TW202031733A - Polyamideimide-based resin polyamideimide-based resin varnish optical film and flexible display device - Google Patents

Abstract

Provided is an optical film having excellent appearance quality, the appearance quality of the optical film not being degraded upon contact with alcohol. The optical film comprises a polyamide-imide resin that contains at least: a structural unit derived from a tetracarboxylic acid compound and represented by formula (a); a structural unit derived from a dicarboxylic acid compound and represented by formula (b); and a structural unit derived from a diamine compound and represented by formula (c) [in formula (a), Y represents a tetravalent organic group; in formula (b), Z represents a divalent organic group; in formula (c), X is a divalent organic group; Rc, independently of one another, represents a hydrogen atom or a bond; and * represents a bond]. The polyamide-imide resin includes at least one structural unit selected from the group consisting of a structural unit (a1) and a structural unit (b1). The structural unit (a1) is represented by formula (a) as the structural unit derived from a tetracarboxylic acid compound, where Y is represented by formula (1) [in formula (1), Ra, independently of one another, represents a hydrogen atom, a C1-C12 alkyl group, a C1-C12 alkoxy group or a C6-C12 aryl group; hydrogen atoms included in Ra, independently of one another, may be substituted with halogen atoms; n represents an integer of 0 to 2.

Description

Polyamide imide resin, polyamide imide resin varnish, optical film and flexible display device

The present invention relates to a polyamide imide resin, a polyamide imide resin varnish and an optical film containing the resin, and a flexible display device provided with the optical film.

At present, display devices such as liquid crystal display devices or organic EL (Electroluminescence, electroluminescence) display devices are not only widely used in televisions, but also in various applications such as mobile phones and smart watches. Previously, glass has been used as the front panel of such display devices. However, glass has high transparency and exhibits high hardness depending on the type. On the other hand, it is very rigid and easy to break, so it is difficult to be used as a front panel material for flexible display devices.

Therefore, research is underway to use polymer materials as a substitute for glass. The front panel containing a polymer material is expected to be used in various applications because it easily exhibits flexibility. As one of the flexible polymer materials, for example, optical films using polyimide resins are being studied (Patent Documents 1 and 2). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 2015-521686 [Patent Document 2] Japanese Patent Application Publication No. 2018-119132

[The problem to be solved by the invention]

Although optical films using polyimide-based resins are being studied, there is still a requirement to further improve the optical properties and elastic modulus of optical films. Furthermore, when manufacturing an optical film containing a polyimide-based resin, a step of applying a varnish made by dissolving the resin or the resin precursor in a solvent is performed, depending on the composition of the polyimide-based resin. The types of resin monomers may have insufficient stability of the varnish, and may produce gel in the varnish, which may result in degradation of film-forming properties and optical properties of the optical film.

Therefore, the subject of the present invention is to provide a polyimide-based resin that can manufacture an optical film that maintains a high total light transmittance and has a high elastic modulus and has excellent stability in the state of a varnish. [Technical means to solve the problem]

The inventors of the present invention made diligent studies to solve the above-mentioned problems and found that a polyimide-imide resin having at least a specific structural unit and a weight average molecular weight in a specific range easily maintains the full light of the obtained optical film The transmittance, easy to increase the modulus of elasticity, and excellent stability in the state of varnish, thus completing the present invention.

[式(a)中，Y表示四價有機基， 式(b)中，Z表示二價有機基， 式(c)中，X表示二價有機基， R^c 相互獨立地表示氫原子或鍵結鍵， ＊表示鍵結鍵] 且包含式(a)中之Y係由式(1)： [化2]

[式(1)中，R^a 相互獨立地表示氫原子、碳數1～12之烷基、碳數1～12之烷氧基或碳數6～12之芳基， R^a 中所包含之氫原子可相互獨立地被取代為鹵素原子， n表示0～2之整數， ＊表示鍵結鍵] 所表示之結構單元(a1)作為該源自四羧酸化合物之結構單元，該聚醯胺醯亞胺系樹脂之藉由聚苯乙烯換算所得之重量平均分子量為330,000以上。 [2]如上述[1]所記載之聚醯胺醯亞胺系樹脂，其包含式(2)： [化3]

[式(2)中，Z¹ 表示可具有取代基之二價芳香族基， ＊表示鍵結鍵] 所表示之結構單元(b1)作為源自二羧酸化合物之結構單元，且包含式(3)： [化4]

[式(3)中，X¹ 表示可具有取代基之二價芳香族基， R^c 相互獨立地表示氫原子或鍵結鍵， ＊表示鍵結鍵] 所表示之結構單元(c1)作為源自二胺化合物之結構單元。 [3]如上述[2]所記載之聚醯胺醯亞胺系樹脂，其中式(3)中之X¹ 係由式(4)所表示： [化5]

[式(4)中，R^b 相互獨立地表示碳數1～6之烷基、碳數6～12之芳基、或碳數1～6之烷氧基， R^b 中所包含之氫原子可相互獨立地被取代為鹵素原子， r相互獨立地表示1～4之整數， ＊表示鍵結鍵]。 [4]如上述[1]～[3]中任一項所記載之聚醯胺醯亞胺系樹脂，其包含式(b)中之Z係由式(5)： [化6]

[式(5)中，Ar¹ 相互獨立地表示可具有取代基之二價芳香族基， V表示-O-、二苯基亞甲基、碳數1～12之直鏈狀、支鏈狀或脂環式之二價烴基、-SO₂ -、-S-、-CO-或-N(R¹² )-，此處，該烴基中所包含之氫原子可相互獨立地被取代為鹵素原子， R¹² 表示氫原子、或可經鹵素原子取代之碳數1～12之烷基， m表示1～3之整數，其中，於m為2或3之情形時所存在之複數個V可相互相同，亦可不同， ＊表示鍵結鍵] 所表示之結構單元(b2)作為源自二羧酸化合物之結構單元、及/或包含式(c)中之X係由式(5)所表示之結構單元(c2)作為源自二胺化合物之結構單元、及/或進而包含式(a)中之Y係由式(6)： [化7]

[式(6)中，Ar² 相互獨立地表示可具有取代基之三價芳香族基， s表示0～2之整數， Ar¹ 、V及＊如式(5)中之Ar¹ 、V及＊所定義，其中，於s為2之情形時所存在之複數個V及Ar¹ 可分別相互相同，亦可不同] 所表示之結構單元(a2)作為源自四羧酸化合物之結構單元。 [5]如上述[4]所記載之聚醯胺醯亞胺系樹脂，其中式(5)及式(6)係由式(7)所表示： [化8]

[式(7)中，R¹ 相互獨立地表示氫原子、碳數1～12之烷基、碳數1～12之烷氧基或碳數6～12之芳基，R¹ 中所包含之氫原子可相互獨立地被取代為鹵素原子， R^＊ 表示R¹ 或鍵結鍵， ＊表示鍵結鍵， V表示-O-、二苯基亞甲基、碳數1～12之直鏈狀、支鏈狀或脂環式之二價烴基、-SO₂ -、-S-、-CO-或-N(R¹² )-，此處，該烴基中所包含之氫原子可相互獨立地被取代為鹵素原子，R¹² 表示氫原子、或可經鹵素原子取代之碳數1～12之烷基]。 [6]如上述[5]所記載之聚醯胺醯亞胺系樹脂，其中式(7)係由式(7')： [化9]

[式(7')中，R^＊ 表示氫原子或鍵結鍵，＊表示鍵結鍵] 或式(7")： [化10]

[式(7")中，＊表示鍵結鍵] 所表示。 [7]如上述[1]～[6]中任一項所記載之聚醯胺醯亞胺系樹脂，其中式(1)係由式(1')所表示： [化11]

[＊表示鍵結鍵] 所表示。 [8]一種聚醯胺醯亞胺系樹脂清漆，其包含如上述[1]～[7]中任一項所記載之聚醯胺醯亞胺系樹脂及溶劑。 [9]一種光學膜，其包含如上述[1]～[7]中任一項所記載之聚醯胺醯亞胺系樹脂。 [10]一種可撓性顯示裝置，其具備如上述[9]所記載之光學膜。 [11]如上述[10]所記載之可撓性顯示裝置，其進而具備觸控感測器。 [12]如上述[10]或[11]所記載之可撓性顯示裝置，其進而具備偏光板。 [發明之效果]That is, the present invention includes the following preferable aspects. [1] A polyamide imine resin having at least a structural unit represented by formula (a) derived from a tetracarboxylic acid compound and a structural unit represented by formula (b) derived from a dicarboxylic acid compound , And those derived from the structural unit represented by the formula (c) of the diamine compound: [化1]

[In formula (a), Y represents a tetravalent organic group, in formula (b), Z represents a divalent organic group, in formula (c), X represents a divalent organic group, and R ^c independently represents a hydrogen atom or a bond Bonding, * represents bonding bond] and the Y in formula (a) is derived from formula (1): [化2]

[In the formula (1), R ^a each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, the alkoxy having 1 to 12 carbon atoms or the aryl group of 6 to 12, R ^a contained the Hydrogen atoms can be substituted with halogen atoms independently of each other, n represents an integer from 0 to 2, and * represents a bonding bond] The structural unit (a1) represented as the structural unit derived from the tetracarboxylic acid compound, the polyamide The weight average molecular weight of the imine-based resin converted from polystyrene is 330,000 or more. [2] The polyimide imine resin as described in [1] above, which comprises the formula (2): [化3]

[In formula (2), Z ¹ represents a divalent aromatic group that may have a substituent, * represents a bonding bond] The structural unit (b1) represented as a structural unit derived from a dicarboxylic acid compound, and includes the formula ( 3): [化4]

[In formula (3), X ¹ represents a divalent aromatic group that may have a substituent, R ^c independently represents a hydrogen atom or a bonding bond, and * represents a bonding bond] The structural unit (c1) represented as the source From the structural unit of the diamine compound. [3] The polyamide imine resin as described in the above [2], wherein X ¹ in the formula (3) is represented by the formula (4): [化5]

[In formula (4), R ^b independently represents an alkyl group having 1 to 6 carbons, an aryl group having 6 to 12 carbons, or an alkoxy group having 1 to 6 carbons, and the hydrogen atom contained in R ^b It may be substituted with a halogen atom independently of each other, r each independently represents an integer of 1 to 4, and * represents a bonding bond]. [4] The polyimide-imide-based resin as described in any one of [1] to [3] above, which includes the Z in the formula (b) is derived from the formula (5): [化 6]

[In formula (5), Ar ¹ independently represents a divalent aromatic group that may have a substituent, and V represents -O-, diphenylmethylene, linear or branched chain with 1 to 12 carbon atoms Or alicyclic divalent hydrocarbon group, -SO ₂ -, -S-, -CO- or -N(R ¹² )-, where the hydrogen atoms contained in the hydrocarbon group can be independently substituted with halogen atoms , R ¹² represents a hydrogen atom or an alkyl group with 1 to 12 carbon atoms that can be substituted by a halogen atom, m represents an integer of 1 to 3, wherein when m is 2 or 3, multiple Vs may be mutually The same or different, * represents a bonding bond] The structural unit (b2) represented as a structural unit derived from a dicarboxylic acid compound, and/or the X in the formula (c) is represented by the formula (5) The structural unit (c2) as a structural unit derived from a diamine compound, and/or further comprising Y in formula (a) is derived from formula (6): [化7]

[In formula (6), Ar ² independently represents a trivalent aromatic group which may have a substituent, s represents an integer of 0-2, Ar ¹ , V and * are as in the formula (5) Ar ¹ , V and * Defined, where the plural V and Ar ¹ existing when s is 2 may be the same as each other or different] The structural unit (a2) represented by the tetracarboxylic acid compound-derived structural unit. [5] The polyamide imine resin as described in the above [4], wherein formula (5) and formula (6) are represented by formula (7): [化 8]

[In formula (7), R ¹ independently represents a hydrogen atom, a C 1-12 alkyl group, a C 1-12 alkoxy group, or a C 6-12 aryl group, which is contained in R ¹ Hydrogen atoms can be independently substituted with halogen atoms, R ^＊ represents R ¹ or bonding bond, ＊represents bonding bond, V represents -O-, diphenylmethylene, linear chain with carbon number 1-12 , Branched or alicyclic divalent hydrocarbon group, -SO ₂ -, -S-, -CO- or -N(R ¹² )-, where the hydrogen atoms contained in the hydrocarbon group can be mutually independently It is substituted by a halogen atom, and R ¹² represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms which may be substituted by a halogen atom]. [6] The polyamide imine resin as described in the above [5], wherein the formula (7) is derived from the formula (7'): [化9]

[In formula (7'), R ^* represents a hydrogen atom or a bonding bond, and * represents a bonding bond] or formula (7"): [化10]

[In the formula (7"), * represents a bonding bond]. [7] The polyimide-based resin as described in any one of [1] to [6] above, wherein the formula (1) It is represented by the formula (1'): [化11]

[＊Indicating bonding key]. [8] A polyimide-based resin varnish comprising the polyimide-based resin described in any one of [1] to [7] and a solvent. [9] An optical film comprising the polyimide imine resin as described in any one of [1] to [7] above. [10] A flexible display device including the optical film as described in [9] above. [11] The flexible display device as described in [10] above, which further includes a touch sensor. [12] The flexible display device as described in [10] or [11] above, which further includes a polarizing plate. [Effects of Invention]

According to the polyimide-imide resin of the present invention, an optical film that maintains a high total light transmittance and has a high elastic modulus can be provided. In addition, the polyimide-based resin of the present invention has good stability in the state of varnish.

Hereinafter, embodiments of the present invention will be described in detail. Furthermore, the scope of the present invention is not limited to the embodiments described here, and various changes can be made without departing from the scope of the present invention.

[式(a)中，Y表示四價有機基， 式(b)中，Z表示二價有機基， 式(c)中，X表示二價有機基， R^c 相互獨立地表示氫原子或鍵結鍵， ＊表示鍵結鍵] 且包含式(a)中之Y係由式(1)： [化13]

[式(1)中，R^a 相互獨立地表示氫原子、碳數1～12之烷基、碳數1～12之烷氧基或碳數6～12之芳基， R^a 中所包含之氫原子可相互獨立地被取代為鹵素原子， n表示0～2之整數， ＊表示鍵結鍵] 所表示之結構單元作為該源自四羧酸化合物之結構單元，該聚醯胺醯亞胺系樹脂之藉由聚苯乙烯換算所得之重量平均分子量為330,000以上。於本說明書中，將式(a)中之Y係由式(1)所表示之結構單元亦稱為「結構單元(a1)」。The polyamide imine resin of the present invention has at least a structural unit represented by formula (a) derived from a tetracarboxylic acid compound, a structural unit represented by formula (b) derived from a dicarboxylic acid compound, and a source From the structural unit represented by the formula (c) of the diamine compound: [化12]

[In formula (a), Y represents a tetravalent organic group, in formula (b), Z represents a divalent organic group, in formula (c), X represents a divalent organic group, and R ^c independently represents a hydrogen atom or a bond Bonding, ＊ means bonding bond] and including Y in formula (a) is derived from formula (1): [化13]

[In the formula (1), R ^a each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, the alkoxy having 1 to 12 carbon atoms or the aryl group of 6 to 12, R ^a contained the Hydrogen atoms can be substituted with halogen atoms independently of each other, n represents an integer from 0 to 2, and * represents a bonding bond] The structural unit represented as the structural unit derived from the tetracarboxylic acid compound, the polyamide imine The weight average molecular weight of the resin converted from polystyrene is 330,000 or more. In this specification, the structural unit represented by formula (1) where Y in formula (a) is also referred to as "structural unit (a1)".

The polyamide imine resin of the present invention has at least a structural unit represented by formula (a) derived from a tetracarboxylic acid compound (hereinafter, also referred to as "structural unit (a)"), and is derived from a dicarboxylic acid compound The structural unit represented by formula (b) (hereinafter, also referred to as "structural unit (b)"), and the structural unit represented by formula (c) derived from a diamine compound (hereinafter, also referred to as "structural unit (c)"), and includes the structural unit (a1) represented by the formula (1) in Y in the formula (a) as the structural unit (a) derived from the tetracarboxylic acid compound. The polyimide imine resin of the present invention usually has a plurality of structural units (a), a plurality of structural units (b), and a plurality of structural units (c), and optionally a plurality of other structural units. In this specification, the so-called polyamidoimide resin of the present invention includes the structural unit (a1) represented by formula (1) represented by Y in formula (a) as a structural unit derived from a tetracarboxylic acid compound ( a) means that among the multiple structural units (a) possessed by the polyimide imine resin, at least a part of the structural units (a) are represented by formula (a) and Y is represented by formula (1) Structural unit (a1). The above description also complies with the same other descriptions in this manual. Furthermore, the bonding bonds in formulas (a) to (c) are bonding bonds to adjacent structural units.

[式(D)中，Y表示四價有機基， X表示二價有機基， ＊表示鍵結鍵] 所表示之醯亞胺鍵，且包含於聚醯胺醯亞胺系樹脂中，源自二羧酸化合物之結構單元(b)及源自二胺化合物之結構單元(c)形成式(E)： [化15]

[式(E)中，Z及X相互獨立地表示二價有機基， ＊表示鍵結鍵] 所表示之醯胺鍵，且包含於聚醯胺醯亞胺系樹脂中。再者，式(D)中之具有Y及4個羰基之部分相當於源自四羧酸化合物之結構單元(a)，式(E)中之具有Z及2個羰基之部分相當於源自二羧酸化合物之結構單元(b)，式(D)及式(E)中之具有X及胺基之部分相當於源自二胺化合物之結構單元(c)。再者，於式(D)及式(E)中之相當於源自二胺化合物之結構單元(c)之部分，表示二價有機基之X係一個鍵結鍵鍵結於胺基，另一個＊所表示之鍵結鍵鍵結於相鄰之結構單元。於式(D)及式(E)所表示之結構單元重複之情形時，鍵結於相鄰之結構單元之＊所表示之鍵結鍵鍵結於式(D)或式(E)中之胺基部分。因此，亦可謂式(D)及式(E)中之具有X及胺基之部分係相當於源自二胺化合物之結構單元(c)之部分。The polyamide imine resin of the present invention has at least a structural unit (a), a structural unit (b) and a structural unit (c). Here, the structural unit (a) derived from a tetracarboxylic acid compound and the structural unit (a) derived from two The structural unit (c) of the amine compound usually forms the formula (D): [化14]

[In formula (D), Y represents a tetravalent organic group, X represents a divalent organic group, and * represents a bonding bond] The amide bond represented by the formula (D) is contained in the polyamide amide resin, derived from The structural unit (b) of the dicarboxylic acid compound and the structural unit (c) derived from the diamine compound form the formula (E): [化15]

[In formula (E), Z and X independently represent a divalent organic group, and * represents a bonding bond] The amide bond represented by it is contained in the polyimide imine-based resin. Furthermore, the part having Y and 4 carbonyl groups in formula (D) corresponds to the structural unit (a) derived from the tetracarboxylic acid compound, and the part having Z and 2 carbonyl groups in formula (E) corresponds to the part derived from The structural unit (b) of the dicarboxylic acid compound, the part having X and the amino group in the formula (D) and the formula (E) corresponds to the structural unit (c) derived from the diamine compound. Furthermore, in formula (D) and formula (E), the part corresponding to the structural unit (c) derived from the diamine compound indicates that X of the divalent organic group is bonded to the amine group by a bonding bond, and A bond represented by * is bonded to adjacent structural units. When the structural units represented by formula (D) and formula (E) are repeated, the bonding bond represented by * of the adjacent structural unit is bonded in formula (D) or formula (E) Amino moiety. Therefore, it can be said that the part having X and the amino group in the formula (D) and the formula (E) corresponds to the part derived from the structural unit (c) of the diamine compound.

The polyamide imine-based resin of the present invention includes the structural unit (a1) represented by the formula (1) as Y in the formula (a) as the structural unit (a) derived from a tetracarboxylic acid compound. In this case, the polyimide-based resin of the present invention has a Y-based structural unit (D) represented by formula (1). The * in formula (D) and formula (E) represents the bonding bond to the adjacent structural unit.

The polyamide imine resin of the present invention only needs to have at least the Y in the formula (a) is the structural unit (a1) derived from the tetracarboxylic acid compound represented by the formula (1), and is derived from the dicarboxylic acid compound The structural unit (b) and the structural unit (c) derived from the diamine compound may be sufficient, and may further have structural units derived from other tetracarboxylic acid compounds other than the above, and/or derived from other monomers other than the above The structural unit. Specifically, the polyamide imine resin of the present invention has at least one or two or more types of Y in the formula (a) is a structural unit derived from a tetracarboxylic acid compound represented by the formula (1) ( a1) One or more structural units derived from dicarboxylic acid compounds (b), and one or more structural units derived from diamine compounds (c), in addition to these, Furthermore, there are one or more structural units derived from tetracarboxylic acid compounds (such as the following structural units (a2)) and/or tetracarboxylic acid compounds in which Y in the formula (a) does not match the formula (1) , One or two or more structural units derived from other monomers other than dicarboxylic acid compounds and diamine compounds (hereinafter, also referred to as structural units (d)).

The polyamide imine-based resin of the present invention includes the structural unit (a1) represented by the formula (1) as Y in the formula (a) as the structural unit (a) derived from a tetracarboxylic acid compound. The structural unit represented by formula (1) is included in the polyimide-based resin by making the polyimide-based resin include the structural unit (a1). The structural unit represented by the formula (1) is a relatively rigid structure, and the skeleton of the polyimide-based resin includes a rigid part. The result is surprising, and it is easy to improve the elastic modulus and total light transmittance of the obtained optical film.

In addition, the polyamide-imide-based resin of the present invention can easily improve the elastic modulus and optical properties of the obtained optical film by making the weight average molecular weight obtained by polystyrene conversion to be 330,000 or more, and can increase the content The stability of the varnish of the polyimide resin. In addition, in this specification, the varnish containing polyimide-imide resin is also called "resin varnish". When the weight average molecular weight of the polyamide resin is less than 330,000 in terms of polystyrene, it is difficult to suppress the gelation of the resin varnish with time. As a result, it is clear when the optical film is manufactured The film-forming properties of the resin varnish decreased and/or the optical properties of the obtained optical film decreased. Although the reason is not clear, it is believed to be in the polyimide-imide resin containing the Y in formula (a) and the structural unit (a1) represented by formula (1) in the adjacent polymer chain In the meantime, the part having the structural unit represented by the formula (1) tends to accumulate, so the intermolecular interaction of the polyimide-based resin is likely to increase. In addition, it is considered that the amine group and the carboxyl group that may be present in the terminal portion of the polyamide imine resin are likely to undergo hydrogen bonding between polymer chains. When the weight-average molecular weight of polyamide-imide-based resin converted from polystyrene is less than 330,000, the structural unit represented by formula (1), and the amine group and carboxyl group that may exist in the terminal part As a result, the interaction between polymer chains becomes too high, so the varnish is easy to gel with time. Furthermore, the present invention is not limited in any way by the aforementioned mechanism.

The polyamide-imide resin of the present invention has a weight average molecular weight of 330,000 or more converted from polystyrene, which can easily improve the stability of the varnish, and the optical properties, elastic modulus, surface hardness and From the standpoint of bending resistance, it is preferably 400,000 or more, more preferably 420,000, still more preferably 440,000 or more, and particularly preferably 460,000 or more, it is easy to improve the solubility of the polyimide-based resin in solvents and is easy to From the viewpoint of improving the extensibility and processability of the optical film, it is preferably 1,000,000 or less, more preferably 800,000 or less, still more preferably 700,000 or less, and particularly preferably 600,000 or less. The weight average molecular weight can be measured by, for example, GPC (gel permeation chromatograph) and calculated by standard polystyrene conversion. For example, it can be calculated by the method described in the examples.

The method for adjusting the weight average molecular weight of the polyimide-based resin is not particularly limited. For example, in order to obtain the polyimide-based resin, it is preferable to use a tetracarboxylic acid compound, a dicarboxylic acid compound, and a diamine compound During the copolymerization, the ratio of the molar amount of the diamine compound to the total molar amount of the tetracarboxylic acid compound and the dicarboxylic acid compound is adjusted so that it becomes about 1.0, thereby producing a weight average molecular weight having the above-mentioned desired range The polyamide imine resin. Specifically, the ratio of the molar amount of the diamine compound when the total molar amount of the tetracarboxylic acid compound and the dicarboxylic acid compound is set to 1 (the molar amount of the diamine compound/(the molar amount of the tetracarboxylic acid compound and the dicarboxylic acid compound) The total molar amount of the acid compound), this ratio is also referred to as the "amine ratio" hereinafter) is preferably 0.95 or more, more preferably 0.97 or more, still more preferably 0.98 or more, and particularly preferably 0.99 or more, it is easy to polymerize From the viewpoint of adjusting the weight average molecular weight of the amidoimide-based resin to a preferred range, it is preferably 1.05 or less, more preferably 1.03 or less, still more preferably 1.02 or less, and particularly preferably 1.01 or less.

[式(1)中，R^a 相互獨立地表示氫原子、碳數1～12之烷基、碳數1～12之烷氧基或碳數6～12之芳基， R^a 中所包含之氫原子可相互獨立地被取代為鹵素原子， n表示0～2之整數， ＊表示鍵結鍵] 所表示之結構單元(a1)作為源自四羧酸化合物之結構單元。本發明之聚醯胺醯亞胺系樹脂可具有式(a)中之Y係由式(1)所表示之1種結構單元(a1)，亦可具有式(a)中之Y係由式(1)所表示之2種以上之結構單元(a1)。The polyamide imine resin of the present invention includes the Y in the formula (a) is composed of the formula (1): [化16]

[In the formula (1), R ^a each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, the alkoxy having 1 to 12 carbon atoms or the aryl group of 6 to 12, R ^a contained the Hydrogen atoms may be substituted with halogen atoms independently of each other, n represents an integer of 0-2, and * represents a bonding bond] The structural unit (a1) represented by the tetracarboxylic acid compound-derived structural unit. The polyamide imine resin of the present invention may have one type of structural unit (a1) represented by formula (1) where Y in formula (a) is represented by formula (1), or may have Y in formula (a) by formula (1) Two or more structural units (a1) as indicated.

R ^a in the formula (1) independently represents a hydrogen atom, an alkyl group having 1 to 12 carbons, an alkoxy group having 1 to 12 carbons, or an aryl group having 6 to 12 carbons, and the hydrogen contained in R ^a Atoms can be substituted with halogen atoms independently of each other. In one preferred aspect of the present invention, it is easy to increase the total light transmittance of the optical film using the viewpoint polyamide-imide resin is obtained and the number of terms of elastic modulus, R ^a is preferably a hydrogen atom.

Examples of the alkyl group having 1 to 12 carbons include linear, branched, or alicyclic alkyl groups having 1 to 12 carbons. Examples of linear, branched or alicyclic alkyl groups having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, and Tributyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2-ethylpropyl, n-hexyl, n-heptyl, n-octyl, tertiary octyl, n-nonyl, n- Decyl, cyclopentyl, cyclohexyl, etc. The alkyl group having 1 to 12 carbon atoms may be a linear alkyl group, a branched chain alkyl group, or an alicyclic alkyl group containing an alicyclic hydrocarbon structure. The carbon number of the alkyl group having 1 to 12 carbons is preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. The above-mentioned C1-C12 alkyl group may be one of at least one hydrogen atom independently substituted with a halogen atom, C1-C4 alkyl group, C1-C4 alkoxy group, hydroxyl group, or carboxyl group base. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. Here, when an alkyl group having 1 to 12 carbon atoms is substituted with a substituent containing carbon atoms (for example, an alkyl group having 1 to 4 carbon atoms), the number of carbon atoms contained in the substituent is not included in the number of carbon atoms Among the carbon numbers of the alkyl group of 1-12. For example, the above-mentioned alkyl group having 1 to 12 carbon atoms is substituted with an alkyl group having 1 to 4 carbon atoms, and the main chain is an alkyl group having 1 to 12 carbon atoms, and at least one hydrogen atom of the alkyl group is substituted with carbon The number of alkyl groups from 1 to 4. As long as the number of carbon atoms in the alkyl portion of the main chain is 1-12, the number of carbon atoms in the entire alkyl group may exceed 12. Furthermore, in the case of a group having no more than 12 carbon atoms as the entire alkyl group, a group in which an alkyl group having 1 to 12 carbon atoms is substituted by an alkyl group having 1 to 4 carbon atoms is also included in the group having 1 to 12 carbon atoms. The group in the definition of branched alkyl.

Examples of alkoxy groups having 1 to 12 carbon atoms include: methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, and pentoxy Group, hexyloxy, cyclohexyloxy, heptyloxy, octyloxy, nonyloxy and decyloxy, etc. The alkyl moiety and/or the alkylene moiety in the alkoxy group having 1 to 12 carbon atoms may be linear, branched, or alicyclic. The carbon number of the alkoxy group having 1 to 12 carbons is preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. The above-mentioned alkoxy group having 1 to 12 carbon atoms may be at least one hydrogen atom independently substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a hydroxyl group, or a carboxyl group. The base. Examples of the halogen atom include the atoms described above. Here, when the alkoxy group having 1 to 12 carbon atoms is substituted with a substituent containing carbon atoms, the number of carbon atoms contained in the substituent is not included in the number of carbon atoms of the alkoxy group having 1 to 12 carbon atoms in.

Examples of aryl groups having 6 to 12 carbon atoms include phenyl, tolyl, xylyl, naphthyl, biphenyl and the like. The carbon number of the aryl group having 6 to 12 carbons is preferably 6 or 10 or 12. The above-mentioned aryl group having 6 to 12 carbons may be one of at least one hydrogen atom independently substituted with a halogen atom, an alkyl group having 1 to 4 carbons, an alkoxy group having 1 to 4 carbons, a hydroxyl group, or a carboxyl group. base. Examples of the halogen atom include the atoms described above. Here, when the aryl group having 6 to 12 carbon atoms is substituted with a substituent containing carbon atoms, the number of carbon atoms contained in the substituent is not included in the carbon number of the aryl group having 6 to 12 carbon atoms.

Hydrogen atoms contained in the R ^a independently of each other be substituted with a halogen atom. Examples of the halogen atom include the atoms described above.

In formula (1), n represents an integer from 0 to 2. From the viewpoint of easily improving the total light transmittance and elastic modulus of an optical film obtained by using polyimide-imide resin, n is preferably 0 Or 1, more preferably 0.

The * in the formula (1) represents a bonding bond to a carboxyl-derived part (for example, an imino group) in a structural unit derived from a tetracarboxylic acid compound. In this specification, the so-called tetracarboxylic acid compound can be a compound having 4 carboxyl groups, a carboxylic acid halide, a carboxylic acid ester of the compound, and/or a carboxylic acid formed by dehydration and condensation of two adjacent carboxyl groups. As for the anhydride, the tetracarboxylic acid compound is preferably tetracarboxylic dianhydride from the viewpoint of ease of polymerization during synthesis.

[式(8)中，R^a 及n如式(1)中所定義]Provide a tetracarboxylic acid compound in which Y in the formula (a) is the structural unit (a1) represented by the formula (1), for example, when the tetracarboxylic acid compound is a tetracarboxylic dianhydride, it is derived from the formula (8) Represented: [化17]

[In formula (8), R ^a and n are as defined in formula (1)]

In the polyimide-based resin of the present invention, Y in the formula (a) is the amount of the structural unit (a1) represented by the formula (1) based on the amount contained in the polyamide-imide-based resin The total structural unit is preferably 2 to 45 mol%, more preferably 5 to 40%, further preferably 10 to 40 mol%, and particularly preferably 15 to 35 mol%. If the amount of the structural unit (a1) is more than the above lower limit, it is easy to increase the elastic modulus of the optical film. Moreover, if the amount of the structural unit (a1) is equal to or less than the above upper limit, it is easy to increase the total light transmittance of the optical film. Here, in this specification, the so-called total structural unit contained in the polyimide-based resin means the total monomer unit contained in the polyimide-based resin. Furthermore, the amount of structural unit (a1) and total structural unit contained in the polyimide-imide resin can be measured using ¹ H-NMR (nuclear magnetic resonance, nuclear magnetic resonance) or based on the addition of raw materials. Than calculated.

[＊表示鍵結鍵] 再者，式(1')相當於式(1)中之R^a 為氫原子且n為0之結構。Formula (1) is preferably represented by formula (1'): [化18]

[* indicates a bonding bond] Furthermore, formula (1') corresponds to ^a structure in which Ra is ^a hydrogen atom and n is 0 in formula (1).

The polyamide imine resin of the present invention has at least a structural unit (b) derived from a dicarboxylic acid compound in addition to the structural unit (a1) represented by the formula (1) in Y in the formula (a) , And the structural unit (c) derived from the diamine compound. The polyimide-based resin may have one type of structural unit (b), or may have two or more types of structural unit (b). In addition, the polyimide imine resin may have one type of structural unit (c), or may have two or more types of structural unit (c).

In the polyimide imine resin of the present invention, the amount of the structural unit (b) derived from the dicarboxylic acid compound is based on the total structural unit contained in the polyimide imine resin, and is preferably 5 to 70 mol%, more preferably 10-65%, still more preferably 20-60 mol%. If the amount of the structural unit (b) is more than the above lower limit, the solubility of the resin to the solvent is easily improved, and the stability of the varnish is easily improved. Moreover, if the amount of the structural unit (b) is less than or equal to the above upper limit, it is easy to increase the elastic modulus.

In the polyamide imine resin of the present invention, the amount of the structural unit (c) derived from the diamine compound is based on the structural unit (a) derived from the tetracarboxylic acid compound and the structure derived from the dicarboxylic acid compound When the total amount of the unit (b) is set to 100 mol%, it is preferably 95-105 mol%, more preferably 97-103 mol%, still more preferably 98-102 mol%, and particularly preferably 99 ~101 mole%. If the amount of the structural unit (c) is outside the above range, the molecular weight is unlikely to increase, and the stability of the varnish is likely to decrease.

[式(b)中，Z表示二價有機基， ＊表示鍵結鍵] 此處，式(b)中之＊係於本發明之聚醯胺醯亞胺系樹脂中，通常與和源自二羧酸化合物之結構單元相鄰之源自二胺化合物之結構單元(c)連結之鍵結鍵。結構單元(b)例如形成上述式(E)所表示之醯胺鍵。In the polyamide imine resin of the present invention, the structural unit (b) derived from the dicarboxylic acid compound is represented by the formula (b): [化19]

[In formula (b), Z represents a divalent organic group, * represents a bonding bond] Here, * in formula (b) is in the polyamide imide resin of the present invention, and is usually derived from The structural unit of the dicarboxylic acid compound is adjacent to the bonding bond derived from the structural unit (c) of the diamine compound. The structural unit (b) forms, for example, an amide bond represented by the above formula (E).

所表示之基之鍵結鍵中不相鄰之2個被取代為氫原子之二價有機基及碳數6以下之二價鏈式烴基，作為Z之雜環結構，可列舉具有噻吩環骨架之二價有機基。就容易抑制光學積層體之黃度(降低YI值)之觀點而言，較佳為式(20)～式(29)所表示之基之鍵結鍵中不相鄰之2個被取代為氫原子之二價有機基、及具有噻吩環骨架之二價有機基。於本發明之一實施形態中，聚醯胺醯亞胺系樹脂中所包含之結構單元(b)可包含1種有機基作為Z，亦可包含2種以上之有機基作為Z。Z in the formula (b) is a divalent organic group, preferably a hydrocarbon group with 1 to 8 carbons, a hydrocarbon group with 1 to 8 carbons substituted by fluorine, an alkoxy group with 1 to 6 carbons, or Fluorine-substituted alkoxy-substituted divalent organic groups with 4-40 carbons, more preferably hydrocarbon groups with 1-8 carbons, hydrocarbon groups with 1-8 carbons substituted by fluorine, An alkoxy group having 1 to 6 carbons, or a divalent organic group having 4 to 40 carbons and having a cyclic structure substituted by a fluorine-substituted alkoxy group with 1 to 6 carbons. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. As Z, the formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) and Formula (29): [化20]

Two non-adjacent divalent organic groups substituted with hydrogen atoms and a divalent chain hydrocarbon group with a carbon number of 6 or less in the bonding bond of the group represented. As the heterocyclic structure of Z, a thiophene ring skeleton can be mentioned The bivalent organic base. From the viewpoint of easily suppressing the yellowness of the optical laminate (decreasing the YI value), it is preferable that two non-adjacent bonding bonds of the groups represented by formulas (20) to (29) are substituted with hydrogen A divalent organic group of atoms and a divalent organic group having a thiophene ring skeleton. In one embodiment of the present invention, the structural unit (b) contained in the polyimide-based resin may include one type of organic group as Z, and may also include two or more types of organic groups as Z.

In formulas (20) to (29), * represents a bonding bond, W ¹ represents a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C (CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -Ar ³ -, -SO ₂ -, -CO-, -O-Ar ³ -O-, -Ar ³ -O-Ar ³ -,- _{^{Ar 3 -CH 2 -Ar 3 -,}} - Ar 3 -C (CH 3) 2 -Ar 3 - or -Ar ³ -SO ₂ -Ar ³ -. Ar ³ represents an arylene group having 6 to 20 carbon atoms in which a hydrogen atom can be substituted with a fluorine atom, and a phenylene group can be cited as a specific example. When Ar ³ in the presence of a plurality of situations, each Ar ³ may be the same, or different.

[式(20')～式(29')中，W¹ 及＊如式(20)～式(29)中所定義] 所表示之二價有機基。再者，式(20)～式(29)及式(20')～式(29')中之環上之氫原子可被取代為碳數1～8之烴基、經氟取代之碳數1～8之烴基、碳數1～6之烷氧基、經氟取代之碳數1～6之烷氧基。As the organic group of Z, it is more preferably formula (20'), formula (21'), formula (22'), formula (23'), formula (24'), formula (25'), formula (26') , Formula (27'), formula (28') and formula (29'): [化21]

[In formula (20') to formula (29'), W ¹ and * are as defined in formula (20) to formula (29)] A divalent organic group represented. Furthermore, the hydrogen atoms on the ring in formulas (20) to (29) and (20') to (29') can be substituted with hydrocarbon groups with 1 to 8 carbons, and 1 with fluorine substituted carbon atoms. ~8 hydrocarbon group, carbon number 1-6 alkoxy group, fluorine substituted alkoxy group with carbon number 1-6.

[式(d1)中，R²⁴ 相互獨立地表示氫原子、鹵素原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基， R²⁵ 表示R²⁴ 或-C(=O)-＊， ＊表示鍵結鍵] 所表示之源自羧酸之結構單元。When the polyimide imine-based resin has a structural unit represented by any of the above-mentioned formulas (20') to (29') in the formula (b) where Z is, it is easy to improve the composition of the varnish From the viewpoint of film properties and easy access to the uniformity of the obtained optical film, it is preferable that the polyimide-imide-based resin further has the following formula (d1) in addition to the structural unit: [化22]

[In formula (d1), R ²⁴ independently represents a hydrogen atom, a halogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, and R ²⁵ represents R ²⁴ or -C(=O)-*, * represents a bonding bond] The structural unit derived from carboxylic acid.

In R ^24, examples of an alkyl group having 1 to 6 carbon atoms, the carbon atoms of an alkoxy group having 1 to 6 carbon atoms and an aryl group of 6 to 12, include those of formula (1) in the R ^a are exemplified. As the structural unit (d1), specifically, structural units in which R ²⁴ and R ²⁵ are both hydrogen atoms (structural units derived from dicarboxylic acid compounds), R ²⁴ are both hydrogen atoms, and R ²⁵ represents -C( =O)-*The structural unit (the structural unit derived from the tricarboxylic acid compound), etc.

[式(b')中，Z表示二價有機基， R³¹ 及R³² 相互獨立地表示羥基、甲氧基、乙氧基、正丙氧基、異丙氧基、正丁氧基、第二丁氧基、第三丁氧基或氯原子] 所表示之化合物。The dicarboxylic acid compound providing the structural unit (b) is not particularly limited as long as it is a compound having two carbonyl groups. For example, the formula (b') can be cited: [化23]

[In formula (b'), Z represents a divalent organic group, and R ³¹ and R ³² independently represent a hydroxyl group, a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, and the first Dibutoxy, tertiary butoxy or chlorine atom].

[式(c)中，X表示二價有機基， R^c 相互獨立地表示氫原子或鍵結鍵， ＊表示鍵結鍵] 此處，式(c)所表示之結構單元(c)於本發明之聚醯胺醯亞胺系樹脂中，通常與源自四羧酸化合物之結構單元(a)或源自二羧酸化合物之結構單元(b)相鄰，且通常形成例如上述式(D)所表示之醯亞胺鍵及/或上述式(E)所表示之醯胺鍵。於結構單元(c)中，R^c 相互獨立地表示氫原子或鍵結鍵。於＊所表示之一個鍵結鍵鍵結於相鄰之源自四羧酸化合物之結構單元之情形時，根據式(D)亦清楚知道R^c 表示鍵結鍵，且鍵結於相鄰之源自四羧酸之結構單元。於結構單元(c)中，於＊所表示之一個鍵結鍵鍵結於相鄰之源自二羧酸化合物之結構單元之情形時，根據式(E)亦清楚知道R^c 表示氫原子。In the polyamide imine resin of the present invention, the structural unit (c) derived from the diamine compound is represented by the formula (c): [化24]

[In formula (c), X represents a divalent organic group, R ^c independently represents a hydrogen atom or a bonding bond, * represents a bonding bond] Here, the structural unit (c) represented by the formula (c) is in this In the polyamide imine resin of the invention, it is usually adjacent to the structural unit (a) derived from the tetracarboxylic acid compound or the structural unit (b) derived from the dicarboxylic acid compound, and usually forms such as the above-mentioned formula (D The amide bond represented by) and/or the amide bond represented by the above formula (E). In the structural unit (c), R ^c independently represents a hydrogen atom or a bonding bond. When a bonding bond represented by * is bonded to an adjacent structural unit derived from a tetracarboxylic acid compound, it is also clear from formula (D) that R ^c represents a bonding bond and is bonded to an adjacent A structural unit derived from tetracarboxylic acid. In the structural unit (c), when a bonding bond represented by * is bonded to an adjacent structural unit derived from a dicarboxylic acid compound, it is also clear from the formula (E) that R ^c represents a hydrogen atom.

X in the formula (c) represents a divalent organic group, preferably represents a divalent organic group having 4 to 40 carbons, more preferably represents a divalent organic group having 4 to 40 carbons having a cyclic structure. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. Regarding the above-mentioned organic group, the hydrogen atom in the organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. In this case, the carbon number of the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably 1-8. In one embodiment of the present invention, the structural unit (c) contained in the polyimide-based resin may include one type of divalent organic group as X, and may also include two or more types of divalent organic groups as X .

[式(c')中，X表示二價有機基] 所表示之化合物。The diamine compound providing the structural unit (c) is not particularly limited as long as it is a compound having two amine groups. For example, the formula (c') can be cited: [化25]

[In the formula (c'), X represents a divalent organic group].

[式(10)中，R^a 及n如式(1)中之R^a 及n所定義， X如式(c)中之X所定義， ＊表示鍵結鍵] 又，若例如式(b')所表示之二羧酸化合物與例如式(c')所表示之二胺化合物反應，則形成式(11)所表示之結構單元： [化27]

[式(11)中，Z如式(b)中之Z所定義， X如式(c)中之X所定義， ＊表示鍵結鍵]In the polyamide imine resin of the present invention, if the tetracarboxylic acid compound (such as the compound represented by the formula (8)) of the structural unit represented by the formula (1) is represented by the formula (c') The diamine compound reacts to form the structural unit represented by formula (10): [化26]

[In the formula (10), R ^a and n are as defined in formula R (1) in the ^a and n are as defined, in the X of formula (C) X defined * indicates bonding bond] Further, when, for example, of formula (b The dicarboxylic acid compound represented by') reacts with the diamine compound represented by formula (c') to form the structural unit represented by formula (11): [化27]

[In formula (11), Z is defined as Z in formula (b), X is defined as X in formula (c), and * represents a bonding bond]

[式(2)中，Z¹ 表示可具有取代基之二價芳香族基， ＊表示鍵結鍵] 所表示之結構單元(b1)作為源自二羧酸化合物之結構單元(b)。本發明之聚醯胺醯亞胺系樹脂通常具有複數個式(b)所表示之結構單元(b)。於本態樣中，只要複數個結構單元(b)之至少一部分為式(2)所表示之結構單元(b1)即可。於該態樣中，本發明之聚醯胺醯亞胺系樹脂可具有1種結構單元(b1)作為結構單元(b)，亦可具有2種以上之結構單元(b1)作為結構單元(b)，亦可具有結構單元(b1)以外之其他結構單元(b)。In a preferred aspect of the present invention, the polyimide-imide-based resin includes formula (2): [化28]

[In formula (2), Z ¹ represents a divalent aromatic group which may have a substituent, * represents a bonding bond] The structural unit (b1) represented as the structural unit (b) derived from the dicarboxylic acid compound. The polyamide imine resin of the present invention usually has a plurality of structural units (b) represented by the formula (b). In this aspect, as long as at least a part of a plurality of structural units (b) is a structural unit (b1) represented by formula (2). In this aspect, the polyimide imine resin of the present invention may have one type of structural unit (b1) as the structural unit (b), and may also have two or more types of structural units (b1) as the structural unit (b) ), may have other structural units (b) other than the structural unit (b1).

Z ¹ in the formula (2) represents a divalent aromatic group which may have a substituent. The divalent aromatic group is a group in which two hydrogen atoms of a monocyclic aromatic ring, a condensed polycyclic aromatic ring, or an assembling aromatic ring are replaced with bonding bonds. The divalent aromatic group may include an aromatic ring (monocyclic, condensed polycyclic, or collective ring) formed only by carbon atoms, or may include a heteroaromatic ring including atoms other than carbon atoms to form a ring. Examples of atoms other than carbon atoms include nitrogen atoms, sulfur atoms, and oxygen atoms. The total number of carbon atoms and atoms other than carbon atoms forming the aromatic ring is not particularly limited, but is preferably 5-18, more preferably 5-14, still more preferably 5-13, and particularly preferably 5-12 .

Examples of the monocyclic aromatic ring include benzene, furan, pyrrole, thiophene, pyridine, imidazole, pyrazole, azole, thiazole, imidazoline, and the like.

Examples of the condensed polycyclic aromatic ring include naphthalene, anthracene, phenanthrene, indole, benzothiazole, benzoxazole, and benzimidazole.

Examples of the assembling aromatic ring include a structure in which two or more monocyclic aromatic rings and/or condensed polycyclic aromatic rings are connected by a single bond. As an example, a monocyclic aromatic ring or An example of a condensed polycyclic aromatic ring where two or more of the rings described above are connected by a single bond, such as biphenyl, terphenyl, bitetraphenyl, binaphthyl, 1-phenylnaphthalene, 2-benzene Base naphthalene, bipyridine, etc.

From the standpoint of easily improving the elastic modulus and total light transmittance of the optical film, the divalent aromatic group that may have a substituent is preferably that the two hydrogen atoms of the aromatic hydrocarbon ring are substituted as a bonding bond group, More preferably, two hydrogen atoms of benzene, biphenyl, terphenyl or bitetraphenyl are substituted as a bonding bond group, and more preferably, two hydrogen atoms of benzene or biphenyl are substituted as a bonding bond group , It is especially preferred that the two hydrogen atoms of benzene are substituted into the bond group.

The divalent aromatic group represented by Z ¹ in formula (2) may have a substituent. Examples of the substituent include (i) alkyl groups having 1 to 12 carbons, (ii) alkoxy groups having 1 to 12 carbons, (iii) aryl groups having 6 to 12 carbons, and (iv) carbon At least one group in the group consisting of 6-12 aryloxy groups and (v) hydroxyl groups. Furthermore, the hydrogen atoms contained in the above substituents may be further independently substituted with halogen atoms, C1-C4 alkyl groups, C1-C4 alkoxy groups, hydroxyl groups, or carboxyl groups. The divalent aromatic group may have a hydrogen atom selected from the substituents (i) to (v) above and the hydrogen atoms contained in the substituents (i) to (v) above and are independently substituted with halogen atoms, At least one substituent in the group consisting of an alkyl group having 1 to 4 carbons, an alkoxy group having 1 to 4 carbons, a hydroxyl group, or a carboxyl group may not have a substituent. From the viewpoint of easy production of an optical film having a higher elastic modulus and total light transmittance, the divalent aromatic group represented by Z ¹ in formula (2) preferably does not have a substituent.

As (i) an alkyl group having 1 to 12 carbons, (ii) an alkoxy group having 1 to 12 carbons, and (iii) an aryl group having 6 to 12 carbons, there may be mentioned R ^a in the formula (1) The bases exemplified above, and the related better descriptions are also consistent with the above.

(Iv) The aryloxy group having 6 to 12 carbon atoms includes a phenoxy group, a tolyloxy group, a xylyloxy group, a naphthyloxy group, and a biphenoxy group. The carbon number of the aryloxy group having 6 to 12 carbon atoms is preferably 6 or 10 or 12. The above-mentioned aryloxy group having 6 to 12 carbons may be at least one hydrogen atom independently substituted with a halogen atom, an alkyl group having 1 to 4 carbons, an alkoxy group having 1 to 4 carbons, a hydroxyl group, or a carboxyl group The base. Examples of the halogen atom include the atoms described above. Here, when the aryloxy group having 6 to 12 carbon atoms is substituted with a substituent containing carbon atoms, the number of carbon atoms contained in the substituent is not included in the number of carbon atoms of the aryloxy group having 6 to 12 carbon atoms in.

In a preferred aspect of the present invention in which the polyamide imine-based resin of the present invention includes the structural unit (b1) represented by formula (2) as the structural unit (b) derived from a dicarboxylic acid compound, From the viewpoint of easily improving the total light transmittance and elastic modulus of the optical film, when the total of the structural units (b1) contained in the polyimide resin is set to 100 mol%, the formula (2 The ratio of the structural unit (b1) represented by) is preferably 70-100 mol%, more preferably 80-100 mol%, still more preferably 90-100 mol%, and may also be polyamide All the structural units (b) contained in the amine resin are structural units (b2). In addition, the content of the structural unit (b) and the structural unit (b1) can be measured using ¹ H-NMR or can also be calculated based on the addition ratio of the raw materials, for example.

[式(3)中，X¹ 表示可具有取代基之二價芳香族基， R^c 相互獨立地表示氫原子或鍵結鍵， ＊表示鍵結鍵] 所表示之結構單元(c1)作為源自二胺化合物之結構單元。本發明之聚醯胺醯亞胺系樹脂通常具有式(c)所表示之複數個結構單元(c)。於本態樣中，只要複數個結構單元(c)之至少一部分為式(3)所表示之結構單元(c1)即可。於該態樣中，本發明之聚醯胺醯亞胺系樹脂可具有1種結構單元(c1)作為結構單元(c)，亦可具有2種以上之結構單元(c1)作為結構單元(c)，亦可具有結構單元(c1)以外之其他結構單元(c)作為結構單元(c)。In a preferred aspect of the present invention, the polyimide imine resin of the present invention comprises formula (3): [化29]

[In formula (3), X ¹ represents a divalent aromatic group that may have a substituent, R ^c independently represents a hydrogen atom or a bonding bond, and * represents a bonding bond] The structural unit (c1) represented as the source From the structural unit of the diamine compound. The polyamide imine resin of the present invention usually has a plurality of structural units (c) represented by the formula (c). In this aspect, it is sufficient that at least a part of the plurality of structural units (c) is the structural unit (c1) represented by formula (3). In this aspect, the polyimide imine resin of the present invention may have one type of structural unit (c1) as the structural unit (c), and may also have two or more types of structural units (c1) as the structural unit (c) ), and may have other structural units (c) other than the structural unit (c1) as the structural unit (c).

X ¹ in formula (3) represents a divalent aromatic group which may have a substituent. The divalent aromatic group is a group where two hydrogen atoms of a monocyclic aromatic ring, a condensed polycyclic aromatic ring, or an assembling aromatic ring are replaced with a bonding bond. The divalent aromatic group may include an aromatic ring (monocyclic, condensed polycyclic, or collective ring) formed only by carbon atoms, or may include a heteroaromatic ring including atoms other than carbon atoms to form a ring. Examples of atoms other than carbon atoms include nitrogen atoms, sulfur atoms, and oxygen atoms. The total number of carbon atoms and atoms other than carbon atoms forming the aromatic ring is not particularly limited, but is preferably 5-18, more preferably 5-14, still more preferably 5-13, and particularly preferably 5-12 . As an example of a monocyclic aromatic ring, a condensed polycyclic aromatic ring, and an aggregate ring aromatic ring, the example described above about Z ¹ in formula (2) can be mentioned.

From the viewpoint of easily improving the elastic modulus and total light transmittance of the optical film, the divalent aromatic group which may have a substituent is preferably an aromatic hydrocarbon ring which may have a substituent. Two hydrogen atoms of the aromatic hydrocarbon ring are substituted as bonds The bonding group is more preferably substituted benzene, biphenyl, terphenyl or bitetraphenyl whose two hydrogen atoms are substituted as bonding groups, and more preferably substituted benzene or Two hydrogen atoms of biphenyl are substituted as a bonding bond group, and it is particularly preferable that two hydrogen atoms of biphenyl which may have a substituent are substituted as a bonding bond group.

The divalent aromatic group represented by X ¹ in formula (3) may have a substituent. Examples of substituents include alkyl groups having 1 to 12 carbons, alkoxy groups having 1 to 12 carbons, aryl groups having 6 to 12 carbons, and halogen groups, and hydrogen atoms contained in these groups are Substitution is a group of halogen atoms. Specific examples of alkyl groups having 1 to 12 carbons, alkoxy groups having 1 to 6 carbons, aryl groups having 6 to 12 carbons, and groups in which hydrogen atoms contained in these groups are substituted with halogen atoms can be Listed as the substituents that the divalent aromatic group represented by Z ¹ in formula (2) may have, (i) alkyl groups having 1 to 12 carbons, (ii) alkoxy groups having 1 to 12 carbons, (iii) The group described in the aryl group having 6 to 12 carbons. Examples of the halogen group include a fluoro group, a chloro group, a bromo group, or an iodo group.

As the substituent that the divalent aromatic group represented by X ¹ in the formula (3) may have, a halogen group or an alkyl group having 1 to 12 carbon atoms in which a hydrogen atom may be substituted with a halogen atom is more preferable It is methyl, fluoro, chloro or trifluoromethyl.

[式(4)中，R^b 相互獨立地表示碳數1～6之烷基、碳數6～12之芳基、或碳數1～6之烷氧基， R^b 中所包含之氫原子可相互獨立地被取代為鹵素原子， r相互獨立地表示1～4之整數， ＊表示鍵結鍵]In a preferred aspect of the present invention, X ¹ in formula (3) is preferred from the viewpoint of easily increasing the total light transmittance and elastic modulus of the optical film, and the viewpoint of easily increasing the stability of the varnish It is expressed by formula (4): [化30]

[In formula (4), R ^b independently represents an alkyl group having 1 to 6 carbons, an aryl group having 6 to 12 carbons, or an alkoxy group having 1 to 6 carbons, and the hydrogen atom contained in R ^b Can be substituted with halogen atoms independently of each other, r each independently represents an integer of 1 to 4, * represents a bonding bond]

R ^b in the formula (4) independently represents an alkyl group having 1 to 6 carbons, an aryl group having 6 to 12 carbons, or an alkoxy group having 1 to 6 carbons. The hydrogen atoms contained in R ^b also Can be substituted with halogen atoms independently of each other. Examples of alkyl groups having 1 to 6 carbons, aryl groups having 6 to 12 carbons, and alkoxy groups having 1 to 6 carbons include the divalent aromatic group represented by X ¹ in formula (3). The substituents are those exemplified above. R ^b in the formula (4) is preferably an alkyl group having 1 to 6 carbon atoms substituted by a halogen atom, more preferably a fluoroalkyl group having 1 to 6 carbon atoms, and still more preferably a perfluoroalkyl group having 1 to 6 carbon atoms The alkyl group is more preferably a perfluoroalkyl group having 1 to 4 carbon atoms, particularly preferably a trifluoromethyl group or a pentafluoroethyl group, and more preferably a trifluoromethyl group.

In the formula (4), r represents an integer of 1 to 4 independently of each other. From the viewpoint of easily improving the total light transmittance and elastic modulus of the optical film, it preferably represents 1 to 3, more preferably 1 to 2, More preferably, it is an integer of 1.

[式(4')中，R¹⁶ ～R²³ 相互獨立地表示氫原子或碳數1～6之氟烷基，其中，R¹⁶ ～R¹⁹ 之至少1個及R²⁰ ～R²³ 之至少1個表示碳數1～6之氟烷基， ＊表示鍵結鍵] 就容易提高光學膜之彈性模數及全光線透過率之觀點而言，式(4')中，更佳為至少R¹⁸ 及R²⁰ 表示碳數1～6之氟烷基，進而較佳為R¹⁸ 及R²⁰ 表示碳數1～6之氟烷基且R¹⁶ 、R¹⁷ 、R¹⁹ 、R²¹ 、R²² 及R²³ 表示氫原子。又，於上述態樣中，碳數1～6之氟烷基較佳為碳數1～6之全氟烷基，更佳為碳數1～4之全氟烷基，進而更佳為三氟甲基或五氟乙基，尤佳為三氟甲基。In a preferred aspect of the present invention, formula (4) is represented by formula (4'): [化31]

[In formula (4'), R ¹⁶ to R ²³ independently represent a hydrogen atom or a fluoroalkyl group having 1 to 6 carbon atoms, wherein at least one of R ¹⁶ to R ¹⁹ and at least one of R ²⁰ to R ²³ Each represents a fluoroalkyl group having 1 to 6 carbon atoms, * represents a bonding bond] From the viewpoint of easily improving the elastic modulus and total light transmittance of the optical film, in formula (4'), it is more preferably at least R ¹⁸ And R ²⁰ represents a fluoroalkyl group having 1 to 6 carbons, more preferably R ¹⁸ and R ²⁰ represent a fluoroalkyl group having 1 to 6 carbons, and R ¹⁶ , R ¹⁷ , R ¹⁹ , R ²¹ , R ²² and R ²³ represents a hydrogen atom. In addition, in the above aspect, the fluoroalkyl group having 1 to 6 carbon atoms is preferably a perfluoroalkyl group having 1 to 6 carbon atoms, more preferably a perfluoroalkyl group having 1 to 4 carbon atoms, and still more preferably trifluoroalkyl groups. Fluoromethyl or pentafluoroethyl, particularly preferably trifluoromethyl.

[式(4")中，＊表示鍵結鍵] 再者，式(4")相當於式(4')中之R¹⁸ 及R²⁰ 表示三氟甲基且R¹⁶ 、R¹⁷ 、R¹⁹ 、R²¹ 、R²² 及R²³ 表示氫原子之式。In a preferred aspect of the present invention, the formula (4') is represented by the formula (4"): [化32]

[In formula (4"), * represents a bonding bond] Furthermore, formula (4") corresponds to formula (4') where R ¹⁸ and R ²⁰ represent trifluoromethyl and R ¹⁶ , R ¹⁷ , R ¹⁹ , R ²¹ , R ²² and R ²³ represent the formula of a hydrogen atom.

In a preferred aspect of the present invention in which the polyimide imine-based resin of the present invention includes the structural unit (c1) represented by the formula (3) as the structural unit (c) derived from a diamine compound, it is easy to From the viewpoint of improving the total light transmittance and elastic modulus of the optical film, and easily improving the stability of the varnish, the total of the structural units (c) contained in the polyimide resin is set to 100 mol %, the ratio of the structural unit (c1) represented by formula (3) is preferably 50-98 mol%, more preferably 60-95 mol%, and still more preferably 70-94 mol%. It can be that part of the structural unit (c) contained in the polyimide-imide resin is the structural unit (c1), or all of the structural unit (c) is the structural unit (c1), which can easily improve the optical film From the viewpoints of total light transmittance and elastic modulus and easy improvement of the stability of the varnish, it is preferable that a part of the structural unit (c) contained in the polyimide-based resin is the structural unit (c1). In addition, the content of the structural unit (c) and the structural unit (c1) can be measured using ¹ H-NMR, or can also be calculated based on the addition ratio of the raw materials.

From the viewpoints of easily improving the total light transmittance and elastic modulus of the optical film, and easily improving the stability of the varnish, the polyimide-imide-based resin of the present invention preferably includes the Y-based compound in formula (a) The structural unit (a1) represented by the formula (1) as a structural unit derived from a tetracarboxylic acid compound includes the structural unit (b1) represented by the formula (2) as a structural unit derived from a dicarboxylic acid compound, and includes the formula (3) The structural unit (c1) represented as a structural unit derived from a diamine compound.

[式(5)中，Ar¹ 相互獨立地表示可具有取代基之二價芳香族基， V表示-O-、二苯基亞甲基、碳數1～12之直鏈狀、支鏈狀或脂環式之二價烴基、-SO₂ -、-S-、-CO-或-N(R¹² )-，此處，該烴基中所包含之氫原子可相互獨立地被取代為鹵素原子， R¹² 表示氫原子、或可經鹵素原子取代之碳數1～12之烷基， m表示1～3之整數，其中，於m為2或3之情形時所存在之複數個V可相互相同，亦可不同， ＊表示鍵結鍵] 所表示之結構單元作為源自二羧酸化合物之結構單元、及/或包含式(c)中之X係由式(5)所表示之結構單元作為源自二胺化合物之結構單元、及/或進而包含式(a)中之Y係由式(6)： [化34]

[式(6)中，Ar² 相互獨立地表示可具有取代基之三價芳香族基， s表示0～2之整數， Ar¹ 、V及＊如式(5)中之Ar¹ 、V及＊所定義，其中，於s為2之情形時所存在之複數個V及Ar¹ 可分別相互相同，亦可不同] 所表示之結構單元作為源自四羧酸化合物之結構單元。再者，於本說明書中，將可作為源自二羧酸化合物之結構單元而包含之式(b)中之Z係由式(5)所表示之結構單元亦稱為「結構單元(b2)」，將可作為源自二胺化合物之結構單元而包含之式(c)中之X係由式(5)所表示之結構單元亦稱為「結構單元(c2)」，將可作為源自四羧酸化合物之結構單元而包含之式(a)中之Y係由式(6)所表示之結構單元亦稱為「結構單元(a2)」。本發明之聚醯胺醯亞胺系樹脂至少具有上述結構單元(a1)、結構單元(b)及結構單元(c)，於較佳之一態樣中，包含結構單元(b2)作為結構單元(b)、包含結構單元(c2)作為結構單元(c)、及/或除包含結構單元(a1)以外亦進而包含結構單元(a2)作為結構單元(a)。於該態樣中，除式(1)所表示之結構單元以外，式(5)所表示之結構單元、及/或式(6)所表示之結構單元亦包含於本發明之聚醯胺醯亞胺系樹脂中。再者，於聚醯胺醯亞胺系樹脂包含結構單元(b2)作為結構單元(b)之情形時，該樹脂可包含結構單元(b1)，亦可不包含結構單元(b1)。又，於聚醯胺醯亞胺系樹脂包含結構單元(c2)作為結構單元(c)之情形時，該樹脂可包含結構單元(c1)，亦可不包含結構單元(c1)。In a preferred aspect of the present invention, the polyimide-imide-based resin includes the Z in the formula (b) is derived from the formula (5): [化33]

[In formula (5), Ar ¹ independently represents a divalent aromatic group that may have a substituent, and V represents -O-, diphenylmethylene, linear or branched chain with 1 to 12 carbon atoms Or alicyclic divalent hydrocarbon group, -SO ₂ -, -S-, -CO- or -N(R ¹² )-, where the hydrogen atoms contained in the hydrocarbon group can be independently substituted with halogen atoms , R ¹² represents a hydrogen atom or an alkyl group with 1 to 12 carbon atoms that can be substituted by a halogen atom, m represents an integer of 1 to 3, wherein when m is 2 or 3, multiple Vs may be mutually The same or different, ＊represents a bonding bond] as a structural unit derived from a dicarboxylic acid compound, and/or includes a structural unit represented by formula (5) where X in formula (c) is As a structural unit derived from a diamine compound, and/or further comprising Y in formula (a) is derived from formula (6): [化34]

[In formula (6), Ar ² independently represents a trivalent aromatic group which may have a substituent, s represents an integer of 0-2, Ar ¹ , V and * are as in the formula (5) Ar ¹ , V and *Defined, where the plurality of V and Ar ¹ existing when s is 2 may be the same or different from each other] The structural unit represented is as the structural unit derived from the tetracarboxylic acid compound. Furthermore, in this specification, the structural unit represented by formula (5) in formula (b) that can be included as a structural unit derived from a dicarboxylic acid compound is also referred to as "structural unit (b2) ", the structural unit represented by formula (5) in formula (c) that can be included as a structural unit derived from a diamine compound is also called "structural unit (c2)", which can be used as a structural unit derived from The structural unit of the tetracarboxylic acid compound and the Y in the formula (a) included in the structural unit represented by the formula (6) is also called "structural unit (a2)". The polyamide imine resin of the present invention has at least the above-mentioned structural unit (a1), structural unit (b) and structural unit (c), and in a preferred aspect, includes structural unit (b2) as structural unit ( b), including structural unit (c2) as structural unit (c), and/or including structural unit (a2) as structural unit (a) in addition to structural unit (a1). In this aspect, in addition to the structural unit represented by the formula (1), the structural unit represented by the formula (5) and/or the structural unit represented by the formula (6) are also included in the polyamide resin of the present invention In imine resins. Furthermore, when the polyimide imine-based resin includes the structural unit (b2) as the structural unit (b), the resin may include the structural unit (b1), or may not include the structural unit (b1). In addition, when the polyimide-based resin includes the structural unit (c2) as the structural unit (c), the resin may include the structural unit (c1), or may not include the structural unit (c1).

Here, the structural unit represented by the formula (5) and the structural unit represented by the formula (6) include the linear, branched, or linear, branched, or C1-O-, diphenylmethylene groups The alicyclic divalent hydrocarbon group, -SO ₂ -, -S-, -CO- or -N(R ¹² )- is the divalent linking group V, so it has a relatively flexible structure. When the polyimide-based resin further includes a structure with higher flexibility as described above, it is easy to reduce the intermolecular interaction of the polyimide-based resin. As a result, it is easy to increase the elastic modulus of the optical film containing the polyimide-based resin. In addition, it is easy to improve the stability of the varnish of the polyimide resin.

The polyamide imine resin of the present invention has the Z in the formula (b) and the structural unit (b2) derived from the dicarboxylic acid compound represented by the formula (5), and the X in the formula (c) The structural unit (c2) derived from the diamine compound represented by the formula (5), and/or the Y in the formula (a) is the structural unit (a2) derived from the tetracarboxylic acid compound represented by the formula (6) In the case of ), the total amount of structural unit (b2), structural unit (c2) and structural unit (a2) is based on the total structural unit contained in the polyimide-based resin, preferably 1-25 mol %, more preferably 2-20 mol%, still more preferably 3-15 mol%. If the total amount is within the above range, the stability of the varnish is easily improved, and the processability and total light transmittance of the optical film are easily improved. Furthermore, in this aspect, the so-called total amount of structural unit (b2), structural unit (c2) and structural unit (a2) does not mean that all polyimide-based resins have these three structural units The polyimide imine resin only needs to have at least one structural unit selected from the group consisting of structural unit (b2), structural unit (c2), and structural unit (a2).

Furthermore, when the polyimide-based resin of the present invention has a structural unit (b2), a structural unit (c2), and/or a structural unit (a2), the structural unit (b2) and the structural unit (c2) And the total molar amount of the structural unit (a2) relative to 1 molar of the structural unit (a1) represented by the formula (1) in the formula (a) contained in the polyimide imine-based resin, It is preferably 0.01 to 1.0, more preferably 0.02 to 0.50, and still more preferably 0.05 to 0.20. If the total molar amount is more than the above lower limit, it is easy to improve the solubility to varnish. Moreover, if the total molar amount is equal to or less than the above upper limit, it is easy to increase the elastic modulus. Furthermore, in this aspect, the above-mentioned total molar amount does not mean that the polyimide-based resin all has these three types of structural units.

Ar ^{1 in} formula (5) and formula (6) represents a divalent aromatic group which may have a substituent. The divalent aromatic group is a group where two hydrogen atoms of a monocyclic aromatic ring, a condensed polycyclic aromatic ring, or an assembling aromatic ring are replaced with a bonding bond. The divalent aromatic group may include an aromatic ring (monocyclic, condensed polycyclic, or collective ring) formed only by carbon atoms, or may include a heteroaromatic ring including atoms other than carbon atoms to form a ring. Examples of atoms other than carbon atoms include nitrogen atoms, sulfur atoms, and oxygen atoms. The total number of carbon atoms and atoms other than carbon atoms forming the aromatic ring is not particularly limited, but is preferably 5-18, more preferably 5-14, still more preferably 5-13, and particularly preferably 5-12 . As an example of a monocyclic aromatic ring, a condensed polycyclic aromatic ring, and an aggregate ring aromatic ring, the example described above about Z ¹ in formula (2) can be mentioned.

From the standpoint of easily improving the elastic modulus and total light transmittance of the optical film, the divalent aromatic group that may have a substituent is preferably that the two hydrogen atoms of the aromatic hydrocarbon ring are substituted as a bonding bond group, More preferably, two hydrogen atoms of benzene, biphenyl, terphenyl or bitetraphenyl are substituted as a bonding bond group, and more preferably, two hydrogen atoms of benzene or biphenyl are substituted as a bonding bond group .

The divalent aromatic group represented by Ar ¹ in formula (5) and formula (6) may have a substituent. Examples of the substituent include: (i) alkyl having 1 to 12 carbons, (ii) alkoxy having 1 to 12 carbons, (iii) aryl having 6 to 12 carbons, and (iv) carbon number 6-12 aryloxy group, (v) carbonyl group with 1-12 carbons, (vi) oxycarbonyl group with 1-12 carbons, or (vii) halogen group. In addition, the hydrogen atoms contained in the above substituents may be further independently substituted with halogen atoms, C1-C4 alkyl groups, C1-C4 alkoxy groups, hydroxyl groups, or carboxyl groups. The divalent aromatic group may have at least one of the above-mentioned (i) to (vii) substituents, and/or the hydrogen atoms contained in the above-mentioned (i) to (vii) substituents may be substituted independently of each other with A halogen atom, an alkyl group having 1 to 4 carbons, an alkoxy group having 1 to 4 carbons, a hydroxyl group, or a carboxyl group may not have a substituent. From the viewpoint of manufacturing an optical film having a relatively high elastic modulus, it is preferable that the divalent aromatic group represented by Ar ¹ in formula (5) and formula (6) does not have a substituent.

As (i) C1-C12 alkyl group, (ii) C1-C12 alkoxy group, (iii) C6-C12 aryl group and (iv) C6-C12 aryloxy group Examples include the groups exemplified above regarding the substituents that the divalent aromatic group represented by Z ¹ in formula (2) may have.

(v) The carbonyl group having 1 to 12 carbons is a group represented by *-CO-R ^d or *-R ^e -CO-R ^d . Examples of R ^d include the groups described for (i) alkyl groups having 1 to 12 carbons, and examples of R ^e include at least one hydrogen of the groups described for (i) alkyl groups having 1 to 12 carbons. The atom is substituted with a divalent alkylene group having 1 to 12 carbon atoms. The aforementioned carbonyl group with 1 to 12 carbons may be a group in which at least one hydrogen atom is independently substituted with a halogen atom, an alkyl group with 1 to 4 carbons, an alkoxy group with 1 to 4 carbons, a hydroxyl group, or a carboxyl group. . Examples of the halogen atom include the atoms described above. Here, when the carbonyl group having 1 to 12 carbon atoms is substituted with a substituent containing carbon atoms, the number of carbon atoms contained in the substituent is not included in the number of carbon atoms in the carbonyl group having 1 to 12 carbon atoms.

(vi) The oxycarbonyl group with 1 to 12 carbons is composed of *-CO-OR ^d , *-R ^e -CO-OR ^d , *-O-CO-R ^d , or -R ^e -O-CO-R ^d The base expressed. Examples of R ^d include the groups described for (i) alkyl groups having 1 to 12 carbons, and examples of R ^e include at least one hydrogen of the groups described for (i) alkyl groups having 1 to 12 carbons. The atom is substituted with a divalent alkylene group having 1 to 12 carbon atoms. The above-mentioned oxycarbonyl group having 1 to 12 carbons may be one of at least one hydrogen atom independently substituted with a halogen atom, an alkyl group having 1 to 4 carbons, an alkoxy group having 1 to 4 carbons, a hydroxyl group, or a carboxyl group. base. Examples of the halogen atom include the atoms described above. Here, when the oxycarbonyl group having 1 to 12 carbon atoms is substituted with a substituent containing carbon atoms, the number of carbon atoms contained in the substituent is not included in the carbon number of the oxycarbonyl group having 1 to 12 carbon atoms.

(Vii) The halogen group includes a fluoro group, a chloro group, a bromo group, or an iodo group.

Ar ² in formula (6) represents a trivalent aromatic group which may have a substituent. The trivalent aromatic group is a monocyclic aromatic ring, a condensed polycyclic aromatic ring, or a condensed polycyclic aromatic ring, and three hydrogen atoms are substituted into a bonding group. The trivalent aromatic group may include an aromatic ring (monocyclic, condensed polycyclic or collective ring) formed only by carbon atoms, and may include a heteroaromatic ring including atoms other than carbon atoms to form a ring. Examples of atoms other than carbon atoms include nitrogen atoms, sulfur atoms, and oxygen atoms. The total number of carbon atoms and atoms other than carbon atoms forming the aromatic ring is not particularly limited, but is preferably 5-18, more preferably 5-14, still more preferably 5-13, and particularly preferably 5-12 . As the monocyclic aromatic ring, the condensed polycyclic aromatic ring, or the condensed ring aromatic ring in the trivalent aromatic group, those described with respect to Ar ¹ can be mentioned. Examples of the substituents that the trivalent aromatic group may have include the substituents described for Ar ¹ above, and the preferable descriptions for Ar ¹ are similarly applicable to Ar ² .

From the viewpoint of easy improvement of the elastic modulus and total light transmittance of the optical film, the trivalent aromatic group that may have a substituent is preferably that the three hydrogen atoms of the aromatic hydrocarbon ring are substituted as a bonding bond group, It is more preferable that 3 hydrogen atoms of benzene, biphenyl, terphenyl or bitetraphenyl are substituted as a bonding bond group, and more preferably, 3 hydrogen atoms of benzene or biphenyl are substituted as a bonding bond group .

In the case where m in formula (5) is 1 or more and/or when s in formula (6) is 2, the plurality of Ar ¹ may be the same or different. In addition, the plurality of Ar ² in the formula (6) may be the same or different from each other.

M in formula (5) represents an integer of 1-3. From the viewpoint of improving the modulus of elasticity and ensuring the solubility to the varnish, 1 or 2 is preferable, and 1 is more preferable. The * in formula (5) represents a bonding bond.

In the formula (6), s represents an integer of 0-2. From the viewpoint of ensuring the solubility to the varnish and ensuring a higher transmittance, it is preferably 0 or 1, and more preferably 0. The * in formula (6) represents a bonding bond.

V in formula (5) and formula (6) represents -O-, diphenylmethylene, a linear, branched or alicyclic divalent hydrocarbon group with 1 to 12 carbon atoms, -SO _2- , -S-, -CO- or -N(R ¹² )-, where the hydrogen atoms contained in the hydrocarbon group can be independently substituted with halogen atoms, and R ¹² represents a hydrogen atom or can be substituted with a halogen atom The alkyl group with 1-12 carbons. The carbon number of 1 to 12 linear, branched or alicyclic alkyl group of, include an alkyl group on the carbon number of R ^a formula (1) of the 1 to 12 described in the.

Regarding V in formula (5) and formula (6), as a linear, branched, or alicyclic divalent hydrocarbon group having 1 to 12 carbons, there can be exemplified linear and branched hydrocarbon groups having 1 to 12 carbons. At least one hydrogen atom of the chain or alicyclic alkyl group is substituted with a bonding group. Furthermore, examples of the linear, branched, or alicyclic alkyl group having 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, and second Butyl, tertiary butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2-ethylpropyl, n-hexyl, n-heptyl, n-octyl, tertiary octyl, n Nonyl, n-decyl, cyclopentyl, cyclohexyl, etc. The divalent hydrocarbon group having 1 to 12 carbon atoms may also be a linear alkylene group, a branched chain alkylene group, or an alicyclic alkylene group containing an alicyclic hydrocarbon structure. The carbon number of the divalent hydrocarbon group having 1 to 12 carbons is preferably 1 to 6, more preferably 1 to 4, and still more preferably 1 to 3. The above-mentioned divalent hydrocarbon group having 1 to 12 carbon atoms may be a group in which at least one hydrogen atom is independently substituted with a halogen atom. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

In formula (5) and formula (6), when there are plural Ar ¹ , Ar ² and/or V, they may be the same as each other or different, but it is easy to synthesize polyimide imine From the viewpoint of the resin, it is preferable that the plurality of Ar ^{1 present} are the same as each other, the plurality of Ar ^{2 present} are the same as each other, and/or the plurality of V present are the same as each other.

[式(7)中，R¹ 相互獨立地表示氫原子、碳數1～12之烷基、碳數1～12之烷氧基或碳數6～12之芳基，R¹ 中所包含之氫原子可相互獨立地被取代為鹵素原子， R^＊ 表示R¹ 或鍵結鍵， ＊表示鍵結鍵， V表示-O-、二苯基亞甲基、碳數1～12之直鏈狀、支鏈狀或脂環式之二價烴基、-SO₂ -、-S-、-CO-或-N(R¹² )-，此處，該烴基中所包含之氫原子可相互獨立地被取代為鹵素原子，R¹² 表示氫原子、或可經鹵素原子取代之碳數1～12之烷基] 再者，於式(5)係由式(7)所表示之情形時，式(7)中之鍵結鍵變成2個，故而R^＊ 表示R¹ 。又，於式(6)係由式(7)所表示之情形時，式(7)中之鍵結鍵變成4個，故而R^＊ 表示鍵結鍵。又，關於式(7)中之R¹ ，與式(5)中之Ar¹ 及式(6)中之Ar² 可具有之取代基相關之記載同樣地符合，較佳之記載亦同樣地符合。又，關於式(7)中之V，與式(5)及式(6)中之V相關之記載亦同樣地符合。In a preferred aspect of the present invention, formula (5) and formula (6) are represented by formula (7): [化35]

[In formula (7), R ¹ independently represents a hydrogen atom, a C 1-12 alkyl group, a C 1-12 alkoxy group, or a C 6-12 aryl group, which is contained in R ¹ Hydrogen atoms can be independently substituted with halogen atoms, R ^＊ represents R ¹ or bonding bond, ＊represents bonding bond, V represents -O-, diphenylmethylene, linear chain with carbon number 1-12 , Branched or alicyclic divalent hydrocarbon group, -SO ₂ -, -S-, -CO- or -N(R ¹² )-, where the hydrogen atoms contained in the hydrocarbon group can be mutually independently Is substituted with a halogen atom, R ¹² represents a hydrogen atom, or an alkyl group with 1 to 12 carbon atoms which can be substituted by a halogen atom] Furthermore, when the formula (5) is represented by the formula (7), the formula (7) The bonding bond in) becomes two, so R ^* means R ¹ . Furthermore, when the formula (6) is represented by the formula (7), the bonding bond in the formula (7) becomes 4, so R ^* represents a bonding bond. Further, in the middle of about the formula (7) R ^1, and the formula (5) in the Ar ¹ and the formula (6) Ar ² may have the substituent group associated the described similarly meet, preferably the described equally conform. In addition, regarding V in formula (7), the descriptions related to V in formulas (5) and (6) also conform in the same way.

In a preferred aspect of the present invention, the polyimide imine resin contains the structural unit (c2) represented by the formula (5) or the formula (7) in the formula (c) as derived from In the case of the structural unit of the diamine compound and/or further include the structural unit (a2) represented by the formula (6) or the formula (7) in the formula (a) as the structural unit derived from the tetracarboxylic acid compound In this case, from the viewpoints of the elastic modulus, total light transmittance, surface hardness and bending resistance of the optical film and the stability of the varnish, in formula (5), formula (6) and formula (7) The V preferably represents -O-, diphenylmethylene, a linear, branched or alicyclic divalent hydrocarbon group with 1-12 carbons or a divalent hydrocarbon group with 1-12 carbons The group in which the contained hydrogen atom is substituted with a halogen atom is more preferably a group in which a hydrogen atom contained in a divalent hydrocarbon group with 1 to 12 carbons or a divalent hydrocarbon group with 1 to 12 carbons is substituted with a halogen atom.

In this aspect, V in formula (5), formula (6) and formula (7) is more preferably at least one of linear, branched or alicyclic alkylenes having 1 to 12 carbon atoms One hydrogen atom is substituted with a halogen atom (preferably a fluorine atom) (preferably a fluoroalkylene group with 1 to 12 carbons), and more preferably a straight chain or branched chain with 1 to 12 carbons All hydrogen atoms of the alicyclic or alicyclic alkylene groups are substituted with halogen atoms (preferably fluorine atoms) (preferably perfluoroalkylene groups with 1 to 12 carbon atoms, especially ditrifluoromethyl) Methylene).

[式(7')中，R^＊ 表示氫原子或鍵結鍵， ＊表示鍵結鍵] 或式(7")： [化37]

[式(7")中，＊表示鍵結鍵] 所表示。於聚醯胺醯亞胺系樹脂進而包含式(a)中之Y係由式(6)所表示之結構單元(a2)作為源自四羧酸化合物之結構單元之情形時及包含式(c)中之X係由式(5)所表示之結構單元(c2)作為源自二胺化合物之結構單元(c)之情形時，較佳為式(5)係由式(7)所表示，更佳為式(7)係由式(7')所表示。又，於聚醯胺醯亞胺系樹脂包含式(b)中之Z係由式(5)所表示之結構單元(b2)作為源自二羧酸化合物之結構單元之情形時，較佳為式(5)係由式(7)所表示，更佳為式(7)係由式(7")所表示。In this aspect, formula (7) is preferably derived from formula (7'): [化36]

[In formula (7'), R ^* represents a hydrogen atom or a bonding bond, * represents a bonding bond] or formula (7"): [化37]

[In formula (7"), * represents a bonding bond]. The polyimide imine resin further includes the Y in the formula (a) is represented by the structural unit (a2) represented by the formula (6) as In the case of a structural unit derived from a tetracarboxylic acid compound and when the structural unit (c2) represented by formula (5) is included in the formula (c) as the structural unit (c) derived from a diamine compound Preferably, the formula (5) is represented by the formula (7), more preferably the formula (7) is represented by the formula (7'). In addition, the polyimide-based resin includes the formula (b) In the case where Z is the structural unit (b2) represented by the formula (5) as the structural unit derived from the dicarboxylic acid compound, it is preferred that the formula (5) is represented by the formula (7), more preferably The formula (7) is represented by the formula (7").

In a preferred aspect of the present invention, the polyimide-imide resin has the above-mentioned structural unit (a1), structural unit (b) and structural unit (c), and further has at least the formula (a) Y is a structural unit (a2) derived from a tetracarboxylic acid compound represented by formula (6). In this case, the amount of structural unit (a2) is based on the total structural units contained in the polyimide-based resin, preferably 1-25 mol%, more preferably 2-20 mol%, and then Preferably it is 3-15 mol%. If the amount of the structural unit (a2) is within the above range, it is easy to improve the stability of the varnish, and it is easy to improve the processability and total light transmittance of the optical film.

In another preferred aspect of the present invention, in addition to the above-mentioned structural unit (a1) and structural unit (b), the polyimide imine-based resin also has at least the X in the formula (c) by the formula (5) The structural unit (c2) represented as a structural unit (c) derived from a diamine compound. Furthermore, in this aspect, as long as at least some of the structural units (c) existing in the polyimide-based resin are structural units (c2). In the case where the polyimide-based resin has at least the above-mentioned structural unit (a1), structural unit (b) and structural unit (c2), the amount of the structural unit (c2) is based on the polyimide-imide resin The total structural unit contained is preferably 1-25 mol%, more preferably 2-20 mol%, and still more preferably 3-15 mol%. If the amount of the structural unit (c2) is within the above range, it is easy to improve the stability of the varnish, and it is easy to improve the processability and total light transmittance of the optical film.

In a preferred aspect of the present invention, the polyimide imine-based resin contains the structural unit (b2) represented by the formula (5) or the formula (7) in the formula (b) as derived from In the case of the structural unit of the dicarboxylic acid compound, in terms of the elastic modulus, total light transmittance, surface hardness, and bending resistance of the optical film, and the stability of the varnish, formulas (5) and (7) V in) preferably represents -O-, diphenylmethylene, a linear, branched or alicyclic divalent hydrocarbon group with 1 to 12 carbons, or a divalent hydrocarbon group with 1 to 12 carbons The hydrogen atom contained in the hydrocarbon group is substituted with a halogen atom, and more preferably represents -O-.

[式(9)中，R⁴ ～R¹¹ 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基、或碳數6～12之芳基，R⁴ ～R¹¹ 中所包含之氫原子可相互獨立地被取代為鹵素原子， m為1～4之整數， 式(5)及式(7)中之V表示鍵結鍵]In this aspect, formula (5) is preferably represented by formula (9): [化38]

[In formula (9), R ⁴ to R ¹¹ independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, R ⁴ The hydrogen atoms contained in ~R ¹¹ can be independently substituted with halogen atoms, m is an integer of 1 to 4, and V in formula (5) and formula (7) represents a bonding bond]

R ⁴ to R ¹¹ in formula (9) independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, and R ⁴ to The hydrogen atoms contained in R ¹¹ may be independently substituted with halogen atoms. Examples of alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, second butyl, tertiary butyl, n-pentyl, and 2-methyl Butyl, 3-methylbutyl, 2-ethylpropyl, n-hexyl, etc. Examples of alkoxy groups having 1 to 6 carbon atoms include: methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tertiary butoxy, and pentoxy , Hexyloxy, cyclohexyloxy, etc. Examples of aryl groups having 6 to 12 carbon atoms include phenyl, tolyl, xylyl, naphthyl, biphenyl and the like. From the viewpoint of the surface hardness and flexibility of the optical film, R ⁴ to R ¹¹ independently of each other preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably represent a hydrogen atom or a carbon number of 1 to 3 The alkyl group further preferably represents a hydrogen atom. Here, the hydrogen atoms contained in R ⁴ to R ¹¹ may be substituted with halogen atoms independently of each other. As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned.

In the formula (9), m is an integer of 1 to 4. If m is within this range, the bending resistance and elastic modulus of the optical film are likely to become good. Furthermore, m in formula (9) is preferably an integer in the range of 1 to 3, more preferably 1 to 2, and still more preferably 1. If m is within this range, it is easy to improve the bending resistance and elastic modulus of the optical film. When the polyamide imine-based resin of the present invention has the Z in formula (b) as the structural unit (b) derived from the dicarboxylic acid compound as the structural unit represented by formula (9), the polyamide The amine imine-based resin may have one or two or more structural units represented by the formula (9) as Z in the formula (b).

於該情形時，容易提高光學膜之表面硬度及耐彎曲性、容易降低黃度。In this aspect, formula (9) is preferably represented by formula (7"): [化39]

In this case, it is easy to increase the surface hardness and bending resistance of the optical film, and it is easy to reduce the yellowness.

The polyimide imine resin of the present invention includes the structural unit (b2) represented by formula (5), formula (7), formula (9) or formula (7") in formula (b) as In the case of structural unit (b) derived from a dicarboxylic acid compound, the ratio of structural unit (b2) when the total amount of structural units contained in the polyimide-imide resin is set to 100 mol% It is preferably 1 mol% or more, more preferably 2 mol% or more, further preferably 3 mol% or more, particularly preferably 4 mol% or more, preferably 45 mol% or less, and more preferably 35 mol% Mole% or less, more preferably 25 mole% or less, and particularly preferably 15 mole% or less. If the ratio of the structural unit (b2) is more than the above lower limit, the surface hardness and bending resistance of the optical film are easily improved. In addition, if the ratio is less than the above upper limit, it is easy to suppress the increase in the viscosity of the resin-containing varnish and improve the processability of the film. Furthermore, the content of these structural units can be measured, for example, using ¹ H-NMR or based on raw materials. Calculated by adding ratio.

In a preferred embodiment of the present invention, the polyamide imide resin of the present invention includes formula (b). Z in formula (b) is determined by formula (5), formula (7), formula (9) or formula (7). When the structural unit (b2) represented by ") is used as the structural unit (b) derived from a dicarboxylic acid compound, the structural unit (b) is preferably 5 mol% or more, more preferably 8 Mole% or more, more preferably 10 mol% or more, and particularly preferably 12 mol% or more are the structural unit (b2). If the amount of the structural unit (b2) is within the above range, the surface hardness of the optical film will be easily increased And it is easy to improve the bending resistance and the modulus of elasticity. In addition, it is preferable that the structural unit (b) derived from the dicarboxylic acid compound possessed by the polyamide imide resin of the present invention is preferably 90 mol % Or less, more preferably 70 mol% or less, more preferably 50 mol% or less, and particularly preferably 30 mol% or less, is the structural unit (b3). If the amount of the structural unit (b2) is in the above range, then It is easy to suppress the increase in the viscosity of the resin-containing varnish and improve the processability of the film. It is preferable that the polyamide imide resin of the present invention contains the above-mentioned amount of the structural unit (b2) as the structural unit (b) derived from the dicarboxylic acid compound ), and has the above structural unit (b1) as the other structural unit (b).

The polyimide imine resin of the present invention contains at least the structural unit (b) represented by the formula (b) in addition to the Y in the formula (a) being the structural unit (a1) represented by the formula (1) And the structural unit (c) represented by formula (c). Here, from the viewpoints that it is easy to improve the stability of the varnish and the total light transmittance, elastic modulus, surface hardness and bending resistance of the obtained optical film, it is preferably the polyamide resin of the present invention. In addition to the structural unit (a1) represented by formula (1) in Y in formula (a), amine resin also includes: (i) X in formula (c) as a structural unit (c) derived from a diamine compound is a structural unit (c2) represented by formula (5), (ii) As a structural unit (a) derived from a tetracarboxylic acid compound, Y in formula (a) is a structural unit (a2) represented by formula (6), (iii) Z in formula (b) as a structural unit (b) derived from a dicarboxylic acid compound is a structural unit (b2) represented by formula (5), (iv) As a structural unit (c) derived from a diamine compound, X in formula (c) is a structural unit (c1) represented by formula (3), And/or (v) Z in formula (b) as a structural unit (b) derived from a dicarboxylic acid compound is a structural unit (b1) represented by formula (2). From the viewpoints that it is easy to improve the varnish stability of the polyimide-based resin, and it is easy to improve the total light transmittance, elastic modulus, surface hardness and bending resistance of the obtained optical film, the polyamide of the present invention The imidine resin preferably has the above-mentioned (iv) and (v), and/or also the above-mentioned (iv) and (v) in addition to the structural unit (a1) represented by the formula (1) in Y in the formula (a) At least one of (i) to (iii), more preferably having the above (iv) and (v) in addition to the structural unit (a1) represented by formula (1) where Y in formula (a) And it has at least one of (i) to (iii) above. Furthermore, when the polyimide-based resin of the present invention has at least one of (i) to (iii) above, it preferably has (i) above.

In the polyimide imine resin of the present invention, the structural unit (a), the structural unit (b), and the structural unit (c) can form an amide bond represented by the above formula (D) and the above formula The structure of the amide bond represented by (E), in addition to the structure represented by (D) and (E), for example, structural unit (a) and structural unit (c) can also be formed and include the structure represented by formula (30) The structure, the structural unit (d) and the structural unit (c) different from the structural units (a) to (c) may also be formed and include the structural unit represented by the formula (31). [化40]

In formula (30), Y ¹ is a tetravalent organic group, preferably a tetravalent organic group in which the hydrogen atom in the organic group can be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. Y ¹ may also be a structural unit represented by formula (1), for example. In one embodiment of the present invention, the polyimide-based resin may include a plurality of Y ¹ , and the plurality of Y ¹ may be the same or different from each other.

In formula (31), Y ² is a trivalent organic group, preferably a trivalent organic group in which the hydrogen atom in the organic group can be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. In one embodiment of the present invention, the polyimide-based resin may include multiple types of Y ² , and the multiple types of Y ² may be the same or different from each other.

In formula (30) and formula (31), X ² and X ³ are independently a divalent organic group, preferably an organic group in which the hydrogen atom in the organic group can be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. Examples of X ² and X ^{3 include} the group described as X in formula (c) and the group described as X'in formula (2).

In one embodiment of the present invention, the polyimide-based resin includes the formula (D) composed of a structural unit (a) derived from a tetracarboxylic acid compound and a structural unit (c) derived from a diamine compound. The structural unit represented, the structural unit represented by the formula (E) composed of the structural unit (b) derived from the dicarboxylic acid compound and the structural unit (c) derived from the diamine compound, and optionally including the formula (30) The structural unit represented by and/or the structural unit represented by formula (31). From the viewpoint of easily improving the elastic modulus, total light transmittance, optical properties, and surface hardness of the optical film, in the above-mentioned polyimide-imide resin, the structure represented by formula (D) and formula (E) The unit is based on the total of the structural units represented by formula (D) and formula (E), and as the case may be, formula (30) and formula (31), preferably 80 mol% or more, more preferably 90 mol% Above, more preferably 95 mol% or more. Furthermore, in polyimide imine resins, the structural units represented by formula (D) and formula (E) are based on formula (D) and formula (E), and as appropriate, formula (30) and/ Or the total of the structural units represented by formula (31) is usually 100% or less. In addition, the above-mentioned ratio can be measured using ¹ H-NMR, or it can also be calculated from the addition ratio of raw materials.

In one embodiment of the present invention, the content of the polyamidoimide resin in the optical film relative to 100 parts by mass of the optical film is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, and more preferably It is 50 parts by mass or more, preferably 99.5 parts by mass or less, and more preferably 95 parts by mass or less. If the content of the polyimide-based resin is within the above range, it is easy to improve the optical properties, elastic modulus, and total light transmittance of the optical film.

From the viewpoint of easy prevention of wrinkles or damage of the optical film, the elastic modulus of the optical film of the present invention is preferably 5.2 GPa or more, more preferably 5.5 GPa or more, further preferably 5.8 GPa or more, and even more preferably It is 6.0 GPa or more, more preferably 6.2 GPa or more, more preferably 6.4 GPa or more, and usually 100 GPa or less. In addition, the elastic modulus can be measured using a tensile testing machine (the distance between the chucks is 50 mm, the tensile speed is 10 mm/min), for example, it can be measured by the method described in the examples. In addition, the elastic modulus can be measured using a tensile testing machine, for example, under the conditions of a distance between the chucks of 50 mm and a tensile speed of 10 mm/min, for example, by the method described in the examples.

The total light transmittance of the optical film of the present invention is preferably 80% or more, more preferably 85% or more, still more preferably 88% or more, still more preferably 89% or more, particularly preferably 90% or more, usually 100 %the following. If the total light transmittance is more than the above lower limit, it is easy to improve the visibility when the optical film is used as a front panel in particular and incorporated in a display device. The optical film of the present invention generally exhibits a higher total light transmittance, and therefore, compared with the case of using a film with a lower transmittance, for example, the luminous intensity of display elements required to obtain a certain brightness can be suppressed. Therefore, power consumption can be reduced. For example, when the optical film of the present invention is incorporated into a display device, there is a tendency to obtain a bright display even if the amount of light in the backlight device is reduced, which can help save energy. In addition, the total light transmittance can be measured using a haze meter in accordance with JIS K 7361-1:1997, for example. The total light transmittance can be the total light transmittance within the thickness range of the following optical film. Furthermore, in this specification, the so-called excellent optical properties of the optical film means that the total light transmittance is high.

The haze of the optical film of the present invention is preferably 5% or less, more preferably 4% or less, still more preferably 3% or less, still more preferably 2.5% or less, still more preferably 2% or less, and particularly preferably 1 % Or less, more preferably 0.5% or less, usually 0.01% or more. If the haze of the optical film is less than or equal to the above upper limit, it is easy to improve the visibility when the optical film is incorporated into a display device as a front panel in particular. In addition, the haze can be measured using a haze meter in accordance with JIS K 7136:2000.

The yellowness (hereinafter, sometimes referred to as YI value) of the optical film of the present invention is preferably 3.5 or less, more preferably 3.0 or less, still more preferably 2.5 or less, usually -5 or more, preferably -2 or more. If the yellowness of the optical film is less than the above upper limit, the transparency becomes good, and when used as a front panel of a display device, it can contribute to higher visibility. Furthermore, the YI value can be measured by the ultraviolet-visible-near-infrared spectrophotometer for the transmittance of light from 300 to 800 nm to obtain 3 stimulus values (X, Y, Z), and based on YI=100×(1.2769X-1.0592 Z)/Y is calculated.

The thickness of the optical film of the present invention is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 25 μm or more, particularly preferably 30 μm or more, preferably 200 μm or less, more preferably 100 μm or less, Furthermore, it is more preferably 80 μm or less, particularly preferably 60 μm or less, and it may be a combination of these upper and lower limits. If the thickness of the optical film is within the above range, it is easier to increase the elastic modulus of the optical film. Furthermore, the thickness of the optical film can be measured using a micrometer, for example, it can be measured by the method described in an Example.

The pencil hardness of at least one side of the optical film of the present invention is preferably HB or higher, more preferably F or higher. When the pencil hardness of at least one surface of the optical film is higher than the above-mentioned hardness, it is easy to prevent damage to the surface of the optical film. Furthermore, the pencil hardness can be measured in accordance with JIS K 5600-5-4:1999.

The imidization rate of the polyimide-based resin is preferably 90% or more, more preferably 93% or more, still more preferably 96% or more, and usually 100% or less. From the viewpoint of easy improvement of the optical properties of the optical film, the imidization rate is preferably at least the above lower limit. The imidization rate represents the molar amount of the amide bond in the polyamide-imide resin relative to the molar amount of the structural unit derived from the tetracarboxylic acid compound in the polyamide-imide resin The ratio of 2 times the value. Furthermore, when the polyamide-imide-based resin contains a tricarboxylic acid compound, it means that the molar amount of the amide bond in the polyamide-imide-based resin is relative to the polyamide-imide-based resin The ratio of the value of twice the molar amount of the structural unit derived from the tetracarboxylic acid compound to the total molar amount of the structural unit derived from the tricarboxylic acid compound. In addition, the imidization rate can be determined by IR (Infrared Radiation) method, NMR method, or the like.

The content of halogen atoms in the polyimide-based resin is based on the mass of the polyimide-based resin, preferably 1-40% by mass, more preferably 5-40% by mass, and still more preferably 5-30% by mass. If the content of halogen atoms is more than the above lower limit, it is easier to improve the elastic modulus, surface hardness, transparency, and visibility of the optical film. If the content of halogen atoms is less than the above upper limit, it is easy to synthesize resin.

＜Manufacturing method of resin＞ The polyamide imide resin of the present invention can be produced using a tetracarboxylic acid compound, a dicarboxylic acid compound, and a diamine compound as main raw materials. Here, the polyamide imine-based resin of the present invention includes the structural unit (a1) represented by the formula (1) in the formula (a) as the Y-based structural unit derived from the tetracarboxylic acid compound, so at least it is used The tetracarboxylic acid compound of the structure represented by formula (1) is included as a raw material.

As the tetracarboxylic acid compound used in the production of resins, for example, the tetracarboxylic acid compound in which Y in the formula (a) is the structural unit (a1) represented by the formula (1), such as aromatic tetracarboxylic dianhydride And other aromatic tetracarboxylic acid compounds. The tetracarboxylic acid compound may be used alone or in combination of two or more kinds. In addition to the dianhydride, the tetracarboxylic acid compound may be a tetracarboxylic acid compound close body such as a chlorine compound. For example, the compound represented by the said formula (8) is mentioned.

As the tetracarboxylic acid compound used in the production of resins, the compound represented by the above formula (8) (tetracarboxylic dianhydride), for example, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA ).

In addition, as other tetracarboxylic acid compounds used in the production of resins, 4,4'-oxydiphthalic dianhydride, 2,2',3,3'-benzophenone tetracarboxylic dianhydride can be cited , 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 2,2-bis(3,4-di Carboxyphenyl) propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane dianhydride, 4 ,4'-(hexafluoroisopropylidene)diphthalic dianhydride (sometimes recorded as 6FDA), 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1 -Bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,2-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxybenzene) Yl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, 4,4'-(p-phenylenedioxy ) Diphthalic dianhydride, 4,4'-(m-phenylenedioxy) diphthalic dianhydride. Also, as the monocyclic aromatic tetracarboxylic dianhydride, for example, 1,2,4,5-benzenetetracarboxylic dianhydride (pyromellitic dianhydride (PMDA)) can be cited as one of the condensed polycyclic Examples of the aromatic tetracarboxylic dianhydride include 2,3,6,7-naphthalenetetracarboxylic dianhydride.

Among these, the tetracarboxylic acid compound preferably includes 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 1,2,4,5-benzene Tetracarboxylic dianhydride (PMDA), 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 2,2 -Bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxy) Phenyl) propane dianhydride, 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,2 -Bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane bis Anhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, 4,4'-(p-phenylenedioxy)diphthalic dianhydride and 4,4'-(m-phenylenedi Oxy)diphthalic dianhydride; more preferably cited: 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) , 2,2',3,3'-biphenyltetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 4,4'-(p-phenylenedioxy) dio Phthalic acid dianhydride and 1,2,4,5-benzenetetracarboxylic dianhydride (PMDA). These can be used individually or in combination of 2 or more types.

From the viewpoints of the elastic modulus, total light transmittance, surface hardness, and bending resistance of the optical film, as the tetracarboxylic acid compound used to make the resin, it is preferable to use 3,3',4,4'-linked Phenyltetracarboxylic dianhydride (BPDA), it is also preferable to use 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 4,4'-(hexafluoroisopropylidene) two Phthalic dianhydride (6FDA).

Examples of dicarboxylic acid compounds used in the production of polyamide imine resins include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and their close relatives such as chlorine compounds, acid anhydrides, etc.; Two or more kinds of dicarboxylic acid compounds are used in combination. As the dicarboxylic acid compound, it is preferable to use terephthalic acid, isophthalic acid, 4,4'-oxybisbenzoic acid, or chlorinated compounds such as those. In addition to terephthalic acid or 4,4'-oxybisbenzoic acid or its chlorinated compounds, other dicarboxylic acid compounds may also be used. As other dicarboxylic acid compounds, specific examples include: isophthalic acid; naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; chain formula with 8 or less carbon atoms Hydrocarbon dicarboxylic acid compound and two benzoic acid compounds linked by single bond, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -or phenylene, and The other chlorinated compounds. As a specific example, 4,4'-oxybis(benzyl chloride) and terephthalate chloride are preferred, and 4,4'-oxybis(benzyl chloride) is more preferably combined with p-benzene Dimethyl chloride is used in combination.

As a diamine compound used for manufacturing the polyamide imine resin of this invention, an aromatic diamine is mentioned, for example. Furthermore, in this embodiment, the so-called "aromatic diamine" means a diamine in which an amine group is directly bonded to an aromatic ring, and a part of its structure may also include an aliphatic group or other substituents. The aromatic ring may be a monocyclic ring or a condensed ring. A benzene ring, a naphthalene ring, an anthracene ring, a sulphur ring, etc. may be exemplified. A benzene ring is preferably exemplified, but it is not limited to these.

Examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene, 2 ,6-Diaminonaphthalene and other aromatic diamines with one aromatic ring, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diamine Diphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'- Diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy) ) Benzene, bis[4-(4-aminophenoxy)phenyl] ash, bis[4-(3-aminophenoxy)phenyl] ash, 2,2-bis[4-(4- Aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis (Trifluoromethyl)-4,4'-diaminodiphenyl (sometimes referred to as TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, 9,9-bis (4-Aminophenyl) quince, 9,9-bis(4-amino-3-methylphenyl) quince, 9,9-bis(4-amino-3-chlorophenyl) quince, 9 , 9-bis(4-amino-3-fluorophenyl) pyridine and other aromatic diamines with more than two aromatic rings. These can be used individually or in combination of 2 or more types.

The aromatic diamine is preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,3'-di Amino diphenyl ether, 4,4'-diaminodiphenyl sulfonate, 3,3'-diaminodiphenyl sulfonium, 1,4-bis(4-aminophenoxy)benzene, double [4-(4-Aminophenoxy)phenyl] ash, bis[4-(3-aminophenoxy)phenyl] ash, 2,2-bis[4-(4-aminophenoxy) Yl)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethane) Group)-4,4'-diaminodiphenyl (TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-(hexafluoropropylene) two Aniline (6FDAM), more preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4 '-Diaminodiphenyl ash, 1,4-bis(4-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl] ash, 2,2-bis[ 4-(4-Aminophenoxy)phenyl)propane, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl Group (TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-(hexafluoropropylene)diphenylamine (6FDAM). These can be used individually or in combination of 2 or more types.

As the diamine compound used in the production of the polyimide-based resin of the present invention, in addition to aromatic diamines, aliphatic diamines may be further used. Furthermore, the so-called "aliphatic diamine" refers to a diamine in which an amine group is directly bonded to an aliphatic group, and a part of its structure may include an aromatic ring or other substituents. As aliphatic diamines, for example, acyclic aliphatic diamines such as hexamethylene diamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl) (Base) cyclohexane, noralkanediamine and 4,4'-diaminodicyclohexylmethane and other cyclic aliphatic diamines.

Among the above-mentioned diamine compounds, from the viewpoints that it is easy to increase the surface hardness, total light transmittance, elastic modulus, flexibility, bending resistance, and low colorability of the optical film, it is preferable to use one selected from One or more of the group consisting of aromatic diamines of biphenyl structure. More preferably, it is selected from 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)benzidine, 4,4'-bis(4-aminophenoxy)biphenyl And 4,4'-diaminodiphenyl ether, 4,4'-(hexafluoropropylene) diphenylamine at least one of the group consisting of, more preferably 2,2'-bis( Trifluoromethyl)-4,4'-diaminodiphenyl (TFMB) and/or 4,4'-(hexafluoropropylene)diphenylamine (6FDAM).

Furthermore, the above-mentioned polyamidoimide-based resin may be within a range that does not impair the various physical properties of the optical laminate. In addition to the above-mentioned tetracarboxylic acid compound, it is also possible to make tetracarboxylic acid, tricarboxylic acid and their anhydrides And derivatives from the reaction.

Examples of other tetracarboxylic acids include water adducts of anhydrides of the aforementioned tetracarboxylic acid compounds.

Examples of the tricarboxylic acid compound include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, and their close relatives such as chlorinated compounds, acid anhydrides, and the like; two or more of them may be used in combination. Specific examples include: 1,3,5-benzenetricarboxylic acid or its chlorinated compounds, anhydrides of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalenetricarboxylic acid-2,3 -Anhydride; phthalic anhydride and benzoic acid via single bond, -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -or phenylene Linked compound.

In the production of the resin, the usage amount of the diamine compound, the tetracarboxylic acid compound and/or the dicarboxylic acid compound can be appropriately selected according to the required ratio of each structural unit of the polyimide resin.

The manufacturing method of the polyimide-based resin of the present invention is not particularly limited as long as the above-mentioned polyimide-based resin can be obtained, and it is easy to improve the elastic modulus and total light transmittance of the optical film. And from the viewpoint that it is easy to improve the stability of the varnish of the polyamide imide resin, it is preferable to react the diamine compound, the tetracarboxylic acid compound, and the dicarboxylic acid compound and add the dicarboxylic acid in batches. The method for producing acid compounds produces polyamidoimide-based resins, and it is more preferable to include step (I) of reacting a diamine compound with a tetracarboxylic acid compound to produce an intermediate (A), and making the intermediate ( A) The step (II) of reacting with the dicarboxylic acid compound and the method of adding the dicarboxylic acid compound in batches in the step (II) to produce the polyimide imine resin.

It is believed that by using the method of adding dicarboxylic acid compounds in batches to produce the polyimide-based resin of the present invention, it is easy to set the weight average molecular weight of the polyimide-based resin to the range of 330,000 or more, and it is easy to improve the optical The total light transmittance and elastic modulus of the film can easily improve the stability of the varnish.

Therefore, the polyamide imine-based resin of the present invention is preferably a resin produced by a production method of reacting a diamine compound, a tetracarboxylic acid compound, and a dicarboxylic acid compound and adding the dicarboxylic acid compound in batches, and It is preferable to include the step (I) of reacting the diamine compound and the tetracarboxylic acid compound to produce the intermediate (A), and the step (II) of reacting the intermediate (A) with the dicarboxylic acid compound and then In step (II), the resin produced by adding the method for producing the dicarboxylic acid compound in batches.

In the case of producing a polyamidoimide-based resin by the production method including the above-mentioned step (I) and step (II), the step of reacting a diamine compound with a tetracarboxylic acid compound to produce an intermediate (A) ( I) The reaction temperature is not particularly limited. For example, it may be 5 to 200°C, preferably 5 to 100°C, more preferably 5 to 50°C, and still more preferably 5°C to room temperature (here, room temperature means Refers to around 25°C). The reaction time can be, for example, 1 minute to 72 hours, preferably 10 minutes to 24 hours. In addition, the reaction can be carried out while stirring in air or in an inert gas atmosphere (for example, nitrogen, argon, etc.), or can be carried out under normal pressure, under pressure, or under reduced pressure. The preferred implementation mode is to carry out while stirring under normal pressure and/or inert gas atmosphere.

In step (I), the diamine compound reacts with the tetracarboxylic acid compound to produce the intermediate (A), that is, polyamide acid. Therefore, the intermediate (A) has at least a structural unit derived from a diamine compound and a structural unit derived from a tetracarboxylic acid compound.

Then, in step (II), the intermediate (A) is reacted with the dicarboxylic acid compound. Here, it is preferable to add the dicarboxylic acid compound in batches. The dicarboxylic acid compound is added in batches to the reaction liquid obtained in step (I), and the intermediate (A) is reacted with the dicarboxylic acid compound. Instead of adding the dicarboxylic acid compound at once, but by adding in batches, it is easy to adjust the molecular weight of the polyimide-based resin to the above-mentioned preferred range. Furthermore, in this specification, the so-called batch addition means that the dicarboxylic acid compound to be added is divided into several additions. In more detail, it means that the dicarboxylic acid to be added is divided into a specific amount with specific intervals. Or add separately at a specific time. The specific interval (specific time) also includes a very short interval or time, so batch addition also includes continuous addition or continuous feeding.

In step (II), the number of batches when adding the dicarboxylic acid compound in batches can be appropriately selected according to the reaction scale or the type of raw materials, etc., preferably 2-20 times, more preferably 3-10 times, and more preferably For 3 to 6 times. If the number of batches is in the above range, it is considered that it is easy to maintain the transmittance of the optical film, and it is likely to be the most suitable structure for increasing the elastic modulus. In addition, it is considered that the weight average molecular weight of the polyimide-based resin is also easily adjusted to the above-mentioned preferable range.

The dicarboxylic acid compound can be added in equal amounts in batches or in unequal amounts. The time between each addition (sometimes referred to as the addition interval) may all be the same or different. In addition, when adding two or more dicarboxylic acid compounds, the term "addition in batches" means adding the total amount of all dicarboxylic acid compounds in batches, and the batch method of each dicarboxylic acid compound is not particularly limited. For example, each dicarboxylic acid compound may be added all at once or in batches, or each dicarboxylic acid compound may be added in batches together, or a combination of these.

In step (II), it is preferable that the weight average molecular weight of the polyamide resin relative to the weight average molecular weight of the obtained polyamide resin reaches preferably 10% or more, more preferably 15% or more , The total molar amount of the dicarboxylic acid compound to be added is preferably 1-40 mol%, more preferably 2-25 mol% of the dicarboxylic acid compound.

The reaction temperature of step (II) is not particularly limited, and may be, for example, 5 to 200°C, preferably 5 to 100°C, more preferably 5 to 50°C, and still more preferably 5 to room temperature (about 25°C). In addition, the reaction can be carried out while stirring in air or in an inert gas atmosphere (for example, nitrogen, argon, etc.), or can be carried out under normal pressure, under pressure, or under reduced pressure. A preferred aspect is to perform step (II) while stirring under normal pressure and/or an inert gas atmosphere.

In step (II), after the dicarboxylic acid compound is added in batches, the reaction is carried out by stirring for a specific time, etc., thereby obtaining a polyamide imine precursor. Furthermore, the polyimide imine precursor can be precipitated by adding a large amount of water to the reaction solution containing the polyimide imine precursor, and then filtered and concentrated. , Dry and so on.

In step (II), the intermediate (A) is reacted with the dicarboxylic acid compound to obtain a polyimide imine precursor. Therefore, the polyimide imine precursor means at least having the structural unit derived from the diamine compound, the structural unit derived from the tetracarboxylic acid, and the structural unit derived from the dicarboxylic acid compound before the imidization (pre-ring closure) ) Of polyamide imine.

In the production of the resin, the reaction temperature of the diamine compound, the tetracarboxylic acid compound, and the dicarboxylic acid compound is not particularly limited, and is, for example, 5 to 350°C, preferably 5 to 200°C, and more preferably 5 to 100°C. The reaction time is also not particularly limited, and is, for example, about 30 minutes to 10 hours. The reaction can be carried out in an inert atmosphere or under reduced pressure as needed. In a preferred aspect, the reaction is carried out while stirring under normal pressure and/or an inert gas atmosphere. Furthermore, the reaction is preferably carried out in a solvent inert to the reaction. The solvent is not particularly limited as long as it does not affect the reaction. For example, water, methanol, ethanol, ethylene glycol, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1 -Methoxy-2-propanol, 2-butoxyethanol, propylene glycol monomethyl ether and other alcoholic solvents; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, γ -Valerolactone, propylene glycol methyl ether acetate, ethyl lactate and other ester solvents; acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, methyl isobutyl ketone and other ketones Solvents; aliphatic hydrocarbon solvents such as pentane, hexane and heptane; alicyclic hydrocarbon solvents such as ethylcyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; tetrahydrofuran and dimethoxy Ether solvents such as ethane; chlorine-containing solvents such as chloroform and chlorobenzene; amine-based solvents such as N,N-dimethylacetamide and N,N-dimethylformamide; dimethyl sulfide, dimethyl Sulfur-containing solvents such as trisulfide and cyclobutane; carbonate-based solvents such as ethylene carbonate and propylene carbonate; and combinations thereof. Among these, from the viewpoint of solubility, an amide-based solvent can be preferably used.

The manufacturing method of the polyimide-based resin may further include the step (III) of imidizing the polyimide imide precursor in the presence of the imidization catalyst. By supplying the polyamide imide precursor obtained in step (II) to step (III), the structural unit part of the polyamide imide precursor having the polyamide acid structure is passed through By imidization (through ring closure), a polyamidoimide-based resin containing the structural unit represented by formula (1) and the structural unit represented by formula (2) can be obtained. Examples of the imidization catalyst include: aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; N-ethylpiperidine, N-propylpiperidine, N -Alicyclic amines such as butylpyrrolidine, N-butylpiperidine, and N-propylhexahydroazepine (monocyclic); azabicyclo[2.2.1]heptane, azabicyclo[3.2. 1] Octane, azabicyclo[2.2.2]octane, and azabicyclo[3.2.2]nonane and other alicyclic amines (polycyclic); and pyridine, 2-picoline (2-pi Pyridine), 3-methylpyridine (3-picolin), 4-methylpyridine (4-picolin), 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2, Aromatic amines such as 4-lutidine, 2,4,6-trimethylpyridine, 3,4-cyclopentenopyridine, 5,6,7,8-tetrahydroisoquinoline, and isoquinoline . Moreover, from the viewpoint of facilitating the promotion of the imidization reaction, it is preferable to use the imidization catalyst and acid anhydride together. Examples of the acid anhydride include commonly used acid anhydrides used in the imidization reaction, and specific examples thereof include aliphatic anhydrides such as acetic anhydride, propionic anhydride, and butyric anhydride, and aromatic anhydrides such as phthalic acid.

Polyamidoimine-based resins can be isolated (separation and purification) by conventional methods, such as separation methods such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, or a combination of separation methods. In a preferred aspect, a large amount of alcohol such as methanol can be added to the reaction liquid containing the polyimide-based resin to precipitate the resin and then be isolated by concentration, filtration, drying, etc.

＜Filling＞ The present invention also provides an optical film containing the above-mentioned polyimide-based resin. The optical film of the present invention may contain at least one type of filler. Examples of the filler include organic particles, inorganic particles, and the like, and preferably inorganic particles. Examples of inorganic particles include: metal oxide particles such as silicon dioxide, zirconium oxide, aluminum oxide, titanium dioxide, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide, antimony oxide, and cerium oxide, and magnesium fluoride , Sodium fluoride and other metal fluoride particles; among these, in terms of easily improving the elastic modulus and/or tearing strength of the optical film and easily improving the impact resistance, it is preferable to cite silica particles , Zirconia particles, alumina particles, more preferably silica particles. These fillers can be used alone or in combination of two or more kinds.

The average primary particle size of the filler, preferably silica particles, is usually 1 nm or more, preferably 5 nm or more, more preferably 10 nm or more, and still more preferably 15 nm or more, particularly preferably 20 nm or more. It is preferably 100 nm or less, more preferably 90 nm or less, still more preferably 80 nm or less, still more preferably 70 nm or less, particularly preferably 60 nm or less, more preferably 50 nm or less, and even more preferably 40 nm the following. If the average primary particle size of the silica particles is within the above range, it is easy to inhibit the aggregation of the silica particles and improve the optical properties of the obtained optical film. The average primary particle size of the filler can be measured by the BET (Brunauer-Emmett-Teller, Buert) method. Furthermore, the average primary particle size can also be measured by image analysis of a transmission electron microscope or a scanning electron microscope.

When the optical film of the present invention contains a filler, preferably silica particles, the content of the filler relative to 100 parts by mass of the optical film is usually 0.1 part by mass or more, preferably 1 part by mass or more, more preferably 5 Parts by mass or more, more preferably 10 parts by mass or more, still more preferably 20 parts by mass or more, particularly preferably 30 parts by mass or more, and preferably 60 parts by mass or less. If the content of the filler is more than the above lower limit, it is easy to increase the elastic modulus of the obtained optical film. In addition, if the content of the filler is less than or equal to the above upper limit, it is easy to improve the optical properties of the optical film.

＜Ultraviolet absorber＞ The optical film of the present invention may also contain at least one ultraviolet absorber. The ultraviolet absorber can be appropriately selected from those generally used as ultraviolet absorbers in the field of resin materials. The ultraviolet absorber may include a compound that absorbs light with a wavelength below 400 nm. Examples of the ultraviolet absorber include at least one compound selected from the group consisting of benzophenone-based compounds, salicylate-based compounds, benzotriazole-based compounds, and triazole-based compounds. The ultraviolet absorber can be used alone or in combination of two or more. By containing the ultraviolet absorber in the optical film, the degradation of the resin is suppressed, and therefore the visibility can be improved when the optical film of the present invention is applied to a display device or the like. In this specification, the "system compound" refers to a derivative of the compound to which the "system compound" is attached. For example, the so-called "benzophenone-based compound" refers to a compound having benzophenone as a parent skeleton and a substituent bonded to benzophenone.

When the optical film of the present invention contains an ultraviolet absorber, the content of the ultraviolet absorber relative to the mass of the polyamide imine resin contained in the optical film is preferably 0.01-10 parts by mass, more preferably 1-8 parts by mass, more preferably 2-7 parts by mass. If the content of the ultraviolet absorber is more than the above lower limit, it is easy to improve the ultraviolet absorbability. If the content of the ultraviolet absorber is equal to or less than the above upper limit, the decomposition of the ultraviolet absorber due to heat during the production of the substrate can be suppressed, and the optical properties can be easily improved, for example, the haze can be easily reduced.

＜Other additives＞ The optical film of the present invention may further contain other additives other than fillers and ultraviolet absorbers. Examples of other additives include: antioxidants, mold release agents, stabilizers, bluing agents and other colorants, flame retardants, pH adjusters, silica dispersants, lubricants, tackifiers, and leveling agents剂 etc. When other additives are contained, the content thereof may be preferably 0.001 to 20 parts by mass, more preferably 0.01 to 15 parts by mass, and still more preferably 0.1 to 10 parts by mass relative to the mass of the optical film.

(Method of manufacturing optical film) The method for manufacturing an optical film using the polyimide-imide resin of the present invention is not particularly limited. For example, it may be a manufacturing method including the following steps: (a) A step of preparing a polyimide resin varnish containing at least the above polyimide resin and a solvent (varnish preparation step), (b) The step of applying the varnish to the support material to form a coating film (coating step), and (c) The step of drying the applied liquid (coating film) to form an optical film (optical film forming step) Furthermore, the present invention also provides a polyimide resin varnish containing at least the polyimide resin of the present invention and a solvent.

In the varnish preparation step, the polyimide-based resin is dissolved in a solvent, and additives such as fillers and ultraviolet absorbers are added as needed, followed by stirring and mixing, thereby preparing a varnish. Furthermore, when silica particles are used as a filler, a silicone gel can also be added to the resin. The silicone gel uses a solvent that can dissolve the above-mentioned resin, such as the solvent used in the preparation of the following varnish. Replacement of silica gel dispersion containing silica particles.

The solvent used to prepare the varnish is not particularly limited as long as it can dissolve the above-mentioned resin. Examples of the solvent include amine-based solvents such as N,N-dimethylacetamide and N,N-dimethylformamide; γ-butyrolactone (GBL), γ-valerolactone, etc. Lactone-based solvents; sulfur-containing solvents such as dimethyl sulfide, dimethyl sulfide, and cyclobutyl sulfide; carbonate-based solvents such as ethylene carbonate and propylene carbonate; and combinations thereof (mixed solvents). Among these, an amide-based solvent or a lactone-based solvent is preferred. If a lactone-based solvent is used, it tends to become a film with higher optical properties. These solvents can be used alone or in combination of two or more. In addition, the varnish may contain water, alcohol solvents, ketone solvents, acyclic ester solvents, ether solvents, and the like. From the viewpoint of easily improving the stability of the polyimide resin varnish, the solid content concentration in the polyimide resin varnish of the present invention is preferably 1-25% by mass, more preferably 5-20% by mass, more preferably 5-15% by mass. In addition, from the viewpoint of easily improving the stability of the polyimide resin varnish, the concentration of the solvent in the polyimide resin varnish of the present invention is based on the polyimide resin varnish. The total amount is preferably 75 to 99% by mass, more preferably 80 to 95% by mass, and still more preferably 85 to 95% by mass.

The polyimide-based resin varnish containing at least the polyimide-based resin of the present invention and a solvent has high stability. When using a varnish containing a polyimide resin to produce an optical film containing a polyamide resin, there is also a case where the coating step is performed immediately after the varnish preparation step, but after the varnish preparation step, The prepared varnish is stored for a period of time, transportation, etc., so there is a situation where a certain time has passed before the coating step. If gelation of the varnish occurs during the period after the varnish preparation step to before the coating step, there are cases where sufficient coatability cannot be obtained in the coating step. In addition, the quality of the optical film, especially the optical properties, may be impaired due to the gel in the varnish. The polyimide-based resin varnish of the present invention is not prone to the above-mentioned problems due to its high stability. Furthermore, in this specification, the polyimide-based resin varnish has high stability, so even if it is left to stand at room temperature (for example, 25°C), it is preferably more than 1 day, more preferably It is 3 days or more, more preferably 10 days or more, and more preferably 30 days or more, and the gelation of the resin varnish will not occur. Furthermore, using a varnish containing a polyimide imide precursor that provides the polyimide imide resin of the present invention by performing imidization to produce the polyimide imide resin of the present invention In the case of the resin optical film, at least the varnish containing the polyimide precursor and the solvent before the imidization of the polyimide resin of the present invention also has higher stability.

In the coating step, a varnish is applied to the support by a known coating method to form a coating film. As well-known coating methods, for example, roll coating methods such as wire bar coating, reverse coating, and gravure coating, die nozzle coating method, kama coating method, die lip coating method, spin coating Cloth method, screen coating method, spray coating method, dipping method, spray method, casting method, etc.

In the film forming step, an optical film can be formed by drying the coating film and peeling it from the support. It is also possible to further provide a step of drying the optical film after peeling. The drying of the coating film can usually be carried out at a temperature of 50 to 350°C. The coating film can be dried under inert atmosphere or reduced pressure as needed.

As an example of the support material, if it is a metal-based, SUS (Steel Use Stainless) plate, if it is a resin-based, it can include: PET (Polyethylene terephthalate, polyethylene terephthalate) film, PEN (Polyethylene naphthalate, polyethylene naphthalate) film, polyamide resin film, polyimide resin film, cycloolefin polymer (COP) film, acrylic film, etc. Among them, from the viewpoint of excellent smoothness and heat resistance, a PET film, a COP film, etc. are preferred, and further, from the viewpoint of adhesion to an optical film and cost, a PET film is more preferred.

The use of the optical film of the present invention is not particularly limited, and can be used for various purposes. The optical film of the present invention may be a single layer as described above, or may be a laminate, and the optical film of the present invention may be used directly, or it may be used as a laminate with other films. Furthermore, when the optical film is a laminated body, all layers laminated on one or both sides of the optical film are referred to as an optical film.

(Functional layer) It can also be a functional layer of at least one area layer of the optical film of the present invention. As the functional layer, for example, an ultraviolet absorbing layer, a hard coat layer, an undercoat layer, a gas barrier layer, an adhesion layer, a hue adjustment layer, a refractive index adjustment layer, etc. may be mentioned. The functional layer can be used alone or in combination of two or more.

The ultraviolet absorbing layer is a layer with ultraviolet absorbing function, for example, is composed of a main material selected from the group consisting of ultraviolet curable transparent resin, electron beam curable transparent resin, and thermosetting transparent resin and dispersed in the main material It is composed of UV absorbers.

A hard coat layer can also be provided on at least one side of the optical film of the present invention. The thickness of the hard coat layer is not particularly limited, and may be, for example, 2 to 100 μm. If the thickness of the hard coat layer is in the above range, sufficient abrasion resistance can be ensured, and the bending resistance is unlikely to decrease, and the problem of curling due to hardening shrinkage tends to occur. The hard coat layer can be formed by curing a hard coat composition containing a reactive material that can form a cross-linked structure by irradiation with active energy rays or by applying thermal energy, and is preferably formed by irradiation with active energy rays. Active energy rays are defined as energy rays that can decompose compounds that produce active species to produce active species. Examples include visible light, ultraviolet rays, infrared rays, X-rays, α rays, β rays, γ rays, and electron beams; preferably List ultraviolet rays. The above-mentioned hard coating composition contains at least one polymer of a radical polymerizable compound and a cation polymerizable compound.

The above-mentioned radically polymerizable compound is a compound having a radically polymerizable group. The radical polymerizable group possessed by the above radical polymerizable compound may be a functional group capable of generating a radical polymerization reaction. Examples include groups containing a carbon-carbon unsaturated double bond. Specifically, examples include : Vinyl, (meth)acrylic acid, etc. In addition, when the above-mentioned radically polymerizable compound has two or more radically polymerizable groups, the radically polymerizable groups may be the same or different. In terms of increasing the hardness of the hard coat layer, the number of radical polymerizable groups contained in one molecule of the radical polymerizable compound is preferably 2 or more. As the above-mentioned radically polymerizable compound, in terms of the high degree of reactivity, it is preferable to cite a compound having a (meth)acryloyl group. Specifically, for example, there are 2 to 6 (form) groups per molecule. ((Meth)acrylic acid ester) compound known as polyfunctional acrylate monomer or known as epoxy (meth)acrylate, (meth)acrylate urethane, polyester (meth)acrylate An oligomer with several (meth)acrylic acid groups in the molecule and a molecular weight of several hundred to several thousand; preferably selected from epoxy (meth)acrylate and (meth)acrylate urethane And one or more of polyester (meth)acrylates.

The above-mentioned cationically polymerizable compound is a compound having a cationically polymerizable group such as an epoxy group, an oxetanyl group, and a vinyl ether group. In terms of increasing the hardness of the hard coat layer, the number of cationically polymerizable groups contained in the cationically polymerizable compound per molecule is preferably 2 or more, more preferably 3 or more.

Furthermore, as the above-mentioned cationically polymerizable compound, a compound having at least one of an epoxy group and an oxetanyl group as a cationically polymerizable group is preferred. In terms of small shrinkage accompanying the polymerization reaction, cyclic ether groups such as epoxy groups and oxetanyl groups are preferred. In addition, the compound having the epoxy group in the cyclic ether group has a compound that is easy to obtain various structures, does not adversely affect the durability of the obtained hard coat layer, and the compatibility with the radical polymerizable compound is easy to control The advantage. In addition, the oxetanyl group in the cyclic ether group has the following advantages: the degree of polymerization is easily increased compared with the epoxy group, low toxicity, and the speed of network formation obtained from the cation polymerizable compound of the hard coat layer is accelerated. , Even in the area where the radical polymerizable compound is mixed, it will not leave unreacted monomer in the film to form an independent network.

Examples of cationic polymerizable compounds having epoxy groups include: polyglycidyl ethers of polyhydric alcohols having an alicyclic ring or cyclohexene-containing rings and ring-containing compounds by using suitable oxidizing agents such as hydrogen peroxide and peracid. Alicyclic epoxy resin obtained by epoxidation of compound of pentene ring; polyglycidyl ether of aliphatic polyol or its alkylene oxide adduct, polyglycidyl ester of aliphatic long-chain polyacid, (methyl) Aliphatic epoxy resins such as homopolymers and copolymers of glycidyl acrylate; by bisphenols such as bisphenol A, bisphenol F or hydrogenated bisphenol A or their alkylene oxide adducts, caprolactone Glycidyl ether produced by the reaction of derivatives such as adduct and epichlorohydrin, and glycidyl ether type epoxy resin derived from bisphenols as novolac epoxy resins, etc.

The above-mentioned hard coating composition may further contain a polymerization initiator. Examples of the polymerization initiator include radical polymerization initiators, cationic polymerization initiators, radical and cationic polymerization initiators, etc.; they can be appropriately selected and used. The polymerization initiators are decomposed by at least one of active energy ray irradiation and heating to generate free radicals or cations and then undergo radical polymerization and cationic polymerization. The radical polymerization initiator should just be a substance that can release radical polymerization by at least one of active energy ray irradiation and heating. For example, as a thermal radical polymerization initiator, organic peroxides, such as hydrogen peroxide and perbenzoic acid, azo compounds, such as azobutyronitrile, etc. are mentioned. As active energy ray radical polymerization initiators, there are Type1 radical polymerization initiators that use the decomposition of molecules to generate free radicals, and Type2 radical polymerization initiators that coexist with tertiary amines and generate free radicals by dehydrogenation reaction. The starting agent can be used alone or in combination. The cationic polymerization initiator may be a substance that can be released by at least one of active energy ray irradiation and heating to initiate cationic polymerization. As the cationic polymerization initiator, an aromatic iodonium salt, an aromatic sulfonium salt, a cyclopentadienyl iron (II) complex, and the like can be used. These can start cationic polymerization by either or both of active energy ray irradiation or heating according to the difference in structure.

The polymerization initiator may preferably be contained in an amount of 0.1 to 10% by mass with respect to 100% by mass of the entire hard coating composition. If the content of the polymerization initiator is in the above range, the curing can be carried out sufficiently, and the mechanical properties and adhesion of the finally obtained coating film can be in a good range, and the adhesive force caused by curing shrinkage is not easily generated. Bad or cracked phenomenon and curling phenomenon.

The above-mentioned hard coating composition may further include one or more selected from the group consisting of solvents and additives. As long as the above-mentioned solvent can dissolve or disperse the above-mentioned polymerizable compound and polymerization initiator and is known as a solvent for hard coat compositions in this technical field, it can be used within a range that does not impair the effects of the present invention. The above-mentioned additives may further include inorganic particles, leveling agents, stabilizers, surfactants, antistatic agents, lubricants, antifouling agents, and the like.

The adhesive layer is a layer with adhesive function and has the function of adhering the optical film to other components. As the forming material of the adhesive layer, generally known ones can be used. For example, a thermosetting resin composition or a photocuring resin composition can be used. In this case, the resin composition can be polymerized and cured by supplying energy afterwards.

The adhesive layer may also be a layer which is called a pressure sensitive adhesive (PSA) and is attached to an object by pressing. Pressure-sensitive adhesives can be used as "substances that are adhesive at room temperature and adhere to the material to be bonded with a lighter pressure" (JIS K 6800), and can also be used as "incorporating specific ingredients in protection In the film (microcapsule), it is a capsule adhesive agent that can maintain stability by appropriate methods (pressure, heat, etc.) before breaking the film." (JIS K 6800) Capsule adhesive.

The hue adjustment layer is a layer with the function of hue adjustment, and is a layer that can adjust the layered body including the optical film to the target hue. The hue adjusting layer is, for example, a layer containing resin and coloring agent. Examples of the colorant include inorganic pigments such as titanium oxide, zinc oxide, red lead, titanium oxide-based calcined pigments, ultramarine blue, cobalt aluminate, and carbon black; azo-based compounds, quinacridone-based compounds, and anthraquinone Organic pigments such as compounds, perylene compounds, isoindolinone compounds, phthalocyanine compounds, quinophthalone compounds, anthracene compounds, and diketopyrrolopyrrole compounds; barium sulfate and calcium carbonate Pigments; and dyes such as basic dyes, acid dyes, and mordant dyes.

The refractive index adjustment layer is a layer having a refractive index adjustment function, for example, a layer that has a refractive index different from that of an optical film and can give a specific refractive index to the optical laminate. The refractive index adjustment layer may be, for example, a resin layer containing appropriately selected resin and pigments as appropriate, or a metal film. Examples of pigments that adjust the refractive index include silica, alumina, antimony oxide, tin oxide, titanium oxide, zirconium oxide, and tantalum oxide. The average primary particle size of the pigment may be 0.1 μm or less. By setting the average primary particle size of the pigment to 0.1 μm or less, the diffuse reflection of the light passing through the refractive index adjustment layer can be prevented, thereby preventing the decrease in transmittance. Examples of metals used for the refractive index adjustment layer include titanium oxide, tantalum oxide, zirconium oxide, zinc oxide, tin oxide, silicon oxide, indium oxide, acid titanium nitride, titanium nitride, acid silicon nitride, and nitrogen. Metal oxide or metal nitride such as silicide.

The optical film of the present invention may be a single layer or a laminate. For example, the optical film manufactured as described above may be used as it is, or it may be used as a laminate with other films.

In an embodiment of the present invention, the optical film may also have a protective film on at least one side (single side or both sides). For example, when the optical film has a functional layer on one side, the protective film may be laminated on the surface on the optical film side or the functional layer side, or on both the optical film side and the functional layer side. When there are functional layers on both sides of the optical film, the protective film can be laminated on the surface of one of the functional layers or on the surface of the two functional layers. The protective film is a film for temporarily protecting the surface of the optical film or the functional layer, and is not particularly limited as long as it is a peelable film that can protect the surface of the optical film or the functional layer. Examples of protective films include polyester resin films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resin films such as polyethylene and polypropylene films. Resin film, acrylic resin film, etc.; preferably selected from the group consisting of polyolefin resin film, polyethylene terephthalate resin film, and acrylic resin film. When the optical film has two protective films, each protective film may be the same or different.

The thickness of the protective film is not particularly limited, and is usually 10 to 120 μm, preferably 15 to 110 μm, and more preferably 20 to 100 μm. When the optical film has two protective films, the thickness of each protective film may be the same or different.

In a preferred embodiment of the present invention, the optical film of the present invention is effectively used as a front panel of a display device, especially a front panel of a flexible display device (hereinafter, sometimes referred to as a window film). The flexible display device has, for example, a flexible functional layer and an optical film that overlaps the flexible functional layer and functions as a front panel. That is, the front panel of the flexible display device is arranged on the visible side of the flexible functional layer. The front panel has the function of protecting the flexible functional layer.

Examples of display devices include wearable devices such as televisions, smart phones, mobile phones, car navigation systems, tablet PCs, portable game consoles, electronic paper, indicators, display boards, clocks, and smart watches. As the flexible display device, all display devices having flexibility characteristics can be cited, and among them, a bendable foldable display device or a cocoa rollable display device is preferred.

[Flexible display device] The invention also provides a flexible display device equipped with the optical film of the invention. The optical film of the present invention is preferably used as a front panel in a flexible display device, and the front panel is sometimes called a window film. The flexible display device includes a laminate for a flexible display device and an organic EL display panel. The laminate for a flexible display device is arranged on the viewing side of the organic EL display panel and is configured to be bendable. The laminate for a flexible display device may include a window film, a polarizing plate (preferably a circular polarizing plate), a touch sensor, etc. in any order, preferably the window film is layered in order from the viewing side , Polarizing plate, touch sensor or window film, touch sensor, polarizing plate. If there is a polarizing plate on the visible side of the touch sensor, the pattern of the touch sensor is not easily visible and the visibility of the displayed image becomes good, which is better. Each member can be laminated using adhesives, adhesives, etc. In addition, it may be provided with a light-shielding pattern formed on at least one surface of any one of the above-mentioned window film, polarizer, and touch sensor.

[Polarizer] The flexible display device of the present invention may further include a polarizing plate, preferably a circular polarizing plate. The circular polarizer is a functional layer that has the function of transmitting only the right or left circularly polarized light component by laminating the λ/4 retardation plate on the linear polarizer. For example, it is used to block the external light that is converted into right-handed circularly polarized light and then reflected on the organic EL panel to become left-handed circularly polarized light outer boundary light, and only transmits the luminous components of the organic EL, thereby suppressing the influence of reflected light. Make the image easy to see. In order to achieve the circularly polarized light function, the absorption axis of the linear polarizer and the slow axis of the λ/4 retardation plate must be 45° in theory, and 45±10° in actual use. The linear polarizing plate and the λ/4 retardation plate do not necessarily need to be laminated adjacently, as long as the relationship between the absorption axis and the slow phase axis satisfies the above range. It is preferable to achieve complete circularly polarized light under the total wavelength, but this is not necessarily the case in actual use. Therefore, the circular polarizer in the present invention also includes an elliptical polarizer. It is also preferable to laminate a λ/4 retardation film on the visibility side of the linear polarizer so that the emitted light becomes circularly polarized light to improve the visibility in the state of wearing polarized sunglasses.

The linear polarizer is a functional layer that has the function of passing light vibrating in the direction of the transmission axis and blocking the polarized light of the vibration component perpendicular to it. The above-mentioned linear polarizing plate may also be a structure having a linear polarizing element alone or a linear polarizing element and a protective film attached to at least one surface thereof. The thickness of the linear polarizing plate may be 200 μm or less, preferably 0.5-100 μm. If the thickness is in the above range, there is a tendency that flexibility is not easily reduced. The linear polarizing element may be a film-type polarizing element manufactured by dyeing and stretching a polyvinyl alcohol (PVA) film. By adsorbing dichroic dyes such as iodine to the PVA-based film aligned by stretching, or stretching while adsorbing on PVA, the dichroic dyes are aligned, thereby exhibiting polarization performance. In the manufacture of the above-mentioned film-type polarizing element, it may additionally have steps such as swelling, cross-linking by boric acid, washing by aqueous solution, and drying. The stretching or dyeing step can be performed by a PVA-based film alone, or in a state of being laminated with other films such as polyethylene terephthalate. The thickness of the PVA-based film used is preferably 10-100 μm, and the stretching ratio is preferably 2-10 times. Furthermore, as another example of the above-mentioned polarizing element, it may be a liquid crystal coating type polarizing element formed by coating a liquid crystal polarizing composition. The liquid crystal polarizing composition may include a liquid crystal compound and a dichroic dye compound. The above-mentioned liquid crystalline compound only needs to have the property of displaying a liquid crystal state, especially if it has a high-order alignment state equal to a smectic array, it can exhibit a higher polarization performance, so it is preferable. Moreover, it is also preferable that the liquid crystal compound has a polymerizable functional group.

The dichroic dye is a dye that is aligned with the liquid crystal compound to exhibit dichroism. The dichroic dye itself may have liquid crystallinity or may have a polymerizable functional group. Any compound in the liquid crystal polarizing composition has a polymerizable functional group. The above-mentioned liquid crystal polarizing composition may further include a starter, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like. The above-mentioned liquid crystal polarizing layer is manufactured by coating a liquid crystal polarizing composition on an alignment film to form a liquid crystal polarizing layer. The liquid crystal polarizing layer can be formed thinner than the film-type polarizing element. The thickness of the above-mentioned liquid crystal polarizing layer may preferably be 0.5-10 μm, more preferably 1-5 μm. The above-mentioned alignment film can be produced, for example, by coating an alignment film forming composition on a substrate and imparting alignment by rubbing, polarized light irradiation, or the like. In addition to the alignment agent, the alignment film forming composition may also include a solvent, a crosslinking agent, an initiator, a dispersant, a leveling agent, a silane coupling agent, and the like. As the above-mentioned alignment agent, for example, polyvinyl alcohols, polyacrylates, polyamides, and polyimines can be used. In the case of applying optical alignment, it is preferable to use an alignment agent containing a cinnamate group. The weight average molecular weight of the polymer used as the alignment agent can be about 10,000-1,000,000. From the viewpoint of the alignment restriction force, the thickness of the alignment film is preferably 5 to 10,000 nm, more preferably 10 to 500 nm. The liquid crystal polarizing layer may be separated from the base material and then transferred and laminated, or the base material may be directly laminated. The above-mentioned base material is also preferably used as a transparent base material for a protective film, a phase difference plate, and a window.

The protective film may be a transparent polymer film, and the materials and additives used for the transparent substrate may be used. Preferred are cellulose-based films, olefin-based films, acrylic films, and polyester-based films. It can also be a coating type protective film obtained by coating and curing a cationic curing composition such as epoxy resin or a radical curing composition such as acrylic ester. It can also contain plasticizers, ultraviolet absorbers, infrared absorbers, pigments or dyes, fluorescent whitening agents, dispersants, heat stabilizers, light stabilizers, antistatic agents, antioxidants, and lubricating agents as needed. Agent, solvent, etc. The thickness of the protective film can be 200 μm or less, preferably 1-100 μm. If the thickness of the protective film is in the above range, the flexibility of the protective film is not easily reduced. The protective film can also take into account the role of the transparent substrate of the window.

The above-mentioned λ/4 retardation plate is a film that provides a λ/4 retardation in a direction orthogonal to the traveling direction of incident light (in-plane direction of the film). The above-mentioned λ/4 retardation plate may be a stretched retardation plate manufactured by stretching a polymer film such as a cellulose-based film, an olefin-based film, or a polycarbonate-based film. It can also contain phase difference adjusters, plasticizers, ultraviolet absorbers, infrared absorbers, pigments or dyes and other coloring agents, fluorescent whitening agents, dispersants, heat stabilizers, light stabilizers, and antistatic agents. , Antioxidants, lubricants, solvents, etc. The thickness of the extended phase difference plate may be 200 μm or less, preferably 1-100 μm. If the thickness is in the above range, there is a tendency that the flexibility of the film is not easily reduced. Furthermore, as another example of the above-mentioned λ/4 retardation plate, it may be a liquid crystal coating type retardation plate formed by applying a liquid crystal composition. The above-mentioned liquid crystal composition contains a liquid crystal compound having the property of displaying liquid crystal states such as nematic, cholesteric, smectic, and the like. Any compound containing a liquid crystal compound in the liquid crystal composition has a polymerizable functional group. The above-mentioned liquid crystal coating type retardation plate may further include a starter, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like. The liquid crystal coating type retardation plate can be manufactured by forming a liquid crystal retardation layer by applying and curing a liquid crystal composition on an alignment film in the same manner as described in the liquid crystal polarizing layer. The liquid crystal coating type retardation plate can be made thinner than the extension type retardation plate. The thickness of the above-mentioned liquid crystal polarizing layer may usually be 0.5-10 μm, preferably 1-5 μm. The liquid crystal coating type retardation plate may be peeled from the base material and laminated after transfer, or the base material may be laminated directly. It is also preferable that the above-mentioned substrate plays a role as a transparent substrate of a protective film, a phase difference plate, and a window.

Generally speaking, the shorter the wavelength, the greater the birefringence, and the longer the wavelength, the more materials exhibiting the smaller the birefringence. In this case, since the phase difference of λ/4 cannot be achieved in the full visible light region, the in-plane phase difference of λ/4 becomes 100 to 180 nm, preferably 130 to 560 nm, where the visibility is higher. There are many cases of 150 nm design. It is preferable to use a reverse dispersion λ/4 retardation plate that uses a material having birefringence wavelength dispersion characteristics opposite to that of usual, which can provide good visibility. As such a material, it is also preferable to use the one described in Japanese Patent Laid-Open No. 2007-232873 in the case of an extended retardation plate, and to use Japanese Patent Laid-Open 2010 in the case of a liquid crystal coating type retardation plate. -30979 Bulletin. In addition, as another method, a technique of obtaining a wide-band λ/4 retardation plate by combining with a λ/2 retardation plate is also known (Japanese Patent Laid-Open No. 10-90521). The λ/2 retardation plate is also manufactured using the same material method as the λ/4 retardation plate. The combination of the extension type retardation plate and the liquid crystal coating type retardation plate is arbitrary, but it is preferable to use the liquid crystal coating type retardation plate to make the thickness thinner. There is also known a method of laminating a positive C flat plate on the above-mentioned circular polarizing plate in order to improve the visibility in the oblique direction (Japanese Patent Laid-Open No. 2014-224837). The positive C plate can be a liquid crystal coating type retardation plate or an extended type retardation plate. The phase difference in the thickness direction is usually -200 to -20 nm, preferably -140 to -40 nm.

[Touch Sensor] The flexible display device of the present invention may further include a touch sensor. The touch sensor can be used as an input mechanism. As a touch sensor, various styles such as a resistive film method, a surface elastic wave method, an infrared method, an electromagnetic induction method, and an electrostatic capacitance method are proposed, and any method may be adopted. Among them, the electrostatic capacitance method is preferred. The capacitive touch sensor is divided into an active area and an inactive area located outside the active area. The active area corresponds to the area (display portion) of the display screen displayed on the display panel and is an area that senses the user's touch, and the inactive area corresponds to the area (non-display portion) that does not display the image on the display device. The touch sensor may include: a substrate, which has the characteristics of flexibility; a sensing pattern, which is formed on the active area of the substrate; and each sensing line, which is formed on the inactive area of the substrate, and is used to pass through The pad part connects the sensing pattern with an external driving circuit. As a substrate with flexible characteristics, the same material as the transparent substrate of the above-mentioned window can be used. In terms of suppressing cracks of the touch sensor, the substrate of the touch sensor is preferably one with a toughness of 2,000 MPa% or more. More preferably, the toughness may be 2,000 to 30,000 MPa%. Here, toughness is defined as the area under the curve before reaching the failure point in the stress (MPa)-strain (%) curve obtained through the tensile test of the polymer material.

The aforementioned sensing pattern may include a first pattern formed in the first direction and a second pattern formed in the second direction. The first pattern and the second pattern are arranged in different directions. The first pattern and the second pattern are formed on the same layer. In order to sense the touched location, each pattern must be electrically connected. The first pattern is a form in which the unit patterns are connected to each other via a joint, and the second pattern is a structure in which the unit patterns are separated from each other into island shapes. Therefore, in order to electrically connect the second pattern, another bridge electrode is necessary. The sensing pattern can use well-known transparent electrode materials. Examples include: indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), indium gallium zinc oxide (IGZO), cadmium tin oxide ( CTO), PEDOT (poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene)), carbon nanotubes (CNT), graphene, metal wires, etc., these can be separated or combined Mixed use of the above. Preferably, ITO can be used. The metal used for the metal wire is not particularly limited, and examples thereof include silver, gold, aluminum, copper, iron, nickel, titanium, selenium, and chromium. These can be used individually or in mixture of 2 or more types.

The bridge electrode can be formed on the upper part of the insulating layer through the insulating layer on the upper part of the sensing pattern, and the bridge electrode can be formed on the substrate, and the insulating layer and the sensing pattern can be formed thereon. The above-mentioned bridge electrode can be formed of the same material as the sensing pattern, or can be formed of metals such as molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium, or an alloy of two or more of these. The first pattern and the second pattern must be electrically insulated, so an insulating layer is formed between the sensing pattern and the bridge electrode. The insulating layer can also be formed only between the joints of the first pattern and the bridging electrodes, or can be formed in the structure of the layer covering the sensing pattern. In the latter case, the bridge electrode can be connected to the second pattern via a contact hole formed in the insulating layer. The above-mentioned touch sensor may further include an optical adjustment layer between the substrate and the electrode as a mechanism for appropriately compensating for the difference in transmittance, which is the patterned area with the pattern and the non-patterned area with no pattern. The difference in transmittance between the regions, specifically the difference in light transmittance induced by the difference in refractive index in these regions; the optical adjustment layer may include an inorganic insulating material or an organic insulating material. The optical adjustment layer can be formed by coating a photocuring composition containing a photocuring organic binder and a solvent on a substrate. The above-mentioned photocurable composition may further contain inorganic particles. The refractive index of the optical adjustment layer can be increased by the above-mentioned inorganic particles. The photocurable organic adhesive may include, for example, copolymers of monomers such as acrylate monomers, styrene monomers, and carboxylic acid monomers. The photocurable organic adhesive may be, for example, a copolymer containing different repeating units such as epoxy-containing repeating units, acrylate repeating units, and carboxylic acid repeating units. The above-mentioned inorganic particles may include zirconia particles, titania particles, alumina particles, and the like, for example. The aforementioned photocurable composition may further contain various additives such as a photopolymerization initiator, a polymerizable monomer, and a curing auxiliary agent.

[Next layer] The layers (windows, polarizers, touch sensors) forming the above-mentioned laminate for flexible display devices and the film members (linear polarizers, λ/4 phase difference plates, etc.) constituting the layers can be bonded by adhesives. As the adhesive, water-based adhesives, organic solvent-based adhesives, solvent-free adhesives, solid adhesives, solvent-volatile adhesives, water-based solvent-volatile adhesives, moisture-curing adhesives, and heat-curing adhesives can be used General-purpose users such as adhesives, anaerobic curing type adhesives, active energy ray curing type adhesives, curing agent mixed type adhesives, hot melt type adhesives, pressure sensitive type adhesives (adhesives), rewetting type adhesives, etc. Among them, water-based solvent volatile adhesives, active energy ray hardening adhesives, and adhesives are often used. The thickness of the subsequent layer can be appropriately adjusted according to the required adhesive force, etc., for example, 0.01-500 μm, preferably 0.1-300 μm. The adhesive layer may have multiple layers in the above-mentioned laminate for flexible display devices, but the thickness of each layer and the type of adhesive used may be the same or different.

As the above-mentioned water-based solvent-volatile adhesive, water-dispersed polymers such as polyvinyl alcohol-based polymers, starch, etc., ethylene-vinyl acetate-based latex, styrene-butadiene-based latex, and other water-dispersed polymers can be used as the main Agent polymer. In addition to water and the above-mentioned main agent polymer, crosslinking agents, silane compounds, ionic compounds, crosslinking catalysts, antioxidants, dyes, pigments, inorganic fillers, organic solvents, etc. can also be formulated. In the case of bonding by the above-mentioned water-based solvent-volatile adhesive, the above-mentioned water-based solvent-volatile adhesive may be injected between the layers to be bonded, and the bonded layers may be bonded and dried to impart adhesiveness. In the case of using the above-mentioned water-based solvent-volatile adhesive, the thickness of the adhesive layer may be 0.01-10 μm, preferably 0.1-1 μm. When the water-based solvent volatile adhesive is used to form multiple layers, the thickness of each layer and the type of the adhesive may be the same or different.

The active energy ray curable adhesive can be formed by irradiating active energy rays to harden an active energy ray curable composition containing a reactive material that forms the adhesive layer. The active energy ray hardening composition may contain at least one polymer of the same radical polymerizable compound and cation polymerizable compound as the hard coat composition. The above-mentioned radically polymerizable compound is the same as the hard coat composition, and the same type as the hard coat composition can be used. As the radical polymerizable compound used for the adhesive layer, a compound having an acrylic group is preferred. In order to reduce the viscosity of the adhesive composition, it is also preferable to include a monofunctional compound.

The above-mentioned cationically polymerizable compound is the same as the hard coat composition, and the same type as the hard coat composition can be used. The cationic polymerizable compound used in the active energy ray hardening composition is preferably an epoxy compound. In order to reduce the viscosity of the adhesive composition, it is also preferable to include a monofunctional compound as a reactive diluent. The active energy ray composition may further contain a polymerization initiator. As the polymerization initiator, there are radical polymerization initiators, cationic polymerization initiators, radical and cationic polymerization initiators, etc., which can be appropriately selected and used. The polymerization initiators are decomposed by at least one of active energy ray irradiation and heating to generate free radicals or cations and allow radical polymerization and cationic polymerization to proceed. In the description of the hard coating composition, an initiator that can initiate at least one of radical polymerization or cationic polymerization by active energy ray irradiation can be used.

The active energy ray hardening composition may further include an ion scavenger, an antioxidant, a chain transfer agent, an adhesion imparting agent, a thermoplastic resin, a filler, a fluidized viscosity adjuster, a plasticizer, a defoamer solvent, an additive, and a solvent. In the case of bonding by the active energy ray-curing adhesive, the active energy ray-curing composition can be applied to either or both of the layers to be adhered, and then bonded by either The layer or the two adhering layers are irradiated with active energy rays to cure and then adhere. In the case of using the active energy ray-curable adhesive, the thickness of the adhesive layer may be 0.01-20 μm, preferably 0.1-10 μm. When the active energy ray-curable adhesive is used to form multiple layers, the thickness of each layer and the type of adhesive used may be the same or different.

As the above-mentioned adhesive, any one of acrylic adhesives, urethane-based adhesives, rubber-based adhesives, silicone-based adhesives, etc. may be classified in accordance with the main agent polymer and used. In addition to the main agent polymer, the adhesive can also be blended with crosslinking agents, silane compounds, ionic compounds, crosslinking catalysts, antioxidants, adhesion imparting agents, plasticizers, dyes, pigments, inorganic fillers, etc. The components constituting the above-mentioned adhesive are dissolved and dispersed in a solvent to obtain an adhesive composition, and the adhesive composition is applied on a substrate and dried to form an adhesive layer (adhesive layer). The adhesive layer can be directly formed, or it can be transferred to a substrate formed separately. In order to cover the adhesive surface before bonding, it is also preferable to use a release film. In the case of using the above-mentioned adhesive, the thickness of the adhesive layer may be 1 to 500 μm, preferably 2 to 300 μm. When the above-mentioned adhesive is used to form multiple layers, the thickness of each layer and the type of adhesive used may be the same or different.

[Shading Pattern] The above-mentioned light-shielding pattern can be applied as at least a part of the frame or housing of the above-mentioned flexible display device. The wiring arranged at the edge of the flexible display device is covered by the light-shielding pattern so that it is not easily visible, thereby improving the visibility of the image. The aforementioned light-shielding pattern may be in the form of a single layer or multiple layers. The color of the shading pattern is not particularly limited, and can have multiple colors such as black, white, and metallic. The light-shielding pattern can be formed by pigments and polymers such as acrylic resins, ester resins, epoxy resins, polyurethanes, polysiloxanes, etc., to specifically express colors. These can be used alone or in a mixture of two or more kinds. The above-mentioned light-shielding pattern can be formed by various methods such as printing, lithography, and inkjet. The thickness of the light-shielding pattern is usually 1-100 μm, preferably 2-50 μm. In addition, a shape such as an inclination may be provided in the thickness direction of the light shielding pattern. [Example]

Hereinafter, the present invention will be further described in detail through examples. The "%" and "parts" in the examples mean mass% and parts by mass unless otherwise specified. First, the evaluation method will be described.

＜Determination of elastic modulus＞ The "Autograph AG-IS" manufactured by Shimadzu Corporation was used to measure the elastic modulus of the polyamide imide films obtained in the examples and comparative examples. A film with a width of 10 mm is made, and the stress-strain curve is measured under the conditions of a distance between the chucks of 50 mm and a stretching speed of 10 mm/min, and the elastic modulus is calculated from the slope.

＜Measurement of total light transmittance＞ According to JIS K 7105:1981 and manufactured by Suga Test Instruments (stock), the automatic direct-reading haze meter HGM-2DP is used to measure the total light transmittance (Tt) of the sample for the optical films obtained in the examples and comparative examples .

＜Measurement of weight average molecular weight (Mw)＞ Gel Permeation Chromatography (GPC) determination (1) Pretreatment method Add DMF lysate (10 mmol/L lithium bromide solution) to the sample at a concentration of 2 mg/mL, stir at 80°C for 30 minutes while heating, and after cooling, filter with a 0.45 μm membrane filter. As the measurement solution. (2) Measurement conditions Tubular column: TSKgel α-2500 ((7) diameter 7.8 mm×300 mm) × 1 piece, α-M ((13) diameter 7.8 mm×300 mm) × 2 pieces manufactured by Tosoh (stock) Eluent: DMF (10 mmol/L lithium bromide addition) Flow rate: 1.0 mL/min Detector: RI detector Column temperature: 40℃ Injection volume: 100 μL Molecular weight standard: standard polystyrene

＜Measurement of thickness＞ The thickness of the polyimide film obtained in the examples and comparative examples was measured using a micrometer ("ID-C112XBS" manufactured by Mitutoyo Co., Ltd.).

＜Varnish stability test＞ Adjust the concentration so that the viscosity becomes 30,000 ~ 40,000 cP, mix the polyamide imide resin and dimethyl acetamide, stir and heat at 70°C to make a varnish. Put 10 g of the made varnish into a glass spiral tube with a diameter of 27 mm, and let it stand for 3 days in an upright state at 25°C. After that, the glass spiral tube was laid down by 90°, and further left to stand for 1 hour. Those whose liquid level became horizontal after 1 hour were judged to be a solution state, and those whose liquid level was not horizontal were judged to be a gel state. In addition, in the results described in Table 1, when it is judged as a solution state, it is set as ○, and when it is judged as a gel state, it is set as x.

<Example 1> [Preparation of polyamide imide resin (1)] Add 2,2'-bis(trifluoromethyl)benzidine (TFMB) and N,N to a separable flask equipped with a stirring blade under a nitrogen atmosphere so that the solid content of TFMB becomes 5.39% by mass. -Dimethylacetamide (DMAc), then add 11.11 mol% of 4,4'-(hexafluoropropylene)diphenylamine (6FDAM) relative to TFMB, stir at room temperature while mixing TFMB and 6FDAM Dissolved in DMAc. Then, 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was added to the flask so that it became 44.67 mol% with respect to TFMB, and stirred at room temperature for 3 hours. Then, after cooling to 10 degreeC, terephthalic acid chloride (TPC) was added so that it might become 60.30 mol% with respect to TFMB, and it stirred for 30 minutes. Thereafter, the same amount of DMAc as the DMAc added for the first time was added, and after stirring for 10 minutes, TPC was added so as to be 6.70 mol% with respect to TFMB, and stirred for 2 hours. Then, 60.30 mol% of diisopropylethylamine and 4-picoline were added to the flask with respect to TFMB, and 313.67 mol% of acetic anhydride was added to TFMB. After stirring for 30 minutes, the internal temperature was raised to 70°C. , And further stirred for 3 hours to obtain a reaction liquid. The obtained reaction liquid was cooled to room temperature, and was linearly thrown into a large amount of methanol, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Then, the precipitate was dried under reduced pressure at 60°C to obtain a polyimide resin (1).

[Manufacturing of polyimide film (1)] To the obtained polyimide resin (1), DMAc was added so that the concentration became 6.5% by mass to prepare a polyimide varnish (1), and it was left at 25°C for 3 days. After that, the polyamide obtained by applying an applicator was applied to the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") so that the thickness of the self-supporting film became 45 μm. The amine varnish (1) was dried at 50°C for 30 minutes and then at 140°C for 15 minutes to obtain a self-supporting film. The self-supporting film was fixed to the mold frame, and then dried at 200° C. for 60 minutes to obtain a polyamide imide film (1) with a thickness of 40 μm.

<Example 2> [Preparation of polyamide imide resin (2)] Add TFMB and DMAc to a separable flask with a stirring blade under a nitrogen atmosphere so that the solid content of TFMB becomes 4.81% by mass, and then add 25.00 mol% of 6FDAM to TFMB, and stir at room temperature. , While dissolving TFMB and 6FDAM in DMAc. Then, BPDA was added to the flask so that it might become 50.25 mol% with respect to TFMB, and it stirred at room temperature for 3 hours. Then, after cooling to 10 degreeC, TPC was added so that it might become 67.84 mol% with respect to TFMB, and it stirred for 30 minutes. Thereafter, the same amount of DMAc as the DMAc added for the first time was added, and after stirring for 10 minutes, TPC was added so as to be 7.54 mol% with respect to TFMB, and stirred for 2 hours. Then, 75.38 mol% of diisopropylethylamine and 4-picoline were added to the flask with respect to TFMB, and 351.76 mol% of acetic anhydride was added to TFMB. After stirring for 30 minutes, the internal temperature was increased to 70°C , And further stirred for 3 hours to obtain a reaction liquid. The obtained reaction liquid was cooled to room temperature, and was linearly thrown into a large amount of methanol, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Then, the precipitate was dried under reduced pressure at 60°C to obtain a polyimide resin (2).

[Manufacturing of Polyimide Film (2)] To the obtained polyimide resin (2), DMAc was added so that the concentration became 6.0% by mass to prepare a polyimide varnish (2), and it was left at 25°C for 3 days. After that, the polyamide obtained by applying an applicator was applied to the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") so that the thickness of the self-supporting film became 45 μm. Amine varnish (2) was dried at 50°C for 30 minutes, and then at 140°C for 15 minutes to obtain a self-supporting film. The self-supporting film was fixed to the mold frame and dried at 200° C. for 60 minutes to obtain a polyamide imide film (2) with a thickness of 40 μm.

<Example 3> [Preparation of polyamide imide resin (3)] Add TFMB and DMAc to a separable flask equipped with a stirring wing under a nitrogen atmosphere so that the solid content of TFMB becomes 5.44% by mass, and then add 11.11 mol% of 6FDAM to TFMB, and stir at room temperature. , While dissolving TFMB and 6FDAM in DMAc. Then, BPDA was added to the flask so that it might become 34.01 mol% with respect to TFMB, and it stirred at room temperature for 3 hours. Then, after cooling to 10 degreeC, TPC was added so that it might become 71.43 mol% with respect to TFMB, and it stirred for 30 minutes. After that, the same amount of DMAc as the DMAc added for the first time was added, and after stirring for 10 minutes, TPC was added so as to be 7.94 mol% with respect to TFMB, and the mixture was stirred for 2 hours. Then, 79.37 mol% of diisopropylethylamine and 4-picoline were added to the flask with respect to TFMB, and 238.10 mol% of acetic anhydride was added to the flask with respect to TFMB. After stirring for 30 minutes, the internal temperature was raised to 70°C. , And further stirred for 3 hours to obtain a reaction liquid. The obtained reaction liquid was cooled to room temperature, and was linearly thrown into a large amount of methanol, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Then, the precipitate was dried under reduced pressure at 60°C to obtain a polyimide resin (3).

[Manufacturing of polyimide film (3)] To the obtained polyimide resin (3), DMAc was added so that the concentration became 8.0% by mass to prepare a polyimide varnish (3), and it was left at 25°C for 3 days. Thereafter, the polyamide obtained by applying an applicator was applied to the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") so that the thickness of the self-supporting film became 55 μm. The amine varnish (3) was dried at 50°C for 30 minutes, and then at 140°C for 15 minutes to obtain a self-supporting film. The self-supporting film was fixed to the mold frame, and then dried at 200° C. for 60 minutes to obtain a polyamide imide film (3) with a thickness of 50 μm.

<Example 4> [Preparation of polyamide imide resin (4)] Add TFMB and DMAc to a separable flask equipped with a stirring blade in a nitrogen atmosphere so that the solid content of TFMB becomes 5.39% by mass, and then add 11.11 mol% of 6FDAM to TFMB, and stir at room temperature. , While dissolving TFMB and 6FDAM in DMAc. Then, BPDA was added to the flask so that it might become 33.50 mol% with respect to TFMB, and it stirred at room temperature for 3 hours. Then, after cooling to 10°C, 4,4'-oxybis(benzyl chloride) (OBBC) was added so that it became 11.17 mol% relative to TFMB, and TPC was added so that it became 60.30 mol% relative to TFMB And stir for 30 minutes. Thereafter, the same amount of DMAc as the DMAc added for the first time was added, and after stirring for 10 minutes, TPC was added so as to be 6.70 mol% with respect to TFMB, and stirred for 2 hours. Then, 78.17 mol% of diisopropylethylamine and 4-picoline were added to the flask with respect to TFMB, and 234.51 mol% of acetic anhydride with respect to TFMB were added to the flask. After stirring for 30 minutes, the internal temperature was increased to 70°C. , And further stirred for 3 hours to obtain a reaction liquid. The obtained reaction liquid was cooled to room temperature, and was linearly thrown into a large amount of methanol, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Then, the precipitate was dried under reduced pressure at 60°C to obtain a polyimide resin (4).

[Manufacturing of polyimide film (4)] To the obtained polyimide resin (4), DMAc was added so that the concentration became 6.5% by mass to produce a polyimide varnish (4), and it was left at 25°C for 3 days. After that, the polyamide obtained by applying an applicator was applied to the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") so that the thickness of the self-supporting film became 42 μm. The amine varnish (4) was dried at 50°C for 30 minutes, and then at 140°C for 15 minutes to obtain a self-supporting film. The self-supporting film was fixed to the mold frame and dried at 200° C. for 60 minutes to obtain a polyamide imide film (4) with a thickness of 38 μm.

<Comparative example 1> [Preparation of polyimide resin (5)] Add TFMB and DMAc to a separable flask equipped with a stirring blade under a nitrogen atmosphere so that the solid content of TFMB becomes 5.36% by mass, and then add 11.11 mol% of 6FDAM to TFMB, and stir at room temperature. , While dissolving TFMB and 6FDAM in DMAc. Then, BPDA was added to the flask so that it might become 43.35 mol% with respect to TFMB, and it stirred at room temperature for 3 hours. Then, after cooling to 10 degreeC, TPC was added so that it might become 61.23 mol% with respect to TFMB, and it stirred for 30 minutes. Thereafter, the same amount of DMAc as the DMAc added for the first time was added, and after stirring for 10 minutes, TPC was added so as to be 6.80 mol% with respect to TFMB, and stirred for 2 hours. Then, 68.03 mol% of diisopropylethylamine and 4-picoline were added to the flask with respect to TFMB, and 317.46 mol% of acetic anhydride was added to TFMB. After stirring for 30 minutes, the internal temperature was raised to 70°C. , And further stirred for 3 hours to obtain a reaction liquid. The obtained reaction liquid was cooled to room temperature, and was linearly thrown into a large amount of methanol, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Then, the precipitate was dried under reduced pressure at 60°C to obtain a polyimide resin (5).

[Manufacturing of Polyimide Film (5)] To the obtained polyimide resin (5), DMAc was added so that the concentration became 9.0% by mass to prepare a polyimide varnish (5), which was left at 25°C for 3 days. When the stability was confirmed after 3 days, it became a gel state and lost fluidity, so it could not be applied and a film could not be obtained.

＜Comparative example 2＞ [Preparation of polyamide imide resin (6)] Add TFMB and DMAc to a separable flask equipped with a stirring blade under a nitrogen atmosphere so that the solid content of TFMB becomes 5.31% by mass, and then add 11.11 mol% of 6FDAM to TFMB, and stir at room temperature. , While dissolving TFMB and 6FDAM in DMAc. Then, BPDA was added to the flask so that it might become 46.30 mol% with respect to TFMB, and it stirred at room temperature for 3 hours. Then, after cooling to 10 degreeC, TPC was added so that it might become 62.50 mol% with respect to TFMB, and it stirred for 30 minutes. After that, the same amount of DMAc as the DMAc added for the first time was added, and after stirring for 10 minutes, TPC was added so as to be 6.94 mol% with respect to TFMB, and stirred for 2 hours. Then, 69.44 mol% of diisopropylethylamine and 4-picoline were added to the flask with respect to TFMB, and 324.07 mol% of acetic anhydride was added to TFMB. After stirring for 30 minutes, the internal temperature was raised to 70°C. , And further stirred for 3 hours to obtain a reaction liquid. The obtained reaction liquid was cooled to room temperature, and was linearly thrown into a large amount of methanol, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Then, the precipitate was dried under reduced pressure at 60°C to obtain a polyimide resin (6).

[Manufacturing of polyimide film (6)] To the obtained polyimide resin (6), DMAc was added so that the concentration became 8.0% by mass to prepare a polyimide varnish (6), and it was left at 25°C for 3 days. When the stability was confirmed after 3 days, it became a gel state and lost fluidity, so it could not be applied and a film could not be obtained.

<Comparative Example 3> [Preparation of polyamide imide resin (7)] Add TFMB and DMAc to a separable flask equipped with a stirring blade under a nitrogen atmosphere so that the solid content of TFMB becomes 4.89% by mass, and then add 11.11 mol% of 6FDAM to TFMB, and stir at room temperature. , While dissolving TFMB and 6FDAM in DMAc. Then, BPDA was added so that it might become 44.67 mol% with respect to TFMB, and it stirred at room temperature for 3 hours. Then, after cooling to 10 degreeC, TPC was added so that it might become 60.30 mol% with respect to TFMB, and it stirred for 30 minutes. Thereafter, the same amount of DMAc as the DMAc added for the first time was added, and after stirring for 10 minutes, TPC was added so as to be 6.70 mol% with respect to TFMB, and stirred for 2 hours. Then, 67.00 mol% of diisopropylethylamine and 4-picoline were added to the flask with respect to TFMB, and 312.67 mol% of acetic anhydride was added to TFMB. After stirring for 30 minutes, the internal temperature was raised to 70°C. , And further stirred for 3 hours to obtain a reaction liquid. The obtained reaction liquid was cooled to room temperature, and was linearly thrown into a large amount of methanol, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Then, the precipitate was dried under reduced pressure at 60°C to obtain a polyimide resin (7).

[Manufacturing of Polyimide Film (7)] To the obtained polyimide resin (7), DMAc was added so that the concentration became 8.0% by mass to prepare a polyimide varnish (7), and it was left at 25°C for 3 days. Thereafter, the polyamide obtained by applying an applicator was applied to the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") so that the thickness of the self-supporting film became 55 μm. Amine varnish (7) was dried at 50°C for 30 minutes, and then at 140°C for 15 minutes to obtain a self-supporting film. The self-supporting film was fixed to the mold frame, and then dried at 200° C. for 60 minutes to obtain a polyamide imide film (7) with a thickness of 50 μm.

<Example 5> [Preparation of polyamide imide resin (8)] Add TFMB and DMAc to a separable flask equipped with a stirring blade in a nitrogen atmosphere so that the solid content of TFMB becomes 4.65% by mass, and then add 25.00 mol% of 6FDAM to TFMB, and stir at room temperature. , While dissolving TFMB and 6FDAM in DMAc. Then, BPDA was added to the flask so that it might become 75.76 mol% with respect to TFMB, and it stirred at room temperature for 3 hours. Then, after cooling to 10 degreeC, TPC was added so that it might become 45.46 mol% with respect to TFMB, and it stirred for 30 minutes. After that, the same amount of DMAc as the DMAc added for the first time was added, and after stirring for 10 minutes, TPC was added so as to become 5.05 mol% with respect to TFMB, and stirred for 2 hours. Then, 50.51 mol% of diisopropylethylamine and 4-picoline were added to the flask with respect to TFMB, and 530.30 mol% of acetic anhydride was added to the flask with respect to TFMB. After stirring for 30 minutes, the internal temperature was raised to 70°C. , And further stirred for 3 hours to obtain a reaction liquid. The obtained reaction liquid was cooled to room temperature, and was linearly thrown into a large amount of methanol, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Then, the precipitate was dried under reduced pressure at 60°C to obtain a polyimide resin (8).

[Manufacturing of polyimide film (8)] To the obtained polyimide resin (8), DMAc was added so that the concentration became 6.5% by mass to prepare a polyimide varnish (8), and it was left at 25°C for 3 days. Thereafter, the polyamide obtained by applying an applicator was applied to the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") so that the thickness of the self-supporting film became 55 μm. Amine varnish (8) was dried at 50°C for 30 minutes, and then at 140°C for 15 minutes to obtain a self-supporting film. The self-supporting film was fixed to the mold frame and then dried at 200° C. for 60 minutes to obtain a polyamide imide film (8) with a thickness of 50 μm.

<Example 6> [Preparation of polyamide imide resin (9)] Add TFMB and DMAc to a separable flask equipped with a stirring blade under a nitrogen atmosphere so that the solid content of TFMB becomes 5.35 mass%, and then add 11.11 mol% of 6FDAM to TFMB, and stir at room temperature. , While dissolving TFMB and 6FDAM in DMAc. Then, BPDA was added to the flask so that it might become 34.01 mol% with respect to TFMB, and it stirred at room temperature for 3 hours. Then, after cooling to 10 degreeC, OBBC was added so that it might become 11.34 mol% with respect to TFMB, and TPC was added so that it might become 61.23 mol% with respect to TFMB, and it stirred for 30 minutes. Thereafter, the same amount of DMAc as the DMAc added for the first time was added, and after stirring for 10 minutes, TPC was added so as to be 6.80 mol% with respect to TFMB, and stirred for 2 hours. Then, 79.37 mol% of diisopropylethylamine and 4-picoline were added to the flask with respect to TFMB, and 238.10 mol% of acetic anhydride was added to the flask with respect to TFMB. After stirring for 30 minutes, the internal temperature was raised to 70°C. , And further stirred for 3 hours to obtain a reaction liquid. The obtained reaction liquid was cooled to room temperature, and was linearly thrown into a large amount of methanol, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Then, the precipitate was dried under reduced pressure at 60°C to obtain a polyimide resin (9).

[Manufacturing of Polyimide Film (9)] To the obtained polyimide resin (9), DMAc was added so that the concentration was 9.0% by mass to prepare a polyimide varnish (9), and it was left at 25°C for 3 days. Thereafter, the polyamide obtained by applying an applicator was applied to the smooth surface of a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") so that the thickness of the self-supporting film became 55 μm. Amine varnish (9) was dried at 50°C for 30 minutes, and then at 140°C for 15 minutes to obtain a self-supporting film. The self-supporting film was fixed to the mold frame, and then dried at 200° C. for 60 minutes to obtain a polyamide imide film (9) with a thickness of 50 μm.

According to the above method, the weight average molecular weight of the polyimide resin obtained in the examples and comparative examples, and the polyimide resin film (1) to (4) and (8) to (9) were measured. Elastic modulus, total light transmittance and varnish stability. The results obtained are shown in Table 1.

[Table 1] Mw Resin film Modulus of Elasticity [GPa] Total light transmittance (Tt)[%] Varnish stability after 3 days Example 1 556,000 (1) 6.7 90 ○ 2 555,000 (2) 6.4 90 ○ 3 409,000 (3) 6.7 90 ○ 4 469,000 (4) 6.7 90 ○ 5 461,000 (8) 5.8 90 ○ 6 360,000 (9) 6.0 90 ○ Comparative example 1 323,000 Cannot make film - - × 2 295,000 Cannot make film - - × 3 731,000 (7) 4.8 92 ○

According to Table 1, it is clear that the film system containing the polyamideimide resin of Examples 1 to 6 maintains a high total light transmittance and a film with a high elastic modulus. In addition, the stability of the varnish is also good. In contrast, the films containing the polyamide imide resins of Comparative Examples 1 and 2 in which the weight average molecular weight of the resin is relatively low had poor varnish stability and failed to form a film. In addition, the film containing the polyamide imide resin of Comparative Example 3 that does not include the structural unit (a1) represented by the formula (1) where Y in the formula (a) does not have a sufficient elastic modulus.

Claims (12)

A polyamide imine resin having at least a structural unit represented by formula (a) derived from a tetracarboxylic acid compound, a structural unit represented by formula (b) derived from a dicarboxylic acid compound, and a source From the structural unit represented by the formula (c) of the diamine compound: [化41]

[In formula (a), Y represents a tetravalent organic group, in formula (b), Z represents a divalent organic group, in formula (c), X represents a divalent organic group, and R ^c independently represents a hydrogen atom or a bond Bonding, * means bonding bond] and the Y in formula (a) is derived from formula (1): [化42]

[In the formula (1), R ^a each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, the alkoxy having 1 to 12 carbon atoms or the aryl group of 6 to 12, R ^a contained the Hydrogen atoms can be substituted with halogen atoms independently of each other, n represents an integer from 0 to 2, and * represents a bonding bond] The structural unit (a1) represented as the structural unit derived from the tetracarboxylic acid compound, the polyamide The weight average molecular weight of the imine-based resin converted from polystyrene is 330,000 or more. Such as the polyamide imine resin of claim 1, which comprises formula (2): [化43]

[In formula (2), Z ¹ represents a divalent aromatic group that may have a substituent, * represents a bonding bond] The structural unit (b1) represented as a structural unit derived from a dicarboxylic acid compound, and includes the formula ( 3): [化44]

[In formula (3), X ¹ represents a divalent aromatic group that may have a substituent, R ^c independently represents a hydrogen atom or a bonding bond, and * represents a bonding bond] The structural unit (c1) represented as the source From the structural unit of the diamine compound. Such as the polyamide imine resin of claim 2, wherein X ¹ in formula (3) is represented by formula (4): [化45]

[In formula (4), R ^b independently represents an alkyl group having 1 to 6 carbons, an aryl group having 6 to 12 carbons, or an alkoxy group having 1 to 6 carbons, and the hydrogen atom contained in R ^b It may be substituted with a halogen atom independently of each other, r each independently represents an integer of 1 to 4, and * represents a bonding bond]. For example, the polyimide imine resin of any one of claims 1 to 3, which contains Z in formula (b) is derived from formula (5): [化46]

[In formula (5), Ar ¹ independently represents a divalent aromatic group that may have a substituent, and V represents -O-, diphenylmethylene, linear or branched chain with 1 to 12 carbon atoms Or alicyclic divalent hydrocarbon group, -SO ₂ -, -S-, -CO- or -N(R ¹² )-, where the hydrogen atoms contained in the hydrocarbon group can be independently substituted with halogen atoms , R ¹² represents a hydrogen atom or an alkyl group with 1 to 12 carbon atoms which can be substituted by a halogen atom, and m represents an integer of 1 to 3, wherein when m is 2 or 3, multiple Vs may be the same , May be different, * represents a bonding bond] as the structural unit (b2) represented by the dicarboxylic acid compound, and/or includes the X in the formula (c) is represented by the formula (5) The structural unit (c2) is a structural unit derived from a diamine compound, and/or further includes Y in the formula (a) is derived from the formula (6): [化47]

[In formula (6), Ar ² independently represents a trivalent aromatic group which may have a substituent, s represents an integer of 0-2, Ar ¹ , V and * are as in the formula (5) Ar ¹ , V and * Defined, where the plural V and Ar ¹ existing when s is 2 may be the same as each other or different] The structural unit (a2) represented by the tetracarboxylic acid compound-derived structural unit. Such as the polyamide imine resin of claim 4, wherein formula (5) and formula (6) are represented by formula (7): [化48]

[In formula (7), R ¹ independently represents a hydrogen atom, a C 1-12 alkyl group, a C 1-12 alkoxy group, or a C 6-12 aryl group, which is contained in R ¹ Hydrogen atoms can be independently substituted with halogen atoms, R ^＊ represents R ¹ or bonding bond, ＊represents bonding bond, V represents -O-, diphenylmethylene, linear chain with carbon number 1-12 , Branched or alicyclic divalent hydrocarbon group, -SO ₂ -, -S-, -CO- or -N(R ¹² )-, where the hydrogen atoms contained in the hydrocarbon group can be mutually independently It is substituted with a halogen atom, and R ¹² represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms which may be substituted by a halogen atom]. Such as the polyamide imine resin of claim 5, wherein the formula (7) is derived from the formula (7'): [化49]

[In formula (7'), R ^* represents a hydrogen atom or a bonding bond, * represents a bonding bond] or formula (7"): [化50]

[In formula (7"), * represents a bonding bond]. The polyimide resin of any one of claims 1 to 6, wherein the formula (1) is represented by the formula (1'): [化51]

[＊Indicating bonding key]. A polyimide-based resin varnish comprising the polyimide-based resin according to any one of claims 1 to 7 and a solvent. An optical film comprising the polyimide-based resin according to any one of claims 1 to 7. A flexible display device provided with the optical film as claimed in claim 9. For example, the flexible display device of claim 10 further includes a touch sensor. For example, the flexible display device of claim 10 or 11 is further provided with a polarizing plate.