TWI787499B - Polyamide-imide resin, polyamide-imide varnish, and polyamide-imide film - Google Patents

Abstract

The present invention provides a polyamide-imide resin capable of forming a film having excellent mechanical properties, heat resistance and transparency, while also achieving a reduction in residual stress, and also provides a polyamide-imide varnish and a polyamide-imide film containing this polyamide-imide resin. The invention relates to a polyamide-imide resin containing structural units A derived from a tetracarboxylic dianhydride, structural units B derived from a diamine, and structural units C derived from an aromatic dicarboxylic acid dichloride, wherein the structural units A include a structural unit (A-1) derived from a compound represented by formula (a-1) shown below, the structural units B include a structural unit (B-1) derived from a compound represented by formula (b-1) shown below, and the structural units C include a structural unit (C-1) derived from a compound represented by formula (c-1) shown below, and also relates to a polyamide-imide varnish and a polyamide-imide film that contain this polyamide-imide resin.

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 applications in the fields of electric-electronic parts and the like have been investigated. For example, in order to reduce the weight and flexibility of the device, it is expected to replace the glass substrate used in image display devices such as liquid crystal displays and OLED displays with plastic substrates, and research on polyimide films suitable for such plastic substrates is ongoing. Polyimide films for such applications require high transparency.

When the polyimide film is formed by heating the varnish coated on the glass support or silicon wafer, residual stress will be generated in the polyimide film. If the residual stress of the polyimide film is large, the problem of warpage of the glass support and silicon wafer will occur, so the polyimide film is also required to reduce the residual stress. On the other hand, attempts are being made to mix or copolymerize polyamide with polyimide resin which is the main material of polyimide films. Patent Document 1 discloses a copolymerized polyamide-imide film having excellent thermal, mechanical and optical properties, having a unit structure derived from 2,2'-bis(trifluoromethyl)benzidine, derived from 4 , The unit structure of 4'-(hexafluoroisopropylidene)diphthalic anhydride, the unit structure derived from 3,3',4,4'-biphenyltetracarboxylic dianhydride and the unit structure derived from terephthalic anhydride A resin with a unit structure of triacyl chloride (TPC). Patent Document 2 discloses a polyamide-imide resin, which is an imide of polyamide acid obtained by copolymerizing the following components: Aromatic dianhydrides of one or more of phthalic anhydride, cyclobutane tetracarboxylic dianhydride, and cyclopentane tetracarboxylic dianhydride; aromatic dicarbonyl compounds; including 2,2'-bis(trifluoroform Base) aromatic diamine of benzidine. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese National Publication No. 2014-528490 [Patent Document 2] Japanese National Publication No. 2017-503887

[Problem to be Solved by the Invention]

As mentioned above, high transparency and low residual stress are required for polyimide films, but it is not easy to improve these properties while maintaining excellent mechanical properties and heat resistance. The present invention is formed in view of such a situation. The subject of the present invention is to provide a polyamide-imide resin that can form a film with excellent mechanical properties, heat resistance, and transparency, and can achieve a reduction in residual stress, and A polyamide-imide varnish and a polyamide-imide film containing the polyamide-imide resin are provided. [Means to solve the problem]

The present inventors have found that a polyamide-imide resin containing a combination of specific structural units can solve the above-mentioned problems, and thus completed the invention.

That is, the present invention relates to the following [1] to [8]. [1] A polyamide-imide resin having a constituent unit A derived from tetracarboxylic dianhydride, a constituent unit B derived from diamine, and a constituent unit C derived from aromatic dicarboxylic acid chloride, the The constituent unit A comprises a constituent unit (A-1) derived from a compound represented by the following formula (a-1), and the constituent unit B comprises a constituent 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). [chemical 1]

[4] 如上述[3]所記載之聚醯胺-醯亞胺樹脂，其中，該構成單元(A-2)在該構成單元A及該構成單元C之合計中所佔之比率為50莫耳%以下。 [5] 如上述[1]~[4]中任一項所記載之聚醯胺-醯亞胺樹脂，其中，該構成單元(C-1)在該構成單元C中所佔之比率為50莫耳%以上。 [6] 如上述[1]~[5]中任一項所記載之聚醯胺-醯亞胺樹脂，其中，該構成單元(B-1)在該構成單元B中所佔之比率為50莫耳%以上。 [7] 一種聚醯胺-醯亞胺清漆，係將如上述[1]~[6]中任一項所記載之聚醯胺-醯亞胺樹脂溶解於有機溶劑而成。 [8] 一種聚醯胺-醯亞胺薄膜，含有如上述[1]~[6]中任一項所記載之聚醯胺-醯亞胺樹脂。 [發明之效果][2] The polyamide-imide resin as described in [1] above, wherein the ratio of the structural unit (A-1) to the total of the structural unit A and the structural unit C is 10~ 90 mol%, and 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 as described in the above [1] or [2], wherein the structural unit A includes a structural unit (A-2) derived from a compound represented by the following formula (a-2) ). [Chem 2]

[4] The polyamide-imide resin as described in [3] above, wherein the ratio of the structural unit (A-2) to the total of the structural unit A and the structural unit C is 50 mol Ear % below. [5] The polyamide-imide resin as described in any one of [1] to [4] above, wherein the ratio of the structural unit (C-1) to the structural unit C is 50 More than mole%. [6] The polyamide-imide resin described in any one of the above [1] to [5], wherein the ratio of the structural unit (B-1) to the structural unit B is 50 More than mole%. [7] A polyamide-imide varnish obtained by dissolving the polyamide-imide resin described in any one of [1] to [6] above in an organic solvent. [8] A polyamide-imide film comprising the polyamide-imide resin described in any one of [1] to [6] above. [Effect of Invention]

According to the present invention, it is possible to form a thin film having excellent mechanical properties, heat resistance, and transparency, and to achieve reduction of 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 derived from aromatic di The structural unit C of carboxylic acid chloride, the structural unit A comprises a structural unit (A-1) derived from a compound represented by the following formula (a-1), and the structural unit B comprises a structural unit derived from a compound represented by the following formula (b-1) A structural unit (B-1) of a compound, the structural unit C includes a structural unit (C-1) derived from a compound represented by the following formula (c-1). [Chem 3]

The polyamide-imide resin of the present invention contains the following structures in its molecular chain: a structure formed by linking the structural unit A and the structural unit B with an amide bond, and a structural unit C and the structural unit B linked with the amide bond The resulting structure.

>Constituent unit A> The structural unit A is a structural unit derived from tetracarboxylic dianhydride in the polyamide-imide resin, including a structural unit derived from a compound represented by the following formula (a-1) (A -1). The constitutional unit A may contain a constitutional unit (A-2) derived from a compound represented by the following formula (a-2) in addition to the constitutional unit (A-1). [chemical 4]

The compound represented by formula (a-1) is norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetra Formic dianhydride.

The compound represented by the formula (a-2) is biphenyltetracarboxylic dianhydride (BPDA). Specific examples thereof include: 3,3',4,4'-biphenyl dihydride represented by the following formula (a-2s) Pyrellitic dianhydride (s-BPDA), 2,3,3',4'-biphenyltetracarboxylic dianhydride (a-BPDA) represented by the following formula (a-2a), represented by the following formula (a-2i) 2,2',3,3'-biphenyltetracarboxylic dianhydride (i-BPDA). [chemical 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 residual stress is further reduced. Moreover, by including the structural unit (A-2) in addition to the structural unit (A-1), the structural unit A further improves the mechanical properties of the film and further reduces the residual stress.

The proportion of the constituent unit (A-1) in the constituent unit A is preferably at least 30 mol%, more preferably at least 40 mol%, and even more preferably at least 50 mol%. The upper limit of the ratio of the constituent unit (A-1) is not particularly limited, that is, 100 mol%. Structural unit A may consist only of structural unit (A-1).

The proportion of the constituent unit (A-2) in the constituent unit A is preferably less than 70 mol%, more preferably 15-60 mol%, and even more preferably 25-50 mol%. The ratio of the total of the constituent units (A-1) and (A-2) to the constituent unit A is preferably at least 50 mole%, more preferably at least 70 mole%, more preferably at least 90 mole% , preferably above 99 mol%. The upper limit of the total ratio of the constituent units (A-1) and (A-2) is not particularly limited, that is, 100 mol%. Structural unit A may consist only of structural unit (A-1) and structural unit (A-2).

The proportion of the constituent unit (A-1) in the total of constituent unit A and constituent unit C is preferably 10-90 mole%, more preferably 30-85 mole%, and more preferably 35-75 mole%. good. The proportion of the constituent unit (A-2) in the total of constituent unit A and constituent unit C is preferably 50 mole % or less, more preferably 5-45 mole %, and even more preferably 10-35 mole % . The ratio of the total of the constituent units (A-1) and (A-2) in the total of the constituent units A and C is preferably 40-90 mol%, more preferably 50-85 mol%. 60~75 mol% is even better.

Structural unit A may contain structural units other than structural units (A-1) and (A-2). There are no particular limitations on the tetracarboxylic dianhydride that provides such a constituent unit, and examples include: pyromellitic dianhydride, 9,9'-bis(3,4-dicarboxyphenyl) terflune dianhydride, and 4,4'-(hexafluoroisopropylidene) diphthalic anhydride and other aromatic tetracarboxylic dianhydrides (except for compounds represented by formula (a-2)); 1,2,3,4 - Alicyclic tetracarboxylic dianhydrides such as cyclobutanetetracarboxylic dianhydride and 1,2,4,5-cyclohexanetetracarboxylic dianhydride (except for compounds represented by formula (a-1)); and Aliphatic tetracarboxylic dianhydrides such as 1,2,3,4-butane tetracarboxylic dianhydride. In addition, in this specification, aromatic tetracarboxylic dianhydride means tetracarboxylic dianhydride containing one or more aromatic rings, and alicyclic tetracarboxylic dianhydride means containing one or more alicyclic rings and does not contain aromatic rings. Cyclic tetracarboxylic dianhydrides and aliphatic tetracarboxylic dianhydrides mean tetracarboxylic dianhydrides that do not contain an aromatic ring or an alicyclic ring. Structural units other than the structural units (A-1) and (A-2) arbitrarily contained in the structural unit A may be 1 type, or may be 2 or more types.

>Constituent unit B> The structural unit B is a structural unit derived from a diamine contained in a polyamide-imide resin, including a structural unit (B-1) derived from a compound represented by the following formula (b-1) . [chemical 6]

The compound represented by formula (b-1) is 2,2'-bis(trifluoromethyl)benzidine. Structural unit B improves the transparency and heat resistance of a film, and reduces residual stress by containing structural unit (B-1).

The proportion of the constituent unit (B-1) in the constituent unit B is preferably at least 50 mole %, more preferably at least 70 mole %, more preferably at least 90 mole %, especially at least 99 mole % good. The upper limit of the ratio of the constituent unit (B-1) is not particularly limited, that is, 100 mol%. Structural unit B may consist only of structural unit (B-1).

The structural unit B may contain structural units other than the structural unit (B-1). There are no particular restrictions on diamines that provide such constituent units, and examples include: 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'-diaminodiphenylphenylene, 4,4'-diaminobenzamide, 1-(4-amino Phenyl)-2,3-dihydro-1,3,3-trimethyl-1H-inden-5-amine, α,α'-bis(4-aminophenyl)-1,4-diiso Propylbenzene, N,N'-bis(4-aminophenyl)terephthalamide, 4,4'-bis(4-aminophenoxy)biphenyl, 2,2-bis[4- (4-aminophenoxy)phenyl]propane, 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, 2,2'-bis(trifluoromethyl) -Aromatic diamines such as 4,4'-diaminodiphenyl ether and 9,9-bis(4-aminophenyl) fluorine (except for compounds represented by formula (b-1)); 1 ,3-bis(aminomethyl)cyclohexane, and 1,4-bis(aminomethyl)cyclohexane and other aliphatic diamines; and aliphatic diamines such as ethylenediamine and hexamethylenediamine diamine. In addition, in this specification, an aromatic diamine means a diamine containing one or more aromatic rings, an alicyclic diamine means a diamine containing one or more alicyclic rings and no aromatic ring, and an aliphatic diamine It means a diamine that does not contain an aromatic ring or an alicyclic ring. The structural unit other than the structural unit (B-1) arbitrarily contained in the structural unit B may be 1 type, and may be 2 or more types.

>Constituent unit C> The structural unit C is a structural unit derived from an aromatic dicarboxylic acid chloride contained in a polyamide-imide resin, including a structural unit derived from a compound represented by the following formula (c-1) ( C-1). [chemical 7]

The compound represented by formula (c-1) is terephthaloyl chloride. Structural unit C improves the mechanical properties, heat resistance, and transparency of the film and reduces residual stress by including the structural unit (C-1).

The proportion of the constituent unit (C-1) in the constituent unit C is preferably at least 50 mol %, more preferably at least 70 mol %, more preferably at least 90 mol %, especially at least 99 mol % good. The upper limit of the ratio of the constituent unit (C-1) is not particularly limited, that is, 100 mol%. Structural unit C may consist only of structural unit (C-1). The proportion of the constituent unit (C-1) in the total of constituent unit A and constituent unit C is preferably 10-60 mole%, more preferably 15-50 mole%, and more preferably 25-40 mole%. good.

The structural unit C may contain structural units other than the structural unit (C-1). There are no particular limitations on the aromatic dicarboxylate chlorides that provide such constituent units, and examples include: 4,4'-biphenyldicarboxyl chloride, 4,4'-oxydibenzoyl chloride, m-phenyl Diformyl chloride, etc. The structural unit other than the structural unit (C-1) arbitrarily contained in the structural unit C may be 1 type, and may be 2 or more types.

Considering the mechanical strength of the obtained polyamide-imide film, the number average molecular weight of the polyamide-imide resin of the present invention is preferably 5,000-300,000, more preferably 5,000-100,000. In addition, the number average molecular weight of a polyamide-imide resin can be calculated|required, for example by the standard polymethylmethacrylate (PMMA) equivalent value measured by gel filtration chromatography.

The polyamide-imide resin of the present invention can include polyimide chain (consisting of constituent unit A and constituent unit B through imide bonding structure) and polyamide chain (consisting of constituent unit C and constituent unit B) A structure in which the constituent unit B is bonded by an amide) and the like. The molar ratio of the constituent unit A and the constituent unit C in the polyamide-imide resin of the present invention (constituent unit A/constituent unit C) should be 40/60～90/10, be 50/50～85/ 15 is better, 60/40~75/25 is even better.

The polyamide-imide resin of the present invention preferably comprises a polyimide chain (consisting of constituent unit A and constituent unit B via imide bonded structure) and a polyamide chain (consisting of constituent unit C and constituent unit B) A structure in which unit B is bonded by amide) as the main structure. Therefore, the ratio of the polyimide chain and the sum of the polyamide chains in the polyamide-imide resin of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, and more than 50% by mass. Even more preferably, it is especially preferably at least 60% by mass.

By using the polyamide-imide resin of the present invention, a film with excellent mechanical properties, heat resistance, and transparency can be formed, and the reduction of residual stress can be achieved. The ideal physical properties of the film are as follows.

The tensile modulus of elasticity is preferably at least 2.5 GPa, more preferably at least 3.0 GPa, and even more preferably at least 4.0 GPa. The tensile strength is preferably at least 100 MPa, more preferably at least 120 MPa, and even more preferably at least 150 MPa. The glass transition temperature (Tg) is preferably above 320°C, more preferably above 350°C, and even more preferably above 365°C. When made into a film with a thickness of 10 μm, the total light transmittance should be above 88%, more preferably above 88.5%, and even more preferably above 89%. The residual stress is preferably not more than 18.0 MPa, more preferably not more than 15.0 MPa, and even more preferably not more than 10.0 MPa. In addition, the said physical property value in this invention can be measured specifically by the method as described in an Example.

[Manufacturing method of polyamide-imide resin] The polyamide-imide resin of the present invention can be prepared by making a tetracarboxylic acid component comprising a compound providing the above-mentioned structural unit (A-1) and a diamine component comprising a compound providing the above-mentioned structural unit (B-1) After the reaction, it is produced by reacting with a dicarboxylic acid component including a compound providing a structural unit (C-1).

Examples of the compound providing the structural unit (A-1) include compounds represented by the formula (a-1), but are not limited thereto, and derivatives thereof may be used as long as the same structural unit can be provided. In terms of the derivatives, tetracarboxylic acids corresponding to tetracarboxylic dianhydrides represented by formula (a-1) (that is, norbornane-2-spiro-α-cyclopentanone-α'-spiro -2''-norbornane-5,5'',6,6''-tetracarboxylic acid), and the alkyl ester of the tetracarboxylic acid. As the compound providing the structural unit (A-1), it is preferably a compound represented by formula (a-1) (ie, a dianhydride).

The tetracarboxylic-acid component may contain the compound which provides the said structural unit (A-2). Examples of the compound providing the structural unit (A-2) include compounds represented by the formula (a-2), but are not limited thereto, and derivatives thereof may be used as long as the same structural unit can be provided. As this derivative, the tetracarboxylic acid corresponding to the tetracarboxylic dianhydride represented by formula (a-2), and the alkyl ester of this tetracarboxylic acid are mentioned. As the compound providing the structural unit (A-2), it is preferably a compound represented by formula (a-2) (that is, a dianhydride).

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

When the tetracarboxylic acid component includes the structural unit (A-2), the tetracarboxylic acid component should preferably contain less than 70 mol% of the compound providing the structural unit (A-2), more preferably 15~60 mol%, including 25 ~50 mol% is even better. The tetracarboxylic acid component preferably contains a total of 50 mol% or more of the compound providing the structural unit (A-1) and the compound providing the structural unit (A-2), more preferably 70 mol% or more, including 90 mol% The above is even better, including more than 99 mol%. The upper limit of the total content of the compound providing the constituent unit (A-1) and the compound providing the constituent unit (A-2) is not particularly limited, that is, 100 mol%. The tetracarboxylic acid component may consist only of the compound which provides a structural unit (A-1) and the compound which provides a structural unit (A-2).

Compounds other than the compound providing the structural unit (A-1) and the compound providing the structural unit (A-2) may also be contained in the tetracarboxylic acid component, and the above-mentioned aromatic tetracarboxylic dianhydride, Alicyclic tetracarboxylic dianhydride, aliphatic tetracarboxylic dianhydride, and derivatives thereof (tetracarboxylic acid, alkyl ester of tetracarboxylic acid, etc.). The compounds other than the compound providing the structural unit (A-1) and the compound providing the structural unit (A-2) optionally contained in the tetracarboxylic acid component may be 1 type or 2 or more types.

Examples of the compound providing the structural unit (B-1) include compounds represented by the formula (b-1), but are not limited thereto, and derivatives thereof may be used as long as the same structural unit can be provided. Examples of such derivatives include diisocyanates corresponding to diamines represented by formula (b-1). As the compound providing the structural unit (B-1), it is preferably a compound represented by formula (b-1) (that is, a diamine).

The diamine component preferably contains more than 50 mol% of the compound providing the constituent unit (B-1), more preferably 70 mol% or more, more preferably 90 mol% or more, most preferably 99 mol% or more . The upper limit of the content of the compound providing the constituent unit (B-1) is not particularly limited, that is, 100 mol%. The diamine component may consist only of the compound which provides a structural unit (B-1).

Compounds other than the compound providing the structural unit (B-1) may be contained in the diamine component, and the above-mentioned aromatic diamine, alicyclic diamine, and aliphatic diamine, and their Derivatives (diisocyanates, etc.). The compounds other than the compound providing the structural unit (B-1) which are arbitrarily contained in the diamine component may be one type or two or more types.

Examples of the compound providing the structural unit (C-1) include compounds represented by the formula (c-1), but are not limited thereto, and derivatives thereof may be used as long as the same structural unit can be provided. Such derivatives include other dicarboxylic acid halides (ie, acid fluorides, acid bromides, and acid iodides) corresponding to dicarboxylic acid chlorides represented by the formula (c-1). As the compound providing the constituent unit (C-1), it is preferably a compound represented by formula (c-1) (that is, an acid chloride).

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

Compounds other than the compound providing the constituent unit (C-1) may also be included in the dicarboxylic acid component. For this compound, the above-mentioned aromatic dicarboxylic acid chlorides and other carboxylic acid halides corresponding to them (that is, For acid fluoride, acid bromide, acid iodide). The compounds other than the compound providing the structural unit (C-1) which are arbitrarily contained in the dicarboxylic acid component may be 1 type or 2 or more types.

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

In the present invention, in terms of the feed amount ratio (tetracarboxylic acid component/dicarboxylic acid component, molar ratio) of the tetracarboxylic acid component and the dicarboxylic acid component used in the manufacture of polyamide-imide resin, It is preferably 40/60~90/10, more preferably 50/50~85/15, and even more preferably 60/40~75/25.

In addition, in the present invention, in addition to the aforementioned tetracarboxylic acid component, dicarboxylic acid component, and diamine component, an end-blocking agent may be used in the production of the polyamide-imide resin. As for the blocking agent, monoamines or dicarboxylic acids are preferred. In terms of the feed amount of the end-capping agent to be introduced, relative to 1 mole of the tetracarboxylic acid component, it is preferably 0.0001-0.1 mole, preferably 0.001-0.06 mole. In terms of monoamine blocking agents, for example, methylamine, ethylamine, propylamine, butylamine, benzylamine, 4-methylbenzylamine, 4-ethylbenzylamine, 4-dodecylbenzylamine can be recommended , 3-methylbenzylamine, 3-ethylbenzylamine, aniline, 3-methylaniline, 4-methylaniline, etc. Among them, benzylamine and aniline are suitably used. As far as the dicarboxylic acid-type end-capping agent is concerned, dicarboxylic acids can be cited (but the aforementioned dicarboxylic acid components are excluded), and it is preferable to be a cyclic carboxylic acid anhydride formed by dehydration condensation reaction of two carboxyl groups in the molecule, and capable of The dicarboxylic acid forming the carboxylic anhydride. Specifically, phthalic acid, phthalic anhydride, 4-chlorophthalic acid, tetrafluorophthalic acid, 2,3-benzophenone dicarboxylic acid, 3,4-diphenyl Methanone dicarboxylic acid, cyclohexane-1,2-dicarboxylic acid, cyclopentane-1,2-dicarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, etc. Among them, phthalic acid and phthalic anhydride can be suitably used.

The method of making the said tetracarboxylic-acid component, diamine component, and dicarboxylic-acid component react is not specifically limited, A well-known method can be used. In terms of specific reaction methods, it can be enumerated: (1) Feed the tetracarboxylic acid component, the diamine component, and the reaction solvent into the reactor, stir at room temperature to 80° C. for 0.5 to 30 hours, and then heat up to Carry out imidization reaction, then add dicarboxylic acid component, stir at room temperature ~80°C for 0.5~30 hours to carry out amidation reaction method; (2) Feed diamine component and reaction solvent into the reactor After dissolving it, feed the tetracarboxylic acid component, stir at room temperature ~80°C for 0.5-30 hours as needed, then raise the temperature to carry out the imidization reaction, then add the dicarboxylic acid component, and stir at room temperature Stirring at ~80°C for 0.5~30 hours to implement amidation reaction; (3) Feed tetracarboxylic acid component, diamine component, and reaction solvent into the reactor, and stir at room temperature ~80°C for 0.5~30 hours , then add the dicarboxylic acid component, stir at room temperature to 80°C for 0.5 to 30 hours to implement the amidation reaction, and then increase the temperature to implement the amidation reaction; (4) mix the diamine component and the reaction solvent After feeding the material into the reactor and dissolving it, feed the tetracarboxylic acid component, and stir at room temperature ~80°C for 0.5~30 hours if necessary, then add the dicarboxylic acid component, and stir at room temperature ~80°C for 0.5~30 hours if necessary 30 hours to implement the amidation reaction, and then carry out the method of raising the temperature to implement the amidation reaction; (5) feed the tetracarboxylic acid component, the diamine component, the dicarboxylic acid component, and the reaction solvent into the reactor, According to the need, stir at room temperature to 80°C for 0.5 to 30 hours to carry out the amidation reaction, and then raise the temperature to carry out the method of the amidation reaction, etc.

The reaction solvent used in the production of the polyamide-imide resin may be one that does not interfere with the amidation reaction and imidization reaction, and that can dissolve the produced polyamide-imide resin. Examples thereof include aprotic solvents, phenol-based solvents, ether-based solvents, carbonate-based solvents, and the like.

Specific examples of the aprotic solvent include: N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, N-formaldehyde Amide-based solvents such as caprolactam, 1,3-dimethylimidazolidinone, and tetramethylurea; lactone-based solvents such as γ-butyrolactone and γ-valerolactone; hexamethylphosphoramide Phosphorus-containing amide-based solvents such as hexamethylphosphine triamide; sulfur-containing solvents such as dimethylsulfoxide, dimethylsulfoxide, and cyclobutylene; ketones such as acetone, cyclohexanone, and methylcyclohexanone Amine-based solvents such as picoline and pyridine; ester-based solvents such as acetic acid (2-methoxy-1-methylethyl ester), etc.

Specific examples of phenolic solvents 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 ether solvents include: 1,2-dimethoxyethane, bis(2-methoxyethyl) ether, 1,2-bis(2-methoxyethoxy ) ethane, bis[2-(2-methoxyethoxy)ethyl]ether, tetrahydrofuran, 1,4-dioxane, etc. Moreover, specific examples of carbonate-based solvents include diethyl carbonate, ethylmethyl carbonate, ethylene carbonate, propylene carbonate, and the like. Among the above-mentioned reaction solvents, amide-based solvents or lactone-based solvents are preferable. Moreover, the said reaction solvent may be used individually or in mixture of 2 or more types.

The amidation reaction and the amidation reaction are preferably carried out using a Dean-Stark apparatus or the like, while removing water generated during production. By carrying out such an operation, the degree of polymerization and the imidization rate can be further improved.

A known imidization catalyst can be used for the above-mentioned imidization reaction. As an imidization catalyst, an alkali catalyst or an acid catalyst is mentioned. Examples of alkali catalysts include: pyridine, quinoline, isoquinoline, α-picoline, β-picoline, 2,4-lutidine, 2,6-lutidine, trimethylamine, triethyl Amine, tripropylamine, tributylamine, triethylenediamine, imidazole, N,N-dimethylaniline, N,N-diethylaniline and other organic base catalysts; potassium hydroxide, sodium hydroxide, potassium carbonate, carbonic acid Sodium, potassium bicarbonate, sodium bicarbonate and other inorganic alkali catalysts. In addition, as an acid catalyst, crotonic acid, acrylic acid, trans-3-hexenoic acid, cinnamic acid, benzoic acid, methylbenzoic 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, in view of operability, it is preferable to use an alkali catalyst, more preferably an organic alkali catalyst, even more preferably triethylamine, and particularly preferably a combination of triethylamine and triethylenediamine.

Considering the reaction rate and the inhibition of gelation, the temperature of the imidization reaction is preferably 120-250°C, more preferably 160-200°C. Also, the reaction time is preferably 0.5 to 10 hours after the start of distillation of the produced 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 of the present invention and an organic solvent, and the polyamide-imide resin is dissolved in the organic solvent. The organic solvent is not particularly limited as long as it can dissolve the polyamide-imide resin. It is preferable to use the above-mentioned compound as the reaction solvent used in the manufacture of the polyamide-imide resin alone, or to combine two kinds of solvents. Use a mix of the above. The polyamide-imide varnish of the present invention can also be the polyamide-imide solution itself formed by dissolving the polyamide-imide resin obtained by the polymerization method in a reaction solvent, or it can also be the polyamide-imide solution itself for This polyamide-imide solution is obtained by further adding a diluting solvent.

The polyamide-imide resin of the present invention has solvent solubility, so it can be made into a high-concentration varnish that is stable at room temperature. The polyamide-imide varnish of the present invention preferably contains 5-40% by mass of the polyamide-imide resin of the present invention, more preferably 10-30% by mass. The viscosity of polyamide-imide varnish should be 1~200Pa･s, more preferably 5~150Pa･s. The viscosity of the polyamide-imide varnish is a value measured at 25°C with an E-type viscometer. In addition, the polyamide-imide varnish of the present invention may contain inorganic fillers, adhesion promoters, release agents, barriers, etc. within the range that does not impair the properties required for the polyamide-imide film. Burning agent, ultraviolet stabilizer, surfactant, leveling agent, defoamer, fluorescent whitening agent, crosslinking agent, polymerization initiator, photosensitizer and other additives. The method for producing the polyamide-imide varnish of the present invention is not particularly limited, and known methods can be used.

[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 has low residual stress. The desired physical properties 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 known methods can be used. Examples include coating the polyamide-imide varnish of the present invention on a smooth support such as a glass plate, a metal plate, or plastic, or forming it into a film, and removing the reaction contained in the varnish by heating. Methods of organic solvents such as solvents and dilution solvents, etc. The surface of the aforementioned support may also be pre-coated with a release agent if necessary.

As a method of removing the organic solvent contained in the varnish by heating, the following method is preferable. That is, after the organic solvent is evaporated at a temperature below 120° C. to form a self-supporting film, the self-supporting film is peeled off from the support, the end of the self-supporting film is fixed, and the organic solvent used It is ideal to dry at a temperature above the boiling point of polyamide-imide film. Also, it is suitable for drying under a nitrogen atmosphere. The pressure of the dry environment can be reduced pressure, normal pressure, or increased pressure. The heating temperature when drying the self-supporting film to produce the polyamide-imide film is not particularly limited, but is preferably 200 to 400°C.

Also, the polyamide-imide film of the present invention can be produced using a polyamide-amic acid varnish obtained by dissolving polyamide-amic acid in an organic solvent. The polyamide-amic acid contained in the aforementioned polyamide-amic acid varnish is a precursor of the polyamide-imide resin of the present invention, and has the ability to provide the above-mentioned constituent units (A -1) The tetracarboxylic acid component of the compound and the diamine component of the compound that provides the above-mentioned structural unit (B-1) are bonded to an amide acid structure, and has an amide bond that includes the above-mentioned structural unit. The product of the structure which consists of the dicarboxylic acid component of the compound of (C-1) and the diamine component of the compound which provides the said structural unit (B-1). The polyamide-imide resin of the present invention can be obtained as a final product by imidizing (dehydrating and ring-closing) the polyamide-amic acid. As the organic solvent contained in the aforementioned polyamide-amic acid varnish, the organic solvent contained in the polyamide-imide varnish of the present invention can be used. In the present invention, the polyamide-amic acid varnish may be the polyamide-amic acid solution itself obtained by reacting the above-mentioned tetracarboxylic acid component, diamine component, and dicarboxylic acid component, or it may be the polyamide-amic acid varnish itself. The polyamide acid solution is further added with a diluting solvent.

The method of producing the polyamide-imide film using the polyamide-amic acid varnish is not particularly limited, and known methods can be used. For example, the reaction solvent contained in the varnish can be removed by applying polyamide-amic acid varnish to a smooth support such as a glass plate, metal plate, or plastic, or forming it into a film, and heating organic solvents such as diluting solvents to obtain polyamide-amic acid films, and then use heating to imidize the polyamide-amic acid in the polyamide-amic acid films to produce polyamide -imide film. 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 imidizing polyamide-amic acid by heating is preferably 200 to 400°C. In addition, the imidization method is not limited to thermal imidization, and chemical imidization can also be used.

The thickness of the polyamide-imide film of the present invention can be appropriately selected according to the application, etc., and is preferably 1-100 μm, more preferably 3-50 μm, and even more preferably 5-30 μm. With a thickness of 1-100 μm, it can be used as a self-supporting film practically. The thickness of the polyamide-imide film can be easily controlled by adjusting the solid content 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 suitable for use as a substrate of image display devices such as liquid crystal displays and OLED displays. [Example]

The present invention will be specifically described below using examples. However, the present invention is not limited by these examples. The solid content concentrations of the varnishes obtained in Examples and Comparative Examples and various physical properties of the films were measured by the methods shown below.

(1) Solid content concentration The solid content concentration of varnish was measured by using a small electric furnace "MMF-1" manufactured by AS ONE Co., Ltd. to heat the sample at 320°C×120min, and calculated from the mass difference of the sample before and after heating. (2) Film thickness The film thickness was measured using a micrometer manufactured by Mitutoyo Co., Ltd. (3) Tensile modulus of elasticity, tensile strength The tensile elastic modulus and tensile strength were measured using a tensile testing machine "STROGRAPH VG-1E" manufactured by Toyo Seiki Co., Ltd. in accordance with JIS K7127. The distance between the fixtures is set to 50mm, the size of the test piece is set to 10mm×50mm, and the test speed is set to 20mm/min. Both the tensile modulus of elasticity and the tensile strength are larger, and the mechanical properties are better. (4) Glass transition temperature (Tg) Using the thermomechanical analysis device "TMA/SS6100" manufactured by Hitachi High-Tech Science Co., Ltd., in the tensile mode, the sample size is 2mm×20mm, the load is 0.1N, and the heating rate is 10℃/min. In order to remove the residual stress The temperature is raised to a temperature sufficient to remove the residual stress, and then cooled to room temperature. Thereafter, the elongation of the test piece was measured under the same conditions as the aforementioned treatment for removing residual stress, and the glass transition temperature was obtained when the inflection point of the elongation was observed. 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 device "COH400" manufactured by Nippon Denshoku Industries Co., Ltd. The closer the total light transmittance is to 100%, the better the transparency. (6) Residual stress Use a spin coater to apply polyamide-imide varnish or polyamide-amic acid varnish to the residual stress measurement device "FLX-2320" manufactured by KLA-Tencor, and measure the "warpage amount" in advance. On a 4-inch silicon wafer with a thickness of 525μm±25μm, and pre-baked. Afterwards, use a hot air dryer to perform heat treatment at 350°C for 30 minutes under a nitrogen atmosphere. After heating, a silicon crystal with a polyamide-imide film with a film thickness of 8-20 μm is obtained. round. The amount of warpage of the wafer was measured using the aforementioned residual stress measuring device, and the residual stress generated between the silicon wafer and the polyamide-imide film was evaluated.

The tetracarboxylic-acid component, dicarboxylic-acid component, and diamine component used in the Example and the comparative example, and the abbreviation thereof are as follows. >Tetracarboxylic acid components> CpODA: norbornane-2-spiro-α-cyclopentanone-α'-spiro-2''-norbornane-5,5'',6,6''-tetracarboxylic dianhydride (JX Energy Co., Ltd. Company system; compound represented by formula (a-1)) BPDA: 3,3',4,4'-biphenyltetracarboxylic dianhydride (manufactured by Mitsubishi Chemical Corporation; compound represented by formula (a-2)) >Dicarboxylic acid components> TPC: Terephthaloyl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.; compound represented by formula (c-1)) >Diamine> TFMB: 2,2'-bis(trifluoromethyl)benzidine (manufactured by SEIKA Co., Ltd.; compound represented by formula (b-1))

>Example 1> Put 32.024g (0.100 moles) of TFMB and 63.570g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) In a 1L 5-neck round-bottomed flask with a Dean-Stark apparatus, a thermometer, and a glass end cap, the mixture was stirred at an internal temperature of 70°C under a nitrogen atmosphere at a rotational speed of 200rpm to obtain a solution. 26.907g (0.070 moles) of CpODA and 15.894g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) were added to the solution at one time, and then put into the imidization catalyst 0.354g of triethylamine (manufactured by Kanto Chemical Co., Ltd.) and 0.039g of triethylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and heated with a heating bag (mantle heater), which lasted about 20 minutes. The temperature in the system increased to 190°C. The distilled components were collected, and the rotation speed was adjusted according to the increase in viscosity, while the temperature in the reaction system was kept at 190°C and refluxed for 2 hours. Thereafter, 268.560 g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) was added, the temperature inside the reaction system was cooled to 120° C., and stirred for about 3 hours to make it homogenized to obtain a solid content Polyimide varnish with a concentration of 15% by mass. Then put 6.091g (0.030 moles) of TPC and 204.70g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.), and stir at a temperature of 50°C in the system, under a nitrogen atmosphere, and at a speed of 200rpm. After 2 hours, a polyamide-imide varnish was obtained. Thereafter, the polyamide-imide varnish was diluted with N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) to a solid content concentration of 5.0% by mass, and was added dropwise to a large and excessive amount of The polyamide-imide powder was precipitated in methanol. Thereafter, it was suction-filtered using a Kiriyama funnel, and washed twice with a large amount of excess methanol and ion-exchanged water. The polyamide-imide powder was obtained by suction filtration using a Kiriyama funnel, and drying at 200° C. for 2 hours under a nitrogen atmosphere. Dissolve 5.000 g of polyamide-imide powder in 45.000 g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Corporation) to obtain polyamide-amide with a solid content concentration of 10.0% by mass. Imine varnish. Thereafter, the obtained polyamide-imide varnish is coated on a glass or a silicon wafer, and the heating plate is kept at 80° C. for 20 minutes, and thereafter, in a nitrogen atmosphere, in a hot air dryer at 350° C. The solvent was evaporated by heating for 30 minutes to obtain a film with a thickness of 8 μm. The results are shown in Table 1.

>Example 2> Change CpODA from 26.907g (0.070 mole) to 15.375g (0.040 mole), and add 8.826g (0.030 mole) of BPDA while adding CpODA, except that, use the same method as in Example 1 Method A polyamide-imide varnish was prepared, and a polyamide-imide varnish with a solid content concentration of 10.0% by mass was obtained. Using the obtained polyamide-imide varnish, a film was produced in the same manner as in Example 1, and a film with a thickness of 9 μm was obtained. The results are shown in Table 1.

>Comparative example 1> Put 32.024g (0.100 moles) of TFMB and 84.554g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) In a 1L 5-neck round-bottomed flask with a Dean-Stark apparatus, a thermometer, and a glass end cap, the mixture was stirred at an internal temperature of 70°C under a nitrogen atmosphere at a rotational speed of 200rpm to obtain a solution. 38.438g (0.100 moles) of CpODA and 21.139g of N-methyl-2-pyrrolidone (manufactured by Mitsubishi Chemical Co., Ltd.) were added to the solution at one time, and then put into the imidization catalyst 0.506g of triethylamine (manufactured by Kanto Chemical Co., Ltd.) and 0.056g of triethylenediamine (manufactured by Tokyo Chemical Industry Co., Ltd.), and heated with a heating bag, which lasted about 20 minutes to increase the temperature in the reaction system to 190°C. The distilled components were collected, and the rotation speed was adjusted according to the increase in viscosity, while the temperature in the reaction system was kept at 190°C and refluxed 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 make it homogeneous and obtain a solid content Polyimide varnish with a concentration of 10% by mass. Thereafter, the obtained polyimide varnish is coated on a glass or silicon wafer, kept on a heating plate at 80°C for 20 minutes, and then heated in a hot air dryer at 400°C for 30 minutes under a nitrogen atmosphere The solvent was evaporated to obtain a film with a thickness of 14 µm. The results are shown in Table 1.

[Table 1]

As shown in Table 1, it can be seen that the polyamide-imide films of Examples 1 and 2 have excellent mechanical properties, heat resistance, and transparency, and can achieve reduction of residual stress. On the other hand, it can be seen that the polyimide film of Comparative Example 1, which does not use dicarboxylic acid components, and only uses CpODA as a tetracarboxylic acid component, is compared with the polyamide-imide films of Examples 1 and 2. , although the transparency is excellent, but the mechanical properties and heat resistance are poor, and the residual stress is high, and the reduction of the residual stress cannot be achieved.

Claims (8)

A polyamide-imide resin has a constituent unit A derived from tetracarboxylic dianhydride, a constituent unit B derived from diamine, and a constituent unit C derived from aromatic dicarboxylic acid chloride, the constituent unit A Comprising a structural unit (A-1) derived from a compound represented by the following formula (a-1), the structural unit B comprises a structural unit (B-1) derived from a compound represented by the following formula (b-1), the constituent The unit C comprises a constituent unit (C-1) derived from a compound represented by the following formula (c-1); the polyamide-imide resin comprises a constituent unit C and a constituent unit B bonded by an amide structure,

Such as the polyamide-imide resin of item 1 of the scope of the patent application, wherein the ratio of the constituent unit (A-1) to the total of the constituent unit A and the constituent unit C is 10 to 90 moles %, the proportion of the constituent unit (C-1) in the total of the constituent unit A and the constituent unit C is 10 to 60 mole%. Such as the polyamide-imide resin of claim 1 or 2 of the patent scope, wherein, the constituent unit A comprises a constituent unit (A-2) derived from a compound represented by the following formula (a-2);

The polyamide-imide resin of claim 3, wherein the ratio of the constituent unit (A-2) to the total of the constituent unit A and the constituent unit C is 50 mol% or less . Such as the polyamide-imide resin of claim 1 or 2 of the patent scope, wherein, the proportion of the structural unit (C-1) in the structural unit C is 50 mole % or more. Such as the polyamide-imide resin of claim 1 or 2, wherein the proportion of the constituent unit (B-1) in the constituent unit B is 50 mole % or more. A polyamide-imide varnish is formed by dissolving the polyamide-imide resin in any one of items 1 to 6 of the patent application in an organic solvent. A polyamide-imide film, containing the polyamide-imide resin according to any one of items 1 to 6 in the scope of the patent application.