KR20210007960A - Polyamide-imide resin, polyamide-imide varnish and polyamide-imide film - Google Patents

Abstract

The present invention is a polyamide-imide resin capable of forming a film having excellent mechanical properties, heat resistance, and transparency, and further reducing residual stress, and a polyamide-imide resin comprising the polyamide-imide resin. De varnish and polyamide-imide films are provided. The present invention is a polyamide-imide resin having a structural unit A derived from tetracarboxylic dianhydride, a structural unit B derived from diamine, and a structural unit C derived from aromatic dicarboxylic acid dichloride, wherein the structural unit A is Constituent unit (A-1) derived from a compound represented by the following formula (a-1), and the structural unit B is derived from a compound represented by the following formula (b-1) (B-1) Including, and the structural unit C is a polyamide-imide resin containing a structural unit (C-1) derived from a compound represented by the following formula (c-1), and the polyamide-imide resin. It relates to a polyamide-imide varnish and a polyamide-imide film.

Description

Polyamide-imide resin, polyamide-imide varnish and polyamide-imide film

The present invention relates to polyamide-imide resins, polyamide-imide varnishes and polyamide-imide films.

In general, since polyimide resins have excellent mechanical properties and heat resistance, various uses have been studied in fields such as electric and electronic parts. For example, it is desired to replace a glass substrate used in an image display device such as a liquid crystal display or an OLED display with a plastic substrate for the purpose of reducing the weight or flexibility of the device, and a polyimide film suitable as the corresponding plastic substrate. Research is ongoing. High transparency is required for polyimide films for such applications.

When the varnish applied on a glass support or a silicon wafer is heated to form a polyimide film, residual stress is generated in the polyimide film. When the residual stress of the polyimide film is large, there is a problem that the glass support or the silicon wafer is warped, so that the polyimide film is also required to reduce the residual stress.

On the other hand, attempts have been made to mix or copolymerize polyamide with a polyimide resin, which is a main material of a polyimide film.

In Patent Document 1, a copolymer polyamide-imide film excellent in thermal, mechanical and optical properties, a unit structure derived from 2,2'-bis(trifluoromethyl)benzidine, 4,4'-(hexafluoro Resins having a unit structure derived from isopropylidene)diphthalic anhydride, a unit structure derived from 3,3',4,4'-biphenyltetracarboxylic diacid anhydride, and a unit structure derived from terephthalic acid chloride (TPC) It is disclosed.

In Patent Document 2, an aromatic dian comprising at least one selected from 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, cyclobutanetetracarboxylic dianhydride, and cyclopentanetetracarboxylic dianhydride. Disclosed is a polyamide-imide resin, which is an imide product of a polyamic acid in which a hydride, an aromatic dicarbonyl compound, and an aromatic diamine including 2,2'-bis(trifluoromethyl)benzidine are copolymerized. .

Japanese Patent Publication No. 2014-528490 Japanese Patent Publication No. 2017-503887

As described above, the polyimide film is required to have high transparency and low residual stress, but it is not easy to improve these properties while maintaining excellent mechanical properties and heat resistance.

The present invention has been made in view of this situation, and the subject of the present invention is a polyamide-imide resin capable of forming a film having excellent mechanical properties, heat resistance, and transparency, and further reducing residual stress, and It is to provide a polyamide-imide varnish and a polyamide-imide film comprising a polyamide-imide resin.

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

That is, the present invention relates to the following [1] to [8].

[One]

As a polyamide-imide resin having a structural unit A derived from tetracarboxylic dianhydride, a structural unit B derived from diamine, and a structural unit C derived from aromatic dicarboxylic acid chloride,

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

Constituent unit B includes a structural unit (B-1) derived from a compound represented by the following formula (b-1),

A polyamide-imide resin in which the structural unit C contains a structural unit (C-1) derived from a compound represented by the following formula (c-1).

[Formula 1]

[2]

The proportion of the structural unit (A-1) in the total of the structural unit A and the structural unit C is 10 to 90 mol%,

The polyamide-imide resin according to the above [1], wherein the proportion of the structural unit (C-1) in the total of the structural unit A and the structural unit C is 10 to 60 mol%.

[3]

The polyamide-imide resin according to [1] or [2], wherein the structural unit A contains a structural unit (A-2) derived from a compound represented by the following formula (a-2).

[Formula 2]

[4]

The polyamide-imide resin according to the above [3], wherein the proportion of the structural unit (A-2) in the total of the structural unit A and the structural unit C is 50 mol% or less.

[5]

The polyamide-imide resin according to any one of [1] to [4], wherein the proportion of the structural unit (C-1) in the structural unit C is 50 mol% or more.

[6]

The polyamide-imide resin according to any one of [1] to [5], wherein the proportion of the structural unit (B-1) in the structural unit B is 50 mol% or more.

[7]

A polyamide-imide varnish obtained by dissolving the polyamide-imide resin according to any one of the above [1] to [6] in an organic solvent.

[8]

A polyamide-imide film containing the polyamide-imide resin according to any one of the above [1] to [6].

According to the present invention, it is possible to form a film having excellent mechanical properties, heat resistance, and transparency, and further reducing residual stress.

[Polyamide-imide resin]

The polyamide-imide resin of the present invention has a structural unit A derived from tetracarboxylic dianhydride, a structural unit B derived from diamine, and a structural unit C derived from aromatic dicarboxylic acid chloride,

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

Constituent unit B includes a structural unit (B-1) derived from a compound represented by the following formula (b-1),

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

[Formula 3]

The polyamide-imide resin of the present invention includes a structure in which constituent units A and B are connected by an imide bond in a molecular chain, and a structure in which constituent units C and B are connected by an amide bond. Is to do.

<Constituent Unit A>

The structural unit A is a structural unit derived from a tetracarboxylic dianhydride occupied in the polyamide-imide resin, and includes a structural unit (A-1) derived from a compound represented by the following formula (a-1). In addition to the structural unit (A-1), the structural unit A may contain a structural unit (A-2) derived from a compound represented by the following formula (a-2).

[Formula 4]

In the compound represented by formula (a-1), nobonane-2-spiro-α-cyclopentanone-α'-spiro-2”- nobonane-5,5”,6,6”-tetracarboxylic acid is It is anhydrous.

The compound represented by formula (a-2) is biphenyltetracarboxylic dianhydride (BPDA), and as a specific example, 3,3',4,4'- represented by the following formula (a-2s) Biphenyltetracarboxylic dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA) represented by the following formula (a-2a), the following formula (a) 2,2',3,3'-biphenyltetracarboxylic dianhydride (i-BPDA) represented by -2i) is mentioned.

[Formula 5]

When the structural unit A contains at least the structural unit (A-1), the mechanical properties, heat resistance and transparency of the film are further improved, and the residual stress is further reduced. Further, when the structural unit A includes the structural unit (A-2) in addition to the structural unit (A-1), the mechanical properties of the film are further improved and the residual stress is further reduced.

The proportion of the structural unit (A-1) in the structural unit A is preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 50 mol% or more. The upper limit of the proportion of the structural unit (A-1) is not particularly limited, that is, 100 mol%. Constituent unit A may consist of only constituent units (A-1).

The proportion of the structural unit (A-2) in the structural unit A is preferably 70 mol% or less, more preferably 15 to 60 mol%, and still more preferably 25 to 50 mol%.

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

The proportion of the structural unit (A-1) in the total of the structural unit A and the structural unit C is preferably 10 to 90 mol%, more preferably 30 to 85 mol%, still more preferably 35 to It is 75 mol%.

The proportion of the structural unit (A-2) in the total of the structural unit A and the structural unit C is preferably 50 mol% or less, more preferably 5 to 45 mol%, and still more preferably 10 to 35 It is mole percent.

The ratio of the sum of the structural units (A-1) and (A-2) in the sum of the structural units A and C is preferably 40 to 90 mol%, more preferably 50 to 85 mol% And more preferably 60 to 75 mol%.

The structural unit A may also contain structural units other than the structural units (A-1) and (A-2). The tetracarboxylic acid dianhydride imparting such a structural unit is not particularly limited, but pyromellitic dianhydride, 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, and 4,4' -(Hexafluoroisopropylidene)diphthalic anhydride and other aromatic tetracarboxylic dianhydrides (except for compounds represented by formula (a-2)); Alicyclic tetracarboxylic acid dianhydrides such as 1,2,3,4-cyclobutanetetracarboxylic acid dianhydride and 1,2,4,5-cyclohexanetetracarboxylic acid dianhydride (however, formula (a-1) Excluding compounds represented by); And aliphatic tetracarboxylic dianhydrides, such as 1,2,3,4-butane tetracarboxylic dianhydride, are mentioned.

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

The structural units other than the structural units (A-1) and (A-2) optionally included in the structural unit A may be one type, or may be two or more types.

<Constituent Unit B>

The structural unit B is a structural unit derived from a diamine occupied in the polyamide-imide resin, and includes a structural unit (B-1) derived from a compound represented by the following formula (b-1).

[Formula 6]

The compound represented by formula (b-1) is 2,2'-bis(trifluoromethyl)benzidine.

When the structural unit B contains the structural unit (B-1), the transparency and heat resistance of the film are improved, and residual stress is reduced.

The proportion of the structural unit (B-1) in the structural unit B is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, and particularly preferably It is more than 99 mol%. The upper limit of the proportion of the structural unit (B-1) is not particularly limited, that is, 100 mol%. Constituent unit B may consist of only constituent units (B-1).

Constituent unit B may include constituent units other than the constituent unit (B-1). The diamine giving such a structural unit is not particularly limited, but 1,4-phenylenediamine, p-xylylenediamine, 3,5-diaminobenzoic acid, 1,5-diaminonaphthalene, 2,2'- Dimethylbiphenyl-4,4'-diamine, 4,4'-diaminodiphenylether, 4,4'-diaminodiphenylmethane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4 ,4'-diaminodiphenylsulfone, 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, 4,4'-bis(4-aminophenoxy) Si) biphenyl, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) hexafluoropropane, 2,2' -Bis(trifluoromethyl)-4,4'-diaminodiphenyl ether, and aromatic diamines such as 9,9-bis(4-aminophenyl)fluorene (however, represented by formula (b-1) Compounds are excluded); Alicyclic diamines such as 1,3-bis(aminomethyl)cyclohexane and 1,4-bis(aminomethyl)cyclohexane; And aliphatic diamines, such as ethylenediamine and hexamethylenediamine, are mentioned.

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

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

<Constituent Unit C>

The structural unit C is a structural unit derived from an aromatic dicarboxylic acid chloride occupied in the polyamide-imide resin, and includes a structural unit (C-1) derived from a compound represented by the following formula (c-1).

[Formula 7]

The compound represented by formula (c-1) is terephthalic acid chloride.

When the structural unit C contains the structural unit (C-1), the mechanical properties, heat resistance and transparency of the film are improved, and residual stress is lowered.

The proportion of the structural unit (C-1) in the structural unit C is preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, and particularly preferably It is more than 99 mol%. The upper limit of the proportion of the structural unit (C-1) is not particularly limited, that is, 100 mol%. Constituent unit C may consist of only constituent units (C-1).

The proportion of the structural unit (C-1) in the sum of the structural unit A and the structural unit C is preferably 10 to 60 mol%, more preferably 15 to 50 mol%, and still more preferably 25 to It is 40 mol%.

The structural unit C may include structural units other than the structural unit (C-1). Although it does not specifically limit as an aromatic dicarboxylic acid chloride which gives such a structural unit, 4,4'-biphenyldicarbonyl chloride, 4,4'-oxydibenzoyl chloride, isophthalic acid chloride, etc. are mentioned.

Constituent units other than the constituent unit (C-1) arbitrarily included in the constituent unit C may be one type or two or more types.

The number average molecular weight of the polyamide-imide resin of the present invention is preferably 5,000 to 300,000, more preferably 5,000 to 100,000, from the viewpoint of the mechanical strength of the obtained polyamide-imide film. On the other hand, the number average molecular weight of the polyamide-imide resin can be obtained, for example, from a standard polymethyl methacrylate (PMMA) conversion value by gel filtration chromatography measurement.

The polyamide-imide resin of the present invention includes a polyimide chain (structure formed by imide bonds of structural units A and B) and a polyamide chain (structure formed by amide bonds of structural units C and B). A structure including, etc. are mentioned.

In the polyamide-imide resin of the present invention, the molar ratio (constituent unit A/constituent unit C) of the structural unit A and the structural unit C is preferably 40/60 to 90/10, more preferably 50 /50 to 85/15, more preferably 60/40 to 75/25.

The polyamide-imide resin of the present invention includes a polyimide chain (structure formed by imide bonds of structural units A and B) and a polyamide chain (structure formed by amide bonds of structural units C and B). It is preferable to include as the main structure. Therefore, the ratio of the total of the polyimide chain and the polyamide chain in the polyamide-imide resin of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50 It is mass% or more, and particularly preferably 60 mass% or more.

By using the polyamide-imide resin of the present invention, a film having excellent mechanical properties, heat resistance, and transparency, and further reducing residual stress can be achieved, and suitable physical property values of the film are as follows. .

The tensile modulus of elasticity is preferably 2.5 GPa or more, more preferably 3.0 GPa or more, and still more preferably 4.0 GPa or more.

The tensile strength is preferably 100 MPa or more, more preferably 120 MPa or more, and even more preferably 150 MPa or more.

The glass transition temperature (Tg) is preferably 320°C or higher, more preferably 350°C or higher, and still more preferably 365°C or higher.

When the total light transmittance is made into a film having a thickness of 10 μm, it is preferably 88% or more, more preferably 88.5% or more, and still more preferably 89% or more.

The residual stress is preferably 18.0 MPa or less, more preferably 15.0 MPa or less, and still more preferably 10.0 MPa or less.

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

[Method for producing polyamide-imide resin]

The polyamide-imide resin of the present invention contains a tetracarboxylic acid component containing a compound that imparts the structural unit (A-1) described above, and a compound that imparts the structural unit (B-1) described above. After reacting the said diamine component, it can manufacture by reacting the dicarboxylic acid component containing the compound which imparts a structural unit (C-1).

Examples of the compound to which the structural unit (A-1) is provided include, but are not limited to, the compound represented by the formula (a-1), and may be a derivative thereof within the range to which the same structural unit is provided. As the derivative, tetracarboxylic acid corresponding to the tetracarboxylic dianhydride represented by formula (a-1) (that is, nobonan-2-spiro-α-cyclopentanone-α'-spiro-2”-Novo Nan-5,5", 6,6"-tetracarboxylic acid), and alkyl esters of the tetracarboxylic acid are mentioned. As the compound giving the structural unit (A-1), a compound represented by formula (a-1) (that is, a dianhydride) is preferable.

The tetracarboxylic acid component may contain the compound which gives the structural unit (A-2) mentioned above.

Examples of the compound to impart the structural unit (A-2) include, but are not limited to, the compound represented by the formula (a-2), and may be a derivative thereof as long as the same structural unit is imparted. Examples of the derivatives include tetracarboxylic acids corresponding to tetracarboxylic dianhydrides represented by formula (a-2) and alkyl esters of the tetracarboxylic acids. As the compound giving the structural unit (A-2), a compound represented by formula (a-2) (that is, a dianhydride) is preferable.

The tetracarboxylic acid component contains preferably 30 mol% or more, more preferably 40 mol% or more, and still more preferably 50 mol% or more of the compound that imparts the structural unit (A-1). . The upper limit of the content of the compound giving the structural unit (A-1) is not particularly limited, that is, 100 mol%. The tetracarboxylic acid component may consist of only a compound which gives a structural unit (A-1).

When the tetracarboxylic acid component contains the constituent unit (A-2), the tetracarboxylic acid component preferably contains 70 mol% or less of the compound that provides the constituent unit (A-2), and more preferably Contains 15 to 60 mol%, more preferably 25 to 50 mol%.

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

The tetracarboxylic acid component may contain a compound other than the compound giving the structural unit (A-1) and the compound giving the structural unit (A-2), and as the compound, the aromatic tetracarboxylic acid described above Dianhydride, alicyclic tetracarboxylic dianhydride, and aliphatic tetracarboxylic dianhydride, and their derivatives (tetracarboxylic acid, alkyl ester of tetracarboxylic acid, etc.).

The compound other than the compound which imparts the structural unit (A-1) optionally contained in the tetracarboxylic acid component and the compound which imparts the structural unit (A-2) may be one, or may be two or more.

Examples of the compound to impart the structural unit (B-1) include, but are not limited to, the compound represented by the formula (b-1), and may be a derivative thereof within the range to which the same structural unit is imparted. Examples of the derivatives include diisocyanates corresponding to diamines represented by formula (b-1). As the compound giving the structural unit (B-1), a compound represented by formula (b-1) (ie, diamine) is preferable.

The diamine component contains a compound that imparts the structural unit (B-1), preferably 50 mol% or more, more preferably 70 mol% or more, still more preferably 90 mol% or more, particularly Preferably it contains 99 mol% or more. The upper limit value of the content of the compound that imparts the structural unit (B-1) is not particularly limited, that is, it is 100 mol%. The diamine component may consist of only a compound which imparts a structural unit (B-1).

The diamine component may contain a compound other than the compound that imparts the structural unit (B-1), and as the compound, the aromatic diamine, alicyclic diamine, and aliphatic diamine described above, and their derivatives (diisocyanate, etc.) Can be mentioned.

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

Examples of the compound to impart the structural unit (C-1) include, but are not limited to, the compound represented by the formula (c-1), and may be a derivative thereof within the range to which the same structural unit is imparted. Examples of the derivative include other dicarboxylic acid halides corresponding to dicarboxylic acid chloride represented by formula (c-1) (ie, acid fluoride, acid bromide, and acid iodide). As the compound which imparts the structural unit (C-1), a compound represented by formula (c-1) (ie, acid chloride) is preferable.

The dicarboxylic acid component contains preferably 50 mol% or more, more preferably 70 mol% or more, and still more preferably 90 mol% or more of the compound that imparts the constituent unit (C-1), , Particularly preferably 99 mol% or more. The upper limit of the content of the compound giving the structural unit (C-1) is not particularly limited, that is, 100 mol%. The dicarboxylic acid component may consist only of a compound that imparts the structural unit (C-1).

The dicarboxylic acid component may contain compounds other than the compound that imparts the constituent unit (C-1), and as the compound, the aromatic dicarboxylic acid chloride described above, and other carboxylic acid halides corresponding to them (i.e. , Acid fluoride, acid bromide, and acid iodide).

The number of compounds other than the compound which imparts the structural unit (C-1) optionally contained in the dicarboxylic acid component may be one or two or more.

In the present invention, the total amount of the tetracarboxylic acid component and the dicarboxylic acid component used in the production of the polyamide-imide resin and the added amount ratio of the diamine component ((tetracarboxylic acid component + dicarboxylic acid component)/diamine component, molar ratio ], it is preferable that the diamine component is 0.9 to 1.1 mol with respect to the total 1 mol of the tetracarboxylic acid component and the dicarboxylic acid component.

In the present invention, the amount ratio (tetracarboxylic acid component/dicarboxylic acid component, molar ratio) of the tetracarboxylic acid component and the dicarboxylic acid component used in the production of the polyamide-imide resin is 40/60 to 90/10. This is preferable, 50/50 to 85/15 are more preferable, and 60/40 to 75/25 are still more preferable.

Further, in the present invention, in the production of the polyamide-imide resin, in addition to the above-described tetracarboxylic acid component, dicarboxylic acid component, and diamine component, an end-sealing agent can also be used. As the terminal sealing agent, monoamines or dicarboxylic acids are preferable.

The amount of the terminal sealing agent to be introduced is preferably 0.0001 to 0.1 mol, and particularly preferably 0.001 to 0.06 mol, per 1 mol of the tetracarboxylic acid component.

Examples of monoamine end caps include methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine, and 3-methylbenzylamine , 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, and the like are recommended. Among these, benzylamine and aniline can be used suitably.

Examples of the dicarboxylic acid end-sealing agent include dicarboxylic acids (except for the dicarboxylic acid component described above), and a cyclic carboxylic acid anhydride in which two carboxyl groups in the molecule cause a dehydration condensation reaction, And dicarboxylic acids capable of forming the carboxylic acid anhydride. Specifically, 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, and the like are recommended. Among these, phthalic acid and phthalic anhydride can be suitably used.

There is no particular limitation on the method of reacting the above-described tetracarboxylic acid component, diamine component, and dicarboxylic acid component, and a known method can be used.

As a specific reaction method, (1) a tetracarboxylic acid component, a diamine component, and a reaction solvent are added to the reactor, stirred at room temperature to 80°C for 0.5 to 30 hours, then heated to perform an imidation reaction, and then A method of performing amidation reaction by adding a dicarboxylic acid component and stirring at room temperature to 80° C. for 0.5 to 30 hours, (2) adding a diamine component and a reaction solvent to the reactor to dissolve it, and then adding the tetracarboxylic acid component. , If necessary, the mixture is stirred at room temperature to 80°C for 0.5 to 30 hours, then the temperature is raised to perform the imidation reaction, and then the dicarboxylic acid component is added, and the amidation reaction is stirred at room temperature to 80°C for 0.5 to 30 hours. The method of performing, (3) tetracarboxylic acid component, diamine component, and reaction solvent were put into the reactor, stirred at room temperature to 80°C for 0.5 to 30 hours, and dicarboxylic acid component was added again, and at room temperature to 80°C. Amidation reaction is carried out by stirring for 0.5 to 30 hours, and then the temperature is raised to perform the imidation reaction. (4) After dissolving the diamine component and the reaction solvent in the reactor, the tetracarboxylic acid component is added, and if necessary. Accordingly, the mixture was stirred at room temperature to 80° C. for 0.5 to 30 hours, and dicarboxylic acid component was added again, and if necessary, stirred at room temperature to 80° C. for 0.5 to 30 hours to carry out amidation reaction. Method, (5) tetracarboxylic acid component, diamine component, dicarboxylic acid component, and reaction solvent are added to the reactor, and if necessary, amidation reaction is performed by stirring at room temperature to 80°C for 0.5 to 30 hours, and then The method of performing an imidation reaction by raising temperature, etc. are mentioned.

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

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

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, and bis[2-(2-methoxyethyl)ether. Oxyethoxy)ethyl] ether, tetrahydrofuran, and 1,4-dioxane.

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

Among the above reaction solvents, an amide-based solvent or a lactone-based solvent is preferable. In addition, the above reaction solvents may be used alone or in combination of two or more.

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

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

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

Further, examples of the acid catalyst include crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methylbenzoic acid, oxyanic acid, terephthalic acid, benzenesulfonic acid, paratoluenesulfonic acid, naphthalenesulfonic acid, and the like. The imidation catalyst described above may be used alone or in combination of two or more.

Among the above, from the viewpoint of handling properties, it is preferable to use a base catalyst, more preferably an organic base catalyst, even more preferably triethylamine, and particularly preferably in combination with triethylamine and triethylenediamine. Do.

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

[Polyamide-imide varnish]

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

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

The polyamide-imide varnish of the present invention may be a polyamide-imide solution itself in which a polyamide-imide resin obtained by a polymerization method is dissolved in a reaction solvent, or the polyamide-imide solution It may be that a diluted solvent has been added.

Since the polyamide-imide resin of the present invention has solvent solubility, it can be obtained as a varnish of high concentration stable at room temperature. The polyamide-imide varnish of the present invention preferably contains 5 to 40 mass% of the polyamide-imide resin of the present invention, and more preferably contains 10 to 30 mass%. The viscosity of the polyamide-imide varnish is preferably 1 to 200 Pa·s, more preferably 5 to 150 Pa·s. The viscosity of the polyamide-imide varnish is a value measured at 25°C using an E-type viscometer.

In addition, the polyamide-imide varnish of the present invention is an inorganic filler, an adhesion promoter, a release agent, a flame retardant, an ultraviolet stabilizer, a surfactant, a leveling agent, an antifoaming agent, as long as the required properties of the polyamide-imide film are not impaired. Various additives such as an optical brightener, a crosslinking agent, a polymerization initiator, and a photosensitizer may be included.

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

[Polyamide-imide film]

The polyamide-imide film of the present invention contains the polyamide-imide resin of the present invention. Therefore, the polyamide-imide film of the present invention has excellent mechanical properties, heat resistance, and transparency, and further has low residual stress. The suitable physical property values of the polyamide-imide film of the present invention are as described above.

The method for producing the polyamide-imide film of the present invention is not particularly limited, and a known method can be used. For example, after applying the polyamide-imide varnish of the present invention onto a smooth support such as a glass plate, a metal plate, or plastic, or molding it into a film, organic solvents such as a reaction solvent or a diluting agent contained in the varnish The method of removing a solvent by heating, etc. are mentioned. If necessary, a release agent may be previously applied to the surface of the support.

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

Further, the polyamide-imide film of the present invention can also be produced using a polyamide-amic acid varnish obtained by dissolving a polyamide-amic acid in an organic solvent.

The polyamide-amic acid contained in the polyamide-amic acid varnish is a precursor of the polyamide-imide resin of the present invention, and a tetracarboxylic acid component containing a compound that imparts the above-described structural unit (A-1) And, a compound having an amic acid structure in which a diamine component including a compound that imparts the above-described structural unit (B-1) is bonded by a polyaddition reaction, and provides the above-described structural unit (C-1) It is a product having a structure in which the contained dicarboxylic acid component and the diamine component containing the compound which imparts the above-described structural unit (B-1) are linked by an amide bond. By imidizing this polyamide-amic acid (dehydration-closing), the polyamide-imide resin of the present invention as a final product is obtained.

As the organic solvent contained in the polyamide-amic acid varnish, an organic solvent contained in the polyamide-imide varnish of the present invention may be used.

In the present invention, the polyamide-amic acid varnish may be a polyamide-amic acid solution itself obtained by reaction of the above-described tetracarboxylic acid component, diamine component, and dicarboxylic acid component, or the polyamic acid It may be that a more diluent solvent is added to the solution.

There is no particular limitation on the method of producing a polyamide-imide film using a polyamide-amic acid varnish, and a known method can be used. For example, polyamide-amic acid varnish is coated on a smooth support such as a glass plate, metal plate, or plastic, or molded into a film, and an organic solvent such as a reaction solvent or a diluent solvent contained in the varnish is used for heating. A polyamide-amic acid film is obtained by removing the polyamide-amic acid film, and the polyamide-amic acid in the polyamide-amic acid film is imidized by heating, whereby a polyamide-imide film can be produced.

The heating temperature when drying the polyamide-amic acid varnish to obtain a polyamide-amic acid film is preferably 50 to 120°C. The heating temperature when imidating polyamide-amic acid by heating is preferably 200 to 400°C.

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

The thickness of the polyamide-imide film of the present invention can be appropriately selected depending on the application, etc., preferably in the range of 1 to 100 μm, more preferably 3 to 50 μm, and still more preferably 5 to 30 μm. As the thickness is 1 to 100 μm, practical use as a self-supporting film becomes possible.

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

The polyamide-imide 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 polyamide-imide film of the present invention is particularly suitably used as a substrate for an image display apparatus such as a liquid crystal display or an OLED display.

Example

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

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

(1) solid content concentration

The measurement of the solid content concentration of the varnish was performed by heating a sample at 320° C. x 120 min with a small electric furnace "MMF-1" manufactured by Asone Corporation, and was calculated from the difference in mass of the sample before and after heating.

(2) film thickness

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

(3) Tensile modulus, tensile strength

Tensile modulus and tensile strength were measured in accordance with JIS K7127, using a tensile tester "Strograph VG-1E" manufactured by Dongyang Seiki Co., Ltd. The chuck distance was 50 mm, the test piece size was 10 mm x 50 mm, and the test speed was 20 mm/min. As for both the tensile modulus and tensile strength, the higher the numerical value, the better the mechanical properties.

(4) Glass transition temperature (Tg)

Using the thermomechanical analyzer "TMA/SS6100" manufactured by Hitachi Hi-Tech Science, in the tensile mode, the sample size is 2 mm × 20 mm, the load is 0.1 N, and the temperature rise rate is 10°C/min. The temperature was raised to remove residual stress, and then cooled to room temperature. Thereafter, the elongation of the test piece was measured under the same conditions as the treatment for removing the residual stress, and the place where the inflection point of the elongation was seen was determined as the glass transition temperature. The larger the value of Tg, the better the heat resistance.

(5) Total light transmittance

The total light transmittance was measured in accordance with JIS K7361-1:1997, using a color/turbidity simultaneous measuring instrument "COH400" manufactured by Japan Electric Color Industry Co., Ltd. The closer the total light transmittance is to 100%, the better the transparency.

(6) residual stress

Using the residual stress measuring device "FLX-2320" manufactured by KLA Tenko, on a 4 inch silicon wafer with a thickness of 525 μm±25 μm, which has previously measured the "warpage amount", polyamide-imide varnish or polyamide- The amic acid varnish was applied using a spin coater and prebaked. Thereafter, using a hot air dryer, heat treatment was performed under a nitrogen atmosphere at 350° C. for 30 minutes, and after heating, a silicon wafer with a polyamide-imide film having a thickness of 8 to 20 μm was prepared. The amount of warpage of this wafer was measured using the above-described residual stress measuring apparatus, and the residual stress generated between the silicon wafer and the polyamide-imide film was evaluated.

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

<Tetracarboxylic acid component>

CpODA: Novonan-2-spiro-α-cyclopentanone-α'-spiro-2”-novonane-5,5”,6,6”-tetracarboxylic dianhydride (manufactured by JX Energy Corporation; formula (a Compound represented by -1))

BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride (manufactured by Mitsubishi Chemical Corporation; compound represented by formula (a-2))

<Dicarboxylic acid component>

TPC: terephthalic acid chloride (manufactured by Tokyo Chemical Industry Co., Ltd.; compound represented by formula (c-1))

<Diamine>

TFMB: 2,2'-bis(trifluoromethyl)benzidine (manufactured by Seika Corporation; compound represented by formula (b-1))

<Example 1>

In a 1L 5-neck round bottom flask equipped with stainless steel half-moon stirring blades, nitrogen inlet tube, cooling tube, thermometer, and glass end cap, TFMB 32.024g (0.100 mol), N-methyl-2-pi 63.570 g of rolidone (manufactured by Mitsubishi Chemical Co., Ltd.) was added, and the mixture was stirred at a system temperature of 70°C and a nitrogen atmosphere and a rotation speed of 200 rpm to obtain a solution.

To this solution, 26.907 g (0.070 mol) of CpODA and 15.894 g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) were added at once, and then triethylamine (manufactured by Kanto Chemical Co., Ltd.) as an imidation catalyst. 0.354 g and 0.039 g of triethylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.) were added and heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. The distilled component was collected, and the number of rotations was adjusted according to the viscosity increase, and the temperature in the reaction system was maintained at 190°C and refluxed for 2 hours.

Then, 268.560 g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) was added, the temperature in the reaction system was cooled to 120°C, and then stirred for about 3 hours to make it homogeneous, and the solid content concentration was 15% by mass. A polyimide varnish was obtained. Subsequently, 6.091 g (0.030 mol) of TPC and 204.70 g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) were added, and the mixture was stirred for 2 hours at a system temperature of 50°C and a nitrogen atmosphere, and a rotation speed of 200 rpm, -I got an imide varnish.

Thereafter, polyamide-imide varnish is diluted with N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) to a solid content concentration of 5.0% by mass, and added dropwise to a large excess of methanol to precipitate polyamide-imide powder. Made it. After that, it was suction-filtered with a Kiriyama funnel, and washed twice with a large excess of methanol and ion-exchanged water. It suction-filtered with a Kiriyama funnel and dried at 200 degreeC for 2 hours in a nitrogen atmosphere, and the polyamide-imide powder was obtained.

5.000 g of polyamide-imide powder was dissolved in 45.000 g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) to obtain a polyamide-imide varnish having a solid content concentration of 10.0% by mass.

Thereafter, the obtained polyamide-imide varnish was applied onto a glass or silicon wafer, held on a hot plate at 80° C. for 20 minutes, and then heated at 350° C. in a hot air dryer for 30 minutes under a nitrogen atmosphere. The solvent was evaporated to obtain a film having a thickness of 8 μm. Table 1 shows the results.

<Example 2>

Polyamide-imide in the same manner as in Example 1, except that CpODA was changed from 26.907 g (0.070 mol) to 15.375 g (0.040 mol), and 8.826 g (0.030 mol) of BPDA was additionally added at the same time as CpODA was added. A varnish was produced, and a polyamide-imide varnish having a solid content concentration of 10.0% by mass was obtained.

Using the obtained polyamide-imide varnish, a film was produced by the same method as in Example 1 to obtain a film having a thickness of 9 μm. Table 1 shows the results.

<Comparative Example 1>

In a 1L 5-neck round bottom flask equipped with stainless steel half-moon stirring blades, nitrogen inlet tube, cooling tube, thermometer, and glass end cap, TFMB 32.024g (0.100 mol), N-methyl-2-pi 84.554 g of rolidone (manufactured by Mitsubishi Chemical Co., Ltd.) was added, followed by stirring at a system temperature of 70°C and a nitrogen atmosphere at a rotation speed of 200 rpm to obtain a solution.

To this solution, 38.438 g (0.100 mol) of CpODA and 21.139 g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) were added at once, and then triethylamine (manufactured by Kanto Chemical Co., Ltd.) as an imidation catalyst. 0.506 g and 0.056 g of triethylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.) were added, heated with a mantle heater, and the temperature in the reaction system was raised to 190°C over about 20 minutes. The distilled component was collected and the rotation speed was adjusted according to the viscosity increase, and the temperature in the reaction system was maintained at 190°C, followed by refluxing for 3 hours.

Thereafter, 496.029 g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) was added, and the temperature inside the reaction system was cooled to 120°C, and then stirred for about 3 hours to homogenize, and the solid content concentration of 10% by mass A polyimide varnish was obtained.

Thereafter, the obtained polyimide varnish is applied onto a glass or silicon wafer, and the obtained polyimide varnish is applied and held on a hot plate at 80°C for 20 minutes, and then heated at 400°C in a hot air dryer under a nitrogen atmosphere for 30 minutes to evaporate the solvent. Then, a 14 μm-thick film was obtained. Table 1 shows the results.

[Table 1]

As shown in Table 1, it can be seen that the polyamide-imide films of Examples 1 and 2 are excellent in mechanical properties, heat resistance, and transparency, and further reduce residual stress can be achieved.

On the other hand, the polyimide film of Comparative Example 1 prepared using only CpODA as a tetracarboxylic acid component without using a dicarboxylic acid component has excellent transparency when compared to the polyamide-imide films of Examples 1 and 2 However, it can be seen that the reduction of the residual stress cannot be achieved in that the mechanical properties and heat resistance are inferior, and the residual stress is high.

Claims (8)

As a polyamide-imide resin having a structural unit A derived from tetracarboxylic dianhydride, a structural unit B derived from diamine, and a structural unit C derived from aromatic dicarboxylic acid chloride,
Constituent unit A contains a constituent unit (A-1) derived from a compound represented by the following formula (a-1),
Constituent unit B includes a structural unit (B-1) derived from a compound represented by the following formula (b-1),
A polyamide-imide resin in which the structural unit C contains a structural unit (C-1) derived from a compound represented by the following formula (c-1).
[Formula 1]

The method of claim 1,
The proportion of the structural unit (A-1) in the total of the structural unit A and the structural unit C is 10 to 90 mol%,
The polyamide-imide resin, wherein the proportion of the structural unit (C-1) in the total of the structural unit A and the structural unit C is 10 to 60 mol%. The method according to claim 1 or 2,
A polyamide-imide resin in which the structural unit A contains a structural unit (A-2) derived from a compound represented by the following formula (a-2).
[Formula 2]

The method of claim 3,
The polyamide-imide resin, wherein the proportion of the structural unit (A-2) in the total of the structural unit A and the structural unit C is 50 mol% or less. The method according to any one of claims 1 to 4,
The polyamide-imide resin, wherein the proportion of the structural unit (C-1) in the structural unit C is 50 mol% or more. The method according to any one of claims 1 to 5,
The polyamide-imide resin, wherein the proportion of the structural unit (B-1) in the structural unit B is 50 mol% or more. A polyamide-imide varnish obtained by dissolving the polyamide-imide resin according to any one of claims 1 to 6 in an organic solvent. A polyamide-imide film containing the polyamide-imide resin according to any one of claims 1 to 6.