TW202031729A - Resin composition - Google Patents

Abstract

The subject of the present invention is to provide a resin composition with less blue tint of reflected light even if it contains nano-sized silica particles. The solution of the present invention is a resin composition comprising a polyamide-imide resin and silica particles with a primary particle size of 5-50 nm, the silica particles satisfying the relations of formulas (1) to (3): L* ≥ 80 (1), -3.0 ≤ a* ≤ 3.0 (2), 7.5 ≤ b* ≤ 20 (3); in formula (1)- formula (3), L*, a*, and b* respectively indicate the chromaticity coordinates of L*, a* and b* of the L*a*b* chromaticity system of the silica particles precipitated by heating the silica sol with the silica particles dispersed in the atmosphere at a temperature of 200 DEG C for 1 hour.

Description

Resin composition

The present invention relates to a resin composition capable of forming an optical film used as a front panel of an image display device, etc., and the optical film.

Image display devices such as liquid crystal display devices and organic EL (Electroluminescence) display devices are widely used for various applications such as mobile phones and smart watches. The industry has always used glass as the front panel of such image display devices. However, the glass is very rigid and easy to break, so it is difficult to use it as a front panel material such as a flexible display. As one of the materials to replace glass, there are polyimide resins or polyimide resins, and the industry continues to study optical films using these resins (for example, Patent Document 1). [Prior Technical Literature] [Patent Literature]

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

[The problem to be solved by the invention]

In addition to polyimide resin or polyimide imide resin, optical films may also include nano-sized silica particles in order to improve the elastic modulus of the optical film. However, according to the inventor’s research, due to the use of nano-sized silicon dioxide particles dispersed in the optical film, short-wavelength light is preferentially scattered, or the reflectance of the film surface with bluish light is increased , The reflected light appears bluish. If such an optical film is applied to a display device, the visibility decreases. Among them, it can be seen that in the polyamide imide resin, there are amide bonds that can be hydrogen bonded in the structure. Therefore, the higher dispersibility of silica particles is used to easily scatter light and reflect light more easily. Bluish.

Therefore, the object of the present invention is to provide a resin composition that can form a less bluish optical film that reflects light on the film surface even if it contains nano-sized silicon dioxide particles, and the optical film. [Technical means to solve the problem]

The inventors of the present invention made diligent studies to solve the above-mentioned problems. As a result, they found that in an optical film containing polyamideimide resin and silica particles with a primary particle size of 5-50 nm, if the dioxide is dispersed The color coordinates L*, a* and b* of the silica particles precipitated in the L*a*b* color system in the L*a*b* color system are specified in the range of the silica sol of silicon particles heated at 200℃ for 1 hour in the atmosphere Therefore, the above-mentioned problems can be solved, and the present invention can be completed. That is, the following aspects are included in the present invention.

[1] A resin composition comprising a polyamideimide resin and silica particles with a primary particle size of 5-50 nm, and the silica particles satisfy the relationship of formula (1) to formula (3) : L*≧80 (1) -3.0≦a*≦3.0 (2) 7.5≦b*≦20 (3) [In formulas (1) to (3), L*, a*, and b* respectively represent the second precipitation when the silica sol dispersed with the silica particles is heated in the atmosphere at a temperature of 200°C for 1 hour The color coordinates L*, a* and b* of silica particles in the L*a*b* color system]. [2] The resin composition as described in [1], wherein the polyamide imide resin contains: a structural unit derived from a tetracarboxylic acid compound including a structural unit derived from an aromatic tetracarboxylic acid compound, and The structural unit derived from the dicarboxylic acid compound of the structural unit derived from the aromatic dicarboxylic acid compound, and the sum of the structural unit derived from the aromatic tetracarboxylic acid compound and the structural unit derived from the aromatic dicarboxylic acid compound The molar amount is 10 molar% or more with respect to the total molar amount of the structural unit derived from the tetracarboxylic acid compound and the structural unit derived from the dicarboxylic acid compound. [3] The resin composition as described in [1] or [2], wherein the polyimide resin contains a halogen atom. [4] The resin composition as described in any one of [1] to [3], wherein the weight average molecular weight of the polyimide resin is 150,000 or more in terms of polystyrene. [5] The resin composition according to any one of [1] to [4], wherein the silicon dioxide particles are surface-modified silicon dioxide particles. [6] The resin composition according to any one of [1] to [5], wherein the content of silicon dioxide particles is 0.1 to 60 parts by mass relative to 100 parts by mass of the solid content of the resin composition. [7] The resin composition as described in any one of [1] to [6], which further contains a solvent. [8] An optical film formed from the resin composition as described in any one of [1] to [7]. [9] The optical film as described in [8], wherein the thickness of the optical film is 10-100 μm. [10] The resin composition according to any one of [1] to [7], wherein the silica particles are formed by dispersing silica sol in methanol. [11] The resin composition as described in [7], wherein the silica particles are formed of methanol-dispersed silica sol replaced with the same solvent as the above-mentioned solvent. [Effects of Invention]

Even if the resin composition of the present invention contains nano-sized silicon dioxide particles, it can form an optical film with less bluish reflection on the surface of the film.

[Resin composition] The optical film of the present invention comprises a polyamideimide resin and silica particles with a primary particle size of 5-50 nm.

＜Polyamide imide resin＞ The polyamidoimide resin contained in the resin composition of the present invention is a polymer containing both a repeating structural unit containing an amido group and a repeating structural unit containing an amido group. The polyamidoimide resin may include structural units derived from diamine compounds, structural units derived from tricarboxylic acid compounds, and arbitrarily selected from structural units derived from dicarboxylic acid compounds and derived from tetracarboxylic acid The resin containing at least one structural unit in the structural unit of the compound may also contain a structural unit derived from a diamine compound, a structural unit derived from a dicarboxylic acid compound, a tetracarboxylic acid compound, and optionally a tricarboxylic acid compound. Resins of structural units of carboxylic acid compounds.

In one embodiment of the present invention, the polyimide resin is preferably a resin containing structural units derived from diamine compounds, structural units derived from dicarboxylic acid compounds, and structural units derived from tetracarboxylic acid compounds , And more preferably have a structural unit represented by formula (1) and a structural unit represented by formula (2).

[化1]

The structural unit represented by formula (1) is a structural unit formed by the reaction between a tetracarboxylic acid compound and a diamine compound, and the structural unit represented by formula (2) is a structure formed by the reaction between a dicarboxylic acid compound and a diamine compound unit.

In the formula (2), Z is a divalent organic group independently of each other, and preferably represents a hydrocarbon group with 4 to 40 carbons that can be substituted by a hydrocarbon group with 1 to 8 carbons or a hydrocarbon group with 1 to 8 carbons substituted by fluorine The divalent organic group is more preferably a divalent organic group having a cyclic structure and having a carbon number of 4 to 40 which can be substituted by a hydrocarbon group having 1 to 8 carbons or a hydrocarbon group having 1 to 8 carbons substituted by fluorine. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. As the organic group of Z, the following formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), Among the bonding bonds of the groups represented by formula (28) and formula (29), two non-adjacent groups substituted with hydrogen atoms and a divalent chain hydrocarbon group with 6 or less carbon atoms are used as the heterocyclic structure of Z A group having a thiophene ring skeleton can be exemplified. From the viewpoint of easily suppressing the yellowness (lowering YI value) of the optical film formed from the resin composition, it is preferable to exemplify the formulas (20) to (28) The group, and the group with a thiophene ring skeleton.

[式(20')～式(29')中，W¹ 及*係如於式(20)～式(29)中所定義]。 再者，式(20)～式(29)及式(20')～式(29')中之環上之氫原子可經碳數1～8之烴基或經氟取代之碳數1～8之烴基、碳數1～6之烷氧基、或經氟取代之碳數1～6之烷氧基取代。As the organic group of Z, it is more preferably formula (20'), formula (21'), formula (22'), formula (23'), formula (24'), formula (25'), formula (26') , Formula (27'), formula (28') and formula (29') expressed divalent organic group: [化2]

[In formulas (20') to (29'), W ¹ and * are as defined in formulas (20) to (29)]. Furthermore, the hydrogen atoms in the ring in formulas (20) to (29) and (20') to (29') can be substituted by hydrocarbon groups with 1 to 8 carbons or substituted by fluorine with carbons 1 to 8 The hydrocarbon group, the alkoxy group with 1 to 6 carbons, or the alkoxy group with 1 to 6 carbons substituted by fluorine.

[式(d1)中，R²⁴ 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基或碳數6～12之芳基，R²⁵ 表示R²⁴ 或-C(=O)-*，*表示鍵結鍵]。When the Z of the polyamide imine resin in the formula (2) has a structural unit represented by any one of the above formula (20') to formula (29'), where in the formula (2) When Z has a structural unit represented by the following formula (3a), from the viewpoint of easily improving the film-forming properties of the varnish, it is preferable that the polyimide imide resin has the following in addition to the structural unit Structural unit derived from carboxylic acid represented by formula (d1): [化3]

[In formula (d1), R ²⁴ independently represents a hydrogen atom, an alkyl group having 1 to 6 carbons, an alkoxy group having 1 to 6 carbons, or an aryl group having 6 to 12 carbons, and R ²⁵ represents R ²⁴ or -C(=O)-*, * means bonding key].

In R ²⁴ , as the alkyl group with 1 to 6 carbons, the alkoxy group with 1 to 6 carbons, and the aryl group with 6 to 12 carbons, respectively, the ones with 1 to 6 carbons in the formula (3) The alkyl group, the alkoxy group having 1 to 6 carbons, or the aryl group having 6 to 12 carbons are exemplified. As the structural unit (d1), specifically, a structural unit in which R ²⁴ and R ²⁵ are both hydrogen atoms (a structural unit derived from a dicarboxylic acid compound), R ²⁴ is a hydrogen atom, and R ²⁵ represents -C (=O)-*The structural unit (the structural unit derived from the tricarboxylic acid compound), etc.

[式(3a)中，R^a 及R^b 相互獨立地表示鹵素原子、碳數1～6之烷基、碳數1～6之烷氧基、或碳數6～12之芳基，R^a 及R^b 中所含之氫原子可相互獨立地經鹵素原子取代，A、m及*分別與式(3)中之A、m及*相同，t為0～4之整數，u為0～4之整數]， 更佳為式(3)所表示之結構單元： [化5]

[式(3)中，R¹ ～R⁸ 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基、或碳數6～12之芳基，R¹ ～R⁸ 中所含之氫原子可相互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之一價烴基， m為0～4之整數， *表示鍵結鍵]。The polyamideimide resin in the present invention may include a plurality of Z as the Z in the formula (2), and the plurality of Z may be the same or different from each other. Among them, from the viewpoint of easily improving the optical properties, elastic modulus, and flex resistance of the resin in the present invention, Z in formula (2) is preferably represented by formula (3a): [化4] ]

[In the formula (. 3A), R ^a and R ^b each independently represent a halogen atom, an alkyl group having 1 to 6 carbon atoms, the alkoxy group having a carbon number of 1 to 6, carbon atoms, or an aryl group of 6 to 12, R ^a The hydrogen atoms contained in and R ^b can be independently substituted by halogen atoms. A, m and * are the same as A, m and * in formula (3), t is an integer from 0 to 4, and u is from 0 to Integer of 4], more preferably the structural unit represented by formula (3): [化5]

[In formula (3), R ¹ to R ⁸ independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, R ¹ The hydrogen atoms contained in ~R ⁸ can be independently substituted by 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, carbon that can be substituted by a halogen atom A monovalent hydrocarbon group with a number of 1-12, m is an integer of 0-4, and * represents a bonding bond].

In formula (3a), the bonding bond of each benzene ring is based on -A-, which can be bonded to any of ortho, meta or para positions, preferably can be bonded to meta or para Bit. R ^a and R ^b independently represent a halogen atom, an alkyl group having 1 to 6 carbons, an alkoxy group having 1 to 6 carbons, or an aryl group having 6 to 12 carbons. In the formula (3), t and u are preferably 0. When t and/or u are 1 or more, R ^a and R ^b independently of each other preferably represent an alkyl group having 1 to 6 carbon atoms, more preferably It represents an alkyl group having 1 to 3 carbon atoms. In the R ^a and R ^b in the formula (3a), as a halogen atom, an alkyl group having 1 to 6 carbons, an alkoxy group having 1 to 6 carbons, and an aryl group having 6 to 12 carbons, each can be listed as In the formula (3), the halogen atom, the alkyl group having 1 to 6 carbons, the alkoxy group having 1 to 6 carbons, or the aryl group having 6 to 12 carbons are exemplified.

In the formula (3a), t and u are independently an integer of 0-4, preferably an integer of 0-2, more preferably 0 or 1, and even more preferably 0.

In formula (3) and formula (3a), 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 that it is easier to improve the flexibility resistance of the optical film, it is more Preferably it represents -O- or -S-, and more preferably represents -O-. In the formula (3), R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbons, and a carbon number of 1 to Alkoxy group of 6 or aryl group of 6-12 carbons. Examples of alkyl groups having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, second butyl, tertiary butyl, n-pentyl, and 2-methyl Butyl, 3-methylbutyl, 2-ethylpropyl, n-hexyl, etc. Examples of alkoxy groups having 1 to 6 carbon atoms include: methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tertiary butoxy, and pentoxy , Hexyloxy and cyclohexyloxy, etc. Examples of aryl groups having 6 to 12 carbon atoms include phenyl, tolyl, xylyl, naphthyl, and biphenyl. From the viewpoint of the surface hardness and flexibility of the optical film, R ¹ to R ⁸ independently of each other preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably represent a hydrogen atom or a carbon number of 1 to 3 The alkyl group further preferably represents a hydrogen atom. Here, the hydrogen atoms contained in R ¹ to R ⁸ may be substituted with halogen atoms independently of each other. R ⁹ represents a hydrogen atom, a monovalent hydrocarbon group of 1 to 12 carbons which may be substituted with a halogen atom. Examples of monovalent hydrocarbon groups with 1 to 12 carbon atoms include methyl, ethyl, n-propyl, isopropyl, n-butyl, second butyl, tertiary butyl, n-pentyl, 2-methyl Butyl, 3-methylbutyl, 2-ethylpropyl, n-hexyl, n-heptyl, n-octyl, tertiary octyl, n-nonyl and n-decyl, etc., which can be substituted by halogen atoms . As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, etc. are mentioned. As one embodiment of the present invention, the polyimide resin may include a plurality of A, and the plurality of A may be the same or different.

In formulas (3) and (3a), m is an integer in the range of 0-4, and if m is within this range, the flexural resistance or elastic modulus of the optical film is good. Furthermore, in formula (3) and formula (3a), m is preferably an integer in the range of 0-3, more preferably an integer in the range of 0-2, more preferably 0 or 1, and particularly preferably 0. If m is in this range, the flexural resistance or elastic modulus of the optical film is good, and the availability of raw materials is relatively good. The structural unit represented by formula (3a) where m is 0 is, for example, a structural unit derived from terephthalic acid or isophthalic acid, and the structural unit is preferably one in which m is 0 and u is 0 in formula (3a) Structural units. In addition, Z may include one or more of the structural units represented by formula (3) and formula (3a), from the viewpoint of improving the elastic modulus and flexibility resistance of the optical film, and reducing the yellowness (YI value) In other words, two or more structural units with different values of m may also be included, preferably two structural units with different values of m.

From the viewpoint of improving the elastic modulus and flex resistance of the optical film and reducing the yellowness (YI value), it is preferable to include the structural unit represented by the formula (3) where m in the formula (3) is 0, More preferably, in addition to the structural unit, the structural unit represented by formula (3) in which m is 1 is further included.

所表示之結構單元。於該情形時，光學膜可發揮較高之表面硬度，同時具有較高之耐撓曲性，可降低黃色度。In a suitable embodiment of the present invention, the formula (3) or formula (3a) is a structural unit with m=0 and u=0. In a more preferable embodiment of the present invention, the polyimide resin It includes structural units in which m in formula (3) is 0 and R ⁵ to R ⁸ are hydrogen atoms. Furthermore, the structural unit and formula (3') can also be used in combination: [化6]

Indicates the structural unit. In this case, the optical film can exert a higher surface hardness and at the same time have a higher flexural resistance, which can reduce the yellowness.

In a suitable embodiment of the present invention, with respect to the total of the structural unit represented by formula (1) and the structural unit represented by formula (2) of the polyamideimide resin, m is 0-4 The ratio of the structural unit represented by formula (3) or formula (3a) is preferably 20 mol% or more, more preferably 30 mol% or more, still more preferably 40 mol% or more, and still more preferably 50 mol% or more, more preferably 60 mol% or more, and preferably 90 mol% or less, more preferably 85 mol% or less, and still more preferably 80 mol% or less. With respect to the total of the structural unit represented by formula (1) and the structural unit represented by formula (2) in the polyamide imide resin, if m is 0-4, formula (3) or formula ( If the ratio of the structural unit represented by 3a) is more than the above lower limit, the optical film can exhibit higher surface hardness, and the flexural resistance or elastic modulus can be excellent. With respect to the total of the structural unit represented by formula (1) and the structural unit represented by formula (2) in the polyamide imide resin, if m is 0-4, formula (3) or formula ( The ratio of the structural unit represented by 3a) is less than the above upper limit, and the resin composition can be reduced by suppressing the thickening caused by the hydrogen bond between the amide bonds derived from the formula (3) or the formula (3a) The viscosity is suppressed to be low, and the optical film can be processed easily.

In a suitable implementation aspect of the present invention, with respect to the total of the structural unit represented by formula (1) and the structural unit represented by formula (2) of the polyamide imide resin, m is 1 to 4 The ratio of the structural unit represented by formula (3) or formula (3a) is preferably 2 mol% or more, more preferably 4 mol% or more, still more preferably 6 mol% or more, and particularly preferably 8 Mole% or more, and preferably 70 mol% or less, more preferably 50 mol% or less, further preferably 30 mol% or less, still more preferably 15 mol% or less, and particularly preferably 12 mol% %the following. With respect to the sum of the structural unit represented by formula (1) and the structural unit represented by formula (2) in the polyamide imide resin, if m is 1 to 4, formula (3) or formula ( If the ratio of the structural unit represented by 3a) is more than the above lower limit, the optical film can exhibit higher surface hardness and the flexural resistance is further improved. With respect to the sum of the structural unit represented by formula (1) and the structural unit represented by formula (2) in the polyamide imide resin, if m is 1 to 4, formula (3) or formula ( The ratio of the structural unit represented by 3a) is less than the above upper limit, and the resin composition can be reduced by suppressing the thickening caused by the hydrogen bond between the amide bonds derived from the formula (3) or the formula (3a) The viscosity is suppressed to be low, and the optical film can be processed easily. Furthermore, the ratio of the structural unit represented by the formula (3) or the formula (3a) can be measured using ¹ H-NMR (Nuclear Magnetic Resonance, nuclear magnetic resonance), or can also be calculated based on the addition ratio of the raw materials.

In a suitable embodiment of the present invention, Z in the polyamideimide resin is preferably 30 mol% or more, more preferably 50 mol% or more, and even more preferably 70 mol% or more It is expressed by formula (3) or formula (3a) when m is 0 to 4. If the above lower limit of Z in the polyimide resin is expressed by formula (3) or formula (3a) when m is 0-4, the optical film can exhibit higher surface hardness , At the same time, it has high flexibility. Furthermore, it is preferable that Z in the polyimide imine resin is preferably 100 mol% or less, which is represented by formula (3) or formula (3a) when m is 0-4. If the above upper limit value of Z in the polyimide resin is represented by formula (3) or formula (3a) when m is 0 to 4, it is suppressed that m is derived from 0 to In the case of 4, the viscosity increase caused by the hydrogen bonds between the amide bonds of formula (3) or formula (3a) can suppress the viscosity of the resin composition to be low, and the optical film can be easily processed.

In a suitable implementation aspect of the present invention, Z in the polyamideimide resin is preferably 5 mol% or more, more preferably 8 mol% or more, and still more preferably 10 mol% or more , It is particularly preferable that 12 mol% or more is expressed by formula (3) or formula (3a) when m is 1 to 4. If the above lower limit of Z in the polyimide resin is represented by formula (3) or formula (3a) when m is 1 to 4, the optical film can exhibit higher surface hardness , At the same time, it has high flexibility. In addition, it is preferable that Z in the polyimide resin is preferably 90 mol% or less, more preferably 70 mol% or less, further preferably 50 mol% or less, and particularly preferably 30 mol% % Or less is expressed by formula (3) or formula (3a) when m is 1 to 4. If the above upper limit of Z in the polyimide imine resin is represented by formula (3) or formula (3a) when m is 1 to 4, it can be suppressed from m to 1 to In the case of 4, the viscosity increase caused by the hydrogen bonds between the amide bonds of formula (3) or formula (3a) can suppress the viscosity of the resin composition to be low, and the optical film can be easily processed. Furthermore, the ratio of the structural unit represented by the formula (3) or the formula (3a) in the polyimide resin can be measured using ¹ H-NMR, or can also be calculated based on the addition ratio of the raw materials.

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

[化7]

In formulas (10) to (18), * represents a bonding bond, and V ¹ , V ² and V ³ independently represent a single bond, -O-, -S-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -, -CO- or -N(Q)-. Here, Q represents a monovalent hydrocarbon group with 1 to 12 carbons which may be substituted with a halogen atom. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms include the same as those exemplified above as R ⁹ in the formula (3). 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 position of V ¹ and V ^{2 with} respect to each ring, and the bonding position of V ² and V ³ with each ring are preferably meta or para, and more preferably para. Examples of the monovalent hydrocarbon group having 1 to 12 carbon atoms which may be substituted with a halogen atom include those exemplified in the above in formula (3).

Among the bases represented by formulas (10) to (18), from the viewpoint of surface hardness and flex resistance of the optical film, formulas (13), (14), (15), and The groups represented by formula (16) and formula (17) are more preferably groups represented by formula (14), formula (15) and formula (16). In addition, V ¹ , V ² and V ³ are independently of each other from the viewpoint of the surface hardness and flexibility of the optical film, preferably a single bond, -O- or -S-, more preferably a single bond or -O- .

[式(4)中，R¹⁰ ～R¹⁷ 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基、或碳數6～12之芳基，R¹⁰ ～R¹⁷ 中所含之氫原子可相互獨立地經鹵素原子取代，*表示鍵結鍵]。 若式(1)及(2)中之複數個X之至少一部分為式(4)所表示之結構單元，則光學膜可表現出較高之表面硬度，同時可具有較高之透明性。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 structural unit represented by formula (4): [化8]

[In formula (4), R ¹⁰ to R ¹⁷ independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, R ¹⁰ The hydrogen atoms contained in ~R ¹⁷ can be independently substituted by halogen atoms, and * represents a bonding bond]. If at least a part of the plurality of X in formulas (1) and (2) is the structural unit represented by formula (4), the optical film can exhibit higher surface hardness and at the same time have higher transparency.

In formula (4), R ¹⁰ , R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ¹⁶ and R ¹⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbons, and a carbon number of 1 to Alkoxy group of 6 or aryl group of 6-12 carbons. Examples of alkyl groups having 1 to 6 carbons, alkoxy groups having 1 to 6 carbons, or aryl groups having 6 to 12 carbons include the alkyl groups having 1 to 6 carbons in formula (3), and carbon number 1. -6 alkoxy or carbon 6-12 aryl group as exemplified above. R ¹⁰ to R ¹⁷ independently of each other preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbons, and more preferably represent a hydrogen atom or an alkyl group having 1 to 3 carbons. Here, R ¹⁰ to R ¹⁷ are The hydrogen atoms contained can be independently substituted by halogen atoms. As a halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned, for example. R ¹⁰ to R ¹⁷ are independent of each other. From the viewpoints of the surface hardness, transparency, and flex resistance of an optical film containing polyamide imide resin, hydrogen atoms, methyl groups, and fluorine groups are more preferred. , Chloro or trifluoromethyl, and more 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, or fluoro , Chloro or trifluoromethyl, and R ¹¹ and R ¹⁷ are especially methyl or trifluoromethyl.

， 即，複數個X之至少一部分為式(4')所表示之結構單元。於該情形時，光學膜可表現出較高之透明性，同時利用含有氟元素之骨架提高該聚醯胺醯亞胺樹脂對溶劑之溶解性，將樹脂組合物之黏度抑制為較低，可容易地進行光學膜之加工。In a suitable embodiment of the present invention, the structural unit represented by formula (4) is the structural unit represented by formula (4'): [化9]

, That is, at least a part of the plurality of Xs is a structural unit represented by formula (4'). In this case, the optical film can exhibit higher transparency, and at the same time, the fluorine-containing skeleton is used to improve the solubility of the polyamideimide resin in solvents, and the viscosity of the resin composition can be suppressed to be low. Easily process the optical film.

In a suitable embodiment of the present invention, X in the polyamide imide resin is preferably 30 mol% or more, more preferably 50 mol% or more, and more preferably 70 mol% or more. The formula (4), especially the formula (4'). If X in the above range in the above polyamide imide resin is represented by formula (4), especially formula (4'), the optical film can exhibit higher transparency, and at the same time, the The skeleton improves the solubility of the polyamideimide resin in solvents, suppresses the viscosity of the resin composition to be low, and can easily process the optical film. Furthermore, it is preferable that 100 mol% or less of X in the polyimide resin is represented by formula (4), especially formula (4'). X in the polyimide resin can be formula (4), especially formula (4'). The ratio of the structural unit represented by the formula (4) of X in the polyamide imide resin can be measured, for example, using ¹ H-NMR, or can be calculated based on the addition ratio of the raw materials.

In formula (1), Y represents a tetravalent organic group independently of each other, preferably represents a tetravalent organic group with 4 to 40 carbons, and more preferably represents a tetravalent organic group with 4 to 40 carbons having a cyclic structure base. Examples of the cyclic structure include alicyclic, aromatic, and heterocyclic structures. The above-mentioned organic groups are those in which the hydrogen atoms in the organic groups may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. In this case, the carbon number of the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably 1-8. The polyimide resin as one embodiment of the present invention may contain a plurality of Y, and the plurality of Y may be the same or different from each other. As Y, the following formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula ( 28) and the group represented by the formula (29); the hydrogen atom in the group represented by the formula (20) to the formula (29) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and Tetravalent chain hydrocarbon group with carbon number 6 or less.

[化10]

In formulas (20) to (29), * represents a bonding bond, W ¹ represents a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH(CH ₃ )-, -C (CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -Ar-, -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 an arylene group having 6 to 20 carbon atoms in which a hydrogen atom can be substituted with a fluorine atom, and a specific example includes a phenylene group.

Among the bases represented by formula (20) to formula (29), from the viewpoint of the surface hardness and flexural resistance of the optical film, the formula (26), formula (28) or formula (29) is preferred The base expressed is more preferably the base expressed by formula (26). In addition, from the viewpoint of easily suppressing the surface hardness, flex resistance, and yellowness of the optical film, W ¹ is preferably a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -independently of each other. , -CH(CH ₃ )-, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -, more preferably a single bond, -O-, -CH ₂ -, -CH(CH ₃ )-, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -, more preferably a single bond, -C(CH ₃ ) ₂ -or -C(CF ₃ ) ₂ -.

[式(5)中，R¹⁸ ～R²⁵ 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基、或碳數6～12之芳基，R¹⁸ ～R²⁵ 中所含之氫原子可相互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)所表示之結構單元，則光學膜可表現出較高之透明性，同時提高聚醯胺醯亞胺樹脂對溶劑之溶解性，將樹脂組合物之黏度抑制為較低，又，可容易地進行光學膜之加工。In a suitable embodiment of the present invention, at least a part of the plurality of Y in formula (1) is the structural unit represented by formula (5): [化11]

[In formula (5), R ¹⁸ to R ²⁵ independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, R ¹⁸ The hydrogen atoms contained in ~R ²⁵ can be substituted by halogen atoms independently of each other, and * represents a bonding bond]. If at least a part of the plural Y in formula (1) is the structural unit represented by formula (5), the optical film can exhibit higher transparency and at the same time improve the solubility of the polyimide imide resin to solvents , The viscosity of the resin composition is kept low, and the optical film can be processed easily.

In formula (5), R ¹⁸ , R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , R ²⁴ and R ²⁵ independently represent a hydrogen atom, an alkyl group having 1 to 6 carbons, and a carbon number of 1 to Alkoxy group of 6 or aryl group of 6-12 carbons. Examples of alkyl groups having 1 to 6 carbons, alkoxy groups having 1 to 6 carbons, or aryl groups having 6 to 12 carbons include the alkyl groups having 1 to 6 carbons in formula (3), and carbon number 1. -6 alkoxy or carbon 6-12 aryl group as exemplified above. R ¹⁸ to R ²⁵ independently of each other preferably represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and more preferably represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, where R ¹⁸ to R ²⁵ are The hydrogen atoms contained can be independently substituted by halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms. R ¹⁸ to R ²⁵ are independent of each other in terms of easily improving the surface hardness, flex resistance, and transparency of the optical film, and are more preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, More 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, fluoro, chloro, or trifluoromethyl, especially Preferably, R ²¹ and R ²² are methyl or trifluoromethyl.

， 即，複數個Y之至少一部分為式(5')所表示之結構單元。於該情形時，光學膜可具有較高之透明性。In a suitable embodiment of the present invention, the structural unit represented by formula (5) is the structural unit represented by formula (5'): [化12]

, That is, at least a part of the plurality of Y is a structural unit represented by formula (5'). In this case, the optical film can have higher transparency.

In a suitable embodiment of the present invention, Y in the polyimide imine resin is preferably 50 mol% or more, more preferably 60 mol% or more, and still more preferably 70 mol% or more. The formula (5), especially the formula (5'). If Y in the above-mentioned range in the above-mentioned polyamide imide resin is represented by formula (5), especially formula (5'), the optical film can have higher transparency, and the fluorine-containing The skeleton improves the solubility of the polyimide resin to solvents, suppresses the viscosity of the resin composition to be low, and facilitates the production of optical films. Furthermore, it is preferable that 100 mol% or less of Y in the polyimide resin is represented by formula (5), especially formula (5'). The Y in the polyimide resin can be formula (5), especially formula (5'). The ratio of the structural unit represented by the formula (5) of Y in the polyamide imide resin can be measured, for example, using ¹ H-NMR, or can also be calculated based on the addition ratio of the raw materials.

In the above polyimide imine resin, the content of the structural unit represented by formula (2) is preferably 0.1 mol or more relative to 1 mol of the structural unit represented by formula (1), and more preferably 0.5 mol or more, more preferably 1.0 mol or more, particularly preferably 1.5 mol or more, and preferably 6.0 mol or less, more preferably 5.0 mol or less, and still more preferably 4.5 mol or less. If the content of the structural unit represented by formula (2) is more than the above lower limit, the optical film can exhibit higher surface hardness. Moreover, if the content of the structural unit represented by the formula (2) is below the above upper limit, the viscosity increase caused by the hydrogen bond between the amide bonds in the formula (2) can be suppressed, and the viscosity of the resin composition can be reduced , Easy to manufacture optical film.

In addition to the structural units represented by the formula (1) and the formula (2), the polyimide resin may include the structural unit represented by the formula (30) and/or the structural unit represented by the formula (31). [化13]

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

In formula (31), Y ² is a trivalent organic group, preferably an organic group in which the hydrogen atom in the organic group can be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. As Y ² , the above-mentioned formula (20), formula (21), formula (22), formula (23), formula (24), formula (25), formula (26), formula (27), formula ( 28) and any one of the bonding bonds of the group represented by the formula (29) is substituted with a hydrogen atom, and a trivalent chain hydrocarbon group having 6 or less carbon atoms. The polyimide resin as one embodiment of the present invention may include a plurality of Y ² , and the plurality of Y ² may be the same or different from each other.

In formula (30) and formula (31), X ¹ and X ² are independently a divalent organic group, preferably an organic group in which the hydrogen atom in the organic group can be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group. Examples of X ¹ and X ² include the above-mentioned formula (10), formula (11), formula (12), formula (13), formula (14), formula (15), formula (16), and formula (17) , And the group represented by the formula (18); the hydrogen atom in the group represented by the formula (10) to the formula (18) is substituted by a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; and carbon Chain hydrocarbon group with number 6 or less.

In one embodiment of the present invention, the polyimide resin includes structural units represented by formula (1) and formula (2), and as the case may be represented by formula (30) and/or formula (31) The structural unit. In addition, from the viewpoint of the surface hardness and flex resistance of the optical film, in the above-mentioned polyimide resin, the structural units represented by formulas (1) and (2) are based on formulas (1) and (2), and all the structural units represented by formula (30) and formula (31) depending on the situation, preferably 80 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% the above. Furthermore, in the above polyimide resin, the structural units represented by formula (1) and formula (2) are based on formula (1) and formula (2), as well as formula (30) and formula ( 31) All the structural units indicated are usually 100% or less. In addition, the said ratio can be measured using ¹ H-NMR, for example, or it can also be calculated based on the addition ratio of raw materials.

The structural unit represented by formula (1) is a structural unit formed by the reaction between a tetracarboxylic acid compound and a diamine compound, and the structural unit represented by formula (2) is a structure formed by the reaction between a dicarboxylic acid compound and a diamine compound unit. In addition, the structural unit represented by formula (30) is a structural unit formed by the reaction of a tetracarboxylic acid compound and a diamine compound, and the structural unit represented by formula (31) is formed by the reaction of a tricarboxylic acid compound and a diamine compound The structural unit. In one embodiment of the present invention, the structural unit derived from the tetracarboxylic acid compound contained in the polyamide imide resin is as exemplified in Y in formula (1) or Y1 in formula (30), The structural unit derived from the aromatic tetracarboxylic acid compound is included, and the structural unit derived from the dicarboxylic acid compound is as exemplified in Z in formula (2), and the structural unit derived from the aromatic dicarboxylic acid compound is included. The total molar amount of the structural unit derived from the aromatic tetracarboxylic acid compound and the structural unit derived from the aromatic dicarboxylic acid compound is relative to the structural unit derived from the tetracarboxylic acid compound and the structure derived from the dicarboxylic acid compound The total molar amount of the unit is preferably 10 mol% or more, more preferably 20 mol% or more, still more preferably 40 mol% or more, still more preferably 60 mol% or more, and particularly preferably 80 mol% % Or more, and preferably 100 mol% or less. If the total molar amount of the structural unit derived from the aromatic tetracarboxylic acid compound and the structural unit derived from the aromatic dicarboxylic acid compound is within the above range, it is easy to improve the flexibility resistance, surface hardness, and elastic modulus of the optical film And transparency.

Regarding the weight average molecular weight (Mw) of the polyimide resin, in terms of polystyrene, it is preferably 150,000 or more, more preferably 200,000 or more, still more preferably 250,000 or more, even more preferably 300,000 or more, especially It is preferably 350,000 or more, and more preferably 1,000,000 or less, more preferably 800,000 or less, still more preferably 700,000 or less, still more preferably 500,000 or less, and particularly preferably 450,000 or less. If the weight average molecular weight of the polyimide resin is greater than or equal to the above lower limit, the optical film tends to increase the modulus of elasticity, flex resistance, and surface hardness. In addition, if the weight average molecular weight of the polyimide resin is below the above upper limit, the gelation of the resin composition is easily suppressed in the manufacturing process of the optical film, and the aggregation of silica particles is not likely to occur, so it is easy to reduce the optical The reflected light of the film is bluish. Furthermore, in this specification, the weight average molecular weight can be measured by, for example, GPC (Gel Permeation Chromatography, gel permeation chromatography) and can be calculated by standard polystyrene conversion, for example, by the method described in the examples. Figure out.

In a preferred embodiment of the present invention, the polyimide resin contains halogen atoms. Since the polyamideimide resin contains halogen atoms, there is a case in which the yellowness (YI value) of the optical film can be reduced, and there is a tendency to achieve high flexibility and flexibility resistance at the same time. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. From the viewpoints of the reduction in the yellowness of the optical film, that is, the improvement in transparency, the reduction in water absorption, and the flexibility resistance, It is preferably a fluorine atom. Specific examples of the fluorine-containing substituent in the polyamideimide resin include a fluorine group and a trifluoromethyl group.

Regarding the content of the halogen atom in the polyimide resin, in terms of the reduction in yellowness, that is, the increase in transparency, the decrease in water absorption, and the flexural resistance of the optical film, the polyimide resin Based on the mass of the imine resin, it is preferably 1 to 40% by mass, more preferably 3 to 35% by mass, and still more preferably 5 to 32% by mass.

The imidization rate of the polyimide resin is preferably 95-100%, more preferably 97-100%, and still more preferably 98-100%. From the viewpoint of the stability of the resin composition and the mechanical properties of the obtained optical film, the imidization rate is preferably at least the above lower limit. In addition, the imidization rate can be determined by an IR (Infrared Radiation) method, an NMR method, or the like.

In one embodiment of the present invention, the content of the polyimide resin relative to 100 parts by mass of the solid content of the resin composition is preferably 40 parts by mass or more, more preferably 50 parts by mass or more, and Preferably it is 60 parts by mass or more. From the viewpoint that it is easy to improve the impact resistance and flex resistance of the obtained optical film, and it is easy to reduce the bluishness of the reflected light on the film surface, it is preferable that the content of the polyimide resin is the above lower limit the above. Furthermore, the content of the polyimide resin in the optical film is usually 99.9 parts by mass or less with respect to 100 parts by mass of the solid content of the resin composition. In addition, in this specification, the solid content of the resin composition means the total amount of the components obtained by removing the solvent from the resin composition.

[式(3'')中，R¹ ～R⁸ 相互獨立地表示氫原子、碳數1～6之烷基、碳數1～6之烷氧基、或碳數6～12之芳基，R¹ ～R⁸ 中所含之氫原子可相互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， R³¹ 及R³² 相互獨立地為羥基、甲氧基、乙氧基、正丙氧基、正丁氧基或氯原子]The polyimide imine resin can be manufactured using, for example, a tetracarboxylic acid compound, a dicarboxylic acid compound, and a diamine compound as main raw materials. Here, the dicarboxylic acid compound preferably contains at least the formula (3'') Compound. [化14]

[In formula (3''), R ¹ to R ⁸ independently represent a hydrogen atom, an alkyl group with 1 to 6 carbons, an alkoxy group with 1 to 6 carbons, or an aryl group with 6 to 12 carbons, The hydrogen atoms contained in R ¹ to R ⁸ can be independently substituted by halogen atoms, and 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, which can be substituted by a halogen atom The hydrocarbon group with 1-12 carbon atoms, m is an integer of 0-4, R ³¹ and R ³² are independently hydroxyl, methoxy, ethoxy, n-propoxy, n-butoxy or chlorine atom]

In a suitable embodiment, the dicarboxylic acid compound includes a compound represented by formula (3'') where m is 0 or 1, more preferably includes a compound represented by formula (3'') where m is 0, and more It is preferable to include a compound represented by formula (3'') in which m is 0 and a compound represented by formula (3'') in which m is 1. Furthermore, when m is 1 to 4, A is preferably an oxygen atom. In another suitable embodiment, the dicarboxylic acid compound is a compound represented by formula (3'') in which R ³¹ and R ³² are chlorine atoms. In addition, a diisocyanate compound may be used instead of the diamine compound.

Examples of tetracarboxylic acid compounds used in the synthesis of polyimide resins include: aromatic tetracarboxylic acid compounds such as aromatic tetracarboxylic dianhydride; and aliphatic tetracarboxylic acid compounds such as aliphatic tetracarboxylic dianhydride Acid compounds, etc. The tetracarboxylic acid compound may be used alone or in combination of two or more kinds. The tetracarboxylic acid compound may be a tetracarboxylic acid compound related product such as a chlorinated compound other than the dianhydride.

Specific examples of aromatic tetracarboxylic dianhydrides include: non-condensed polycyclic aromatic tetracarboxylic dianhydrides, monocyclic aromatic tetracarboxylic dianhydrides, and condensed polycyclic aromatic tetracarboxylic dianhydrides Acid dianhydride. Examples of non-condensed polycyclic aromatic tetracarboxylic dianhydrides include: 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic acid Dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3' -Biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2, 2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene Yl)diphthalic dianhydride (sometimes described as 6FDA), 1,2-bis(2,3-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxybenzene Base) 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-phenylenedioxy)diphthalic dianhydride, 4, 4'-(Phenylenedioxy)diphthalic dianhydride. In addition, examples of monocyclic aromatic tetracarboxylic dianhydrides include 1,2,4,5-benzenetetracarboxylic dianhydride, and examples of condensed polycyclic aromatic tetracarboxylic dianhydrides include 2,3,6,7-Naphthalenetetracarboxylic dianhydride. Among these, preferred examples include 4,4'-oxydiphthalic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2', 3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride , 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3- Dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenoxyphenyl)propane dianhydride, 4,4'-(hexafluoroisopropylidene)diphthalic acid Anhydride (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-phenylenedioxy)diphthalic dianhydride and 4,4'-(p-phenylenedioxy)di 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 (6FDA), bis(3,4-dicarboxyphenyl)methane Anhydride and 4,4'-(p-phenylenedioxy) diphthalic dianhydride. These can be used individually or in combination of 2 or more types.

As the aliphatic tetracarboxylic dianhydride, cyclic or acyclic aliphatic tetracarboxylic dianhydride can be mentioned. The so-called cyclic aliphatic tetracarboxylic dianhydride is a tetracarboxylic dianhydride having an alicyclic hydrocarbon structure. Specific examples thereof include: 1,2,4,5-cyclohexane tetracarboxylic 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 -En-2,3,5,6-tetracarboxylic dianhydride, dicyclohexyl 3,3'-4,4'-tetracarboxylic dianhydride and their positional isomers. These can be used individually or in combination of 2 or more types. Specific examples of acyclic 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, cyclic aliphatic tetracarboxylic dianhydride and acyclic aliphatic tetracarboxylic dianhydride can be used in combination.

Among the above-mentioned tetracarboxylic dianhydrides, from the viewpoints of high surface hardness, high transparency, high flexibility, high flex resistance, and low coloring properties of the optical film, 4,4'-oxydihydric Phthalic acid dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenyl tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane Anhydride, 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride, and mixtures thereof, more preferably 3,3',4,4'-biphenyltetracarboxylic dianhydride and 4,4'-(hexafluoroisopropylidene)diphthalic dianhydride and mixtures thereof, and more preferably 4,4'-(hexafluoroisopropylidene)diphthalate Anhydride (6FDA).

As the dicarboxylic acid compound used in the synthesis of the polyamide imide resin, it is preferable to use terephthalic acid chloride, and other dicarboxylic acid compounds may also be used. As other dicarboxylic acid compounds, 4,4'-oxybisbenzoic acid and/or its chlorinated compounds can be used. Examples of other dicarboxylic acid compounds include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and these related chlorinated compounds, acid anhydrides, and the like, and two or more of them may be used in combination. Specific examples include: terephthalic acid; isophthalic acid; naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; chains with 8 or less carbon atoms The dicarboxylic acid compound of the formula hydrocarbon and two benzoic acids are connected by single bond, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -or phenylene And the chlorinated compounds. Among these other dicarboxylic acid compounds, terephthalic acid is preferred. As specific examples, 4,4'-oxybis(benzyl chloride) and terephthalate chloride are preferred, and 4,4'-oxybis(benzyl chloride) is more preferred in combination with p- Dimethyl dimethyl chloride is used.

Furthermore, the above-mentioned polyimide resin may be used in addition to the tetracarboxylic acid compound used in the synthesis of the above-mentioned polyimide resin within the range that does not impair various physical properties of the resin composition or the optical film. Furthermore, tetracarboxylic acid, tricarboxylic acid and these anhydrides and derivatives are reacted.

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

As a tricarboxylic acid compound, aromatic tricarboxylic acid, aliphatic tricarboxylic acid, and these related chlorinated compounds, acid anhydride, etc. can be mentioned, You may use in combination of 2 or more types. Specific examples include: 1,3,5-benzenetricarboxylic acid and its chloride, anhydrides of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalenetricarboxylic acid-2,3- Anhydride; phthalic anhydride and benzoic acid are linked by single bond, -O-, -CH ₂ -, -C(CH ₃ ) ₂ -, -C(CF ₃ ) ₂ -, -SO ₂ -or phenylene From the compound.

As the diamine compound used in the synthesis of the polyimide resin, for example, aliphatic diamine, aromatic diamine, and mixtures thereof can be cited. In addition, the term "aromatic diamine" in this embodiment means a diamine in which an amine group is directly bonded to an aromatic ring, and an aliphatic group or other substituents may be contained in a part of its structure. The aromatic ring may be a monocyclic ring or a condensed ring, and examples thereof include a benzene ring, a naphthalene ring, an anthracene ring, and a sulphur ring, but are not limited to these. Among them, a benzene ring is preferred. In addition, the term "aliphatic diamine" means a diamine in which an amine group is directly bonded to an aliphatic group, and an aromatic ring or other substituents may be contained in a part of the structure.

As aliphatic diamines, for example, acyclic aliphatic diamines such as hexamethylene diamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl) Group) cyclohexane, noralkylene diamine and 4,4'-diaminodicyclohexylmethane and other cyclic aliphatic diamines. These can be used individually or in combination of 2 or more types.

Examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene, 2 ,6-Diaminonaphthalene and other aromatic diamines with one aromatic ring, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diamine Diphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,4'-diamino Diphenyl ingot, 3,3'-diaminodiphenyl ingot, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, Bis[4-(4-aminophenoxy)phenyl]sulfurite, bis[4-(3-aminophenoxy)phenyl]sulfurite, 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 (sometimes referred to as TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, 9,9-bis(4-amino) Phenyl) quince, 9,9-bis(4-amino-3-methylphenyl) quince, 9,9-bis(4-amino-3-chlorophenyl) quince, 9,9-bis( Aromatic diamines having two or more aromatic rings, such as 4-amino-3-fluorophenyl) chlorophyll. These can be used individually or in combination of 2 or more types.

As the aromatic diamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,3'- Diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 1,4-bis(4-aminophenoxy)benzene, double [4-(4-Aminophenoxy)phenyl] ash, bis[4-(3-aminophenoxy)phenyl] ash, 2,2-bis[4-(4-aminophenoxy) Yl)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethane) Group)-4,4'-diaminodiphenyl (TFMB), 4,4'-bis(4-aminophenoxy)biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylene, 1,4-bis(4-aminophenoxy) )Benzene, bis[4-(4-aminophenoxy)phenyl] chrysene, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2'-dimethyl Benzidine, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 4,4'-bis(4-aminophenoxy)biphenyl. These can be used individually or in combination of 2 or more types.

Among the above-mentioned diamine compounds, from the viewpoints of high surface hardness, high transparency, high flexibility, high flexibility resistance, and low coloring properties of the optical film, it is preferable to use aromatic compounds having a biphenyl structure. One or more of the group consisting of diamines. More preferably, use selected from 2,2'-dimethylbenzidine, 2,2'-bis(trifluoromethyl)benzidine, 4,4'-bis(4-aminophenoxy)biphenyl and At least one of the group consisting of 4,4'-diaminodiphenyl ether, and more preferably 2,2'-bis(trifluoromethyl)-4,4'-diaminodiphenyl (TFMB).

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

In the production of polyimide resin, the reaction temperature of the diamine compound, the tetracarboxylic acid compound and the dicarboxylic acid compound is not particularly limited, for example, 5 to 350°C, preferably 20 to 200°C, more preferably It is 25～100℃. The reaction time is also not particularly limited, and is, for example, 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 performed under normal pressure and/or inert gas atmosphere while stirring. 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, isopropanol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, 1- Alcohol solvents such as methoxy-2-propanol, 2-butoxyethanol, and propylene glycol monomethyl ether; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, γ- Ester solvents such as valerolactone, propylene glycol methyl ether acetate and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone ; Aliphatic hydrocarbon solvents such as pentane, hexane and heptane; alicyclic hydrocarbon solvents such as ethyl cyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; tetrahydrofuran and dimethoxyethane Ether solvents such as alkane; chlorine-containing solvents such as chloroform and chlorobenzene; amine-based solvents such as N,N-dimethylacetamide and N,N-dimethylformamide; dimethyl sulfide, dimethyl Sulfur-containing solvents such as sulfite and cyclobutyl; 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 production of polyimidimid resins, imidization can be carried out in the presence of an imidization catalyst. Examples of the imidization catalyst include: aliphatic amines such as tripropylamine, dibutylpropylamine, and ethyldibutylamine; N-ethylpiperidine, N-propylpiperidine, N -Alicyclic amines such as butylpyrrolidine, N-butylpiperidine, and N-propylhexahydroazepine (monocyclic); azobicyclo[2.2.1]heptane, azobicyclo[3.2. 1] Octane, azobicyclo[2.2.2]octane, and azobicyclo[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. Moreover, from the viewpoint of facilitating the promotion of the imidization reaction, it is preferable to use the imidization catalyst together with the acid anhydride. The acid anhydride can be exemplified by commonly used acid anhydrides used in the 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.

The polyimide imine resin can be isolated (separated and refined) by conventional methods such as filtration, concentration, extraction, crystallization, recrystallization, column chromatography and other separation methods, or a combination of these separation methods, In a preferred aspect, isolation can be performed by adding a large amount of alcohol such as methanol to the reaction liquid containing the resin to precipitate the resin, and then performing concentration, filtration, drying, and the like.

＜Silica particles＞ The resin composition of the present invention contains silicon dioxide particles with a primary particle size of 5-50 nm. The silicon dioxide particles contained in the resin composition of the present invention satisfy the relationship of formula (1) to formula (3): L*≧80 (1) -3.0≦a*≦3.0 (2) 7.5≦b*≦20 (3) [In formulas (1) to (3), L*, a*, and b* respectively represent the second precipitation when the silica sol dispersed with the silica particles is heated in the atmosphere at a temperature of 200°C for 1 hour The color coordinates L*, a* and b* of silica particles in the L*a*b* color system]. That is, in the present invention, if the silica sol in which the silica particles contained in the resin composition are dispersed is heated in the atmosphere at a temperature of 200°C for 1 hour, the b* of the precipitated silica particles becomes The range from 7.5 to 20 can be yellow. In a suitable embodiment of the present invention, when the resin composition is used to manufacture the optical film, since it is heated to a high temperature, preferably about 200° C. or above, it is preferable to dry the coating film in the atmosphere. When formed, the b* of the silica particles is in the range of 7.5 or more and 20 or less, and the silica particles in the obtained optical film may appear yellow. As a result, when the bluish light (for example, light near 400 nm) is reflected on the surface of the optical film, the dispersed silica particles can partially absorb the light, so that the bluish light affects the surface of the film. Reduced reflectivity can reduce the bluishness of reflected light. Therefore, even if the optical film formed from the resin composition of the present invention is applied to a display device, it can exhibit excellent visibility.

In formula (1), L* is 80 or more, preferably 85 or more, and more preferably 89 or more. If L* is in the above range, the transmittance of the optical film can be improved. Furthermore, in formula (2), the lower limit of a* is -3.0 or more, preferably -2.0 or more, more preferably -1.5 or more, and still more preferably -1.0 or more, and the upper limit of a* is 3.0 or less, which is more It is preferably 2.0 or less, more preferably 1.0 or less, and still more preferably 0 or less. If a* is in the above range, the visibility of the optical film can be improved. In formula (3), the lower limit of b* is 7.5 or more, preferably 8.0 or more, more preferably 9.0 or more, and still more preferably 10.0 or more, and the upper limit of b* is 20 or less, preferably 18 or less, more Preferably, it is 15 or less. If b* is above the above lower limit, the bluishness of the obtained optical film can be further reduced, and if b* is below the above upper limit, excessive yellowing can be suppressed, and the visibility of the optical film can be improved.

The determination of whether silica particles meet the range of formula (1) to formula (3) (sometimes called color measurement) is to use silica sol formed by dispersing silica particles in a dispersing solvent in the atmosphere , Heating at 200°C for 1 hour, by dispersing the silica particles precipitated by the volatilization of the solvent. The method of heating the silica sol is not particularly limited. For example, it can be performed using an electric furnace, a dryer, a heating plate, etc.

The dispersing solvent of silica sol is not particularly limited as long as it can disperse silica particles. For example, it can be from the solvents exemplified above used in the production of polyimide resins. Choose appropriately among them. Among these dispersion solvents, a solvent having a boiling point of 200° C. or less is preferable, an alcohol solvent is more preferable, and methanol is still more preferable. In addition, commercially available silica sols include, for example, the brand name "MA-ST-M" (methanol dispersed silica sol) manufactured by Nissan Chemical Industry Co., Ltd., and the brand name "Methanol silica sol" (methanol silica sol). Dispersed silica sol), brand name "MA-ST-S" (methanol dispersed silica sol), brand name "MT-ST" (methanol dispersed silica sol), brand name "MA-ST-UP" (Methanol Dispersed Silica Sol), Brand Name "MA-ST-L" (Methanol Dispersed Silica Sol), Brand Name "IPA-ST-S" (Isopropanol Dispersed Silica Sol), Brand Name " IPA-ST” (isopropanol dispersed silica sol), brand name “IPA-ST-UP” (isopropanol dispersed silica sol), brand name “IPA-ST-L” (isopropanol dispersed two Silica sol), trade name "IPA-ST-ZL" (isopropanol dispersed silica sol). Among them, from the viewpoint of easily reducing the bluishness of the reflected light of the optical film, the trade name "MA-ST-M" (methanol dispersed silica sol) and the trade name "Methanol silica sol" are preferred. (Methanol dispersed silica sol).

In the silica sol, the content of silica particles relative to the mass of the silica sol is preferably 5-50% by mass, and more preferably 15-45% by mass. Furthermore, the chromaticity can be measured by heating the above silica sol in the atmosphere at a temperature of 200°C for 1 hour, and the precipitated silica particles can be carried out using a color difference meter or the like. For example, it can be performed as described in the examples. Method and proceed.

The primary particle size of the silicon dioxide particles is 5-50 nm, preferably 7 nm or more, more preferably 10 nm or more, still more preferably 15 nm or more, particularly preferably 20 nm or more, and preferably 45 nm or less , And more preferably 40 nm or less. If the primary particle size of the silica particles is in the above range, the bluish tendency of the reflected light of the optical film can be further reduced, and the elastic modulus and optical properties can be easily improved. Furthermore, the primary particle size of the silicon dioxide particles can be measured, for example, by the BET method, or image analysis of a transmission or scanning electron microscope.

Regarding the content of silicon dioxide particles, relative to 100 parts by mass of the solid content of the resin composition, it is preferably 0.1 part by mass or more, more preferably 1 part by mass or more, still more preferably 5 parts by mass or more, and still more preferably 10 Parts by mass or more, more preferably 20 parts by mass or more, particularly more preferably 30 parts by mass or more, and preferably 60 parts by mass or less. If the content of silica particles is within the above range, the bluish tendency of the optical film can be further reduced, and the elastic modulus and optical properties can be easily improved.

By designing a structure that easily decomposes silicon dioxide particles by heating, it can be adjusted to the range of formula (1) to formula (3). As the method, for example, the surface of silicon dioxide particles can be modified with organic groups. Methods etc. The type and modification rate of the organic group for surface modification are not particularly limited, as long as the organic group or modification rate that can be adjusted to the range of formula (1) to formula (3) is appropriately selected. Therefore, from the viewpoint of easily reducing the bluishness of the reflected light of the optical film, as the silica particles contained in the resin composition of the present invention, it is preferable to use surface-modified silica particles. In addition, the surface-modified silica particles have higher dispersibility in resins than pigments. Therefore, by using such surface-modified silica particles, they have a higher level of dispersion in optical films. Dispersion, and can reduce the bluishness of reflected light.

＜Additives＞ The resin composition of the present invention may further include a solvent. The solvent is not particularly limited as long as it can dissolve the polyimide resin. As this solvent, what was exemplified in the above as a solvent used in the manufacture of polyimide resin is mentioned, for example. These solvents can be used alone or in combination of two or more. Among these solvents, amine-based solvents such as N,N-dimethylacetamide and N,N-dimethylformamide, γ-butyrolactone (GBL), and γ-valerolactone are preferred. And other lactone solvents.

The solid content concentration of the resin composition is preferably 1 to 25% by mass, more preferably 5 to 20% by mass. In addition, the so-called solid content concentration means the mass relative to the mass of the resin composition.

The resin composition of the present invention may contain the above-mentioned polyamideimide resin, the above-mentioned silica particles, and other additives other than the above-mentioned solvent. Examples of other additives include leveling agents, antioxidants, ultraviolet absorbers, bluing agents, plasticizers, and surfactants. These other additives can be used alone or in combination of two or more kinds. When the resin composition contains other additives, relative to 100 parts by mass of the resin composition, the content of the other additives may be, for example, 0.001 to 20 parts by mass, preferably about 0.1 to 10 parts by mass.

＜Resin composition＞ The resin composition of the present invention can reduce the bluishness of the reflected light of the optical film formed from the resin composition.

The resin composition of the present invention can be obtained by mixing the above-mentioned polyamideimide resin, the above-mentioned silica particles, and optionally the above-mentioned solvent and other additives. In addition, when the resin composition contains a solvent, the composition may be called a varnish.

When adjusting the resin composition (varnish), a silica sol obtained by dispersing silica particles in a solvent can be used. The dispersing solvent of the silica sol is not particularly limited as long as it can disperse silica particles. For example, it can be selected from those exemplified above in the production of polyimide resins. Choose appropriately among the solvents. Among them, from the viewpoint that it is easier to reduce the bluishness of the reflected light of the optical film, alcohol-based solvents such as methanol are preferred, and the silica particles are more preferably made of silica sol dispersed in methanol. (Hereinafter, sometimes referred to as methanol-dispersed silica sol) silica particles formed by the formation. A commercially available product can be used as the silica sol, and as an example, the commercially available silica sol described in the section of <Silica Particle> can be cited. The methanol-dispersed silica sol can be used for the commercially available products described in the section of "Silica Particles".

When adjusting a resin composition called a varnish, from the viewpoint of the dispersibility of silica particles in the varnish, it is preferable to use a silica sol substituted with the same solvent as the solvent contained in the varnish. Especially from the viewpoint that it is easier to reduce the bluishness of the reflected light of the optical film, the silica particles in the varnish are more preferably silica particles formed by methanol-dispersed silica sol. The methanol-dispersed silica sol It is replaced by the same solvent as the solvent contained in the varnish.

In a preferred embodiment of the present invention, the resin composition of the present invention can be manufactured by a method including the following steps: a solvent replacement step, which uses the same solvent as the solvent contained in the resin composition to disperse the dioxide The silica sol is replaced; the varnish preparation step includes mixing the solvent-replaced silica sol and the polyimide resin. The concentration of the solid content of the methanol-dispersed silica sol may be, for example, 5-50% by mass, preferably 15-45% by mass.

The solvent replacement step is a step of replacing methanol, which is a dispersion solvent of methanol-dispersed silica sol, with the same solvent as the solvent contained in the resin composition. The solvent contained in the resin composition is a solvent that dissolves the polyimide resin, and can be selected from the solvents exemplified above as the solvent used in the production of the polyimide resin, as long as It only needs to be a solvent with a boiling point higher than that of methanol. From the viewpoint of the ease of solvent replacement, a solvent with a boiling point of 100°C or higher is preferred, and from the viewpoint of the ease of preparing the varnish, N,N-dimethylacetamide, N,N -Amine-based solvents such as dimethylformamide, and lactone-based solvents such as GBL and γ-valerolactone. These solvents can be used alone or in combination of two or more. The solvent replacement step is to add the solvent to the methanol dispersed silica sol or to evaporate the methanol while adding the solvent. Solvent replacement can be carried out under vacuum, reduced pressure or normal pressure. It can also be carried out under normal temperature or heating. It can inhibit the agglomeration of silica particles and easily obtain a silica sol with uniformly dispersed silica particles. From a viewpoint, it is preferable to perform it under reduced pressure, for example at 40-80 degreeC. The solid content concentration of the silica sol replaced by the solvent may be, for example, 5-50% by mass, and preferably 15-40% by mass.

The varnish preparation step is to dissolve the polyamide imide resin in a solvent. For the polyamide imide resin dissolved in the solvent, the solvent contained in the resin composition is preferably dissolved. The step of stirring and mixing the silica sol with the same solvent as the solvent of the imine resin and the additives as needed. From the viewpoint of a faster dissolution rate of the resin, it is preferable to mix the solvent and the silica sol, and to mix and dissolve other components as necessary, and then add the resin to dissolve it.

[Optical Film] The present invention includes an optical film formed from the resin composition of the present invention. The optical film is formed of the above-mentioned resin composition. Therefore, even if it contains nano-sized silicon dioxide particles, the reflectance of bluish light on the surface of the film is reduced. As a result, the bluishness of reflected light can be reduced. . Therefore, when the optical film of the present invention is applied to a display device, good visibility can be obtained.

The thickness of the optical film of the present invention is appropriately adjusted according to the application, and is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 30 μm or more, and preferably 100 μm or less, more preferably 80 μm or less, It is more preferably 65 μm or less, and particularly preferably 55 μm or less. The thickness of an optical film can be measured with a film thickness meter etc., for example, can measure by the method described in an Example.

With regard to the optical film of the present invention, bluish light, for example, light near 400 nm, has a low reflectivity to the film surface. The reflectance (SCI) of the optical film for light with a wavelength of 400 nm is preferably 8.3 or less, more preferably 8.0 or less, still more preferably 7.5 or less, still more preferably 7.0 or less, and particularly preferably 6.5 or less. The lower limit of the reflectance (SCI) is usually above 5.0. Reflectance (SCI) means the reflectance of the light reflected by the optical film obtained by the SCI (Specular Component Include) method. The reflectance (SCI) can be measured using a spectrophotometer, for example, by the method described in the examples.

In the optical film of the present invention, the visual transmittance at a thickness of 50 μm is preferably 80% or more, more preferably 85% or more, still more preferably 88% or more, and usually 100% or less. If the visual transmittance is higher than the above lower limit, the transparency becomes good. For example, when used in the front panel of a display device, it can contribute to higher visibility. Furthermore, the visual transmittance can be measured using a spectrophotometer, for example, by the method described in the examples.

The haze of the optical film of the present invention is preferably 3.0% or less, more preferably 2.0% or less, still more preferably 1.0% or less, still more preferably 0.5% or less, particularly preferably 0.3% or less, and usually 0.01% the above. If the haze of the high-visibility optical film is below the above upper limit, the transparency becomes good. For example, when it is used in the front panel of a display device, it can contribute to higher visibility. In addition, the haze can be measured using a haze meter in accordance with JIS K 7136:2000, for example.

The yellowness (YI) of the optical film of the present invention is preferably 8 or less, more preferably 5 or less, still more preferably 3 or less, particularly preferably 2 or less, and is usually -5 or more, preferably -2 or more. If the yellowness of the optical film is less than the above upper limit, the transparency becomes good. For example, when it is used in the front panel of a display device, it can contribute to higher visibility. Furthermore, the degree of yellowness (YI) can be obtained by measuring the transmittance of light from 300 to 800 nm using an ultraviolet-visible-near-infrared spectrophotometer in accordance with JIS K 7373: 2006 to obtain 3 stimulus values (X, Y, Z), It is calculated based on the formula YI=100×(1.2769X-1.0592Z)/Y. In this specification, the so-called optical characteristics refer to, for example, characteristics that can be evaluated optically including total light transmittance, yellowness (YI), haze, and reflectance (SCI). The so-called "improved optical characteristics", for example, means Increased total light transmittance, decreased yellowness, decreased haze, decreased reflectance (SCI), etc.

The use of the optical film of the present invention is not particularly limited, and can be used in various applications. The optical film of the present invention may be a single layer or a laminate as described above, and the optical film of the present invention may be used directly, and it may also be used as a laminate with other films. Furthermore, when the optical film is a laminate, it is called an optical film including all the layers laminated on one side or both sides of the optical film.

When the optical film of the present invention is a laminate, it is preferable to have one or more functional layers on at least one surface of the optical film. As the functional layer, for example, an ultraviolet absorbing layer, a hard coat layer, an undercoat layer, a gas barrier layer, an adhesion layer, a hue adjustment layer, a refractive index adjustment layer, etc. may be mentioned. The functional layer can be used alone or in combination of two or more.

The ultraviolet absorbing layer is a layer that has the function of absorbing ultraviolet rays, for example, it is composed of a main material selected from ultraviolet curable transparent resin, electron beam curable transparent resin, and thermosetting transparent resin, and dispersed in the main material It is composed of UV absorbers in

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

The adhesive layer may be a layer which is called a pressure sensitive adhesive (PSA, Pressure Sensitive Adhesive) that is adhered to an object by pressing. Pressure-sensitive adhesives can be used as "substances that are adhesive at room temperature and adhere to the bonded material under lighter pressure" (JIS K 6800), and can also be used as "incorporating specific ingredients in It protects the film (microcapsules) and maintains stability until the film is destroyed by an appropriate method (pressure, heat, etc.)" (JIS K 6800) capsule type adhesive.

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

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

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

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

[Method of manufacturing optical film] The optical film of the present invention is not particularly limited. For example, it can be manufactured by a method including the following steps: (a) The step of applying the above-mentioned resin composition to the support material to form a coating film (coating step), and (b) The step of drying the applied liquid (coating film) to form an optical film (film forming step).

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

In the film forming step, the coating film is dried and peeled from the support material to form an optical film. The drying temperature of the coating film can usually be carried out at a temperature of 50 to 300°C. In a preferred embodiment of the present invention, the coating film is dried at 50 to 150°C (also referred to as the first drying), and after the support material is peeled off, the second drying is performed at 200 to 250°C. The time for the first drying and the second drying is, for example, 5 to 180 minutes, and preferably 30 to 120 minutes. The drying of the coating film can be carried out in an inert atmosphere or under reduced pressure as required.

Examples of support materials include: PET (Polyethylene Terephthalate) film, PEN (Polyethylene Naphthalate, polyethylene naphthalate) film, other polyimide resin films, etc. . Among them, from the viewpoint of excellent heat resistance, a PET film, a PEN film, etc. are preferred, and from the viewpoint of adhesion to the optical film and cost, a PET film is more preferred.

In a suitable embodiment of the present invention, as described above, when manufacturing an optical film from the resin composition, heating to a high temperature, preferably about 200°C or more, is preferable to dry the coating film in the atmosphere. The obtained optical film contains silicon dioxide particles which are removed from the solvent in the resin composition, and the silicon dioxide particles in the resin composition satisfy the relationship of formula (4) to formula (6) : L*≧80 (4) -3.0≦a*≦3.0 (5) 7.5≦b*≦20 (6) [In formulas (4)～(6), L*, a* and b* respectively represent the color coordinates L*, a* and b* in the L*a*b* color system] The way to change. That is, the optical film of the present invention includes silicon dioxide particles having a primary particle size of 5-50 μm and satisfying the relationship of formulas (4) to (6).

The L*, a* and b* in formulas (4)～(6) are in addition to the operation of heating the silica sol with the silica particles dispersed in the atmosphere at a temperature of 200°C for 1 hour, and are combined with For those corresponding to L*, a* and b* in formula (1) to formula (3), the preferred range is also the same range. In addition, the polyamide resin contained in the optical film is the same as the polyamide resin contained in the resin composition.

[Flexible Image Display Device] The optical film of the present invention can be suitably used as a flexible display device. The optical film of the present invention is preferably used as a front panel in a flexible image display device, and the front panel is sometimes called a window film. The flexible image display device includes a laminate for a flexible image display device and an organic EL display panel. For the organic EL display panel, the laminate for a flexible image display device is arranged on the viewing side, and the laminate is flexible. The way of folding is composed. As a laminated body for a flexible image display device, it may further contain a polarizing plate, preferably a circular polarizing plate, and a touch sensor. The order of these layers is arbitrary, and it is preferable that the layers are sequentially stacked from the viewing side Window film, polarizing plate, touch sensor, or window film, touch sensor, polarizing plate. If there is a polarizing plate on the viewing side of the touch sensor, the pattern of the touch sensor is not easy to see, and the visibility of the displayed image becomes better, which is better. Each member can be laminated using adhesives, adhesives, etc. In addition, it may be provided with a light-shielding pattern formed on at least one surface of any one of the above-mentioned window film, polarizer, and touch sensor.

[Polarizer] As described above, the flexible display device preferably includes a polarizing plate, especially a circular polarizing plate. The circular polarizing plate is a functional layer that has a function of transmitting only right or left circularly polarized light components by laminating a λ/4 phase difference plate on a linear polarizing plate. For example, it is used to block the conversion of external light into right-handed circularly polarized light, which is reflected by the organic EL panel to become left-handed circularly polarized outer light, and only transmits the luminous components of the organic EL, thereby suppressing the influence of reflected light and making the image Easy to see. In order to achieve the circular polarization function, the absorption axis of the linear polarizer and the late axis of the λ/4 retardation plate need to be 45° in theory, and 45±10° in practice. The linear polarizing plate and the λ/4 retardation plate do not necessarily need to be laminated adjacently, as long as the relationship between the absorption axis and the slow phase axis satisfies the above range. It is preferable to achieve complete circular polarization at the full wavelength, but this is not necessarily required in practice. Therefore, the circular polarization plate in the present invention also includes an elliptical polarization plate. It is also preferable to laminate a λ/4 retardation film on the visibility side of the linear polarizing plate to make the emitted light circularly polarized, thereby improving the visibility when wearing polarized sunglasses.

The linear polarizer is a functional layer that has the function of passing light that vibrates in the direction of the transmission axis, but blocking the polarization of the vibration component perpendicular to it. The above-mentioned linear polarizing plate may be a structure having a linear polarizing element alone, or a structure having a linear polarizing element and a protective film attached to at least one surface thereof. The thickness of the linear polarizing plate may be 200 μm or less, preferably 0.5-100 μm. If the thickness of the linear polarizer is within the above range, there is a tendency that the flexibility of the linear polarizer is not easily reduced.

The linear polarizing element described above may be a film-type polarizing element manufactured by dyeing and stretching a polyvinyl alcohol (hereinafter, abbreviated as PVA) film. By adsorbing dichroic pigments such as iodine to the PVA-based film aligned by stretching, or by stretching while adsorbing on PVA, the dichroic pigments are aligned to exhibit polarization performance. In the manufacture of the above-mentioned film-type polarizing element, it can also have steps such as swelling, cross-linking with boric acid, washing with aqueous solution, and drying. The stretching or dyeing step may be performed on a PVA-based film alone, or may be performed in a state of being laminated with other films such as polyethylene terephthalate. The thickness of the PVA-based film used is preferably 10-100 μm, and the above-mentioned stretching ratio is preferably 2-10 times. Furthermore, as another example of the above-mentioned polarizing element, a liquid crystal coating type polarizing element formed by applying a liquid crystal polarizing composition can be cited. The liquid crystal polarizing composition may include a liquid crystal compound and a dichroic dye compound. The above-mentioned liquid crystalline compound only needs to have the property of displaying a liquid crystal state, and if it has an alignment state of the same order as the smectic sequence, it can exhibit higher polarization performance, so it is preferable. Furthermore, it is preferable that the liquid crystal compound has a polymerizable functional group. The dichroic dye compound is a dye that is aligned together with the liquid crystal compound to exhibit dichroism, and may have a polymerizable functional group, and the dichroic dye itself may have liquid crystallinity. Any of the compounds contained in the liquid crystal polarizing composition has a polymerizable functional group. The above-mentioned liquid crystal polarizing composition may further include a starter, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like. The above-mentioned liquid crystal polarizing layer is manufactured by coating a liquid crystal polarizing composition on an alignment film to form a liquid crystal polarizing layer. The liquid crystal polarizing layer can be formed thinner than the thickness of the film-type polarizing element, and its thickness is preferably 0.5-10 μm, more preferably 1-5 μm.

The above-mentioned alignment film is produced by, for example, coating an alignment film forming composition on a substrate, and imparting alignment properties by rubbing, polarized light irradiation, or the like. The aforementioned alignment film forming composition includes an alignment agent, and may further include a solvent, a crosslinking agent, a starter, a dispersant, a leveling agent, a silane coupling agent, and the like. Examples of the alignment agent include polyvinyl alcohols, polyacrylates, polyamides, and polyimines. In the case of using an alignment agent that imparts alignment properties by polarized light irradiation, it is preferable to use an alignment agent containing a cinnamate group. The weight average molecular weight of the polymer used as the above-mentioned alignment agent is, for example, about 10,000 to 1,000,000. The thickness of the alignment film is preferably 5 to 10,000 nm, and more preferably 10 to 500 nm from the viewpoint of sufficiently exhibiting the alignment restriction force. The above-mentioned liquid crystal polarizing layer may be peeled from the base material and transferred and laminated, or the above-mentioned base material may be directly laminated. The above-mentioned base material is also preferably used as a protective film, phase difference plate, or window film.

As the above-mentioned protective film, it is sufficient as long as it is a transparent polymer film. Specifically, as the polymer film to be used, examples include: polyethylene, polypropylene, polymethylpentene, norbornene or cycloolefin (Modified) celluloses such as cycloolefin derivatives such as cyclic olefin derivatives, diacetyl cellulose, triacetyl cellulose, propylene cellulose, etc. (modified) cellulose, methyl methacrylate (co- ) Acrylics such as polymers, polystyrenes such as styrene (co)polymers, acrylonitrile-butadiene-styrene copolymers, acrylonitrile-styrene copolymers, ethylene-vinyl acetate copolymers , Polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, polyarylate and other polyesters , Nylon and other polyamides, polyimides, polyimides, polyetherimines, polyethers, polyvinyl alcohols, polyvinyl acetals, poly Films such as urethanes and epoxy resins are preferably polyamide, polyimidimide, polyimide, polyester, and olefin in terms of excellent transparency and heat resistance. , Acrylic or cellulose film. These polymers can be used alone or in mixture of two or more kinds. These films are used as unstretched, or uniaxially or biaxially stretched films. In addition, it may be a coating type protective film obtained by applying and curing a cationic curing composition such as epoxy resin or a radical curing composition such as acrylate. The protective film may also contain plasticizers, ultraviolet absorbers, infrared absorbers, coloring agents such as pigments or dyes, fluorescent whitening agents, dispersants, heat stabilizers, light stabilizers, antistatic agents, and antistatic agents as needed. Oxidizers, lubricants, solvents, etc. The thickness of the protective film is preferably 200 μm or less, more preferably 1-100 μm. If the thickness of the protective film is within the above range, the flexibility of the film tends not to decrease easily.

The above-mentioned λ/4 retardation plate is a film that gives a λ/4 retardation to a direction perpendicular to the traveling direction of incident light (in-plane direction of the film). The above-mentioned λ/4 retardation plate may be a stretched retardation plate manufactured by stretching a polymer film such as a cellulose-based film, an olefin-based film, or a polycarbonate-based film. The above-mentioned λ/4 retardation plate may also contain retardation adjusters, plasticizers, ultraviolet absorbers, infrared absorbers, coloring agents such as pigments or dyes, fluorescent brighteners, dispersants, heat stabilizers, Light stabilizers, antistatic agents, antioxidants, lubricants, solvents, etc. The thickness of the extended phase difference plate is preferably 200 μm or less, more preferably 1-100 μm. If the thickness of the extended phase difference plate is within the above range, the flexibility of the extended phase difference plate tends to be less likely to decrease. Furthermore, as another example of the aforementioned λ/4 retardation plate, a liquid crystal coating type retardation plate formed by applying a liquid crystal composition can be cited. The above-mentioned liquid crystal composition contains a liquid crystal compound that exhibits a liquid crystal state such as nematic, cholesteric, smectic, and the like. The liquid crystal compound has a polymerizable functional group. The above-mentioned liquid crystal composition may further include a starter, a solvent, a dispersant, a leveling agent, a stabilizer, a surfactant, a crosslinking agent, a silane coupling agent, and the like. The above-mentioned liquid crystal coating type retardation plate can be manufactured by the following method similarly to the above-mentioned liquid crystal polarizing layer: a liquid crystal composition is coated on a substrate, and it is hardened to form a liquid crystal retardation layer. The liquid crystal coating type retardation plate can be formed thinner than the extension type retardation plate. The thickness of the liquid crystal polarizing layer is preferably 0.5-10 μm, more preferably 1-5 μm. The above-mentioned liquid crystal coating type retardation plate may be peeled from the base material and transferred and laminated, or the base material may be directly laminated. The above-mentioned base material is also preferably used as a protective film, phase difference plate, or window film.

Generally, the shorter the wavelength, the greater the birefringence, and the longer the wavelength, the smaller the birefringence. In this case, the phase difference of λ/4 cannot be achieved in the entire visible light region. Therefore, the phase difference of λ/4 relative to the vicinity of 560 nm, which has a higher visibility, is preferably 100 to 180 nm. , It is better to design for the 130～150 nm method. The reverse dispersion λ/4 retardation plate using a material having birefringence wavelength dispersion characteristics opposite to the usual one is better in terms of improving visibility. As such a material, for example, an extension type retardation plate can be used for those described in Japanese Patent Laid-Open No. 2007-232873 etc., and a liquid crystal coating type retardation plate can be used for Japanese Patent Laid-Open No. 2010-30979 etc. Recorded. In addition, as another method, a technique of obtaining a wide-band λ/4 retardation plate by combining with a λ/2 retardation plate is also known (for example, Japanese Patent Laid-Open No. 10-90521, etc.). The λ/2 retardation plate is also manufactured by the same material method as the λ/4 retardation plate. The combination of the extension type retardation plate and the liquid crystal coating type retardation plate is arbitrary, and any one of them can be thinned by using a liquid crystal coating type retardation plate. Among the above-mentioned circularly polarizing plates, in order to improve the visibility in the oblique direction, a method of laminating positive C plates is known (for example, Japanese Patent Laid-Open No. 2014-224837 etc.). The positive C plate can be a liquid crystal coating type retardation plate or an extended type retardation plate. The retardation in the thickness direction of the retardation plate is preferably -200 to -20 nm, more preferably -140 to -40 nm.

[Touch Sensor] As mentioned above, the flexible display device preferably has a touch sensor. The touch sensor can be used as an input mechanism. As the touch sensor, various methods such as a resistive film method, a surface elastic wave method, an infrared method, an electromagnetic induction method, and an electrostatic capacitance method can be cited, and an electrostatic capacitance method is preferable. The capacitive touch sensor is divided into an active area and an inactive area located at the outline of the active area. The active area is the area corresponding to the area on the display panel (display part) that perceives the user's touch, and the inactive area is the area where the picture is not displayed on the display device (non-display part) The corresponding area. The touch sensor may include: a substrate, which has the characteristics of flexibility; a sensing pattern, which is formed on the active area of the substrate; and each sensing line, which is formed on the inactive area of the substrate, for sensing The pattern and the pad are connected to an external driving circuit. As a substrate with flexible characteristics, the same material as the above-mentioned polymer film can be used.

The aforementioned sensing pattern may include a first pattern formed in the first direction and a second pattern formed in the second direction. The first pattern and the second pattern are arranged in mutually different directions. The first pattern and the second pattern are formed on the same layer. In order to sense the touch location, each pattern must be electrically connected. The first pattern is a form in which a plurality of unit patterns are connected to each other through a joint, and the second pattern is a structure in which a plurality of unit patterns are separated from each other into an island shape. Therefore, in order to electrically connect the second pattern, another bridge electrode is required. The electrode for connecting the second pattern can be a well-known transparent electrode. Examples of materials for the transparent electrode include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), indium gallium zinc oxide (IGZO) ), cadmium tin oxide (CTO), PEDOT (poly(3,4-ethylenedioxythiophene), poly(3,4-ethylenedioxythiophene)), carbon nanotube (CNT), graphene and metal wire, etc. ITO is preferably mentioned. These can be used individually or in mixture of 2 or more types. The metal used in the metal wire is not particularly limited, and examples thereof include silver, gold, aluminum, copper, iron, nickel, titanium, selenium, and chromium. These can be used alone or in combination of two or more. The bridging electrode can be formed on the upper part of the insulating layer via the insulating edge layer on the upper part of the sensing pattern, and the bridging electrode can be formed on the substrate, and the insulating layer and the sensing pattern can be formed thereon. The bridging electrode may be formed of the same material as the sensing pattern, or may be formed of molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium, or an alloy of two or more of these. The first pattern and the second pattern must be electrically insulated, so an insulating layer is formed between the sensing pattern and the bridge electrode. The insulating layer may be formed only between the joints of the first pattern and the bridging electrodes, or may be formed as a layer covering the entire sensing pattern. In the case of covering the entire sensing pattern layer, the bridge circuit can be connected to the second pattern through the contact hole formed in the polar insulating layer.

Regarding the above-mentioned touch sensor, it is used to appropriately compensate for the difference in transmittance between the pattern area where the sensing pattern is formed and the non-pattern area where the sensing pattern is not formed, specifically, the refractive index in these areas The method of the difference in light transmittance induced by the difference may further include an optical adjustment layer between the substrate and the electrode. The optical adjustment layer may include an inorganic insulating material or an organic insulating material. The optical adjustment layer can be formed by coating a photocuring composition containing a photocuring organic binder and a solvent on a substrate. The above-mentioned photocurable composition may further contain inorganic particles. The above-mentioned inorganic particles can increase the refractive index of the optical adjustment layer. The above-mentioned photocurable organic adhesive may be within a range that does not impair the effects of the present invention, for example, a copolymer containing monomers such as acrylate monomers, styrene monomers, and carboxylic acid monomers. The photocurable organic adhesive may be, for example, a copolymer containing repeating units that are different from each other, such as epoxy-containing repeating units, acrylate repeating units, and carboxylic acid repeating units. Examples of the above-mentioned inorganic particles include zirconium oxide particles, titanium oxide particles, and aluminum oxide particles. The aforementioned photocurable composition may further contain various additives such as a photopolymerization initiator, a polymerizable monomer, and a curing auxiliary agent.

[Next layer] The layers (window film, circular polarizing plate, touch sensor) and the film members (linear polarizing plate, λ/4 phase difference plate, etc.) constituting each layer that form the laminated body for the flexible image display device can be used for bonding Agent for joining. As the adhesive, water-based adhesives, organic solvent-based, solvent-free adhesives, solid adhesives, solvent-volatile adhesives, moisture-curing adhesives, heat-curing adhesives, anaerobic curing type, active Commonly used adhesives such as energy ray hardening type adhesive, hardener mixed type adhesive, hot-melt type adhesive, pressure sensitive type adhesive (adhesive), rewet type adhesive, etc., preferably water-based solvent volatilization Type adhesive, active energy ray hardening type adhesive, adhesive. The thickness of the adhesive layer can be appropriately adjusted according to the required adhesive force, etc., preferably 0.01-500 μm, more preferably 0.1-300 μm. The subsequent layer may have a plurality of layers in the above-mentioned flexible image display device laminate, and the thickness or type of each may be the same or different.

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

The active energy ray curable adhesive can be formed by curing an active energy ray curable composition containing a reactive material that forms an adhesive layer by irradiating active energy rays. The active energy ray curable composition may contain at least one polymer of the same radically polymerizable compound and cationically polymerizable compound as those contained in the hard coat composition. The radical polymerizable compound can be the same as the radical polymerizable compound in the hard coat composition. The above-mentioned cationically polymerizable compound can be the same as the cationically polymerizable compound in the hard coat composition. The cationic polymerizable compound used in the active energy ray curing composition is preferably an epoxy compound. In order to reduce the viscosity of the adhesive composition, it is also preferable to include a monofunctional compound as a reactive diluent.

In order to reduce the viscosity, the active energy ray composition may contain a monofunctional compound. Examples of the monofunctional compound include: an acrylate-based monomer having one (meth)acryloyl group in one molecule, or a compound having one epoxy group or oxetanyl group in one molecule, for example ( Glycidyl meth)acrylate and the like. The active energy ray composition may further include a polymerization initiator. Examples of the polymerization initiator include radical polymerization initiators, cationic polymerization initiators, radical and cationic polymerization initiators, and the like, and these can be appropriately selected and used. These polymerization initiators are decomposed by at least one of active energy ray irradiation and heating to generate free radicals or cations for radical polymerization and cationic polymerization. In the description of the hard coating composition, an initiator that can start at least either radical polymerization or cationic polymerization by active energy ray irradiation can be used. The active energy ray curable composition may further include an ion scavenger, an antioxidant, a chain transfer agent, an adhesion imparting agent, a thermoplastic resin, a filler, a fluid viscosity adjuster, a plasticizer, a defoamer solvent, an additive, and a solvent. In the case of using the active energy ray hardening adhesive to bond two adhesive layers, the active energy ray hardening composition can be applied to either or both of the adhesive layers, Bonding is performed, and either one of the adhered layers or both of the adhered layers is irradiated with active energy rays to harden them for bonding. In the case of using the active energy ray-curable adhesive, the thickness of the adhesive layer is preferably 0.01-20 μm, more preferably 0.1-10 μm. When the above-mentioned active energy ray-curable adhesive is used for the formation of multiple adhesive layers, the thickness or type of each layer may be the same or different.

As the above-mentioned adhesive, any one of acrylic adhesives, urethane adhesives, rubber adhesives, silicone adhesives, etc. may be classified according to the main agent polymer. In the adhesive, in addition to the main agent polymer, crosslinking agents, silane compounds, ionic compounds, crosslinking catalysts, antioxidants, adhesion imparting agents, plasticizers, dyes, pigments, inorganic fillers, etc. can also be blended . Each component constituting the adhesive is dissolved and dispersed in a solvent to obtain an adhesive composition, and the adhesive composition is coated on a substrate and dried to form an adhesive layer bonding layer. The adhesive layer can be formed directly, or the one formed on the substrate can be transferred by transfer. In order to cover the adhesive surface before bonding, it is also preferable to use a release film. In the case of using the active energy ray-curable adhesive, the thickness of the adhesive layer is preferably 0.1 to 500 μm, more preferably 1 to 300 μm. When the above-mentioned adhesive is used for multiple layers, the thickness or type of each layer may be the same or different.

[Shading Pattern] The aforementioned light-shielding pattern can be applied as at least a part of the frame or housing of the aforementioned flexible image display device. Because the wiring arranged at the edge of the flexible image display device is shielded by the light-shielding pattern and is not easily visible, the visibility of the image is improved. The aforementioned light-shielding pattern may be in the form of a single layer or a multiple layer. The color of the shading pattern is not particularly limited, and can be a variety of colors such as black, white, and metallic. The light-shielding pattern can be formed by using pigment colors for realization, and polymers such as acrylic resins, ester resins, epoxy resins, polyurethanes, and silicones. These can also be used alone or in a mixture of two or more. The above-mentioned light-shielding pattern can be formed by various methods such as printing, offset printing, and inkjet. The thickness of the light-shielding pattern is preferably 1-100 μm, more preferably 2-50 μm. Moreover, it is also preferable to give a shape such as an inclination to the thickness direction of the light shielding pattern. [Example]

Hereinafter, the present invention will be explained more specifically based on examples and comparative examples, but the present invention is not limited to the following examples. The "%" and "parts" in the examples refer to mass% and mass parts unless otherwise specified. First, the measurement and evaluation methods will be described.

＜Thickness of optical film＞ ABS (Acrylonitrile-Butadiene-Styrene, acrylonitrile-butadiene-styrene) digital scale (manufactured by Mitutoyo Co., Ltd., "ID-C112BS") was used to measure the optical films obtained in the examples and comparative examples The thickness of the optical film.

＜Reflectance (SCI) measurement＞ The optical films obtained in the examples and comparative examples were cut into a size of 50 mm×50 mm, and the samples made by sticking to black PET (manufactured by Bachuan Paper Co., Ltd., "KUKKIRI MIERU") were measured by spectroscopy. A color meter (manufactured by Konica Minolta Co., Ltd., "CM-3700A"), measures the reflectance (SCI) to 400 nm light. Reflectance (SCI) means the reflectance of the light reflected by the optical film (sample) obtained by the SCI (Specular Component Include) method. The measurement diameter system is set to MAV: diameter 8 mm, the measurement conditions are set to di: 8°, de: 8° (diffuse illumination, 8° direction light reception), the measurement field of view is set to 2°, the light source uses D65 light source, UV( Ultra Violet (UV) conditions are set to 100% Full. Here, the so-called hue refers to a* and b* in the CIE1976L*a*b* color space.

：30 mm<Chromaticity measurement> (1) Pretreatment method Measure 6.0 g of the silica sol of the Examples and Comparative Examples and place them in an aluminum cup. Use a dryer (manufactured by Yamato Scientific Co., Ltd., DKN-302) under the atmosphere , Heat treatment at 200°C for 1 hour, and measure the obtained powder as follows. Furthermore, in the color measurement, in Examples 1 and 2, methanol-dispersed silica sol was used as the silica sol, and in Comparative Example 1, the water-dispersed silica sol was replaced with GBL. The obtained GBL dispersed silica sol is used as the silica sol. (2) Measuring method device: Color and color difference meter CR-5 manufactured by Konica Minolta Observation condition: 2° field of view (CIE1931) Observation light source: C Color system: L*a*b* color space (color coordinate) Color difference formula: ΔE ^* ab (CIE1976) color difference index: no measurement type: petri dish measurement measurement diameter

: 30 mm

<Measurement of visual transmittance (Y: D65)> The optical transmittance (Y: D65) of the optical films obtained in the examples and comparative examples was obtained by cutting the optical films obtained in the examples and comparative examples into a size of 50 mm×50 mm, using a spectrophotometer ( Konica Minolta Co., Ltd., "CM-3700A"), to measure the visual transmittance (Y) of the film. The measurement diameter at the time of measurement is set to LAV: the diameter is 25.4 mm, and the measurement field of view is set to 2°. In addition, a D65 light source was used as the measurement light source, and the UV condition was set to 100% Full. Here, the so-called hue means a* and b* in the CIE1976L*a*b* color space.

＜Measurement of weight average molecular weight (Mw)＞ Gel Permeation Chromatography (GPC) determination (1) Pretreatment method DMF (Dimethyl Formamide) dissolving solution (10 mM lithium bromide solution) was added to the polyamide imide resin obtained in the examples and comparative examples at a concentration of 2 mg/mL. It was heated while stirring at 80°C for 30 minutes, and after cooling, it was filtered with a 0.45 μm membrane filter, and the obtained was used as a measurement solution. (2) Measurement conditions Column: TSKgel SuperAWM-H×2＋SuperAW2500×1 (6.0 mm I.D.×150 mm×3) (all manufactured by Tosoh Co., Ltd.) Eluent: DMF (add 10 mM lithium bromide) Flow rate: 1.0 mL/min Detector: RI (Refractive Index) detector Column temperature: 40℃ Injection volume: 100 μL Molecular weight standard: standard polystyrene

[Example 1] (Preparation of Silica Sol) Add 517.2 parts of methanol-dispersed silica sol ("MA-ST-M" manufactured by Nissan Chemical Industry Co., Ltd., with a primary particle size of 20-25 nm and a solid content of silica particles of 40.6%) and GBL490 to the flask. 9 parts, using a vacuum evaporator to evaporate methanol at 400 hPa for 1 hour under a hot water bath at 45°C, and at 250 hPa for 1 hour. Furthermore, the temperature was raised to 70°C at 250 hPa and heated for 30 minutes to obtain a γ-butyrolactone dispersed silica sol (sometimes referred to as GBL dispersed silica sol). The solid content of the obtained GBL dispersed silica sol was 29.8%.

(Preparation of polyamide imide resin) Under a nitrogen atmosphere, add 446.1 parts of N,N-dimethylacetamide (DMAc) to a reaction vessel equipped with stirring wings, and add 2,2'-bis(trifluoromethyl) while stirring at room temperature -24.7 parts of 4,4'-diaminobiphenyl (TFMB) and dissolve TFMB in DMAc while stirring at room temperature. Next, 7.5 parts of 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA) was added, and it was stirred and reacted at room temperature. Then, 2.5 parts of 4,4'-oxybis(benzyl chloride) (OBBC) and 14.9 parts of terephthalate chloride (TPC) were added, and it stirred at room temperature for 1 hour. Then, 4.4 parts of 4-picoline and 7.2 parts of acetic anhydride were added, and after stirring at room temperature for 30 minutes, it heated up to 70 degreeC, and stirred for 3 hours further, and obtained the reaction liquid. The obtained reaction liquid was cooled to room temperature, 915.9 parts of methanol and 490.2 parts of water were added, and the deposited precipitate was recovered by filtration and washed with methanol. Next, the precipitate was dried under reduced pressure at 75° C. to obtain a polyimide resin. The weight average molecular weight of the obtained polyimide resin was 420,000.

(Manufacturing of Optical Film) The GBL dispersed silica sol is added to GBL and mixed thoroughly to dissolve the obtained polyimide resin, thereby obtaining a polyimide/silica particle mixed varnish. The mass ratio of polyamide imide resin to silica particles is 70:30. In addition, it was prepared so that the concentration of polyimide/silica dioxide (the total mass of resin and silica particles relative to the mass of varnish) was 10% by mass. After filtering the obtained mixed varnish with a 10 μm mesh filter, the thickness of the independent film becomes 55 μm, and then apply an applicator to the polyester substrate (manufactured by TOYOBO Co., Ltd., trade name "A4100 ") on the smooth surface, dry at 50°C for 30 minutes, and then at 140°C for 15 minutes, and peel off the polyester substrate to obtain an independent film. The independent film was fixed to a gold frame and dried at 200°C to obtain an optical film with a thickness of 50 μm.

[Example 2] Use Nissan Chemical Industry Co., Ltd. product ("Methanol silica sol", primary particle size 10-15 nm) as methanol-dispersed silica sol, and set the mass ratio of polyimide resin to silica particles as 60:40, except that an optical film was obtained in the same manner as in Example 1.

[Comparative Example 1] Using water-dispersed silica sol (product of Nissan Chemical Industry Co., Ltd., "ST-O", primary particle size 10-15 nm) instead of methanol-dispersed silica sol, the same procedure as in Example 2 was used except Obtain an optical film.

Compare the L*a*b*, the primary particle size of the silica particles, and the mass of the silica particles obtained in the chromaticity measurement of the silica sol in Examples 1, 2 and Comparative Example 1 to the optical film The mass (%), the total light transmittance of the optical films in Examples 1, 2 and Comparative Example 1 and the reflectance (SCI) for light at 400 nm are shown in Table 1.

[Table 1] Silicon dioxide Visual transmittance (%) Reflectance (SCI) L* a* b* Primary particle size (nm) quality(%) Example 1 89.5 -0.56 10.35 20-25 30 90.1 6.11 Example 2 89.0 -1.69 7.98 10-15 40 89.2 8.28 Comparative example 1 89.5 -1.84 7.20 10-15 40 89.1 8.41

As shown in Table 1, it was confirmed that the optical films obtained in Examples 1 and 2 had lower reflectance (SCI) and less bluishness of reflected light than the optical films obtained in Comparative Example 1. In addition, it can be seen that the reflectance (SCI) of the optical film of Example 1 containing the silica particles with higher b* in the colorimetric measurement of the silica sol is significantly lower, and the bluishness of the reflected light is significantly reduced.

Claims (11)

A resin composition comprising a polyamideimide resin and silicon dioxide particles with a primary particle diameter of 5-50 nm, and the silicon dioxide particles satisfy the relationship of formula (1) to formula (3): L*≧80 (1) -3.0≦a*≦3.0 (2) 7.5≦b*≦20 (3) [In formulas (1) to (3), L*, a*, and b* respectively represent the second precipitation when the silica sol dispersed with the silica particles is heated in the atmosphere at a temperature of 200°C for 1 hour The color coordinates L*, a* and b* of silica particles in the L*a*b* color system]. The resin composition of claim 1, wherein the polyimide resin contains: a structural unit derived from a tetracarboxylic acid compound containing a structural unit derived from an aromatic tetracarboxylic acid compound, and a structural unit derived from an aromatic dicarboxylic acid The structural unit of the acid compound is derived from the dicarboxylic acid compound, and the total molar amount of the structural unit derived from the aromatic tetracarboxylic acid compound and the structural unit derived from the aromatic dicarboxylic acid compound is relative to the source The total molar amount of the structural unit from the tetracarboxylic acid compound and the structural unit derived from the dicarboxylic acid compound is 10 molar% or more. The resin composition of claim 1 or 2, wherein the polyimide resin contains a halogen atom. The resin composition according to any one of claims 1 to 3, wherein the weight average molecular weight of the polyamide resin is 150,000 or more in terms of polystyrene. The resin composition according to any one of claims 1 to 4, wherein the silicon dioxide particles are surface-modified silicon dioxide particles. The resin composition according to any one of claims 1 to 5, wherein the content of the silicon dioxide particles is 0.1-60 parts by mass relative to 100 parts by mass of the solid content of the resin composition. The resin composition according to any one of claims 1 to 6, which further includes a solvent. An optical film formed of the resin composition according to any one of claims 1 to 7. For example, the optical film of claim 8 has a thickness of 10-100 μm. The resin composition according to any one of claims 1 to 7, wherein the silica particles are formed by dispersing silica sol in methanol. The resin composition of claim 7, wherein the silica particles are formed of methanol dispersed silica sol replaced by the same solvent as the above-mentioned solvent.