TW202007713A - Polyamideimide resin and optical film capable of forming an optical film having excellent light resistance - Google Patents

Abstract

The present invention provides a polyamideimide resin capable of forming an optical film having excellent light resistance. The polyamideimide resin of this invention comprises structural units represented by formula (1) and formula (2). In formula (1) and formula (2), X independently represents a divalent organic group; Y represents a tetravalent organic group; and Z represents a divalent heterocyclic ring.

Description

Polyamide imide resin and optical film

The present invention relates to a polyimide amide imide resin and an optical film that can form an optical film used as a front panel material or the like of an image display device, and a flexible display device provided with the optical film.

Image display devices such as liquid crystal display devices or organic EL (Electroluminescence) display devices are widely used for various purposes such as mobile phones or smart watches. The industry uses glass as the front panel of such an image display device, but because the glass is very rigid and easily breaks, it is difficult to use it as a front panel material such as a flexible display. As one of the materials to replace glass, the industry is constantly researching optical films formed from polyamidoamide resins (for example, Patent Document 1). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Special Publication No. 2015-521687

[Problems to be solved by the invention]

This type of optical film requires light resistance to prevent discoloration even when exposed to ultraviolet light. However, according to the research of the present inventors, if the previous optical film is exposed to ultraviolet light, the light resistance such as yellowness (YI) and other indicators indicating discoloration may change greatly, and the light resistance may be insufficient.

Therefore, an object of the present invention is to provide a polyimide amide imide resin and an optical film capable of forming an optical film having excellent light resistance, and a flexible display device provided with the optical film. [Technical means to solve the problem]

The inventors have made intensive studies to solve the above-mentioned problems and found that if the structural unit derived from a dicarboxylic acid compound having a divalent heterocycle is included as the structure derived from the dicarboxylic acid compound constituting the polyamidoamide resin, The unit can solve the above-mentioned problems and complete the present invention. That is, the following suitable aspects are included in the present invention.

[式(1)及式(2)中，X分別獨立地表示二價有機基，Y表示四價有機基，Z表示二價雜環]。 [2]如[1]中所記載之聚醯胺醯亞胺樹脂，其中於式(2)中，Z係含有硫原子之二價雜環。 [3]如[1]或[2]中所記載之聚醯胺醯亞胺樹脂，其中於式(2)中，Z為式(a)所表示之二價雜環： [化2]

[式(a)中，R^a 及R^b 分別獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基，R^a 及R^b 可相互鍵結，R^a 及R^b 中所含之氫原子可分別獨立地經鹵素原子取代，*表示鍵結鍵]。 [4]如[1]至[3]中任一項所記載之聚醯胺醯亞胺樹脂，其中式(2)所表示之結構單元之含量相對於式(1)所表示之結構單元1莫耳而言為0.1～10莫耳。 [5]一種光學膜，其係含有如[1]至[4]中任一項所記載之聚醯胺醯亞胺樹脂而成。 [6]一種光學膜，其包含含有式(1)及式(2b)所表示之結構單元之聚醯胺醯亞胺樹脂： [化3]

[式(1)及式(2b)中，X及L分別獨立地表示二價有機基，Y表示四價有機基]，且 波長420 nm下之透光率為70%以上，波長375 nm下之透光率為5%以下。 [7]如[6]中所記載之光學膜，其中光學膜中之紫外線吸收劑之含量相對於聚醯胺醯亞胺樹脂100質量份而言未達1質量份。 [8]如[6]或[7]中所記載之光學膜，其中於式(2b)中，L為二價雜環。 [9]一種可撓性顯示裝置，其具備如[5]中所記載之光學膜或如[6]至[8]中任一項所記載之光學膜。 [10]如[9]中所記載之可撓性顯示裝置，其進而具備觸控感測器。 [11]如[9]或[10]中所記載之可撓性顯示裝置，其進而具備偏光板。 [發明之效果][1] A polyimide amide imide resin, which comprises the structural units represented by formula (1) and formula (2): [Chem 1]

[In Formula (1) and Formula (2), X independently represents a divalent organic group, Y represents a tetravalent organic group, and Z represents a divalent heterocyclic ring]. [2] The polyamidoamide resin described in [1], wherein in formula (2), Z is a divalent heterocyclic ring containing a sulfur atom. [3] The polyamidoamide resin as described in [1] or [2], wherein in formula (2), Z is a divalent heterocyclic ring represented by formula (a): [Chem 2]

[In formula (a), R ^a and R ^b independently represent a hydrogen atom, a C 1-6 alkyl group, a C 1-6 alkoxy group or a C 6-12 aryl group, R ^a and R ^b may be bonded to each other, and the hydrogen atoms contained in R ^a and R ^b may be independently substituted by halogen atoms, respectively, * indicates a bonding bond]. [4] The polyimide amide imide resin as described in any one of [1] to [3], wherein the content of the structural unit represented by formula (2) relative to the structural unit 1 represented by formula (1) In terms of moles, it is 0.1 to 10 moles. [5] An optical film containing the polyamidoamide resin according to any one of [1] to [4]. [6] An optical film comprising a polyamidoamide resin containing structural units represented by formula (1) and formula (2b):

[In formula (1) and formula (2b), X and L independently represent a divalent organic group, and Y represents a tetravalent organic group], and the light transmittance at a wavelength of 420 nm is 70% or more, and at a wavelength of 375 nm The light transmittance is below 5%. [7] The optical film as described in [6], wherein the content of the ultraviolet absorber in the optical film is less than 1 part by mass with respect to 100 parts by mass of the polyamidoamide resin. [8] The optical film as described in [6] or [7], wherein in formula (2b), L is a divalent heterocyclic ring. [9] A flexible display device comprising the optical film as described in [5] or the optical film as described in any one of [6] to [8]. [10] The flexible display device as described in [9], which further includes a touch sensor. [11] The flexible display device described in [9] or [10], further including a polarizing plate. [Effect of invention]

The polyamidoamide resin of the present invention can form an optical film having excellent light resistance. In addition, the optical film of the present invention has excellent light resistance.

[式(1)及式(2)中，X分別獨立地表示二價有機基，Y表示四價有機基，Z表示二價雜環]。 含有本發明之聚醯胺醯亞胺樹脂而成之光學膜由於該聚醯胺醯亞胺樹脂包含式(2)所表示之結構單元，故而可具有優異之耐光性，可有效地抑制由紫外線之照射所引起之膜之變色。再者，於本說明書中，聚醯胺醯亞胺樹脂中之「結構單元」表示構成聚醯胺醯亞胺樹脂之重複結構單元。又，於本說明書中，所謂「耐光性」係指即便光學膜暴露於紫外光(紫外線區域之光)下亦可抑制變色之特性。<Polyamidimide resin> The polyamidimide resin of the present invention includes the structural units represented by formula (1) and formula (2):

[In Formula (1) and Formula (2), X independently represents a divalent organic group, Y represents a tetravalent organic group, and Z represents a divalent heterocyclic ring]. The optical film containing the polyimide amide imine resin of the present invention can have excellent light resistance and can effectively suppress ultraviolet rays because the polyimide amide imine resin contains the structural unit represented by formula (2) Discoloration of the film caused by the irradiation. In addition, in this specification, the "structural unit" in the polyamidoamide resin means a repeating structural unit constituting the polyamidoamide resin. In addition, in this specification, the term "light resistance" refers to the characteristic of suppressing discoloration even when the optical film is exposed to ultraviolet light (light in the ultraviolet region).

In formula (2), Z represents a divalent heterocyclic ring. Examples of the divalent heterocyclic ring include a heterocyclic ring containing at least one kind of hetero atom selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom as a constituent atom of the ring. In the bivalent heterocycle, part or all of the hydrogen atoms of the heterocycle may be substituted with a substituent. Examples of the substituent include an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and a halogen atom. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, the aryl group having 6 to 12 carbon atoms or a halogen atom include the carbon number 1 in R ^a and R ^b of the formula (a) Examples of the alkyl group of -6, the alkoxy group of 1 to 6 carbon atoms, the aryl group of 6 to 12 carbon atoms or halogen atoms. The bivalent heterocyclic ring may be monocyclic or polycyclic. In the case of polycyclic, it may be a condensed heterocyclic ring formed by condensing a plurality of heterocyclic rings, or a condensed heterocyclic ring formed by condensing a heterocyclic ring and a hydrocarbon ring. ring. Heterocycles can be non-aromatic, usually aromatic. The heterocyclic ring in the monocyclic structure or the multicyclic ring structure composed of a plurality of rings is preferably a 4 to 15 member ring, more preferably a 4 to 10 member ring, and further preferably 4 ~ 6-member ring. In one aspect of the present invention, the polyamidoamide resin may contain a plurality of Zs that are the same or different.

Examples of the divalent heterocyclic ring constituting Z include a sulfur atom-containing heterocyclic ring such as a thiophene ring, a tetrahydrothiophene ring, a thioanthracene ring, a thiazole ring, a thiadiazole ring, and a thiophene ring, and the direct bond is removed. A bivalent heterocyclic ring containing a sulfur atom derived from two hydrogen atoms among carbon atoms constituting a ring or a hydrogen atom of a heteroatom; from chroman ring, chroman ring, furan ring, isobenzo ring Heterocyclic rings containing oxygen atoms, such as furan rings, coffee rings, etc., divalent heterocyclic rings containing oxygen atoms obtained by removing two hydrogen atoms directly bonded to the hydrogen atoms of carbon atoms or hetero atoms constituting the ring; from pyrrole Heterocyclic rings containing nitrogen atoms, such as rings, imidazole rings, pyridine rings, indole rings, quinoline rings, carbazole rings, acridine rings, piperidine rings, piper rings, ring rings, etc., are directly bonded to the constituent rings The two hydrogen atoms of the hydrogen atom of the carbon atom or the hetero atom of the carbon atom contain a nitrogen atom. These divalent heterocycles constituting Z can be used alone or in combination of two or more. Among these, from the viewpoint of easily improving the light resistance of the optical film, a divalent heterocyclic ring containing a sulfur atom is preferred, and a divalent heteroaromatic ring containing a sulfur atom is more preferred.

[式(a)中，R^a 及R^b 分別獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基，R^a 及R^b 可相互鍵結，R^a 及R^b 中所含之氫原子可分別獨立地經鹵素原子取代，*表示鍵結鍵]。 若Z為式(a)所表示之二價雜環，則含有本發明之聚醯胺醯亞胺樹脂而成之光學膜可進一步提高耐光性。In a preferred aspect of the present invention, in formula (2), Z is a divalent heterocyclic ring represented by formula (a): [化5]

[In formula (a), R ^a and R ^b independently represent a hydrogen atom, a C 1-6 alkyl group, a C 1-6 alkoxy group or a C 6-12 aryl group, R ^a and R ^b may be bonded to each other, and the hydrogen atoms contained in R ^a and R ^b may be independently substituted by halogen atoms, respectively, * indicates a bonding bond]. If Z is a divalent heterocyclic ring represented by the formula (a), the optical film containing the polyamidoamide resin of the present invention can further improve light resistance.

R ^a and R ^b independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, second butyl, third butyl, n-pentyl, and 2-methyl. -Butyl, 3-methylbutyl, 2-ethyl-propyl, 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. And, R ^a and R ^b may be bonded to each other (coupling), in the case when, as a group R ^a and R ^b are formed of, include: ethylenedioxy-stretched, stretch propylenedioxy, dimethyl Extend propyl dioxy and so on. Examples of the aryl group having 6 to 12 carbon atoms include phenyl, tolyl, xylyl, naphthyl, and biphenyl. Viewpoint of the light resistance of the optical film obtained easily improved in terms of, R ^a and R ^b are each independently preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, the carbon atoms, or an aryl group of 6 to 12, more It is preferably a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an aryl group having 6 to 8 carbon atoms, and more preferably a hydrogen atom, a methyl group, an ethyl group, or a phenyl group. Here, the hydrogen atoms contained in R ^a and R ^b may be independently substituted by halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

In formula (1) and formula (2), X independently represents a divalent organic group, preferably a divalent organic group having a carbon number of 4 to 40, and more preferably a carbon number having a cyclic structure of 4 to 4 40 divalent organic radical. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. In the above organic group, the hydrogen atom in the organic group may be substituted with a hydrocarbon group or a hydrocarbon group substituted with fluorine. In this case, the carbon number of the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably 1-8. The polyimide amide imine resin, which is one embodiment of the present invention, may include a plurality of types of X, and the plurality of types of X may be the same or different from each other. As X, there can be exemplified: formula (10), formula (11), formula (12), formula (13), formula (14), formula (15), formula (16), formula (17) and formula (18) The represented group; the group represented by these formulas (10) to (18) in which the hydrogen atom is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and a chain formula having a carbon number of 6 or less Hydrocarbyl.

[化6]

In formula (10) to formula (18), * represents a bonding bond, and V ¹ , V ² and V ³ each independently represent a single bond, -O-, -S-, -CH ₂ -and -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -CO- or -NQ. Here, Q represents a C1-C12 hydrocarbon group which may be substituted with a halogen atom. In one example, V ¹ and V ³ are single bonds, -O- or -S-, and V ² is -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, or -SO ₂ -. The bonding positions of V ¹ and V ² to each ring, and the bonding positions of V ² and V ³ to each ring are respectively relative to each ring, preferably meta or para, more preferably para.

Among the bases represented by formulas (10) to (18), from the viewpoint of easy increase in light resistance, surface hardness, bending resistance, and elastic modulus of the optical film, formula (13) and formula are preferred The bases represented by formula (15), formula (15), formula (16) and formula (17) are more preferably those represented by formula (14), formula (15) and formula (16). In addition, regarding V ¹ , V ² and V ³ , from the viewpoint of easy increase in light resistance, surface hardness, flexibility, etc. of the optical film, it is preferably independently a single bond, -O- or -S-, respectively. The best is a single bond or -O-.

[式(4)中，R¹⁰ ～R¹⁷ 分別獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基，R¹⁰ ～R¹⁷ 中所含之氫原子可分別獨立地經鹵素原子取代，*表示鍵結鍵] 。 若式(1)及式(2)中之複數個X之至少一部分為式(4)所表示之基，則光學膜容易提高耐光性、彈性模數及彎曲性等。In a suitable embodiment of the present invention, at least a part of the plurality of X in formula (1) and formula (2) is the base represented by formula (4): [化7]

[In formula (4), R ¹⁰ to R ¹⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and R ¹⁰ to The hydrogen atoms contained in R ¹⁷ may each be independently substituted with a halogen atom, and * represents a bonding bond]. If at least a part of the plurality of Xs in the formula (1) and the formula (2) is the base represented by the formula (4), the optical film easily improves light resistance, elastic modulus, bendability, and the like.

In formula (4), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ , and R ¹⁷ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and a carbon number 1 ~6 alkoxy or C6-12 aryl. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, or the aryl group having 6 to 12 carbon atoms include those having 1 to 6 carbon atoms in R ^a and R ^b of the formula (a) Examples of the alkyl group, the alkoxy group having 1 to 6 carbon atoms or the aryl group having 6 to 12 carbon atoms. R ¹⁰ to R ¹⁷ are each independently preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Here, R ¹⁰ to R ¹⁷ The hydrogen atoms contained can be independently replaced by halogen atoms. Examples of the halogen atom include those exemplified as the halogen atoms in R ^a and R ^b of the formula (a). From the viewpoint of easily increasing the light resistance, surface hardness, transparency, etc. of the optical film, R ¹⁰ to R ¹⁷ are each independently further preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group, or a trifluoromethyl group, particularly Preferably, R ¹⁰ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , and R ¹⁶ are hydrogen atoms, and R ¹¹ and R ¹⁷ are hydrogen atoms, methyl groups, fluoro groups, chloro groups, or trifluoromethyl groups, particularly preferably R ¹¹ and R ¹⁷ are methyl or trifluoromethyl.

所表示之基，即，複數個X之至少一部分為式(4')所表示之基。於該情形時，光學膜有容易提高耐光性、彈性模數及透明性等之傾向，同時亦可利用含有氟元素之骨架提高聚醯胺醯亞胺樹脂於溶劑中之溶解性，將樹脂清漆之黏度抑制為較低而使膜之加工性變得較容易。In a suitable embodiment of the present invention, the base represented by formula (4) is formula (4'): [化8]

The represented base, that is, at least a part of the plurality of Xs is represented by the formula (4'). In this case, the optical film tends to easily improve light resistance, elastic modulus, transparency, etc. At the same time, the skeleton containing fluorine element can also be used to improve the solubility of the polyamidoamide resin in the solvent, and the resin varnish The viscosity is suppressed to be low, making the processability of the film easier.

In a suitable embodiment of the present invention, X in the polyamidoamide resin is preferably 30 mol% or more, more preferably 50 mol% or more, and further preferably 70 mol% or more It is represented by formula (4), especially formula (4'). If X in the above range in the polyamidoamide resin is represented by formula (4), especially formula (4'), the optical film tends to easily improve light resistance, elastic modulus and transparency, and The skeleton containing fluorine element can also be used to improve the solubility of the polyamidoamide resin in the solvent, to suppress the viscosity of the resin varnish to be low, and to make the processability of the film easier. Furthermore, it is preferable that 100 mol% or less of X in the above-mentioned polyamidoamide resin is represented by formula (4), especially formula (4'). X in the above-mentioned polyimide amide imide resin may be the formula (4), especially (4'). The ratio of the group represented by the formula (4) of X in the above-mentioned polyimide amide imine resin can be measured, for example, using ¹ H-NMR (Nuclear Magnetic Resonance, nuclear magnetic resonance), or can be calculated based on the addition ratio of the raw materials .

In formula (1), Y independently represents a tetravalent organic group, preferably a tetravalent organic group having a carbon number of 4 to 40, more preferably a tetravalent organic group having a carbon number of 4 to 40 having a cyclic structure base. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. The above-mentioned organic group is an organic group in which a hydrogen atom in the organic group may be substituted with 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. The polyimide amide imine resin, which is one embodiment of the present invention, may include a plurality of types of Y, and the plurality of types of Y may be the same as or different from each other. As Y, there can be exemplified the following formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula ( 28) and the groups represented by the formula (29); groups in which the hydrogen atoms in the groups represented by the formulas (20) to (29) are substituted with methyl, fluoro, chloro or trifluoromethyl; and A chain hydrocarbon group with a tetravalent carbon number of 6 or less.

[化9]

In formula (20) to formula (29), * represents a bonding bond, and 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-, -SO ₂ -, -CO-, -O-Ar-O-, -Ar-O-Ar-, -Ar-CH ₂ -Ar-, -Ar-C(CH ₃ ) ₂ -Ar- or -Ar-SO ₂ -Ar-. Ar represents a C 6-20 arylene group in which a hydrogen atom can be substituted with a fluorine atom, and specific examples include phenylene group.

Among the bases represented by formulas (20) to (29), from the viewpoint that the light resistance, bendability, surface hardness, and transparency of the optical film are easily increased, the formulas (26) and (28) are preferred ) Or the base represented by formula (29), more preferably the base represented by formula (26). In addition, from the viewpoint that the flexibility is easily increased and the yellowness (YI value) is easily decreased, W ¹ is preferably a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, respectively. , -CH(CH ₃ )-, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -, more preferably single bond, -O-, -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -, further preferably a single bond, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -.

[式(5)中，R¹⁸ ～R²⁵ 分別獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基，R¹⁸ ～R²⁵ 中所含之氫原子可分別獨立地經鹵素原子取代，*表示鍵結鍵]。 若式(1)中之複數個Y之至少一部分為式(5)所表示之基，則光學膜有容易提高耐光性、彎曲性、及透明性等之傾向，同時亦可提高聚醯胺醯亞胺樹脂於溶劑中之溶解性，將樹脂清漆之黏度抑制為較低而使膜之加工性變得較容易。In a suitable embodiment of the present invention, at least a part of the plurality of Y in formula (1) is the base represented by formula (5): [化10]

[In formula (5), R ¹⁸ to R ²⁵ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and R ¹⁸ to The hydrogen atoms contained in R ²⁵ may be independently substituted by halogen atoms, and * represents a bond]. If at least a part of the plurality of Y in formula (1) is the base represented by formula (5), the optical film tends to easily improve light resistance, flexibility, transparency, etc. At the same time, it can also increase the polyamide The solubility of the imine resin in the solvent suppresses the viscosity of the resin varnish to be low, making the processability of the film easier.

In formula (5), R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ , and R ²⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, and 1 to 1 carbon atoms. An alkoxy group of 6 or an aryl group having 6 to 12 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, or the aryl group having 6 to 12 carbon atoms include those having 1 to 6 carbon atoms in R ^a and R ^b of the formula (a) Examples of the alkyl group, the alkoxy group having 1 to 6 carbon atoms or the aryl group having 6 to 12 carbon atoms. R ¹⁸ to R ²⁵ are each independently preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. Here, R ¹⁸ to R ²⁵ The hydrogen atoms contained can be independently replaced by halogen atoms. Examples of the halogen atom include those exemplified as the halogen atoms in R ^a and R ^b of the formula (a). From the viewpoint of easily increasing the light resistance, flexibility, transparency, etc. of the optical film, R ¹⁸ to R ²⁵ are each independently more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group, or a trifluoromethyl group. Preferably, R ¹⁸ , R ¹⁹ , R ²⁰ , R ²³ , R ²⁴ , and R ²⁵ are hydrogen atoms, and R ²¹ and R ²² are hydrogen atoms, methyl groups, fluoro groups, chloro groups, or trifluoromethyl groups, particularly preferably R ²¹ and R ²² are methyl or trifluoromethyl.

所表示之基，即，複數個Y之至少一部分為式(5')所表示之基。於該情形時，容易提高光學膜之耐光性、表面硬度及透明性等。In a suitable embodiment of the present invention, the base represented by formula (5) is formula (5'): [Chem 11]

The base represented, that is, at least a part of the plurality of Y is the base represented by formula (5'). In this case, it is easy to improve the light resistance, surface hardness and transparency of the optical film.

In a suitable embodiment of the present invention, the Y of the polyamidoamide resin is preferably 50 mol% or more, more preferably 60 mol% or more, and further preferably 70 mol% or more. Formula (5), especially formula (5'). If Y in the above-mentioned range in the above-mentioned polyamidoamide resin is represented by formula (5), especially formula (5'), the optical film containing the polyamidoamide resin has light resistance, Transparency, flexibility, etc. tend to increase easily, and the solubility of the polyamidoimide resin in the solvent can be improved by the skeleton containing fluorine element, the viscosity of the resin varnish is suppressed to be low, and the film is easy to carry out Of manufacturing. In addition, it is preferable that 100 mol% or less of Y in the above-mentioned polyamidoamide resin is represented by formula (5), especially formula (5'). Y in the above-mentioned polyamide amide imide resin may be the formula (5), especially (5'). The ratio of the group represented by formula (5) of Y in the above-mentioned polyamide amide imide resin can be measured using ¹ H-NMR, for example, or can be calculated based on the addition ratio of raw materials.

In a suitable embodiment of the present invention, in the polyamidoamide resin of the present invention, the content of the structural unit represented by formula (2) is 1 mole relative to the structural unit represented by formula (1) In particular, it is 0.1 moles or more, more preferably 0.5 moles or more, and further preferably 1.0 moles or more, particularly preferably 1.5 moles or more, and preferably 10.0 moles or less, more preferably 6.0 moles or less, Furthermore, it is preferably 5.0 moles or less, particularly preferably 4.5 moles or less, and any combination of the upper limit and the lower limit may be used. If the content of the structural unit represented by formula (2) is more than the above lower limit, the optical film tends to exhibit higher light resistance. In addition, if the content of the structural unit represented by formula (2) is below the upper limit, the viscosity increase caused by the hydrogen bond between the amide bond in formula (2) can be suppressed, and the viscosity of the varnish can be reduced, thereby making the optical The manufacture of the membrane becomes easy. In addition, the content (ratio) of the structural unit represented by Formula (2) in the polyamidoamide resin can be measured using ¹ H-NMR, for example, or can be calculated based on the addition ratio of the raw materials.

[式(2a)中，X及K分別獨立地表示二價有機基。其中，K不含雜環]。The polyamidoamide resin of the present invention may further contain the structural unit represented by formula (2a): [Chem 12]

[In formula (2a), X and K each independently represent a divalent organic group. Among them, K does not contain heterocycle].

In formula (2a), K is independently a divalent organic group, preferably representing a carbon number of 4-40 which may be substituted by a hydrocarbon group of 1 to 8 carbon atoms or a hydrocarbon group of 1 to 8 carbon atoms substituted by fluorine The organic group is more preferably a cyclic structure having a carbon number of 4 to 40 which may be substituted with a hydrocarbon group having 1 to 8 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or a hydrocarbon group having 1 to 8 carbon atoms substituted with fluorine. Divalent organic radical. Examples of the cyclic structure include alicyclic and aromatic ring structures. As the organic group of K, formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula ( 28) Among the bonding bonds of the groups represented by the formula (29), two groups that are not adjacent to each other are substituted with hydrogen atoms and a divalent chain hydrocarbon group having a carbon number of 6 or less. From the viewpoint of easily suppressing the yellowness of the optical film (reducing the YI value), the bases represented by formulas (22) and (26) and formula (29) are preferred, and further preferably formulas (26) and (28) ), formula (29). In one embodiment of the present invention, the polyamidoamide resin may contain plural kinds of K, and the plural kinds of K may be the same or different from each other.

(式(3)中，R¹ ～R⁸ 分別獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基，R¹ ～R⁸ 中所含之氫原子可分別獨立地經鹵素原子取代，A表示單鍵、-O-、-CH₂ -、-CH₂ -CH₂ -、-CH(CH₃ )-、-C(CH₃ )₂ -、-C(CF₃ )₂ -、-SO₂ -、-S-、-CO-或-N(R⁹ )-，R⁹ 表示氫原子、可經鹵素原子取代之碳數1～12之烴基，m為0～4之整數，*表示鍵結鍵)。In a suitable embodiment of the present invention, from the viewpoint of easily improving the light resistance, elastic modulus, surface hardness, etc. of the optical film, at least a part of K in formula (2a) preferably includes formula (3) The expressed basis: [Chem 13]

(In formula (3), R ¹ to R ⁸ each independently represent a hydrogen atom, a C 1-6 alkyl group, a C 1 to 6 alkoxy group, or a C 6 to 12 aryl group, and R ¹ to The hydrogen atoms contained in R ⁸ may be independently substituted with halogen atoms, A represents a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C( CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -S-, -CO- or -N(R ⁹ )-, R ⁹ represents a hydrogen atom, the number of carbons that can be substituted by a halogen atom Hydrocarbon group of 1-12, m is an integer of 0-4, * represents a bonding bond).

In formula (3), A independently represents a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -,- C(CF ₃ ) ₂ -, -SO ₂ -, -S-, -CO-, or -N(R ⁹ )-, from the viewpoint of easily improving the light resistance, elastic modulus, surface hardness, etc. of the optical film, Preferably, it means -O- or -S-, more preferably it means -O-. R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group or carbon having 1 to 6 carbon atoms Numbers 6 to 12 aryl groups. Examples of the alkyl group having 1 to 6 carbon atoms, the alkoxy group having 1 to 6 carbon atoms, or the aryl group having 6 to 12 carbon atoms include those having 1 to 6 carbon atoms in R ^a and R ^b of the formula (2) The alkyl group, alkoxy group having 1 to 6 carbon atoms or aryl group having 6 to 12 carbon atoms are exemplified above. From the viewpoint of easily improving the light resistance, elastic modulus, surface hardness, etc. of the optical film, R ¹ to R ⁸ each independently preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably represent hydrogen The atom or the alkyl group having 1 to 3 carbon atoms more preferably represents a hydrogen atom. Here, the hydrogen atoms contained in R ¹ to R ⁸ may each be independently substituted with a halogen atom. R ⁹ represents a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom. In addition, as X, those exemplified in the above as X of the formula (1) and the formula (2) can be cited.

In formula (3), m is an integer in the range of 0 to 4. If m is in this range, the light resistance, elastic modulus, surface hardness, etc. of the optical film tend to be good. In addition, in formula (3), m is preferably an integer in the range of 0 to 3, more preferably an integer in the range of 0 to 2, and further preferably 0 or 1, particularly preferably 1. If m is within this range, the light resistance, elastic modulus, surface hardness, etc. of the optical film tend to become good, and the availability of raw materials is relatively good. Furthermore, K may contain one or two or more of the groups represented by the formula (3), and from the viewpoint of easier improvement of light resistance, elastic modulus, surface hardness, etc. of the optical film, it is more preferable to include m of 1. base.

所表示之基，即，複數個K之至少一部分為式(3')所表示之基。於該情形時，光學膜更容易提高耐光性、彈性模數及表面硬度等。In a suitable embodiment of the present invention, formula (3) is formula (3'): [Chem 14]

The base represented, that is, at least a part of the plurality of Ks is the base represented by the formula (3'). In this case, it is easier for the optical film to improve light resistance, elastic modulus, surface hardness, and the like.

In a suitable embodiment in which the polyimide amide imine resin of the present invention includes the group represented by formula (3), m of formula (3) is 0 to 4, preferably 1 to 4 The content is relative to the structural unit represented by the formula (1), the structural unit represented by the formula (2), and the structural unit represented by the formula (2a) [hereinafter, the existence is represented by the formula (1) to the formula (2a) In the case of structural units], the total molar amount is preferably 3 mol% or more, more preferably 5 mol% or more, and further preferably 7 mol% or more, and particularly preferably 9 mol% or more It is preferably 90 mol% or less, more preferably 70 mol% or less, and further preferably 50 mol% or less, and particularly preferably 30 mol% or less, which can be any combination of these upper and lower limits. If m in formula (3) is 0 to 4, preferably 1 to 4, the base represented by the above lower limit is greater than the lower limit, the optical film easily improves light resistance, elastic modulus, surface hardness, and the like. If m of formula (3) is a group represented by 1 to 4 below the upper limit, the viscosity of the resin varnish can be suppressed by suppressing the thickening caused by the hydrogen bond between the amide bonds derived from formula (3) , Can make the processing of optical film easy.

In a suitable embodiment of the present invention, the content of the structural unit represented by formula (2) in the polyamidoamide resin is relative to the total content of the structural units represented by formula (1) to formula (2a) In terms of ear volume, it is preferably 20 mol% or more, more preferably 30 mol% or more, and further preferably 40 mol% or more, particularly preferably 50 mol% or more, and most preferably 60 mol% or more And preferably 90 mol% or less, more preferably 85 mol% or less, and further preferably 80 mol% or less, which can be any combination of these upper and lower limits. If the structural unit represented by the formula (2) in the polyamidoamide resin is within the above range, it is easier to improve the light resistance of the optical film.

The polyamidoamide resin may further include the structural unit represented by formula (30) and/or the structural unit represented by formula (31). [化15]

In formula (30), Y ^{1 is} independently a tetravalent organic group, preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. As Y ¹ , there can be exemplified: formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) ) And the group represented by formula (29), the group in which the hydrogen atom in the groups represented by these formulas (20) to (29) is substituted with methyl, fluoro, chloro or trifluoromethyl, and A chain hydrocarbon group with a valence carbon number of 6 or less. The polyimide amide imine resin, which is one embodiment of the present invention, may include a plurality of Y ¹ , and the plurality of Y ¹ may be the same as or different from each other.

In formula (31), Y ² is a trivalent organic group, preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. As Y ² , there can be exemplified: formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula (28) ) And any of the bonding bonds of the group represented by formula (29) is substituted with a hydrogen atom group and a trivalent carbon number 6 or less chain hydrocarbon group. The polyimide amide imine resin, which is one embodiment of the present invention, may contain plural kinds of Y ² , and plural plural kinds of Y ² may be the same or different from each other.

In Formula (30) and Formula (31), X ¹ and X ² are each independently a divalent organic group, preferably an organic group in which a hydrogen atom in the organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. As X ¹ and X ² , there can be exemplified: formula (10), formula (11), formula (12), formula (13), formula (14), formula (15), formula (16), formula (17), And the group represented by the formula (18); the group in which the hydrogen atom in the groups represented by the formulas (10) to (18) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and the number of carbons Chain hydrocarbon groups below 6.

In one embodiment of the present invention, in addition to the structural units represented by formula (1) and formula (2), the polyamidoamide resin includes, as needed, structural units and formulas selected from formula (2a) At least one structural unit among the structural unit represented by (30) and the structural unit represented by formula (31). From the viewpoint of easily improving the light resistance of the optical film, the total content of the structural units represented by the formula (1) to the formula (2a) in the above-mentioned polyamide amide imide resin is based on the composition of the polyamide amide imide The total molar amount of all structural units of the resin is preferably 80 mol% or more, more preferably 90 mol% or more, and further preferably 95 mol% or more, particularly preferably 99 mol% or more, usually Below 100%. In addition, the content (ratio) of the structural unit represented by Formula (1)-Formula (2a) can be measured using ¹ H-NMR, for example, or can be calculated based on the addition ratio of raw materials.

Regarding the weight average molecular weight (Mw) of polyamidimide resin, calculated in terms of standard polystyrene, it is preferably 100,000 or more, more preferably 150,000 or more, still more preferably 200,000 or more, particularly preferably 250,000 or more, especially It is 300,000 or more, and preferably 1,000,000 or less, more preferably 900,000 or less, and can be any combination of these upper and lower limits. If the Mw of the polyimide amide imide resin is above the lower limit, the flexibility, surface hardness, elastic modulus, etc. of the optical film are easily improved, and if it is below the upper limit, the gel of the resin varnish is easily suppressed. The transparency and appearance of the obtained polyimide amide imide resin tend to be good. Furthermore, Mw can be measured by gel permeation chromatography (GPC), for example, by the method described in the examples.

<Manufacturing method of polyimide amide imine resin> The polyimide amide imine resin of the present invention can be produced by using a tetracarboxylic acid compound, a dicarboxylic acid compound, and a diamine compound as main raw materials, for example, a polymer including a structural unit represented by formula (1) and formula (2) The amide imide resin can be produced by a method including the steps of: reacting the diamine compound represented by the formula (6) with the tetracarboxylic acid compound represented by the formula (7) to produce a polyamino acid; The step of reacting the polyamic acid with the dicarboxylic acid compound represented by formula (8) to form a polyamidoamide imine precursor; the step of imidizing the polyamidoamide imine precursor.

[式(6)、式(7)及式(8)中，X與式(1)及式(2)中之X相對應，Y與式(1)中之Y相對應，Z與式(2)中之Z相對應，R^c 及R^d 分別獨立地為-OH、-OMe、-OEt、-OPr、-OBu或-Cl][Chem 16]

[In formula (6), formula (7) and formula (8), X corresponds to X in formula (1) and formula (2), Y corresponds to Y in formula (1), and Z corresponds to formula ( 2) Corresponding to Z in R, R ^c and R ^d are independently -OH, -OMe, -OEt, -OPr, -OBu or -Cl]

[式(9)中，K與式(2a)中之K相對應，R^e 及R^f 分別獨立地為-OH、-OMe、-OEt、-OPr、-OBu或-Cl]In the above production method, as the dicarboxylic acid compound, if the dicarboxylic acid compound represented by formula (9) is further used, a polyamidoamide containing the structural unit represented by formula (1) to formula (2a) can be produced Imine resin. [化17]

[In the formula (9), and K in the formula (. 2A) corresponding to a K, R ^e, and R ^f are each independently -OH, -OMe, -OEt, -OPr, -OBu or -CI]

Specifically, examples of the diamine compound include aliphatic diamines, aromatic diamines, and mixtures of these. In addition, in this embodiment, the "aromatic diamine" means a diamine in which an amine group is directly bonded to an aromatic ring, and an aliphatic group or other substituent may be included in a part of its structure. The aromatic ring may be a single ring or a condensed ring, and examples include benzene ring, naphthalene ring, anthracene ring, and stilbene ring. But it is not limited to these. Among these, a benzene ring is preferred. In addition, the "aliphatic diamine" means a diamine in which an amine group is directly bonded to an aliphatic group, and may include an aromatic ring or other substituents in a part of its structure. The diamine compound can be used alone or in combination of two or more.

Specific examples of the aliphatic diamine include non-cyclic aliphatic diamines such as hexamethylene diamine; 1,3-bis(aminomethyl)cyclohexane, and 1,4-bis(amino Cycloaliphatic diamines such as methyl) cyclohexane, noranediamine, 4,4'-diaminodicyclohexylmethane, etc. These can be used alone or in combination of two or more.

Specific examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, and 1,5-diaminonaphthalene , 2,6-diaminonaphthalene and other aromatic diamines with one aromatic ring; 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4' -Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'- Diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy) )Benzene, 4,4'-diaminodiphenyl sulfone, bis[4-(4-aminophenoxy)phenyl] benzene, bis[4-(3-aminophenoxy)phenyl]碸, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2' -Dimethylbenzidine, 2,2'-bis(trifluoromethyl)benzidine (sometimes also expressed as TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, 9, 9-bis(4-aminophenyl) stilbene, 9,9-bis(4-amino-3-methylphenyl) stilbene, 9,9-bis(4-amino-3-chlorophenyl) Aromatic diamines with 2 or more aromatic rings, such as stilbene, 9,9-bis(4-amino-3-fluorophenyl) stilbene. These can be used alone or in combination of two or more.

As the aromatic diamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,3' are preferred -Diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 1,4-bis(4-aminophenoxy)benzene, Bis[4-(4-aminophenoxy)phenyl] satin, bis[4-(3-aminophenoxy)phenyl] satin, 2,2-bis[4-(4-aminobenzene Oxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoro Methyl)-4,4'-diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4, 4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 1,4-bis(4-aminophenoxy) Benzene, bis[4-(4-aminophenoxy)phenyl] ash, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-dimethyl Benzidine, 2,2'-bis (trifluoromethyl) benzidine, 4,4'-bis (4-aminophenoxy) biphenyl. These can be used alone or in combination of two or more.

Among the above diamine compounds, from the viewpoint of easily improving the light resistance, surface hardness, or transparency of the optical film, it is preferable to use one or more kinds selected from the group consisting of aromatic diamines having a biphenyl structure . More preferably, it is selected from 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)benzidine, 4,4'-bis(4-aminophenoxy)biphenyl and One or more types of 4,4'-diaminodiphenyl ether are used, and 2,2'-bis(trifluoromethyl)benzidine is preferably used.

The tetracarboxylic acid compound means a tetracarboxylic acid or a tetracarboxylic acid derivative. Examples of the tetracarboxylic acid derivatives include anhydrides of tetracarboxylic acids, preferably diacid anhydride, and chloroform. Examples of the tetracarboxylic acid compounds include aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic acids and their anhydrides, preferably dianhydrides, and aliphatic tetracarboxylic acids and their anhydrides, preferably fatty acids such as dianhydrides. Group tetracarboxylic acid compounds and so on. These tetracarboxylic acid compounds can be used alone or in combination of two or more.

Specific examples of the aromatic tetracarboxylic dianhydride include non-condensed polycyclic aromatic tetracarboxylic dianhydride, monocyclic aromatic tetracarboxylic dianhydride and condensed polycyclic aromatic tetracarboxylic dianhydride Acid dianhydride. Examples of the non-condensed polycyclic aromatic tetracarboxylic dianhydride include 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride Anhydride, 2,2',3,3'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride (sometimes also expressed as BPDA), 2, 2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylbenzene tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl) ) Propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4' -(Hexafluoroisopropylidene)diphthalic dianhydride (sometimes also expressed 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-dicarboxyphenyl) Ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, 4,4'-(p-phenylene dioxy) di Phthalic dianhydride and 4,4'-(m-phenylene dioxy) diphthalic dianhydride. In addition, examples of monocyclic aromatic tetracarboxylic dianhydride include 1,2,4,5-benzenetetracarboxylic dianhydride, and examples of condensed polycyclic aromatic tetracarboxylic dianhydride include 2. 3,6,7-Naphthalenetetracarboxylic dianhydride.

Among these, preferably, 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2,2', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride , 3,3',4,4'-diphenyl ash tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3- Dicarboxyphenyl) propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic acid di Anhydride, 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 dianhydride, bis(2 ,3-dicarboxyphenyl)methane dianhydride, 4,4'-(p-phenylene dioxy) diphthalic dianhydride and 4,4'-(m-phenylene dioxy) di-ortho Phthalic dianhydride, more preferably: 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3 ,3'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride and 4, 4'-(p-phenylene dioxy) diphthalic dianhydride. These can be used alone or in combination of two or more.

Examples of the aliphatic tetracarboxylic dianhydride include cyclic or acyclic aliphatic tetracarboxylic dianhydride. The so-called cycloaliphatic tetracarboxylic dianhydride is a tetracarboxylic dianhydride having an alicyclic hydrocarbon structure. Specific examples thereof include: 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1 , 2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride and other cycloalkane tetracarboxylic dianhydride, bicyclo[2.2.2]oct-7 -Ene-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl-3,3',4,4'-tetracarboxylic dianhydride and positional isomers of these. These can be used alone or in combination of two or more. Specific examples of the non-cyclic aliphatic tetracarboxylic dianhydride include 1,2,3,4-butane tetracarboxylic dianhydride, 1,2,3,4-pentane tetracarboxylic dianhydride, etc. , These can be used alone or in combination of two or more. In addition, it may be used in combination with cyclic aliphatic tetracarboxylic dianhydride and non-cyclic aliphatic tetracarboxylic dianhydride.

Among the tetracarboxylic acid compounds, from the viewpoint of easily improving the light resistance, surface hardness or transparency of the optical film, the above-mentioned alicyclic tetracarboxylic dianhydride or non-condensed polycyclic aromatic tetracarboxylic acid is preferred Dianhydride. As specific examples, 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4' are preferred -Biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl ash tetracarboxylic dianhydride, 2,2 -Bis(3,4-dicarboxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride and mixtures of these, more preferably 3,3', 4,4'-biphenyltetracarboxylic dianhydride and 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride and mixtures of these, further preferably 4,4'-(hexa Fluoroisopropylidene) diphthalic dianhydride.

The dicarboxylic acid compound means a dicarboxylic acid or a dicarboxylic acid derivative, and examples of the dicarboxylic acid derivative include acetyl chloride or ester form of the dicarboxylic acid. The dicarboxylic acid compounds can be used alone or in combination of two or more.

Specific examples of the dicarboxylic acid compound include, for example, 2,5-thiophene dicarboxylic acid, 1,3-cyclobutane dicarboxylic acid, 1,3-cyclopentane dicarboxylic acid, and 1,4-cyclohexane Alkanedicarboxylic acid, 4,4'-oxybisbenzoic acid, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, 3,3'-biphenyl dicarboxylic acid, 2 cyclohexane carboxylic acids or 2 benzoic acids using single bonds, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -or phenylene-linked compounds such as alicyclic dicarboxylic acids or aromatic dicarboxylic acids and their derivatives (eg, acetyl chloride, acid anhydride) ; Aliphatic dicarboxylic acids such as dicarboxylic acid compounds of chain hydrocarbons having a carbon number of 8 or less and their derivatives (such as acetyl chloride, esters), etc. These dicarboxylic acid compounds can be used alone or in combination of two or more. Among these, from the viewpoint of easily obtaining good light resistance of the optical film, 2,5-thiophene dicarboxylic acid or a derivative thereof, particularly 2,5-thiophene dimethyl chloride (sometimes Expressed as TDOC).

In the manufacture of polyimide amide imide resin, the amount of diamine compound, tetracarboxylic acid compound and dicarboxylic acid compound used can be appropriately selected according to the ratio of each structural unit of the desired polyimide amide imide resin .

In the production of polyamidoamide resins, the reaction temperature of the diamine compound, the tetracarboxylic acid compound and the dicarboxylic acid compound is not particularly limited, for example, 20 to 200°C, preferably 25 to 100°C. The reaction time is not particularly limited, for example, it is about 30 minutes to 10 hours. If necessary, the reaction can be carried out under an inert atmosphere or under reduced pressure. In a preferred aspect, the reaction is carried out while stirring under normal pressure and/or inert gas atmosphere. In addition, 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, and examples include water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, and ethylene glycol butyl ether. Alcohol solvents such as 1-methoxy-2-propanol, 2-butoxyethanol, propylene glycol monomethyl ether; 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, 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 ethyl ethane; chlorine-containing solvents such as chloroform and chlorobenzene; amide solvents such as N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF) ; Sulfur-containing solvents such as dimethyl ash, dimethyl sulfoxide, cipros; carbonate-based solvents such as ethylene carbonate and propylene carbonate; and combinations (mixed solvents) of these. Among these, from the viewpoint of solubility, an amide-based solvent can be suitably used.

In the imidization step in the manufacture of polyamidimide resins, the imidization can be carried out in the presence of an imidization catalyst. Examples of the amide imidization catalyst include aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; N-ethylpiperidine, N-propylpiperidine, N -Alicyclic amines (monocyclic) such as butylpyrrolidine, N-butylpiperidine, and N-propylhexahydroaza, etc.; 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-picoline) ), 3-picoline, 4-picoline, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, 2,4-lutidine , 2,4,6-trimethylpyridine, 3,4-cyclopentenopyridine, 5,6,7,8-tetrahydroisoquinoline, and isoquinoline and other aromatic amines. In addition, from the viewpoint of facilitating the amide imidization reaction, it is preferable to use an acid anhydride together with the amide imidization catalyst. Examples of the acid anhydride include conventional acid anhydrides used in the amide imidization reaction, and specific examples thereof include aliphatic acid anhydrides such as acetic anhydride, propionic anhydride, and butyric anhydride, and aromatic acid anhydrides such as phthalic acid.

Polyimide amide imide resin obtained by amide imidization can be separated by conventional methods such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography, etc., or a combination of these separations The method is used for isolation (separation and purification). In a preferred aspect, a large amount of alcohol such as methanol can be added to the reaction solution containing the polyamidoamide resin to precipitate the polyamidoamide resin, and Separate by concentration, filtration, drying, etc.

<Optical Film (A)> The present invention includes an optical film (sometimes referred to as an optical film (A)) containing the polyamidoamide resin of the present invention. Since the optical film containing the polyamidimide resin of the present invention has excellent light resistance, it can effectively suppress the discoloration of the film even when exposed to ultraviolet light. Furthermore, the optical film also has excellent transparency. Therefore, it can be suitably used as a component of an image display device such as a liquid crystal display device or an organic EL display device, especially a front panel (window film) of a flexible display. The front panel has the function of protecting the image display elements in the flexible display. More specifically, examples of image display devices include TVs, smartphones, mobile phones, car navigation systems, tablet PCs (Personal Computers), portable game consoles, electronic paper, indicators, and bulletin boards. , Clocks, and smart watches and other wearable devices. Examples of flexible displays include image display devices with flexible characteristics, such as TVs, smart phones, mobile phones, car navigation systems, tablet PCs, portable game consoles, electronic paper, indicators, and bulletin boards. , Clock, and wearable devices, etc. In one embodiment of the present invention, when the optical film of the present invention is applied to a flexible display device, deterioration such as discoloration caused by ultraviolet rays can be suppressed, and thus the life of the display device can be extended. Therefore, the generation of CO ₂ caused by the discarding of the display device can be suppressed.

Regarding the content of the polyimide amide imine resin in the optical film, from the viewpoint of easily exhibiting good light resistance, it is preferably 40% by mass or more and more preferably 60% with respect to the quality of the optical film. % Or more, further preferably 80% by mass or more, particularly preferably 90% by mass or more, and particularly 95% by mass or more. The upper limit of the content of the polyimide amide imide resin is 100% by mass or less.

The optical film may further contain inorganic materials such as inorganic particles. Examples of the inorganic material include inorganic particles such as titanium oxide particles, aluminum oxide particles, zirconia particles, and silicon dioxide particles, and silicon compounds such as quaternary alkoxysilane such as tetraethyl orthosilicate. From the viewpoint of the stability of the polyimide amide imine varnish used to manufacture the optical film, the inorganic material is preferably inorganic particles, particularly preferably silicon dioxide particles. Inorganic particles can be bonded to each other using molecules with siloxane bonds.

The average primary particle diameter of the inorganic particles is, for example, from 1 to 100 nm, preferably from 5 to 80 nm, and more preferably from 7 to the viewpoint of transparency of the optical film, mechanical properties, and suppression of aggregation of the inorganic particles. 50 nm, particularly preferably 10-30 nm. The average primary particle size can be determined by measuring the 10-point average value of the directional diameter using a transmission electron microscope.

When the optical film contains an inorganic material, regarding the content, the total mass of the optical film is used as a reference, preferably 0.001 to 90% by mass, more preferably 0.01 to 60% by mass, and still more preferably 5 to 40% by mass . If the content rate of the inorganic material is within the above range, it tends to be easy to achieve both transparency and mechanical properties of the optical film.

The optical film may further contain an ultraviolet absorber. The ultraviolet absorber can be appropriately selected from those generally used as ultraviolet absorbers in the field of resin materials. Ultraviolet absorbers may contain compounds that absorb light at wavelengths below 400 nm. Examples of the ultraviolet absorber include at least one compound selected from the group consisting of benzophenone compounds, salicylate-based compounds, benzotriazole-based compounds, and tri-based compounds. The ultraviolet absorber may be used alone or in combination of two or more. In this specification, the term "system compound" refers to a derivative of the compound to which the "system compound" is attached. For example, the so-called "benzophenone compound" refers to a compound having a benzophenone as a parent skeleton and a substituent bonded to benzophenone.

Generally, by containing an ultraviolet absorber in the optical film, the deterioration of the polyamidoamide resin is suppressed. On the other hand, as described above, the optical film containing the polyamidoamide resin of the present invention may contain an ultraviolet absorber, but even without an ultraviolet absorber, it can exhibit excellent light resistance. Therefore, the content of the ultraviolet absorber may be preferably less than 1 part by mass, more preferably 0.5 part by mass or less, and further preferably 0.1 part by mass or less with respect to 100 parts by mass of the optical film.

The optical film may further contain additives other than inorganic materials and ultraviolet absorbers. Examples of other additives include antioxidants, mold release agents, stabilizers, blueing agents, flame retardants, pH adjusters, silica dispersants, lubricants, thickeners, and leveling agents. When other additives are contained, the content thereof is preferably 0.005 to 20% by mass, more preferably 0.01 to 15% by mass, more preferably about 0.1 to 10% by mass relative to the mass of the optical film.

The thickness of the optical film can be appropriately selected according to the application, preferably 25 μm or more, more preferably 30 μm or more, and preferably 100 μm or less, more preferably 80 μm or less, and further preferably 60 μm or less, which can be Any combination of these upper and lower limits. The thickness of the optical film can be measured using a micrometer, for example.

The yellowness of the optical film is preferably 8 or less, more preferably 5 or less, and further preferably 3 or less, particularly preferably 2 or less, and particularly preferably 1 or less. If the yellowness of the optical film is equal to or lower than the above upper limit, the transparency becomes good. For example, when it is used in a front panel of an image display device, it can contribute to higher visibility. The yellowness is usually -5 or more, preferably -2 or more. In addition, the yellowness (YI value) can be measured using a UV-visible-near-infrared spectrophotometer for light transmission from 300 to 800 nm, and 3 stimulus values (X, Y, Z) can be obtained and based on YI=100 Calculated by the formula of ×(1.2769X－1.0592Z)/Y.

The amount of change in yellowness (ΔYI) before and after the light resistance test of the optical film is preferably 2.5 or less, more preferably 2.0 or less, even more preferably 1.5 or less, and particularly preferably 1.0 or less. The light resistance test is a test in which the film is continuously irradiated with ultraviolet rays for 24 hours, and the measurement of YI can be measured in the same manner as the above-mentioned yellowness measurement method. ΔYI can be measured by the method described in the Examples, for example.

In the optical film, the total light transmittance at a thickness of 50 μm is preferably 80% or more, more preferably 85% or more, and still more preferably 90% or more. If the total light transmittance is above the lower limit, the transparency becomes good. For example, when it is used in the case of the front panel of an image display device, it can contribute to higher visibility. In addition, the upper limit of the total light transmittance is usually 100% or less. The total light transmittance can be measured using a haze meter in accordance with JIS K 7105:1981, for example, by the method described in the examples.

The haze of the optical film is preferably 3.0% or less, more preferably 2.0% or less, and further preferably 1.0% or less. If the haze of the optical film is equal to or less than the above upper limit, the transparency becomes good. For example, when it is used in a front panel of an image display device, it can contribute to higher visibility. In addition, the lower limit of haze is usually 0.01% or more. In addition, the haze can be measured using a haze meter, for example.

<Manufacturing method of optical film (A)> The optical film containing the polyimide amide imine resin of the present invention is not particularly limited, and can be produced by a method including the following steps, for example: (a) Steps (preparation step of varnish) of preparing a solution containing the above-mentioned polyimide-imide resin (in the case where it is called polyamidimide-imide varnish), (b) a step of applying a polyimide amide imine varnish to a substrate to form a coating film (coating step), and (c) The step of drying the applied solution (coating film) to form an optical film (film forming step).

In the step of preparing the varnish, the polyamidoamide resin is dissolved in the solvent, and if necessary, the above additives and the like are added and stirred and mixed to prepare the polyamidoamide resin varnish.

The solvent used in the preparation of the varnish is not particularly limited as long as it can dissolve the polyamidoamide resin. As the solvent, for example, the solvent exemplified in the item of <Production Method of Polyamide Amide Imide Resin> can be cited. Among these solvents, an amide-based solvent or a lactone-based solvent can be suitably used. These solvents can be used alone or in combination of two or more. The solid content concentration of the polyamidoamide imine varnish is preferably 1 to 25% by mass, more preferably 5 to 15% by mass.

In the coating step, a polyimide amide imide varnish is applied to the substrate by a known coating method to form a coating film. Examples of well-known coating methods include roll coating methods such as wire bar coating method, reverse coating method, and gravure coating method, die nozzle coating method, kama coating method, and die lip coating method. Spin coating method, screen coating method, spray coating method, dipping method, spray method, casting method, etc.

In the film forming step, the optical film can be formed by drying the coating film and peeling it from the substrate. After peeling, a step of drying the optical film may be further provided. The drying of the coating film can usually be carried out at a temperature of 50 to 350°C. If necessary, the primer film can be dried in an inert atmosphere or under reduced pressure.

Examples of the substrate include metal tapes such as SUS, PET (Polyethylene Terephthalate) film, PEN (Polyethylene Naphthalate) film, and polyimide Resin films such as films, polyimide films, and other polyamidimide films. Among them, from the viewpoint of excellent heat resistance, PET films, PEN films, and the like are preferable, and further, from the viewpoints of adhesiveness, easy peelability, and cost during film formation with optical films, PET films are more preferable.

[式(1)及式(2b)中，X及L分別獨立地表示二價有機基，Y表示四價有機基]，且 包含波長420 nm下之透光率為70%以上，波長375 nm下之透光率為5%以下之光學膜(有時稱為光學膜(B))。本發明之光學膜由於波長420 nm下之透過率為80%以上，波長375 nm下之透過率為5%以下，故而可有效地吸收紫外光，可表現出優異之耐光性。<Optical film (B)> The present invention includes a polyamidoamide resin containing structural units represented by formula (1) and formula (2b):

[In formula (1) and formula (2b), X and L independently represent a divalent organic group, and Y represents a tetravalent organic group], and include a light transmittance of 70% or more at a wavelength of 420 nm and a wavelength of 375 nm An optical film with a light transmittance of 5% or less (sometimes referred to as an optical film (B)). Since the optical film of the present invention has a transmittance of 80% or more at a wavelength of 420 nm and a transmittance of 5% or less at a wavelength of 375 nm, it can effectively absorb ultraviolet light and can exhibit excellent light resistance.

From the viewpoint of easily improving the light resistance of the optical film, the light transmittance at a wavelength of 420 nm is preferably 80% or more, more preferably 85% or more, and the light transmittance at a wavelength of 375 nm is preferably 3% or less, More preferably, it is below 1%. In addition, the light transmittance can be measured using an ultraviolet-visible-near infrared spectrophotometer, for example, it can be measured by the method described in the examples.

The structural unit represented by the formula (1) constituting the polyamidoimide resin is the same as the structural unit represented by the formula (1) described in the above item <polyamide amide imine resin>.

In formula (2b), L is independently represented by L1 or L2. L1 is the same as Z in formula (2), and L2 is a divalent organic group other than Z. L2 is preferably an organic group having a carbon number of 4 to 40 which may be substituted by a hydrocarbon group having a carbon number of 1 to 8, an alkoxy group having a carbon number of 1 to 6, or a hydrocarbon group having a carbon number of 1 to 8 substituted by fluorine, and more preferably A divalent organic group having 4 to 40 carbon atoms and having a cyclic structure which may be substituted with a hydrocarbon group having 1 to 8 carbon atoms or a hydrocarbon group having 1 to 8 carbon atoms substituted with fluorine. Examples of the cyclic structure include alicyclic or aromatic rings. Examples of the organic group of L2 include formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), and formula ( 28) Among the bonding bonds of the groups represented by formula (29), two non-adjacent groups are substituted with hydrogen atoms, and a divalent chain hydrocarbon group having a carbon number of 6 or less. Among these, if L1 (bivalent heterocyclic ring) is used as L, it is easy to adjust the transmittance at a wavelength of 420 nm to 80% or more, and to adjust the transmittance at a wavelength of 375 nm to 5% or less. Furthermore, the preferred divalent heterocycle corresponding to L1 is also the same as the one related to Z described in the item <Polyamidoamide resin>, that is, as L1, it is preferable to contain sulfur The divalent heterocyclic ring of the atom is more preferably a divalent heterocyclic ring represented by formula (a). In one embodiment of the present invention, the polyamidoamide resin may include a plurality of types of L, and the plurality of types of L may be the same or different from each other.

In the optical film of the present invention, in order to adjust the transmittance at a wavelength of 420 nm to 70% or more, and to adjust the transmittance at a wavelength of 375 nm to 5% or less, an absorbance contained at a wavelength of 370 to 400 nm may be used. The method of ultraviolet absorber. However, the optical film of the present invention uses a polyimide amide imide resin containing the structural unit represented by formula (2), even if it does not contain an ultraviolet absorber, it can also exhibit excellent light resistance, so the ultraviolet absorber can be used The content is preferably less than 1 part by mass relative to 100 parts by mass of the optical film, more preferably 0.5 parts by mass or less, still more preferably 0.1 parts by mass or less, and particularly preferably 0 parts by mass. As an ultraviolet absorber, the ultraviolet absorber described in the item of <optical film (A)> can be mentioned. Furthermore, since the optical film of the present invention is also excellent in heat resistance, even when exposed to a high-temperature environment, it can maintain excellent light resistance, and can effectively suppress discoloration of the film.

In addition to the ultraviolet absorber, the optical film of the present invention may further contain inorganic materials, other additives, and the like. Examples of the inorganic material or other additives include the inorganic materials or other additives described in the section of <optical film (A)>. The content of the inorganic material or other additives may also be the content described in the item of <optical film (A)>.

The production of the polyimide amide imine resin or the production of the optical film can be performed by referring to the above-mentioned <Manufacturing of Polyamide Amide Imide Resin> and the above-mentioned <Manufacturing Method of Optical Film (A)>.

<Laminate> The optical film of the present invention may be a single layer or a laminate. The optical film of the present invention may be used directly, or it may be further used as a laminate with other films or layers. In the present invention, when the optical film is a laminate, all layers including one layer or both layers laminated on the optical film are referred to as an optical film. In addition, for convenience of description, the optical film in the form of a laminate is sometimes called a laminate.

When the optical film of the present invention is a laminate, it may have at least one functional layer on at least one side of the optical film. Examples of the functional layer include an ultraviolet absorbing layer, a hard coat layer, an undercoat layer, a gas barrier layer, an adhesive layer, a hue adjustment layer, and a refractive index adjustment layer. The functional layer can be used alone or in combination of two or more.

The optical film of the present invention can be a laminate with a protective film as shown below. That is, the optical film of the present invention may include a protective film on at least one side. In the case where the optical film has a functional layer on one side or both sides, a protective film may be provided on the surface of the functional layer.

The protective film is attached to the unsupported surface of the optical film. When the winding is in the form of a laminate, when there is a problem with the rollability such as adhesion, the above can be added, and a protective film can be attached to the surface of the support opposite to the optical film. The protective film attached to the optical film is a film for temporarily protecting the surface of the optical film, and is not particularly limited as long as it is a peelable film that can protect the surface of the optical film. For example, polyester resin films such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyolefin resin films such as polyethylene and polypropylene films; acrylic The resin film or the like is preferably selected from the group consisting of polyolefin resin film, polyethylene terephthalate resin film and acrylic resin film. In the case where the protective film is included on both sides of the laminate (optical film), the protective films on each side may be the same as or different from each other.

The thickness of the protective film is not particularly limited, but is usually 10 to 100 μm, preferably 10 to 80 μm, and more preferably 10 to 50 μm. When the protective film is included on both sides of the laminate (optical film), the thickness of the protective film on each side may be the same or different.

(Laminate film roll) In this specification, the layered product (for example, a support, an optical film, and an optional protective film) wound around the core in a roll is called a layered film roll. In the continuous production of laminate film rolls, due to space and other constraints, in most cases it is temporarily stored in the form of a film roll, and the laminate film roll is also one. In the form of a laminate film roll, since the laminate is extremely strongly wound, the substance causing the cloudiness on the support is easily transferred to the optical film. However, if the support having a specific contact angle to water of the present invention is used, the white turbid substance derived from the support is not easily transferred to the optical film, and even if it is wound tightly in the laminate film roll, white turbidity is not easily generated.

Examples of the material constituting the core of the laminate film roll include polyethylene resin, polypropylene resin, polyvinyl chloride resin, polyester resin, epoxy resin, phenol resin, melamine resin, silicone resin, and polyurethane. Synthetic resins such as ester resins, polycarbonate resins, ABS (Acrylonitrile-Butadiene-Styrene, Acrylonitrile-Butadiene-Styrene) resins; metals such as aluminum; fiber-reinforced plastics (FRP: the plastic contains glass fibers and other fibers And composite materials to improve strength) and so on. The winding core is formed into a cylindrical shape or a cylindrical shape, and the diameter thereof is, for example, 80 to 170 mm. In addition, the diameter of the film roll (diameter after winding) is not particularly limited, but is usually 200 to 800 mm.

<Flexible display device> The present invention includes a flexible display device provided with the above optical film. The flexible display device (optical laminate) may further include a layer selected from the group consisting of a polarizing plate and a touch sensor on one side of the optical film. That is, the flexible display device of the present invention may further include a touch sensor and/or a polarizing plate. As described above, in the flexible display device, the optical film of the present invention is used as a front panel (window film). Therefore, the optical film of the present invention is sometimes referred to as a window film. The window film may be provided with a window hard coating. In addition, the above window film may be provided with a polarizing plate or a touch sensor through an adhesive layer if necessary.

On at least one side of the window film or the polarizing plate, a colored light-shielding pattern printed around the frame may be provided, and the light-shielding pattern may be in the form of a single layer or multiple layers. Moreover, the polarizing plate may be directly or directly bonded to one surface of the window film. For example, the polarizing plate may be continuously extended to the non-display area or the frame portion, and may be a general polarizing plate including a protective film attached to at least one surface of the polyvinyl alcohol-based polarizing element and the polyvinyl alcohol-based polarizing element.

As an aspect of the present invention, in a structure in which a polarizer and a touch sensor on one surface of the window film are integrated, the order of arrangement of the polarizer and the touch sensor is not limited, and can be determined according to the window film and the polarized light The order of the board, the touch sensor and the display panel can also be arranged in the order of the window film, the touch sensor, the polarizing plate and the display panel. When the window film, the polarizing plate, the touch sensor and the display panel are arranged in this order, the touch sensor exists under the polarizing plate when viewing the image display device from the self-recognition side, so it is not easy to recognize To the advantages of the touch sensor pattern. In this case, the substrate of the touch sensor preferably has a front phase difference of ±2.5 nm or less. As such a material, as the non-stretched film, for example, it may be one selected from the group consisting of materials such as triethyl cellulose, triethyl cellulose, cycloolefin, cycloolefin copolymer, polynorcamene copolymer, etc. Films of more than one material. On the other hand, it may have a structure without a touch sensor substrate and only the pattern is transferred to the window film and the polarizing plate.

The polarizing plate and the touch sensor can be disposed between the window film and the display panel by using a transparent adhesive layer or a transparent adhesive layer, and is more preferably a transparent adhesive layer. In the case of a window film, a polarizing plate, a touch sensor, and a display panel, the transparent adhesive layer may be located between the window film and the polarizing plate, and between the touch sensor and the display panel. When arranged in the order of window film, touch sensor, polarizing plate and display panel, the transparent adhesive layer can be located between the window film and the touch sensor, and between the touch sensor and the polarizing plate 1. Between the polarizer and the display panel.

The thickness of the transparent adhesive layer is not particularly limited, and may be, for example, 1 to 100 μm. In the transparent adhesive layer of the present invention, the thickness of the lower adhesive layer is preferably more than the thickness of the upper adhesive layer, and the viscoelasticity at -20 to 80°C is 0.2 MPa or less. In this case, the noise generated by the interference between the touch sensor and the display panel can be reduced, the interface stress during bending can be relaxed, and the destruction of the upper and lower substrates can be suppressed. In terms of suppressing the cohesive failure of the adhesive and alleviating the interfacial stress, it is more preferable that the above-mentioned viscoelasticity may be 0.01 to 0.15 MPa.

(Polarizer) The polarizing plate laminated on the window film may be a polarizing element alone or comprising a polarizing element and a protective film attached to at least one side thereof. The thickness of the polarizing plate is not particularly limited, and may be 100 μm or less, for example. If the thickness is 100 μm or less, the flexibility is not easily reduced. Within the above range, it may be, for example, 5 to 100 μm.

The above-mentioned polarizing element may be a film-type polarizing element generally used in this field, which is manufactured by including steps of swelling, dyeing, cross-linking, stretching, washing with water, and drying the polyvinyl alcohol-based film, and as another example, The composition for liquid crystal coating can be coated to form a polarized coating layer. The composition for liquid crystal coating is a coating layer forming composition, and may contain a polymerizable liquid crystal compound and a dichroic dye. The above-mentioned polarizing coating layer can be produced, for example, by applying an alignment film-forming composition to a substrate, imparting alignment to form an alignment film, and coating the alignment film with a liquid crystal compound and a dichroic dye The coating layer forming composition forms a liquid crystal coating layer. Such a polarizing coating layer is formed to have a thinner thickness than a polarizing plate containing a protective film attached to the both sides of the polyvinyl alcohol-based polarizing element with an adhesive. The thickness of the polarizing coating layer may be generally 0.5 to 10 μm, preferably 2 to 4 μm.

(Alignment film forming composition) The above-mentioned alignment film-forming composition may include an alignment agent, a photopolymerization initiator, and a solvent generally used in this field. As the above-mentioned alignment agent, alignment agents generally used in this field can be used without particular limitation. For example, a polyacrylate polymer, a polyamic acid, a polyimide polymer, or a polymer containing a cinnamate group can be used as an alignment agent. When photoalignment is applied, it is preferable to use a compound containing cinnamic acid Ester based polymer.

Examples of the application of the alignment film-forming composition include spin coating, extrusion molding, dip coating, flow coating, spray coating, roll coating, gravure coating, and micro gravure coating. Preferably, an in-line coating method is used. The above-mentioned alignment film-forming composition is subjected to an alignment treatment after being coated and optionally dried. The above-mentioned alignment treatment can employ various methods well-known in the art without limitation, and it is preferable that a photo-alignment film can be used. The photo-alignment film can generally be applied to a substrate by applying a photo-alignment film forming composition containing a polymer or monomer having a photoreactive group and a solvent, and irradiating polarized light (preferably polarized UV (Ultra Violet, ultraviolet ray) )). The optical alignment film is further preferred in that the direction of the alignment limiting force can be arbitrarily controlled by selecting the polarization direction of the polarized light to be irradiated.

The thickness of the optical alignment film is usually 10 to 10,000 nm, preferably 10 to 1,000 nm, and more preferably 10 to 500 nm. If the thickness of the optical alignment film is within the above range, the alignment restricting force is sufficiently exhibited.

(Polarized coating layer forming composition) The polarizing coating layer may be formed by coating the polarizing coating layer forming composition. Specifically, the polarizing coating layer forming composition is a composition that contains one or more polymerizable liquid crystals (hereinafter, sometimes referred to as polymerizable liquid crystals (B)) as host compounds in addition to dichroic dyes (Hereinafter, there is a case called composition B).

The so-called "dichroic pigment" refers to a pigment having a property in which the absorbance in the long axis direction of the molecule is different from the absorbance in the short axis direction. The dichroic pigment is not limited as long as it has such properties, and it may be a dye or a pigment. It can be used in combination with two or more kinds of dyes, can be used in combination with two or more kinds of pigments, and can also be used in combination with dyes and pigments.

The dichroic pigment preferably has a maximum absorption wavelength (λ _MAX ) in the range of 300 to 700 nm. Examples of such dichroic pigments include acridine pigments, cyanine pigments, cyanine pigments, naphthalene pigments, azo pigments and anthraquinone pigments, of which azo pigments are preferred. Examples of azo pigments include monoazo pigments, disazo pigments, triazo pigments, tetraazo pigments and stilbene pigments, preferably disazo pigments and triazo pigments.

The liquid crystal state displayed by the polymerizable liquid crystal (B) is preferably a smectic phase, and in terms of producing a polarizing layer with a higher degree of alignment, it is more preferably a higher-order smectic phase. The polymerizable liquid crystal (B) showing the smectic phase is called a polymerizable smectic liquid crystal compound. The polymerizable liquid crystal (B) can be used alone or in combination. In addition, when two or more types of polymerizable liquid crystals are combined, at least one type is preferably a polymerizable liquid crystal (B), and more preferably two or more types are a polymerizable liquid crystal (B). By combination, there are cases where the liquid crystallinity can be temporarily maintained even at a temperature below the liquid crystal-crystal phase transition temperature. The polymerizable liquid crystal (B) is manufactured by a well-known method described in Lub et al. Recl. Trav. Chim. Pays-Bas, 115, 321-328 (1996), or Japanese Patent No. 4719156, for example. The content of the dichroic pigment in the composition B can be appropriately adjusted according to the type of the dichroic pigment, etc., and is preferably 0.1 part by mass or more and 50 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal (B). Below, it is more preferably 0.1 mass part or more and 20 mass parts or less, and further preferably 0.1 mass part or more and 10 mass parts or less. If the content of the dichroic pigment is within the above range, the alignment of the polymerizable liquid crystal (B) can be polymerized without disrupting the alignment, and the tendency to hinder the alignment of the polymerizable liquid crystal (B) is small.

Composition B preferably contains a solvent. Generally, a smectic liquid crystal compound has a high viscosity, so a composition containing a solvent is easy to apply, and as a result, a polarizing film is easily formed in many cases. The solvent may be the same as the solvent contained in the above-mentioned alignment polymer composition, and can be appropriately selected according to the solubility of the polymerizable liquid crystal (B) and the dichroic dye. The content of the solvent is preferably 50 to 98% by mass relative to the total amount of composition B. In other words, the solid content component in Composition B is preferably 2 to 50% by mass.

Composition B preferably contains one or more leveling agents. The leveling agent has a function of adjusting the fluidity of the composition B and making the coating film obtained by coating the composition B flatter. Specifically, a surfactant may be mentioned. When the composition B contains a leveling agent, its content is preferably 0.05 parts by mass or more and 0.05 parts by mass or less, and more preferably 0.05 parts by mass or more and 3 parts by mass or less relative to 100 parts by mass of the polymerizable liquid crystal. . If the content of the leveling agent is within the above range, it is easy to align the polymerizable liquid crystal horizontally, and there is a tendency that the obtained polarizing layer becomes smoother. If the content of the leveling agent with respect to the polymerizable liquid crystal is within the above range, there is a tendency that unevenness is less likely to occur in the obtained polarizing layer.

Composition B preferably contains one or more polymerization initiators. The polymerization initiator is a compound that can start the polymerization reaction of the polymerizable liquid crystal (B), and it is preferably a photopolymerization initiator in terms of starting the polymerization reaction at a lower temperature. Specifically, photopolymerization initiators that can generate active radicals or acids by the action of light can be cited. Among them, photopolymerization initiators that generate free radicals by the action of light are preferred. Examples of the polymerization initiator include benzoin compounds, benzophenone compounds, alkyl benzophenone compounds, acyl phosphine oxide compounds, triammonium compounds, iodonium salts, and manganese salts.

When the composition B contains a polymerization initiator, its content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal contained in the composition, and is preferably 100 parts by mass of the polymerizable liquid crystal It is 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 0.5 to 8 parts by mass. If the content of the polymerization initiator is within this range, the polymerizable liquid crystal (B) can be polymerized without disturbing the alignment. When the composition B contains a photopolymerization initiator, the above composition may further contain a photo-increasing or decreasing agent. When the composition B contains a photopolymerization initiator and a photoincrease/decrease agent, the polymerization reaction of the polymerizable liquid crystal contained in the composition can be further suppressed. The use amount of the light increasing and decreasing agent can be appropriately adjusted according to the types and amounts of the photopolymerization initiator and the polymerizable liquid crystal, and it is preferably 0.1 to 30 parts by mass relative to 100 parts by mass of the polymerizable liquid crystal. It is preferably 0.5 to 10 parts by mass, and more preferably 0.5 to 8 parts by mass.

In order to more stably perform the polymerization reaction of the polymerizable liquid crystal , the composition B may contain an appropriate amount of a polymerization inhibitor, whereby it is easy to control the degree of polymerization reaction of the polymerizable liquid crystal. When the composition B contains a polymerization inhibitor, its content can be appropriately adjusted according to the type and amount of the polymerizable liquid crystal, and the amount of the light-increasing and reducing agent used, relative to 100 parts by mass of the polymerizable liquid crystal It is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 10 parts by mass, and still more preferably 0.5 to 8 parts by mass. If the content of the polymerization inhibitor is within this range, the polymerizable liquid crystal can be polymerized without disturbing the alignment.

(Method of making polarized coating layer) The polarizing coating layer is generally formed by applying the polarizing coating layer-forming composition on the substrate subjected to the alignment treatment, and polymerizing the polymerizable liquid crystal in the obtained coating film. The method of applying the polarizing coating layer forming composition is not limited. As the alignment processing, those exemplified above can be cited. By applying the polarizing coating layer forming composition, the solvent is dried and removed under the condition that the polymerizable liquid crystal contained in the obtained coating film is not polymerized, and a dry coating film is formed. Examples of the drying method include a natural drying method, an air drying method, a heating drying method, and a reduced pressure drying method. When the polymerizable liquid crystal is a polymerizable smectic liquid crystal compound, it is preferable to change the liquid crystal state of the polymerizable smectic liquid crystal compound contained in the dry film to a nematic phase (nematic liquid crystal state) , Transferred to smectic phase. In order to form a smectic phase through the nematic phase, for example, the following method is used: heating the dried coating film at a temperature above the temperature at which the polymerizable smectic liquid crystal compound contained in the dried coating phase transitions to the liquid crystal state of the nematic phase, Then, it is cooled to a temperature at which the polymerizable smectic liquid crystal compound shows the liquid crystal state of the smectic phase. Next, a method of photopolymerizing the polymerizable liquid crystal while maintaining the liquid crystal state of the smectic phase after the liquid crystal state of the polymerizable liquid crystal in the dry film is a smectic phase will be described. In photopolymerization, the light irradiated to the dry film can be based on the type of photopolymerization initiator contained in the dry film and the type of polymerizable liquid crystal (especially the type of photopolymerizable group possessed by the polymerizable liquid crystal) The amount is appropriately selected according to the amount. As specific examples thereof, active energy rays selected from the group consisting of visible light, ultraviolet light, and laser light can be cited. Among these, in terms of easily controlling the progress of the polymerization reaction or being applicable to a wide range of users in the field as photopolymerization devices, ultraviolet light is preferred. By performing photopolymerization, the polymerizable liquid crystal is polymerized while maintaining the liquid crystal state of a smectic phase, preferably a higher-order smectic phase, to form a polarizing layer.

(Phase difference coating layer) In one embodiment of the present invention, the polarizing plate may include a phase difference coating layer. According to optical characteristics, the phase difference coating layer is collectively referred to as a λ/2 layer, a λ/4 layer, a positive C layer, and the like. The phase difference coating layer can be formed, for example, by applying a coating layer forming composition containing a liquid crystal compound to a substrate film that has been subjected to alignment treatment to form a liquid crystal coating layer, and then applying the liquid crystal coating layer The base film is peeled off after the adhesive layer is attached to the polarizing plate, but it is not limited to this method. As the base film, a polymer film exemplified as the protective film may be used, or the base material surface on the side where the alignment film and the retardation layer are formed may be surface-treated before forming the alignment film. The above-mentioned alignment film-forming composition, its coating and drying method, etc. are the same as those described in the polarizing coating layer, so description is omitted in order to avoid repetition. The composition of the coating layer forming composition is the same as that described in the polarizing coating layer except that the dichroic dye is not included. In addition, the coating, drying, and curing methods of the coating layer-forming composition are the same as those described in the polarizing coating layer, so description is omitted to avoid repetition.

The thickness of the phase difference coating layer may be generally 0.5 to 10 μm, preferably 1 to 4 μm.

In one embodiment of the present invention, the optical characteristics can be adjusted by the thickness of the coating layer, the alignment state of the polymerizable liquid crystal compound, and the like. Specifically, by adjusting the thickness of the phase difference coating layer, a phase difference coating layer that imparts a desired in-plane phase difference can be produced. The in-plane phase difference value (in-plane retardation value, Re) is a value defined by equation (1). In order to obtain the required Re, Δn and film thickness (d) can be adjusted. Re=d×Δn(λ) Formula (1) (here, Δn=nx-ny) (In equation (1), Re represents the in-plane retardation value, d represents the thickness of the retardation coating layer, and Δn represents the birefringence. Considering the case of the refractive index ellipsoid formed by the alignment of the polymerizable liquid crystal compound , The refractive index in three directions, that is, nx, ny, and nz are defined as follows. nx represents the principal refractive index parallel to the direction of the substrate plane in the refractive index ellipsoid forming the phase difference layer. ny is parallel to the phase difference The substrate plane in the refractive index ellipsoid of the layer represents the refractive index in a direction orthogonal to the direction of nx. nz represents the refractive index perpendicular to the direction of the substrate plane in the refractive index ellipsoid forming the retardation layer. When the retardation layer is a λ/4 layer, the in-plane retardation value Re(550) is usually in the range of 113 to 163 nm, preferably in the range of 130 to 150 nm. When the retardation layer is a λ/2 layer In this case, Re(550) is in the range of 250-300 nm, preferably in the range of 250-300 nm)

In addition, according to the alignment state of the polymerizable liquid crystal compound, a phase difference layer showing a phase difference in the thickness direction can be produced. The phase difference in the thickness direction shows the characteristic that the phase difference value Rth in the thickness direction becomes negative in equation (2). Rth＝[(nx＋ny)/2－nz]×d Formula (2) (In equation (2), nx, ny, nz, and d are the same as defined above) The in-plane phase difference value Re(550) of the positive C layer is usually in the range of 0 to 10 nm, preferably in the range of 0 to 5 nm, and the phase difference value Rth in the thickness direction is usually in the range of -10 to -300 nm. It is preferably in the range of -20 to -200 nm. The polarizing plate of the present invention may have two or more retardation coating layers. In the case of having two retardation coating layers, the first retardation coating layer is used to make a circularly polarized λ/4 layer. 2 The phase difference coating layer may be a positive C layer for improving the color tone observed from the oblique direction. In addition, the first retardation coating layer is a positive C layer for improving the color tone observed from an oblique direction, and the second retardation coating layer may be a λ/4 layer for producing circularly polarized light.

( Adhesive or Adhesive ) In one embodiment of the present invention, the polarizing coating layer and the first retardation coating layer, or the first retardation coating layer and the second retardation coating layer can be passed through an adhesive or Then the agent is attached. As the adhesive for forming the adhesive layer, an aqueous adhesive, an active energy ray-curable adhesive, or a thermosetting adhesive can be used, and preferably an aqueous adhesive, an active energy ray-curable adhesive. As the adhesive layer, the following can be used.

Examples of the water-based adhesive include an adhesive containing a polyvinyl alcohol-based resin aqueous solution, an aqueous two-component urethane-based latex adhesive, and the like. Among them, an aqueous adhesive containing a polyvinyl alcohol-based resin aqueous solution can be suitably used. As the polyvinyl alcohol-based resin, in addition to the vinyl alcohol homopolymer obtained by saponifying polyvinyl acetate as a homopolymer of vinyl acetate, vinyl acetate and other monomers copolymerizable therewith can be used A polyvinyl alcohol copolymer obtained by saponification of the copolymer, or a modified polyvinyl alcohol polymer obtained by partially modifying the hydroxyl groups, etc. The water-based adhesive may include a crosslinking agent such as an aldehyde compound (such as glyoxal), an epoxy compound, a melamine-based compound, a methylol compound, an isocyanate compound, an amine compound, and a polyvalent metal salt.

In the case of using an aqueous adhesive, it is preferable to perform a drying step for removing water contained in the aqueous adhesive after the coating layer is attached.

The so-called active energy ray-curable adhesive is an adhesive containing a curable compound that is cured by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays, and is preferably an ultraviolet-curable adhesive.

The curable compound may be a cationically polymerizable curable compound or a radically polymerizable curable compound. Examples of the cationic polymerizable hardenable compound include epoxy compounds (compounds having one or more epoxy groups in the molecule), or oxetane compounds (having one or more in the molecule). 2 or more oxetane rings), or a combination of these. Examples of the radically polymerizable curable compound include (meth)acrylic compounds (compounds having one or more (meth)acryloyloxy groups in the molecule) or radically polymerizable Other vinyl systems of double bonds, or a combination of these. A cationically polymerizable hardening compound and a radically polymerizable hardening compound can be used together. The active energy ray-curable adhesive generally further includes a cationic polymerization initiator and/or a radical polymerization initiator for starting the hardening reaction of the above-mentioned curable compound.

When bonding the coating layer, in order to improve adhesion, at least any bonding surface of the bonding surface may be subjected to surface activation treatment. Examples of surface activation treatment include corona treatment, plasma treatment, discharge treatment (glow discharge treatment, etc.), flame treatment, ozone treatment, UV ozone treatment, ionizing active ray treatment (ultraviolet treatment, electron beam treatment, etc.) Dry treatment; Wet treatment such as ultrasonic treatment, saponification treatment, tackifying coating treatment using solvents such as water or acetone. These surface activation treatments can be performed alone or in combination of two or more.

The thickness of the adhesive layer can be adjusted according to its adhesive force, preferably 0.1 to 10 μm, and more preferably 1 to 5 μm. In an embodiment of the present invention, when a plurality of the above-mentioned adhesive layers are used, they can be manufactured using the same material or different materials, and can have the same thickness or different thicknesses.

The adhesive layer may contain resins such as (meth)acrylic resins, rubber resins, polyurethane resins, polyester resins, polysiloxane resins, and polyvinyl ether resins as main components. Adhesive composition. Among them, an adhesive composition using a polyester-based resin or (meth)acrylic-based resin excellent in transparency, weather resistance, heat resistance, etc. as a base polymer is more suitable. The adhesive composition may be active energy ray hardening type or thermosetting type. As the adhesive resin used in the present invention, those having a weight average molecular weight in the range of 300,000 to 4,00,000 can be generally used. In consideration of durability, especially heat resistance, the weight average molecular weight is preferably 500,000 to 3,000,00, and more preferably 650,000 to 2,000,000. If the weight-average molecular weight is greater than 300,000, it is preferable in terms of heat resistance, and if the weight-average molecular weight is less than 4,000,000, it is also preferable in terms of adhesion and adhesion reduction. In addition, the weight average molecular weight refers to the value calculated by GPC (gel permeation chromatography) and converted by polystyrene.

Furthermore, a crosslinking agent may be contained in the adhesive composition. As the crosslinking agent, an organic crosslinking agent or a multifunctional metal chelate compound can be used. Examples of the organic-based crosslinking agent include isocyanate-based crosslinking agents, peroxide-based crosslinking agents, epoxy-based crosslinking agents, and imine-based crosslinking agents. Multifunctional metal chelates are those in which multivalent metals and organic compounds are covalently bonded or coordinated. Examples of polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti Wait. Examples of the atom in the organic compound that performs covalent bonding or coordinate bonding include an oxygen atom and the like. Examples of the organic compound include an alkyl ester, alcohol compound, carboxylic acid compound, ether compound, and ketone compound.

When a crosslinking agent is contained, the amount used is preferably 0.01 to 20 parts by mass, and more preferably 0.03 to 10 parts by mass relative to 100 parts by mass of the binder resin. Furthermore, if the cross-linking agent exceeds 0.01 parts by mass, the cohesive force of the adhesive layer tends not to be insufficient, and there is little risk of foaming when heated, on the other hand, if it is less than 20 parts by mass, the moisture resistance Relatively sufficient, peeling is unlikely to occur in reliability tests and the like.

As an additive, a silane coupling agent is preferably blended. Examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethane. Silicon compounds with epoxy structure such as trimethoxysilane; 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-( 2-aminoethyl)-3-aminopropylmethyldimethoxysilane and other silicon compounds containing amine groups; 3-chloropropyltrimethoxysilane; trimethoxysilane containing acetoacetyl groups , 3-propenyl propyl propyl trimethoxy silane, 3-methacryl propyl propyl triethoxy silane and other (meth) acrylic group-containing silane coupling agent; 3-isocyanate propyl triethoxy Silane coupling agent containing isocyanate group, etc. Silane coupling agent can provide durability, especially the effect of suppressing peeling under humidified environment. The amount of the silane coupling agent used is preferably 1 part by mass or less relative to 100 parts by mass of the adhesive resin, more preferably 0.01 to 1 part by mass, and still more preferably 0.02 to 0.6 part by mass.

Furthermore, the adhesive composition may contain other well-known additives. For example, powders such as colorants and pigments, dyes, surfactants, plasticizers, and adhesion-imparting agents may be appropriately added to the adhesive composition according to the intended use. , Surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particles, foils, etc. In addition, a redox system added with a reducing agent can be used within a controllable range.

The thickness of the adhesive layer is not particularly limited. For example, it is about 1 to 100 μm, preferably 2 to 50 μm, and more preferably 3 to 30 μm. By thinning the thickness of the adhesive layer, the total amount of acid in the adhesive layer is reduced. As a result, the acid component is less likely to corrode the wiring of the substrate. In addition, the adhesive layer included in the second layer can be adjusted according to the thickness of the flexible printed circuit board to be fitted.

(The protective layer) In one embodiment of the present invention, the polarizing plate may be in a form having at least one protective layer, may be located on one side of the polarizing element forming the polarizing plate, or may be located in phase when the polarizing element has a phase difference layer The opposite side of the polarizer from the polarizer.

As the protective layer, if it is a film excellent in transparency, mechanical strength, thermal stability, moisture shielding property, isotropy, etc., it is not particularly limited. Specific examples include polyester-based films such as polyethylene terephthalate, polyethylene isophthalate, and polybutylene terephthalate; diethyl cellulose and triethyl cellulose Cellulose films such as cellulose; polycarbonate films; acrylic films such as polymethyl (meth)acrylate and polyethyl (meth)acrylate; styrene films such as polystyrene and acrylonitrile-styrene copolymers ; Polyolefin-based films such as cycloolefins, cycloolefin copolymers, polynorbornene, polypropylene, polyethylene, ethylene-propylene copolymers; vinyl chloride-based films; nylon-based, aromatic polyamide-based polyamide-based membranes; amides Imine-based membrane; Bian-based membrane; Polyetherketone-based membrane; Vulcanized polyphenylene-based membrane; Vinyl alcohol-based membrane; Vinylidene chloride-based membrane; Vinyl butyraldehyde-based membrane; Aryl ester-based membrane; Membrane; urethane-based membrane; epoxy-based membrane; polysilicon-based membrane, etc. Among these, in consideration of polarization characteristics and durability, a cellulose-based film having a surface saponified with alkali or the like is particularly preferred. In addition, the protective layer may have an optical compensation function such as a phase difference function.

The protective layer may be an easy bonding process that is applied to the surface adjoining the polarizing element or the phase difference coating layer to improve the adhesion. The easy adhesion treatment is not particularly limited as long as it can improve adhesion, and examples include dry treatments such as primer treatment, plasma treatment, and corona treatment; chemical treatments such as alkali treatment (saponification treatment); low-pressure UV treatment, etc. .

(Touch sensor) The touch sensor has a substrate, a lower electrode disposed on the substrate, an upper electrode facing the lower electrode, and an insulating layer sandwiched between the lower electrode and the upper electrode.

As long as the substrate is a flexible resin film having light permeability, various resin films can be used. For example, as the base material, a film exemplified as the material of the above-mentioned transparent base material can be used.

The lower electrode has, for example, a plurality of small electrodes that are square in plan view. A plurality of small electrodes are arranged in a matrix.

In addition, the plurality of small electrodes are connected to each other by a diagonal electrode adjacent to one of the small electrodes in a diagonal direction to form a plurality of electrode rows. A plurality of electrode rows are connected to each other at the ends, and the capacitance between adjacent electrode rows can be detected.

The upper electrode has, for example, a plurality of small electrodes that are square in plan view. The plurality of small electrodes are arranged at a position where the lower electrode is not arranged in a plan view, and are arranged in a matrix in a complementary manner. That is, the upper electrode and the lower electrode are arranged without a gap in plan view.

In addition, the plurality of small electrodes are connected to each other by the small electrodes adjacent to the other diagonal direction of the small electrodes to form a plurality of electrode rows. A plurality of electrode rows are connected to each other at the ends, and the capacitance between adjacent electrode rows can be detected.

The insulating layer insulates the lower electrode from the upper electrode. As the material for forming the insulating layer, a material generally known as a material for the insulating layer of the touch sensor can be used.

In addition, in the present embodiment, the case where the touch sensor is a so-called projection type electrostatic capacitance type touch sensor has been described, but a film resistor can be used within a range that does not impair the effects of the invention Touch sensors in other ways.

(Shading pattern) The above-mentioned light-shielding pattern may be provided as at least a part of a frame or casing of a window film or a display device using the window film. For example, there are cases where the wiring of the above display device is covered by a light-shielding pattern and is not recognized by the user. The color and/or material of the shading pattern is not particularly limited, and can be formed by a resin substance having various colors such as black, white, and gold. For example, the light-shielding pattern can be formed by mixing resin substances such as acrylic resin, ester resin, epoxy resin, polyurethane, polysiloxane and the like with pigments to achieve color. The material and thickness of the light-shielding pattern can be determined in consideration of the protection and flexibility characteristics of the window film or the display device. Also, these can be used alone or in a mixture of two or more. [Example]

Hereinafter, the present invention will be described in more detail by examples. Unless otherwise specified, "%" and "parts" in the examples refer to mass% and mass parts. First, the evaluation method will be explained.

<Measurement of weight average molecular weight (Mw)> Determination by gel permeation chromatography (GPC) (1) Pretreatment method The DMF dissolution solution (10 mmol/L lithium bromide solution) of the polyamidoamide resin obtained in the examples and comparative examples was added so as to have a concentration of 2 mg/mL, and the mixture was stirred at 80° C. for 30 minutes. After heating and cooling, a 0.45 μm membrane filter was used as the measurement solution. (2) Measurement conditions Column: TSKgel α-2500((7)7.8 mm diameter×300 mm)×1 piece, α-M((13)7.8 mm diameter×300 mm)×2 pieces made by Tosoh Corporation Dissolution solution: DMF (addition of 10 mmol/L lithium bromide) Flow rate: 1.0 mL/min Detector: RI (Refractive Index, refractive index) detector Column temperature: 40℃ Injection volume: 100 μL Molecular weight standard: standard polystyrene

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

<Measurement of light transmittance> Using the ultraviolet-visible near-infrared spectrophotometer V-670 manufactured by Nippon Spectroscopy Co., Ltd., the transmittance of the optical film obtained in the examples and comparative examples to light of 300 to 800 nm was measured. According to the measurement results, read the light transmittance at 375 m and 420 nm.

<Measurement of Yellowness (YI)> In accordance with JIS K 7373: 2006, the yellowness (YI, Yellow Index) of the optical films obtained in Examples and Comparative Examples was measured using an ultraviolet-visible near-infrared spectrophotometer V-670 manufactured by Japan Spectroscopy Co., Ltd. After the background measurement was carried out without a film, the film was set in a sample holder, and the transmittance measurement for light of 300 to 800 nm was performed, and 3 stimulation values (X, Y, Z) were obtained. YI is calculated based on the following formula. YI＝100×(1.2769X－1.0592Z)/Y

<Measurement of ΔYI> The optical films obtained in Examples and Comparative Examples were subjected to the following light resistance test, and the amount of change in YI before and after the light resistance test was calculated as ΔYI. (Light resistance test) Atlas UVCON (lamp: UVB313 nm) manufactured by Atlas was used to irradiate light on the surface not in contact with the support (substrate) during film formation, and the film was irradiated with light for 24 hours. The smaller the ΔYI value, the more the change in yellowness (YI) before and after the light resistance test is smaller, and the light resistance is higher.

<Example 1> [Preparation of Polyamide Amide Imide Resin (1)] Under a nitrogen atmosphere, to a 1 L separable flask equipped with a stirring wing, add 2,2'-bis(trifluoromethyl)benzidine (TFMB) 14.20 g (44.34 mmol) and N,N-dimethyl Acetamide (DMAc) 250.00 g, and stirred at room temperature while dissolving TFMB in DMAc. Next, 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA) 7.96 g (18.00 mmol) was added to the flask, and stirred at room temperature for 3 hours. Thereafter, 5.62 g (26.88 mmol) of 2,5-thiophenediyl chloride (TDOC) was added to the flask, and stirred at room temperature for 1 hour. Then, 2.50 g (26.84 mmol) of 4-picoline and 12.80 g (125.38 mmol) of acetic anhydride were added to the flask, and after stirring at room temperature for 30 minutes, the temperature was raised to 70°C using an oil bath, and the mixture was further stirred for 3 hours. The reaction solution is obtained. The obtained reaction liquid was cooled to room temperature, poured into a large amount of methanol in a linear form, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 60°C to obtain a polyamidoamide resin (1). The weight average molecular weight (Mw) of the polyamide amide imide resin (1) was 740,000.

[Manufacture of optical film (1)] To the obtained polyamidoimide resin (1), DMAc was added so that the concentration became 10% by mass to produce a polyamidoamide imide varnish (1). Using an applicator so that the thickness of the independent film becomes 50 μm, apply the obtained polyamide amide imide varnish (1) to a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") The surface was smoothed and dried at 50°C for 30 minutes, and then dried at 140°C for 15 minutes to obtain an independent film. The independent film was fixed to a gold frame, and then dried at 200°C for 60 minutes to obtain an optical film (1) with a thickness of 45 μm. The light transmittance and ΔYI of the optical film (1) were measured according to the above measurement method. As a result, the light transmittance at 375 nm was 0%, the light transmittance at 420 nm was 85%, and the ΔYI was 0.7.

<Comparative Example 1> [Preparation of Polyamide Amide Imide Resin (2)] Under a nitrogen atmosphere, to a 1 L separable flask equipped with a stirring wing, add 2,2'-bis(trifluoromethyl)benzidine (TFMB) 14.29 g (44.62 mmol) and N,N-dimethyl Acetamide (DMAc) 250 g, and stirred at room temperature while dissolving TFMB in DMAc. Next, 8.41 g (18.11 mol) of 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA) was added to the flask, and stirred at room temperature for 3 hours. Thereafter, terephthaloyl chloride (TPC) 5.49 g (27.04 mmol) was added to the flask, and stirred at room temperature for 1 hour. Then, 2.52 g (27.06 mmol) of 4-methylpyridine and 12.88 g (126.16 mmol) of acetic anhydride were added to the flask, and after stirring at room temperature for 30 minutes, the temperature was raised to 70°C using an oil bath, and the mixture was further stirred for 3 hours. The reaction solution is obtained. The obtained reaction liquid was cooled to room temperature, poured into a large amount of methanol in a linear form, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and washed with methanol. Next, the precipitate was dried under reduced pressure at 60°C to obtain a polyamidoamide resin (2). The weight average molecular weight (Mw) of the polyamide amide imide resin (2) was 290,000.

[Manufacture of optical film (2)] To the obtained polyamidoimide resin (2), DMAc was added so that the concentration became 10% by mass to produce a polyamidoamide imide varnish (2). Using an applicator so that the thickness of the independent film becomes 55 μm, apply the obtained polyamide amide imide varnish (2) to a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") The surface was smoothed and dried at 50°C for 30 minutes, and then dried at 140°C for 15 minutes to obtain an independent film. The independent film was fixed to a gold frame, and then dried at 200°C for 60 minutes to obtain an optical film (2) with a thickness of 50 μm. The light transmittance and ΔYI of the optical film (2) were measured according to the above measurement method. As a result, the light transmittance at 375 nm was 25%, the light transmittance at 420 nm was 87%, and ΔYI was 3.0.

<Example 2> [Preparation of Polyamide Amide Imide Resin (3)] Under a nitrogen atmosphere, to a 1 L separable flask equipped with a stirring wing, add 2,2'-bis(trifluoromethyl)benzidine (TFMB) 16.56 g (51.70 mmol) and N,N-dimethyl Acetamide (DMAc) 313.57 g, and stirred at room temperature while dissolving TFMB in DMAc. Next, 13.4 g (31.33 mmol) of 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA) was added to the flask, and stirred at room temperature for 3 hours. Thereafter, 4.37 g (20.89 mmol) of 2,5-thiophenediyl chloride (TDOC) was added to the flask, and stirred at room temperature for 1 hour. Then, 1.95 g (20.89 mmol) of 4-methylpyridine and 22.39 g (219.34 mmol) of acetic anhydride were added to the flask, and after stirring at room temperature for 30 minutes, the temperature was raised to 70°C using an oil bath, and the mixture was further stirred for 3 hours. The reaction solution is obtained. The obtained reaction liquid was cooled to room temperature, poured into a large amount of methanol in a linear form, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and washed with methanol. Next, the precipitate was dried under reduced pressure at 60°C to obtain a polyamidoamide resin (3). The weight average molecular weight (Mw) of the polyamide amide imide resin (3) was 298,000.

[Manufacture of optical film (3)] To the obtained polyamidoamide resin (3), DMAc was added so that the concentration became 10% by mass to prepare a polyamidoamide resin varnish (3). Using an applicator so that the thickness of the independent film becomes 50 μm, apply the obtained polyamide amide imide varnish (3) to a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") The surface was smoothed and dried at 50°C for 30 minutes, and then dried at 140°C for 15 minutes to obtain an independent film. The independent film was fixed to the gold frame, and then dried at 200°C for 60 minutes to obtain an optical film (3) with a thickness of 50 μm. The light transmittance and ΔYI of the optical film (3) were measured according to the above measurement method. As a result, the light transmittance at 375 nm was 1%, the light transmittance at 420 nm was 87%, and the ΔYI was 0.7.

<Example 3> [Preparation of Polyamide Amide Imide Resin (4)] Under a nitrogen atmosphere, to a 1 L separable flask equipped with a stirring wing, add 2,2'-bis(trifluoromethyl)benzidine (TFMB) 19.19 g (59.91 mmol) and N,N-dimethyl Acetamide (DMAc) 313.57 g, and stirred at room temperature while dissolving TFMB in DMAc. Next, 5.43 g (12.23 mmol) of 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA) was added to the flask, and stirred at room temperature for 3 hours. Thereafter, 10.22 g (48.91 mmol) of 2,5-thiophenediyl chloride (TDOC) was added to the flask, and stirred at room temperature for 1 hour. Next, 4.56 g (48.91 mmol) of 4-picoline and 8.74 g (85.59 mmol) of acetic anhydride were added to the flask, and after stirring at room temperature for 30 minutes, the temperature was raised to 70°C using an oil bath, and the mixture was further stirred for 3 hours. The reaction solution is obtained. The obtained reaction liquid was cooled to room temperature, poured into a large amount of methanol in a linear form, and the deposited precipitate was taken out, immersed in methanol for 6 hours, and washed with methanol. Next, the precipitate was dried under reduced pressure at 60°C to obtain a polyamidoamide resin (4). The weight average molecular weight (Mw) of the polyamidoimide resin (4) was 283,000.

[Manufacture of optical film (4)] To the obtained polyamidoamide resin (4), DMAc was added so that the concentration became 10% by mass to prepare a polyamidoamide resin varnish (4). Using an applicator so that the thickness of the independent film becomes 50 μm, apply the obtained polyamide amide imide varnish (4) to a polyester substrate (manufactured by Toyobo Co., Ltd., trade name "A4100") The surface was smoothed and dried at 50°C for 30 minutes, and then dried at 140°C for 15 minutes to obtain an independent film. The independent film was fixed to a gold frame, and then dried at 200° C. for 60 minutes to obtain an optical film (4) with a thickness of 50 μm. The light transmittance and ΔYI of the optical film (4) were measured according to the above measurement method. As a result, the light transmittance at 375 nm was 0%, the light transmittance at 420 nm was 84%, and the ΔYI was 0.7.

Table 1 shows the structural unit of the polyimide amide imine resin, the light transmittance at 375 nm and 420 nm of the optical film, and ΔYI. Furthermore, in the structural units, the numbers in parentheses indicate the ratio (content) of each structural unit. For example, in Example 1, it means TDOC units: 6FDA units: TFMB units=60:40:100. [Table 1]

As shown in Table 1, compared to the optical film obtained in Comparative Example 1, the optical films obtained in Examples 1 to 3 were found to be significantly smaller in ΔYI and had excellent light resistance.

Claims (11)

A polyimide amide imide resin, which comprises the structural units represented by formula (1) and formula (2): [化1]

[In Formula (1) and Formula (2), X independently represents a divalent organic group, Y represents a tetravalent organic group, and Z represents a divalent heterocyclic ring]. The polyamidoamide resin according to claim 1, wherein in formula (2), Z is a divalent heterocyclic ring containing a sulfur atom. Polyimide amide imine resin as in claim 1 or 2, wherein in formula (2), Z is a divalent heterocyclic ring represented by formula (a): [Chem 2]

[In formula (a), R ^a and R ^b independently represent a hydrogen atom, a C 1-6 alkyl group, a C 1-6 alkoxy group or a C 6-12 aryl group, R ^a and R ^b may be bonded to each other, and the hydrogen atoms contained in R ^a and R ^b may be independently substituted by halogen atoms, respectively, * indicates a bonding bond]. The polyimide amide imide resin according to any one of claims 1 to 3, wherein the content of the structural unit represented by the formula (2) is 0.1 to 1 mol relative to the structural unit 1 represented by the formula (1) 10 moles. An optical film containing the polyamidoamide resin according to any one of claims 1 to 4. An optical film comprising a polyimide amide imide resin containing structural units represented by formula (1) and formula (2b): [化3]

[In formula (1) and formula (2b), X and L independently represent a divalent organic group, and Y represents a tetravalent organic group], and the light transmittance at a wavelength of 420 nm is 70% or more, and at a wavelength of 375 nm The light transmittance is below 5%. The optical film according to claim 6, wherein the content of the ultraviolet absorber in the optical film is less than 1 part by mass with respect to 100 parts by mass of the polyamidoamide resin. The optical film according to claim 6 or 7, wherein in formula (2b), L is a divalent heterocyclic ring. A flexible display device provided with the optical film according to claim 5 or the optical film according to any one of claims 6 to 8. As in the flexible display device of claim 9, it is further provided with a touch sensor. The flexible display device according to claim 9 or 10 further includes a polarizing plate.