KR20190110970A - Laminate - Google Patents

Abstract

The purpose of the present invention is to provide a laminate including a transparent resin film based on a polyimide-based polymer, which is less likely to be whitened on the film surface and has a good appearance and visibility. The laminate comprises: a transparent resin film comprising at least one selected from the group consisting of polyimide, polyamide, and polyamideimide and one or more solvents, and produced using the one or more solvents by a casting method; and a protective film bonded to the surface of at least one side of the transparent resin film, wherein a boiling point of a solvent having the highest boiling point among the one or more solvents is 120 to 300°C. In addition, a residual solvent amount (S) (mass%) of the transparent resin film calculated as a mass reduction rate from 120 to 250°C by thermogravimetric-differential thermal measurement and a low molecular component amount (W) (%) defined as a ratio of an area where log M for the total area of a chart obtained by measuring by a gel permeation chromatography of the protective film at a measurement temperature of 140°C is from 2.82 to 3.32 satisfy a relational expression (1) S × W <= 4.7 (1), wherein W is less than or equal to 0.33.

Description

Laminates {LAMINATE}

The present invention relates to a laminate.

Background Art In recent years, transparent resin films based on polymers such as polyimide and polyamide have been widely used as materials to replace glass, which has been conventionally used with thinning, lightening and flexible display of various image display apparatuses. The casting method (solution casting method) is known as one of the manufacturing methods of such a transparent resin film. In the cast method, a varnish containing a polymer such as polyimide dissolved in a solvent is generally applied onto a supporting substrate to form a film, and then peeled from the supporting substrate, and then the solvent is removed by drying. Thereby, a resin film can be shape | molded continuously. The peelable protective film is laminated | stacked suitably on the surface of the transparent resin film formed into a film, and protection of the film surface is aimed at (patent documents 1-3).

Japanese Patent Laid-Open No. 2010-208312 Japanese Patent Laid-Open No. 2015-214122 Japanese Patent Laid-Open No. 2016-87799

When a solvent exists in a resin film, components, such as an additive contained in a protective film, may elute with the solvent contained in a resin film, and the resin film with which the protective film was bonded by the eluted component. The surface of may whiten. In particular, in the transparent resin film manufactured by using a solvent by the casting method or the like, in the continuous production, it is difficult to completely remove the solvent in the varnish, and a certain amount of the solvent is often left. It is easy to produce whitening when bonded together. The whitening in such a transparent resin film is not only an external defect in a transparent resin film requiring high transparency, but also causes deterioration of visibility when used for displays such as various image display devices.

Then, an object of this invention is to provide the laminated body which consists of a transparent resin film based on the polyimide type polymer which is hard to produce whitening of the film surface, and has favorable external appearance and visibility.

MEANS TO SOLVE THE PROBLEM This inventor came to complete this invention, as a result of earnestly examining in order to solve the said subject. That is, this invention provides the following preferable aspects.

[1] a transparent resin film comprising at least one solvent selected from the group consisting of polyimide, polyamide, and polyamideimide, and at least one solvent; In the laminated body which consists of a protective film bonded to at least one surface of the said transparent resin film,

The boiling point of the solvent with the highest boiling point among the said 1 or more types of solvents is 120-300 degreeC,

Measurement of residual solvent amount (S) (mass%) of the said transparent resin film and the said protective film which are computed as a mass reduction rate in 120 degreeC from 250 degreeC by thermogravimetry-differential heat (TD-DTA) measurement The amount of low molecular weight component (W) (%) defined as a ratio of the area from 2.82 to 3.32 for the log area of the chart obtained by measurement by gel permeation chromatography at a temperature of 140 ° C is represented by the relation (1):

S × W≤4.7 (One)

To satisfy

The laminated body whose W is 0.33 or less.

[2] S and W are relations (1 '):

0.005≤S × W (One')

The laminated body as described in said [1] which satisfy | fills.

[3] The laminate according to the above [1] or [2], wherein the haze of the transparent resin film is 1.0% or less.

[4] The laminate according to any one of [1] to [3], wherein a total light transmittance of the transparent resin film is 85% or more.

[5] The transparent resin film contains at least one solvent selected from the group consisting of N, N-dimethylacetamide, γ-butyrolactone, N-methylpyrrolidone, cyclopentanone, butyl acetate and amyl acetate The laminated body in any one of said [1]-[4] said.

[6] The laminate according to any one of the above [1] to [5], wherein the protective film is a polyolefin resin film.

Advantageous Effects of Invention The present invention can provide a laminate comprising a transparent resin film based on a polyimide-based polymer that hardly occurs whitening of the film surface and has good appearance and visibility.

1 shows the TG-DTA measurement result of the transparent polyimide film produced in Example 1. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail. In addition, the scope of the present invention is not limited to embodiment described here, A various change can be made in the range which does not impair the meaning of this invention.

The laminate of the present invention comprises a transparent resin film and a protective film bonded to at least one surface of the transparent resin film, and the transparent resin film constituting the laminate of the present invention is polyimide or polyamide. And at least one selected from the group consisting of polyamide-imide, and formed of a resin composition containing at least one selected from the group consisting of polyimide, polyamide, and polyamideimide.

In this specification, a polyimide represents the polymer containing the repeating structural unit containing an imide group, and polyamideimide contains both the repeating structural unit containing an imide group, and the repeating structural unit containing an amide group. A polymer is shown and a polyamide shows the polymer containing the repeating structural unit containing an amide group. The polyimide polymer refers to a polymer containing any one or more selected from polyimide and polyamideimide.

The polyimide type polymer which concerns on this embodiment has a repeating structural unit represented by Formula (10). Here, G represents a tetravalent organic group and A represents a divalent organic group. G and / or A may include the repeating structural unit represented by two or more other types of formulas (10). In addition, the repeating structural unit represented by any of Formula (11), Formula (12), and Formula (13) is a polyimide polymer which concerns on this embodiment in the range which does not impair the various physical properties of the transparent resin film obtained. One or more of may be included.

It is preferable from a viewpoint of the strength and transparency of a transparent resin film, if the main structural unit of a polyimide polymer is a repeating structural unit represented by Formula (10). In the polyimide polymer according to the present embodiment, the repeating structural unit represented by the formula (10) is preferably 40 mol% or more with respect to the total repeating structural unit of the polyimide polymer, more preferably Is at least 50 mol%, more preferably at least 70 mol%, particularly preferably at least 90 mol%, even more preferably at least 98 mol%. 100 mol% may be sufficient as the repeating structural unit represented by Formula (10).

[Formula 1]

G and G ¹ each independently represent a tetravalent organic group, and preferably a tetravalent organic group having 4 to 40 carbon atoms. The said organic group may be substituted by the hydrocarbon group or the fluorine-substituted hydrocarbon group, and in that case, carbon number of a hydrocarbon group and a fluorine-substituted hydrocarbon group becomes like this. Preferably it is 1-8. Examples G and G ^1, formula 20, formula 21, formula 22, formula 23, formula 24, formula 25, formula 26, formula 27, formula 28 Or the group represented by Formula (29) and a tetravalent C6 or less chain hydrocarbon group are illustrated. In the formula, * represents a bond, Z 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 the C6-C20 arylene group which may be substituted by the fluorine atom, and a phenylene group is mentioned as a specific example. As from easy to suppress the yellowness index of the transparent resin film obtained point, G and G ^1, and preferably formula (20), Equation 21, Equation 22, Equation 23, Equation 24, Equation ( 25), group represented by Formula (26) or Formula (27) is mentioned.

[Formula 2]

G ² represents a trivalent organic group, and preferably a trivalent organic group having 4 to 40 carbon atoms. The said organic group may be substituted by the hydrocarbon group or the fluorine-substituted hydrocarbon group, and in that case, carbon number of a hydrocarbon group and a fluorine-substituted hydrocarbon group becomes like this. Preferably it is 1-8. Examples of G ^2, Equation 20, Equation 21, Equation 22, Equation 23, Equation 24, Equation 25, Equation 26, Equation 27, and Equation 28 or Equation The group by which any one of the bonds of the group represented by (29) was substituted by the hydrogen atom, and a trivalent C6 or less chain hydrocarbon group are illustrated. The example of Z in a formula is the same as the example of Z in the description about G.

G ³ represents a divalent organic group, and preferably a divalent organic group having 4 to 40 carbon atoms. The said organic group may be substituted by the hydrocarbon group or the fluorine-substituted hydrocarbon group, and in that case, carbon number of a hydrocarbon group and a fluorine-substituted hydrocarbon group becomes like this. Preferably it is 1-8. Examples of G ^3, formula 20, formula 21, formula 22, formula 23, formula 24, formula 25, formula 26, formula 27, formula 28 or formula Among the bonds of the group represented by (29), a group in which two non-adjacent groups are substituted with a hydrogen atom and a divalent chain hydrocarbon group having 6 or less carbon atoms are exemplified. The example of Z in a formula is the same as the example of Z in the technique regarding G.

A, A ¹ , A ² and A ³ all represent a divalent organic group, and preferably a divalent organic group having 4 to 40 carbon atoms. The organic group may be substituted with a hydrocarbon group or a fluorine-substituted hydrocarbon group having 1 to 8 carbon atoms, and in that case, the carbon number of the hydrocarbon group and the fluorine-substituted hydrocarbon group is preferably 1 to 8 groups. As A, A ¹ , A ^2, and A ³ , formulas (30), (31), (32), (33), (34), (35), (36), and (3) 37) or a group represented by formula (38); Groups in which these are substituted with at least one of methyl, fluoro, chloro or trifluoromethyl groups; And a chain hydrocarbon group having 6 or less carbon atoms.

* In the formula represents a bond, Z ¹ , Z ² and Z ³ are each independently a single bond, -O-, -CH _2- , -CH ₂ -CH _2- , -CH (CH ₃ )- , -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -S-, -SO _2- , -CO- or -NR ² . Here, R <^2> represents the C1-C12 hydrocarbon group which may be substituted by the halogen atom. It is preferable that Z <^1> and Z <^2> and Z <^2> and Z <^3> are located in meta position or para position with respect to each ring, respectively.

[Formula 3]

In this invention, the resin composition which forms a transparent resin film may contain polyamide. The polyamide which concerns on this embodiment is a polymer which mainly uses the repeating structural unit represented by Formula (13). Preferred and specific examples of G ³ and A ³ in the polyamide is equal to the preferred embodiments and specific examples of G ³ and A ³ in the polyimide-based polymer. The polyamide may include a repeating structural unit represented by two or more formulas (13) in which G ³ and / or A ³ are different.

The polyimide polymer can be obtained, for example, by polycondensation of a diamine and a tetracarboxylic acid compound (tetracarboxylic acid dianhydride, etc.), for example, JP-A-2006-199945 or JP It can synthesize | combine according to the method described in Unexamined-Japanese-Patent No. 2008-163107. Examples of commercially available products of the polyimide include Neopulim (registered trademark) manufactured by Mitsubishi Gas Chemical Co., Ltd. and KPI-MX300F manufactured by Kawamura Industries Co., Ltd.

As tetracarboxylic acid compound used for the synthesis | combination of a polyimide type polymer, Aromatic tetracarboxylic acid and its anhydride, Preferably, aromatic tetracarboxylic acid compounds, such as the dianhydride; And aliphatic tetracarboxylic acids and anhydrides thereof, and preferably aliphatic tetracarboxylic acid compounds such as their anhydrides. The tetracarboxylic acid compound may be a tetracarboxylic acid compound derivative such as a tetracarboxylic acid chloride compound in addition to the anhydride, and these may be used alone or in combination of two or more thereof.

As a specific example of aromatic tetracarboxylic dianhydride, non-condensed polycyclic aromatic tetracarboxylic dianhydride, monocyclic aromatic tetracarboxylic dianhydride, and condensed polycyclic aromatic tetracarboxylic dianhydride are mentioned. As a non-condensed polycyclic aromatic tetracarboxylic dianhydride, 4,4'- oxydiphthalic acid dianhydride, 3,3 ', 4,4'- benzophenone tetracarboxylic dianhydride, 2,2', 3,3 '-Benzophenonetetracarboxylic acid dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic acid dianhydride, 3,3' , 4,4'-diphenylsulfontetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride 2,2-bis (3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic dianhydride (may be described as 6FDA), 1, 2-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2-bis (3,4-dicarboxyphenyl) ethane 2 Anhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) meth Carbon dianhydride, 4,4 '-(p-phenylenedioxy) diphthalic acid dianhydride, and 4,4'-(m-phenylenedioxy) diphthalic acid dianhydride. As monocyclic aromatic tetracarboxylic dianhydride, 1,2,4,5-benzenetetracarboxylic dianhydride is a condensed polycyclic aromatic tetracarboxylic dianhydride as 2,3,6,7-naphthalene. Tetracarboxylic dianhydride is mentioned.

Among these, 4,4'- oxydiphthalic acid dianhydride, 3,3 ', 4,4'- benzophenone tetracarboxylic acid dianhydride, 2,2', 3,3'- benzophenone tetracarboxylic acid Dianhydride, 3,3 ', 4,4'-biphenyltetracarboxylic acid dianhydride, 2,2', 3,3'-biphenyltetracarboxylic acid dianhydride, 3,3 ', 4,4'-di Phenylsulfontetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, 2,2-bis ( 3,4-dicarboxyphenoxyphenyl) propane dianhydride, 4,4 '-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), 1,2-bis (2,3-dicarboxyphenyl) ethane Dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,2-bis (3,4-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-di Carboxyphenyl) ethane dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride, bis (2,3-dicarboxyphenyl) methane dianhydride, 4,4 '-(p-phenylenedioxy) diphthalic acid 2 Anhydride and 4 And 4,4 '-(m-phenylenedioxy) diphthalic dianhydride, and more preferably 4,4'-oxydiphthalic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic acid. Dianhydride, 2,2 ', 3,3'-biphenyltetracarboxylic dianhydride, 4,4'-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), bis (3,4-dicarboxyl And phenyl) methane dianhydride and 4,4 '-(p-phenylenedioxy) diphthalic acid dianhydride. These can be used individually or in combination of 2 or more types.

As aliphatic tetracarboxylic dianhydride, a cyclic or acyclic aliphatic tetracarboxylic dianhydride is mentioned. A cyclic aliphatic tetracarboxylic dianhydride is tetracarboxylic dianhydride which has an alicyclic hydrocarbon structure, As an example, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, 1,2,3,4- Cycloalkanetetracarboxylic dianhydride, such as cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3, And 5,6-tetracarboxylic dianhydride, dicyclohexyl 3,3 ', 4,4'-tetracarboxylic dianhydride and positional isomers thereof. These can be used individually or in combination of 2 or more types. Specific examples of the acyclic aliphatic tetracarboxylic dianhydride include 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-pentanetetracarboxylic dianhydride, and the like. It can be used in combination of 2 or more type. Moreover, you may use combining cyclic aliphatic tetracarboxylic dianhydride and acyclic aliphatic tetracarboxylic dianhydride.

Among the tetracarboxylic acid compounds, the alicyclic tetracarboxylic dianhydride or the non-condensed polycyclic aromatic tetracarboxylic dianhydride is preferably used from the viewpoint of easily improving the elastic modulus, the flex resistance, and the optical properties of the transparent resin film. Can be. As a more preferable specific example, 3,3 ', 4,4'-biphenyl tetracarboxylic dianhydride, 2,2', 3,3'-biphenyl tetracarboxylic dianhydride, 2,2-bis (3,4 -Dicarboxyphenyl) propane dianhydride, and 4,4 '-(hexafluoroisopropylidene) diphthalic acid dianhydride (6FDA). These can be used individually or in combination of 2 or more types.

In addition to the anhydride of tetracarboxylic acid used for said polyimide synthesis | combination, the polyimide type polymer which concerns on this embodiment is a tetracarboxylic acid and a tricarboxylic acid, in the range which does not impair the various physical properties of the obtained transparent resin film. The compound, the dicarboxylic acid compound, anhydrides thereof and derivatives thereof may be further reacted.

Examples of the tricarboxylic acid compound include aromatic tricarboxylic acid, aliphatic tricarboxylic acid, their acid chloride compounds and acid anhydrides, and these may be used in combination of two or more. Specific examples thereof include anhydrides of 1,2,4-benzenetricarboxylic acid; 2,3,6-naphthalenetricarboxylic acid-2,3- anhydride; Phthalic anhydride and benzoic acid single _{bond, -CH 2 -, -C (CH} 3) 2 -, -C (CF 3) 2 -, -SO 2 - or can be connected to the compound group-phenylene.

As a dicarboxylic acid compound, aromatic dicarboxylic acid, aliphatic dicarboxylic acid, those flexible acid chloride compounds, an acid anhydride, etc. are mentioned, These may use 2 or more types together. Specific examples thereof include terephthalic acid; Isophthalic acid; Naphthalenedicarboxylic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; The dicarboxylic acid compound of the chain hydrocarbon having 8 or less carbon atoms and the two benzoic acid skeletons are -CH _2- , -S-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -O-, -NR ⁹ -, -C (= O) - , -SO 2 - or can be connected to the compound group-phenylene. These can be used individually or in combination of 2 or more types. Here, R <^9> represents the C1-C12 hydrocarbon group which may be substituted by the halogen atom.

As a dicarboxylic acid compound, Preferably, it is terephthalic acid; Isophthalic acid; 4,4'-biphenyldicarboxylic acid; 3,3'-biphenyldicarboxylic acid; And a compound in which two benzoic acid skeletons are linked by a —CH ₂ —, —C (═O) —, —O—, —NR ⁹ —, —SO ₂ — or a phenylene group, more preferably terephthalic acid; 4,4'-biphenyldicarboxylic acid; And two benzoic acid backbones linked by —O—, —NR ⁹ —, —C (═O) — or —SO ₂ —. These can be used individually or in combination of 2 or more types.

The ratio of the tetracarboxylic acid compound to the total of the tetracarboxylic acid compound, the tricarboxylic acid compound, and the dicarboxylic acid compound is preferably 40 mol% or more, more preferably 50 mol% or more, and more preferably Is 70 mol% or more, still more preferably 90 mol% or more, particularly preferably 98 mol% or more.

Aliphatic diamine, aromatic diamine, or mixtures thereof are mentioned as a diamine used for the synthesis | combination of a polyimide type polymer. In addition, in this embodiment, "aromatic diamine" represents the diamine in which an amino group is couple | bonded with the aromatic ring directly, and may contain the aliphatic group or another substituent in a part of the structure. The aromatic ring may be monocyclic or a condensed ring, and examples thereof include, but are not limited to, benzene ring, naphthalene ring, anthracene ring and fluorene ring. Among these, Preferably a benzene ring is mentioned. Moreover, "aliphatic diamine" shows the diamine in which an amino group is couple | bonded with the aliphatic group directly, and may contain the aromatic ring and other substituents in a part of the structure.

Specific examples of aliphatic diamines include acyclic aliphatic diamines such as hexamethylenediamine, 1,3-bis (aminomethyl) cyclohexane, 1,4-bis (aminomethyl) cyclohexane, norbornanediamine, 4,4'- Cyclic aliphatic diamine, such as diamino dicyclohexyl methane, etc. are mentioned, These can be used individually or in combination of 2 or more types.

Specific examples of the aromatic diamine include p-phenylenediamine, m-phenylenediamine, 2,4-toluenediamine, m-xylylenediamine, p-xylylenediamine, 1,5-diaminonaphthalene, 2,6 Aromatic diamine having one aromatic ring, such as -diaminonaphthalene, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl ether, 3 , 4'-diaminodiphenylether, 3,3'-diaminodiphenylether, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diamino Diphenylsulfone, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4 -(3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy) phenyl] propane, 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl (may be described as TFMB), 4,4'-bis (4-ami Nophenoxy) biphenyl, 9,9-bis (4-aminophenyl) fluorene, 9,9-bis (4-amino-3-methylphenyl) fluorene, 9,9-bis (4-amino-3- And aromatic diamines having two or more aromatic rings, such as chlorophenyl) fluorene and 9,9-bis (4-amino-3-fluorophenyl) fluorene. These can be used individually or in combination of 2 or more types.

As aromatic diamine, Preferably, 4,4'- diamino diphenylmethane, 4,4'- diamino diphenyl propane, 4,4'- diamino diphenyl ether, 3,3'- diamino diphenyl ether , 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 1,4-bis (4-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] Sulfone, bis [4- (3-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-aminophenoxy ) Phenyl] propane, 2,2'-dimethylbenzidine, 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl (TFMB), 4,4'-bis (4-aminophenoxy C) biphenyl, more preferably 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylether, 4,4'-diamino Diphenylsulfone, 1,4-bis (4-aminophenoxy) benzene, bis [4- (4-aminophenoxy) phenyl] sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] Propane, 2,2'-dimethylbenzidine, 2,2'- (Trifluoromethyl) scan is 4,4'-diaminodiphenyl (TFMB), 4,4'- bis (4-aminophenoxy) biphenyl. These can be used individually or in combination of 2 or more types.

The said diamine may have a fluorine-type substituent. As a fluorine-type substituent, a C1-C5 perfluoroalkyl group, such as a trifluoromethyl group, and a fluoro group are mentioned.

Among the diamines, from the viewpoint of high transparency and low colorability, it is preferable to use one or more selected from the group consisting of aromatic diamines having a biphenyl structure, and as specific examples, 2,2'-dimethylbenzidine and 2,2'- Preference is given to using at least one member selected from the group consisting of bis (trifluoromethyl) -4,4'-diaminodiphenyl (TFMB) and 4,4'-bis (4-aminophenoxy) biphenyl. . It is more preferable that it is a diamine which has a biphenyl structure and a fluorine-type substituent, and it is more preferable to use 2,2'-bis (trifluoromethyl) -4,4'- diamino diphenyl (TFMB) as a specific example.

The polyimide polymer is a repeating structural unit represented by formula (10), which is formed by polycondensation of a diamine and a tetracarboxylic acid compound (including a tetracarboxylic acid compound derivative such as an acid chloride compound and a tetracarboxylic dianhydride). Condensation type polymer comprising a. As starting materials, in addition to these, tricarboxylic acid compounds (including tricarboxylic acid compound derivatives such as acid chloride compounds and tricarboxylic acid anhydrides) and dicarboxylic acid compounds (including derivatives such as acid chloride compounds) It may be used additionally. Moreover, polyamide is a condensation type polymer containing the repeating structural unit represented by Formula (13) formed by polycondensation of diamine and dicarboxylic acid compounds (including derivatives, such as an acid chloride compound).

The repeating structural unit represented by Formula (10) and Formula (11) is usually derived from diamines and tetracarboxylic acid compounds. The repeating structural unit represented by Formula (12) is usually derived from a diamine and a tricarboxylic acid compound. The repeating structural unit represented by Formula (13) is usually derived from a diamine and a dicarboxylic acid compound. Specific examples of the diamine, tetracarboxylic acid compound, tricarboxylic acid compound, and dicarboxylic acid compound are as described above.

The molar ratio of the diamine and carboxylic acid compounds such as the tetracarboxylic acid compound, to 1.00 mol of the diamine, is preferably adjusted in the range of 0.9 mol or more and 1.1 mol or less, preferably tetracarboxylic acid. In order to express high corrosion resistance, it is more preferable that it is 0.98 mol or more and 1.02 mol or less of tetracarboxylic acid, and 0.99 mol or more and 1.01 mol with respect to 1.00 mol of diamines from the point that it is preferable that the polyimide polymer obtained is high molecular weight. It is more preferable that it is below.

Moreover, it is preferable that the ratio of the amino group to the obtained polymer terminal is low from a viewpoint of suppressing the yellowness of the obtained transparent resin film, and it is preferable that carboxylic acid compounds, such as a tetracarboxylic acid compound, are 1.00 mol or more with respect to 1.00 mol of diamines. .

The amount of fluorine in the polyimide polymer obtained by adjusting the fluorine number in the molecule of the diamine and the carboxylic acid compound (for example, the tetracarboxylic acid compound) is 1% by mass or more based on the mass of the polyimide polymer, It can be 5 mass% or more, 10 mass% or more, and 20 mass% or more. It is preferable that the upper limit of the amount of fluorine is 40 mass% or less, since the raw material cost tends to become expensive, so that the ratio of fluorine is high. The fluorine-based substituent may be present anywhere in the diamine or carboxylic acid compound, or may be present in both of them. In particular, the YI value may be reduced by including a fluorine-based substituent.

The polyimide-based polymer according to the present embodiment may be a copolymer including a plurality of different kinds of the above repeating structural units. The weight average molecular weight of standard polystyrene conversion of a polyimide type polymer is 100,000-800,000 normally. When the weight average molecular weight of a polyimide-type polymer is large, the flexibility at the time of film forming improves, Preferably it is 200,000 or more, More preferably, it is 300,000 or more, More preferably, it is 350,000 or more. Moreover, since the varnish of a suitable density | concentration and a viscosity tends to be obtained, and film forming property tends to improve, Preferably it is 750,000 or less, More preferably, it is 600,000 or less, More preferably, it is 500,000 or less.

By including a fluorine-containing substituent, the polyimide polymer and the polyamide exhibit a tendency to decrease the YI value while improving the elastic modulus when forming a film. If the elastic modulus of the film is high, the occurrence of scratches and wrinkles tends to be suppressed. From the viewpoint of transparency of the film, the polyimide polymer and the polyamide preferably have a fluorine-containing substituent. As a specific example of a fluorine-containing substituent, a fluoro group and a trifluoromethyl group are mentioned.

The content of the fluorine atom in the mixture of the polyimide polymer, the polyimide polymer and the polyamide is based on the sum of the mass of the polyimide polymer or the mass of the polyimide polymer and the mass of the polyamide, respectively. Preferably they are 1 mass% or more and 40 mass% or less, More preferably, they are 5 mass% or more and 40 mass% or less. When content of a fluorine atom is 1 mass% or more, there exists a tendency which can further reduce the YI value at the time of film-forming, and to improve transparency more. When content of a fluorine atom is 40 mass% or less, there exists a tendency for the high molecular weight of polyimide to become easy.

In this invention, content of the polyimide type polymer and / or polyamide in the resin composition to form a transparent resin film becomes like this. Preferably it is 40 mass% or more, More preferably, 50 mass% with respect to solid content of a resin composition. As mentioned above, More preferably, it is 70 mass% or more, and 100 mass% may be sufficient. Flexibility of a transparent resin film is favorable as content of a polyimide polymer and / or a polyamide is more than the said lower limit. In addition, solid content means the total amount of the component remove | excluding the solvent from the resin composition.

In the present invention, the resin composition forming the transparent resin film may further contain an inorganic material such as inorganic particles in addition to the polyimide polymer and / or polyamide. Examples of the inorganic material include inorganic particles such as silica particles, titanium particles, aluminum hydroxide, zirconia particles, barium titanate particles, and silicon compounds such as quaternary alkoxysilanes such as tetraethyl orthosilicate. From the viewpoint of dispersibility of the material, silica particles, aluminum hydroxide and zirconia particles are preferable, and silica particles are more preferable.

The average primary particle diameter of an inorganic material becomes like this. Preferably it is 1-200 nm, More preferably, it is 3-100 nm, More preferably, it is 5-50 nm, More preferably, it is 5-30 nm. There exists a tendency for transparency to improve that the said average primary particle diameter is 100 nm or less. When the average primary particle size is 10 nm or more, the cohesive force of the inorganic material is weakened, so it tends to be easy to handle.

In the present invention, the silica particles may be a silica sol obtained by dispersing the silica particles in an organic solvent or the like, or a silica particle powder produced by a gas phase method may be used.

The average primary particle diameter of the silica particle in a transparent resin film can be calculated | required by observation with a transmission electron microscope (TEM). The particle size distribution of the silica particle before forming a transparent resin film can be calculated | required with a commercially available laser diffraction type particle size distribution meter.

In this invention, content of the inorganic material in a resin composition becomes like this. Preferably it is 0 mass% or more and 90 mass% or less with respect to solid content of a resin composition. More preferably, they are 10 mass% or more and 60 mass% or less, More preferably, they are 20 mass% or more and 50 mass% or less. When content of the inorganic material in a resin composition exists in the said range, there exists a tendency which is easy to make the transparency and mechanical strength of a transparent resin film compatible. In addition, solid content means the total amount of the component remove | excluding the solvent from the resin composition.

The resin composition forming the transparent resin film may further contain other components in addition to the components described above. As another component, antioxidant, a mold release agent, a light stabilizer, a bluing agent, a flame retardant, a lubricating agent, and a leveling agent are mentioned, for example.

In this invention, when a resin composition contains resin components, such as a polyimide polymer, and other components other than an inorganic material, content of another component is 0 mass% or more and 20 mass% or less with respect to the gross mass of a transparent resin film. It is preferable, More preferably, they are 0 mass% or more and 10 mass% or less.

In the present invention, the transparent resin film is, for example, a reaction liquid of a polyimide-based polymer and / or polyamide obtained by reacting by selecting from the tetracarboxylic acid compound, the diamine and the other raw materials, and optionally, inorganic. It can be manufactured with the resin varnish prepared by adding a solvent, mixing, and stirring to the resin composition containing a material and other components. In the above resin composition or resin varnish, a solution such as a purchased polyimide polymer or a solution such as a purchased polyimide polymer may be used instead of a reaction solution such as a polyimide polymer.

As a solvent which can be used in order to prepare a resin varnish, what can dissolve or disperse resin components, such as a polyimide polymer, can be selected suitably. As the solvent, one type may be used alone, or two or more types may be used in combination. In addition, when using 2 or more types of solvent, it is preferable to select the kind of solvent so that the boiling point of the solvent with the highest boiling point in the solvent used may fall in the said range. From the standpoints of solubility, applicability, dryness, etc. of the resin component, an organic solvent having a boiling point of 120 to 300 ° C is preferable, more preferably 120 to 270 ° C, still more preferably 120 to 250 ° C, particularly preferably The organic solvent which has a boiling point of 120-230 degreeC is preferable. Specific examples of such organic solvents include amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone; lactone solvents such as γ-butyrolactone and γ-valerolactone; Ketone solvents such as cyclohexanone, cyclopentanone, and methyl ethyl ketone; Acetic acid ester solvents such as butyl acetate and amyl acetate; Carbonate solvents such as sulfur-containing solvents such as dimethyl sulfone, dimethyl sulfoxide and sulfolane, ethylene carbonate and propylene carbonate, and the like. Among them, N, N-dimethylacetamide (boiling point: 165 ° C), γ-butyrolactone (boiling point: 204 ° C), and N-methylpyrrolidone from the viewpoint of excellent solubility in polyimide polymers and polyamides A solvent selected from the group consisting of (boiling point: 202 ° C), cyclopentanone (boiling point: 131 ° C), butyl acetate (boiling point: 126 ° C) and amyl acetate (boiling point: 149 ° C) is preferable.

The amount of the solvent may be selected so as to be a viscosity capable of handling the resin varnish, and there is no particular limitation. For example, the amount of the solvent is preferably 50 to 95% by mass, more preferably 70 to 95% by mass, based on the total amount of the resin varnish. More preferably, it is 80-95 mass%.

In addition, content of the solvent in the transparent resin film which comprises the laminated body of this invention is residual solvent amount (S) (mass%) calculated as a mass reduction rate in 250 degreeC from 120 degreeC by thermogravimetry-differential heat measurement. It must be the range which satisfy | fills a predetermined relationship in the relationship with the low molecular weight component W (%) in this protective film mentioned later. In this invention, what is necessary is just to adjust suitably the residual solvent amount S in a transparent resin film in relationship with the low molecular weight component W in the protective film bonded together, Preferably it is 20 mass% or less, More preferably, it is more preferable. Preferably it is 17 mass% or less, More preferably, it is 15 mass% or less. When the amount of residual solvent S is below the said upper limit, the transparent resin film obtained can be formed as a self-supporting film. In addition, although the lower limit of residual amount of solvent (S) is not specifically limited, In manufacture of the transparent resin film which consists of a polyimide polymer and a polyamide as a resin component, generally the boiling point exceeding 100 degreeC as mentioned above is mentioned. Since the branched high boiling point solvent is used, it is difficult to completely remove the solvent in the production process, and usually it is 0.001% by mass or more. Moreover, from a viewpoint of flexibility, Preferably it is 0.005 mass% or more, More preferably, it is 0.01 mass% or more, More preferably, it is 0.1 mass% or more, More preferably, it is 0.5 mass% or more.

In the present invention, the residual solvent amount (S) is performed using a thermogravimetric-differential thermal (TG-DTA) measuring device, and the transparent resin film (sample) to be measured is 10 ° C from room temperature to 120 ° C. In the result of the mass change measured by heating up at the temperature increase rate of / min and holding at 120 degreeC for 5 minutes, after removing adsorption water, heating up (heating) at the temperature increase rate of 10 degreeC / min to 400 degreeC, The mass reduction rate S (mass%) over 120 to 250 degreeC is a value computed according to relationship (2).

S (mass%) = 100- (W1 / W0) x 100 (2)

[In formula (2), W0 is the mass of the sample after hold | maintaining at 120 degreeC for 5 minutes, and W1 is the mass of the sample at 250 degreeC in the measurement by the said thermogravimetry-differential heat measuring apparatus. "

The amount of residual solvent S is adjusted by adjusting the amount of solvent contained in the resin varnish for forming the transparent resin film, the solvent species, and the drying conditions (drying temperature and time, wind speed, etc.) of the coating film formed by the resin varnish. Can be controlled.

Although the thickness of a transparent resin film should just be determined suitably according to the use of a transparent resin film, etc., it is 10-500 micrometers normally, Preferably it is 15-200 micrometers, More preferably, it is 20-100 micrometers. When the thickness of a transparent resin film exists in the said range, the flexibility of a transparent resin film is favorable.

The laminated body of this invention contains the protective film bonded to the said transparent resin film. A protective film may be bonded only to one surface of a transparent resin film, and may be bonded to both surfaces. The protective film bonded to a transparent resin film is normally a film for temporarily protecting the surface of a transparent resin film, and is not specifically limited as long as it is a peelable film which can protect the surface of a transparent resin film, polyethylene, poly It is preferable to select from the group which consists of polyolefin resin films, such as a propylene film. When the protective film is bonded to both surfaces of a transparent resin film, the protective film of each surface may be mutually same or different.

In the laminated body of this invention, although the protective film may be comprised from the base film and the adhesive layer formed from acrylic adhesive, an epoxy adhesive, a urethane type adhesive, a silicone type adhesive etc. laminated | stacked on it, for example, a transparent resin film It is preferable that it is a resin film which has self adhesiveness, such as polyolefin resin, from a viewpoint which suppresses contamination to the surface as much as possible.

Moreover, in the whitening of the transparent resin film which is a subject of this invention, the low molecular component contained in a protective film elutes in the solvent used when manufacturing the transparent resin film which uses a polyimide polymer and a polyamide as a resin component. I think it occurs. Among the protective films generally used in the field of the laminate, since the polyolefin resin film tends to contain a relatively large amount of low molecular weight components, the effect of the present invention of suppressing whitening of the transparent resin film is a polyolefin as a protective film. It is especially advantageous in a laminate using a system resin film. Therefore, in one preferred embodiment of the present invention, the protective film used in the laminate of the present invention is easily available and inexpensive in a polyolefin resin film, more preferably a polypropylene resin film or a polyethylene-based resin. It is a resin film, More preferably, it is a polyethylene-type resin film. As the polyethylene resin, for example, high pressure low density polyethylene (LDPE), linear short chain branched polyethylene (LLDPE), medium and low pressure high density polyethylene (HDPE), ultra low density polyethylene (VLDPE), and the like can be cited. As resin of the surface which adjoins a resin film, it is preferable that it is LLDPE from a viewpoint of adhesiveness with a transparent resin film, and workability. In addition, when the protective film is bonded to both surfaces of a transparent resin film, although the protective film of each surface may be mutually same or different, it is preferable that the protective film bonded to at least one surface is a polyolefin resin film.

Here, in this invention, the "low molecular weight component" contained in a protective film is based on the following conditions, Log M of the chart obtained by measuring by gel permeation chromatography in measurement temperature 140 degreeC is 2.82 to 3.32 It means the component detected in the range.

<Measurement Conditions of Gel Permeation Chromatography>

Column: 1 PLgel Individual (5 μm, 50 μs, 7.5 mm ID × 30 cm, made by Agilent Technologies) and 2 TSKgel GMH _HR- H (S) HT (7.5 mm ID × 30 cm, manufactured by Tosoh Corporation) connect

Mobile phase: 0.1 wt / V% of BHT (di-tert-butylhydroxytoluene) is added to orthodichlorobenzene (made by Wako Pure Chemical Industries, Ltd.)

Flow rate: 1 ml / min

Column oven temperature: 140 ℃

Auto sampler temperature: 140 ℃

System oven temperature: 40 ℃

Detection: Differential Refractive Index Detector (RID)

RID cell temperature: 140 ℃

Sample solution injection volume: 300µl

Standard material solution for GPC column calibration: Standard polystyrene manufactured by Tosoh Corporation

In addition, the more detailed measurement conditions of gel permeation chromatography are described in the Example mentioned later.

Specifically, the low-molecular component is considered to be a component derived from the remaining monomers, oligomers and additives contained in the pressure-sensitive adhesive layer, the film raw material, etc., in the protective film, or when the protective film consists of a base film and an adhesive layer laminated thereon. do. As the low molecular weight component contained in the protective film, for example, a nucleating agent, an antioxidant, a hydrochloric acid absorbent, a heat stabilizer, a light stabilizer, an ultraviolet absorber, a lubricant, an anti blocking agent, an antistatic agent, a flame retardant, a pigment, a dye, a dispersant, and a Donghae Iii) As the low molecular weight component included in the pressure-sensitive adhesive layer laminated on the protective film, components derived from flow inhibitors such as flow inhibitors, neutralizing agents, foaming agents, plasticizers, anti-foaming agents, crosslinking agents, peroxides, weld strength improvers, and the like are, for example, The component derived from tackifying resin, a softener, etc. are mentioned.

In this invention, content of the low molecular weight component contained in a protective film follows the measurement conditions of the said gel permeation chromatography, Log M with respect to the whole area of the chart obtained by measuring by the gel permeation chromatography in the measurement temperature of 140 degreeC. The low molecular weight component (W) (%) defined as the ratio of the area from 2.82 to 3.32 satisfies the predetermined relationship in the relationship with the residual solvent amount (S) (mass%) in the transparent resin film described later. It must be a range to make. In the present invention, the low molecular weight component (W) in the protective film may be appropriately adjusted in relation to the amount of residual solvent (S) in the transparent resin film to be bonded, but is preferably 1% or less, and more preferably. Is 0.8% or less, more preferably 0.5% or less, and particularly preferably 0.33% or less. If the low molecular weight component (W) is below the said upper limit, the transfer of the low molecular weight component to the transparent resin film contained in a protective film will hardly arise, and it is suitable as a protective film for protecting the transparent resin film surface for optics. In addition, although the lower limit of the low molecular weight component W is not specifically limited, Since the protective film used in the field of an optical laminated body generally contains the low molecular component derived from the additive and raw material which were illustrated above, it is usually It is 0.00001% or more, Preferably it is 0.001% or more, More preferably, it is 0.01% or more, More preferably, it is 0.02% or more.

Although the thickness of a protective film is not specifically limited, From a viewpoint of protection of a transparent resin film, it is 10 micrometers or more normally, Preferably it is 20 micrometers or more, More preferably, it is 25 micrometers or more. On the other hand, it is preferable that it is 300 micrometers or less from a viewpoint of film handling. When the protective film is bonded to both surfaces of a transparent resin film, the thickness of the protective film of each surface may be same or different.

In the present invention, the residual solvent amount (S) (mass%) of the transparent resin film constituting the laminate and the low molecular weight component (W) (%) of the protective film bonded to the transparent resin film are the relational formula (1) :

S × W≤4.7 (One)

In order to satisfy this, a transparent resin film and a protective film are combined. From the viewpoint of the whitening inhibitory effect, the value of S × W (hereinafter also referred to as “value of formula (1)”) in the laminate of the present invention is preferably 4.5 or less, and more preferably 4.0 or less. It is more preferably 3.5 or less, still more preferably 3.4 or less, particularly preferably 3.3 or less, even more preferably 2.0 or less, particularly preferably 0.5 or less, and even more preferably 0.4 It is as follows.

In addition, S and W are relations (1 '):

0.005≤S × W (One')

In order to satisfy the above, it is preferable that the transparent film and the protective film are combined. The value of S × W (hereinafter also referred to as “value of formula (1 ′)”) in the laminate of the present invention is preferably 0.007 or more.

In addition, when the protective film is bonded on both surfaces of a transparent resin film, the said low molecular weight component amount (W) of each protective film has a relationship with the residual solvent amount (S) of a transparent resin film, respectively, said Formula (1) and a formula It is preferable to satisfy (1 ').

When using the transparent resin film with many residual solvent amounts, the value of Formula (1) selects the protective film with low amount of low molecular weight components, and, on the other hand, when using the protective film with many low molecular weight components, it is transparent resin with little residual solvent amount. It can control by selecting a film.

The laminated body of this invention is excellent in the effect which suppresses the whitening of the transparent resin film surface which bonded the protective film by controlling the residual solvent amount of a transparent resin film and the low molecular weight component amount of a protective film. For this reason, the transparent resin film which comprises the laminated body of this invention is excellent in transparency, The haze becomes like this. Preferably it is 1.0% or less, More preferably, it is 0.7% or less, More preferably, it is 0.5% or less. Moreover, the total light transmittance of the transparent resin film which comprises the laminated body of this invention becomes like this. Preferably it is 85% or more, More preferably, it is 87% or more, More preferably, it is 90% or more. Moreover, the yellowness of the transparent resin film which comprises the laminated body of this invention becomes like this. Preferably it is 3.0 or less, More preferably, it is 2.5 or less, More preferably, it is 2.2 or less. When the haze and total light transmittance of the transparent resin film which comprise a laminated body exist in the said range, it becomes a suitable laminated body for the optical use which requires high transparency. Moreover, since the yellowness of a transparent resin film is low and coloring is suppressed, the laminated body of this invention is suitable for an optical use. In addition, the "whitening of a transparent resin film" in this invention can be identified by irradiating the high brightness light of luminous flux 3000 lumens, as described in the Example mentioned later, and generation | occurrence | production of "whitening" is transparent It does not necessarily directly affect the haze or total light transmittance of a resin film. Since the transparent resin film which peels a protective film from the laminated body of this invention and is used hardly whitens the film surface, and is excellent in transparency, when using the said transparent resin film, for example, a resin film with low transmittance | permeability is used. Compared with the case of use, it is easy to secure a constant brightness, and it becomes possible to suppress the light emission intensity of a display element or the like. For this reason, power consumption can be reduced.

The laminated body of this invention can be manufactured by bonding a transparent resin film and a protective film using a well-known method and apparatus / equipment. Specifically, for example,

Applying a resin varnish obtained by mixing and stirring a resin composition for forming a transparent resin film on a support substrate;

Removing the solvent by drying the applied resin varnish and forming a layer of a transparent resin film on the supporting substrate;

Bonding a protective film to the surface on the side opposite to the supporting substrate of the transparent resin film formed on the supporting substrate; And

It can manufacture by the method containing peeling a support base material from the layer of the transparent resin film formed on the support base material.

For example, when manufacturing a transparent resin film continuously by the method including the process of apply | coating and forming into a film the resin varnish containing a solvent represented by the casting method, and drying, by drying, It is difficult to remove a solvent completely, and it is often used for the next process, with a solvent remaining in a transparent resin film, and whitening easily arises when bonding a protective film. Even in such a case, the relationship of the said Formula (1) is selected by selecting a protective film so that the relationship of Formula (1) may be satisfied according to the amount of residual solvent in a transparent resin film, and also according to the low molecular-component content of the protective film to be used. By controlling the drying conditions of a transparent resin film so that it may satisfy | fill, the whitening which arises on the transparent resin film surface which bonded the protective film can be suppressed easily, and can be effectively suppressed. Moreover, it is preferable to satisfy said formula (1 ').

When the laminated body of this invention is manufactured by the said method, the support base material which apply | coats a resin varnish may be a film-shaped base material, for example, a resin film base material and a steel base material (for example, SUS belt). As a resin film base material, there exists a polyethylene terephthalate (PET) film, for example. The thickness of a support base material is not specifically limited, For example, it is 10-500 micrometers, Preferably it is 50-300 micrometers.

In the drying process of a coating film, it is preferable to remove a solvent by drying so that the solvent in a resin varnish may be a desired range. Drying for removing the solvent may be performed by natural drying, ventilation drying, heat drying or reduced pressure drying, or a combination thereof. From a viewpoint of production efficiency etc., heat drying is preferable. What is necessary is just to determine drying conditions suitably in the range which does not impair the optical characteristic of a transparent resin film according to the kind of solvent used, solvent content in a film, etc. For example, you may heat at 50-300 degreeC, Preferably it is 70-250 degreeC, for example, about 5 to 100 minutes.

Subsequently, the protective film of the low molecular weight component which satisfy | fills the relationship of said Formula (1) is bonded together to the surface on the opposite side to the support base material of a transparent resin film, the layer of a transparent resin film is formed on a support base material, and the said transparent resin film A laminated film obtained by further laminating a protective film on a layer of is obtained. Then, the laminated | multilayer film which bonded the protective film to the transparent resin film can be obtained by peeling a support base material from the layer of a transparent resin film. As needed, you may bond a protective film to the surface of the transparent resin film which peeled the support base material.

Since the laminated body of this invention can suppress the whitening in the surface of the transparent resin film which bonded the protective film, and has high transparency and a favorable appearance, it is optical use, such as a display of various image display apparatuses, especially a flexible display. It can use suitably for a front plate (window film). Examples of the image display apparatus include a wearable device such as a television, a smartphone, 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 a flexible display, the image display apparatus which has flexible characteristics, for example, a television, a smart phone, a mobile telephone, car navigation, a tablet PC, a portable game machine, an electronic paper, an indicator, a bulletin board, a clock, a wearable device, etc. are mentioned.

(Example)

Hereinafter, the present invention will be described in more detail with reference to Examples. "%" And "part" in an example are the mass% and a mass part, unless there is particular notice. In addition, the residual solvent amount of the transparent resin film used by the Example and the comparative example and the low molecular weight component amount of the protective film were respectively measured and calculated according to the following method.

<Measurement Method of Residual Solvent Amount (S)>

Thermogravimetry-Differential Heat (TG-DTA) Measurement

As a measuring device of TG-DTA, TG / DTA6300 made by Hitachi High-Tech Science Co., Ltd. was used. About 20 mg of sample was obtained from the produced transparent polyimide-type film. The temperature of the sample is increased by heating at a temperature increase rate of 10 ° C./min from room temperature to 120 ° C., holding at 120 ° C. for 5 minutes, and then heating (heating) at 400 ° C. at a temperature increase rate of 10 ° C./min. Was measured. 1 shows the TG-DTA measurement result of the transparent polyimide film produced in Example 1 described later.

From the TG-DTA measurement result, the mass reduction rate S (mass%) from 120 degreeC to 250 degreeC was computed according to relationship (2).

S (mass%) = 100- (W1 / W0) x 100 (2)

[In formula (2), W0 is the mass of the sample after holding at 120 degreeC for 5 minutes, and W1 is the mass of the sample in 250 degreeC.).

The calculated mass reduction rate S was referred to as the amount of residual solvent S (mass%) in the transparent resin film.

<Measurement method of low molecular weight component>

The low molecular weight component is determined by gel permeation chromatography (GPC). GPC measurement is performed on condition of the following. The low molecular weight component is determined by gel permeation chromatography (GPC). About the obtained chromatogram, the chart which plotted the electric signal value (intensity (Y)) derived from the refractive index difference of the test object solution and a reference solution with respect to polystyrene conversion molecular weight Log M was obtained. About this chart, the line which Log M connected the points of 2.82 and 7.61 defined as the baseline. In addition, it was set as 0 about the part where the intensity | strength Y value corrected by the baseline became negative.

(1) Sample solution preparation conditions

Solvent: 0.1 wt / V% of BHT (di-tert-butylhydroxytoluene) is added to orthodichlorobenzene (made by Wako Pure Chemical Industries, Ltd.)

Sample solution concentration: 1 mg / ml

Automatic shaker for melting: DF-8020 (manufactured by Tosoh Corporation)

Dissolution condition: A 5 mg sample was sealed in a wire mesh pouch made of SUS of 1000 mesh, a wire mesh pouch containing the sample was placed in a test tube, and 5 ml of solvent was added to the test tube. Subsequently, the test tube which covered with aluminum foil was set to DF-8020, and it stirred at 140 degreeC and 120 minutes at the stirring speed of 60 round trips / minute.

(2) measurement conditions

(GPC device and software)

Measuring apparatus: HLC-8121 GPC / HT manufactured by Tosoh Corporation (manufactured by Tosoh Corporation)

Measurement Software: GPC-8020 modelⅡ Data Collection Version 4.32 (manufactured by Tosoh Corporation)

Analysis software: GPC-8020 modelⅡ data analysis Version 4.32 (manufactured by Tosoh Corporation)

(Measuring conditions)

GPC column: 1 PLgel Individual (5µm, 50mm, 7.5mm ID × 30cm, made by Agilent Technologies), and 2 TSKgel GMH _HR- H (S) HT (7.5mm ID × 30cm, manufactured by Tosoh Corporation) Connect

Mobile phase: Used by adding 0.1w / V% of BHT to orthodichlorobenzene (made by Wako Pure Chemical Co., Ltd.)

Flow rate: 1 ml / min

Column oven temperature: 140 ℃

Auto sampler temperature: 140 ℃

System oven temperature: 40 ℃

Detection: Differential Refractive Index Detector (RID)

RID cell temperature: 140 ℃

Sample solution injection volume: 300µl

Standard material solution for GPC column calibration: Standard polystyrene manufactured by Tosoh Co., Ltd. was weighed in the mass as shown in the following table, and 5 ml of orthodichlorobenzene (the same composition as the mobile phase) was added to dissolve completely at room temperature.

From the GPC measurement result, the low molecular weight component (W) (%) was calculated by the relational formula (3).

W (%) = V0 / V1 (3)

[In Formula (3), V0 is the area of Log M in the chart obtained from the GPC measurement from 2.82 to 3.32, and V1 is the area of the entire chart.

<Measurement method of elastic modulus>

The transparent resin film obtained by the Example and the comparative example was dried at 200 degreeC for 20 minute (s), it cut into 10 mm x 100 mm single stand shape using the dumbbell cutter, and the sample was obtained. Using the Autograph AG-IS manufactured by Shimadzu Corporation, the elastic modulus of this sample was measured on an SS curve under the conditions of a distance of 500 mm between chucks and a tensile speed of 20 mm / min, and from the inclination of the optical film. The elastic modulus was calculated.

<Measurement method of total light transmittance>

The transparent resin film obtained by the Example and the comparative example is cut into the magnitude | size of 30 mm x 30 mm, and is 50 micrometers in thickness of an optical film using a haze computer (manufactured by Suga Tester Co., Ltd., "HGM-2DP"). The total light transmittance of (%) was measured.

<Measuring method of haze value>

The transparent resin film obtained by the Example and the comparative example was cut into the magnitude | size of 30 mm x 30 mm, and haze (%) was measured using the haze computer ("HGM-2DP" made by Suga Test Machine Co., Ltd.).

<Measurement method of yellowness>

The transparent resin film obtained by the Example and the comparative example was cut into the magnitude | size of 30 mm x 30 mm, and tristimulus value (X, Y was used using the ultraviolet visible near-infrared spectrophotometer (V-670 by Nippon Kagaku Co., Ltd.). And Z) were calculated | required and substituted into calculation formula (4), and YI value was computed.

YI = 100 × (1.2769X-1.0592Z) / Y (4)

Preparation Example 1 Preparation of Transparent Polyimide Polymer

A reactor equipped with a silica gel tube, a stirring device, and a thermometer was attached to the separable flask, and an oil bath was prepared. In this flask, 75.52 g of 4,4 '-(hexafluoroisopropylidene) diphthalic anhydride (6FDA) and 2,2'-bis (trifluoromethyl) -4,4'-diaminodiphenyl ( TFMB) 54.44 g was added. 519.84 g of N, N-dimethylacetamide (DMAc) was added while stirring at 400 rpm, and stirring was continued until the contents of the flask became a uniform solution. Subsequently, stirring was further continued for 20 hours, and it reacted to produce polyamic acid, adjusting so that the temperature inside a container might be in the range of 20-30 degreeC using an oil bath. After 30 minutes, the stirring speed was changed to 100 rpm. After stirring for 20 hours, the reaction system temperature was returned to room temperature, and 649.8 g of DMAc was added to adjust the polymer concentration to 10% by weight. Further, 32.27 g of pyridine and 41.65 g of acetic anhydride were added, followed by stirring at room temperature for 10 hours to perform imidization. The polyimide varnish was taken out from the reaction vessel. The obtained polyimide varnish was dripped in methanol, reprecipitation was carried out, the obtained powder was heat-dried, the solvent was removed, and the transparent polyimide polymer was obtained as solid content. The GPC measurement of the obtained polyimide polymer showed a weight average molecular weight of 360,000.

Preparation Example 2 Preparation of Transparent Polyamide-imide Polymer

TFMB 50g (156.13 mmol) and DMAc 642.07g were added to the 1 L separable flask with a stirring blade under nitrogen gas atmosphere, and TFMB was dissolved in DMAc, stirring at room temperature. Next, 20.84 g (46.91 mmol) of 6FDA was added to the flask, and the mixture was stirred at room temperature for 3 hours. Thereafter, 9.23 g (31.27 mmol) of 4,4'-oxybis (benzoyl chloride) (OBBC) was added to the flask, followed by 15.87 g (78.18 mmol) of terephthaloyl chloride (TPC), followed by stirring at room temperature for 1 hour. It was. Subsequently, 9.89 g (106.17 mmol) of 4-methylpyridine and 14.37 g (140.73 mmol) of acetic anhydride were added to the flask, and after stirring at room temperature for 30 minutes, the temperature was raised to 70 ° C. using an oil bath, followed by further stirring for 3 hours. And the reaction liquid was obtained.

The obtained reaction liquid was cooled to room temperature, poured into a large amount of methanol in a large shape, and the precipitate precipitated was taken out and immersed in methanol for 6 hours, and then washed with methanol. Next, the precipitate was dried under reduced pressure at 100 ° C to obtain a transparent polyamideimide polymer. When the GPC measurement of the obtained polyamide-imide type polymer was performed, the weight average molecular weight was 420,000.

Preparation Example 3 Preparation of Silica Sol

When using an amorphous silica sol having a BET diameter (average primary particle size measured by the BET method) 27 nm produced by the sol-gel method as a raw material, and γ-butyrolactone (hereinafter referred to as GBL) by solvent substitution A substituted silica sol was prepared. The obtained sol was filtered through a 10 μm membrane filter to obtain a GBL substituted silica sol. As for the obtained GBL substituted silica sol, all were 30-32 mass% silica particles.

Example 1 Preparation of Laminate

The transparent polyimide-based polymer obtained in Production Example 1 was dissolved in a mixed solvent obtained by mixing γ-butyrolactone (GBL) and DMAc at 1: 9 at a concentration of 16.5% to obtain a resin varnish. The obtained resin varnish was apply | coated and formed into a film on the polyethylene terephthalate (PET) film base material (188 micrometers in thickness, Toyobo Co., Ltd. product (product name: Cosmoshine (registered trademark) A4100) by casting molding). Then, the coating film was dried by heating at 50 degreeC for 30 minutes and 140 degreeC for 10 minutes, and the PET base material was peeled from the coating film. Then, the transparent resin film of thickness about 80 micrometers was obtained by heating at 200 degreeC for 12 minutes. The residual solvent amount of the obtained transparent resin film was 1 mass%. Moreover, the total light transmittance of the obtained transparent resin film was 92.5%, the haze was 0.3%, the yellowness was 2.1 and the elasticity modulus was 4 kPa.

Subsequently, Toray Film Processing Co., Ltd. Tretec (registered trademark) N-711 was prepared as a protective film. The low molecular weight component of the protective film was 0.33%. It bonded together to the produced transparent resin film using the roller and manufactured the laminated body.

<Evaluation of white flower>

Whitening of the obtained transparent resin film was confirmed.

The laminated body manufactured in Example 1 was left still for 24 hours in the environment of the temperature of 23 degreeC, and 50% of humidity. Thereafter, the bonded protective film was peeled off, and the surface of the transparent resin film to which the protective film was bonded was rubbed with a clean waste. Then, the appearance (whitening) of the film was evaluated in accordance with the following evaluation criteria using the high luminance light of luminous flux 3000 lumens. The results are shown in Table 2.

<Evaluation standard of whitening>

(Circle): Whitening was not confirmed.

X: Whitening was confirmed on the surface of a transparent resin film.

(Example 2)

The transparent polyimide-based polymer obtained in Production Example 1 was dissolved in a mixed solvent obtained by mixing γ-butyrolactone (GBL) and DMAc at 1: 9 at a concentration of 16.5% to obtain a resin varnish. The obtained resin varnish was apply | coated and formed into a film on the polyethylene terephthalate (PET) film base material (188 micrometers in thickness, Toyobo Co., Ltd. product (product name: Cosmoshine (registered trademark) A4100) by casting molding). Then, the coating film was dried by heating at 50 degreeC for 30 minutes and 140 degreeC for 10 minutes, the PET base material was peeled from the coating film, and the 80-micrometer-thick transparent resin film was obtained. The residual solvent amount of the obtained transparent resin film was 10 mass%. A laminated body was obtained by the method similar to Example 1 except having used this as a transparent resin film. By the method similar to Example 1, the external appearance (whitening) of the film was evaluated. The results are shown in Table 2.

(Example 3)

As a protective film, the laminated body was obtained by the method similar to Example 1 except having used Tretech 7832C (Toray Film Processing Co., Ltd. product, low molecular weight component amount: 0.48%). By the method similar to Example 1, the external appearance (whitening) of the film was evaluated. The results are shown in Table 2.

(Example 4)

As a protective film, the laminated body was obtained by the method similar to Example 2 except having used Trepan (trademark) BO 25-MK01 (made by Toray Corporation, the amount of low molecular weight components: 0.04%). By the method similar to Example 1, the external appearance (whitening) of the film was evaluated. The results are shown in Table 2.

(Example 5)

The laminated body was obtained by the method similar to Example 2 except having melt | dissolved the transparent polyamide-imide type polymer obtained by the said manufacture example 2 in the density | concentration of 10% in DMAc solvent, and obtained the resin varnish. By the method similar to Example 1, the external appearance (whitening) of the film was evaluated. The results are shown in Table 2.

(Example 6)

The transparent polyamideimide-based polymer / silica particle mixed varnish having the composition shown in Table 2 by dissolving the transparent polyamideimide-based polymer obtained in Production Example 2 in GBL, and by adding the GBL substituted silica sol obtained in Production Example 3 and sufficiently mixing. (Hereinafter, it may be called mixed varnish.). At that time, the mixed varnish was prepared so that the polyamide-imide polymer / silica particle concentration (concentration with respect to the total mass of the resin and silica particles) was 10 mass%. Then, the obtained mixed varnish was apply | coated and formed into a film on the polyethylene terephthalate (PET) film base material (188 micrometers in thickness, Toyobo Co., Ltd. product (product name: Cosmoshine (trademark) A4100) by casting molding). Then, the coating film was dried by heating at 50 degreeC for 30 minutes and 140 degreeC for 10 minutes, the PET base material was peeled from the coating film, and the 50-micrometer-thick transparent resin film was obtained. The residual solvent amount of the obtained transparent resin film was 14 mass%. A laminated body was obtained by the method similar to Example 1 except having used this as a transparent resin film. By the method similar to Example 1, the external appearance (whitening) of the film was evaluated. The results are shown in Table 2.

(Example 7)

The transparent polyamide-imide polymer obtained in Production Example 2 was dissolved in DMAc at a concentration of 12% to obtain a resin varnish. The laminated body was obtained by the method similar to Example 2 except having changed the drying conditions of the coating film at 70 degreeC for 30 minutes, and 140 degreeC for 15 minutes. By the method similar to Example 1, the external appearance (whitening) of the film was evaluated. The results are shown in Table 2.

(Example 8)

After peeling a PET base material from a coating film, the laminated body was obtained by the method similar to Example 1 except having heated at 200 degreeC for 14 hours. The thickness of the obtained transparent resin film was 79 micrometers, and the amount of residual solvent was 0.024 mass%. By the method similar to Example 1, the external appearance (whitening) of the film was evaluated. The results are shown in Table 2.

(Comparative Example 1)

As a protective film, the laminated body was obtained by the method similar to Example 2 except having used Tretech 7832C (Toray Film Processing Co., Ltd. product, low molecular weight component amount: 0.48%). By the method similar to Example 1, the external appearance (whitening) of the film was evaluated. The results are shown in Table 2.

(Comparative Example 2)

As a protective film, the laminated body was obtained by the method similar to Example 6 except having used Tretech 7832C (Toray Film Processing Co., Ltd. product, low molecular weight component amount: 0.48%). By the method similar to Example 1, the external appearance (whitening) of the film was evaluated. The results are shown in Table 2.

Claims (6)

The transparent resin film which consists of at least 1 sort (s) and 1 or more sort (s) of solvent chosen from the group which consists of a polyimide, polyamide, and polyamide imide, and is manufactured using the said 1 or more solvent by the casting method, and the said transparent In the laminated body which consists of a protective film bonded to at least one surface of the resin film,
The boiling point of the solvent with the highest boiling point among the said 1 or more types of solvents is 120-300 degreeC,
Measurement of residual solvent amount (S) (mass%) of the said transparent resin film and the said protective film which are calculated as a mass reduction rate in 120 degreeC from 250 degreeC by thermogravimetry-differential heat (TG-DTA) measurement The amount of low molecular weight component (W) (%) defined as a ratio of the area from 2.82 to 3.32 for the log area of the chart obtained by measurement by gel permeation chromatography at a temperature of 140 ° C is represented by the relation (1):
S × W≤4.7 (1)
To satisfy
W is 0.33 or less,
The laminated body whose thickness of the said transparent resin film is 10-500 micrometers. The method of claim 1,
S and W are relations (1 '):
0.005≤S × W (1 ')
To satisfy the laminate. The method according to claim 1 or 2,
The laminated body whose haze of a transparent resin film is 1.0% or less. The method according to any one of claims 1 to 3,
The laminated body whose total light transmittance of a transparent resin film is 85% or more. The method according to any one of claims 1 to 4,
Lamination | stacking which a transparent resin film contains at least 1 solvent chosen from the group which consists of N, N- dimethylacetamide, (gamma) -butyrolactone, N-methylpyrrolidone, cyclopentanone, butyl acetate, and amyl acetate. sieve. The method according to any one of claims 1 to 5,
The laminated body whose protective film is a polyolefin resin film.

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