc.>

The tetracarboxylic acid component and diamine component used in Examples and Comparative Examples, and their abbreviations are as follows.

(Tetracarboxylic acid component)

ODPA: 4,4'-oxydiphthalic anhydride (manufactured by Manak Corporation; compound represented by formula (a-1))

HPMDA: 1,2,4,5-cyclohexanetetracarboxylic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd.; compound represented by formula (a-2-1))

CpODA: norbornane-2-spiro-α-cyclopentanone-α′-spiro-2”-norbonane-5,5”,6,6”-tetracarboxylic dianhydride (manufactured by JXTG Energy Co., Ltd.; formula (a) A compound represented by -2-2))

6FDA: 4,4'-(hexafluoroisopropylidene)diphthalic anhydride

(Diamine component)

6FODA: 4,4'-diamino-2,2'-bistrifluoromethyldiphenyl ether (made by ChinaTech Chemical (Tianjin) Co., Ltd.; compound represented by formula (b-1))

1,3-BAC: 1,3-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.; compound represented by formula (b-2a))

1,4-BAC: 1,4-bis(aminomethyl)cyclohexane (compound represented by formula (b-2b); trans ratio 40%)

1,4-BACT: 1,4-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd.; compound represented by formula (b-2b); trans ratio 85%)

X-22-9409: (manufactured by Shin-Etsu Chemical Industry Co., Ltd.; compound represented by formula (b-3-1))

4,4'-DDS: 4,4'-diaminodiphenylsulfone (manufactured by Seika Corporation; compound represented by formula (b-3-2))

3,3'-DDS: 3,3'-diaminodiphenylsulfone (manufactured by Seika Co., Ltd.)

TFMB: 2,2'-bis(trifluoromethyl)benzidine (manufactured by Seika Corporation)

<Production of polyimide resin, varnish and polyimide film>

Example 1

16.812 g (0.0500 mol) of 6FODA, 1,4-BACT in a 300 mL 5-neck round-bottom flask equipped with stainless steel semi-lunar stirring blades, nitrogen introduction tube, Dean-Stark with cooling tube, thermometer, and glass end cap. 7.113 g (0.0500 mol) and 65.935 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.) were added, and stirred at a system temperature of 70° C., nitrogen atmosphere, and rotation speed 200 rpm to obtain a solution.

To this solution, 31.021 g (0.100 mol) of ODPA and 16.484 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.) were added at once, followed by 0.506 triethylamine (manufactured by Kanto Chemical Co., Ltd.) as an imidization catalyst. g, and heated with a mantle heater to raise the internal temperature of the reaction system to 190°C over about 20 minutes. The components being distilled were collected, and while the number of rotations was adjusted according to the increase in viscosity, the temperature inside the reaction system was maintained at 190° C. and refluxed for about 5 hours.

Thereafter, 208.517 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.) was added so that the solid content concentration was 15% by mass, and the reaction system internal temperature was cooled to 100° C. got varnish.

Next, on a glass plate, the obtained polyimide varnish was applied by spin coating, held on a hot plate at 80° C. for 20 minutes, and then heated at 300° C. in a hot air dryer under a nitrogen atmosphere for 30 minutes (temperature increase rate of 5° C.) /min), the solvent was evaporated to obtain a film.

Example 2

A polyimide varnish was prepared in the same manner as in Example 1 except that the amount of ODPA was changed from 31.021 g (0.100 mol) to 24.817 g (0.080 mol) and CpODA was added 7.688 g (0.020 mol), A polyimide varnish having a solid content concentration of 15% by mass was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 3

The amount of 6FODA was changed from 16.812 g (0.0500 mol) to 16.429 g (0.04886 mol), and the amount of 1,4-BACT was changed from 7.113 g (0.0500 mol) to 6.950 g (0.04886 mol), X-22- Except having added 2.941 g (0.00228 mol) of 9409, the polyimide varnish was produced by the method similar to Example 2, and the polyimide varnish of 15 mass % of solid content concentration was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 4

The amount of 6FODA was changed from 16.812 g (0.0500 mol) to 16.012 g (0.04762 mol), and the amount of 1,4-BACT was changed from 7.113 g (0.0500 mol) to 6.774 g (0.04762 mol), X-22- Except having added 6.140 g (0.00476 mol) of 9409, the polyimide varnish was produced by the method similar to Example 2, and the polyimide varnish of 15 mass % of solid content concentration was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 5

The amount of ODPA was changed from 31.021 g (0.100 mol) to 15.511 g (0.050 mol), CpODA was added 19.219 g (0.050 mol), and the amount of 6FODA was changed from 16.812 g (0.0500 mol) to 15.980 g (0.04753 mol). Example 1, except that the amount of 1,4-BACT was changed from 7.113 g (0.0500 mol) to 6.760 g (0.04753 mol), and 6.386 g (0.00495 mol) of X-22-9409 was added. The polyimide varnish was produced by the same method, and the polyimide varnish of 15 mass % of solid content concentration was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 6

A polyimide varnish was prepared in the same manner as in Example 1, except that the amount of ODPA was added from 31.021 g (0.100 mol) to 15.511 g (0.050 mol) and HPMDA was added to 11.209 g (0.050 mol), and the solid content was 15 A mass % polyimide varnish was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 7

A polyimide varnish was prepared in the same manner as in Example 2 except that 7.688 g (0.020 mol) of CpODA was changed to 4.483 g (0.020 mol) of HPMDA, and a polyimide varnish having a solid content concentration of 15% by mass was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 8

Implemented except that the amount of 6FODA was changed from 16.812 g (0.0500 mol) to 6.725 g (0.020 mol) and the amount of 1,4-BACT was changed from 7.113 g (0.0500 mol) to 11.380 g (0.080 mol) The polyimide varnish was produced by the method similar to Example 6, and the polyimide varnish of 15 mass % of solid content concentration was obtained.

Then, on a glass plate, the obtained polyimide varnish is applied by spin coating, held on a hot plate at 80° C. for 20 minutes, and then heated in an air atmosphere at 240° C. in a hot air dryer for 60 minutes, and the solvent is evaporated. , a film was obtained.

Example 9

A polyimide varnish was produced in the same manner as in Example 1 except that 7.113 g (0.0500 mol) of 1,4-BACT was changed to 7.113 g (0.0500 mol) of 1,3-BAC, and a solid content concentration of 15% by mass. of polyimide varnish was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Example 10

6 Implemented except that the amount of FODA was changed from 16.812 g (0.0500 mol) to 13.450 g (0.0400 mol) and the amount of 1,4-BACT was changed from 7.113 g (0.0500 mol) to 8.535 g (0.0600 mol) The polyimide varnish was produced by the method similar to Example 6, and the polyimide varnish of 15 mass % of solid content concentration was obtained.

Next, on a glass plate, the obtained polyimide varnish is applied by spin coating, held on a hot plate at 80° C. for 20 minutes, and then heated at 260° C. in an air atmosphere in a hot air dryer for 30 minutes, and the solvent is evaporated. , a film was obtained.

Example 11

A polyimide varnish was prepared in the same manner as in Example 6, except that 7.113 g (0.0500 mol) of 1,4-BACT was changed to 7.113 g (0.0500 mol) of 1,4-BAC, and a solid content concentration of 15% by mass. of polyimide varnish was obtained.

The film was obtained by the method similar to Example 10 using the obtained polyimide varnish.

Example 12

Polyimide in the same manner as in Example 6 except that the amount of 6FODA was changed from 16.812 g (0.0500 mol) to 10.087 g (0.0300 mol) and 4.966 g (0.0200 mol) of 4,4'-DDS was added. The varnish was produced and the polyimide varnish with a solid content concentration of 15 mass % was obtained.

The film was obtained by the method similar to Example 10 using the obtained polyimide varnish.

Comparative Example 1

A polyimide varnish was produced in the same manner as in Example 1, except that 16.812 g (0.0500 mol) of 6FODA was changed to 16.012 g (0.0500 mol) of TFMB, and a polyimide varnish having a solid content concentration of 15% by mass was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Comparative Example 2

Example except that the amount of 6FODA was changed from 16.812 g (0.0500 mol) to 33.624 g (0.100 mol) and the amount of 1,4-BACT was changed from 7.113 g (0.0500 mol) to 0 g (0 mol) The polyimide varnish was produced by the method similar to 1, and the polyimide varnish of 15 mass % of solid content concentration was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Comparative Example 3

A polyimide varnish was prepared in the same manner as in Example 9 except that 16.812 g (0.0500 mol) of 6FODA was changed to 12.415 g (0.0500 mol) of 3,3'-DDS, and a polyimide having a solid content concentration of 15% by mass. got varnish.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Comparative Example 4

A polyimide varnish was prepared in the same manner as in Example 1 except that ODPA 31.021 g (0.100 mol) was changed to 6FDA 44.424 g (0.100 mol), and a polyimide varnish having a solid content concentration of 15% by mass was obtained.

The film was obtained by the method similar to Example 1 using the obtained polyimide varnish.

Comparative Example 5

31.021 g (0.100 mol) of ODPA was changed to 22.417 g (0.100 mol) of HPMDA, the amount of 6FODA was changed from 16.812 g (0.0500 mol) to 33.624 g (0.100 mol), and the amount of 1,4-BACT was changed to 7.113 g Except having changed from (0.0500 mol) to 0 g (0 mol), the polyimide varnish was produced by the method similar to Example 1, and the polyimide varnish of 15 mass % of solid content concentration was obtained.

The film was obtained by the method similar to Example 10 using the obtained polyimide varnish.

The above-described physical properties were measured and evaluated for the polyimide films obtained in Examples and Comparative Examples. A result is shown in Table 1.

[Table 1]

As shown in Table 1, it turns out that the polyimide film of an Example has favorable optical isotropy, and also excellent also flexibility and chemical-resistance.

Claims (8)

A polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine,
Structural unit A includes a structural unit (A-1) derived from a compound represented by the following formula (a-1),
The structural unit B includes a structural unit (B-1) derived from a compound represented by the following formula (b-1) and a structural unit (B-2) derived from a compound represented by the following formula (b-2) polyimide resin.
[Formula 1]

According to claim 1,
The polyimide resin wherein the proportion of the structural unit (B-1) in the structural unit B is 5-80 mol%, and the proportion of the structural unit (B-2) in the structural unit B is 20-95 mol%. 3. The method of claim 1 or 2,
The polyimide resin, wherein the molar ratio [(B-1)/(B-2)] of the structural unit (B-1) to the structural unit (B-2) in the structural unit B is 5/95 to 80/20; . 4. The method according to any one of claims 1 to 3,
Structural unit A is a structural unit derived from a compound represented by the following formula (a-2-1) (A-2-1), and a structural unit derived from a compound represented by the following formula (a-2-2) The polyimide resin further comprising at least one selected from the group consisting of (A-2-2).
[Formula 2]

5. The method according to any one of claims 1 to 4,
The structural unit B is a structural unit derived from a compound represented by the following formula (b-3-1) (B-3-1), and a structural unit derived from a compound represented by the following formula (b-3-2) (B-3-2) A polyimide resin further comprising at least one selected from the group consisting of.
[Formula 3]

(In formula (b-3-1), Z ¹ and Z ² each independently represent a divalent aliphatic group or a divalent aromatic group which may contain an oxygen atom, and R ¹ and R ² are each independently 1 represents a valent aromatic group or a monovalent aliphatic group, R ³ and R ⁴ each independently represent a monovalent aliphatic group, R ⁵ and R ⁶ each independently represent a monovalent aliphatic group or a monovalent aromatic group, m and n are Each independently represents an integer of 1 or more, and the sum of m and n represents an integer of 2 to 1000. However, at least one of R ¹ and R ² represents a monovalent aromatic group.) 6. The method of claim 5,
The polyimide resin wherein R ¹ and R ² in the formula (b-3-1) are phenyl groups. A polyimide varnish formed by dissolving the polyimide resin according to any one of claims 1 to 6 in an organic solvent. The polyimide film containing the polyimide resin in any one of Claims 1-6.