KR20210047858A - Polyimide resin, polyimide varnish and polyimide film - Google Patents

Abstract

(식 중, X¹~X⁴는 각각 독립적으로, 단결합, 탄소수 1~5의 알킬렌기, 탄소수 2~5의 알킬리덴기, -S-, -SO-, -SO₂-, -O- 또는 -CO-를 나타낸다.)The present invention is a polyimide resin having a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine, wherein the structural unit A is a structural unit derived from a compound represented by formula (a-1) (A-1) and at least one constitutional unit selected from the group consisting of constitutional units (A-2) derived from compounds represented by formula (a-2), and constitutional unit B is represented by the general formula ( Containing at least one structural unit (B-1) selected from the group consisting of a structural unit derived from a compound represented by b1-1), and a structural unit derived from a compound represented by general formula (b2-1) , It relates to a polyimide resin, and provides a polyimide resin, a polyimide varnish, and a polyimide film capable of forming a film having excellent colorless transparency and further low retardation.

(In the formula, X ¹ to X ⁴ are each independently a single bond, an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, -S-, -SO-, -SO ₂ -, -O- Or -CO-.)

Description

Polyimide resin, polyimide varnish and polyimide film

The present invention relates to a polyimide resin, a polyimide varnish, and a polyimide film.

Polyimide resins have been studied for various uses in fields such as electric and electronic parts. For example, it is desired to replace glass substrates used in image display devices such as liquid crystal displays and OLED displays with plastic substrates for the purpose of reducing device weight or flexibility, and polyimide films suitable as corresponding plastic substrates. Research is ongoing. The polyimide film for this purpose is required to have colorless transparency.

Further, as required characteristics of the polyimide film, it is required that the retardation due to birefringence is small and retardation is low.

In Patent Document 1, as a polyimide resin providing a film with reduced birefringence, a diamine (for example, metaphenylenediamine) in which at least one of the amino groups of the diamine is bonded to the meta position with respect to the main chain is used. The resulting polyimide resin is disclosed.

In Patent Document 2, as a polyimide resin that imparts a film excellent in heat resistance, transmittance, low linear expansion coefficient and low retardation, a tetracarboxylic acid residue and a diamine residue having a specific structure, a tetracarboxylic acid residue having a bent portion, and/or A polyimide resin containing a diamine residue is disclosed, and specifically, 3,3',4,4'-biphenyltetracarboxylic dianhydride and 3,3',4,4'-bicyclohexanetetracarboxylic acid are Polyimide resins obtained using anhydride, pyromellitic anhydride, 2,2'-bis(trifluoromethyl)benzidine, and 4,4'-diaminodiphenylsulfone are disclosed.

Japanese Patent Laid-Open No. H8-134211 International Publication No. 2015/125895

As described above, although various properties are required for the polyimide film, it is not easy to satisfy these properties at the same time.

The present invention has been made in view of such a situation, and the subject of the present invention is a polyimide resin capable of forming a film having excellent colorless transparency and further low retardation, and a polyimide varnish and polyimide resin including the polyimide resin. It is in providing mid-film.

The inventors of the present invention have found that a polyimide resin containing a combination of a specific structural unit can solve the above problem, and have come to complete the invention.

That is, the present invention relates to the following [1] to [9].

[One]

A polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine,

Structural unit A is a structural unit (A-1) derived from a compound represented by the following formula (a-1), and a structural unit (A-2) derived from a compound represented by the following formula (a-2). It contains at least one constituent unit selected from the group consisting of,

Structural unit B is at least one selected from the group consisting of a structural unit derived from a compound represented by the following general formula (b1-1), and a structural unit derived from a compound represented by the following general formula (b2-1) Polyimide resin containing a structural unit (B-1).

[Formula 1]

(In the formula, X ¹ to X ⁴ are each independently a single bond, an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, -S-, -SO-, -SO ₂ -, -O- Or -CO-.)

[2]

The polyimide resin according to the above [1], wherein the proportion of the structural unit (B-1) in the structural unit B is 5 to 100 mol%.

[3]

The polyimide according to [1] or [2], wherein the structural unit A contains the structural unit (A-1), and the proportion of the structural unit (A-1) in the structural unit A is 45 to 100 mol%. Suzy.

[4]

The structural unit (B-1) is a structural unit derived from a compound represented by the following formula (b1-1-1), a structural unit derived from a compound represented by the following formula (b1-1-2), and the following formula: The polyimide resin according to any one of [1] to [3], comprising at least one structural unit selected from the group consisting of structural units derived from the compound represented by (b1-1-3).

[Formula 2]

[5]

Constituent unit B is a structural unit derived from a compound represented by the following formula (b-2) (B-2), and a structural unit derived from a compound represented by the following formula (b-3) (B-3) , And at least one structural unit selected from the group consisting of a structural unit (B-4) derived from a compound represented by the following formula (b-4). The described polyimide resin.

[Formula 3]

[6]

The polyie according to [5], wherein the proportion of the total of the structural unit (B-2), the structural unit (B-3), and the structural unit (B-4) in the structural unit B is 5 to 95 mol%. Suzy Mid.

[7]

The polyimide resin according to any one of the above [1] to [6], wherein the structural unit A further contains a structural unit (A-3) derived from a compound represented by the following formula (a-3).

[Formula 4]

[8]

A polyimide varnish obtained by dissolving the polyimide resin according to any one of the above [1] to [7] in an organic solvent.

[9]

A polyimide film containing the polyimide resin according to any one of the above [1] to [7].

According to the present invention, a polyimide resin capable of forming a film having excellent colorless transparency and further low retardation, and a polyimide varnish and a polyimide film including the polyimide resin can be provided.

[Polyimide resin]

The polyimide resin of the present invention has a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine, and the structural unit A is derived from a compound represented by the following formula (a-1). And at least one structural unit selected from the group consisting of a unit (A-1) and a structural unit (A-2) derived from a compound represented by the following formula (a-2),

Structural unit B is at least one selected from the group consisting of a structural unit derived from a compound represented by the following general formula (b1-1), and a structural unit derived from a compound represented by the following general formula (b2-1) It includes a structural unit (B-1).

[Formula 5]

(In the formula, X ¹ to X ⁴ are each independently a single bond, an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, -S-, -SO-, -SO ₂ -, -O- Or -CO-.)

<Constituent Unit A>

Structural unit A is a structural unit derived from a tetracarboxylic dianhydride occupied in the polyimide resin, and the structural unit A is a structural unit (A-1) derived from a compound represented by the following formula (a-1), and It contains at least one structural unit selected from the group consisting of structural units (A-2) derived from compounds represented by the following formula (a-2).

[Formula 6]

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

When the structural unit A contains the structural unit (A-1), the colorless transparency, heat resistance, and thermal stability of the film are improved.

The compound represented by formula (a-2) is 4,4'-(hexafluoroisopropylidene)diphthalic anhydride.

When the structural unit A contains the structural unit (A-2), the transparency of the film is improved, and the solubility of the polyimide in the organic solvent is improved.

Constituent unit A may include both a constituent unit (A-1) and a constituent unit (A-2), preferably among the constituent units (A-1) or (A-2) Either one is included, and more preferably the structural unit (A-1) is included.

When the constituent unit A includes the constituent unit (A-1) and the constituent unit (A-2), the ratio of the sum of the constituent units (A-1) and (A-2) in the constituent unit A is preferably Preferably it is 50 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, particularly preferably 99 mol% or more. The upper limit of the ratio of the total of the structural units (A-1) and (A-2) is not particularly limited, that is, 100 mol%.

When the structural unit A contains the structural unit (A-1), the proportion of the structural unit (A-1) in the structural unit A is preferably 45 mol% or more, more preferably 70 mol% or more, It is more preferably 90 mol% or more, particularly preferably 99 mol% or more. The upper limit of the ratio is not particularly limited, that is, 100 mol%. Similarly, the proportion of the structural unit (A-1) in the structural unit A is preferably 45 to 100 mol%, more preferably 70 to 100 mol%, still more preferably 90 to 100 mol%, particularly preferably It is 99 to 100 mol%.

When the structural unit A contains the structural unit (A-2), the proportion of the structural unit (A-2) in the structural unit A is preferably 45 mol% or more, more preferably 70 mol% or more, It is more preferably 90 mol% or more, particularly preferably 99 mol% or more. The upper limit of the ratio is not particularly limited, that is, 100 mol%. Similarly, the proportion of the structural unit (A-2) in the structural unit A is preferably 45 to 100 mol%, more preferably 70 to 100 mol%, further preferably 90 to 100 mol%, particularly preferably It is 99 to 100 mol%.

The structural unit A may further contain a structural unit (A-3) derived from a compound represented by the following formula (a-3).

[Formula 7]

The compound represented by formula (a-3) is nobonan-2-spiro-α-cyclopentanone-α'-spiro-2''-novonane-5,5'',6,6''-tetra It is a carboxylic acid dianhydride. When the structural unit A contains the structural unit (A-3), the colorless transparency of the film is improved.

When the constituent unit A contains the constituent unit (A-3), the proportion of the constituent unit (A-13) in the constituent unit A is preferably 55 mol% or less, more preferably 30 mol% or less. .

When the structural unit A includes the structural unit (A-3), the structural unit A preferably includes the structural unit (A-1) and the structural unit (A-3), and more preferably, the structural unit ( It consists of A-1) and a structural unit (A-3).

Structural unit A may contain structural units other than structural units (A-1) to (A-3) within a range that does not impair the effects of the present invention. The tetracarboxylic acid dianhydride giving such a structural unit is not particularly limited, but pyromellitic dianhydride, 3,3',4,4'-diphenylsulfone tetracarboxylic dianhydride, 3,3',4 ,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 4,4'-oxydiphthalic anhydride, 3,3',4,4'- Aromatic tetracarboxylic acids such as biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, and 2,2',3,3'-biphenyltetracarboxylic dianhydride, etc. anhydride; 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,4,5-cyclopentanetetracarboxylic dianhydride, bicyclo[2.2.2]octa-7-ene-2,3,5 Alicyclic tetracarboxylic dianhydrides such as ,6-tetracarboxylic dianhydride and dicyclohexyltetracarboxylic dianhydride; And aliphatic tetracarboxylic dianhydrides, such as 1,2,3,4-butane tetracarboxylic dianhydride, are mentioned.

On the other hand, in the present specification, the aromatic tetracarboxylic dianhydride refers to a tetracarboxylic dianhydride containing at least one aromatic ring, and the alicyclic tetracarboxylic dianhydride includes at least one alicyclic ring, and the aromatic ring It means a tetracarboxylic acid dianhydride which does not contain, and the aliphatic tetracarboxylic acid dianhydride means a tetracarboxylic acid dianhydride which does not contain neither an aromatic ring nor an alicyclic ring.

Constituent units other than the constituent units (A-1) to (A-3) optionally included in the constituent unit A may be one type or two or more types.

It is preferable that the structural unit A does not contain structural units other than the structural units (A-1) to (A-3).

<Constituent Unit B>

Structural unit B is a structural unit derived from a diamine occupied in the polyimide resin, and a structural unit derived from a compound represented by the following general formula (b1-1), and a compound represented by the following general formula (b2-1) It contains at least one structural unit (B-1) selected from the group consisting of derived structural units.

[Formula 8]

In formulas (b1-1) and (b2-1), X ¹ to X ⁴ are each independently a single bond, a C 1 to C 5 alkylene group, a C 2 to C 5 alkylidene group, -S-, -SO -, -SO ₂ -, -O-, or -CO-.

When the structural unit B contains the structural unit (B-1), the colorless transparency of the film is improved, and the retardation value is lowered. The structural unit (B-1) may be one type or two or more types.

The compound represented by the general formula (b1-1) is, X ^1, and is connected to three benzene ring via the X ^2, X ¹ and X ² have the skeleton is bonded to the benzene ring of the 1,3 position in the center, formula the compound represented by (b2-1) is, X ³ and X ⁴ is connected to ring 3 via the benzene, and has a backbone combines the X ³ and X ⁴ on the benzene ring and second position of the center. By having such a skeletal structure in the structural unit B in the polyimide resin, it becomes possible to form a film excellent in low retardation.

^{X 1} to X ⁴ in the general formulas (b1-1) and (b2-1) are each independently, preferably an alkylidene group having 3 to 5 carbon atoms from the viewpoint of forming a film excellent in low retardation , -SO ₂ -, or -O-, more preferably an alkylidene group having 3 to 5 carbon atoms, or -O-, more preferably an isopropylidene group or -O-, and more More preferably, it represents an isopropylidene group.

^{Although X 1} and X ² in General Formula (b1-1) may each have different groups, it is preferable that they are the same group. Similarly, although X ³ and X ⁴ in formula (b2-1) may each have different groups, it is preferable that they are the same group.

The amino group in the general formulas (b1-1) and (b2-1) is bonded to the para-position or meta-position of the benzene ring with respect to any one of ^{X 1} to X ^{4 bonded to the benzene ring to which each amino group is bonded} It is desirable to do it.

The structural unit (B-1) preferably includes a structural unit derived from a compound represented by the general formula (b1-1), and a constitution derived from a compound represented by the following formula (b1-1-1) At least one constitution selected from the group consisting of a unit, a constituent unit derived from a compound represented by the following formula (b1-1-2), and a constituent unit derived from a compound represented by the following formula (b1-1-3) It is more preferable to include a unit.

[Formula 9]

The compound represented by formula (b1-1-1) is 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene,

The compound represented by formula (b1-1-2) is 1,3-bis(4-aminophenoxy)benzene,

The compound represented by formula (b1-1-3) is 1,3-bis(3-aminophenoxy)benzene.

Among the compounds represented by formulas (b1-1-1) to (b1-1-3), preferably, compounds represented by formula (b1-1-1), and formula (b1-1-2) It is at least one compound selected from the group consisting of the compounds represented, and more preferably is a compound represented by formula (b1-1-1).

The proportion of the constituent unit (B-1) in the constituent unit B is preferably 5 mol% or more, more preferably 15 mol% or more, still more preferably 45 mol% or more, particularly preferably 75 mol%. That's it. The upper limit of the proportion of the structural unit (B-1) is not particularly limited, that is, 100 mol%. Constituent unit B may consist of only constituent units (B-1).

The proportion of the structural unit (B-1) in the structural unit B is preferably 5 to 100 mol%, more preferably 15 to 100 mol%, still more preferably 45 to 100 mol%, particularly preferably It is 75-100 mol%.

When the structural unit (B-1) contains a structural unit derived from the compound represented by the formula (b1-1-1), it is represented by the formula (b1-1-1) in the structural unit (B-1). The proportion of the constituent units derived from the compound is preferably 50 to 100 mol%, more preferably 75 to 100 mol%, still more preferably 90 to 100 mol%, and particularly preferably 95 to 100 mol%. .

Constituent unit B may include constituent units other than the constituent unit (B-1). The structural unit is not particularly limited, but a structural unit derived from a compound represented by the following formula (b-2) (B-2), a structural unit derived from a compound represented by the following formula (b-3) ( It is preferable to include at least one structural unit selected from the group consisting of B-3) and a structural unit (B-4) derived from a compound represented by the following formula (b-4).

[Formula 10]

The compound represented by formula (b-2) is 2,2-bis[4-(4-aminophenoxy)phenyl]propane,

The compound represented by formula (b-3) is 4,4'-diaminodiphenyl ether,

The compound represented by formula (b-4) is 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene.

When the constituent unit B contains at least one constituent unit selected from the group consisting of constituent units (B-2) to (B-4), at least two of the constituent units (B-2) to (B-4) Although it may contain, it is preferable to include one of the structural units (B-2) to (B-4). That is, it is preferable that the structural unit B includes a structural unit (B-2), a structural unit (B-3), or a structural unit (B-4).

When structural unit B contains at least one structural unit selected from the group consisting of structural units (B-2) to (B-4), structural units (B-2) to (B-) in structural unit B The proportion occupied by the total of 4) is preferably 5 to 95 mol%, more preferably 7 to 85 mol%, still more preferably 10 to 55 mol%, and particularly preferably 12 to 25 mol%.

The structural unit B may include structural units other than the structural units (B-1) to (B-4). The diamine giving such a structural unit is not particularly limited, but 1,4-phenylenediamine, p-xylylenediamine, 3,5-diaminobenzoic acid, 1,5-diaminonaphthalene, 2,2'- Dimethylbiphenyl-4,4'-diamine, 2,2'-bis(trifluoromethyl)benzidine, 4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)hexafluoro Propane, 4,4'-diaminodiphenylsulfone, 4,4'-diaminobenzanilide, 3,4'-diaminodiphenylether, 1-(4-aminophenyl)-2,3-dihydro- 1,3,3-trimethyl-1H-inden-5-amine, N,N'-bis(4-aminophenyl)terephthalamide, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2 -Bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane and 9,9-bis(4-aminophenyl) ) Aromatic diamines such as fluorene and 1,4-bis(4-aminophenoxy)benzene; Alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane and 1,4-bis(aminomethyl)cyclohexane; And aliphatic diamines, such as ethylenediamine and hexamethylenediamine, are mentioned.

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

Constituent units other than the constituent units (B-1) to (B-4) optionally included in the constituent unit B may be one type or two or more types.

It is preferable that the structural unit B does not contain structural units other than the structural units (B-1) to (B-4).

The number average molecular weight of the polyimide resin of the present invention is preferably 5,000 to 100,000 from the viewpoint of the mechanical strength of the obtained polyimide film. On the other hand, the number average molecular weight of the polyimide resin can be obtained, for example, from a value in terms of standard polymethyl methacrylate (PMMA) measured by gel filtration chromatography.

The polyimide resin of the present invention may contain a structure other than a polyimide chain (a structure formed by imide bonding of the structural unit A and the structural unit B). Examples of structures other than the polyimide chain that may be contained in the polyimide resin include structures including an amide bond.

It is preferable that the polyimide resin of the present invention contains a polyimide chain (a structure formed by imide bonding of the structural unit A and the structural unit B) as a main structure. Therefore, the proportion of the polyimide chain in the polyimide resin of the present invention is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, particularly preferably It is 99% by mass or more.

By using the polyimide resin of the present invention, a film having excellent colorless transparency and further low retardation can be formed, and suitable physical property values of the film are as follows.

The total light transmittance is preferably 85% or more, more preferably 87% or more, still more preferably 88% or more, even more preferably 89% or more, when a film having a thickness of 30 μm is used.

When the haze is a film having a thickness of 30 μm, it is preferably 2.0% or less, more preferably 1.5% or less, and still more preferably 1.0% or less.

When the yellow index (YI) is a film having a thickness of 30 μm, it is preferably 4.0 or less, more preferably 3.5 or less, still more preferably 3.0 or less, and even more preferably 2.0 or less.

In the present invention, a polyimide film having a thickness phase difference (Rth) of preferably 90 nm or less, more preferably 70 nm or less, still more preferably 50 nm or less, and even more preferably 30 nm or less can be used. On the other hand, in the present specification, "low retardation" means that the thickness phase difference Rth is low, and preferably the thickness phase difference Rth is within the above range.

On the other hand, the above-described physical property values in the present invention can be specifically measured by the method described in Examples.

The film which can be formed by using the polyimide resin of the present invention also has good heat resistance and mechanical properties, and has the following favorable physical property values.

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.

The tensile modulus is preferably 2.5 GPa or more, more preferably 3.0 GPa or more, and still more preferably 3.5 GPa or more.

The tensile strength is preferably 70 MPa or more, more preferably 90 MPa or more, and even more preferably 100 MPa or more.

Tensile modulus and tensile strength are values measured according to JIS K7127:1999.

[Method of manufacturing polyimide resin]

The polyimide resin of the present invention is a tetra containing at least one selected from the group consisting of a compound that imparts the structural unit (A-1) described above and a compound that imparts the structural unit (A-2) described above. It can be produced by reacting a carboxylic acid component with a diamine component containing a compound that imparts the structural unit (B-1) described above.

Examples of the compound to impart the structural unit (A-1) include, but are not limited to, the compound represented by the formula (a-1), and may be a derivative thereof within the range to which the same structural unit is imparted. Examples of the derivative include tetracarboxylic acid corresponding to the tetracarboxylic acid dianhydride represented by formula (a-1) and the alkyl ester of the tetracarboxylic acid. As the compound giving the structural unit (A-1), a compound represented by formula (a-1) (that is, a dianhydride) is preferable.

Similarly, examples of the compound that imparts the structural unit (A-2) include, but are not limited to, the compound represented by the formula (a-2), and may be a derivative thereof within the range of imparting the same structural unit. . Examples of the derivative include tetracarboxylic acid corresponding to the tetracarboxylic dianhydride represented by formula (a-2) and the alkyl ester of the tetracarboxylic acid. As the compound giving the structural unit (A-2), a compound represented by formula (a-2) (that is, a dianhydride) is preferable.

The tetracarboxylic acid component, in total, preferably contains 50 mol% or more, and more preferably 70 mol%, in total, of the compound giving the constituent unit (A-1) and the compound giving the constituent unit (A-2). It contains more than, More preferably, it contains 90 mol% or more, Especially preferably, it contains 99 mol% or more. The upper limit of the total content of the compound giving the structural unit (A-1) and the compound giving the structural unit (A-2) is not particularly limited, that is, 100 mol%. The tetracarboxylic acid component may consist of only the compound which gives the structural unit (A-1) and the compound which gives the structural unit (A-2).

When the tetracarboxylic acid component contains a compound that provides a structural unit (A-1) or a compound that provides a structural unit (A-2), a compound that provides the structural unit (A-1), or a structural unit The compound to which (A-2) is imparted is preferably contained in an amount of 45 mol% or more, more preferably 70 mol% or more, and still more preferably 90 mol% or more. The upper limit of the content of the compound giving the structural unit (A-1) or the compound giving the structural unit (A-2) is not limited, that is, 100 mol%. The tetracarboxylic acid component may consist of only the compound which gives the constituent unit (A-1) or the compound which gives the constituent unit (A-2), and is preferably made of only the compound which gives the constituent unit (A-1) .

The tetracarboxylic acid component may contain a compound that imparts the above-described structural unit (A-3) within a range that does not impair the physical properties of low retardation.

Examples of the compound to impart the structural unit (A-3) include, but are not limited to, the compound represented by the formula (a-3), and may be a derivative thereof within the range to which the same structural unit is imparted. Examples of the derivative include tetracarboxylic acid corresponding to the tetracarboxylic acid dianhydride represented by formula (a-3) and the alkyl ester of the tetracarboxylic acid. As the compound giving the structural unit (A-3), a compound represented by formula (a-3) (that is, a dianhydride) is preferable.

When the tetracarboxylic acid component contains a compound that imparts the structural unit (A-3), the compound that imparts the structural unit (A-3) is preferably 55 mol% or less, more preferably 30 mol%. Included below. When the tetracarboxylic acid component contains the compound which gives the structural unit (A-3), it is preferable that it consists only of the compound which gives the structural unit (A-1) and the compound which gives the structural unit (A-3) .

The tetracarboxylic acid component may contain compounds other than the compound which gives the structural unit (A-1), the compound which gives the structural unit (A-2), and the compound which gives the structural unit (A-3), , As the compound, the above-described aromatic tetracarboxylic dianhydride, alicyclic tetracarboxylic dianhydride, and aliphatic tetracarboxylic dianhydride, and their derivatives (tetracarboxylic acid, alkyl ester of tetracarboxylic acid, etc.) are mentioned. I can.

The number of compounds other than the compound which imparts structural units (A-1) to (A-3) optionally contained in the tetracarboxylic acid component may be one or two or more.

Examples of the compound giving the structural unit (B-1) include compounds represented by the general formula (b1-1) and compounds represented by the general formula (b2-1), but are not limited thereto, and the same It may be a derivative thereof within the range of giving a structural unit. Examples of the derivatives include diisocyanates corresponding to the compounds represented by general formula (b1-1) and diisocyanates corresponding to diamines represented by general formula (b2-1). As the compound giving the structural unit (B-1), at least one compound selected from the group consisting of a compound represented by the general formula (b1-1) and a compound represented by the general formula (b2-1) (i.e. , Diamine) is preferred.

As the compound giving the structural unit (B-1), it is preferable to include the compound represented by the general formula (b1-1), and the compound represented by the formula (b1-1-1) or the formula (b1-1) It is more preferable to contain at least one compound selected from the group consisting of a compound represented by -2) and a compound represented by formula (b1-1-3), and represented by formula (b1-1-1) It is more preferable to include at least one compound selected from the group consisting of a compound and a compound represented by formula (b1-1-2), and particularly, to include a compound represented by formula (b1-1-1) desirable.

The diamine component contains a compound that imparts the constituent unit (B-1), preferably 5 mol% or more, more preferably 15 mol% or more, still more preferably 45 mol% or more, particularly Preferably it contains 75 mol% or more. The upper limit of the content of the compound that imparts the structural unit (B-1) is not particularly limited, that is, it is 100 mol%. The diamine component may consist of only a compound which imparts a structural unit (B-1).

When the compound giving the structural unit (B-1) contains the compound represented by formula (b1-1-1), the formula (b1-1-1) in the compound giving the structural unit (B-1) The proportion of the compound represented by) is preferably 50 to 100 mol%, more preferably 75 to 100 mol%, still more preferably 90 to 100 mol%, and particularly preferably 95 to 100 mol%.

The diamine component is a compound that imparts the above-described structural unit (B-2), a compound that imparts the above-described structural unit (B-3) within a range that does not impair colorless transparency and low retardation physical properties, and the above At least one compound selected from the group consisting of compounds that impart the structural unit (B-4) described above may also be included.

Examples of the compounds that impart the structural units (B-2) to (B-4) include compounds represented by formulas (b-2) to (b-4), respectively, but are not limited thereto, and have the same constitution. It may be a derivative thereof within the range to which a unit is given. Examples of the derivatives include diisocyanates corresponding to diamines represented by formulas (b-2) to (b-4). As the compound which imparts structural units (B-2) to (B-4), compounds (that is, diamine) represented by formulas (b-2) to (b-4), respectively, are preferable.

When the diamine component contains a compound that imparts at least one structural unit selected from the group consisting of structural units (B-2) to (B-4), structural units (B-2) to (B-4) Although it may contain a compound which gives two or more kinds of structural units, it is preferable to include a compound that gives one kind of structural unit among the structural units (B-2) to (B-4). That is, it is preferable that the structural unit B contains the compound which gives the structural unit (B-2), the compound which gives the structural unit (B-3), or the compound which gives the structural unit (B-4).

When the diamine component contains a compound that imparts at least one structural unit selected from the group consisting of structural units (B-2) to (B-4), the compound is preferably 5 to 95 mol%, It contains more preferably 7 to 85 mol%, still more preferably 10 to 55 mol%, particularly preferably 12 to 25 mol%.

The diamine component may contain compounds other than the compound which imparts structural units (B-1) to (B-4), and as the compound, the above-described aromatic diamine, alicyclic diamine, and aliphatic diamine, and these Derivatives (diisocyanate, etc.) are mentioned.

The number of compounds other than the compound which imparts structural units (B-1) to (B-4) optionally contained in the diamine component may be one or two or more.

In the present invention, it is preferable that the amount 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 with respect to 1 mole of the tetracarboxylic acid component.

In addition, in the present invention, in the production of the polyimide resin, in addition to the above-described tetracarboxylic acid component and diamine component, an end-sealing agent can also be used. As the terminal sealing agent, monoamines or dicarboxylic acids are preferable. The amount of the terminal sealing agent to be introduced is preferably 0.0001 to 0.1 mol, and particularly preferably 0.001 to 0.06 mol with respect to 1 mol of the tetracarboxylic acid component. Examples of monoamine end caps include methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, and 3-methylbenzylamine , 3-ethylbenzylamine, aniline, 3-methylaniline, and 4-methylaniline are recommended. Among these, benzylamine and aniline can be used suitably. As the dicarboxylic acid terminal sealing agent, dicarboxylic acids are preferable, and a part thereof may be cyclized. For example, phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenone dicarboxylic acid, 3,4-benzophenone dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid and the like are recommended. Among these, phthalic acid and phthalic anhydride can be suitably used.

There is no restriction|limiting in particular in the method of making the said tetracarboxylic acid component and the 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 introduced into a reactor, stirred at room temperature to 80°C for 0.5 to 30 hours, and then heated to perform an imidation reaction, ( 2) After dissolving the diamine component and the reaction solvent in the reactor, the tetracarboxylic acid component is added and, if necessary, stirred at room temperature to 80° C. for 0.5 to 30 hours, and then heated to perform an imidation reaction, (3) A method of introducing a tetracarboxylic acid component, a diamine component, and a reaction solvent into a reactor, and immediately raising the temperature to perform an imidation reaction, etc. are mentioned.

The reaction solvent used in the production of the polyimide resin may be any one capable of dissolving the resulting polyimide without inhibiting the imidation reaction. For example, an aprotic solvent, a phenolic solvent, an ether solvent, a carbonate solvent, and the like can be mentioned.

Specific examples of the aprotic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 1,3-dimethylimidazoli Amide solvents such as dinon and tetramethylurea, lactone solvents such as γ-butyrolactone and γ-valerolactone, phosphorus-containing amide solvents such as hexamethylphospholicamide and hexamethylphosphinetriamide, dimethylsulfone , Sulfur-containing solvents such as dimethyl sulfoxide and sulfolane, ketone-based solvents such as acetone, methyl ethyl ketone, cyclohexanone, and methylcyclohexanone, amine solvents such as picoline and pyridine, acetic acid (2-methoxy- And ester solvents such as 1-methylethyl).

As a specific example of a phenolic solvent, 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 solvent include 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, 1,2-bis(2-methoxyethoxy)ethane, and bis[2-(2-me) ether. Oxyethoxy)ethyl] ether, tetrahydrofuran, and 1,4-dioxane.

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

Among the above reaction solvents, amide-based solvents or lactone-based solvents are preferable. The above reaction solvents may be used alone or in combination of two or more.

In the imidation reaction, it is preferable to perform the reaction while removing water generated during production using a Dean Stark apparatus or the like. By performing such an operation, the degree of polymerization and the imidation ratio can be further increased.

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

As a base catalyst, pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine, tripropylamine, tributylamine , Triethylenediamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline, and other organic base catalysts, and inorganic bases such as potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium hydrogen carbonate and sodium hydrogen carbonate Catalysts.

Further, examples of the acid catalyst include crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methylbenzoic acid, oxyanic acid, terephthalic acid, benzenesulfonic acid, paratoluenesulfonic acid, naphthalenesulfonic acid, and the like. The imidation catalyst described above 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, more preferably an organic base catalyst, still more preferably at least one selected from triethylamine and triethylenediamine, and triethylamine. It is particularly preferable to use or to use a combination of triethylamine and triethylenediamine.

The temperature of the imidation reaction is preferably 120 to 250°C, more preferably 160 to 200°C, from the viewpoint of the reaction rate and suppression of gelation and the like. In addition, the reaction time is preferably 0.5 to 10 hours after the start of outflow of the generated 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 and an organic solvent of the present invention, and the polyimide resin is dissolved in the organic solvent.

The organic solvent is not particularly limited as long as the polyimide resin is dissolved, but it is preferable to use the above-described compounds alone or in combination of two or more as the reaction solvent used in the production of the polyimide resin.

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

The polyimide varnish of the present invention may be obtained by dissolving the polyimide resin of the present invention in a low-boiling solvent having a boiling point of 130°C or lower. By using the low-boiling solvent as the organic solvent, the heating temperature when producing the polyimide film described later can be lowered. Examples of the low-boiling solvent include carbon tetrachloride, dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, and acetone, among which dichloromethane is preferable.

Since the polyimide resin of the present invention has solvent solubility, it can be obtained as a varnish of high concentration stable at room temperature. The polyimide varnish of the present invention preferably contains 5 to 40 mass% of the polyimide resin of the present invention, and more preferably contains 10 to 30 mass%. The viscosity of the polyimide varnish is preferably 1 to 200 Pa·s, and more preferably 5 to 150 Pa·s. 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 is an inorganic filler, an adhesion promoter, a release agent, a flame retardant, an ultraviolet stabilizer, a surfactant, a leveling agent, an antifoaming agent, an optical brightener, a crosslinking agent, It may also contain various additives such as a polymerization initiator and a photosensitizer.

The method for producing the polyimide varnish of the present invention is not particularly limited, and a known method can be applied.

[Polyimide Film]

The polyimide film of the present invention contains the polyimide resin of the present invention. Therefore, the polyimide film of the present invention is excellent in colorless transparency and further low retardation. The suitable physical property values of the polyimide film of the present invention are as described above.

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 applying the polyimide varnish of the present invention onto a smooth support such as a glass plate, a metal plate, or plastic, or forming a film, an organic solvent such as a reaction solvent or a diluting solvent contained in the varnish is heated. A method of removing by If necessary, a release agent may be previously applied to the surface of the support.

As a method of removing the organic solvent contained in the varnish by heating, the following method is preferable. That is, after evaporating the organic solvent at a temperature of 120°C or lower to form a self-supporting film, the self-supporting film is peeled from the support, the end of the self-supporting film is fixed, and the temperature is above the boiling point of the used organic solvent. It is preferable to dry it in to prepare a polyimide film. In addition, it is preferable to dry it in a nitrogen atmosphere. The pressure in the dry atmosphere may be any of reduced pressure, normal pressure, and pressurization. The heating temperature when drying the self-supporting film to prepare a polyimide film is not particularly limited, but is preferably 200 to 400°C.

When the organic solvent contained in the polyimide varnish of the present invention is a low boiling point solvent having a boiling point of 130°C or less, the heating temperature of the self-supporting film is preferably 100 to 180°C. Further, it is preferable to perform an annealing treatment in which the polyimide film obtained by removing the low boiling point solvent is further heated at a temperature equal to or higher than the glass transition temperature.

Further, the polyimide film of the present invention can also be produced using a polyamic acid varnish obtained by dissolving a polyamic acid in an organic solvent.

The polyamic acid contained in the polyamic acid varnish is a precursor of the polyimide resin of the present invention, a compound that provides the structural unit (A-1) and the structural unit (A-2) described above. It is a product of a polyaddition reaction of a tetracarboxylic acid component containing at least one selected from the group consisting of compounds and a diamine component containing a compound that imparts the above-described structural unit (B-1). By imidizing this polyamic acid (dehydration ring closure), the final product, the polyimide resin of the present invention, is obtained.

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

In the present invention, the polyamic acid varnish contains at least one selected from the group consisting of a compound that imparts the structural unit (A-1) described above and a compound that imparts the structural unit (A-2) described above. It may be a polyamic acid solution itself obtained by polyaddition reaction of a tetracarboxylic acid component and a diamine component containing a compound that imparts the above-described structural unit (B-1) in a reaction solvent, or the polyamic acid It may be that a diluent was added again to the solution.

There is no particular limitation on the method of producing a polyimide film using a polyamic acid varnish, and a known method can be used. For example, polyamic acid varnish is coated on a smooth support such as a glass plate, metal plate, or plastic, or formed into a film, and organic solvents such as reactive solvents or diluting solvents contained in the varnish are removed by heating. Thus, a polyamic acid film is obtained, and a polyimide film can be produced by imidizing the polyamic acid in the polyamic acid film by heating.

The heating temperature when drying the polyamic acid varnish to obtain a polyamic acid film is preferably 50 to 120°C. When the polyamic acid is imidized by heating, the heating temperature is preferably 200 to 400°C.

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

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

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

Example

Hereinafter, the present invention will be described in detail through examples. However, the present invention is not limited to these examples at all.

The solid content concentration of the varnish obtained in Examples and Comparative Examples and the physical properties of each film were measured by the methods shown below.

(1) Solid content concentration

The measurement of the solid content concentration of the varnish was performed by heating a sample at 280° C. x 120 min with a small electric furnace "MMF-1" manufactured by Asone Co., Ltd., and calculated from the difference in mass of the sample before and after heating.

(2) Film thickness

The film thickness was measured using a micrometer manufactured by Mitsutoyo Co., Ltd.

(3) Total light transmittance, yellow index (YI), haze

The total light transmittance, YI, and haze were measured using a color and turbidity simultaneous measuring instrument "COH400" manufactured by Nippon Electric Co., Ltd. The measurement of the total light transmittance and YI was based on JIS K7361-1:1997, and the measurement of haze was based on JIS K7136:2000.

(4) Thickness phase difference (Rth)

The thickness phase difference (Rth) was measured using an ellipsometer "M-220" manufactured by Nippon Spectroscopic Co., Ltd. The value of the thickness phase difference at a measurement wavelength of 550 nm was measured. On the other hand, Rth is expressed by the following formula when the largest 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=[{(nx+ny)/2}-nz]×d

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

<Tetracarboxylic acid component>

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

CpODA: Novonan-2-spiro-α-cyclopentanone-α'-spiro-2''-novonane-5,5'',6,6''-tetracarboxylic dianhydride (manufactured by JXTG Energy Co., Ltd.; Compound represented by formula (a-3))

<Diamine component>

BisAM: 1,3-bis[2-(4-aminophenyl)-2-propyl]benzene (manufactured by Mitsui Chemical Fine Co., Ltd., a compound represented by formula (b1-1-1))

TPER: 1,3-bis(4-aminophenoxy)benzene (Wakayama Seika Industrial Co., Ltd. make, compound represented by formula (b1-1-2))

APBN: 1,3-bis(3-aminophenoxy)benzene (manufactured by Mitsui Chemicals Co., Ltd., a compound represented by formula (b1-1-3))

TPEQ: 1,4-bis(4-aminophenoxy)benzene (manufactured by Wakayama Seika Industrial Co., Ltd.)

3,5-DABA: 3,5-diaminobenzoic acid (manufactured by Nippon Pure Chemical Co., Ltd.)

BAPA: 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (manufactured by Wakayama Seika Industrial Co., Ltd.)

ODA: 4,4'-diaminodiphenyl ether (manufactured by Wakayama Seika Industrial Co., Ltd., a compound represented by formula (b-3))

BAPP: 2,2-bis[4-(4-aminophenoxy)phenyl]propane (Wakayama Seika Industrial Co., Ltd. make, compound represented by formula (b-2))

3,4'-DPE: 3,4'-diaminodiphenyl ether (manufactured by Wakayama Seika Industrial Co., Ltd.)

BisAP: 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene (manufactured by Mitsui Chemical Fine Co., Ltd., a compound represented by formula (b-4))

Details of the solvent and catalyst used in Examples and Comparative Examples are as follows.

γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.)

N,N-dimethylacetamide (manufactured by Mitsubishi Gas Chemical Co., Ltd.)

Triethylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.)

Triethylamine (manufactured by Kanto Chemical Co., Ltd.)

<Example 1>

As a reaction device, a 0.3 L five-necked glass round bottom flask equipped with a stainless steel half-moon stirring blade, a nitrogen introduction tube, a Dean Stark device with a cooling tube, a thermometer, and a glass end cap was used, and in this round bottom flask, 25.920 g (0.075 mol) of BisAM, 35.0 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation), and as a catalyst, 0.048 g of triethylenediamine and 3.80 g of triethylamine were added, and stirred at 150 rpm under a nitrogen atmosphere. It heated up to 70 degreeC while doing, and obtained the solution. To this solution, 16.830 g (0.075 mol) of HPMDA and 17.1 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 200°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 200°C for 5.5 hours. After 67.71 g of N,N-dimethylacetamide was added, the mixture was stirred at about 100°C for about 1 hour to obtain a homogeneous polyimide varnish having a solid content concentration of 25% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 30 μm. Table 1 shows the evaluation results of this polyimide film.

<Example 2>

Using the same reaction apparatus as in Example 1, in a round-bottom flask, 24.899 g (0.085 mol) of APBN, 40.0 g of γ-butyrolactone, and 4.30 g of triethylamine as a catalyst were added, and in a nitrogen atmosphere, The temperature was raised to 70° C. while stirring at 150 rpm to obtain a solution. To this solution, 19.074 g (0.085 mol) of HPMDA and 13.7 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 190°C for 3.3 hours. After the addition of 41.6 g of N,N-dimethylacetamide, the mixture was stirred at about 100°C for about 1 hour to obtain a homogeneous polyimide varnish having a solid content concentration of 30% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 47 μm. Table 1 shows the evaluation results of this polyimide film.

<Example 3>

Using the same reaction apparatus as in Example 1, in a round bottom flask, 24.337 g (0.083 mol) of TPER, 45.1 g of γ-butyrolactone, and 2.11 g of triethylamine as a catalyst were added, and under a nitrogen atmosphere, The temperature was raised to 70° C. while stirring at 150 rpm to obtain a solution. To this solution, 18.701 g (0.083 mol) of HPMDA and 19.4 g of N,N-dimethylacetamide were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. . The distilled component was collected, and the temperature in the reaction system was maintained at 190°C for 2.7 hours. After 64.5 g of N,N-dimethylacetamide was added, the mixture was stirred at about 100°C for about 1 hour to obtain a uniform polyimide varnish having a solid content concentration of 24% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 31 μm. Table 1 shows the evaluation results of this polyimide film.

<Comparative Example 1>

Using the same reaction apparatus as in Example 1, in a round bottom flask, 23.370 g (0.080 mol) of TPEQ, 40.4 g of γ-butyrolactone, and 0.41 g of triethylamine as a catalyst were added, and under a nitrogen atmosphere, The temperature was raised to 80° C. while stirring at 150 rpm to obtain a solution. To this solution, 17.934 g (0.080 mol) of HPMDA and 10.1 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 200° C. over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 200°C for 2.5 hours. After addition of 103.3 g of N,N-dimethylacetamide, the mixture was stirred at about 100°C for about 1 hour to obtain a uniform polyimide varnish having a solid content concentration of 20% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 18 μm. Table 1 shows the evaluation results of this polyimide film.

<Comparative Example 2>

Using the same reaction apparatus as in Example 1, in a round bottom flask, 28.559 g (0.188 mol) of 3,5-DABA, 132.1 g of γ-butyrolactone, and 0.95 g of triethylamine as a catalyst were added, In a nitrogen atmosphere, the temperature was raised to 70° C. while stirring at 150 rpm to obtain a solution. To this solution, 42.132 g (0.188 mol) of HPMDA and 33.03 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 190°C for 5.0 hours. After 90.86 g of γ-butyrolactone was added, the mixture was stirred at about 100°C for about 1 hour to obtain a uniform polyimide varnish having a solid content concentration of 20% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 29 μm. Table 1 shows the evaluation results of this polyimide film.

<Comparative Example 3>

Using the same reaction apparatus as in Example 1, in a round-bottom flask, 42.278 g (0.115 mol) of BAPA, 81.8 g of γ-butyrolactone, and 0.58 g of triethylamine as a catalyst were put in a round bottom flask, and under a nitrogen atmosphere, The temperature was raised to 70° C. while stirring at 150 rpm to obtain a solution. To this solution, 25.877 g (0.115 mol) of HPMDA and 20.4 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 190°C for 5.0 hours. After 153.8 g of γ-butyrolactone was added, the mixture was stirred at about 100°C for about 1 hour to obtain a uniform polyimide varnish having a solid content concentration of 20% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 26 μm. Table 1 shows the evaluation results of this polyimide film.

<Comparative Example 4>

Using the same reaction apparatus as in Example 1, in a round-bottom flask, 20.024 g (0.100 mol) of ODA, 45.0 g of γ-butyrolactone, and 1.52 g of triethylamine as a catalyst were added, and in a nitrogen atmosphere, The temperature was raised to 70° C. while stirring at 150 rpm to obtain a solution. To this solution, 22.417 g (0.100 mol) of HPMDA and 18.7 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 200°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 200°C for 4.0 hours. After 91.7 g of N,N-dimethylacetamide was added, the mixture was stirred at about 100°C for about 1 hour to obtain a uniform polyimide varnish having a solid content concentration of 20% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 40 μm. Table 1 shows the evaluation results of this polyimide film.

<Comparative Example 5>

Using the same reaction apparatus as in Example 1, in a round-bottom flask, 43.745 g (0.107 mol) of BAPP, 81.4 g of γ-butyrolactone, and 0.54 g of triethylamine as a catalyst were added, and in a nitrogen atmosphere, The temperature was raised to 70° C. while stirring at 150 rpm to obtain a solution. To this solution, 23.887 g (0.107 mol) of HPMDA and 20.3 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Corporation) were added in batches, followed by heating with a mantle heater, and the temperature in the reaction system was increased over about 20 minutes. It was raised to 190°C. The distilled component was collected, and the temperature in the reaction system was maintained at 190°C for 4.0 hours. After 154.2 g of γ-butyrolactone (manufactured by Mitsubishi Chemical Co., Ltd.) was added, the mixture was stirred at about 100°C for about 1 hour to obtain a uniform polyimide varnish having a solid content concentration of 20% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 33 μm. Table 1 shows the evaluation results of this polyimide film.

<Comparative Example 6>

Using the same reaction apparatus as in Example 1, in a round bottom flask, 20.024 g (0.100 mol) of 3,4'-DPE, 45.0 g of γ-butyrolactone, and 0.065 g of triethylenediamine as a catalyst, 1.52 g of triethylamine was added, and the temperature was raised to 70°C while stirring at 150 rpm under a nitrogen atmosphere to obtain a solution. To this solution, 22.417 g (0.100 mol) of HPMDA and 18.7 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 200°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 200°C for 4.0 hours. After 91.7 g of N,N-dimethylacetamide was added, the mixture was stirred at about 100°C for about 1 hour to obtain a uniform polyimide varnish having a solid content concentration of 20% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 25 μm. Table 1 shows the evaluation results of this polyimide film.

[Table 1-1]

<Example 4>

Using the same reaction apparatus as in Example 1, in a round bottom flask, 14.417 g (0.072 mol) of ODA, 6.201 g (0.018 mol) of BisAM, 40.0 g of γ-butyrolactone, and triethylenediamine as a catalyst Into 0.050g and 4.55g of triethylamine, the temperature was raised to 70°C while stirring at 150 rpm under a nitrogen atmosphere to obtain a solution. To this solution, 20.175 g (0.090 mol) of HPMDA and 10.0 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 200°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 200°C for 0.7 hours. After the addition of 38.0 g of N,N-dimethylacetamide, the mixture was stirred at about 100°C for about 1 hour to obtain a homogeneous polyimide varnish having a solid content concentration of 30% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 42 μm. Table 1 shows the evaluation results of this polyimide film.

<Example 5>

Using the same reaction apparatus as in Example 1, in a round bottom flask, 10.012 g (0.050 mol) of ODA, 17.225 g (0.050 mol) of BisAM, 48.7 g of γ-butyrolactone, and as a catalyst, triethylenediamine Was added 0.056 g and 5.06 g of triethylamine, and the mixture was heated to 70° C. while stirring at 150 rpm under a nitrogen atmosphere to obtain a solution. To this solution, 22.417 g (0.10 mol) of HPMDA and 12.2 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 200°C over about 20 minutes. The distilled components were collected, and the temperature in the reaction system was maintained at 200°C for 0.6 hours. After 77.8 g of N,N-dimethylacetamide was added, the mixture was stirred at about 100°C for about 1 hour to obtain a homogeneous polyimide varnish having a solid content concentration of 25% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 34 μm. Table 1 shows the evaluation results of this polyimide film.

<Example 6>

As a reaction apparatus, the same 3.0 L apparatus as in Example 1 was used, and in a round bottom flask, 23.228 g (0.116 mol) of ODA, 159.848 g (0.464 mol) of BisAM, 307.0 g of γ-butyrolactone, and As a catalyst, 0.325 g of triethylenediamine and 29.345 g of triethylamine were put, and the temperature was raised to 70°C while stirring at 150 rpm under a nitrogen atmosphere to obtain a solution. To this solution, 130.019 g (0.580 mol) of HPMDA and 76.8 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 200°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 200°C for 2.0 hours. After addition of 300.0 g of N,N-dimethylacetamide, the mixture was stirred at about 100°C for about 1 hour to obtain a homogeneous polyimide varnish having a solid content concentration of 30% by mass.

Subsequently, the obtained polyimide varnish was applied on a PET substrate, the temperature was raised step by step, and maintained at a maximum temperature of 140° C. for about 2 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dry film having self-supporting properties. . Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 32 μm. Table 1 shows the evaluation results of this polyimide film.

[Table 1-2]

<Example 7>

Using the same reaction apparatus as in Example 1, in a round-bottom flask, 27.259 g (0.066 mol) of BAPP, 5.719 g (0.017 mol) of BisAM, 50.6 g of γ-butyrolactone, and triethylenediamine as a catalyst Was added 0.047 g of triethylamine and 4.20 g of triethylamine, and the mixture was heated to 70° C. while stirring at 150 rpm under a nitrogen atmosphere to obtain a solution. To this solution, 18.606 g (0.083 mol) of HPMDA and 12.6 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 200°C over about 20 minutes. The distilled components were collected, and the temperature in the reaction system was maintained at 200°C for 0.5 hours. After 83.0 g of N,N-dimethylacetamide was added, the mixture was stirred at about 100°C for about 1 hour to obtain a homogeneous polyimide varnish having a solid content concentration of 25% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 47 μm. Table 1 shows the evaluation results of this polyimide film.

<Example 8>

Using the same reaction apparatus as in Example 1, in a round bottom flask, 16.421 g (0.040 mol) of BAPP, 13.780 g (0.040 mol) of BisAM, 40.0 g of γ-butyrolactone, and triethylenediamine as a catalyst 0.044 g and 4.05 g of triethylamine were added, and the mixture was heated to 70° C. while stirring at 150 rpm under a nitrogen atmosphere to obtain a solution. To this solution, 17.934 g (0.080 mol) of HPMDA and 18.8 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 190°C for 2.2 hours. After 122.2 g of N,N-dimethylacetamide was added, the mixture was stirred at about 100°C for about 1 hour to obtain a uniform polyimide varnish having a solid content concentration of 20% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 30 μm. Table 1 shows the evaluation results of this polyimide film.

<Example 9>

Using the same reaction apparatus as in Example 1, in a round-bottom flask, 6.568 g (0.016 mol) of BAPP, 22.048 g (0.064 mol) of BisAM, 30.0 g of γ-butyrolactone, and triethylenediamine as a catalyst 0.044 g and 4.05 g of triethylamine were added, and the mixture was heated to 70° C. while stirring at 150 rpm under a nitrogen atmosphere to obtain a solution. To this solution, 17.934 g (0.080 mol) of HPMDA and 16.6 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. The distilled component was collected, and the temperature in the reaction system was maintained at 190°C for 1.4 hours. After 84.4 g of N,N-dimethylacetamide was added, the mixture was stirred at about 100°C for about 1 hour to obtain a homogeneous polyimide varnish having a solid content concentration of 25% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 35 μm. Table 1 shows the evaluation results of this polyimide film.

[Table 1-3]

<Example 10>

Using the same reaction apparatus as in Example 1, in a round-bottom flask, 27.560 g (0.080 mol) of BisAM, 30.8 g of γ-butyrolactone, and 0.022 g of triethylenediamine and 2.02 of triethylamine as a catalyst. g was put, and the temperature was raised to 70° C. while stirring at 150 rpm under a nitrogen atmosphere to obtain a solution. To this solution, 8.967 g (0.040 mol) of HPMDA, 15.375 g (0.040 mol) of CpODA, and 32.9 g of γ-butyrolactone were added in batches, respectively, followed by heating with a mantle heater, and the reaction system over about 20 minutes I raised my temperature to 190°C. The distilled component was collected, and the temperature in the reaction system was maintained at 190°C for 2.0 hours. After addition of 88.0 g of N,N-dimethylacetamide, the mixture was stirred at about 100°C for about 1 hour to obtain a homogeneous polyimide varnish having a solid content concentration of 25% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 38 μm. Table 1 shows the evaluation results of this polyimide film.

<Example 11>

Using the same reaction apparatus as in Example 1, in a round-bottom flask, 13.780 g (0.040 mol) of BisAP, 13.780 g (0.040 mol) of BisAM, 40.0 g of γ-butyrolactone, and triethylenediamine as a catalyst 0.044 g and 4.05 g of triethylamine were added, and the mixture was heated to 70° C. while stirring at 150 rpm under a nitrogen atmosphere to obtain a solution. To this solution, 17.934 g (0.080 mol) of HPMDA and 15.6 g of γ-butyrolactone were added in batches, respectively, and then heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. The distilled components were collected, and the temperature in the reaction system was maintained at 190°C for 3.5 hours. After 114.8 g of N,N-dimethylacetamide was added, the mixture was stirred at about 100°C for about 1 hour to obtain a uniform polyimide varnish having a solid content concentration of 20% by mass.

Subsequently, the obtained polyimide varnish was applied onto a PET substrate, held at 100° C. for 20 minutes, and the solvent was volatilized to obtain a colorless, transparent primary dried film having self-supporting properties. Again, this film was fixed to a stainless steel frame, and the solvent was removed by drying for 20 minutes in an air atmosphere at 210°C to obtain a film having a thickness of 35 μm. Table 1 shows the evaluation results of this polyimide film.

[Table 1-4]

As shown in Table 1, the polyimide films of Examples 1 to 11 produced using a specific tetracarboxylic acid component and a specific diamine component were excellent in colorless transparency and further had low retardation.

On the other hand, the polyimide films of Comparative Examples 1 to 6, which do not use a diamine that imparts the structural unit (B-1) as a diamine component, compared to the polyimide films of Examples 1 to 3, the retardation value (Rth) This was great.

The polyimide films of Examples 4 to 6 in which BisAM and ODA were used in combination as a diamine acid component, compared with the polyimide film of Comparative Example 4 prepared using only ODA, significantly reduced the retardation value (Rth).

The polyimide films of Examples 7 to 9 in which BisAM and BAPP were used in combination as a diamine acid component were compared with the polyimide film of Comparative Example 5 prepared using only BAPP, and the retardation value (Rth) was significantly reduced.

Industrial applicability

The polyimide film of the present invention is suitably used as a film for various members such as color filters, flexible displays, semiconductor parts, and optical members. The polyimide film of the present invention is particularly suitably used as a substrate for an image display device such as a liquid crystal display or an OLED display.

Claims (9)

As a polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from diamine,
Structural unit A is a structural unit (A-1) derived from a compound represented by the following formula (a-1), and a structural unit (A-2) derived from a compound represented by the following formula (a-2). It contains at least one constituent unit selected from the group consisting of,
Structural unit B is at least one selected from the group consisting of a structural unit derived from a compound represented by the following general formula (b1-1), and a structural unit derived from a compound represented by the following general formula (b2-1) Polyimide resin containing a structural unit (B-1).
[Formula 1]

(In the formula, X ¹ to X ⁴ are each independently a single bond, an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, -S-, -SO-, -SO ₂ -, -O- Or -CO-.) The method of claim 1,
The polyimide resin, wherein the proportion of the structural unit (B-1) in the structural unit B is 5 to 100 mol%. The method according to claim 1 or 2,
A polyimide resin, wherein the structural unit A contains the structural unit (A-1), and the proportion of the structural unit (A-1) in the structural unit A is 45 to 100 mol%. The method according to any one of claims 1 to 3,
The structural unit (B-1) is a structural unit derived from a compound represented by the following formula (b1-1-1), a structural unit derived from a compound represented by the following formula (b1-1-2), and the following formula: A polyimide resin containing at least one structural unit selected from the group consisting of structural units derived from the compound represented by (b1-1-3).
[Formula 2]

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

The method of claim 5,
A polyimide resin, wherein the proportion of the total of the structural unit (B-2), the structural unit (B-3), and the structural unit (B-4) in the structural unit B is 5 to 95 mol%. The method according to any one of claims 1 to 6,
A polyimide resin in which the structural unit A further contains a structural unit (A-3) derived from a compound represented by the following formula (a-3).
[Formula 4]

A polyimide varnish obtained by dissolving the polyimide resin according to any one of claims 1 to 7 in an organic solvent. A polyimide film containing the polyimide resin according to any one of claims 1 to 7.