KR20230066345A - Polymer composition, varnish, and polyimide film - Google Patents

Abstract

(식(1) 중, X¹은 지환구조 혹은 방향족환을 갖는 4가의 기이다. 식(2) 중, X²는 지환구조 혹은 방향족환을 갖는 4가의 기이고, R¹ 및 R²는 각각 독립적으로 수소, 탄소수 1~6의 알킬기, 또는 탄소수 3~9의 알킬실릴기이다. 식(3) 중, R³은, 탄소수 1~30의 알킬기, 페닐기, 알콕시기, 아크릴로일기, 메타크릴로일기, 아크릴로일옥시에틸기, 및 메타크릴로일옥시에틸기로 이루어지는 군으로부터 선택되는 적어도 하나이고, n은 0~2이다.)Polymer (X) containing at least one selected from the group consisting of a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2), and a compound represented by the following general formula (3) A polymer composition comprising (Y).

(In Formula (1), X ¹ is a tetravalent group having an alicyclic structure or an aromatic ring. In Formula (2), X ² is a tetravalent group having an alicyclic structure or an aromatic ring, and R ¹ and R ² are each Independently, it is hydrogen, an alkyl group having 1 to 6 carbon atoms, or ^an alkylsilyl group having 3 to 9 carbon atoms. At least one selected from the group consisting of a loyl group, an acryloyloxyethyl group, and a methacryloyloxyethyl group, and n is 0 to 2.)

Description

Polymer composition, varnish, and polyimide film

The present invention relates to polymer compositions, varnishes, and polyimide films.

Since polyimide resins have excellent mechanical properties and heat resistance, various uses are being studied in fields such as electric/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 polyimide film substrates, and development of polyimide resins satisfying performance as optical materials is being conducted.

However, in recent years, due to the high functionality of electronic devices, there is a need for electronic parts to simultaneously satisfy various required performances. [0004] Therefore, attempts have been made to add new properties to the original properties of the resin or to improve the original properties by blending various additives with respect to polyimide resins used in displays.

For example, in Patent Document 1, in addition to heat resistance and mechanical properties, for the purpose of preventing crystallization and shortening the layer formation time, a specific polyamic acid and a specific phosphorus compound are included, and the polyamic acid has a maximum heating temperature A polyimide precursor composition capable of producing a polyimide film having a high water vapor transmission coefficient by heat-treating under conditions of 300 to 500° C. is disclosed.

Further, in Patent Document 2, for the purpose of obtaining a polyimide having transparency, heat resistance, and a low linear thermal expansion coefficient, a polyimide precursor having a specific repeating unit and a phosphorus atom are included, and the boiling point at 1 atm is higher than the decomposition temperature A polyimide precursor composition comprising a phosphorus compound that is low and is 350° C. or less is disclosed.

International Publication No. 2016/121817 International Publication No. 2015/080139

As described above, polyimide films are required to replace glass substrates, and high colorless transparency as well as mechanical properties and heat resistance are required. However, it is difficult to achieve both these performances, and it is difficult to prevent yellowing or the like even if heat resistance is improved by blending additives.

Further, in order to express colorless transparency in polyimide itself, aliphatic diamine or fluorine-containing diamine is generally used to suppress formation of charge transfer complexes between molecules or within molecules. However, under severe conditions such as 350 ° C. or higher in the process of manufacturing TFTs when manufacturing displays, for example, since aliphatic diamines lack rigidity compared to aromatic diamines, it is difficult to develop heat resistance, and Fluorinated diamine also loses colorless transparency at high temperatures. Therefore, a polyimide film having particularly excellent heat resistance and low yellowness has been demanded.

The present invention has been made in view of such a situation, and an object of the present invention is a polymer composition capable of obtaining a polyimide film having excellent heat resistance and low yellowness, a varnish containing the composition, and excellent heat resistance and yellowing It is to provide a polyimide film with a low degree.

The present inventors have found that a polymer composition containing a specific fluorodiamine, a polymer containing a repeating unit derived from tetracarboxylic acid having an alicyclic structure or an aromatic ring, and a specific phosphorus compound can solve the above problems, and completed the invention. I came to do it.

That is, the present invention relates to the following [1] to [7].

[1] Polymer (X) containing at least one selected from the group consisting of a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2), and the following general formula (3) A polymer composition comprising the indicated compound (Y).

[Formula 1]

(In Formula (1), X ¹ is a tetravalent group having an alicyclic structure or an aromatic ring.

In Formula (2), X ² is a tetravalent group having an alicyclic structure or an aromatic ring, and R ¹ and R ² are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.

In formula (3), R ³ is selected from the group consisting of an alkyl group having 1 to 30 carbon atoms, a phenyl group, an alkoxy group, an acryloyl group, a methacryloyl group, an acryloyloxyethyl group, and a methacryloyloxyethyl group. At least one, and n is 0 to 2.)

[2] The polymer composition according to [1] above, wherein the repeating unit represented by the formula (1) is 10 mol% or more with respect to all the repeating units of the polymer (X).

[3] The polymer composition according to [1] or [2] above, wherein the repeating unit represented by the formula (2) is 10 mol% or more with respect to all the repeating units of the polymer (X).

[4] The polymer composition according to any one of [1] to [3] above, wherein the content of compound (Y) is 10 ppm or more and 10,000 ppm or less relative to polymer (X).

[5] A varnish obtained by dissolving the polymer composition according to any one of [1] to [4] above in an organic solvent.

[6] A polyimide film obtained by applying the varnish according to [5] above on a support and heating it.

[7] A method for producing a polyimide film, wherein the varnish according to [5] above is applied onto a support and heated.

According to the present invention, a polymer composition capable of obtaining a polyimide film having excellent heat resistance and low yellowness, a varnish containing the composition, and a polyimide film having excellent heat resistance and low yellowness can be provided.

[Polymer composition]

The polymer composition of the present invention comprises a polymer (X) containing at least one selected from the group consisting of a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2), and the following general formula The compound (Y) represented by (3) is included.

[Formula 2]

(In Formula (1), X ¹ is a tetravalent group having an alicyclic structure or an aromatic ring.

In Formula (2), X ² is a tetravalent group having an alicyclic structure or an aromatic ring, and R ¹ and R ² are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.

In formula (3), R ³ is selected from the group consisting of an alkyl group having 1 to 30 carbon atoms, a phenyl group, an alkoxy group, an acryloyl group, a methacryloyl group, an acryloyloxyethyl group, and a methacryloyloxyethyl group. At least one, and n is 0 to 2.)

The reason why the polymer composition of the present invention is excellent as a raw material for a polyimide film and the obtained polyimide film has excellent properties such as excellent heat resistance and low yellowness is not certain, but it is considered as follows.

The polymer composition of the present invention contains a specific phosphorus compound, but the phosphorus compound coordinates with the terminal of a polyimide obtained by imidizing the polymer, or the terminal of the polyimide and the phosphorus compound react, particularly at a high temperature. It is thought that the side reaction or decomposition deterioration of can be suppressed, and furthermore, the desorption of fluorine derived from the fluorinated diamine can be suppressed, thereby achieving both heat resistance and low yellowness.

<Polymer (X)>

The polymer (X) contained in the polymer composition of the present invention contains at least one selected from the group consisting of a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2).

[Formula 3]

(In Formula (1), X ¹ is a tetravalent group having an alicyclic structure or an aromatic ring.

In Formula (2), X ² is a tetravalent group having an alicyclic structure or an aromatic ring, and R ¹ and R ² are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. )

The repeating unit represented by the general formula (1) contained in the polymer (X) is preferably a repeating unit represented by the following general formula (1-1).

[Formula 4]

(In Formula (1-1), X ¹ is a tetravalent group having an alicyclic structure or an aromatic ring.)

The repeating unit represented by the general formula (2) contained in the polymer (X) is preferably a repeating unit represented by the following general formula (2-1).

[Formula 5]

(In Formula (2-1), X ² is a tetravalent group having an alicyclic structure or an aromatic ring, and R ¹ and R ² are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl having 3 to 9 carbon atoms) It is Ki.)

The polymer (X) includes at least one selected from the group consisting of a repeating unit represented by the general formula (1) and a repeating unit represented by the general formula (2). It may contain only one of the repeating unit or the repeating unit represented by the above general formula (2), or may contain both.

That is, the polymer composition of the present invention may be a polyimide composition containing a polyimide containing a repeating unit represented by the following general formula (1) and a compound (Y) represented by the following general formula (3). ,

[Formula 6]

(In Formula (1), X ¹ is a tetravalent group having an alicyclic structure or an aromatic ring. In Formula (3), R ³ is an alkyl group having 1 to 30 carbon atoms, a phenyl group, an alkoxy group, an acryloyl group, or a methacrylic group. At least one selected from the group consisting of a loyl group, an acryloyloxyethyl group, and a methacryloyloxyethyl group, and n is 0 to 2.)

A polyamic acid composition containing a polyamic acid containing a repeating unit represented by the following general formula (2) and a compound (Y) represented by the following general formula (3) may also be used.

[Formula 7]

(In formula (2), X ² is a tetravalent group having an alicyclic structure or an aromatic ring, and R ¹ and R ² are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms. In Formula (3), R ³ is selected from the group consisting of an alkyl group having 1 to 30 carbon atoms, a phenyl group, an alkoxy group, an acryloyl group, a methacryloyl group, an acryloyloxyethyl group, and a methacryloyloxyethyl group. is at least one, and n is 0 to 2.)

The polymer (X) preferably contains a repeating unit represented by the above general formula (1), more preferably a repeating unit represented by the above general formula (1) and a repeating unit represented by the above general formula (2). Includes both sides of the unit.

In the formula (1), X ¹ is a tetravalent group having an alicyclic structure or an aromatic ring. X ¹ is preferably obtained by removing two dicarboxylic acid anhydride moieties (four carboxy group moieties) from tetracarboxylic dianhydride, which is a raw material for constituent unit A derived from tetracarboxylic dianhydride described later.

In the formula (2), X ² is a tetravalent group having an alicyclic structure or an aromatic ring. X ² is preferably obtained by removing two dicarboxylic acid anhydride moieties (four carboxy group moieties) from tetracarboxylic dianhydride, which is a raw material for constituent unit A derived from tetracarboxylic dianhydride described later.

In the formula (2), R ¹ and R ² are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms, preferably hydrogen.

(Configuration of Polymer (X))

As described above, the polymer (X) contains at least one selected from the group consisting of a repeating unit represented by the above general formula (1) and a repeating unit represented by the above general formula (2), ), or may contain only one of the repeating units represented by the general formula (2), or may contain both. In particular, from the viewpoint of reducing yellowness and improving transparency, the formula The repeating unit represented by (1) is preferably 10 mol% or more, more preferably 30 mol% or more, still more preferably 50 mol% or more, based on all repeating units of the polymer (X). , More preferably, it is 70 mol% or more, and even more preferably 90 mol% or more and 100 mol% or less.

In addition, from the viewpoint of improving heat resistance while maintaining low yellowness, the repeating unit represented by the formula (2) is preferably 10 mol% or more with respect to all repeating units of the polymer (X), and more It is preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 70 mol% or more, still more preferably 90 mol% or more, and 100 mol% or less.

Further, when both the repeating unit represented by the general formula (1) and the repeating unit represented by the general formula (2) are included, the repeating unit represented by the general formula (1) and the repeating unit represented by the general formula (2) The molar ratio of repeating units represented by [(1)/(2)] is preferably 10/90 to 70/30, more preferably 20/80 to 60/40, still more preferably 25/75 to 55 /45.

<Each structural unit of polymer (X)>

Polymer (X) contains at least one selected from the group consisting of a repeating unit represented by the formula (1) and a repeating unit represented by the formula (2) explained below.

Polymer (X) has structural unit A derived from tetracarboxylic dianhydride and structural unit B derived from diamine.

On the other hand, in the repeating unit represented by the general formula (1), the structural unit A and the structural unit B form an imide structure, and in the repeating unit represented by the general formula (2), the structural unit A and the structural unit Unit B forms an amide acid structure, and structural units derived from tetracarboxylic dianhydride are collectively referred to as structural unit A and structural units derived from diamine as structural unit B.

(unit A)

Structural unit A is a structural unit derived from tetracarboxylic dianhydride, and is at least one selected from the group consisting of structural units derived from alicyclic tetracarboxylic dianhydride and structural units derived from aromatic tetracarboxylic dianhydride; , From the viewpoint of low yellowness and transparency, it is preferably a structural unit derived from an alicyclic tetracarboxylic dianhydride, and from the viewpoint of heat resistance, it is preferably a structural unit derived from an aromatic tetracarboxylic dianhydride.

Examples of the alicyclic tetracarboxylic dianhydride giving structural units derived from the alicyclic tetracarboxylic dianhydride include 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 1,2,3,4-cyclohexane. Butanetetracarboxylic dianhydride, norbonane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbonane-5,5'',6,6''-tetracarboxylic dianhydride, Bicyclo[2.2.2]octa-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyltetracarboxylic dianhydride, 5,5'-(1,4-phenylene)-bis [hexahydro-4,7-methanoisobenzofuran-1,3-dione], 5,5'-bis-2-norbornene-5,5',6,6'-tetracarboxylic acid-5,5',6,6 '-dianhydrides, or regioisomers thereof, and the like are exemplified.

Among these, from the viewpoint of low yellowness and transparency, a compound represented by the following formula (a1) is preferred, and the structural unit A is preferably a structural unit (A1) derived from a compound represented by the formula (a1). include

[Formula 8]

The compound represented by formula (a1) is norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbonane-5,5'',6,6''-tetracarboxylic acid It is dianhydride.

Examples of the aromatic tetracarboxylic dianhydride giving structural units derived from aromatic tetracarboxylic dianhydride include biphenyltetracarboxylic dianhydride (BPDA) and 9,9-bis(3,4-dicarboxyphenyl)fluorene. Dianhydride (BPAF), pyromellitic dianhydride, 3,3',4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 3,3',4,4'-diphenylsulfotetracarboxylic acid dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2,2',3,3'-benzophenone tetracarboxylic dianhydride, and the like.

Among these, from the viewpoint of achieving both heat resistance and low yellowness, it is preferably at least one selected from the group consisting of a compound represented by the following formula (a2) and a compound represented by the following formula (a3), more preferably It is a compound represented by the following formula (a2).

That is, the structural unit A is preferably selected from the group consisting of a structural unit (A2) derived from a compound represented by the following formula (a2) and a structural unit (A3) derived from a compound represented by the following formula (a3) It contains at least one, more preferably a structural unit (A2) derived from a compound represented by the following formula (a2).

[Formula 9]

The compound represented by the formula (a2) is biphenyltetracarboxylic dianhydride (BPDA), and specific examples thereof include 3,3',4,4'-biphenyltetracarb represented by the following formula (a2s) 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA) represented by basal acid dianhydride (s-BPDA), the following formula (a2a), 2 represented by the following formula (a2i), and 2',3,3'-biphenyltetracarboxylic dianhydride (i-BPDA). Especially, 3,3',4,4'-biphenyl tetracarboxylic dianhydride (s-BPDA) represented by the following formula (a2s) is preferable.

[Formula 10]

The compound represented by formula (a3) is 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride (BPAF).

Structural unit A may also contain structural units other than aromatic tetracarboxylic dianhydride and alicyclic tetracarboxylic dianhydride. Although it does not specifically limit as a tetracarboxylic acid dianhydride which gives such a structural unit, Aliphatic tetracarboxylic acid dianhydride, such as 1,2,3,4-butane tetracarboxylic acid dianhydride, is mentioned.

The structural unit arbitrarily contained in structural unit A may be 1 type, or 2 or more types may be sufficient as it.

Meanwhile, in the present specification, an aromatic tetracarboxylic dianhydride means a tetracarboxylic dianhydride containing one or more aromatic rings, and an alicyclic tetracarboxylic dianhydride includes one or more alicyclic rings and also an aromatic ring. means a tetracarboxylic dianhydride that does not contain, and the aliphatic tetracarboxylic dianhydride means a tetracarboxylic dianhydride that does not contain either an aromatic ring or an alicyclic ring.

(unit B)

Structural unit B is a structural unit derived from diamine and contains structural unit (B1) derived from the compound represented by formula (b1).

By including the structural unit (B1) in the structural unit B, heat resistance is excellent, and the effect of reducing yellowness is excellent, especially when combined with the compound (Y).

The proportion of the structural unit (B1) in the structural unit B is preferably 45 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, and particularly preferably 99 mol% or more. The upper limit of the ratio is not particularly limited, and is 100 mol% or less.

[Formula 11]

The structural unit (B1) preferably includes a structural unit (B11) derived from a compound represented by the following formula (b11), and the structural unit (B1) is more preferably represented by the following formula (b11) It is a structural unit (B11) derived from a compound.

[Formula 12]

The compound represented by formula (b11) is 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA).

By including structural unit (B11) in structural unit B, especially when combined with compound (Y), the effect of reducing yellowness is excellent.

The structural unit B may also contain structural units other than the structural unit (B1). The diamine giving such a structural unit is not particularly limited, but 4-aminophenyl-4-aminobenzoate (4-BAAB), 3,5-diaminobenzoic acid (3,5-DABA), 9,9- Bis (4-aminophenyl) fluorene, 1,4-phenylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene, 2,2'-dimethylbiphenyl-4,4'-diamine, 2, 2'-dimethylbiphenyl-4,4'-diamine, 4,4'-diaminodiphenylmethane, 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene, 2,2- Bis(4-aminophenyl)hexafluoropropane, 4,4'-diaminobenzanilide, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl-1H-indene- 5-Amine, α,α'-bis(4-aminophenyl)-1,4-diisopropylbenzene, N,N'-bis(4-aminophenyl)terephthalamide, 2,2-bis(3-amino -Aromatic diamines such as 4-hydroxyphenyl)hexafluoropropane 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.

Among these, it is preferably a compound represented by the following formula (b2), and the structural unit B preferably contains a structural unit (B2) derived from a compound represented by the formula (b2).

[Formula 13]

The compound represented by formula (b2) is 4-aminophenyl-4-aminobenzoate (4-BAAB).

Meanwhile, in the present specification, aromatic diamine means diamine containing one or more aromatic rings, and alicyclic diamine means diamine containing one or more alicyclic rings and not containing aromatic rings. Aliphatic diamine means diamine containing one or more alicyclic rings. It means diamine containing neither an aromatic ring nor an alicyclic ring.

The structural unit arbitrarily included in structural unit B may be one kind or two or more kinds.

(Method for producing polymer (X))

Polymer (X) may be produced by any method, but the following method is preferred.

As described above, in the polymer (X), any one of the repeating unit represented by the above general formula (1) (ie imide moiety) and the repeating unit represented by the above general formula (2) (ie amide acid moiety) Although one or both are included, these can be adjusted by changing the manufacturing method.

Specifically, in the production method in the case of including both the repeating unit represented by formula (1) and the repeating unit represented by formula (2) (method for producing an imide-amic acid copolymer), formula (1) ) By using only the process for producing a portion (polyimide portion) mainly containing the repeating unit represented by the formula (1), the polymer (X) (polyimide) substantially composed of the repeating unit represented by the formula (1) is obtained, Polymer (X) (polyamic acid) substantially composed of the repeating unit represented by formula (2) can be obtained by using only the process for producing the part mainly containing the repeating unit represented by (2) (polyamic acid part). You can get it.

Polymer (X) containing both the repeating unit represented by formula (1) and the repeating unit represented by formula (2) (hereinafter also referred to as an imide-amic acid copolymer) is the following steps 1 and 2 It is preferable to follow the method with

Step 1: Step of reacting the tetracarboxylic acid component constituting the imide moiety with the diamine component to obtain an imide oligomer

Step 2: Step of reacting the imide oligomer obtained in Step 1 with the tetracarboxylic acid component and diamine component constituting the amide acid moiety to obtain an imide-amic acid copolymer

On the other hand, in step 1, polymer (X) (polyimide) substantially composed of repeating units represented by formula (1) is obtained by reacting all the tetracarboxylic acid components and diamine components. Specifically, the method for producing Polymer (X) (polyimide) substantially composed of repeating units represented by Formula (1) includes the step 1 described above as “reacting the tetracarboxylic acid component constituting the polyimide with the diamine component. process to obtain polyimide”.

Further, by reacting all the tetracarboxylic acid components and diamine components in step 2 without performing step 1, polymer (X) (polyamic acid) substantially composed of repeating units represented by formula (2) is obtained. Specifically, the method for producing Polymer (X) (polyamic acid) substantially composed of repeating units represented by formula (2) includes the step 2 described above as “the tetracarboxylic acid component and the diamine component constituting the polyamic acid Reaction to obtain polyamic acid”.

[Process 1]

Step 1 is a step of obtaining an imide oligomer by reacting the tetracarboxylic acid component constituting the imide moiety with the diamine component.

As the tetracarboxylic acid component used in Step 1, it is preferable to include a compound that imparts the structural unit (A1), and it is preferable to use the entire amount in Step 1, and the compound to impart the structural unit (A1) Other tetracarboxylic acid components may be included. As the tetracarboxylic acid component other than the compound that imparts the structural unit (A1), a compound that imparts the structural unit (A2) or a compound that imparts the structural unit (A3) is preferable.

It is preferable that the diamine component used in step 1 contains the compound which provides structural unit (B1), and the diamine components other than the compound which provides structural unit (B1) are within the range which does not impair the effect of this invention. may contain As the tetracarboxylic acid component other than the compound imparting the structural unit (B1), a compound imparting the structural unit (B2) is preferable.

In Step 1, the diamine component relative to the tetracarboxylic acid component is preferably 1.01 to 2 moles, more preferably 1.05 to 1.9 moles, still more preferably 1.1 to 1.7 moles.

On the other hand, when obtaining polymer (X) (polyimide) which consists of the repeating unit substantially represented by Formula (1), it is preferable that the diamine component with respect to a tetracarboxylic acid component is 0.9-1.1 mol.

There is no particular restriction on the method of reacting the tetracarboxylic acid component and the diamine component to obtain the imide oligomer in Step 1, and a known method can be used.

As a specific reaction method, (1) a method of introducing a tetracarboxylic acid component, a diamine component, and a reaction solvent into a reactor, stirring at 10 to 110 ° C. for 0.5 to 30 hours, and then raising the temperature to perform an imidation reaction, ( 2) After dissolving the diamine component and the reaction solvent in a reactor, the tetracarboxylic acid component is added, stirred at 10 to 110 ° C. for 0.5 to 30 hours as necessary, and then the temperature is raised to perform an imidation reaction; (3) A method of introducing a tetracarboxylic acid component, a diamine component, and a reaction solvent into a reactor, immediately raising the temperature to perform an imidation reaction, and the like.

In the imidation reaction, it is preferable to carry out 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 rate can be further increased.

In the said imidation reaction, a well-known imidation catalyst can be used. A base catalyst or an acid catalyst is mentioned as an imidation catalyst.

As the base catalyst, pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethylamine, tripropylamine, tributylamine , organic base catalysts such as triethylenediamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline, inorganic bases such as potassium hydroxide, sodium hydroxide, potassium carbonate, sodium carbonate, potassium hydrogencarbonate, and sodium hydrogencarbonate A catalyst can be mentioned.

Examples of the acid catalyst include crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methyl benzoic acid, oxybenzoic acid, terephthalic acid, benzenesulfonic acid, p-toluenesulfonic acid, and naphthalenesulfonic acid. The said imidation catalyst can also be used individually or in combination of 2 or more types.

Among the above, from the viewpoint of handleability, base catalysts are preferred, organic base catalysts are more preferred, at least one selected from triethylamine and triethylenediamine is still more preferred, and triethylamine is still more preferred.

The temperature of the imidation reaction is preferably 120 to 250°C, more preferably 160 to 200°C, from the viewpoint of 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 distillation of generated water.

The imide oligomer obtained in step 1 preferably has an imide repeating structural unit formed from a compound providing the structural unit (A1) and a compound providing the structural unit (B1).

By the above method, a solution containing an imide oligomer dissolved in a solvent is obtained. The solution containing the imide oligomer obtained in Step 1 may contain at least a part of the components used as the tetracarboxylic acid component or the diamine component in Step 1 as unreacted monomers within a range not impairing the effects of the present invention. there is.

[Process 2]

Step 2 in the production method of the present invention is a step for obtaining an imide-amic acid copolymer by reacting the imide oligomer obtained in step 1 with the tetracarboxylic acid component and diamine component constituting the amide acid moiety.

As the tetracarboxylic acid component used in step 2, it is preferable to include a compound that imparts structural unit (A1), and it is preferable to use the entire amount in step 1, and the compound to impart structural unit (A1) Other tetracarboxylic acid components may be included. As the tetracarboxylic acid component other than the compound that imparts the structural unit (A1), a compound that imparts the structural unit (A2) or a compound that imparts the structural unit (A3) is preferable.

It is preferable that the diamine component used in step 2 contains the compound which provides structural unit (B1), and diamine components other than the compound which provides structural unit (B1) within the range which does not impair the effect of this invention. may contain As the tetracarboxylic acid component other than the compound imparting the structural unit (B1), a compound imparting the structural unit (B2) is preferable.

On the other hand, when polymer (X) (polyamic acid) substantially composed of repeating units represented by formula (2) is obtained by performing only step 2, the diamine component relative to the tetracarboxylic acid component is set to 0.9 to 1.1 mol. it is desirable

There is no particular restriction on the method of reacting the tetracarboxylic acid component and the diamine component and the imide oligomer obtained in step 1 in step 2, and a known method can be used.

As a specific reaction method, (1) the imide oligomer, tetracarboxylic acid component, diamine component and solvent obtained in step 1 are introduced into a reactor, and the temperature is 0 to 120 ° C., preferably 5 to 80 ° C. Time-stirring method, (2) After putting the imide oligomer and the solvent obtained in step 1 into the reactor to dissolve them, the tetracarboxylic acid component and the diamine component are added, and the temperature is 0 to 120°C, preferably 5 to 80°C. The method of stirring for 1 to 72 hours in the range, etc. are mentioned.

In the case of reacting at 80°C or lower, the molecular weight of the copolymer obtained in step 2 does not fluctuate depending on the temperature history during polymerization, and the progress of thermal imidation can be suppressed, so that the copolymer is stable. can be manufactured with

By the above method, a copolymer solution containing an imide-amic acid copolymer dissolved in a solvent is obtained. Further, by performing only step 1, a polyimide solution containing polyimide is obtained, and by performing only step 2, a polyamic acid solution containing polyamic acid is obtained.

The concentration of the copolymer in the obtained solution is usually 1 to 50% by mass, preferably 3 to 35% by mass, and more preferably 5 to 30% by mass.

In addition, the concentration of the polyimide in the obtained solution is usually 1 to 50% by mass, preferably 3 to 35% by mass, and more preferably 5 to 30% by mass.

Furthermore, the concentration of the polyamic acid in the obtained solution is usually 1 to 50% by mass, preferably 3 to 35% by mass, and more preferably 5 to 30% by mass.

The number average molecular weight of the imide-amic acid copolymer obtained by the above production method is preferably 5,000 to 500,000 from the viewpoint of mechanical strength of the polyimide film obtained. From the same viewpoint, the weight average molecular weight (Mw) is preferably 10,000 to 800,000, more preferably 100,000 to 300,000. On the other hand, the number average molecular weight and weight average molecular weight of the copolymer can be obtained from, for example, standard polymethyl methacrylate (PMMA) conversion values measured by gel filtration chromatography.

The number average molecular weight of the polyimide obtained by the above production method is preferably 5,000 to 500,000 from the viewpoint of mechanical strength of the polyimide film obtained. From the same viewpoint, the weight average molecular weight (Mw) is preferably 10,000 to 800,000, more preferably 100,000 to 300,000.

The number average molecular weight of the polyamic acid obtained by the above production method is preferably 5,000 to 500,000 from the viewpoint of mechanical strength of the polyimide film obtained. From the same viewpoint, the weight average molecular weight (Mw) is preferably 10,000 to 800,000, more preferably 100,000 to 300,000.

Next, the raw materials used in this production method will be described.

[Tetracarboxylic acid component]

Examples of the compound giving the structural unit (A1) as the tetracarboxylic acid component used as a raw material in the present production method include compounds represented by formula (a1), but are not limited thereto, and the same structural unit It may be a derivative thereof to the extent that it gives Examples of the derivative include tetracarboxylic acid corresponding to the compound represented by formula (a1) and alkyl esters of the tetracarboxylic acid. As a compound which gives structural unit (A1), the compound represented by formula (a1) is preferable.

Similarly, as the compound giving the structural unit (A2), the compound represented by formula (a2) can be mentioned, but it is not limited thereto, and a derivative thereof may be used within the range giving the same structural unit. Examples of the derivative include tetracarboxylic acid corresponding to the compound represented by formula (a2) and alkyl esters of the tetracarboxylic acid. As a compound which gives structural unit (A2), the compound represented by formula (a2) is preferable.

Furthermore, as a compound giving structural unit (A3), although the compound represented by formula (a3) can be mentioned, it is not limited to it, A derivative thereof may also be sufficient as the range giving the same structural unit. Examples of the derivative include tetracarboxylic acid corresponding to the compound represented by formula (a3) and alkyl esters of the tetracarboxylic acid. As a compound which gives structural unit (A3), the compound represented by formula (a3) is preferable.

[diamine component]

As the diamine component used as a raw material in this production method, the compound giving the structural unit (B1) includes diamine, but is not limited thereto, and may be a derivative thereof within the scope of giving the same structural unit. there is. Examples of the derivative include diisocyanates corresponding to diamines. As a compound which gives structural unit (B1), diamine is preferable.

Similarly, examples of the compound imparting the structural unit (B2) include diamine, but are not limited thereto, and may be derivatives thereof within the scope of imparting the same structural unit. Examples of the derivative include diisocyanates corresponding to diamines. As a compound which provides structural unit (B2), diamine is preferable.

In the present invention, the ratio of the amount of the tetracarboxylic acid component and the diamine component used in the entire process of copolymer production including step 1 and step 2 is preferably 0.9 to 1.1 mole of the diamine component per 1 mole of the tetracarboxylic acid component. do.

[Encapsulation agent]

In addition to the tetracarboxylic acid component and the diamine component described above, an end capping agent can also be used for the production of Polymer (X). When performing both steps 1 and 2, it is preferable to use the terminal capping agent at the time of step 2.

As the end capping agent, monoamines or dicarboxylic acids are preferable. The amount of the end capping agent to be introduced is preferably 0.0001 to 0.1 mol, particularly preferably 0.001 to 0.06 mol, per 1 mol of the tetracarboxylic acid component. Examples of the monoamine endcapping agent include methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine , 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, etc. are recommended. Among these, benzylamine and aniline can be used conveniently. As the dicarboxylic acid endcapping agent, dicarboxylic acids are preferable, and some of them may be ring-closed. 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 used conveniently.

〔solvent〕

The solvent used in the method for producing Polymer (X) may be any solvent capable of dissolving the resulting imide-amic acid copolymer. Examples thereof include aprotic solvents, phenolic solvents, ether solvents, and carbonate solvents.

Specific examples of the aprotic solvent include N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, 1,3-dimethylimidazoli Amide-based solvents such as dinon and tetramethylurea, lactone-based solvents such as γ-butyrolactone and γ-valerolactone, phosphorus-containing amide-based solvents such as hexamethylphosphoricamide and hexamethylphosphinetriamide, and dimethylsulfone. , Sulfur-containing solvents such as dimethyl sulfoxide and sulfolane, ketone solvents such as acetone, methyl ethyl ketone, cyclohexanone and methylcyclohexanone, and ester solvents such as acetic acid (2-methoxy-1-methylethyl) etc. can be 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 solvent include 1,2-dimethoxyethane, bis(2-methoxyethyl) ether, 1,2-bis(2-methoxyethoxy)ethane, bis[2-(2-methoxyethyl) ether, oxyethoxy) ethyl] ether, tetrahydrofuran, 1,4-dioxane, and the like.

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 preferred, amide-based solvents are more preferred, and N-methyl-2-pyrrolidone is still more preferred. These reaction solvents may be used alone or in combination of two or more.

<Compound (Y)>

Compound (Y) contained in the polymer composition of the present invention is represented by the following general formula (3).

[Formula 14]

(In formula (3), R ³ is selected from the group consisting of an alkyl group having 1 to 30 carbon atoms, a phenyl group, an alkoxy group, an acryloyl group, a methacryloyl group, an acryloyloxyethyl group, and a methacryloyloxyethyl group is at least one, and n is 0 to 2.)

By including the compound (Y), a film having heat resistance and low yellowness can be obtained, and furthermore, the transparency of the film can be improved.

In formula (3), R ³ is selected from the group consisting of an alkyl group having 1 to 30 carbon atoms, a phenyl group, an alkoxy group, an acryloyl group, a methacryloyl group, an acryloyloxyethyl group, and a methacryloyloxyethyl group. is at least one, preferably an alkyl group having 1 to 30 carbon atoms.

A plurality of R ³ may be the same or different, but are preferably the same.

n is 0-2, Preferably it is 1-2.

Compound (Y) is a phosphorus compound, and specific examples of compound (Y) include at least one selected from the group consisting of acidic phosphoric acid esters and phosphoric acid, preferably acidic phosphoric acid esters.

Examples of the acidic phosphoric acid ester include isotridecyl acid phosphate, dibutyl phosphate and the like, and isotridecyl acid phosphate is preferable.

The content of the compound (Y) is preferably 10 ppm or more and 10,000 ppm or less, more preferably 100 ppm or more and 5,000 ppm or less, and still more preferably 500 ppm or more and 2,000 ppm or less, relative to the polymer (X). When the amount of the compound (Y) is within this range, a film having heat resistance and low yellowness can be obtained, and furthermore, the transparency of the film can be improved. In the present specification, "ppm" represents parts per million by mass.

[Varnish]

The varnish of the present invention is obtained by dissolving the polymer composition described above in an organic solvent. That is, the varnish of the present invention is formed by dissolving Polymer (X) and Compound (Y) in an organic solvent, and the varnish of the present invention contains Polymer (X), Compound (Y) and an organic solvent, and the polymer ( X) and compound (Y) are dissolved in the organic solvent.

The organic solvent is not particularly limited as long as it dissolves the polymer (X) and the compound (Y), but it is preferable to use the above-mentioned compounds alone or in a mixture of two or more as the solvent used for the production of the polymer (X). desirable.

The varnish of the present invention may be obtained by mixing and dissolving the compound (Y) in the polymer (X) solution described above, or may be obtained by adding a diluting solvent.

When the polymer (X) contained in the varnish of the present invention contains the repeating unit (amic acid moiety) represented by formula (2), from the viewpoint of efficiently advancing imidation of the amic acid moiety, further imidation A catalyst and a dehydration catalyst may be contained. The imidation catalyst may be an imidation catalyst having a boiling point of 40°C or more and 180°C or less, and an amine compound having a boiling point of 180°C or less is mentioned as a preferable one. If the imidation catalyst has a boiling point of 180°C or less, there is no fear that the film is colored and the appearance is deteriorated during drying at a high temperature after film formation. Moreover, if it is an imidation catalyst whose boiling point is 40 degreeC or more, possibility of volatilization before imidation fully advances can be avoided.

Pyridine or picoline is mentioned as an amine compound suitably used as an imidation catalyst. The said imidation catalyst can also be used individually or in combination of 2 or more types.

Examples of the dehydration catalyst include acid anhydrides such as acetic anhydride, propionic anhydride, n-butyric anhydride, benzoic anhydride, and trifluoroacetic anhydride; carbodiimide compounds such as dicyclohexylcarbodiimide; etc. can be mentioned. You may use these individually or in combination of 2 or more types.

Since the polymer (X) contained in the varnish of the present invention has solvent solubility, a high-concentration varnish can be obtained. The varnish of the present invention preferably contains 3 to 40% by mass of Polymer (X), more preferably 5 to 40% by mass, and still more preferably 10 to 30% by mass. The viscosity of the varnish is preferably 0.1 to 100 Pa·s, and more preferably 0.1 to 20 Pa·s. The viscosity of the varnish is a value measured at 25°C using an E-type viscometer.

In addition, the varnish of the present invention contains an inorganic filler, an adhesion promoter, a release agent, a flame retardant, a UV stabilizer, a surfactant, a leveling agent, an antifoaming agent, an optical whitening agent, a crosslinking agent, and a polymerization initiator within a range that does not impair the required characteristics of the polyimide film. , various additives such as a photosensitizer may be included.

The manufacturing method of the varnish of this invention is not specifically limited, A well-known method can be applied.

[Polyimide film and manufacturing method of polyimide film]

The polyimide film of the present invention is a polyimide resin formed by imidizing the amide acid moiety of the polymer (X) when the repeating unit (amic acid moiety) represented by the formula (2) is included in the polymer (X), and Compound (Y) is included. Moreover, when polymer (X) is a polyimide, the said polyimide or the polyimide resin whose molecular weight was further adjusted by heating, and compound (Y) are included. Therefore, the polyimide film of the present invention has excellent heat resistance and low yellowness.

The polyimide film of the present invention can be produced using the varnish described above.

There is no particular restriction on the method for producing a polyimide film using the varnish of the present invention, but the following method is preferred.

That is, a method of applying the above-described varnish on a support and then heating is preferable. method is preferred.

As the polyimide film of the present invention, a polyimide film obtained by applying the above-mentioned varnish on a support and heating is preferable. Specifically, the polymer (X) and the compound (Y) are mixed in an organic solvent. A polyimide film obtained by applying a dissolved varnish on a support and heating it is preferred.

As a support body, a smooth glass plate, a metal plate, plastic etc. are mentioned, for example.

After the varnish is applied on a support or formed into a film, organic solvents such as reaction solvents and diluting solvents contained in the varnish are removed by heating to obtain a polymer film, and the polymer contained in the polymer film contains amide When there is an acid moiety, a polyimide film can be manufactured by imidating it by heating (dehydration ring closure) and then peeling it from the support.

The weight average molecular weight (Mw) of the polyimide resin contained in the polyimide film of the present invention is preferably 10,000 to 800,000, more preferably 30,000 to 500,000, and still more preferably from the viewpoint of mechanical strength of the film. 50,000 to 400,000, more preferably 100,000 to 300,000. On the other hand, the weight average molecular weight of the copolymer can be obtained, for example, from a standard polymethyl methacrylate (PMMA) conversion value measured by gel filtration chromatography.

The heating temperature when drying the varnish of the present invention to obtain a polymer film is preferably 50 to 150°C. The heating temperature for imidizing the polymer by heating is preferably 200 to 500°C, more preferably 250 to 450°C, still more preferably 300 to 400°C. The heating time is usually 1 minute to 6 hours, preferably 5 minutes to 2 hours, and more preferably 15 minutes to 1 hour.

The heating atmosphere includes air gas, nitrogen gas, oxygen gas, hydrogen gas, nitrogen/hydrogen mixed gas, and the like. In order to suppress coloring of the obtained polyimide resin, nitrogen gas having an oxygen concentration of 100 ppm or less and a hydrogen concentration of 0.5 % or less of nitrogen/hydrogen mixed gas is preferred.

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

The thickness of the polyimide film of the present invention can be appropriately selected depending on the application and the like, but is preferably 1 to 250 μm, more preferably 5 to 100 μm, still more preferably 5 to 50 μm. When 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 and viscosity of the varnish.

By using the polymer composition of the present invention, a polyimide film having excellent heat resistance and low yellowness can be obtained, and the resulting polyimide film of the present invention has excellent heat resistance and low yellowness. 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 89% or more, when the film has a thickness of 10 μm.

The yellow index (YI) is preferably 12 or less, more preferably 11 or less, and from the viewpoint of excellent colorlessness, when a film having a thickness of 10 μm is preferably 9 or less, more preferably 8 or less. .

The 1% weight loss temperature is preferably 430°C or higher, more preferably 480°C or higher, even more preferably 500°C or higher, and still more preferably 510°C or higher. Here, the 1% weight loss temperature is the temperature when the polyimide film is heated to 40 to 550 ° C. at a heating rate of 10 ° C./min, and the weight is reduced by 1% compared to the weight at 300 ° C.

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

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 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 examples. However, the present invention is not limited at all by these examples.

Each physical property of the film obtained in Examples and Comparative Examples was measured by the method shown below.

(1) Film thickness

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

On the other hand, the film thicknesses of Example 5 and Comparative Example 6 were measured using a film thickness meter Filmetrics F20 (manufactured by Filmetrics Co., Ltd.).

(2) Total light transmittance, yellow index (YI)

The total light transmittance was based on JIS K7105: 1981, and YI was measured based on ASTM D1925 (C light source, 2°) using a simultaneous color and turbidity measuring instrument "COH7700" manufactured by Nippon Denshoku Kogyo Co., Ltd.

(3) 1% weight reduction temperature (Td 1%)

Differential thermal thermogravimetric simultaneous measuring device "NEXTA STA200RV" manufactured by Hitachi High-Tech Sciences Co., Ltd. was used. The temperature of the sample was raised to 40 to 150 °C at a heating rate of 10 °C/min, maintained at 150 °C for 30 minutes to remove moisture, and then heated to 550 °C. Compared to the weight after holding at 150 ° C. for 30 minutes, the temperature when the weight decreased by 1% was set as the 1% weight loss temperature. The weight loss temperature is excellent as the number increases.

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

<Tetracarboxylic acid component>

CpODA: norbonane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride (formula (a1) compound shown)

s-BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride (manufactured by Mitsubishi Chemical Corporation, compound represented by formula (a2s))

BPAF: 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride (manufactured by JFE Chemical Co., Ltd.; compound represented by formula (a3))

<Diamine component>

6FODA: 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (compound represented by formula (b11))

4-BAAB: 4-aminophenyl-4-aminobenzoate (manufactured by Nippon Sunryang Chemical Co., Ltd.; compound represented by formula (b2))

<Phosphorus compound>

JP-513: isotridecyl acid phosphate (manufactured by Johoku Chemical Industry Co., Ltd., a compound in formula (3) wherein R ³ is an isotridecyl group and n is 1, and a compound in which R ³ is an isotridecyl group and n 1:1 mixture of these two compounds)

DBP: Dibutyl phosphate (manufactured by Johoku Chemical Industry Co., Ltd., in formula (3), R ³ is a butyl group, and n is a compound of 2)

Phosphoric acid: the compound in formula (3), wherein n is 0

Trimethyl phosphate: In formula (3), R ³ is a methyl group, and n is 3.

Triphenylphosphine: In the formula (3), R ³ is a phenyl group, and n is a compound of 3

<Other compounds>

Irganox 1010 (antioxidant): pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (manufactured by BASF Japan Co., Ltd.)

<Surface conditioner>

BYK-378: Silicone surface conditioner (manufactured by Big Chemie Japan Co., Ltd.)

The symbols of solvents and catalysts used in Examples and Comparative Examples are as follows.

NMP: N-methyl-2-pyrrolidone (manufactured by Tokyo Pure Chemical Industries, Ltd.)

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

<Example 1>

26.899 g (0.0800 mol) of 6FODA and 94.146 g of NMP were added to a 500 mL 5-neck round bottom flask equipped with a stainless steel half-moon-shaped stirring blade, a nitrogen inlet tube, a Dean Stark equipped with a cooling tube, a thermometer, and a glass end cap. The mixture was added and stirred at a rotation speed of 200 rpm under a nitrogen atmosphere at a system temperature of 50° C. to obtain a solution.

To this solution, 23.536 g (0.0800 mol) of s-BPDA and 23.536 g of NMP were added at once, and the mixture was stirred for 5 hours while maintaining at 50° C. with a mantle heater.

After that, 84.059 g of NMP was added and homogenized, and then it was returned to room temperature to obtain a polyamic acid varnish having a solid content concentration of 20% by mass.

0.02 g (1000 ppm based on polyamic acid) and 0.02 g (1000 ppm based on polyamic acid) of JP-513 and 0.02 g (1000 ppm based on polyamic acid) of JP-513 were added to 100 g of the obtained varnish and stirred for 30 minutes to homogenize to obtain a polyamic acid composition varnish.

Subsequently, the obtained polyamic acid composition varnish was applied on a glass plate by spin coating, maintained at 80° C. for 20 minutes on a hot plate, and then transferred to a hot air dryer and heated to 420° C./min under a nitrogen atmosphere at a heating rate of 5° C./min. The temperature was raised to °C, heated at 420 °C for 60 minutes in a hot air dryer under a nitrogen atmosphere, the solvent was evaporated and imidized to obtain a polyimide film. The results are shown in Table 1.

<Examples 2 and 3 and Comparative Examples 2 to 4>

In the same manner as in Example 1, except that 0.02 g (1000 ppm based on polyamic acid) of each phosphorus compound or other compound shown in Table 1 was used instead of 0.02 g (1000 ppm based on polyamic acid) of JP-513. , to obtain a polyimide film. The results are shown in Table 1.

<Comparative Example 1>

A polyimide film was obtained in the same manner as in Example 1 except that JP-513 was not used. The results are shown in Table 1.

<Example 4>

Instead of 23.536 g (0.0800 mole) of s-BPDA, 0.0800 mole of CpODA was used, the holding temperature after the raw materials were added at once was set to 10 ° C, and stirred for 5 hours. By the same method as in Example 1, A polyamic acid composition varnish was obtained.

Subsequently, the obtained polyamic acid composition varnish was applied on a glass plate by spin coating, maintained at 80° C. for 20 minutes on a hot plate, and then transferred to a hot air dryer and heated to 420° C./min under a nitrogen atmosphere at a heating rate of 5° C./min. The temperature was raised to °C, heated at 420 °C for 60 minutes in a hot air dryer under a nitrogen atmosphere, the solvent was evaporated and imidized to obtain a polyimide film. The results are shown in Table 1.

<Comparative Example 5>

A polyimide film was obtained in the same manner as in Example 4 except that JP-513 was not used. The results are shown in Table 1.

<Example 5>

10.087 g (0.030 mol) of 6FODA and 47.017 g of NMP were added to a 500 mL 5-necked round bottom flask equipped with a stainless steel half-moon-shaped stirring blade, a nitrogen inlet pipe, a Dean Stark equipped with a cooling pipe, a thermometer, and a glass end cap. and stirred at a rotation speed of 200 rpm under a nitrogen atmosphere at a system temperature of 70° C. to obtain a solution.

To this solution, 9.169 g (0.020 mol) of BPAF and 11.754 g of NMP were added at once, and then 0.101 g of TEA was added as an imidization catalyst, heated with a mantle heater, and the temperature in the reaction system was raised to 190 °C for about 20 minutes. raised to °C. Components distilled off were collected, and while adjusting the number of rotations according to the increase in viscosity, the temperature inside the reaction system was maintained at 190°C and refluxed for 1 hour. Thereafter, 147.043 g of NMP was added, and the temperature in the reaction system was cooled to 50° C. to obtain a solution containing an oligomer having an imide repeating structural unit.

To the obtained solution, 23.538 g (0.080 mol) of s-BPDA, 15.978 g (0.070 mol) of 4-BAAB, and 26.386 g of NMP were added all at once, and the mixture was stirred at 50°C for 5 hours. Thereafter, NMP was added and homogenized so that the solid content concentration was about 15% by mass, thereby obtaining a varnish containing a copolymer having an imide repeating structural unit and an amide acid structural unit (imide-amic acid copolymer varnish).

To 100 g of the obtained varnish, 0.015 g of JP-513 (1000 ppm based on imide-amic acid copolymer) and 0.015 g of BYK-378 (1000 ppm based on imide-amic acid copolymer) were added and stirred for 30 minutes to homogenize, An imide-amic acid copolymer composition varnish was obtained.

Subsequently, the obtained imide-amic acid copolymer composition varnish was applied on a glass plate by spin coating, held on a hot plate at 80°C for 20 minutes, and then transferred to a hot air dryer at a heating rate of 5°C under a nitrogen atmosphere. The temperature was raised to 430°C at /min, and the solvent was evaporated by heating at 430°C for 60 minutes in a hot air dryer under a nitrogen atmosphere, followed by thermal imidization to obtain a polyimide film. The results are shown in Table 1.

<Comparative Example 6>

A polyimide film was obtained in the same manner as in Example 5, except that JP-513 was not used. The results are shown in Table 1.

On the other hand, since the polyimide film obtained in Comparative Example 6 could not be peeled from the glass plate, the total light transmittance and yellow index (YI) of Example 5 and Comparative Example 6 were measured including the glass plate. In addition, for the polyimide film obtained in Comparative Example 6, the 1% weight loss temperature (Td 1%) was not measured.

[Table 1]

As shown in Table 1, it can be seen that the polyimide film obtained from the polymer composition of the present invention has excellent heat resistance and low yellowness. The polyimide film obtained from the polymer composition of the present invention is also excellent in transparency.

Claims (7)

Polymer (X) containing at least one selected from the group consisting of a repeating unit represented by the following general formula (1) and a repeating unit represented by the following general formula (2);
A polymer composition containing a compound (Y) represented by the following general formula (3).
[Formula 1]

(In Formula (1), X ¹ is a tetravalent group having an alicyclic structure or an aromatic ring.
In Formula (2), X ² is a tetravalent group having an alicyclic structure or an aromatic ring, and R ¹ and R ² are each independently hydrogen, an alkyl group having 1 to 6 carbon atoms, or an alkylsilyl group having 3 to 9 carbon atoms.
In formula (3), R ³ is selected from the group consisting of an alkyl group having 1 to 30 carbon atoms, a phenyl group, an alkoxy group, an acryloyl group, a methacryloyl group, an acryloyloxyethyl group, and a methacryloyloxyethyl group. At least one, and n is 0 to 2.) According to claim 1,
The polymer composition in which the repeating unit represented by the said formula (1) is 10 mol% or more with respect to all the repeating units of the said polymer (X). According to claim 1 or 2,
The polymer composition in which the repeating unit represented by the said Formula (2) is 10 mol% or more with respect to all the repeating units of the said polymer (X). According to any one of claims 1 to 3,
The polymer composition whose content of compound (Y) is 10 ppm or more and 10,000 ppm or less with respect to polymer (X). A varnish obtained by dissolving the polymer composition according to any one of claims 1 to 4 in an organic solvent. A polyimide film obtained by applying the varnish according to claim 5 on a support and heating it. A method for producing a polyimide film comprising applying the varnish according to claim 5 onto a support and heating the varnish.