TW202214747A - Polyimide resin, polyimide varnish, and polyimide film - Google Patents

Abstract

A polyimide resin containing structural units A derived from a tetracarboxylic dianhydride and structural units B derived from a diamine, wherein the structural units A include a structural unit (A1) derived from 9,9-bis (3,4-dicarboxyphenyl) fluorene acid dianhydride and a structural unit (A2) derived from an aliphatic tetracarboxylic dianhydride, and the structural units B include a structural unit (B1) derived from 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane.

Description

Polyimide resin, polyimide varnish and polyimide film

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

Polyimide resins can be obtained from aromatic tetracarboxylic anhydrides and aromatic diamines. Generally speaking, they have excellent heat resistance, chemical resistance, mechanical properties, electrical properties due to molecular rigidity, resonance stabilization, and strong chemical bonding. Therefore, it is widely used in forming materials, composite materials, electrical and electronic parts, optical materials, displays, aerospace and other fields. In particular, the application of polyimide resins to flexible devices is also being considered by effectively utilizing the fact that polyimide resins are softer than glass materials conventionally used in applications such as electrical and electronic parts, optical materials, and displays.

For example, Patent Document 1 discloses a composition for forming a flexible device substrate containing a polyimide, an organic The solvent, the polyimide, is a reaction product of a tetracarboxylic dianhydride component containing an alicyclic tetracarboxylic dianhydride and a diamine component containing a fluorine-containing aromatic diamine. [Prior Art Literature] [Patent Literature]

[Patent Document 1] International Publication No. 2018/097143

[The problem to be solved by the invention]

In recent years, in particular, the use of polyimide resins for displays or to protect the previous panel has progressed. Considering the replacement of glass materials used in the past, it has become necessary to have good mechanical strength, that is, high strength, high Elastic modulus of polyimide resin. However, conventional high-strength polyimide resins have many problems such as insufficient flexibility and poor colorless transparency. Recently, in order to also be used as a display and a protective plate of a smartphone with a foldable structure, high strength is required, and higher flexibility is also required, and the property of the polyimide film to recover its shape after deformation has also become necessary. . Therefore, a polyimide resin having these properties is desired. That is, the problem to be solved by the present invention is to provide a polyimide resin which can form a film having both mechanical properties and colorless transparency, high strength, and excellent deformation recovery properties, and a polyimide resin having both Mechanical properties and colorless transparency, high strength, and excellent deformation recovery of polyimide film. [Means of Solving Problems]

As a result of intensive research, the inventors of the present invention found that a polyimide resin including a combination of specific structural units can solve the above-mentioned problems, and completed the present invention.

[2]如上述[1]之聚醯亞胺樹脂，其中，該構成單元(A2)係來自脂環族四羧酸二酐之構成單元。 [3]如上述[1]或[2]之聚醯亞胺樹脂，其中，該構成單元(A2)係選自於由來自下式(a2-1)表示之化合物之構成單元(A2-1)、來自下式(a2-2)表示之化合物之構成單元(A2-2)、及來自下式(a2-3)表示之化合物之構成單元(A2-3)構成之群組中之至少一者。 [化2]

[4]如上述[1]~[3]中任一項之聚醯亞胺樹脂，其中，該構成單元(B1)相對於該構成單元B之比例為30莫耳%以上。 [5]如上述[1]~[4]中任一項之聚醯亞胺樹脂，其中，該構成單元(A1)相對於該構成單元A之比例為50~90莫耳%。 [6]如上述[1]~[5]中任一項之聚醯亞胺樹脂，其中，該構成單元(A2)係來自下式(a2-2)表示之化合物之構成單元(A2-2)。 [化3]

[7]一種聚醯亞胺清漆，係將如上述[1]~[6]中任一項之聚醯亞胺樹脂溶解於有機溶劑而成。 [8]一種聚醯亞胺薄膜，係含有如上述[1]~[6]中任一項之聚醯亞胺樹脂。 [發明之效果] That is, the present invention relates to the following [1] to [8]. [1] A polyimide resin having a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine, the structural unit A including a structural unit derived from a compound represented by the following formula (a1) ( A1), and the structural unit (A2) derived from aliphatic tetracarboxylic dianhydride, this structural unit B contains the structural unit (B1) derived from the compound represented by following formula (b1). [hua 1]

[2] The polyimide resin according to the above [1], wherein the structural unit (A2) is a structural unit derived from an alicyclic tetracarboxylic dianhydride. [3] The polyimide resin according to the above [1] or [2], wherein the structural unit (A2) is selected from the structural unit (A2-1) derived from the compound represented by the following formula (a2-1). ), a structural unit (A2-2) derived from a compound represented by the following formula (a2-2), and at least one of the group consisting of a structural unit (A2-3) derived from a compound represented by the following formula (a2-3) By. [hua 2]

[4] The polyimide resin according to any one of the above [1] to [3], wherein the ratio of the structural unit (B1) to the structural unit B is 30 mol % or more. [5] The polyimide resin according to any one of the above [1] to [4], wherein the ratio of the structural unit (A1) to the structural unit A is 50 to 90 mol %. [6] The polyimide resin according to any one of the above [1] to [5], wherein the structural unit (A2) is a structural unit (A2-2) derived from a compound represented by the following formula (a2-2). ). [hua 3]

[7] A polyimide varnish prepared by dissolving the polyimide resin according to any one of the above [1] to [6] in an organic solvent. [8] A polyimide film comprising the polyimide resin according to any one of the above [1] to [6]. [Effect of invention]

According to the present invention, a polyimide resin capable of forming a film having both mechanical properties and colorless transparency, high strength and excellent deformation recovery properties, and a polyimide containing the polyimide resin can be provided Varnishes, and polyimide films that have both mechanical properties and colorless transparency, have high strength, and are also excellent in recovery from deformation.

以下，針對本發明之聚醯亞胺樹脂進行說明。 [Polyimide Resin] The polyimide resin of the present invention has a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from a diamine, and the structural unit A includes a structure derived from the following formula (a1) The structural unit (A1) of the compound and the structural unit (A2) derived from the aliphatic tetracarboxylic dianhydride, and the structural unit B includes the structural unit (B1) derived from the compound represented by the following formula (b1). [hua 4]

Hereinafter, the polyimide resin of the present invention will be described.

[Constituent Unit A] The structural unit A contained in the polyimide of the present invention is a structural unit derived from tetracarboxylic dianhydride occupied in the polyimide resin. The structural unit A includes the structural unit (A1) derived from the compound represented by the above formula (a1) and the structural unit (A2) derived from the aliphatic tetracarboxylic dianhydride.

The compound represented by the above formula (a1) is 9,9-bis(3,4-dicarboxyphenyl)fornic acid dianhydride (BPAF). When the structural unit A includes the structural unit (A1), the mechanical strength of the obtained polyimide resin is improved.

The structural unit (A2) is a structural unit derived from an aliphatic tetracarboxylic dianhydride, and the structural unit (A2) preferably contains a structural unit derived from an alicyclic tetracarboxylic dianhydride, and more preferably contains a structural unit derived from a compound having 4 to 25 carbon atoms. The structural unit of alicyclic tetracarboxylic dianhydride. By including the structural unit derived from the tetracarboxylic dianhydride which has an alicyclic ring, deformation recovery property and colorless transparency become favorable, maintaining mechanical strength. In addition, in this specification, the aliphatic tetracarboxylic dianhydride refers to a tetracarboxylic dianhydride that does not contain an aromatic ring, and the alicyclic tetracarboxylic dianhydride refers to aliphatic tetracarboxylic dianhydride that contains one or more lipids. Cyclic tetracarboxylic dianhydride. The "alicyclic" herein refers to a structure in which carbon atoms are bonded to a ring, excluding the cyclic hydrocarbon structure of the aromatic ring, and the number of carbons in the alicyclic refers to the number of carbons constituting the ring.

Specific examples of alicyclic tetracarboxylic dianhydride include 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 1,2,3,4-cyclobutanetetracarboxylic dianhydride , norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride, bicyclo[2.2. 2] Oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyltetracarboxylic dianhydride, their positional isomers, and the like. As a specific example of aliphatic tetracarboxylic dianhydride other than alicyclic tetracarboxylic dianhydride, 1, 2, 3, 4- butane tetracarboxylic dianhydride etc. are mentioned.

上述式(a2-1)表示之化合物係1,2,3,4-環丁烷四羧酸二酐(CBDA)。 上述式(a2-2)表示之化合物係1,2,4,5-環己烷四羧酸二酐(HPMDA)。 上述式(a2-3)表示之化合物係降莰烷-2-螺-α-環戊酮-α’-螺-2’’-降莰烷-5,5’’,6,6’’-四羧酸二酐(CpODA)。 藉由構成單元A包含構成單元(A2)，在維持機械強度的同時，變形回復性、無色透明性變得良好。 如上述方式，藉由來自四羧酸二酐之構成單元A具有構成單元(A1)及(A2)，本發明之聚醯亞胺樹脂及聚醯亞胺薄膜在兼具機械物性及無色透明性，為高強度的同時，變形回復性亦優良的理由雖尚未確定，據認為係來自茀基之剛性及脂肪族化合物之自由度。 Among these, the structural unit (A2) derived from the aliphatic tetracarboxylic dianhydride preferably includes the structural unit (A2-1) derived from the compound represented by the following formula (a2-1), the At least one of the constituent unit (A2-2) of the compound represented by the formula (a2-2) and the constituent unit (A2-3) of the compound represented by the following formula (a2-3), more preferably, one derived from the following formula The structural unit (A2-2) of the compound represented by (a2-2). Further, the structural unit (A2) derived from aliphatic tetracarboxylic dianhydride is preferably selected from the group consisting of the structural unit (A2-1) derived from the compound represented by the following formula (a2-1), the At least one of the constituent unit (A2-2) of the compound and the constituent unit (A2-3) derived from the compound represented by the following formula (a2-3), more preferably derived from the compound represented by the following formula (a2-2) The constituent unit (A2-2). [hua 5]

The compound represented by the above formula (a2-1) is 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA). The compound represented by the above formula (a2-2) is 1,2,4,5-cyclohexanetetracarboxylic dianhydride (HPMDA). The compound represented by the above formula (a2-3) is norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''- Tetracarboxylic dianhydride (CpODA). When the structural unit A includes the structural unit (A2), the deformation recovery property and the colorless transparency become favorable while maintaining the mechanical strength. As described above, since the structural unit A derived from tetracarboxylic dianhydride has structural units (A1) and (A2), the polyimide resin and polyimide film of the present invention have both mechanical properties and colorless transparency Although the reason why it is high in strength and excellent in recovery from deformation has not yet been determined, it is thought to be derived from the rigidity of the perylene group and the degree of freedom of the aliphatic compound.

The proportion of the constituent unit (A1) relative to the constituent unit A is preferably 30-90 mol %, more preferably 40-90 mol %, further preferably 50-90 mol %, still more preferably 50-80 mol % %. The proportion of the constituent unit (A2) relative to the constituent unit A is preferably 10-70 mol %, more preferably 10-60 mol %, more preferably 10-50 mol %, still more preferably 20-50 mol % %.

The ratio of the total of the structural unit (A1) and the structural unit (A2) in the structural unit A is preferably 50 mol % or more, more preferably 70 mol % or more, and further preferably 90 mol % or more. The upper limit of the ratio of the total of the structural unit (A1) and the structural unit (A2) is not particularly limited, but is 100 mol % or less. The structural unit A may be constituted only by the structural unit (A1) and the structural unit (A2).

The molar ratio of the structural unit (A1) and the structural unit (A2) in the structural unit A [(A1)/(A2)], considering the viewpoints of improving mechanical properties, colorless transparency and deformation recovery, should be 20/80 ~90/10, more preferably 30/70~90/10, further preferably 40/60~80/20, still more preferably 50/50~70/30. In particular, from the viewpoint of improving the deformation recovery at high temperature, it is preferably 40/60 to 80/20, more preferably 40/60 to 70/30, and further preferably 40/60 to 60/40.

The polyimide resin of the present invention may contain, in the structural unit A, structural units derived from tetracarboxylic dianhydride other than the structural unit (A1) and the structural unit (A2) within the range that does not impair the effects of the present invention. . Although not particularly limited, pyromellitic dianhydride, 2,3,5, Aromatic tetracarboxylic dianhydrides such as 6-toluenetetracarboxylic dianhydride and 1,4,5,8-naphthalenetetracarboxylic dianhydride. These can be used alone or in combination of two or more.

In addition, in this specification, an aromatic tetracarboxylic dianhydride means the tetracarboxylic dianhydride which contains one or more aromatic rings.

[Constitutional unit B] The constitutional unit B contained in the polyimide of the present invention is a constitutional unit derived from a diamine. The structural unit B contains the structural unit (B1) derived from the compound represented by the following formula (b1). [hua 6]

The compound represented by the above formula (b1) is 2,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (HFBAPP). When the structural unit B contains the structural unit (B1), the mechanical strength can be improved while maintaining the colorless transparency of the obtained polyimide resin.

The ratio of the structural unit (B1) to the structural unit B is preferably 20 mol % or more, more preferably 30 mol % or more, further preferably 40 mol % or more, and still more preferably 50 mol % or more. In particular, from the viewpoint of improving the elongation of the obtained polyimide film, it is more preferably 70 mol % or more, and still more preferably 90 mol % or more. In addition, the upper limit value of the ratio of the structural unit (B1) is not particularly limited, but is 100 mol % or less. The structural unit B may be formed of only the structural unit (B1).

The polyimide resin of the present invention may contain, in the structural unit B, a structural unit derived from a diamine other than the compound represented by the general formula (b1) as the structural unit ( Components other than B1). The diamine other than the compound represented by the general formula (b1) is not particularly limited, and examples thereof include 3,5-diaminobenzoic acid (3,5-DABA), bis[4-(3-amine) phenylphenoxy) phenyl] bismuth (BAPS-M), 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA), 1,4-phenylene Diamine, 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'-diaminobenzylaniline, 1-(4-aminophenyl)-2,3-dihydro-1,3,3-trimethyl base-1H-inden-5-amine, α,α'-bis(4-aminophenyl)-1,4-diisopropylbenzene, N,N'-bis(4-aminophenyl)para Aromatic diamines such as xylylenediamide, 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane, and 1,4-bis(4-aminophenoxy)benzene; 1 Alicyclic diamines such as ,3-bis(aminomethyl)cyclohexane and 1,4-bis(aminomethyl)cyclohexane; aliphatic diamines such as ethylenediamine and hexamethylenediamine amines; and modified polysiloxane diamines. These can be used alone or in combination of two or more. Among these, from the viewpoint of achieving high strength and improving deformation recovery at high temperature, it is preferably selected from the group consisting of 3,5-diaminobenzoic acid (3,5-DABA), bis[4-(3- In the group consisting of aminophenoxy) phenyl] bismuth (BAPS-M) and 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA) at least 1.

In addition, in this specification, aromatic diamine refers to a diamine containing one or more aromatic rings, aliphatic diamine refers to a diamine that does not contain an aromatic ring, and alicyclic diamine refers to aliphatic diamines containing One or more alicyclic diamines.

[Characteristics of polyimide resin, etc.] The number average molecular weight of the polyimide resin of the present invention is preferably 5,000 to 100,000 in view of the mechanical strength of the obtained polyimide film. In addition, the number average molecular weight of the polyimide resin can be measured by gel filtration chromatography or the like.

The polyimide resin of the present invention may be further mixed with various additives within a range that does not impair the effects of the present invention. Examples of additives include antioxidants, light stabilizers, surfactants, flame retardants, plasticizers, and polymer compounds other than the above-mentioned polyimide resins. Examples of the polymer compound include polyimide other than the polyimide resin of the present invention, polycarbonate, polystyrene, polyimide, polyimide imide, polyethylene terephthalate, and the like. Polyester, polyether, polycarboxylic acid, polyacetal, polyphenylene ether, polysaccharide, polybutene, polypropylene, polypropylene amide, polyvinyl chloride, etc.

[Manufacturing method of polyimide resin] The polyamide of the present invention can be produced by reacting a tetracarboxylic acid component containing the compound to which the structural unit (A1) is administered and the compound to which the (A2) is administered, and a diamine component containing the compound to provide the structural unit (B1) Amine resin.

The compound to which the structural unit (A1) can be given includes the compound represented by the formula (a1), but it is not limited to the compound represented by the formula (a1), and can be derived from it within the scope of giving the same structural unit thing. As this derivative, the tetracarboxylic acid corresponding to the tetracarboxylic dianhydride represented by Formula (a1), and the alkyl ester of this tetracarboxylic acid are mentioned. As the compound to give the constituent unit (A1), a compound represented by the formula (a1) (that is, a dianhydride) is suitable. Similarly, as a compound which provides a structural unit (A2), an aliphatic tetracarboxylic dianhydride is mentioned, an alicyclic tetracarboxylic dianhydride is mentioned ideally, and a formula (a2-1 is more ideally mentioned) ), the compound represented by the formula (a2-2) or the formula (a2-3), but it is not limited to these, and may be a derivative thereof within the scope of giving the same structural unit. As the derivatives of the compounds represented by the formula (a2-1), the formula (a2-2) or the formula (a2-3), those corresponding to the formula (a2-1), the formula (a2-2) or the formula ( A2-3) represents the tetracarboxylic acid of tetracarboxylic dianhydride and the alkyl ester of this tetracarboxylic acid. As the compound to give the constituent unit (A2), a compound represented by the formula (a2-1), the formula (a2-2) or the formula (a2-3) (ie, a dianhydride) is suitable.

The tetracarboxylic acid component preferably contains 30-90 mol % of the compound that gives the constituent unit (A1), more preferably 40-90 mol %, further preferably 50-90 mol %, and still more preferably 50-80 mol % Ear%. The tetracarboxylic acid component preferably contains 10-70 mol % of the compound that gives the constituent unit (A2), more preferably 10-60 mol %, further preferably 10-50 mol %, and still more preferably 20-50 mol % Mol%.

The content ratio of the total of the compound to give the structural unit (A1) and the compound to give the structural unit (A2) is preferably 50 mol % or more, more preferably 70 mol % or more, and further preferably 50 mol % or more in the total tetracarboxylic acid component. is more than 90 mol%. The upper limit of the content ratio of the total of the compound to which the constituent unit (A1) is given and the compound to which the constituent unit (A2) is given is not particularly limited, but is 100 mol % or less. The tetracarboxylic acid component may consist only of the compound which gives the structural unit (A1) and the compound which gives the structural unit (A2).

In the tetracarboxylic acid component, the molar ratio [(A1)/(A2)] of the compound to which the constituent unit (A1) is given and the compound to which the constituent unit (A2) is given is considered to improve mechanical properties, colorless transparency and deformation recovery. From the viewpoint, it should be 20/80~90/10, more preferably 30/70~90/10, further suitable for 40/60~80/20, and further suitable for 50/50~70/30. In particular, from the viewpoint of improving the deformation recovery at high temperature, it is preferably 40/60 to 80/20, more preferably 40/60 to 70/30, and further preferably 40/60 to 60/40.

The tetracarboxylic acid component may contain compounds other than the compound to which the constituent unit (A1) is given and the compound to which the constituent unit (A2) is given, and the above-mentioned aromatic tetracarboxylic dianhydrides and their derivatives ( Tetracarboxylic acids, alkyl esters of tetracarboxylic acids, etc.). The compound (that is, the compound other than the compound which gives a structural unit (A1) and a structural unit (A2)) arbitrarily contained in a tetracarboxylic-acid component may be 1 type, or 2 or more types may be sufficient as it.

Although the compound represented by formula (b1) is mentioned as a compound to which a structural unit (B1) is given, it is not limited to it, and a derivative|guide_body may also be a range which gives the same structural unit. As this derivative, diisocyanate corresponding to the diamine represented by formula (b1) can be mentioned. As the compound to give the constituent unit (B1), a compound represented by the formula (b1) (ie, a diamine) is suitable.

The diamine component preferably contains 20 mol % or more of the compound to give the constituent unit (B1), more preferably 30 mol % or more, more preferably 40 mol % or more, still more preferably 50 mol % or more . In particular, from the viewpoint of improving the elongation of the obtained polyimide film, the content is more preferably 70 mol % or more, and still more preferably 90 mol % or more. In addition, the upper limit of the ratio of the compound to be added to the structural unit (B1) is not particularly limited, but is 100 mol % or less. The diamine component may consist only of the compound which gives the structural unit (B1).

The diamine component may contain a compound other than the compound that gives the constituent unit (B1), and the above-mentioned aromatic diamine, alicyclic diamine, aliphatic diamine, modified polysiloxane diamine may be mentioned as the compound. Amines, and their derivatives (diisocyanates, etc.). The compound (that is, the compound other than the compound which gives a structural unit (B1)) arbitrarily contained in a diamine component may be 1 type, and may be 2 or more types.

When manufacturing the polyimide resin of the present invention, the ratio of the addition amount of the tetracarboxylic acid component to the diamine component is preferably 0.9 to 1.1 mol of the diamine component relative to 1 mol of the tetracarboxylic acid component.

When producing the polyimide resin of the present invention, a blocking agent may be used in addition to the above-mentioned tetracarboxylic acid component and the above-mentioned diamine component. As the end-capping agent, monoamines or dicarboxylic acids are suitable. The amount of the introduced end-capping agent is preferably 0.0001-0.1 mol, more preferably 0.001-0.06 mol, relative to 1 mol of the tetracarboxylic acid component. As the ideal monoamine-based blocking agent, methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, 3-methylbenzylamine, 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, etc. Among these, benzylamine and aniline are more suitable. The dicarboxylic acid-based end-capping agent is preferably a dicarboxylic acid, and a part thereof may be ring-closed. The ideal dicarboxylic acid includes phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenone dicarboxylic acid, 3 , 4-benzophenone dicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, etc. Among these, phthalic acid and phthalic anhydride are more suitable.

The method of making the said tetracarboxylic-acid component and a diamine component react is not specifically limited, A well-known method can be used. Specific reaction methods include (1) adding a tetracarboxylic acid component, a diamine component, and a reaction solvent to a reactor, stirring at 10 to 110° C. for 0.5 to 30 hours, and then raising the temperature for imidization. Reaction method, (2) After adding the diamine component and the reaction solvent to the reactor to dissolve it, add the tetracarboxylic acid component, stir at 10~110 ° C for 0.5~30 hours according to the needs, and then heat up to carry out imidization The reaction method, (3) the method of adding the tetracarboxylic acid component, the diamine component, and the reaction solvent to the reactor, and immediately raising the temperature to carry out the imidization reaction, etc.

The reaction solvent used in the production of the polyimide resin may be one that can dissolve the produced polyimide resin without impairing the imidization reaction. For example, an aprotic solvent, a phenol type solvent, an ether type solvent, a carbonate type solvent, etc. are mentioned.

Specific examples of the aprotic solvent include N,N-dimethylisobutylamide, N,N-dimethylformamide, N,N-dimethylacetamide, N- Amide-based solvents such as methyl-2-pyrrolidone, N-methylcaprolactone, 1,3-dimethylimidazolidinone, tetramethylurea, γ-butyrolactone, γ-valerolactone Isolactone-based solvents, phosphorus-containing amide-based solvents such as hexamethylphosphine, hexamethylphosphine triamide, etc., sulfur-containing solvents such as dimethyl sulfoxide, dimethyl sulfoxide, and cyclobutane, acetone , ketone-based solvents such as cyclohexanone and methylcyclohexanone, amine-based solvents such as picoline and pyridine, and ester-based solvents such as acetic acid (2-methoxy-1-methylethyl ester).

Specific examples of the phenol-based 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. Specific examples of the ether-based solvent include 1,2-dimethoxyethane, bis(2-methoxyethyl)ether, and 1,2-bis(2-methoxyethoxy) Ethane, bis[2-(2-methoxyethoxy)ethyl]ether, tetrahydrofuran, 1,4-dioxane, etc. Moreover, as a specific example of a carbonate type solvent, diethyl carbonate, methyl ethyl carbonate, ethylene carbonate, propylene carbonate, etc. are mentioned. Among the above-mentioned reaction solvents, an amide-based solvent or a lactone-based solvent is preferable. Moreover, the said reaction solvent can be used individually or in mixture of 2 or more types.

In the imidization reaction, a Dean-Stark apparatus or the like is preferably used, and the reaction is carried out while removing water generated during production. By doing so, the polymerization degree and the imidization rate can be further improved.

In the above-mentioned imidization reaction, a known imidization catalyst can be used. As the imidization catalyst, an alkali catalyst or an acid catalyst can be mentioned. As the base catalyst, pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, trimethylpyridine, Ethylamine, tripropylamine, tributylamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline and other organic base catalysts, potassium hydroxide, sodium hydroxide, potassium carbonate, Inorganic alkali catalysts such as sodium carbonate, potassium bicarbonate, and sodium bicarbonate. Moreover, crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, toluic acid, hydroxybenzoic acid, terephthalic acid, benzenesulfonic acid, p- Toluenesulfonic acid, naphthalenesulfonic acid, etc. The above imidization catalysts may be used alone or in combination of two or more. Among the above, from the viewpoint of workability, an alkali catalyst is preferably used, an organic alkali catalyst is more preferably used, and triethylamine is further preferably used.

In the case of using the above-mentioned catalyst, the temperature of the imidization reaction is preferably 120 to 250°C, more preferably 160 to 190°C, and further preferably 180 to 190°C from the viewpoints of the reaction rate and inhibition of gelation. In addition, the reaction time is preferably 0.5 to 10 hours after the produced water starts to distill. In addition, the temperature of the imidization reaction when a catalyst is not used is preferably 200 to 350°C.

[Polyimide Varnish] The polyimide varnish of the present invention is obtained by dissolving the polyimide resin of the present invention in an organic solvent. That is, the polyimide varnish of the present invention contains the polyimide resin of the present invention and an organic solvent, and the polyimide resin is dissolved in the organic solvent. The organic solvent is not particularly limited as long as it dissolves the polyimide resin, but it is preferable to use the above-mentioned compounds as the reaction solvent used in the production of the polyimide resin alone or in combination of two or more. The polyimide varnish of the present invention preferably contains 5-60 mass % of the polyimide resin of the present invention, more preferably 5-45 mass %. The viscosity of the polyimide varnish is preferably 0.1~200Pa･s, more preferably 0.5~150Pa･s.

[Polyimide film] The polyimide film of the present invention contains the above-mentioned polyimide resin. Further, the polyimide film of the present invention is preferably composed of the above-mentioned polyimide resin. That is, the polyimide film of the present invention contains a polyimide resin having a structural unit A derived from tetracarboxylic dianhydride and a structural unit B derived from a diamine, and the structural unit A includes The structural unit (A1) derived from the compound represented by the formula (a1) and the structural unit (A2) derived from the aliphatic tetracarboxylic dianhydride, the structural unit B includes the structural unit (B1) derived from the compound represented by the formula (b1). By containing such a polyimide resin, the polyimide film of the present invention has both mechanical properties and colorless transparency, has high strength, and is excellent in deformation recovery.

The production method of the polyimide film of the present invention is not particularly limited, and a known method can be used. For example, the solution containing the polyimide resin of the present invention, or the solution containing the polyimide resin of the present invention and the various additives described above are coated on glass plates, metal plates, plastics, etc. smooth A method of removing solvent components such as an organic solvent contained in the solution after forming it on a support, or after forming it into a film.

The above-mentioned solution containing the polyimide resin may also be the polyimide resin solution itself obtained by the polymerization method. Moreover, at least 1 sort(s) chosen from the compound exemplified above as a solvent for dissolving polyimide resin may be mixed with this polyimide resin solution. The thickness of the polyimide film of the present invention can be easily controlled by adjusting the solid content concentration and viscosity of the solution containing the polyimide resin as described above.

A release agent can also be coated on the surface of the above-mentioned support body according to requirements. The following method is suitable for the method of heating and evaporating the solvent component after coating the solution containing the above-mentioned polyimide resin or the above-mentioned polyimide resin composition on the above-mentioned support. That is, after evaporating the solvent at a temperature of 120°C or less to form a self-supporting film, the self-supporting film is peeled off from the support, and the end of the self-supporting film is fixed at the boiling point of the solvent component used. A polyimide film is produced by drying at a temperature of 350°C or lower. In addition, drying is preferably carried out in a nitrogen atmosphere. The pressure of the drying environment can be any one of reduced pressure, normal pressure, and increased pressure.

The thickness of the polyimide film of the present invention can be appropriately selected according to the application and the like, but is preferably in the range of 1 to 250 μm, more preferably 5 to 100 μm, and further preferably in the range of 10 to 80 μm. With a thickness of 1 to 250 μm, it can be practically used as a self-supporting film.

The polyimide film containing the polyimide resin of the present invention can be suitably used as a film for various members such as color filters, flexible displays, semiconductor parts, and optical members. [Example]

The present invention will be specifically described by the following examples. However, the present invention is not limited by these embodiments.

The physical properties of the polyimide films obtained in the following Examples and Comparative Examples were measured by the methods shown below. (1) Film thickness The film thickness was measured using a micrometer manufactured by Mitutoyo Corporation. (2) Tensile strength, tensile modulus of elasticity The measurement was performed using a tensile testing machine "Strograph VG1E" manufactured by Toyo Seiki Co., Ltd. in accordance with JIS K7127. (3) Tensile elongation at break The tensile elongation at break was measured by a tensile test (measurement of elongation) in accordance with JIS K7127. As a test piece, a width of 10 mm and a thickness of 10 to 70 μm were used. (4) Total light transmittance (evaluation of transparency) The measurement was carried out in accordance with ASTM E313-05, using a color-turbidity simultaneous measuring device "COH7700" manufactured by Nippon Denshoku Kogyo Co., Ltd. (5) Yellowness Index (YI) (evaluation of colorless property) The measurement was carried out in accordance with ASTM E313-05, using a color-turbidity simultaneous measuring device "COH7700" manufactured by Nippon Denshoku Kogyo Co., Ltd. (6) Deformation recovery As shown in Figure 1(a), the polyimide film 1 cut into a width of 10mm × length of 100mm is fixed to R=3mm with a jig, under the conditions of 65°C and 90% relative humidity, or at 70°C, Under dry conditions, let stand for 24 hours or 100 hours. After that, the jig was removed at 23° C. and relative humidity of 50%, and after standing for 170 hours, the recovery of the film was measured at the angle θ shown in FIG. 1( b ) to evaluate the deformation recovery. In addition, the smaller the measurement angle, the better the deformation recovery, and the smaller the numerical value is, the better.

[Example 1] Into a 300 mL 5-neck round-bottomed flask equipped with a stainless steel half-moon-shaped stirring blade, a nitrogen introduction tube, a Dean-Stark apparatus equipped with a cooling tube, a thermometer, and a glass end cap, the 2 of the diamine component was put into it. ,2'-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane (manufactured by SEIKA CORPORATION, hereinafter referred to as HFBAPP) 27.66 g (0.053 mol), γ-butyrolactone as an organic solvent (manufactured by Mitsubishi Chemical Co., Ltd., hereinafter referred to as GBL) 44.8 g, triethylamine (manufactured by Kanto Chemical Co., Ltd., hereinafter referred to as TEA) as an imidization catalyst 2.70 g, and used in the system A solution was obtained by stirring at a temperature of 70° C. under a nitrogen atmosphere at a rotation speed of 150 rpm. To this, 12.23 g (0.027 mol) of 9,9-bis(3,4-dicarboxyphenyl)fornic acid dianhydride (manufactured by JFE Chemical Corporation, hereinafter referred to as BPAF) as a tetracarboxylic acid component and 1 , 2,4,5-cyclohexanetetracarboxylic dianhydride (manufactured by Mitsubishi Gas Chemical Co., Ltd., hereinafter referred to as HPMDA) 5.98g (0.027 moles), GBL 24.1g, then heated with a heating pack, which lasted for The temperature in the reaction system was raised to 190°C in about 20 minutes. The distilled components were collected, and the temperature in the reaction system was maintained at 190° C. for 2 hours while the rotational speed was adjusted in accordance with the increase in viscosity, thereby obtaining a polyimide solution. After that, after the temperature in the reaction system was cooled to 120° C., N,N-dimethylacetamide (manufactured by Mitsubishi Gas Chemical Co., Ltd., hereinafter referred to as DMAc) was added so as to have a predetermined solid content concentration, and the mixture was further stirred for about approx. It was homogenized for 3 hours, and a polyimide varnish (A) with a solid content concentration of 20.0 mass % was obtained.

Then, the polyimide varnish (A) was coated on the PET substrate, maintained at 60°C for 20 minutes, maintained at 80°C for 20 minutes, and maintained at 100°C for 30 minutes, and obtained a self-supporting film by volatilizing the solvent. The transparent film was dried once, and the film was fixed on a stainless steel frame, and the solvent was removed by drying in an air environment of 220° C. for 20 minutes to obtain a polyimide film. The measurement results and evaluation results of physical properties are shown in Table 1.

[Example 2] The amount of HFBAPP was 24.25 g (0.047 mol), and 1.78 g (0.012 mol) of 3,5-diaminobenzoic acid (manufactured by Nippon Pure Chemical Industries, Ltd., hereinafter referred to as 3,5-DABA) was added. , except that the amount of TEA was changed to 0.296 g, the amount of BPAF was changed to 13.40 g (0.029 mol), and the amount of HPMDA was changed to 6.55 g (0.029 mol), by the same method as in Example 1, A polyimide varnish (B) having a solid content concentration of 15.0 mass % was obtained. Using the obtained polyimide varnish (B), by the same method as Example 1, a polyimide film was obtained. The measurement results and evaluation results of physical properties are shown in Table 1.

[Example 3] The amount of HFBAPP was adjusted to 14.58 g (0.028 mol), and 12.16 g (0.028 mol) of bis[4-(3-aminophenoxy)phenyl] bismuth (manufactured by SEIKA CORPORATION, hereinafter referred to as BAPS-M) was added. , except that the amount of TEA was changed to 0.296 g, the amount of BPAF was changed to 12.89 g (0.028 mol), and the amount of HPMDA was changed to 6.31 g (0.028 mol), by the same method as in Example 1. , to obtain a polyimide varnish (C) having a solid content concentration of 18.5% by mass. A thin film was obtained by the same method as Example 1 using the obtained polyimide varnish (C). The measurement results and evaluation results of physical properties are shown in Table 1.

[Example 4] The amount of HFBAPP was adjusted to 19.15 g (0.037 mol), and 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (ChinaTech Chemical (Taijin) Co., Ltd.) was added. system, hereinafter referred to as 6FODA) 12.42g (0.037mol), the amount of TEA was changed to 0.296g, the amount of BPAF was changed to 16.93g (0.037mol), and the amount of HPMDA was changed to 8.28g (0.037mol) , a polyimide varnish (D) having a solid content concentration of 18.5 mass % was obtained by the same method as in Example 1 except for this. A thin film was obtained by the same method as Example 1 using the obtained polyimide varnish (D). The measurement results and evaluation results of physical properties are shown in Table 1.

[Example 5] The amount of HFBAPP was changed to 12.08g (0.023mol), the amount of 6FODA was changed to 18.28g (0.054mol), the amount of BPAF was changed to 17.80g (0.039mol), and the amount of HPMDA was changed to 8.70g (0.039mol) ear), by the same method as in Example 4, a polyimide varnish (E) having a solid content concentration of 18.5 mass % was obtained. Using the obtained polyimide varnish (E), a film was obtained by the same method as in Example 1. The measurement results and evaluation results of physical properties are shown in Table 1.

[Example 6] The amount of HFBAPP was changed to 18.19g (0.035mol), the amount of 6FODA was changed to 11.79g (0.035mol), the amount of BPAF was changed to 22.51g (0.049mol), and the amount of HPMDA was changed to 4.72g (0.021 mol), by the same method as Example 4, the polyimide varnish (F) of 18.5 mass % of solid content concentration was obtained. A thin film was obtained by the same method as Example 1 using the obtained polyimide varnish (F). The measurement results and evaluation results of physical properties are shown in Table 1.

[Example 7] The amount of HFBAPP was changed to 33.49 g (0.065 mol), the amount of BPAF was changed to 14.81 g (0.032 mol), and norbornane-2-spiro-α-cyclopentanone-α'-spiro was added without using HPMDA. -2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride (manufactured by JXTG Energy Corporation, hereinafter referred to as CpODA) 12.42 g (0.032 mol), and other In the same manner as in Example 1, a polyimide varnish (G) having a solid content concentration of 20.0 mass % was obtained. A thin film was obtained by the same method as Example 1 using the obtained polyimide varnish (G). The measurement results and evaluation results of physical properties are shown in Table 1.

[Comparative Example 1] The amount of HFBAPP was changed to 30.52 g (0.059 mol), the amount of TEA was changed to 0.298 g, and the amount of BPAF was changed to 26.98 g (0.059 mol), and HPMDA was not used. In the same manner, a polyimide varnish (H) having a solid content concentration of 18.5 mass % was obtained. A film was obtained by the same method as in Example 1 using the obtained polyimide varnish (H). The measurement results and evaluation results of physical properties are shown in Table 1.

[Comparative Example 2] The amount of HFBAPP was 39.23 g (0.076 mol), the amount of 3,5-DABA was 2.88 g (0.019 mol), and the amount of HPMDA was changed to 21.20 g (0.095 mol) without using BPAF. , a polyimide varnish was produced by the same method as in Example 2, and a polyimide varnish (I) having a solid content concentration of 20% by mass was obtained. Using the obtained polyimide varnish (I), a film was obtained by the same method as in Example 1.

[Comparative Example 3] Instead of using HFBAPP, 2,2'-bis(trifluoromethyl)benzidine (manufactured by Wakayama Seika Co., Ltd., hereinafter referred to as TFMB) 29.81 g (0.093 mol) was used, and the amount of TEA was changed to 0.471 g, except that the amount of BPAF was changed to 21.34 g (0.047 mol), and the amount of HPMDA was changed to 10.43 g (0.047 mol), a solid content concentration of 20.0 was obtained by the same method as in Example 1. Mass % of polyimide varnish (J). A thin film was obtained by the same method as Example 1 using the obtained polyimide varnish (J). The measurement results and evaluation results of physical properties are shown in Table 1.

[Comparative Example 4] The amount of HFBAPP was changed to 29.96 g (0.058 mol), and 8.22 g of 1,4-bis(aminomethyl)cyclohexane (manufactured by Mitsubishi Gas Chemical Co., Ltd., hereinafter referred to as 1,4-BACT) was added. (0.058 mol), except that BPAF was not used, and the amount of HPMDA was changed to 25.91 g (0.116 mol), a polyimide having a solid content concentration of 20.0 mass % was obtained by the same method as in Example 1. Varnish (K). A film was obtained by the same method as Example 1 using the obtained polyimide varnish (K). The measurement results and evaluation results of physical properties are shown in Table 1.

[Comparative Example 5] The amount of HFBAPP was changed to 24.64 g (0.048 mol), the amount of TEA was changed to 0.481 g, and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (Wakayama Seika Industry Co., Ltd.) was added. ), hereinafter referred to as DABPAF) 17.41 g (0.048 mol), without using BPAF, except that the amount of HPMDA was changed to 21.31 g (0.095 mol), by the same method as in Example 1, to obtain A polyimide varnish (L) with a solid content concentration of 20.0% by mass. A thin film was obtained by the same method as Example 1 using the obtained polyimide varnish (L). The measurement results and evaluation results of physical properties are shown in Table 1.

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Polyimide resin Tetracarboxylic acid components (numbers indicate molar ratios) BPAF (a1) 50 50 50 50 50 70 50 100 - 50 - - HPMDA (a2-2) 50 50 50 50 50 30 - - 100 50 100 100 CpODA (a2-3) - - - - - - 50 - - - - - Diamine composition (numbers indicate molar ratios) HFBAPP(b1) 100 80 50 50 30 50 100 100 80 - 50 50 3,5-DABA - 20 - - - - - - 20 - - - BAPS-M - - 50 - - - - - - - - - 6FODA - - - 50 70 50 - - - - - - TFMB - - - - - - - - - 100 - - 1,4-BACT - - - - - - - - - - 50 - DABPAF - - - - - - - - - - - 50 Film evaluation Film thickness [μm] 51 32 47 29 61 67 71 58 44 52 45 54 Tensile strength [MPa] 102 103 105 110 111 111 92 107 91 117 97 97 Tensile modulus of elasticity [GPa] 2.3 2.5 2.6 2.6 2.4 2.3 2.2 2.4 2.3 3.0 2.5 2.6 Tensile elongation at break[%] 14 10 6 9 10 12 15 twenty three 38 9 8 6 Total light transmittance [%] 89.1 89.0 88.4 89.3 89.2 88.8 89.1 88.5 89.9 88.9 90.1 90.4 YI 4.8 3.7 3.5 2.8 4.0 5.8 5.0 7.1 1.4 4.3 2.3 1.3 Deformation recovery [degree (angle)] (65℃, 90%RH, 24h) 35 60 30 50 40 45 50 35 75 60 85 120 Deformation recovery [degree (angle)] (70℃, dry, 100h) 20 15 10 15 20 30 40 40 0 60 10 15

It can be seen from Table 1 that the polyimide films of Examples 1 to 7 have both mechanical properties and colorless transparency, and have high strength, and at the same time, the deformation recovery properties are all under high humidity conditions and drying conditions. for excellent.

1: Polyimide film θ: angle

[ Fig. 1 ] (a) to (b) are schematic diagrams showing a method for measuring the deformation recovery of a polyimide film.

1: Polyimide film

θ: angle

Claims (8)

A polyimide resin having a structural unit A derived from a tetracarboxylic dianhydride and a structural unit B derived from a diamine, the structural unit A comprising a structural unit (A1) derived from a compound represented by the following formula (a1), and a constituent unit (A2) derived from aliphatic tetracarboxylic dianhydride, the constituent unit B comprising a constituent unit (B1) derived from a compound represented by the following formula (b1);

. The polyimide resin according to claim 1, wherein the structural unit (A2) is a structural unit derived from an alicyclic tetracarboxylic dianhydride. The polyimide resin according to claim 1 or 2, wherein the structural unit (A2) is selected from the structural unit (A2-1) derived from the compound represented by the following formula (a2-1), the structural unit (A2-1) derived from the following formula ( At least one of the constituent unit (A2-2) of the compound represented by a2-2) and the group consisting of the constituent unit (A2-3) of the compound represented by the following formula (a2-3);

. The polyimide resin according to any one of claims 1 to 3, wherein the ratio of the constituent unit (B1) to the constituent unit B is 30 mol % or more. The polyimide resin according to any one of claims 1 to 4, wherein the ratio of the constituent unit (A1) to the constituent unit A is 50 to 90 mol %. The polyimide resin according to any one of claims 1 to 5, wherein the structural unit (A2) is a structural unit (A2-2) derived from a compound represented by the following formula (a2-2);

. A polyimide varnish is obtained by dissolving the polyimide resin according to any one of claims 1 to 6 in an organic solvent. A polyimide film containing the polyimide resin according to any one of claims 1 to 6.

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