KR20180094840A - Film, resin composition and method for producing polyamide-imide resin - Google Patents

Abstract

It is an object of the present invention to provide a film having a high surface hardness, including a polyamide-imide resin having a high imidization rate, which can be suitably used as a front plate of, for example, a flexible display or the like.
The present invention relates to a resin composition containing at least a structural unit derived from a diamine, a structural unit derived from a dicarboxylic acid, and a structural unit derived from a tetracarboxylic dianhydride and having an imidization rate of 95% or more ≪ RTI ID = 0.0 > A < / RTI >

Description

Film, resin composition and method for producing polyamide-imide resin

The present invention relates to a film comprising a polyamide-imide resin, a resin composition comprising the polyamide-imide resin, and a process for producing the polyamide-imide resin.

2. Description of the Related Art Currently, image display devices such as liquid crystal display devices and organic EL display devices are widely used not only for television but also for various purposes such as mobile phones and smart watches. [0003] As these applications are expanded, an image display device (flexible display) having a flexible characteristic is required. The image display device is composed of constituent members such as a polarizing plate, a retardation plate, and a front plate in addition to a display element such as a liquid crystal display element or an organic EL display element. In order to achieve a flexible display, all these components need to have flexibility.

Up to now, glass has been used as a front plate. Glass is high in transparency and can exhibit high hardness depending on the kind of glass, but is very rigid and fragile, so it is difficult to use it as a front plate material of a flexible display.

Therefore, utilization of a polymer material as a material replacing glass has been studied. Since the front plate made of a polymer material is easy to exhibit flexible characteristics, it can be expected to be used for various purposes. As the resin having flexibility, there can be mentioned various ones, but one of them is polyamideimide resin. The polyamide-imide resin is used for various purposes from the viewpoints of transparency and heat resistance, and various production methods thereof have been studied.

For example, in Patent Document 1, there are disclosed a unit structure derived from TFDB (2,2'-bistrifluoromethyl-4,4'-biphenyldiamine), 6FDA (4,4 '- (hexafluoroisopropyl And a unit structure derived from terephthaloyl chloride (terephthaloyl chloride) (1,4-benzenedicarbonyl chloride)) is copolymerized with a copolymerized polyamideimide film .

Patent Document 2 discloses a copolymerized polyamide film having excellent mechanical properties such as pencil hardness.

Japan Public Patent Specification Table 2015- 521686 Japan Public Patent Specification Table 2014-528490

Conventionally, a film containing a polyamide-imide resin used as a front plate is required to exhibit a high surface hardness of the film with high transparency. However, evaluation results of the surface hardness depend on the film production method and film measurement conditions There were problems such as largely different.

For example, the film described in Patent Document 1 has an average transmittance of at least 89% at a wavelength of 380 to 780 nm, but it is unclear whether the film has a sufficiently high surface hardness. There is also no suggestion of a form suitable for high surface hardness development. Patent Document 2 discloses that the film has a surface pencil hardness of 3H or more. However, when the pencil hardness is evaluated, the results may differ depending on the illuminance condition to be used.

Therefore, an object of the present invention is to provide a film having a high surface hardness, which comprises a polyamide-imide resin having a high imidization rate, which is suitably used as a front plate of a flexible display or the like.

In order to solve the above problems, the inventors of the present invention have extensively studied various properties of the polyamide-imide resin by focusing on the imidization ratio of the polyamide-imide resin and the surface hardness of the resulting film. As a result, it has been found that the use of a polyamide-imide resin satisfying specific requirements can increase the surface hardness of the film, and the present invention has been accomplished.

That is, the present invention includes the following preferred aspects.

[1] A thermoplastic resin composition containing at least a structural unit derived from a diamine, a structural unit derived from a dicarboxylic acid, and a structural unit derived from a tetracarboxylic dianhydride and having an imidization ratio of 95% or more A film comprising a polyamideimide resin (A).

[2] The diamine is represented by the formula (3):

[Chemical Formula 1]

[In the formula (3), X represents a group represented by the formula (3e '):

(2)

Wherein each of R ¹⁰ to R ¹⁷ independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and the hydrogen atom contained in R ¹⁰ to R ¹⁷ , Each independently represents a halogen atom, and * represents a bond).

The film according to the above [1], wherein the film comprises at least one kind of compound represented by the following formula (1).

[3] Dicarboxylic acid is represented by the formula (2):

(3)

(2), Z is a group represented by the formula (2a) or (2b):

[Chemical Formula 4]

Of [formula (2a) and Equation (2b), U 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-, - B ¹ and B ² each independently represent an OH or a halogen atom, or a group represented by the formula: Ar-C (CH ₃ ) ₂ -Ar- or Ar-SO ₂ -Ar- Atom.]

The film according to the above [1] or [2], which comprises at least one kind of compound represented by the following general formula (1).

[4] The tetracarboxylic dianhydride is represented by the formula (4):

[Chemical Formula 5]

[In the formula (4), Y represents a group represented by the formula (4g):

[Chemical Formula 6]

(In the formula (4g), W ¹ represents a single bond, -C (CH ₃ ) ₂ - or C (CF ₃ ) ₂ -, and * represents a bonding bond.

The film according to any one of [1] to [3], wherein the film comprises at least one kind of compound represented by the following formula (1).

[5] The film according to any one of [1] to [4], wherein the polyamideimide resin A contains a fluorine atom.

[6] A film according to any one of [1] to [5], wherein the film has a YI of 3 or less.

[7] A film according to any one of [1] to [6], wherein the film has a pencil hardness of 3B or more as measured according to ASTM D 3363 under an illuminance condition of 4000 lux.

[8] A polymer having a structural unit derived from a diamine, a structural unit derived from a dicarboxylic acid, and a structural unit derived from a tetracarboxylic dianhydride, and having a structural unit derived from a tetracarboxylic dianhydride and having an imidization ratio of 60% An amide imide resin B, and a solvent.

[9] The diamine is represented by the formula (3):

(7)

[In the formula (3), X represents a group represented by the formula (3e '):

[Chemical Formula 8]

Wherein each of R ¹⁰ to R ¹⁷ independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and the hydrogen atom contained in R ¹⁰ to R ¹⁷ , Each independently represents a halogen atom, and * represents a bond.]

Is at least one kind of compound represented by the following formula (1).

[10] Dicarboxylic acid is represented by the formula (2):

[Chemical Formula 9]

[In the formula (2), Z represents the following formula (2a) or (2b):

[Chemical formula 10]

Of [formula (2a) and Equation (2b), U 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-, - B ¹ and B ² each independently represent an OH or a halogen atom, or a group represented by the formula: Ar-C (CH ₃ ) ₂ -Ar- or Ar-SO ₂ -Ar- Atom.]

The resin composition according to the above [8] or [9], wherein the resin composition contains at least one kind of compound represented by the following formula.

[11] The tetracarboxylic acid dianhydride is represented by the formula (4):

(11)

[In the formula (4), Y represents the following formula (4g):

[Chemical Formula 12]

(In the formula (4g), W ¹ represents a single bond, -C (CH ₃ ) ₂ - or C (CF ₃ ) ₂ -, and * represents a bonding bond.

The resin composition according to any one of the above [8] to [10], which comprises at least one kind of compound represented by the following general formula

[12] The resin composition according to any one of the above [8] to [11], wherein the polyamideimide resin B contains a fluorine atom.

[13] A film obtained by drying a coating film of the resin composition according to any one of [8] to [12] above.

(14) A method for producing a polyamideimide resin precursor, comprising the steps of: (1) copolymerizing a diamine, a dicarboxylic acid, and a tetracarboxylic acid dianhydride in a solvent to obtain a polyamideimide resin precursor,

(2) a step of adding a dehydrating agent and a tertiary amine to a solution containing at least a polyamideimide resin precursor and heating at a temperature of 70 to 120 캜

(Ppm) and the heating time in the step (2) is t (minute), the amount of water in the solvent at the time of starting the step (1) , w and t satisfy the following expression:

[Equation 1]

. ≪ / RTI >

[15] The production method according to the above-mentioned [14], wherein the molar amount of the dehydrating agent added in the step (2) is at least twice the molar amount of the tetracarboxylic dianhydride added in the step (1).

According to the present invention, a film having a high surface hardness can be obtained which contains a polyamide-imide resin having a high imidization ratio and is preferably used as a front plate or the like in an image display apparatus or the like.

Hereinafter, embodiments of the present invention will be described in detail. The scope of the present invention is not limited to the embodiments described herein, and various modifications can be made without departing from the spirit of the present invention.

The film of the present invention comprises a polyamideimide resin A having an imidization rate of 95% or more as measured by two-dimensional NMR. If the imidization rate of the polyamide-imide resin A is lower than 95%, the surface hardness of the film containing the polyamide-imide resin can not be sufficiently increased because the polyamide-imide resin A tends to become an excessively flexible primary amide structure . From the viewpoint of the stability of the polyamideimide varnish, the imidization rate of the polyamideimide resin A is preferably 97% or more, more preferably 98% or more, even more preferably 99% or more. The higher the imidization rate is, the better the higher the rate of imidization is, and the upper limit is not particularly limited and may be 100% or less. As a method for adjusting the imidization ratio of the polyamide-imide resin A to the above-mentioned range, there can be mentioned, for example, a method of producing a film by using a polyamide resin composition described later and then imidizing it, And a method of producing a film using a composition comprising the polyamide-imide resin produced by the above-mentioned method.

The imidization ratio of the polyamideimide resin A is preferably set such that the ratio of the number of moles of the imide bond in the polyamideimide resin A to the value of twice the number of moles of the constituent unit derived from the tetracarboxylic dianhydride in the polyamideimide resin A And is measured by two-dimensional NMR in the present specification. Conventionally, the measurement of the imidization ratio of the polyamideimide resin is often performed by using infrared spectroscopy. However, in this method, as described in Japanese Patent Application Laid-Open No. 2004-338160, It is necessary to measure the resin which is sufficiently imidized. However, in order to sufficiently imidize the resin, it is necessary to heat the resin to a high temperature, and a decomposition reaction of the resin may occur at the same time during the heating process, so that there is an error, and the imidization rate can not be accurately measured. The present inventors have studied to measure the imidization ratio of a polyamide-imide resin with high accuracy using two-dimensional NMR. As a result, it has been found that a polyamide-imide resin having a predetermined imidization ratio measured by two- It has been found that a film comprising A achieves high surface hardness. The imidization ratio of the polyamide-imide resin A can be measured using two-dimensional NMR using a predetermined solution obtained by dissolving the film in deuterated dimethyl sulfoxide (DMSO-d6) as a measurement sample. Details of the measurement conditions for two-dimensional NMR are shown in the examples.

The pencil hardness (surface hardness) of the film of the present invention is preferably not less than 3B, more preferably not less than 2B, more preferably not less than B, particularly preferably not less than 3B, as measured according to ASTM D 3363 under a condition of illumination of 4000 lux HB or more, very preferably H or more, and most preferably 2H or more. When the pencil hardness of the film of the present invention is not less than the above lower limit, scratches on the surface of the image display device can be easily suppressed when used as a front plate (window film) of an image display device, Therefore, it is preferable. The upper limit of the pencil hardness of the film of the present invention is not particularly limited. The pencil hardness is measured in accordance with JIS K5600-5-4: 1999. More specifically, the measurement is carried out under a load of 100 g and a scanning speed of 60 mm / min, and the evaluation is carried out under the condition of light intensity of 4000 lux. When evaluating the pencil hardness, the results may differ depending on the used illumination conditions. More specifically, the pencil hardness measured by performing evaluation under the illuminance condition of a lower light amount as compared with the pencil hardness measured by the evaluation under the illuminance condition of the light quantity of 4000 lux is such that the scratch on the film is hard to be seen due to the lower light quantity , There is a high possibility that a higher pencil hardness than that actually obtained. Therefore, the pencil hardness in this specification is a value obtained by evaluating under the condition of light intensity of 4000 lux.

The YI value of the film of the present invention is preferably 3.5 or less, more preferably 3.0 or less, and still more preferably 2.5 or less. When the YI value is not more than the upper limit, the visibility of the film can be further increased. The lower limit of the YI value is not particularly limited, and it is usually 0 or more. The YI value represents the yellow index (YI value) of the film and is measured using a spectrophotometer (ultraviolet visible near infrared spectrophotometer V-670 manufactured by Nippon Bunko K.K.) according to JIS K 7373: 2006 do. Specifically, it is calculated from the three-pole value (X, Y, Z) obtained by measuring the transmittance with respect to light of 300 to 800 nm on the basis of the following expression. For the measurement, for example, a film having a thickness of 50 to 55 mu m can be used. In the film of the present invention, if the YI value is within the above range, the thickness of the film is not particularly limited, but it is preferable that the film is within the above-mentioned range in the thickness range described below.

&Quot; (2) "

The thickness of the film of the present invention is preferably not less than 20 占 퐉, more preferably not less than 30 占 퐉, more preferably not less than 40 占 퐉, from the viewpoint that the pencil hardness also affects the film thickness. The thickness of the film of the present invention is preferably 300 占 퐉 or less, more preferably 200 占 퐉 or less, and even more preferably 100 占 퐉 or less, from the viewpoint of bending resistance. The thickness is measured using a contact type digimatic indicator.

The total light transmittance (Tt) of the film of the present invention is preferably not less than 70%, more preferably not less than 80%, more preferably not less than 85%, particularly preferably not less than 80% as measured according to JIS K 7105: 1981 Is more than 90%. When the total light transmittance is not less than the above lower limit, the visibility of the film of the present invention when assembled into an image display device can be easily increased. The upper limit of the total light transmittance of the film of the present invention is usually 100% or less. The total light transmittance is measured by using a fully automatic Hayes computer HGM-2DP manufactured by Suga Test Instruments Co., Ltd. in accordance with JIS K 7105: 1981, for example. For the measurement, for example, a film having a thickness of 50 to 55 mu m can be used. In the film of the present invention, the thickness of the film is not particularly limited as long as the total light transmittance is in the above range, but it is preferable that the film is within the above range within the above-mentioned thickness range.

The modulus of elasticity of the film of the present invention is preferably 5.9 ㎬ or less, more preferably 5.5 ㎬ or less, further preferably 5.2 ㎬ or less, particularly preferably 5.0 ㎬ or less, and most preferably, 4.5 ㎬ or less. When the elastic modulus is less than the above upper limit, it is easy to suppress the damage of other members by the film when the flexible display is bent. The lower limit of the modulus of elasticity of the film of the present invention is not particularly limited, but is usually 2.0 ㎬ or more. The elastic modulus can be measured by, for example, using an Autograph AG-IS manufactured by Shimadzu Corporation under the conditions of a test piece of 10 mm in width at a chuck distance of 500 mm and a tensile speed of 20 mm / min, It can be measured from the slope.

From the viewpoint of the bending resistance of the film, the number of times of bending of the film of the present invention was measured until the film was broken under the conditions of R = 1 mm, 135 DEG, weight 0.75 kgf, and speed 175 cpm, More preferably at least 10,000 times, more preferably at least 20,000 times, more preferably at least 30,000 times, particularly preferably at least 40,000 times, and most preferably at least 50,000 times. If the number of reciprocating bending of the film of the present invention is not less than the lower limit described above, it is easy to suppress folding wrinkles that may occur when the film is bent. The upper limit of the number of reciprocating bending of the film of the present invention is not particularly limited, but it is generally practicable that bending of about 1,000,000 times or less is possible. The number of reciprocating bending can be obtained, for example, as a test sample, a test piece cut out from a film having a thickness of 50 占 퐉 and a width of 10 mm using an MIT endurance fatigue tester (type 0530) manufactured by Toyo Seiki Seisaku- have.

The polyamideimide resin A contained in the film of the present invention has at least a constitutional unit derived from a diamine, a constitutional unit derived from a dicarboxylic acid, and a constitutional unit derived from a tetracarboxylic dianhydride.

The polyamideimide resin A contained in the film of the present invention has a structural unit derived from a diamine. As the diamine, a compound represented by the formula (3) can be mentioned. The polyamide-imide resin A may have a constitutional unit derived from one kind of diamine or a constitutional unit derived from two or more kinds of diamines.

[Chemical Formula 13]

[In the formula (3), X represents a divalent organic group.]

In one preferred embodiment in which the polyamide-imide resin A contained in the film of the present invention has a structural unit derived from a diamine represented by the formula (3), the amount of the structural unit is preferably not less than the total Is preferably 47.5 mol% or more, more preferably 49.0 mol% or more, and still more preferably 49.5 mol% or more based on the constitutional unit. When the amount of the structural unit derived from a diamine represented by the formula (3) is at least the lower limit described above, a polyamideimide resin having a high molecular weight is easily obtained and a high surface hardness is easily exhibited. The amount of the structural unit derived from the diamine represented by the formula (3) is preferably 50.5 mol% or less, more preferably 50.0 mol% or less based on the total structural units contained in the polyamideimide resin A, More preferably 49.99 mol% or less. When the amount of the structural unit derived from a diamine represented by the formula (3) is not more than the above-mentioned upper limit, high transparency and low yellowing tendency are easily exhibited.

X in the formula (3) represents a divalent organic group, preferably an organic group in which a hydrogen atom in an organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. Examples of the divalent organic group include groups represented by formulas (3a) to (3i); A group in which a hydrogen atom in a group represented by any one of formulas (3a) to (3i) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; And a divalent chain hydrocarbon group having 6 or less carbon atoms.

[Chemical Formula 14]

[Of the formulas (3a) to (3i)

* Represents the combined hand,

V ¹ ~V ³ are, each independently, a single _{bond, -O-, -S-, -CH 2 -} , -CH 2 -CH 2 -, -CH (CH 3) -, -C (CH 3) 2 _{-, -C (CF 3) 2} -, -SO 2 - or represents a CO-].

One example is where V ¹ and V ³ are a single bond, -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 to each ring and the bonding position of V ² and V ³ to each ring are preferably meta positions or para positions relative to each ring and are preferably para positions desirable.

Among the groups represented by formulas (3a) to (3i), groups represented by formulas (3d) to (3h) are preferable from the viewpoints of surface hardness and flexibility of the film of the present invention, (3g) is more preferable. From the viewpoints of the surface hardness and flexibility of the film of the present invention, each of V ^{1 to} V ³ is preferably independently a single bond, -O- or S-, more preferably a single bond or O- .

Specific examples of the diamine represented by the formula (3) include aliphatic diamines, aromatic diamines, and mixtures thereof. In the present embodiment, the term "aromatic diamine" refers to a diamine in which an amino group is directly bonded to an aromatic ring, and a part of the structure may contain an aliphatic group or other substituent. 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 fluorene ring, but are not limited thereto. Of these, benzene rings are preferred. The term " aliphatic diamine " means a diamine in which an amino group is bonded directly to an aliphatic group, and an aromatic ring or other substituent may be contained in a part of the structure.

Examples of the aliphatic diamines include alicyclic diamines such as hexamethylene diamine and the like; aliphatic diamines such as 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, '-Diaminodicyclohexylmethane and the like, and the like. These may be used alone or in combination of two or more.

Examples of the aromatic diamine include aromatic diamines such as p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, , And 6-diaminonaphthalene; aromatic diamines having one aromatic ring; 4,4'-diaminodiphenyl ether (ODA), 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether Diaminodiphenyl ether, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 1,4-bis (4-amino (4-aminophenoxy) phenyl) sulfone, bis [4- (4-aminophenoxy) benzene, (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2- Bis (4-aminophenoxy) biphenyl, 9,9-bis (4-aminophenoxy) biphenyl, Aminophenyl) fluorene, 9,9-bis (4-amino-3-methylphenyl) fluorene, 9,9- Amino-3-fluorophenyl) fluorene, or the like having two or more aromatic rings Amines. These may be used alone or in combination of two or more.

The aromatic diamine is preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether , 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 1,4-bis (4-aminophenoxy) benzene, bis [4- Bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (Phenyl) propane, 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) benzidine and 4,4'-bis (4-aminophenoxy) biphenyl, Diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylether, 4,4'-diaminodiphenylsulfone, 1,4- 2-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2- 2'-bis (trifluoro Methyl) benzidine, and 4,4'-bis (4-aminophenoxy) biphenyl. These may be used alone or in combination of two or more.

Among the diamine compounds, at least one selected from the group consisting of aromatic diamines having a biphenyl structure is preferably used in view of the surface hardness, flexibility, bending resistance, transparency and yellowness of the film of the present invention. (4-aminophenoxy) biphenyl and 4,4'-diaminodiphenyl ether, a group consisting of 2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) benzidine, More preferably at least one kind selected from the group consisting of 2,2'-bis (trifluoromethyl) benzidine, and still more preferably 2,2'-bis (trifluoromethyl) benzidine.

From the viewpoint of easily increasing the surface hardness and transparency of the film of the present invention, it is preferable that the polyamide-imide resin A has at least a structural unit derived from a diamine represented by the formula (3e ') in the formula (3) .

[Chemical Formula 15]

Wherein each of R ¹⁰ to R ¹⁷ independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and the hydrogen atom contained in R ¹⁰ to R ¹⁷ , Each independently may be substituted by a halogen atom, and * represents a bond.

In the formula (3e '), R ¹⁰ to R ¹⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms , More preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, wherein the hydrogen atoms contained in R ¹⁰ to R ¹⁷ may be each independently substituted with a halogen atom. In view of the surface hardness, flexibility and transparency of the film of the present invention, R ¹⁰ to R ¹⁷ are each independently preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, Is a hydrogen atom or a trifluoromethyl group.

In this embodiment, the polyamideimide resin A is derived from a diamine (2,2'-bis (trifluoromethyl) benzidine, also referred to as TFMB) represented by the formula (3e ") in the formula (3) Is more preferable. In this case, the film of the present invention has high transparency and the polyamide-imide resin A has a skeleton containing a fluorine element, whereby the solubility of the polyamide-imide resin in a solvent is improved and the film of the present invention is produced The viscosity of the polyamideimide varnish to be used can be suppressed to a low level, so that the film of the present invention can be easily produced.

[Chemical Formula 16]

[In the formula (3e "), * indicates a bonding hand.]

When the polyamide-imide resin A has a constitutional unit derived from two or more diamines, the structural unit derived from a diamine represented by the formula (3e '), preferably the formula (3e ") in the formula (3) Is preferably 30% by mole or more, more preferably 30% by mole or more based on the whole of the structural units derived from diamine contained in the polyamideimide resin A from the viewpoints of improving the transparency of the film of the present invention and ease of production, 50 mol% or more, and more preferably 70 mol% or more. The upper limit of the amount of the structural unit derived from a diamine represented by the formula (3e) in the formula (3) and represented by the formula (3e '), preferably the formula (3e ") is not particularly limited, and the diamine contained in the polyamideimide resin A Based on the whole of the constitutional units derived from the monomers. The proportion of the structural unit derived from the diamine represented by the formula (3e ') or (3e' ') in the formula (3) can be measured using, for example, two-dimensional NMR, .

The polyamideimide resin A contained in the film of the present invention has a structural unit derived from dicarboxylic acid. The polyamide-imide resin A contained in the film of the present invention has a constitutional unit derived from dicarboxylic acid, whereby a constituent unit derived from a tri- or higher-valent carboxylic acid such as 1,3,5-benzenetricarboxylic acid, The solubility in the solvent tends to be lower than in the case of The constituent unit derived from dicarboxylic acid is preferably a constituent unit derived from dicarboxylic acid dichloride. The dicarboxylic acid may be a compound represented by the formula (2). The polyamide-imide resin A may have a constituent unit derived from one kind of dicarboxylic acid or a constituent unit derived from two or more kinds of dicarboxylic acids.

[Chemical Formula 17]

[In the formula (2), Z represents a divalent organic group, and B ¹ and B ² each independently represent OH or a halogen atom, preferably a chlorine atom.

In the polyamideimide resin A, the amount of the constituent unit derived from the dicarboxylic acid represented by the formula (2) is preferably 5 mol% or more, more preferably 5 mol% or more based on the total constituent units contained in the polyamideimide resin A. It is preferably at least 15 mol%, more preferably at least 20 mol%. When the amount of the structural unit derived from the dicarboxylic acid represented by the formula (2) is not lower than the lower limit described above, a high surface hardness is easily produced. The amount of the structural unit derived from the dicarboxylic acid represented by the formula (2) is preferably 45 mol% or less, more preferably 40 mol% or less based on the total structural units contained in the polyamideimide resin A, Or less, more preferably 30 mol% or less. When the amount of the structural unit derived from the dicarboxylic acid represented by the formula (2) is not more than the upper limit of the above range, the film tends to exhibit high flexibility, so that the bending resistance tends to be improved.

Z in the formula (2) represents a divalent organic group, preferably an organic group in which a hydrogen atom in an organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. Examples of the divalent organic group include groups represented by formulas (2a) and (2b); A group in which a hydrogen atom in a group represented by formula (2a) or (2b) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; And a divalent chain hydrocarbon group having 6 or less carbon atoms.

[Chemical Formula 18]

[Chemical Formula 19]

[Of the formulas (2a) and (2b)

* Represents the combined hand,

U 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-, preferably a single bond, -O-, or -Ar-O-Ar-. Ar represents an arylene group having 6 to 20 carbon atoms in which a hydrogen atom may be substituted by a fluorine atom and specific examples thereof include a phenylene group.

Specific examples of the dicarboxylic acid represented by the formula (2) include aromatic dicarboxylic acids, aliphatic dicarboxylic acids and their acid chloride compounds and acid anhydrides, and combinations of two or more thereof You can. Specific examples include terephthalic acid; Isophthalic acid; Naphthalene dicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; A dicarboxylic acid compound of a chain hydrocarbon having 8 or less carbon atoms; The two benzoic single _{bond, -CH 2 -, -C (CH} 3) 2 -, -C (CF 3) 2 -, -SO 2 -, -O-, -S-, -NR 9 -, -C (= O) - or a compound connected by a phenylene group; And their acid chloride compounds. Here, R ⁹ represents a hydrocarbon group of 1 to 12 carbon atoms which may be substituted with a halogen atom.

The dicarboxylic acid represented by the formula (2) preferably includes at least one member selected from terephthalic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-oxybisbenzoic acid and their acid chloride compounds And more preferably at least one selected from the group consisting of terephthaloyl chloride (TPC), 4,4'-biphenyldicarbonyl chloride (BPDOC) and 4,4'-oxybis (benzoyl chloride) More preferably one species, and particularly preferably 4,4'-oxybis (benzoyl chloride) (OBBC).

From the standpoint of enhancing the surface hardness and transparency of the film of the present invention, the polyamide-imide resin A preferably has at least a structural unit represented by the formula (1) in the formula (2).

[Chemical Formula 20]

[In the formula (1), R ¹ to R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and hydrogen atoms contained in R ¹ to R ⁸ are each Independently, may be substituted by a halogen atom,

A represents independently -O-, -S-, -CO- or NR ⁹ -, R ⁹ represents a hydrocarbon group of 1 to 12 carbon atoms which may be substituted by a halogen atom,

m is an integer of 1 to 4,

* Indicates a combined hand.]

The symbols in the formula (1) will be described below.

A represents, independently of each other, -O-, -S-, -CO- or NR ⁹ -, wherein R ⁹ represents a hydrocarbon group of 1 to 12 carbon atoms which may be substituted by a halogen atom. From the viewpoint of flexibility of the film of the present invention, A preferably represents -O- or S-, and more preferably -O-, each independently.

R ¹ to R ⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. In view of the flexibility and surface hardness of the film of the present invention, R ¹ to R ⁸ each independently represent preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms , More preferably a hydrogen atom. Here, the hydrogen atoms contained in R ¹ to R ⁸ may be each independently substituted with a halogen atom.

m is an integer in the range of 1 to 4 and is preferably an integer in the range of 1 to 3, more preferably 1 or 2, and even more preferably 1 in view of the availability of the starting material. When m is within the above range, the availability of the raw material is good and the flexibility of the film of the present invention is easily increased.

In one preferred embodiment of the present invention, the formula (1) is a structural unit represented by the formula (1 '). In this case, the film of the present invention exhibits high surface hardness, low elastic modulus, and high flexibility.

[Chemical Formula 21]

In one preferred embodiment in which the polyamide-imide resin A contained in the film of the present invention has the structural unit represented by the formula (1) or (1 '), the amount of the structural unit is included in the polyamideimide resin A Is preferably not less than 3 mol%, more preferably not less than 5 mol%, more preferably not less than 10 mol%, particularly preferably not less than 20 mol%, based on the total constituent units. If the amount of the constituent unit represented by the formula (1) or (1 ') is not less than the above lower limit, the resin film tends to exhibit high flexibility, and therefore its bending resistance tends to be improved. The amount of the structural unit represented by the formula (1) or (1 ') is preferably not more than 45 mol%, more preferably not more than 40 mol%, based on the total structural units contained in the polyamideimide resin A, Or less, more preferably 30 mol% or less. If the amount of the structural unit represented by the formula (1) or (1 ') is not more than the upper limit, the glass transition temperature of the resin film tends to be improved.

From the standpoint of enhancing the surface hardness, elastic modulus and flexibility of the film of the present invention, the polyamideimide resin A is preferably a polyamideimide resin having at least a structural unit derived from a dicarboxylic acid represented by the formula (1) in the formula (2) . When the polyamide-imide resin has a constituent unit derived from at least two dicarboxylic acids, the amount of the constituent unit derived from the dicarboxylic acid represented by the formula (1) in the formula (2) Is preferably not less than 5 mol%, more preferably not less than 7 mol%, further preferably not less than 9 mol%, based on the entire structural units derived from dicarboxylic acid contained in the polyamideimide resin A from the viewpoints of flexibility, Mol% or more, particularly preferably 11 mol% or more. The upper limit of the amount of the structural unit derived from the dicarboxylic acid represented by the formula (1) in the formula (2) is not particularly limited, and the total amount of the structural units derived from the dicarboxylic acid contained in the polyamideimide resin A Based on 100 mol% or less. The proportion of the structural unit derived from dicarboxylic acid represented by the formula (1) in the formula (2) in the formula (2) can be measured using, for example, two-dimensional NMR or from the introduction ratio of the raw material.

The polyamideimide resin A contained in the film of the present invention has a structural unit derived from a tetracarboxylic dianhydride. As the tetracarboxylic dianhydride, a compound represented by the formula (4) may be mentioned. The polyamideimide resin A may have a constituent unit derived from one kind of tetracarboxylic dianhydride or may have a constituent unit derived from two or more kinds of tetracarboxylic dianhydrides.

[Chemical Formula 22]

[In the formula (4), Y represents a tetravalent organic group.]

In the polyamide-imide resin A contained in the film of the present invention, the amount of the constituent unit derived from the tetracarboxylic dianhydride represented by the formula (4) , Preferably at least 5 mol%, more preferably at least 10 mol%, and even more preferably at least 20 mol%. When the amount of the structural unit derived from the tetracarboxylic dianhydride represented by the formula (4) is at least the lower limit described above, the ratio of the structural unit derived from the dicarboxylic acid can be suppressed and the polyamideimide resin having a Tg of 370 캜 or lower . The amount of the constituent unit derived from the tetracarboxylic dianhydride represented by the formula (4) is preferably 45 mol% or less, more preferably 40 mol% or less based on the total constituent units contained in the polyamideimide resin A Mol% or less, more preferably 30 mol% or less. When the amount of the constituent unit derived from the tetracarboxylic dianhydride represented by the formula (4) is not more than the upper limit, the proportion of the constituent unit derived from the dicarboxylic acid can be increased and a high surface hardness is easily exhibited.

Y in the formula (4) represents a tetravalent organic group, preferably an organic group in which a hydrogen atom in an organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. The organic group is preferably an organic group which may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. The organic group is preferably a tetravalent organic group having 4 to 40 carbon atoms. The hydrocarbon group and the fluorine-substituted hydrocarbon group preferably have 1 to 8 carbon atoms. Examples of the tetravalent organic group include groups represented by formulas (4a) to (4j); A group in which a hydrogen atom in a group represented by the formulas (4a) to (4j) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; And a tetravalent chain hydrocarbon group having 6 or less carbon atoms.

(23)

[Of the formulas (4a) to (4j)

* Represents the combined hand,

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 may be substituted by a fluorine atom and specific examples thereof include a phenylene group.

Among the groups represented by the formulas (4a) to (4j), the groups represented by the formulas (4g), (4i) and (4j) are preferable from the viewpoints of the surface hardness and the flexibility of the film of the present invention, (4g) is more preferable. In view of the surface hardness and flexibility of the film of the present invention, W ¹ is preferably a single bond, -O-, -CH ₂ -, -CH ₂ -CH ₂ -, -CH (CH ₃ ) -, -C CH _{3) 2} - or C (CF _{3) 2} - which is preferred, a single _{bond, -O-, -CH 2 -, -CH} (CH 3) -, -C (CH 3) 2 - or C (CF _{3) 2-in} is more preferable and a single bond, -C (CH _{3) 2} - or C (CF _{3) 2} - which is more preferred, a single bond, or C (CF _{3) 2} - is particularly preferred Do.

Specific examples of the tetracarboxylic acid dianhydrides represented by the formula (4) include aromatic tetracarboxylic dianhydrides and aliphatic tetracarboxylic dianhydrides. One kind of tetracarboxylic acid dianhydride may be used, or two or more kinds of them may be used in combination.

Specific examples of the aromatic tetracarboxylic acid dianhydrides include non-condensed polycyclic aromatic tetracarboxylic dianhydrides, monocyclic aromatic tetracarboxylic dianhydrides and condensed polycyclic aromatic tetracarboxylic dianhydrides. Examples of the non-condensed polycyclic aromatic tetracarboxylic acid dianhydride include 4,4'-oxydiphthalic dianhydride (OPDA), 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,2' 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA), 2,2', 3,3'-biphenyltetracarboxylic acid 2 (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-di Bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4 '- (hexafluoroisopropylidene) diphthalic dianhydride, 1,2-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2- Bis (3,4-dicarboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, , 4,4 '- (p- phenylenedimaleimide oxy) diphthalic dianhydride, 4,4' - there may be mentioned (m- phenylenedimaleimide oxy) diphthalic acid dianhydride. Examples of the monocyclic aromatic tetracarboxylic acid dianhydride include 1,2,4,5-benzenetetracarboxylic dianhydride. As the condensed polycyclic aromatic tetracarboxylic acid dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride can be mentioned. These may be used alone or in combination of two or more.

Among these, 4,4'-oxydiphthalic dianhydride, 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride, 2,2', 3,3'-benzophenonetetracarboxylic acid Biphenyltetracarboxylic dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 3,3', 4,4'-di Bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA), 1,2- (2,3-dicarboxyphenyl) ethane dianhydride, 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, 4,4 '- (p-phenylenedioxy) diphthalic acid 2-anhydride and 4,4 '- (m-phenylenedioxy) diphthalic acid dianhydride. More preferred are 4,4'-oxydiphthalic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride , 4,4'- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA), bis (3,4-dicarboxyphenyl) methane dianhydride and 4,4 '- (p-phenylenedioxy) 2 anhydride. These may be used alone or in combination of two or more.

Examples of the aliphatic tetracarboxylic acid dianhydride include cyclic or acyclic aliphatic tetracarboxylic dianhydrides. The cyclic aliphatic tetracarboxylic acid dianhydride is tetracarboxylic dianhydride having an alicyclic hydrocarbon structure, and specific examples thereof include 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,3,4-cyclo Butane tetracarboxylic acid dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride and the like, cycloalkanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5 , 6-tetracarboxylic dianhydride, dicyclohexyl 3,3'-4,4'-tetracarboxylic dianhydride, and their positional isomers. These may be used alone or in combination of two or more. Specific examples of the non-cyclic aliphatic tetracarboxylic acid dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-pentanetetracarboxylic dianhydride and the like, Or two or more of them may be used in combination. The cyclic aliphatic tetracarboxylic acid dianhydride and the non-cyclic aliphatic tetracarboxylic dianhydride may be used in combination.

Among these tetracarboxylic dianhydrides, 4,4'-oxydiphthalic dianhydride, 3,3 ', 4,4'-tetraacetic acid dianhydride, 4,4'-oxydiphthalic dianhydride, 4,4'-oxydiphthalic dianhydride and the like are preferable from the viewpoints of easily increasing the surface hardness, flexibility, bending resistance and transparency of the film, , 4'-benzophenonetetracarboxylic dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic dianhydride, 3, 4 '-diphenylsulfone tetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 4,4' - (hexafluoroisopropylidene) 2-anhydride and a mixture thereof are preferable, and 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) and 4,4' - (hexafluoroisopropylidene) diphthalic dianhydride 6FDA), and mixtures thereof are more preferable, and 4,4 '- (hexafluoroisopropylidene) diphthalic dianhydride is more preferable.

The polyamideimide resin A preferably has at least a structural unit derived from a tetracarboxylic dianhydride represented by the formula (4g ') in the formula (4). In this case, the film of the present invention has high transparency and the polyamide-imide resin A has a high flexural skeleton, so that the solubility of the polyamide-imide resin in a solvent is improved and the film used for producing the film of the present invention The viscosity of the polyamide imide varnish can be suppressed to a low level, so that the film of the present invention can be easily produced.

≪ EMI ID =

Wherein R ¹⁸ to R ²⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and the hydrogen atoms contained in R ¹⁸ to R ²⁵ , Each independently may be substituted by a halogen atom, and * represents a bond.

In formula (4g '), R ¹⁸ to R ²⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms , More preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, wherein the hydrogen atoms contained in R ¹⁸ to R ²⁵ may be each independently substituted with a halogen atom. In view of the surface hardness and flexibility of the film of the present invention, R ¹⁸ to R ²⁵ are each independently preferably a hydrogen atom, a methyl group, a fluoro group, a chloro group or a trifluoromethyl group, A hydrogen atom or a trifluoromethyl group.

In the above preferred embodiment, the polyamideimide resin A preferably has at least a structural unit derived from a tetracarboxylic dianhydride represented by the formula (4g ") in the formula (4). In this case, the film of the present invention has high transparency and the polyamide-imide resin A has a skeleton containing a fluorine element, whereby the solubility of the polyamide-imide resin in a solvent is improved, and the film of the present invention is produced The viscosity of the polyamideimide varnish to be used can be suppressed to a low level, so that the film of the present invention can be easily produced.

(25)

[In the formula (4g "), * indicates a bonding hand.]

When the polyamideimide resin A has a constituent unit derived from at least two kinds of tetracarboxylic dianhydrides, Y in the formula (4) is preferably tetracarboxylic acid represented by the formula (4g '), preferably the formula (4g' The amount of the constituent unit derived from the maleic anhydride is preferably from 0.01 to 10 parts by weight based on the entirety of the constituent units derived from the tetracarboxylic dianhydride contained in the polyamideimide resin A from the viewpoint of improving transparency of the film and ease of production, 50 mol% or more, more preferably 60 mol% or more, and still more preferably 70 mol% or more. The upper limit of the amount of the structural unit derived from the tetracarboxylic dianhydride represented by the formula (4g '), preferably the formula (4g' ') in the formula (4) is not particularly limited, Based on the entirety of the constituent units derived from the tetracarboxylic dianhydride contained, may be 100 mol% or less. The proportion of the structural unit derived from diamine represented by the formula (4g ') or (4g' ') in the formula (4) can be measured using two-dimensional NMR, for example, And the like.

The polyamide-imide resin A contained in the film of the present invention may also have a structural unit derived from a tricarboxylic acid. Examples of the tricarboxylic acid include aromatic tricarboxylic acids, aliphatic tricarboxylic acids, and acidic chloride compounds such as their derivatives, and acid anhydrides. One type of tricarboxylic acid may be used, or two or more types may be used in combination. Specific examples include anhydrides of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalenetricarboxylic acid-2,3-anhydride; A compound in which phthalic anhydride and benzoic acid are linked by a single bond, -O-, -CH ₂ -, -C (CH ₃ ) ₂ -, -C (CF ₃ ) ₂ -, -SO ₂ - or phenylene group .

In one preferred embodiment of the present invention, the polyamideimide resin A contained in the film of the present invention is a polyamideimide resin A which is obtained by reacting a dicarboxylic acid (a dicarboxylic acid-based compound such as an acid chloride), a diamine and a tetracarboxylic acid (A tetracarboxylic acid-based derivative such as a maleic anhydride or a maleic anhydride), and optionally a tricarboxylic acid (a tricarboxylic acid compound-based derivative such as an acid chloride compound or a tricarboxylic acid anhydride) with a condensation polymer to be. In this embodiment, the polyamide-imide resin A has a constitutional unit represented by the formula (5) and a constitutional unit represented by the following formula (6).

(26)

[In the formula (5), X and Y have the same meanings as defined above.]

(27)

[In the formula (6), X and Z are as defined above.]

X, Y and Z in the formulas (5) and (6) have the same meanings as X in the formula (3), Y in the formula (4) and Z in the formula (2) The above-described preferable description regarding X, Y and Z in the formula (4) also applies to X, Y and Z in the formulas (5) and (6). The constituent unit represented by the formula (5) is usually a constituent unit derived from a diamine and a tetracarboxylic acid, and the constituent unit represented by the formula (6) is usually a constituent unit derived from a diamine and a dicarboxylic acid.

In a preferred embodiment of the present invention, the polyamide-imide resin A contained in the film of the present invention further contains a structural unit represented by the formula (7) and / or a structural unit represented by the following formula (8) .

(28)

[In the formula (7), X ¹ represents a divalent organic group and Y ¹ represents a tetravalent organic group.]

[Chemical Formula 29]

[In the formula (8), X ² represents a divalent organic group and Y ² represents a trivalent organic group.]

In formula (7), Y ¹ is, independently of each other, a tetravalent organic group, preferably an organic group in which hydrogen atoms in an organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. Examples of Y ¹ include a group represented by the formulas (4a) to (4j) and a quadrivalent chain hydrocarbon group having 6 or less carbon atoms. The polyamideimide resin A may have one constituent unit represented by the formula (7), and two or more different constituent units represented by the formula (7) in Y ¹ and / or X ¹ .

In formula (8), Y ² is, independently of each other, a trivalent organic group, preferably an organic group in which a hydrogen atom in an organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. Examples of Y ² include a group in which any one of the bonding hands represented by the formulas (4a) to (4j) is substituted with a hydrogen atom, and a trivalent chain hydrocarbon having 6 or less carbon atoms. The polyamideimide resin A may have one constituent unit represented by the formula (8), and two or more different constituent units represented by the formula (7) in Y ² and / or X ² .

In the formulas (7) and (8), X ¹ and X ² are, independently of each other, a divalent organic group, preferably a hydrogen atom in an organic group may be substituted by a hydrocarbon group or a fluorine- It is an organic device. X ¹ and X ² are groups represented by formulas (3a) to (3i); A group in which a hydrogen atom in a group represented by any one of formulas (3a) to (3i) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; And a chain hydrocarbon group having 6 or less carbon atoms.

In one preferred embodiment of the present invention, the polyamide-imide resin A contained in the film of the present invention is a polyamide-imide resin A comprising the structural units represented by the formulas (5) and (6) And constituent units represented by the formula (8). In this aspect, the amount of the constituent unit represented by the formula (5) and the formula (6) contained in the polyamideimide resin A is preferably in the range of the formula (5) and the formula Is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more, based on the total constitutional units represented by formulas (7) and (8) . The upper limit of the amount of the constituent unit represented by the formula (5) and the formula (6) contained in the polyamideimide resin A is determined by the formula (5) and the formula (6) And 100% or less based on the total constitutional unit represented by the formula (8). The ratio can be measured using, for example, two-dimensional NMR, or can be calculated from the introduction ratio of the raw material.

The glass transition temperature Tg calculated by tan? In the dynamic viscoelasticity measurement (DMA measurement) of the polyamideimide resin A contained in the film of the present invention is preferably 380 占 폚 or less, more preferably 379 占 폚 or less, More preferably 378 DEG C or less, for example, 370 DEG C or less. When the glass transition temperature Tg of the polyamide-imide resin A is less than the upper limit or is not more than the upper limit of the above range, the film of the present invention exhibits high surface hardness and tends to lower the elastic modulus and increase the flexibility. The lower limit of the glass transition temperature Tg is not particularly limited, but is generally 300 DEG C or higher. The method of calculating the glass transition temperature by the tan? In the dynamic viscoelasticity measurement (DMA measurement) can be specifically carried out according to the embodiment.

The weight average molecular weight (Mw) of the polyamideimide resin A contained in the film of the present invention is preferably 5,000 or more, more preferably 10,000 or more, still more preferably 50,000 or more, particularly preferably 70,000 or more Is not more than 800,000, more preferably not more than 600,000, more preferably not more than 500,000, particularly preferably not more than 450,000. When the weight average molecular weight (Mw) of the polyamide-imide resin A is not lower than the above-mentioned lower limit, the bending resistance of the film of the present invention is easily increased. When the weight average molecular weight (Mw) of the polyamide-imide resin A is not more than the upper limit, the solubility of the polyamide-imide resin in a solvent is improved, and the viscosity of the polyamide-imide varnish used in producing the film of the present invention is suppressed to be low The film of the present invention can be easily produced. Further, since the stretching of the film is facilitated, the processability is good. The weight average molecular weight (Mw) can be determined, for example, by GPC measurement and standard polystyrene conversion. Specifically, the weight average molecular weight (Mw) can be obtained by the method described in the Examples.

The polyamideimide resin A contained in the film of the present invention preferably contains a halogen atom, and more preferably contains a fluorine atom. Specific examples of fluorine-substituted groups include a fluoro group and a trifluoromethyl group. Since the polyamide-imide resin A contains a halogen atom, the yellowness degree (YI value) of the film of the present invention is easily reduced, and both the flexibility and the bend resistance can be easily satisfied. The halogen atom is preferably a fluorine atom from the viewpoint of reduction in yellowness (improvement in transparency) of the film of the present invention, reduction of water absorption rate, and flex resistance. From the above viewpoint, the polyamideimide resin A preferably has at least a constituent unit derived from a fluorine atom-containing diamine and / or a fluorine atom-containing tetracarboxylic acid dianhydride.

The content of the halogen atom in the polyamide-imide resin A is preferably from 1 to 100 parts by weight based on 100 parts by weight of the polyamide-imide resin A contained in the film of the present invention, from the viewpoints of reduction in yellowness (improvement in transparency) Is preferably 1% by mass to 40% by mass, more preferably 3% by mass to 35% by mass, and still more preferably 5% by mass to 32% by mass, based on the mass.

From the viewpoint of improving the visibility and quality of the film of the present invention, the film of the present invention may be an additive having a light absorbing function in addition to the polyamide-imide resin. Examples of the additive having a light absorbing function include an ultraviolet absorber, a bluing agent and the like. The additive having a light absorbing function is preferably selected from the group consisting of an ultraviolet absorber and a bluing agent since it is easy to improve the visibility and quality of the film of the present invention. The film of the present invention may contain one kind of additive having a light absorbing function or two or more kinds of additives having a light absorbing function. When additives such as ultraviolet absorber and bluing agent are added to a film containing a conventional polyamide-imide resin, since these additives have low heat resistance, a film containing a polyamide-imide resin can be obtained at a high temperature Decomposition or the like occurs in the step of heating under the condition, and the quality of the film is deteriorated. For this reason, for example, it has been necessary to add these additives to a layer different from the layer containing the polyamideimide resin and to combine with the polyamideimide film. For example, when a film is produced using the resin composition of the present invention or a composition comprising the polyamide-imide resin obtained by the production method of the present invention, the imidization ratio of the polyamide- Can be increased. Therefore, even when a film is produced under a relatively low-temperature heating condition, the imidization ratio can be increased and a sufficiently high surface hardness can be achieved. Therefore, even when an additive having a light-absorbing function is added to the same layer as the layer containing the polyamide-imide resin, decomposition of these additives can be suppressed and deterioration of the film quality can be suppressed.

The ultraviolet absorber may be appropriately selected from those conventionally used as an ultraviolet absorber in the field of resin materials. The ultraviolet absorber may contain a compound that absorbs light having a wavelength of 400 nm or less. Examples of the ultraviolet absorber include at least one compound selected from the group consisting of benzophenone compounds, salicylate compounds, benzotriazole compounds, and triazine compounds. When the film of the present invention contains an ultraviolet absorber, deterioration of the polyamide-imide resin is suppressed, so that the visibility of the film can be enhanced. In the present specification, the term "system compound" refers to a derivative of a compound to which the "system compound" is attached. For example, the "benzophenone compound" refers to a compound having a substituent bonded to benzophenone and benzophenone as a matrix skeleton.

When the film of the present invention contains an ultraviolet absorber, the amount of the ultraviolet absorber to be added may be appropriately selected depending on the kind of the ultraviolet absorber to be used, but it is preferably 1% by mass or more, more preferably 1% , More preferably not less than 3 mass%, preferably not more than 10 mass%, more preferably not more than 8 mass%, still more preferably not more than 6 mass%. It is preferable to adjust the addition amount so that the light transmittance at 400 nm is about 20 to 60%, since it is easy to increase the light resistance of the film of the present invention and it is easy to obtain a film with high transparency Do.

The bluing agent may be appropriately selected from those conventionally used as a bluing agent in the field of resin materials. The blueing agent is an additive (dye, pigment) which absorbs light in a wavelength region such as orange to yellow in the visible light region and adjusts the color. Examples of the additive (dye, pigment) Blue, and other organic dyes and pigments such as pigments such as phthalocyanine-based blueing agents and condensed polycyclic blueing agents. The bluing agent is not particularly limited, but from the viewpoints of heat resistance, light resistance and solubility, a condensation polycyclic bluing agent is preferable, and an anthraquinone bluing agent is more preferable. From the viewpoint of heat resistance, it is preferable that the bluing agent has a thermal decomposition temperature of 200 캜 or more. Examples of the condensed polycyclic blueing agent include anthraquinone-based blueing agents, indigo-based blueing agents and phthalocyanine-based blueing agents.

When the film of the present invention contains a bluing agent, the amount of the bluing agent to be added may be appropriately selected depending on the kind of the bluing agent to be used, but it is preferably 0.01% by mass or more, more preferably 0.01% Is preferably 0.02 mass% or more, more preferably 0.03 mass% or more, preferably 1.0 mass% or less, more preferably 0.5 mass% or less, further preferably 0.2 mass% or less.

The film of the present invention may further contain an inorganic material such as inorganic particles in addition to the polyamide-imide resin. Examples of the inorganic material include inorganic particles such as titania particles, alumina particles, zirconia particles and silica particles, and silicon compounds such as quaternary alkoxysilanes such as tetraethylorthosilicate. From the viewpoint of stability of the polyamide imide varnish, the inorganic material is preferably an inorganic particle, particularly a silica particle. The inorganic particles may be bonded together by a molecule having a siloxane bond.

The average primary particle diameter of the inorganic particles is preferably from 10 to 100 nm, more preferably from 20 to 80 nm, from the viewpoints of film transparency, mechanical properties, and inhibition of aggregation of the inorganic particles. In the present invention, the average primary particle size can be determined by measuring 10 points of the diameters in the positive direction by a transmission electron microscope (TEM) and calculating the average value thereof.

When the film of the present invention contains an inorganic material, the content of the inorganic material in the film is preferably 0 to 90 mass%, more preferably 0 to 60 mass%, and still more preferably 0 to 50 mass% Is 0 to 40% by mass. When the content of the inorganic material is within the above range, the transparency and the mechanical properties of the film tends to be compatible with each other.

The film of the present invention may contain other additives. Examples of other additives include antioxidants, release agents, stabilizers, flame retardants, pH adjusters, silica dispersants, lubricants, thickeners and leveling agents. When the film of the present invention contains other additives, the content of the other additives is preferably 0% by mass or more and 20% by mass or less, more preferably 0% by mass or more and 10% by mass or less, based on the mass of the film of the present invention % Or less.

(Layer composition)

The layer structure of the film of the present invention is not particularly limited and may be a single layer or a multilayer of two or more layers. When the film of the present invention further contains an additive such as an additive having a light absorbing function, it is preferable that the additive and the polyamide-imide resin are contained in one layer from the viewpoint of thinning of the image display apparatus and economical efficiency . In this case, it is more preferable that the film of the present invention is a monolayer containing the additive and the polyamide-imide resin, or a laminate having at least the layer containing the additive and the polyamide-imide resin. From the viewpoint of the impact resistance characteristics, it is preferable that the film of the present invention has a multilayer structure of two or more layers including at least a layer containing a polyamideimide resin. When the film of the present invention further contains an additive such as an additive having a light absorbing function, it may be a layered product having at least a layer containing the additive and a polyamideimide resin, or a layer containing the additive and a layer containing a polyamideimide Or may be a laminate having at least a layer containing a resin.

The film of the present invention may be a polyamideimide laminate obtained by laminating at least one functional layer in addition to the aforementioned layer. Examples of the functional layer include layers having various functions such as a hard coating layer, an ultraviolet absorbing layer, a pressure-sensitive adhesive layer, a refractive index-adjusting layer, and a primer layer. The film of the present invention may have one or more functional layers. In addition, one functional layer may have a plurality of functions. For example, the functional layer may be formed on a film containing a polyamide-imide resin to obtain a multilayered film.

The present invention relates to a resin composition comprising a structural unit derived from a diamine, a structural unit derived from a dicarboxylic acid, and a structural unit derived from a tetracarboxylic acid dianhydride and having an imidization ratio of 60% A polyamide-imide resin B, and a solvent. Further, the film of the present invention containing the polyamideimide resin A is produced using the resin composition of the present invention at least including, for example, a polyamideimide resin B and a solvent.

The resin composition of the present invention includes a polyamideimide resin B having an imidization rate of 60% or more as measured by two-dimensional NMR. Since the resin composition of the present invention is a composition used for producing a film containing a polyamideimide resin and contains the polyamideimide resin B having a high imidization rate as described above, The imidization rate of the amideimide resin can be sufficiently increased, and as a result, a polyamideimide film having a sufficiently high surface hardness can be obtained. When the imidization rate of the polyamide-imide resin contained in the resin composition is lower than 60%, the polyamide-imide resin tends to become excessively flexible primary structure polyamide-imide. Therefore, the surface hardness of the finally obtained polyamide- I can not. From the viewpoint of surface hardness, the imidization rate of the polyamideimide resin B is preferably 80% or more, more preferably 90% or more, still more preferably 95% or more. The higher the imidization rate is, the better the higher the rate of imidization is, and the upper limit is not particularly limited and may be 100% or less.

The imidization rate of the polyamideimide resin B is preferably set such that the ratio of the number of moles of the imide bond in the polyamideimide resin B to the ratio of the number of moles of the imide bond in the polyamideimide resin B to twice the number of moles of the constituent unit derived from the tetracarboxylic acid dianhydride in the polyamideimide resin B And is measured by two-dimensional NMR in the present specification. The imidization ratio of the polyamide-imide resin B is determined by adding a polyamide-imide resin B precipitated and re-dissolved by a reprecipitation method to a resin composition (varnish) The measurement can be performed using two-dimensional NMR using a predetermined solution obtained by dissolving as a measurement sample. Examples of the poor solvent include an alcohol-based solvent, water, a saturated hydrocarbon-based solvent and an aromatic solvent, and preferably an alcohol-based solvent and water. Examples of the alcoholic solvent include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-isobutanol, 1-heptanol, -Hexanol, 3-hexanol, ethylene glycol, glycerin and the like, and preferred examples thereof include methanol, ethanol, 1-propanol and 2-propanol, more preferably methanol and ethanol. Two or more of these poor solvents may be mixed.

Examples of the deuterated solvent as a good solvent include deuterated dimethylsulfoxide (DMSO-d6).

The imidization rate is expressed by the following equation (9).

Imidization ratio (%) = [1- (number of moles of repeating units having an amic acid) / (number of moles of repeating units having an imide bond)] x 100 Equation (9)

The polyimide resin or polyimide film can be obtained by appropriately integrating a signal derived from a repeating unit having an amic acid in the ¹ H-NMR spectrum and a signal derived from a repeating unit having an imide bond , And the imidization rate is obtained by applying the equation (9). Here, the amic acid includes an amide bond and a carboxyl group, which are precursors of imide bonds.

The polyamide-imide resin or the polyamide-imide film may be obtained, for example, from a repeating unit having an amic acid in a two-dimensional NMR spectrum measured by deuterated dimethyl sulfoxide (DMSO-d6) and a repeating unit having an imide bond The imidization rate can be obtained by converting the value obtained by appropriately integrating the signal obtained by the integration. As a conversion method, a correlation of the value of the imidization ratio obtained by the ¹ H-NMR spectrum is applied.

In order to obtain the imidization rate with high precision, a conventionally known or conventional technique is applied. Such a technique includes, for example, increasing the S / N ratio, which is the ratio of the signal to the noise, and integrating the obtained two-dimensional NMR spectrum with high precision. In order to obtain the imidization rate with higher precision, it is preferable that the S / N ratio is 6 or more. As a method for increasing the S / N ratio, for example, a method of increasing the sample concentration, increasing the number of integrations, and using a high-sensitivity NMR measuring device can be given. Examples of the high-sensitivity NMR measuring device include an NMR device having a stronger magnetic field and an NMR device using a cryoflower. As a method of accurately integrating a two-dimensional NMR spectrum, for example, phase correction is performed and baseline correction is performed. When a signal on a two-dimensional NMR spectrum derived from a structure other than a repeating unit having an amic acid and a repeating unit having an imide bond is overlapped, the signal is integrated without including the intensity of the signal, Can be obtained.

The glass transition temperature Tg calculated by tan? In the dynamic viscoelasticity measurement (DMA measurement) of the polyamideimide resin B is preferably 380 占 폚 or less, more preferably 379 占 폚 or less, still more preferably 378 占 폚 or less , For example, 370 占 폚 or less. When the glass transition temperature Tg of the polyamide-imide resin B is less than the upper limit or is not more than the upper limit, the film obtained using the resin composition of the present invention tends to exhibit high surface hardness, , It is easy to increase flexibility. The lower limit of the glass transition temperature Tg is not particularly limited, but is generally 300 DEG C or higher. The method of calculating the glass transition temperature by the tan? In the dynamic viscoelasticity measurement (DMA measurement) can be specifically carried out according to the embodiment.

The weight average molecular weight (Mw) of the polyamideimide resin B contained in the film of the present invention is preferably 5,000 or more, more preferably 10,000 or more, still more preferably 50,000 or more, particularly preferably 70,000 or more, Is not more than 800,000, more preferably not more than 600,000, more preferably not more than 500,000, particularly preferably not more than 450,000. When the weight average molecular weight (Mw) of the polyamide-imide resin B is not lower than the lower limit described above, it is easy to increase the bending resistance of the film obtained using the resin composition of the present invention. When the weight average molecular weight (Mw) of the polyamide-imide resin B is not more than the above-mentioned upper limit, the solubility of the polyamide-imide resin in a solvent is improved and the viscosity of the resin composition of the present invention can be suppressed to a low level. It becomes easier to do. Further, since the stretching of the film is facilitated, the processability is good. The weight average molecular weight (Mw) can be determined, for example, by GPC measurement and standard polystyrene conversion. Specifically, the weight average molecular weight (Mw) can be obtained by the method described in the Examples.

The polyamideimide resin B contained in the resin composition of the present invention has a constitutional unit derived from a diamine, a constitutional unit derived from a dicarboxylic acid, and a constitutional unit derived from a tetracarboxylic dianhydride. With respect to the specific examples and preferred embodiments of the diamine, dicarboxylic acid and tetracarboxylic dianhydride, the above description concerning the polyamideimide resin A is equally applicable. The polyamideimide resin B contained in the resin composition of the present invention may also have a constituent unit derived from a tricarboxylic acid in the same manner as the polyamideimide resin A. As the tricarboxylic acid, the above description regarding the polyamideimide resin A is equally applicable.

In one preferred embodiment of the present invention, the polyamideimide resin B contained in the resin composition of the present invention is a polyamideimide resin B which is obtained by dissolving dicarboxylic acid (dicarboxylic acid-based compound such as acid chloride), diamine and tetracarboxylic acid (A tetracarboxylic acid-based compound such as a carboxylic acid dianhydride, etc.) and optionally a tricarboxylic acid (a tricarboxylic acid compound-based compound such as an acid chloride compound or a tricarboxylic acid anhydride) It is a polymer. In this embodiment, the polyamide-imide resin B, similarly to the polyamide-imide resin A, has a constituent unit represented by the formula (5) and a constituent unit represented by the formula (6).

(30)

[In the formula (5), X and Y have the same meanings as defined above.]

(31)

[In the formula (6), X and Z are as defined above.]

X, Y and Z in the formulas (5) and (6) have the same meanings as X in the formula (3), Y in the formula (4) and Z in the formula (2) The above-described preferable description regarding X, Y and Z in the formula (4) also applies to X, Y and Z in the formulas (5) and (6). The constituent unit represented by the formula (5) is usually a constituent unit derived from a diamine and a tetracarboxylic acid, and the constituent unit represented by the formula (6) is usually a constituent unit derived from a diamine and a dicarboxylic acid.

In one preferred embodiment of the present invention, the polyamide-imide resin B contained in the resin composition of the present invention further contains a structural unit represented by the formula (7) and / or a constituent unit represented by the following formula (8) Units.

(32)

[In the formula (7), X ¹ represents a divalent organic group and Y ¹ represents a tetravalent organic group.]

(33)

[In the formula (8), X ² represents a divalent organic group and Y ² represents a trivalent organic group.]

In formula (7), Y ¹ is, independently of each other, a tetravalent organic group, preferably an organic group in which hydrogen atoms in an organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. Examples of Y ¹ include a group represented by the formulas (4a) to (4j) and a quadrivalent chain hydrocarbon group having 6 or less carbon atoms. The polyamideimide resin B may have one constituent unit represented by the formula (7), and two or more different constituent units represented by the formula (7) in Y ¹ and / or X ¹ .

In formula (8), Y ² is, independently of each other, a trivalent organic group, preferably an organic group in which a hydrogen atom in an organic group may be substituted by a hydrocarbon group or a fluorine-substituted hydrocarbon group. The organic group is preferably a trivalent organic group having 4 to 40 carbon atoms. The number of carbon atoms of the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably 1 to 8. The number of carbon atoms of the organic group is preferably 4 to 40. Examples of Y ² include a group in which one of the bonding hands of the groups represented by the above formulas (4a) to (4j) is substituted with a hydrogen atom, and a trivalent chain hydrocarbon group having 6 or less carbon atoms. The polyamide-imide resin B may have one constituent unit represented by the formula (8), and two or more different constituent units represented by the formula (7) in Y ² and / or X ² . The example of W ^{1 in} the formula is the same as the example of W ¹ in the description of Y ¹ .

In the formulas (7) and (8), X ¹ and X ² are, independently of each other, a divalent organic group, preferably a hydrogen atom in an organic group may be substituted by a hydrocarbon group or a fluorine- It is an organic device. The organic group is preferably a divalent organic group having 4 to 40 carbon atoms. The number of carbon atoms of the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably 1 to 8. The number of carbon atoms of the organic group is preferably 4 to 40. X ¹ and X ² are groups represented by formulas (3a) to (3i); A group in which a hydrogen atom in a group represented by any one of formulas (3a) to (3i) is substituted with a methyl group, a fluoro group, a chloro group or a trifluoromethyl group; And a chain hydrocarbon group having 6 or less carbon atoms.

In one preferred embodiment of the present invention, the polyamide-imide resin B contained in the resin composition of the present invention is a polyamide-imide resin B having a structural unit represented by the formula (5) and a formula (6) Or a structural unit represented by the formula (8). In this aspect, the amount of the constitutional unit represented by the formula (5) and the formula (6) contained in the polyamideimide resin B is preferably from 5% by weight to 5% by weight, Is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more, based on the total constitutional units represented by formulas (7) and (8) . The upper limit of the amount of the constituent unit represented by the formula (5) and the formula (6) contained in the polyamideimide resin B can be determined by the formula (5) and the formula (6) And 100% or less based on the total constitutional unit represented by the formula (8). The ratio can be measured using, for example, two-dimensional NMR, or can be calculated from the introduction ratio of the raw material.

The polyamide-imide resin B contained in the resin composition of the present invention preferably contains a halogen atom in the same manner as the polyamide-imide resin A, and more preferably contains a fluorine atom. Specific examples of fluorine-substituted groups include a fluoro group and a trifluoromethyl group. Since the polyamide-imide resin B contains a halogen atom, it is easy to reduce the yellowness (YI value) of a film obtained using the resin composition of the present invention, and to easily achieve both flexibility and bend resistance. The halogen atom is preferably a fluorine atom from the standpoint of reduction in yellowness (improvement of transparency) of the film, reduction of the water absorption rate, and flex resistance. From the above viewpoint, the polyamideimide resin B preferably has at least a constituent unit derived from a fluorine atom-containing diamine and / or a fluorine atom-containing tetracarboxylic acid dianhydride.

The content of the halogen atom in the polyamide-imide resin B is preferably from 0.1 to 10 parts by weight, more preferably from 1 to 20 parts by weight, based on the total weight of the polyamideimide resin B (B) contained in the resin composition of the present invention, Is preferably from 1 to 40 mass%, more preferably from 3 to 35 mass%, and still more preferably from 5 to 32 mass%, based on the mass of the polymer.

The solvent contained in the resin composition of the present invention is not particularly limited as long as the polyamide-imide resin B can be dissolved. Examples of such a solvent include amide solvents such as N, N-dimethylacetamide (DMAc) and N, N-dimethylformamide; lactone solvents such as? -butyrolactone and? -valerolactone; Sulfur-containing solvents such as dimethylsulfone, dimethylsulfoxide and sulfolane; Carbonate solvents such as ethylene carbonate and propylene carbonate; And a combination thereof (mixed solvent). Among these solvents, an amide solvent or a lactone solvent is preferable, and a solvent containing dimethylacetamide is more preferable. The polyamide imide varnish may contain water, an alcohol solvent, a ketone solvent, a noncyclic ester solvent, an ether solvent, or the like. The resin composition of the present invention may contain an additive that can be included in the above-described film of the present invention.

Next, the polyamide-imide resin A contained in the film of the present invention and the polyamide-imide resin contained in the resin composition of the present invention will be described below. The polyamideimide resins A and B can be obtained by, for example, using the above-mentioned dicarboxylic acid, diamine and tetracarboxylic acid as main raw materials and further copolymerizing them with the above-described tricarboxylic acid Polycondensation).

The polyamide-imide resin A contained in the film of the present invention and the method for producing the polyamide-imide resin B contained in the resin composition of the present invention are not particularly limited as long as the polyamide-imide resin having the above properties can be obtained, ,

(1) a step of copolymerizing a diamine, a dicarboxylic acid, and a tetracarboxylic acid dianhydride in a solvent to obtain a polyamideimide resin precursor, and

(2) a step of adding a dehydrating agent and a tertiary amine to a solution containing at least a polyamideimide resin precursor and heating at a temperature of 70 to 120 캜

And at least a method for producing the same.

According to the present invention,

(1) a step of copolymerizing a diamine, a dicarboxylic acid, and a tetracarboxylic acid dianhydride in a solvent to obtain a polyamideimide resin precursor, and

(2) a step of adding a dehydrating agent and a tertiary amine to a solution containing at least a polyamideimide resin precursor and heating at a temperature of 70 to 120 캜

(2) where w (ppm) is the water content in the solvent at the time of starting the process (1) and t (min) is the heating time in the process (2) The present invention also provides a process for producing a polyamideimide resin.

&Quot; (3) "

The polyamide-imide resin obtained by the production method of the present invention may be, for example, a polyamide-imide resin A or a polyamide-imide resin B, and the polyamide-imide resin A and the polyamide- Are equally suited. It is also possible to obtain the resin composition of the present invention by the production method of the present invention and to produce the film of the present invention by using the resin composition.

In this aspect, the polyamide-imide resin obtained by the production method of the present invention and the polyamide-imide resin B contained in the resin composition of the present invention are the same resin. The polyamide-imide resin B contained in the resin composition of the present invention and the polyamide-imide resin A contained in the film of the present invention may be the same resin in the imidization ratio and the constitutional unit of the resin, And may be different resins.

In the above step (1), diamine, dicarboxylic acid, and tetracarboxylic acid dianhydride are copolymerized in a solvent to obtain a polyamideimide resin precursor. The reaction temperature at the time of copolymerization is not particularly limited, but is, for example, from 50 to 350 캜. The reaction time is not particularly limited, but is, for example, about 30 minutes to 10 hours. If necessary, the reaction may be carried out under an inert atmosphere or under reduced pressure. As the solvent to be used in the step (1), for example, a solvent included in the above-mentioned resin composition of the present invention may be mentioned.

In the step (1), an imidation catalyst may be used. Examples of imidization catalysts include aliphatic amines such as tripropylamine, dibutylpropylamine and ethyldibutylamine; Alicyclic amines (monocyclic) such as N-ethylpiperidine, N-propylpiperidine, N-butylpyrrolidine, N-butylpiperidine, and N-propylhexahydroazepine; Alicyclic amines such as azabicyclo [2.2.1] heptane, azabicyclo [3.2.1] octane, azabicyclo [2.2.2] octane, and azabicyclo [3.2.2] nonane; And pyridine, 2-methylpyridine, 3-methylpyridine, 4-methylpyridine, 2-ethylpyridine, 3-ethylpyridine, 4-ethylpyridine, , 4-cyclopentenopyridine, 5,6,7,8-tetrahydroisoquinoline, and isoquinoline.

Next, in the step (2), a dehydrating agent and a tertiary amine are added to a solution containing at least a polyamideimide resin precursor and heated at a temperature of 70 to 120 캜. In this step, imidization of the polyamideimide resin precursor proceeds. The heating time of the process may be appropriately selected depending on the type and amount of the reaction scale and the reagent to be used, and is usually 1 to 48 hours. From the viewpoint that the degree of yellowness is finally reduced and a polyamideimide film having a high surface hardness can be easily obtained, the imidization rate of the polyamideimide resin contained in the polyamideimide resin composition is preferably 60 (2) may be carried out until the temperature becomes equal to or higher than 80%, more preferably equal to or higher than 80%, and even more preferably equal to or higher than 95%.

The dehydrating agent used in the step (2) is a substance capable of promoting copolymerization in a solvent of diamine, dicarboxylic acid, and tetracarboxylic dianhydride, which are polycondensation reactions accompanied by dehydration. Examples of the dehydrating agent include acetic anhydride, propionic anhydride, isobutyric anhydride, pivalic anhydride, butyric anhydride, and isovaleric acid anhydride. The dehydrating agent is preferably selected from the group consisting of acetic anhydride and propionic anhydride, more preferably acetic anhydride.

The tertiary amine used in the step (2) is a substance acting as an imidation catalyst. Examples of the tertiary amine include, for example, the aforementioned aromatic amines and aliphatic amines. The tertiary amine is preferably selected from the group consisting of triethylamine, tripropylamine, N-ethylpiperidine, N-propylpiperidine, pyridine, methylpyridine, ethylpyridine, dimethylpyridine and isoquinoline.

In the production method of the present invention, when the amount of water in the solvent at the time of starting the step (1) is w (ppm) and the heating time in the step (2) is t .

&Quot; (4) "

1 / t (w + 167) is preferably 5.0 or less, more preferably 4.0 or less, and still more preferably 3.0 or less. Copolymerization of a diamine, a dicarboxylic acid, and a tetracarboxylic acid dianhydride for producing a polyamideimide resin in a solvent is a polycondensation reaction accompanied by dehydration. Therefore, by reducing the amount of water present in the reaction system or adjusting the heating time, the polycondensation reaction (particularly the imidization reaction) can be efficiently advanced, and as a result, the imide It is possible to increase the rate. Therefore, according to the production method of the present invention, it is possible to produce a polyamide-imide resin having a higher imidization ratio than the conventional method. Further, in the conventionally known production method, it is difficult to sufficiently increase the imidization rate of the polyamide-imide resin. Therefore, a process for producing a film using a polyamideimide varnish containing a polyamide-imide resin having a relatively low imidization ratio, and heating the film under a high-temperature condition to progress the imidization process has been carried out. However, as described above, when the imidization rate is increased by heating in the film state, a sufficiently high imidation rate can not be achieved, sufficient surface hardness can not be obtained, and poly The imidization ratio of the amide imide resin is varied, and the imidization ratio is not stabilized. According to the production method of the present invention, the imidization rate of the polyamide-imide resin can be sufficiently increased in the synthesis step before processing into a film, and the above-mentioned problem is solved.

The production method of the present invention is not particularly limited as far as it includes at least the step (1) and the step (2). As a method for producing the resin composition comprising the polyamide-imide resin obtained by the production method of the present invention, for example, a method in which a mixed solution containing the polyamide-imide resin obtained in the step (1) and the step (2) (Hereinafter also referred to as " polyamideimide varnish ") containing at least a polyamide-imide resin and a solvent may be produced by adding a solvent, The polyamideimide resin was precipitated by a reprecipitation method by adding a poor solvent to the mixed solution containing the polyamide-imide resin obtained in 2), dried and taken out as a precipitate, the precipitated polyamide-imide resin was dissolved in a solvent, A resin composition containing at least a polyamide-imide resin and a solvent may be obtained.

The film of the present invention is, for example,

(1) a step of coating the support with the polyamide-imide resin composition thus obtained, and

(2-1) a step of peeling the coating film of the composition from the support after drying,

(2-2) a step of peeling the coating film of the composition from the support after drying, and a step of heating the peeled film

And at least a method for producing the same. Thus, the film of the present invention is formed by drying the coating film of the polyamide-imide resin composition thus obtained.

For example, a coating film of polyamideimide varnish can be formed by coating a polyamideimide varnish on a support such as a resin substrate, an SUS belt, or a glass substrate by a known roll-to-roll or batch method . Examples of the support include a PET film, a PEN film, a polyimide film, and a polyamideimide film. Among them, a PET film, a PEN film, a polyimide film, and other polyamideimide films are preferable from the viewpoint of excellent heat resistance. From the viewpoint of adhesion with the film of the present invention and cost, a PET film is more preferable.

Next, the coating film of the polyamideimide varnish is dried in the step (2-1) or the step (2-2), and is peeled from the support after drying. The coating film can be dried at a temperature of preferably 50 to 240 캜, more preferably 200 to 240 캜. If necessary, the coating film may be dried under an inert atmosphere or under reduced pressure. After drying, the coating film is peeled from the support to obtain the film of the present invention. Further, as described in the step (2-2), for example, a step of further heating the peeled film may be performed in order to further increase the surface hardness (pencil hardness) of the film of the present invention. The heating temperature is preferably 240 占 폚 or lower.

At least one surface of the film produced as described above may be subjected to a surface treatment step of performing surface treatment. The surface treatment includes, for example, UV ozone treatment, plasma treatment and corona discharge treatment.

In a preferred embodiment of the present invention wherein the film of the present invention comprises additives such as additives having a light absorbing function, when the film of the present invention contains the polyamideimide resin and the additive in the same layer, , A polyamideimide resin, and a solvent (polyamide imide varnish) containing at least a polyamideimide resin and a solvent, in addition to the above-mentioned polyamide imide varnish. It is preferable to use an additive having a thermal decomposition temperature of at least 200 캜 or more in a preferred embodiment of the present invention in which an additive such as an additive having a light absorbing function and a polyamideimide resin are contained in one layer.

The film of the present invention may further comprise a functional layer. Examples of the functional layer include layers having various functions such as a hard coating layer, an ultraviolet absorbing layer, a pressure-sensitive adhesive layer, a refractive index-adjusting layer, and a primer layer. The film of the present invention may have one or more functional layers. Further, one functional layer may have a plurality of functions.

The hard coat layer is preferably disposed on the visible side surface of the film. The hard coating layer may have a single-layer structure or a multi-layer structure. The hard coat layer comprises a hard coat layer resin, and examples of the hard coat layer resin include ultraviolet rays such as ultraviolet rays such as an acrylic resin, an epoxy resin, a urethane resin, a benzyl chloride resin, a vinyl resin or a silicone resin, A curing type, an electron beam curing type or a thermosetting type resin. In particular, the hard coat layer preferably comprises an acrylic resin in terms of mechanical properties such as surface hardness and industrial viewpoint. Further, in a preferred embodiment of the present invention, the film of the present invention has a surface hardness sufficient for use in an image display device or the like even if it does not have a hard coat layer, because it has a high surface hardness. Therefore, when the film of the present invention further has a hard coat layer, it is possible to further increase the surface hardness of the film.

The ultraviolet absorbing layer is a layer having a function of absorbing ultraviolet rays and is composed of, for example, a base material (main material) selected from a transparent resin of ultraviolet curing type, a transparent resin of electron beam curing type and a thermosetting type transparent resin, It is composed of ultraviolet absorber. By providing an ultraviolet absorbing layer as a functional layer, the change in yellowness due to light irradiation can be easily suppressed.

The adhesive layer is a layer having a tacky function and has a function of bonding the film of the present invention to other members. As the material for forming the adhesive layer, generally known ones can be used. For example, a thermosetting resin composition or a photo-curable resin composition can be used.

The adhesive layer may be composed of a resin composition containing a component having a polymerizable functional group. In this case, strong adhesion can be realized by further polymerizing the resin composition constituting the adhesive layer after the film is brought into close contact with the other members. The adhesive strength between the film of the present invention and the adhesive layer may be 0.1 N / cm or more, or 0.5 N / cm or more.

The adhesive layer may contain a thermosetting resin composition or a photocurable resin composition as a material. In this case, the resin composition can be polymerized and cured by supplying energy afterwards.

The adhesive layer may be a layer composed of an adhesive which is adhered to an object by pressing, which is called a pressure sensitive adhesive (PSA). The pressure-sensitive adhesive may be a pressure-sensitive adhesive which is "a substance which is tacky at room temperature and adheres to the adherend by light pressure" (JIS K6800), "a specific component is contained in a protective film (microcapsule) (JIS K6800) which can maintain stability until the film is destroyed by means (pressure, heat, etc.) "(JIS K6800).

The color adjustment layer is a layer having a function of color adjustment and is a layer which can adjust the film of the present invention to a desired color. The color adjusting layer is, for example, a layer containing a resin and a coloring agent. Examples of the colorant include inorganic pigments such as titanium oxide, zinc oxide, spinach, titanium oxide-based fired pigment, starch, cobalt aluminate, and carbon black; An organic pigment such as an azo compound, a quinacridone compound, an anthraquinone compound, a perylene compound, an isoindolinone compound, a phthalocyanine compound, a quinophthalone compound, a threne compound, and a diketopyrrolopyrrole compound; Extender pigments such as barium sulfate, and calcium carbonate; And dyes such as basic dyes, acid dyes, and mordant dyes.

The refractive index adjustment layer is a layer having a function of adjusting the refractive index and has a refractive index different from that of the layer containing the polyamideimide resin A in the film of the present invention and is capable of imparting a predetermined refractive index to the film of the present invention to be. The refractive index adjusting layer may be, for example, a suitably selected resin, and optionally, a resin layer containing a pigment, or may be a thin film of a metal.

Examples of pigments for adjusting the refractive index include silicon oxide, aluminum oxide, antimony oxide, tin oxide, titanium oxide, zirconium oxide and tantalum oxide. The average primary particle diameter of the pigment may be 0.1 占 퐉 or less. By setting the average primary particle size of the pigment to be not more than 0.1 mu m, irregular reflection of light transmitted through the refractive index adjustment layer can be prevented, and reduction in transparency can be prevented.

Examples of the metal used for the refractive index adjustment layer include metal oxides such as titanium oxide, tantalum oxide, zirconium oxide, zinc oxide, tin oxide, silicon oxide, indium oxide, titanium oxynitride, titanium nitride, silicon oxynitride, Nitrides.

The film of the present invention is, for example, an optical film useful as a front plate of an image display apparatus, in particular, a front plate (window film) of a flexible display. The film of the present invention can be arranged as a front plate on the visual side surface of an image display apparatus, in particular, a flexible display. This front plate has a function of protecting image display elements in the flexible display.

Examples of the image display device include a wearable device such as a television, a smart phone, a mobile phone, a car navigation system, a tablet PC, a portable game machine, an electronic paper, an indicator, a bulletin board, a clock and a smart watch. As the flexible display, there can be mentioned the above-mentioned image display device having a flexible characteristic.

[Example]

Hereinafter, the present invention will be described in more detail by examples. In the examples, "% " and " part " mean parts by mass and parts by mass, respectively, unless otherwise specified. First, the evaluation method will be described.

≪ Measurement of weight average molecular weight (Mw)

The weight average molecular weight (Mw) of the polyamideimide resin was determined by gel permeation chromatography (GPC) measurement in terms of standard polystyrene. Specific measurement conditions are as follows.

(1) Pretreatment method

DMF eluant (10 mM lithium bromide solution) was added to the obtained polyamideimide resin so as to have a concentration of 2 mg / mL, and the mixture was heated with stirring at 80 캜 for 30 minutes. After cooling, filtration was performed using a membrane filter having a pore size of 0.45 탆 The resulting solution was used as a measurement solution.

(2) Measurement conditions

Column: TSKgel SuperAWM-H x 2 + SuperAW 2500 x 1 (6.0 mm ID x 150 mm x 3)

(All manufactured by TOSOH CORPORATION)

Eluent: DMF (10 mM lithium bromide added)

Flow rate: 1.0 mL / min.

Detector: RI detector

Column temperature: 40 ° C

Injection volume: 100 μL

Molecular weight standard: Standard polystyrene

≪ Measurement of Glass Transition Temperature (Tg) >

Using DMA Q800 manufactured by TA Instrument, the measurement was carried out under the following samples and conditions to obtain a tan delta curve which is the ratio of the loss elastic modulus and the storage elastic modulus. From the peak of the peak of the tan? curve, Tg of the polyamide-imide resin was calculated.

Sample (film): length 5-15 mm, width 5 mm

Experimental mode: DMA Multi-Frequency-Strain

Experiment mode Detailed condition:

(1) Clamp: Tension: Film

(2) Amplitude: 5 탆

(3) Frequncy: 10 Hz (no change over the entire temperature range)

(4) Preload Force: 0.01 N

(5) Force Track: 125 N

Temperature conditions: (1) Temperature rise range: normal temperature to 400 ° C, (2) temperature rise rate: 5 ° C / minute

Main collection data: (1) Storage modulus, E ', (2) Loss modulus, E', and (3)

≪ Measurement of imidization rate &

The imidization ratios of the polyimide resin and the polyamideimide resin used in Examples and Comparative Examples were measured by NMR and calculated using a signal derived from the partial structure shown in Formula (10). A method of calculating the imidization rate from the measurement conditions and the obtained results is as follows.

(34)

(Method of preparing measurement sample)

Polyamideimide resin B:

A resin obtained by adding an excess amount of methanol to a resin composition (varnish) containing at least a solvent and precipitating and drying by a reprecipitation method was dissolved in dehydrated dimethyl sulfoxide (DMSO-d6) to prepare 2 mass% Solution was used as a measurement sample.

Polyamideimide resin A:

The film containing the resin was dissolved in deuterated dimethyl sulfoxide (DMSO-d6) to give a 2 mass% solution, which was used as a measurement sample.

(Measurement conditions of NMR)

Measuring apparatus: 600MHz NMR apparatus AVANCE600 manufactured by Bruker

Sample temperature: 303 K

Measuring method: 1H-NMR, HSQC

(A method of calculating the imidization ratio of the polyimide resin)

In the ¹ H-NMR spectrum obtained in a solution containing the polyimide resin as a measurement sample, a signal derived from the integral of a signal derived from the proton (A) of formula (10) in Int _A, proton (B) The integral value is called Int _B. From these values, the imidization ratio (%) was determined by the following equation (NMR-1).

&Quot; (5) "

(A method of calculating the imidization ratio of the polyamide-imide resin)

The integral value of the signal derived from the proton (C) in the formula (10XXX) is represented by Int _C , the proton (D) and the proton (E) in the HSQC spectrum obtained by using the solution containing the polyimide resin as a measurement sample The average value of the integral of the signal is referred to as Int _DE . From these values, beta values were obtained by the following formula (NMR-2).

&Quot; (6) "

Next, the β value by the formula (NMR-2) and the imidization ratio (%) by the formula (NMR-1) were determined for a plurality of polyimide resins, ).

&Quot; (7) "

Then, in the HSQC spectrum obtained by using the solution containing the polyamide-imide resin as a measurement sample, the? Value was obtained by the formula (NMR-2) in the same manner as described above. By substituting this value for the above correlation (NMR-3), the imidization ratio (%) of the polyamideimide resin was obtained.

≪ Measurement of total light transmittance (Tt) >

The total light transmittance Tt of the obtained polyamide-imide film was measured by Hayato Computer, Ltd., HGM-2DP, fully automated, manufactured by Suga Test Instruments Co., Ltd., in accordance with JIS K7105: 1981.

≪ Measurement of yellowness value (YI value) >

The yellow index (YI value) of the obtained polyamide-imide film was measured using an ultraviolet visible near infrared spectrophotometer V-670 manufactured by Nippon Bunko K. K., in accordance with JIS K 7373: 2006. After the background measurement in the absence of the sample, the sample was set in the sample holder, and the transmittance was measured with respect to the light of 300 to 800 nm to obtain the three-pole value (X, Y, Z). The YI value was calculated based on the following equation.

&Quot; (8) "

<Measurement of surface hardness>

The pencil hardness of the sample surface was measured in accordance with JIS K5600-5-4: 1999 as the surface hardness of the obtained polyamideimide film. Under the conditions of a load of 100 g and a scanning speed of 60 mm / min under the condition of light intensity of 4000 lux to evaluate the presence or absence of scratches, and the pencil hardness was determined.

&Lt; Measurement of elastic modulus &

The modulus of elasticity of the obtained polyamide-imide film was measured using Autograph AG-IS manufactured by Shimadzu Corporation. A S-S curve was measured under the conditions of a chuck distance of 500 mm and a tensile speed of 20 mm / min using a film cut into a 10 mm width, and the elastic modulus was calculated from the slope.

&Lt; Measurement of flex resistance &

As the bending resistance of the obtained polyamide-imide film, the number of reciprocating bending was measured using an MIT internal fatigue tester (Model 0530) manufactured by Toyo Seiki Kogyo Co., Ltd. The number of reciprocating bending until the film was broken was measured under the conditions of R = 1 mm, 135 DEG, a weight of 0.75 kgf, and a speed of 175 cpm, using a film cut into a thickness of 50 mu m and a width of 10 mm.

[Example 1]

52 g (162.38 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and N, N (trimethylsilyl) benzene having a water content adjusted to 500 ppm were placed in a 1 L separable flask equipped with a stirrer under a nitrogen atmosphere. -Dimethylacetamide (DMAc) was added and the TFMB was dissolved in DMAc with stirring at room temperature. Next, 28.90 g (65.05 mmol) of 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) and 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) (9.57 g, 32.52 mmol), and the mixture was stirred at room temperature for 3 hours. Thereafter, 13.21 g (63.10 mmol) of terephthaloyl chloride (TPC) was added to the flask and stirred at room temperature for 1 hour. Then, 4.99 g (63.10 mmol) of pyridine and 21.91 g (214.66 mmol) of acetic anhydride were added to the flask, and the mixture was stirred at room temperature for 30 minutes, then heated to 70 DEG C using an oil bath, To obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, put into a large amount of methanol in a form of a yarn, and precipitated precipitates were taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyamideimide resin.

DMAc was added to the obtained polyamide-imide resin so as to have a concentration of 15 mass% to prepare a polyamideimide varnish. The obtained polyamideimide varnish was coated on a smooth surface of a polyester substrate (trade name &quot; A4100 &quot;, manufactured by TOYOBO CO., LTD.) Using an applicator so as to have a self-supporting film thickness of 55 mu m, C for 15 minutes to obtain a free standing film (free standing film). The self-standing membrane was fixed to a metal frame and further dried at 300 캜 for 30 minutes under the atmosphere to obtain a polyamideimide film having a thickness of 50 탆.

[Example 2]

A polyamideimide film was produced in the same manner as in Example 1 except that the water content of DMAc in Example 1 was changed to 100 ppm and the heating time after heating at 70 ° C was changed to 1 hour to obtain a polyamideimide resin .

[Example 3]

52 g (162.38 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and N, N (trimethylsilyl) benzene having a water content adjusted to 500 ppm were placed in a 1 L separable flask equipped with a stirrer under a nitrogen atmosphere. 657.63 g of dimethylacetamide (DMAc) was added and the TFMB was dissolved in DMAc with stirring at room temperature. Subsequently, 21.67 g (48.79 mmol) of 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) and 3,3', 4,4'-biphenyltetracarboxylic dianhydride BPDA) (4.78 g, 16.26 mmol), and the mixture was stirred at room temperature for 3 hours. Thereafter, 19.81 g (97.57 mmol) of terephthaloyl chloride (TPC) was added to the flask, and the mixture was stirred at room temperature for 1 hour. Next, 7.49 g (94.65 mmol) of pyridine and 14.61 g (143.11 mmol) of acetic anhydride were added to the flask, stirred for 30 minutes at room temperature, then heated to 70 DEG C using an oil bath, Followed by stirring to obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, put into a large amount of methanol in a form of a yarn, and precipitated precipitates were taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyamideimide resin.

DMAc was added to the obtained polyamide-imide resin so that the concentration became 15 mass%, thereby preparing a polyamideimide varnish. The obtained polyamideimide varnish was coated on a smooth surface of a polyester substrate (trade name &quot; A4100 &quot;, manufactured by TOYOBO CO., LTD.) Using an applicator so as to have a self-supporting film thickness of 55 mu m, Lt; 0 &gt; C for 15 minutes to obtain a self-supporting film. The self-standing membrane was fixed to a metal frame and further dried at 300 캜 for 30 minutes under the atmosphere to obtain a polyamideimide film having a thickness of 50 탆.

[Example 4]

52 g (162.38 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and N, N (trimethylsilyl) benzene having a water content adjusted to 500 ppm were placed in a 1 L separable flask equipped with a stirrer under a nitrogen atmosphere. 673.93 g of dimethylacetamide (DMAc) was added and TFMB was dissolved in DMAc with stirring at room temperature. Then, 28.90 g (65.05 mmol) of 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) was added to the flask, and the mixture was stirred at room temperature for 3 hours. Then, 19.81 g (97.57 mmol) of terephthaloyl chloride (TPC) was added to the flask and stirred at room temperature for 1 hour. Then, 7.49 g (94.65 mmol) of pyridine and 14.61 g (143.11 mmol) of acetic anhydride were added to the flask, and the mixture was stirred at room temperature for 30 minutes, then heated to 70 DEG C using an oil bath and further stirred for 5 hours To obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, put into a large amount of methanol in a form of a yarn, and precipitated precipitates were taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyamideimide resin.

DMAc was added to the obtained polyamide-imide resin so that the concentration became 15 mass%, thereby preparing a polyamideimide varnish. The obtained polyamideimide varnish was coated on a smooth surface of a polyester substrate (trade name &quot; A4100 &quot;, manufactured by TOYOBO CO., LTD.) Using an applicator so as to have a self-supporting film thickness of 55 mu m, Lt; 0 &gt; C for 15 minutes to obtain a self-supporting film. The self-standing membrane was fixed to a metal frame and further dried at 230 캜 for 30 minutes under the atmosphere to obtain a polyamideimide film having a thickness of 50 탆.

[Example 5]

52 g (162.38 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and N, N (trimethylsilyl) benzene having a water content adjusted to 500 ppm were placed in a 1 L separable flask equipped with a stirrer under a nitrogen atmosphere. -Dimethylacetamide (DMAc) was added and TFMB was dissolved in DMAc with stirring at room temperature. Then, 28.90 g (65.05 mmol) of 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) was added to the flask, and the mixture was stirred at room temperature for 3 hours. Thereafter, 28.80 g (97.57 mmol) of 4,4'-oxybis (benzoyl chloride) (OBBC) was added to the flask and stirred at room temperature for 1 hour. Then, 7.49 g (94.65 mmol) of pyridine and 14.61 g (143.11 mmol) of acetic anhydride were added to the flask, and the mixture was stirred at room temperature for 30 minutes, then heated to 70 DEG C using an oil bath and further stirred for 5 hours To obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, put into a large amount of methanol in a form of a yarn, and precipitated precipitates were taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyamideimide resin.

DMAc was added to the obtained polyamide-imide resin so that the concentration became 15 mass%, thereby preparing a polyamideimide varnish. The obtained polyamideimide varnish was coated on a smooth surface of a polyester substrate (trade name &quot; A4100 &quot;, manufactured by TOYOBO CO., LTD.) Using an applicator so as to have a self-supporting film thickness of 55 mu m, Lt; 0 &gt; C for 15 minutes to obtain a self-supporting film. The self-standing membrane was fixed to a metal frame and further dried at 300 캜 for 30 minutes under the atmosphere to obtain a polyamideimide film having a thickness of 50 탆.

[Example 6]

52 g (162.38 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and N, N (trimethylsilyl) benzene having a water content adjusted to 500 ppm were placed in a 1 L separable flask equipped with a stirrer under a nitrogen atmosphere. -Dimethylacetamide (DMAc) was added and TFMB was dissolved in DMAc with stirring at room temperature. Then, 28.90 g (65.05 mmol) of 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) was added to the flask, and the mixture was stirred at room temperature for 3 hours. Thereafter, 28.80 g (97.57 mmol) of 4,4'-oxybis (benzoyl chloride) (OBBC) was added to the flask and stirred at room temperature for 1 hour. Then, 7.49 g (94.65 mmol) of pyridine and 26.56 g (260.2 mmol) of acetic anhydride were added to the flask, and the mixture was stirred at room temperature for 30 minutes, then heated to 70 DEG C using an oil bath and further stirred for 5 hours To obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, put into a large amount of methanol in a form of a yarn, and precipitated precipitates were taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyamideimide resin.

DMAc was added to the obtained polyamide-imide resin so that the concentration became 15 mass%, thereby preparing a polyamideimide varnish. The obtained polyamideimide varnish was coated on a smooth surface of a polyester substrate (trade name &quot; A4100 &quot;, manufactured by TOYOBO CO., LTD.) Using an applicator so as to have a self-supporting film thickness of 55 mu m, Lt; 0 &gt; C for 15 minutes to obtain a self-supporting film. The self-standing membrane was fixed to a metal frame and further dried at 300 캜 for 30 minutes under the atmosphere to obtain a polyamideimide film having a thickness of 50 탆.

[Example 7]

52 g (162.38 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and N, N (trimethylsilyl) benzene having a water content adjusted to 500 ppm were placed in a 1 L separable flask equipped with a stirrer under a nitrogen atmosphere. 667.75 g of dimethylacetamide (DMAc) was added and TFMB was dissolved in DMAc with stirring at room temperature. Next, 21.67 g (48.79 mmols) of terephthaloyl chloride (TPC) 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) was added to the flask and stirred at room temperature for 3 hours. Thereafter, 9.60 g (32.52 mmol) of 4,4'-oxybis (benzoyl chloride) (OBBC) and 16.51 g (81.31 mmol) of terephthaloyl chloride (TPC) were added to the flask and stirred at room temperature for 1 hour Respectively. Then, 8.73 g (110.42 mmol) of pyridine and 10.96 g (107.33 mmol) of acetic anhydride were added to the flask, and the mixture was stirred at room temperature for 30 minutes, then heated to 70 DEG C using an oil bath, To obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, put into a large amount of methanol in a form of a yarn, and precipitated precipitates were taken out, immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyamideimide resin.

DMAc was added to the obtained polyamide-imide resin so that the concentration became 15 mass%, thereby preparing a polyamideimide varnish. The obtained polyamideimide varnish was coated on a smooth surface of a polyester substrate (trade name &quot; A4100 &quot;, manufactured by TOYOBO CO., LTD.) Using an applicator so as to have a self-supporting film thickness of 55 mu m, Lt; 0 &gt; C for 15 minutes to obtain a self-supporting film. The self-standing membrane was fixed to a metal frame and further dried at 300 캜 for 30 minutes under the atmosphere to obtain a polyamideimide film having a thickness of 50 탆.

[Comparative Example 1]

A polyamideimide film was obtained in the same manner as in Example 1, except that the stirring time after heating at 70 캜 was changed to 1 hour in Example 1 to obtain a polyamideimide resin.

[Comparative Example 2]

A polyamideimide film was obtained in the same manner as in Example 3 except that the stirring time after heating at 70 ° C in Example 3 was changed to 1 hour to obtain a polyamideimide resin.

[Comparative Example 3]

52 g (162.38 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and N, N (trimethylsilyl) benzene having a water content adjusted to 500 ppm were placed in a 1 L separable flask equipped with a stirrer under a nitrogen atmosphere. -Dimethylacetamide (DMAc) was added and TFMB was dissolved in DMAc with stirring at room temperature. Next, 72.24 g (162.62 mmol) of 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) was added to the flask and stirred at room temperature for 3 hours. Then, 6.43 g (81.31 mmol) of pyridine and 36.52 g (357.77 mmol) of acetic anhydride were added to the flask, and the mixture was stirred at room temperature for 30 minutes, then heated to 70 DEG C using an oil bath, To obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, put into a large amount of methanol in a form of a yarn, and precipitated precipitates were taken out, immersed in methanol for 6 hours, and then washed with methanol. Subsequently, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyimide resin.

DMAc was added to the obtained polyimide resin so that the concentration became 15 mass% to prepare a polyimide varnish. The obtained polyimide varnish was coated on a smooth surface of a polyester substrate (trade name &quot; A4100 &quot;, trade name, manufactured by TYOYAN CO., LTD.) Using an applicator so as to have a self-supporting film thickness of 55 μm, And dried for 15 minutes to obtain a self-supporting film. The free-standing film was fixed to a metal frame and further dried at 300 캜 for 30 minutes under the atmosphere to obtain a polyimide film having a thickness of 50 탆.

[Comparative Example 4]

52 g (162.38 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and N, N (trimethylsilyl) benzene having a water content adjusted to 500 ppm were placed in a 1 L separable flask equipped with a stirrer under a nitrogen atmosphere. 733.51 g of dimethylacetamide (DMAc) was added and the TFMB was dissolved in DMAc with stirring at room temperature. Next, 28.90 g (65.05 mmol) of 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) and 3,3', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) (28.71 g, 97.57 mmol), and the mixture was stirred at room temperature for 3 hours. Then, 6.43 g (81.31 mmol) of pyridine and 36.52 g (357.77 mmol) of acetic anhydride were added to the flask, and the mixture was stirred at room temperature for 30 minutes, then heated to 70 DEG C using an oil bath, To obtain a reaction solution.

The obtained reaction solution was cooled to room temperature, put into a large amount of methanol in a form of a yarn, and precipitated precipitates were taken out, immersed in methanol for 6 hours, and then washed with methanol. Subsequently, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyimide resin.

DMAc was added to the obtained polyimide resin so that the concentration became 15 mass% to prepare a polyimide varnish. The obtained polyimide varnish was coated on a smooth surface of a polyester substrate (trade name &quot; A4100 &quot;, trade name, manufactured by TYOYAN CO., LTD.) Using an applicator so as to have a self-supporting film thickness of 55 μm, And dried for 15 minutes to obtain a self-supporting film. The free-standing film was fixed to a metal frame and further dried at 300 캜 for 30 minutes under the atmosphere to obtain a polyimide film having a thickness of 50 탆.

[Comparative Example 5]

A polyamideimide film was obtained in the same manner as in Example 1 except that the water content of DMAc was changed to 1000 ppm in Example 1 to obtain a polyamideimide resin.

[Comparative Example 6]

A polyamideimide film was obtained in the same manner as in Example 1 except that the polyamideimide resin was obtained by changing the moisture content of DMAc to 1700 ppm and the stirring time after heating at 70 DEG C to 5 hours in Example 1.

[Comparative Example 7]

A polyamideimide film was obtained in the same manner as in Example 5 except that the stirring time after heating at 70 ° C in Example 5 was changed to 30 minutes to obtain a polyamideimide resin.

[Comparative Example 8]

A polyamideimide film was obtained in the same manner as in Example 7 except that the stirring time after heating at 70 ° C in Example 7 was changed to 30 minutes to obtain a polyamideimide resin.

[Example 8]

45 g (140.5 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and 20 g of N, N (N, N'-dicyclohexylmethane) having a water content of 200 ppm were added to a 1 L separable flask equipped with a stirring wing under a nitrogen gas atmosphere. -Dimethylacetamide (DMAc) was added and the TFMB was dissolved in DMAc with stirring at room temperature. Next, 4.14 g (14.1 mmol) of 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride (BPDA) was added to the flask, and after stirring at room temperature for 2.5 hours, 4,4' - Hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) (25.01 g, 56.3 mmol) was added thereto, and the mixture was stirred at room temperature for 15 hours. In addition, 4.15 g (14.1 mmol) of 4,4'-oxybis (benzoyl chloride) (OBBC) and 11.43 g (56.3 mmol) of terephthaloyl chloride (TPC) were added to the flask and stirred at room temperature for 1 hour Respectively. Then, 21.55 g (211.1 mmol) of acetic anhydride and 3.28 g (35.2 mmol) of 4-picoline were added to the flask, and the mixture was stirred at room temperature for 30 minutes. Thereafter, the mixture was heated to 70 DEG C using an oil bath, And stirred for a time to obtain a reaction solution.

After the obtained reaction solution was cooled to room temperature, 647 g of methanol and 180 g of ion-exchanged water were added to obtain a precipitate of polyamideimide. It was immersed in methanol for 12 hours, collected by filtration and washed with methanol. Next, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyamideimide resin. The molar ratios of the respective components are shown in Table 1.

DMAc was added to the obtained polyamide-imide resin so that the concentration became 15 mass%, thereby preparing a polyamideimide varnish. The obtained polyamideimide varnish was coated on a smooth surface of a polyester substrate (trade name &quot; A4100 &quot;, manufactured by TOYOBO CO., LTD.) Using an applicator so as to have a self-supporting film thickness of 55 mu m, Lt; 0 &gt; C for 15 minutes to obtain a self-supporting film. The self-standing membrane was fixed to a metal frame and further dried at 300 캜 for 30 minutes under the atmosphere to obtain a polyamideimide film having a thickness of 50 탆.

[Example 9]

(45.8 mmols) of 2,2'-bis (trifluoromethyl) benzidine (TFMB) and N, N (trimethylsilyl) benzyldiimidazole prepared with a water content of 200 ppm were placed in a 1 L separable flask equipped with a stirrer under a nitrogen gas atmosphere, 233.3 g of dimethylacetamide (DMAc) was added and TFMB was dissolved in DMAc with stirring at room temperature. Next, 4.283 g (13.8 mmol) of 4,4'-oxydiphthalic dianhydride (OPDA) was added to the flask, and the mixture was stirred at room temperature for 16.5 hours. Then 1.359 g (4.61 mmol) of 4,4'-oxybis (benzoyl chloride) (OBBC) and 5.609 g (27.6 mmol) of terephthaloyl chloride (TPC) were added to the flask and stirred at room temperature for 1 hour Respectively. Next, 4.937 g (48.35 mmol) of acetic anhydride and 1.501 g (16.12 mmol) of 4-picolin were added to the flask, stirred for 30 minutes at room temperature, and then heated to 70 DEG C using an oil bath. And the mixture was stirred for 3 hours to obtain a reaction solution.

After cooling the reaction solution to room temperature, 360 g of methanol and 170 g of ion-exchanged water were added to obtain a precipitate of polyamideimide. It was immersed in methanol for 12 hours, collected by filtration and washed with methanol. Next, the precipitate was dried under reduced pressure at 100 占 폚 to obtain a polyamideimide resin. The molar ratios of the respective components are shown in Table 1.

In the same manner as in Example 8, a polyamide-imide film having a thickness of 50 탆 was obtained from the polyamide-imide resin obtained in Example 9.

[Example 10]

6.140 g of 4,4 '- (hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA) was used instead of 4.283 g of 4,4'-oxydiphthalic dianhydride (OPDA), and 2,2'- Except that 8.809 g (27.5 mmols) of TFMB and 3.889 g (18.3 mmols) of 2,2'-dimethylbenzidine (MB) were used in place of 14.67 g (45.8 mmols) , A polyamideimide resin was obtained. The molar ratios of the respective components are shown in Table 1.

In the same manner as in Example 8, a polyamide-imide film having a thickness of 50 탆 was obtained from the polyamide-imide resin obtained in Example 10.

[Example 11]

Except that 3.670 g (18.3 mmol) of 4,4'-diaminodiphenyl ether (ODA) was used instead of 3.889 g of 2,2'-dimethylbenzidine (MB) To obtain a resin. The molar ratios of the respective components are shown in Table 1.

In the same manner as in Example 8, a polyamide-imide film having a thickness of 50 탆 was obtained from the polyamide-imide resin obtained in Example 11.

The proportions of respective constituent units and the synthesis conditions in the polyamide-imide resin (B) contained in the polyamideimide varnish obtained in the above example and the resin (B) contained in the varnish obtained in the comparative example are shown in the following Table 1 . Table 1 also shows the results of measurement of the imidization ratio of the polyamide-imide resin (B) and the resin (B) according to the aforementioned measuring method. In Table 1, the imidization rate of the polyamide-imide resin (B) and the resin (B) is referred to as "imidization rate B", the water content in the solvent at the time of starting the process (1) The ratio of the molar amount of the dehydrating agent added in the step (2) to the molar amount of the tetracarboxylic dianhydride added in the step (1) is defined as "t [min]" in the step (2) Added amount &quot;. Here, in the measurement of the imidization rate B of the polyimide resin B obtained in Comparative Examples 3 and 4, a polyimide resin B was prepared in the same manner as the polyamideimide resin B except that the resin was changed.

The imidization ratio of the polyamide-imide resin (A) contained in the polyamide-imide film obtained in the above example and the resin (A) contained in the film obtained in the comparative example was measured according to the measurement method, Shown in Table 2 as &quot; imidization rate A &quot;. Here, in the measurement of the imidization ratio of the polyimide resin A contained in the polyimide film obtained in Comparative Examples 3 and 4, polyimide resin A was prepared in the same manner as the polyamideimide resin A except that the resin was changed Respectively. The films obtained in Examples and Comparative Examples were measured for pencil hardness, yellowness (YI), total light transmittance (Tt), elasticity and bending resistance (number of reciprocating bending) according to the above measuring method. The obtained results are shown in Table 1. The ratios of the proportions of the respective constituent units in the polyamide-imide resin (A) contained in the polyamide-imide film and the resin (A) contained in the film obtained in the comparative example are shown in Table 1 Is the same as the proportion of the constituent units in the polyamideimide resin (B) and the resin (B). In Examples 10 and 11, it was confirmed that signals derived from different structures from repeating units having an amic acid and repeating units having an imide bond were overlapped with each other. Therefore, in the signal, the intensities of the non-overlapping portions were integrated, the original signal intensities were determined from the area ratio of the portions, and the imidization rates A and B were calculated.

Claims (15)

Dimensional amorphous polymer having at least a structural unit derived from a diamine, a structural unit derived from a dicarboxylic acid, and a structural unit derived from a tetracarboxylic dianhydride and having an imidization rate of not less than 95% A film comprising Resin A. The method according to claim 1,
The diamine is represented by the formula (3):
[Chemical Formula 1]

[In the formula (3), X represents a group represented by the formula (3e '):
(2)

Wherein each of R ¹⁰ to R ¹⁷ independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and the hydrogen atom contained in R ¹⁰ to R ¹⁷ , Each independently represents a halogen atom, and * represents a bond).
&Lt; / RTI &gt; 3. The method according to claim 1 or 2,
The dicarboxylic acid is represented by the formula (2):
(3)

(2), Z is a group represented by the formula (2a) or (2b)
[Chemical Formula 4]

Of [formula (2a) and Equation (2b), U 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-, - B ¹ and B ² each independently represent an OH or a halogen atom, or a group represented by the formula: Ar-C (CH ₃ ) ₂ -Ar- or Ar-SO ₂ -Ar- Atom.]
&Lt; / RTI &gt; 4. The method according to any one of claims 1 to 3,
The tetracarboxylic dianhydride is represented by the formula (4):
[Chemical Formula 5]

Wherein Y is a group represented by the formula (4g):
[Chemical Formula 6]

(In the formula (4g), W ¹ represents a single bond, -C (CH ₃ ) ₂ - or C (CF ₃ ) ₂ -, and * represents a bonding bond.
&Lt; / RTI &gt; 5. The method according to any one of claims 1 to 4,
Wherein the polyamide-imide resin A comprises a fluorine atom. 6. The method according to any one of claims 1 to 5,
A film having a YI of 3 or less. 7. The method according to any one of claims 1 to 6,
A film having a pencil hardness of 3B or greater, measured according to ASTM D 3363 under 4000 lux illumination conditions. A polyamideimide resin having a structural unit derived from a diamine, a structural unit derived from a dicarboxylic acid, and a structural unit derived from a tetracarboxylic dianhydride and having an imidization ratio of 60% or more, B, and a solvent. 9. The method of claim 8,
The diamine is represented by the formula (3):
(7)

[In the formula (3), X represents a group represented by the formula (3e '):
[Chemical Formula 8]

Wherein each of R ¹⁰ to R ¹⁷ independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and the hydrogen atom contained in R ¹⁰ to R ¹⁷ , Each independently represents a halogen atom, and * represents a bond.]
At least one kind of compound represented by the following general formula (1). 10. The method according to claim 8 or 9,
The dicarboxylic acid is represented by the formula (2):
[Chemical Formula 9]

(2), Z is a group represented by the formula (2a) or (2b):
[Chemical formula 10]

Of [formula (2a) and Equation (2b), U 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-, - B ¹ and B ² each independently represent an OH or a halogen atom, or a group represented by the formula: Ar-C (CH ₃ ) ₂ -Ar- or Ar-SO ₂ -Ar- Atom.]
At least one kind of compound represented by the following general formula (1). 11. The method according to any one of claims 8 to 10,
The tetracarboxylic dianhydride is represented by the formula (4):
(11)

[In the formula (4), Y represents a group represented by the formula (4g):
[Chemical Formula 12]

(In the formula (4g), W ¹ represents a single bond, -C (CH ₃ ) ₂ - or C (CF ₃ ) ₂ -, and * represents a bonding bond.
At least one kind of compound represented by the following general formula (1). The method according to any one of claims 8 to 11,
And the polyamide-imide resin B comprises a fluorine atom. A film obtained by drying a coating film of the resin composition according to any one of claims 8 to 12. (1) a step of copolymerizing a diamine, a dicarboxylic acid, and a tetracarboxylic acid dianhydride in a solvent to obtain a polyamideimide resin precursor, and
(2) a step of adding a dehydrating agent and a tertiary amine to a solution containing at least a polyamideimide resin precursor and heating at a temperature of 70 to 120 캜
(Ppm) and the heating time in the step (2) is t (minute), the amount of water in the solvent at the time of starting the step (1) , w and t satisfy the following expression:
[Equation 1]

. &Lt; / RTI &gt; 15. The method of claim 14,
Wherein the molar amount of the dehydrating agent added in the step (2) is at least twice the molar amount of the tetracarboxylic acid dianhydride added in the step (1).