JP2013067718A - Optical laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide film that absorbs only near-infrared rays in addition to having excellent heat resistance.SOLUTION: The polyimide film includes a layer A comprising an alicyclic polyimide resin having at least a repeating unit shown by general formula (I) (wherein, R is a quadrivalent alicyclic hydrocarbon group having 4-16 carbons, Φ is a divalent group including at least one group chosen from an aliphatic hydrocarbon group of 2-28 carbons, an alicyclic hydrocarbon group of 3-28 carbons, and an aromatic hydrocarbon group of 6-27 carbons) and optionally includes a hard coating layer B comprising a hard coating agent, wherein the layer A comprising the alicyclic polyimide resin and/or hard coating layer B contains a dye which absorbs the light whose wavelength is in a near-infrared region, and the content of dye within the layer A comprising the alicyclic polyimide resin or hard coating layer B is 0.01-20 wt.%.

Description

  The present invention relates to an optical film used for a near-infrared cut filter comprising a polyimide resin and a dye that absorbs near-infrared rays.

  A polyimide resin is known as a resin having excellent heat resistance and excellent mechanical strength. Generally, as the polyimide resin, a film of wholly aromatic polyimide resin obtained by polycondensation reaction of aromatic tetracarboxylic dianhydride and aromatic diamine is widely used (Patent Document 1).

However, such wholly aromatic polyimide resins have excellent heat resistance and mechanical properties, but have absorption in the short wavelength region of visible light. For this reason, it colored from light yellow to reddish brown, and in order to selectively show only the color derived from the pigment, it was necessary to devise such as increasing the pigment content or reducing the thickness of the polyimide resin layer. For example, a polyimide resin composition for optical filters and an optical filter obtained by mixing a wholly aromatic polyimide resin having a specific structure and a dye having absorption in the visible light region are disclosed (Patent Document 2). However, the optical filter described in the above document is specifically a polyimide resin composition formed on a transparent substrate to a thickness of about 2 μm by a technique such as spin coating, and the polyimide resin composition is a film. It does not have a self-holding ability.

  Patent Document 3 discloses that a resin composition containing a cyclic olefin-based resin and a near-infrared-absorbing dye is used as the near-infrared-absorbing molded article, but the resin composition is sufficient in terms of heat resistance. It can not be said.

  In general, in the alicyclic polyimide resin that uses an aliphatic monomer as the monomer constituting the polyimide, the charge transfer between the tetracarboxylic dianhydride part and the diamine part is suppressed, so that visible light It is known that absorption in the short wavelength region is suppressed (Non-Patent Document 1).

JP-A-55-91895 JP-A-8-100122 JP 2005-97495 A

Latest Polyimides-Fundamentals and Applications-Japan Polyimide Society 3rd chapter 1st chapter

  An object of the present invention is to solve the problems of conventionally used materials and to provide an optical film having a high light transmittance in the visible light region and excellent heat resistance.

  As a result of diligent studies to solve the above problems, the present inventors have absorbed (1) light having a wavelength in the near infrared region into an alicyclic polyimide resin having a repeating unit having an alicyclic tetracarboxylic acid structure. (2) A polyimide film formed by combining a layer made of the alicyclic polyimide resin and a hard coating layer made of a hard coating agent, and made of the alicyclic polyimide resin. In a polyimide film in which a predetermined amount of the dye is dispersed in at least one of a layer and a hard coating layer, it has been found that it has excellent near-infrared absorption characteristics, high light transmittance in the visible light region, and excellent heat resistance. The present invention has been reached.

That is, the present invention relates to a polyimide film having a layer A composed of an alicyclic polyimide resin having at least a repeating unit represented by the general formula (I) and optionally including a hard coating layer B composed of a hard coating agent. The layer A and / or the hard coating layer B made of the alicyclic polyimide resin contains a dye that absorbs light having a wavelength in the near infrared region in the layer A and / or the hard coating layer B made of the cyclic polyimide resin. It is a polyimide film characterized by having a pigment content of 0.01 to 20% by weight.

（式中、Ｒは炭素数４〜１６の４価の脂環族炭化水素基であり、Φは炭素数２〜２８の脂肪族炭化水素基、炭素数３〜２８の脂環式炭化水素基、及び炭素数６〜２７の芳香族炭化水素基から選ばれる少なくとも１つの基を含む２価の基であり、スルフィド基、スルホニル基、スルフィニル基、カルボニル基、メトキシ基、エステル基、エーテル基、フルオロ基等を含んでもよい。）

(In the formula, R is a tetravalent alicyclic hydrocarbon group having 4 to 16 carbon atoms, and Φ is an aliphatic hydrocarbon group having 2 to 28 carbon atoms or an alicyclic hydrocarbon group having 3 to 28 carbon atoms. And a divalent group containing at least one group selected from an aromatic hydrocarbon group having 6 to 27 carbon atoms, a sulfide group, a sulfonyl group, a sulfinyl group, a carbonyl group, a methoxy group, an ester group, an ether group, (A fluoro group etc. may be included.)

  The polyimide film of the present application is an optical film having a high visible light transmittance and a clear color. In addition, since the polyimide film of the present application is excellent in heat resistance, it has a small dimensional change before and after a heating process such as a dielectric multilayer film deposition process or a soldering process. It can be used as a correction filter.

  The alicyclic polyimide resin used in the present invention has a repeating unit represented by the following general formula (I).

（式中、Ｒは炭素数４〜１６の４価の脂環族炭化水素基であり、Φは炭素数２〜２８の脂肪族炭化水素基、炭素数３〜２８の脂環式炭化水素基、及び炭素数６〜２７の芳香族炭化水素基から選ばれる少なくとも１つの基を含む２価の基であり、スルフィド基、スルホニル基、スルフィニル基、カルボニル基、メトキシ基、エステル基、エーテル基、フルオロ基等を含んでもよい。）

(In the formula, R is a tetravalent alicyclic hydrocarbon group having 4 to 16 carbon atoms, and Φ is an aliphatic hydrocarbon group having 2 to 28 carbon atoms or an alicyclic hydrocarbon group having 3 to 28 carbon atoms. And a divalent group containing at least one group selected from an aromatic hydrocarbon group having 6 to 27 carbon atoms, a sulfide group, a sulfonyl group, a sulfinyl group, a carbonyl group, a methoxy group, an ester group, an ether group, (A fluoro group etc. may be included.)

  The alicyclic polyimide resin of the present application comprises a tetravalent alicyclic tetracarboxylic acid having 4 to 16 carbon atoms or a derivative thereof, an aliphatic diamine having 2 to 28 carbon atoms or an aromatic diamine having 6 to 27 carbon atoms, It is synthesized by reacting in an organic solvent in the presence of an imidization catalyst.

  In the present invention, the “aromatic diamine” means a diamine in which an amino group is directly bonded to an aromatic ring, and an aliphatic group, an alicyclic group, or other substituents may be included in a part of the structure. Good. The “aliphatic diamine” represents a diamine in which an amino group is directly bonded to an aliphatic group or an alicyclic group, and an aromatic group and other substituents may be included in a part of the structure.

  In general, when an aliphatic diamine is used as a constituent component, the polyamic acid as an intermediate product and the aliphatic diamine form a strong complex, and thus it is difficult to obtain a high molecular weight polyimide. Therefore, it is necessary to devise such as using a solvent having a relatively high solubility of the complex, for example, cresol. However, when cyclohexanetetracarboxylic acid or a derivative thereof and an aliphatic diamine are used as components, a complex in which the bond between the polyamic acid and the aliphatic diamine is relatively weak is formed, so that the polyimide can be easily increased in molecular weight.

Examples of the alicyclic tetracarboxylic acid or derivatives thereof include alicyclic tetracarboxylic acid, alicyclic tetracarboxylic acid esters, alicyclic tetracarboxylic dianhydride, and the most preferable. Tetracarboxylic dianhydride.

Examples of the tetravalent alicyclic tetracarboxylic dianhydride having 4 to 16 carbon atoms include 1,2,4,5-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetra Carboxylic dianhydride, bicyclo [2.2.1] heptanetetracarboxylic dianhydride, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic dianhydride And bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic dianhydride, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic dianhydride, and the like. Among these, it is particularly preferable to use 1,2,4,5-cyclohexanetetracarboxylic dianhydride. These alicyclic tetracarboxylic dianhydrides may be used alone or in combination of two or more, more preferably 1,2,4,5-cyclohexanetetracarboxylic dianhydride is used alone. Is good.

Examples of the tetravalent alicyclic tetracarboxylic acid having 4 to 16 carbon atoms include 1,2,4,5-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, and bicyclo [2 2.1] heptanetetracarboxylic acid, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid, bicyclo [2.2.2] octane-2,3 , 5,6-tetracarboxylic acid, 3,3 ′, 4,4′-dicyclohexyltetracarboxylic acid, and the like.

Examples of the tetravalent alicyclic tetracarboxylic acid esters having 4 to 16 carbon atoms include 1,2,4,5-cyclohexanetetracarboxylic acid methyl ester and 1,2,4,5-cyclohexanetetracarboxylic acid dimethyl ester. Ester, 1,2,4,5-cyclohexanetetracarboxylic acid trimethyl ester, 1,2,4,5-cyclohexanetetracarboxylic acid tetramethyl ester, bicyclo [2.2.2] oct-7-ene-2,3 , 5,6-tetracarboxylic acid methyl ester, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid dimethyl ester, bicyclo [2.2.2] oct-7 -Ene-2,3,5,6-tetracarboxylic acid trimethyl ester, bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid te Lamethyl ester, bicyclo [2.2.1] heptanetetracarboxylic acid methyl ester, bicyclo [2.2.1] heptanetetracarboxylic acid dimethyl ester, bicyclo [2.2.1] heptanetetracarboxylic acid trimethyl Ester, bicyclo [2.2.1] heptanetetracarboxylic acid tetramethyl ester, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid methyl ester, bicyclo [2.2.2] ] Octane-2,3,5,6-tetracarboxylic acid dimethyl ester, bicyclo [2.2.2] octane-2,3,5,6-tetracarboxylic acid trimethyl ester, bicyclo [2.2.2] octane -2,3,5,6-tetracarboxylic acid tetramethyl ester, 3,3 ', 4,4'-dicyclohexyltetracarboxylic acid methyl ester, 3,3', 4 '- dicyclohexyl tetracarboxylic acid dimethyl ester, 3,3', 4,4'-dicyclohexyl tetracarboxylic acid trimethyl ester, 3,3 ', 4,4'-dicyclohexyl tetracarboxylic acid tetramethyl ester.

The aliphatic diamine having 2 to 28 carbon atoms is not particularly limited, but 4,4-diaminodicyclohexylmethane, isophoronediamine, ethylenediamine, tetramethylenediamine, norbornanediamine, paraxylylenediamine, metaxylylenediamine, 1,3- Bis (aminomethyl) cyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, hexamethylenediamine, 2,5-dimethylhexamethylenediamine, trimethylhexamethylenediamine, polyethylene glycol bis (3-aminopropyl) ether, Examples include polypropylene glycol bis (3-aminopropyl) ether, 4,4-methylenebis (cyclohexylamine), bicyclohexyldiamine, and siloxane diamine.

The aromatic diamine having 6 to 27 carbon atoms is not particularly limited, but 4,4′-diaminodiphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, 1,3-phenylenediamine, 1,4 -Phenylenediamine, 4,4'-diamino-3,3'-dimethylbiphenyl, 4,4'-diamino-2,2'-dimethylbiphenyl, 4,4'-diamino-2,2'-dimethoxybiphenyl, 4 , 4'-diamino-2,2'-bis (trifluoromethyl) biphenyl, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 9,9-bis (4-Aminophenyl) fluorene, 1,1-bis [4- (4-aminophenoxy) phenyl] cyclohex 2,2-bis (3-aminophenyl) propane, 2,2-bis (4-aminophenyl) propane, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2- Bis [4- (4-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, 1,3-bis (3-amino-α, α-dimethylbenzyl) benzene, 1, 3-bis (4-amino-α, α-dimethylbenzyl) benzene, 1,4-bis (3-amino-α, α-dimethylbenzyl) benzene, 1,4-bis (4-amino-α, α- Dimethylbenzyl) benzene, 1,4-bis (3-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, 1,3-bis ( 4-aminofe Xyl) benzene, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, bis [4- (3-aminophenoxy) phenyl] ketone, bis [4- (4-aminophenoxy) phenyl] ketone, bis [4- (3-aminophenoxy) phenyl] sulfide, bis [4- (4-aminophenoxy) phenyl] sulfide, bis [4- (3-aminophenoxy) phenyl] Ether, bis [4- (4-aminophenoxy) phenyl] ether, bis [4- (3-aminophenoxy) phenyl] sulfone, bis [4- (4-aminophenoxy) phenyl] sulfone, 1- (4-amino Phenyl) -1,3,3-trimethyl-1H-indene-5-amine and the like.

Said aliphatic diamine and aromatic diamine can be used individually or in mixture of 2 or more types.

Among the above diamines, in particular, 1,4-bis (4-amino-α, α-dimethylbenzyl) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, 4,4′-diaminodiphenyl ether, 2, 2-bis [4- (4-aminophenoxy) phenyl] propane, 1- (4-aminophenyl) -1,3,3-trimethyl-1H-indene-5-amine, 9,9-bis (4-amino) Phenyl) fluorene, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, and 4,4-diaminodicyclohexylmethane are preferred because high heat resistance is obtained.

The organic solvent used in the production of the alicyclic polyimide resin of the present invention is preferably a solvent containing at least one structure selected from the group consisting of cyclic ethers, cyclic ketones, cyclic esters, amides, and ureas. Specific examples include, but are not limited to, γ-butyrolactone, N, N-dimethylacetamide, N, N-dimethylformamide, N-methyl-2-pyrrolidone, dimethyl sulfoxide, hexamethylphosphoramide, cyclopentanone, cyclohexanone, It is preferable to contain at least one selected from aprotic polar organic solvents such as 1,3-dioxolane, 1,4-dioxane, tetramethylurea and tetrahydrofuran. Among these, one or more selected from γ-butyrolactone, N, N-dimethylacetamide, N, N-dimethylformamide and N-methyl-2-pyrrolidone is more preferable.

A tertiary amine compound is preferable as the imidization catalyst used in the production of the alicyclic polyimide resin, and specifically, trimethylamine, triethylamine (TEA), tripropylamine, tributylamine, triethanolamine, N, N-dimethyl. Examples include ethanolamine, N, N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, N-methylpiperidine, N-ethylpiperidine, imidazole, pyridine, quinoline, and isoquinoline. It can be carried out in the presence of at least one catalyst.

Although the example of the manufacturing method of an alicyclic polyimide resin is shown below, a manufacturing method is not limited to the following.

A solution in which a diamine is dissolved in an organic solvent at a temperature of 30 ° C. or less and an aliphatic tetracarboxylic acid or a derivative thereof are mixed and reacted at a temperature of 4 to 30 ° C. to obtain a polyamic acid solution. An imidation catalyst is added to the polyamic acid solution, and a dehydration imidation reaction is performed while distilling the generated water out of the system to obtain an alicyclic polyimide resin solution.

The molar ratio of diamine to alicyclic tetracarboxylic acid or derivative thereof (diamine / aliphatic tetracarboxylic acid or derivative thereof) is preferably in the range of 0.95 to 1.05, particularly 0.99 to 1.01. The range of is preferable. If the molar ratio of the diamine to the alicyclic tetracarboxylic acid or derivative thereof is less than 0.95 or exceeds 1.05, the molecular weight becomes low and the material may become brittle.

The proper molar ratio of imidization catalyst and diamine (imidation catalyst / diamine) is preferably in the range of 0.01 to 1.0, particularly preferably in the range of 0.05 to 0.5. When the molar ratio of the imidization catalyst and the diamine is less than 0.01, the catalytic action is small and the imidization reaction is difficult to promote. When the molar ratio is 1.0 or more, the imidation catalyst itself is difficult to remove, which will be described later. This may not only cause coloration of the thin molded article made of the alicyclic polyimide resin composition, but may affect the solubility of the alicyclic polyimide resin.

  In the dehydration imidation reaction, a distillate containing water as a main component is removed from the reaction system by a steam cooling tower attached to the upper part of the reaction tank and a distillate storage device engaged therewith. The reaction temperature is usually in the range of 160 to 200 ° C, preferably in the range of 170 to 190 ° C, more preferably in the range of 180 to 190 ° C. If it is lower than 160 ° C., imidation and high molecular weight may not sufficiently proceed due to insufficient temperature, and if it exceeds 200 ° C., a problem such as the resin scorching on the wall of the reaction vessel when the solution viscosity increases remarkably. May occur. In some cases, an azeotropic dehydrating agent such as toluene or xylene may be used. The reaction pressure is usually atmospheric pressure, but the reaction can also be carried out under pressure as necessary. The holding time for the reaction temperature is at least 1 hour, more preferably 3 hours or more. If it is less than 1 hour, imidization and high molecular weight may not proceed sufficiently. Although there is no upper limit in particular about reaction time, it is normally performed in 3 to 10 hours.

The solid content concentration of the alicyclic polyimide resin with respect to the total weight part including the organic solvent in the above step is preferably 20% by weight to 50% by weight, and more preferably 30% by weight to 40% by weight. If it is less than 20% by weight, the intrinsic viscosity of the polyimide resin is difficult to increase, the increase in the molecular weight does not proceed sufficiently, and the thin molded article may become brittle. On the other hand, if it exceeds 50% by weight, the viscosity of the polyimide resin solution increases with an increase in the intrinsic viscosity of the polyimide resin, which may cause the resin to burn without being uniformly stirred. The temperature for dissolving in the organic solvent is desirably at least 20 ° C. or higher, and preferably in the temperature range of 30 ° C. to 100 ° C. When the temperature is 20 ° C. or lower, the solution viscosity is high and handling may be difficult.

  To the alicyclic polyimide resin solution, excess methanol is mixed and stirred to obtain a precipitate of the alicyclic polyimide resin. After filtering the said deposit, it heats under vacuum and white powdery alicyclic polyimide resin is obtained.

In the above production method, the imidization catalyst may be added before the alicyclic tetracarboxylic acid or its derivative is added. In that case, heating can be started immediately and dehydration imidation can be carried out without having to keep the temperature at or near room temperature, which is generally a reaction condition for forming polyamic acid.

  The layer A composed of an alicyclic polyimide resin used in the present invention is capable of emitting light having a wavelength in the near infrared region arbitrarily with respect to a solution composed of an alicyclic polyimide resin or a solution composed of the alicyclic polyimide resin. It is obtained by forming a dispersion liquid composed of an alicyclic polyimide resin mixed and dispersed with a dye to be absorbed and a filler on a substrate as described later, and then removing the solvent.

The solution made of the alicyclic polyimide resin may be a solution obtained by mixing an alicyclic polyimide resin solution after completion of the synthesis reaction with an organic solvent and diluting it. Moreover, as described in the above paragraph 0034, a solution obtained by dissolving a white powdery alicyclic polyimide resin obtained through a reprecipitation and solvent removal step in an organic solvent may be used.

  Although it does not specifically limit as a method of forming layer A consisting of alicyclic polyimide resin on a substrate, After applying a solution consisting of alicyclic polyimide resin or a dispersion consisting of alicyclic polyimide resin on a substrate, It is obtained by evaporating the solvent by heating.

The content of the alicyclic polyimide resin in the solution composed of the alicyclic polyimide resin or in the dispersion containing the alicyclic polyimide resin is preferably 10 to 50% by weight, and 20 to 40% by weight. Is more preferable. If it is less than 10% by weight, it becomes difficult to maintain the thickness of the layer A made of the alicyclic polyimide resin, or it takes a long time to remove the organic solvent. On the other hand, if it exceeds 50% by weight, the fluidity of the solution or dispersion is deteriorated, and it may be difficult to form the layer A composed of the alicyclic polyimide resin.

Examples of the organic solvent include organic solvents used in the production of the alicyclic polyimide resin exemplified in paragraph 0026. Preferred solvents include N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N -Dimethylformamide, dimethyl sulfoxide, hexamethylphosphoramide, tetramethylene sulfone, p-chlorophenol, m-cresol, 2-chloro-4-hydroxytoluene, 1,3-dioxolane, gamma butyrolactone.

  The dispersion composed of the alicyclic polyimide resin may be mixed with a dye that absorbs light having a wavelength in the near infrared region. Examples of the dye include Adeka Arcles GPZ-103 and GPZ-127 manufactured by ADEKA having a maximum absorption wavelength of 670 nm or more, phthalocyanine dye YMG-6 manufactured by Yamada Chemical Co., Ltd., Kayset Blue K-FL manufactured by Nippon Kayaku Co., Ltd. 1 or more types selected from the group which is can be used suitably.

  The pigment content in the dispersion comprising the alicyclic polyimide resin is 0.01 to 20% by weight, more preferably 0.03 to 1% by weight, based on the solid content in the dispersion. When the amount is less than 0.01% by weight, the near-infrared absorption characteristics cannot be sufficiently obtained. When the amount exceeds 20% by weight, the dye is not easily dispersed and aggregates, resulting in poor appearance.

  In addition, there is no restriction | limiting in particular about the timing which mix | blends a pigment | dye, Any timing before the synthetic reaction of an alicyclic polyimide resin, during a synthetic reaction, and after completion | finish of a synthetic reaction may be sufficient. You may carry out after diluting with a dilution solvent after completion | finish of a synthesis | combination. Further, as described in the above paragraph 0034, a white powdery alicyclic polyimide resin obtained through a reprecipitation and solvent removal step and the organic solvent may be mixed. Especially, since a pigment | dye is hard to decompose | disassemble, it is preferable to mix after diluting after completion | finish of a synthesis | combination. The dye may be mixed in a solid state or a solution state dissolved in a solvent.

  The stirring and dispersing of the dye may be carried out in a stirring tank provided with a stirrer having an appropriate stirring ability, or may be carried out using any apparatus for mixing such as a ball mill.

  Moreover, the dispersion liquid which consists of said alicyclic polyimide resin may contain fillers, such as a calcium carbonate, clay, a silica, glass fiber, and a carbon fiber, in the range which maintains transparency.

In the above, the material of the substrate is preferably made of glass or stainless steel, but may be made of an organic polymer such as polyethylene terephthalate or polyethylene naphthalate.

The solution made of the alicyclic polyimide resin or the dispersion made of the alicyclic polyimide resin may be a known additive such as 2,6-di-t-butyl-4-methylphenol or 2- (1-methylcyclohexyl). ) -4,6-dimethylphenol, 2,2-methylenebis- (4-ethyl-6-t-methylphenol), oxidation of 4,4′-thiobis- (6-t-butyl-3-methylphenol), etc. UV absorbers such as inhibitors, 2,2′-dihydroxy-4-methoxybenzophenone, 2- (2′-hydroxy-4′-n-octoxyphenyl) benzotriazole, pt-butylphenyl salicylate, various interfaces An active agent may be included within a range that maintains transparency.

In the above, a known method can be used as a method of applying a solution made of an alicyclic polyimide resin or a dispersion liquid made of an alicyclic polyimide resin. For example, spin coating, a casting method by die extrusion, a method using an applicator, a coater and the like can be mentioned.

The layer A made of the alicyclic polyimide resin may be used in a state where it is formed on the substrate, and when it has a certain thickness, it may be peeled off from the substrate.

In the above, the following method is mentioned as a method of manufacturing the layer A which consists of an alicyclic polyimide resin which has a certain amount of thickness.
i) A solution composed of an alicyclic polyimide resin or a dispersion composed of an alicyclic polyimide resin is applied on a substrate.
ii) Thereafter, the film is heated at a temperature of 120 ° C. or lower for 30 to 60 minutes to partially evaporate the organic solvent to obtain a film-like resin composition having self-supporting properties.
iii) Next, after peeling off the film-shaped resin composition from the substrate, the ends of the film-shaped resin composition are fixed using a metal fixing jig.
iv) Next, in a nitrogen stream or under reduced pressure, the temperature is raised to at least the boiling point of the organic solvent, preferably 5 to 10 ° C. higher than the boiling point, so as not to cause a sudden boiling of the residual organic solvent while limiting the shrinkage of the film. The film is obtained by drying and annealing at the temperature.
The content of the organic solvent contained in the film is preferably less than 1% by weight. If the content of the organic solvent is 1% by weight or more, not only may the glass transition temperature decrease due to the plasticizing action to cause problems such as thermal deformation, but also due to oxidative decomposition of the solvent during high temperature exposure, etc. There is a risk of coloring. The film thickness is preferably 5 μm or more so as to have self-supporting properties.

The thickness of the layer A made of the alicyclic polyimide resin is preferably 1 μm to 300 μm, and more preferably 5 μm to 200 μm. When the thickness is less than 1 μm, the content of the dye necessary for sufficiently exhibiting near-infrared absorption characteristics in the case of containing a dye absorbing near-infrared in the layer A alone made of alicyclic polyimide resin is 20% by weight. This is not preferable because the dye aggregates as described above. When the thickness exceeds 300 μm, it becomes difficult to form a layer having a uniform thickness.

  The polyimide film of the present invention has a layer A made of an alicyclic polyimide resin, and optionally includes a hard coating layer B made of a hard coating agent.

The polyimide film of the present invention may be laminated with a dielectric multilayer film, an ultraviolet absorption layer, an electron beam absorption layer, an antireflection layer, a color tone correction layer, and a heat dissipation layer in addition to the hard coating layer as necessary.

The dielectric multilayer film is made of silica, titania, alumina, lanthanum fluoride, magnesium fluoride, sodium hexafluoride, zirconium oxide, tantalum pentoxide, niobium pentoxide, lanthanum oxide, yttrium oxide, zinc oxide, zinc sulfide, etc. It is preferable to use it. The method for laminating the dielectric multilayer film is not particularly limited, and examples thereof include a CVD method, a vacuum deposition method, and a sputtering method.
By laminating the dielectric multilayer film, infrared rays can be efficiently absorbed from near infrared rays, and it is suitably used for applications requiring heat resistance such as display device applications, optical device applications, mechanical parts, and electronic parts. For example, it can be used for a visibility correction filter for a solid-state imaging device such as a CCD or a CMOS.

  The hard coating layer B is a high hardness film made of a hard coating agent and has a function of improving scratch resistance.

The hard coating agent used in the present invention is not particularly limited. For example, it is composed of an ultraviolet curable resin, an electron beam curable resin, or a thermosetting resin represented by (meth) acrylates, and includes a photopolymerization initiator and an organic solvent. May be included. As (meth) acrylates, (meth) acrylates such as polyurethane (meth) acrylate and epoxy (meth) acrylate, or other polyfunctional (meth) acrylates can be suitably used.

The hard coating agent may include a dye that absorbs light having a wavelength in the near infrared region. Examples of the dye include ADEKA ARKLEZ GPZ-103 and GPZ-127 manufactured by ADEKA having a maximum absorption wavelength of 670 nm or more, phthalocyanine dye YMG-6 manufactured by Yamada Chemical Co., Ltd., Kayset Blue K- manufactured by Nippon Kayaku Co., Ltd. One or more selected from the group of FL can be suitably used. The pigment content in the hard coating agent is preferably 0.01 to 20% by weight, more preferably 0.1 to 10% by weight, based on the solid content. When the amount is less than 0.01% by weight, sufficient absorption characteristics cannot be obtained. When the amount exceeds 20% by weight, it is difficult to disperse and agglomerate to cause poor appearance.

Further, the hard coating agent may contain colloidal metal oxide or silica sol using an organic solvent as a dispersion medium in addition to the above components.

The hard coating layer B may be directly formed on the layer A made of the alicyclic polyimide resin, and the dielectric multilayer film, the ultraviolet absorbing layer, the electron beam absorption on the layer A made of the alicyclic polyimide resin. It may be formed on the laminated film after forming the laminated film comprising at least one layer selected from a layer, an antireflection layer, a color tone correction layer, and a heat dissipation layer. It is preferable to form directly on the layer A which consists of a formula polyimide resin. Hereinafter, the layer A made of the alicyclic polyimide resin or the layer A made of the alicyclic polyimide resin including the laminated film may be simply referred to as “base material”.

A method for forming the hard coating layer B will be described below. After the hard coating agent is applied on the substrate, the solvent in the hard coating agent is removed by heating. Thereafter, it is obtained by curing with ultraviolet rays, electron beams, or heating as necessary. The thickness of the coating layer thus obtained is preferably from 0.1 to 30 μm, more preferably from 1 to 10 μm. If the thickness is less than 0.1 μm, sufficient hardness is difficult to develop. On the other hand, if it exceeds 50 μm, not only curing is difficult, but also it is difficult to form a coat layer having a uniform thickness.

Examples of the method for applying the hard coating agent include known methods such as bar coating, spin coating, blade coating, reverse coating, spray coating, roll coating, gravure coating, lip coating, air knife coating, and dipping.

The hard coating layer B can also be obtained by preparing a self-holding film made of a hard coating agent in advance and bonding it to a substrate via an adhesive layer made of an adhesive or a pressure-sensitive adhesive.

The polyimide film of the present invention preferably has the following light transmittance at a thickness of 100 μm. That is, the light transmittance at a wavelength of 690 nm is preferably 50% or less, and more preferably 30% or less. Moreover, it is preferable that the light transmittance in wavelength 540nm is 80% or more, More preferably, it is 85% or more.

  Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited by these examples.

Evaluation of the obtained polyimide film was performed as follows.
(1) Glass transition temperature Using a differential scanning calorimeter (DSC 6220) manufactured by SII Nanotechnology, Inc., DSC measurement was performed under the condition of a temperature rising rate of 10 ° C./min to obtain a glass transition temperature.
(2) Transmittance Using a UV-3100 manufactured by Shimadzu Corporation, transmittance with respect to light of 350 to 800 nm was measured. A transmittance of less than 30% for a wavelength of 690 nm, ◯ for a transmittance of 30% to less than 50%, × for a transmittance of 50% or more, A for a transmittance of 85% or more for a wavelength of 540 nm, 80 % Or more and less than 85% was rated as ○, and less than 80% was rated as ×.
(3) Turbidity The turbidity was measured using a color / turbidity simultaneous measuring device (COH 400) manufactured by Nippon Denshoku Industries Co., Ltd. (Double-circle): Less than 0.8, (circle): 0.8 or more and less than 2, (x) 2 or more (4) Dimensional change rate Based on JISK7133, the dimensional change rate when heated at 200 degreeC for 30 minutes was measured.
○: Less than 1%, ×: 1% or more

<Reference Example 1>
Synthesis of 1,2,4,5-cyclohexanetetracarboxylic dianhydride Catalyst with 552 g of pyromellitic acid in a 5 liter Hastelloy (HC22) autoclave and rhodium on activated carbon (N.E. NE Chemcat Corporation) 200 g and water 1656 g were charged, and the inside of the reactor was replaced with nitrogen gas while stirring. Next, the inside of the reactor was replaced with hydrogen gas, and the temperature of the reactor was increased to 60 ° C. with a hydrogen pressure of 5.0 MPa. The reaction was carried out for 2 hours while maintaining the hydrogen pressure at 5.0 MPa. The hydrogen gas in the reactor was replaced with nitrogen gas, the reaction solution was extracted from the autoclave, and the reaction solution was filtered while hot to separate the catalyst. The filtrate was concentrated by evaporating water under reduced pressure using a rotary evaporator to precipitate crystals. The precipitated crystals were separated into solid and liquid at room temperature and dried to obtain 481, g (yield: 85.0%) of 1,2,4,5-cyclohexanetetracarboxylic acid.
Subsequently, 450 g of the obtained 1,2,4,5-cyclohexanetetracarboxylic acid and 4000 g of acetic anhydride were charged into a 5-liter glass separable flask (with Dimroth condenser), and the inside of the reactor was stirred. Replaced with nitrogen gas. The temperature was raised to the reflux temperature of the solvent under a nitrogen gas atmosphere, and the solvent was refluxed for 10 minutes. While stirring, the mixture was cooled to room temperature to precipitate crystals. The precipitated crystals were separated into solid and liquid and dried to obtain primary crystals. Further, the separated mother liquor was concentrated under reduced pressure using a rotary evaporator to precipitate crystals. The crystals were separated into solid and liquid and dried to obtain secondary crystals. The primary crystal and the secondary crystal were combined to obtain 375 g of 1,2,4,5-cyclohexanetetracarboxylic dianhydride (anhydrous yield of 96.6%).

<Reference Example 2>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, condenser tube, 1,4-bis (4-amino-α, α-dimethylbenzyl) under nitrogen flow ) Benzene (BisA-P) 12.1 g (0.035 mol) and 4,4′-bis (4-aminophenoxy) biphenyl (BAPB) 5.5 g (0.015 mol) and γ-butyrolactone 34 as the solvent 0.1 g and 8.1 g of N, N-dimethylacetamide were charged and dissolved, and cooled to 5 ° C. using an ice water bath. While maintaining the same temperature, 11.2 g (0.05 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized in Reference Example 1 and 0.25 g (0.0025 mol) of triethylamine as an imidization catalyst were used. ) Was added all at once. Next, the temperature was raised to 180 ° C., and the reaction was carried out for 5 hours while distilling off the distillate. Air cooling was performed until the internal temperature reached 120 ° C., and 71.9 g of N, N-dimethylacetamide was added as a diluent solvent. Cooling with stirring, an organic solvent solution of alicyclic polyimide having a solid concentration of 20% by weight was obtained. The obtained organic solvent solution of polyimide was applied to a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then peeled off from the glass plate to obtain a self-supporting film. This self-supporting film was fixed to a stainless steel fixing jig and dried in a vacuum dryer at 210 ° C. for 2 hours to remove the residual organic solvent, thereby obtaining a colorless, transparent and flexible film having a thickness of 100 μm. When the IR spectrum of this film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1770 and 1704 (cm ⁻¹ ), and it was identified as a polyimide having a repeating unit of the following formula (1). It was.

  The glass transition temperature of the obtained film was 300 ° C. Further, when the total light transmittance of this film was measured according to JIS K7105, it showed a high value of 91%. This polyimide film was heat treated in air at 220 ° C. for 4 hours, and the total light transmittance before and after the heat treatment was measured. However, there was no change at 90%, and no coloration was observed even by visual observation. In addition, the polyimide film was irradiated with a 200 W high-pressure mercury lamp as a light source for 1000 hours in the air (temperature: 60 ° C.) for high energy light treatment, and the total light transmittance was measured similarly. No change was observed, and no coloration was observed by visual observation.

<Reference Example 3>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 10.0 g (0.05 mol) of 4,4′-diaminodiphenyl ether under nitrogen flow After charging and dissolving 34.1 g of γ-butyrolactone and 8.1 g of N, N-dimethylacetamide as a solvent, the mixture was cooled to 5 ° C. using an ice water bath. While maintaining the same temperature, 11.2 g (0.05 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized in Reference Example 1 and 0.25 g (0.0025) of triethylamine as an imidization catalyst were used. Mol) was added all at once. Next, the temperature was raised to 180 ° C., and the reaction was carried out for 5 hours while distilling off the distillate. Air cooling was performed until the internal temperature reached 120 ° C., and 71.9 g of N, N-dimethylacetamide was added as a diluent solvent. Cooling with stirring, an organic solvent solution of alicyclic polyimide having a solid concentration of 20% by weight was obtained. The obtained organic solvent solution of polyimide was applied to a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then peeled off from the glass plate to obtain a self-supporting film. This self-supporting film was fixed to a stainless steel fixing jig and dried in a vacuum dryer at 210 ° C. for 2 hours to remove the residual organic solvent, thereby obtaining a colorless, transparent and flexible film having a thickness of 100 μm. When the IR spectrum of this film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1772, 1700 (cm ⁻¹ ), and it was identified as a polyimide having a repeating unit of the following formula (2). It was.

  The glass transition temperature of the obtained film was 315 ° C. Further, when the total light transmittance of this film was measured according to JIS K7105, it showed a high value of 90%. This polyimide film was heat treated in air at 220 ° C. for 4 hours, and the total light transmittance before and after the heat treatment was measured. However, there was no change at 90%, and no coloration was observed even by visual observation. In addition, the polyimide film was irradiated with a 200 W high-pressure mercury lamp as a light source for 1000 hours in the air (temperature: 60 ° C.) for high energy light treatment, and the total light transmittance was measured similarly. No change was observed, and no coloration was observed by visual observation.

<Reference Example 4>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 2,2-bis [4- (4-aminophenoxy) phenyl] under a nitrogen stream 20.5 g (0.05 mol) of propane, 34.1 g of γ-butyrolactone as a solvent and 8.1 g of N, N-dimethylacetamide were charged and dissolved, and then cooled to 5 ° C. using an ice water bath. While maintaining the same temperature, 11.2 g (0.05 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized in Reference Example 1 and 0.25 g (0.0025 mol) of triethylamine as an imidization catalyst were used. ) Was added all at once. Next, the temperature was raised to 180 ° C., and the reaction was carried out for 5 hours while distilling off the distillate. Air cooling was performed until the internal temperature reached 120 ° C., and 71.9 g of N, N-dimethylacetamide was added as a diluent solvent. Cooling with stirring, an organic solvent solution of alicyclic polyimide having a solid concentration of 20% by weight was obtained. The obtained organic solvent solution of polyimide was applied to a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then peeled off from the glass plate to obtain a self-supporting film. This self-supporting film was fixed to a stainless steel fixing jig and dried in a vacuum dryer at 210 ° C. for 2 hours to remove the residual organic solvent, thereby obtaining a colorless, transparent and flexible film having a thickness of 100 μm. When the IR spectrum of this film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1773 and 1702 (cm ⁻¹ ), and it was identified as a polyimide having a repeating unit of the following formula (3). It was.

  The glass transition temperature of the obtained film was 260 ° C. Further, when the total light transmittance of this film was measured according to JIS K7105, it showed a high value of 90%. This polyimide film was heat treated in air at 220 ° C. for 4 hours, and the total light transmittance before and after the heat treatment was measured. However, there was no change at 90%, and no coloration was observed even by visual observation. In addition, the polyimide film was irradiated with a 200 W high-pressure mercury lamp as a light source for 1000 hours in the air (temperature: 60 ° C.) and subjected to high-energy light treatment, and the total light transmittance was measured similarly. No change was observed, and no coloration was observed by visual observation.

<Reference Example 5>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 4,4′-bis (4-aminophenoxy) biphenyl (BAPB) under a nitrogen stream 18.4 g (0.05 mol), γ-butyrolactone 34.1 g and N, N-dimethylacetamide 8.1 g as a solvent were charged and dissolved, and then cooled to 5 ° C. using an ice water bath. While maintaining the same temperature, 11.2 g (0.05 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized in Reference Example 1 and 0.25 g (0.0025 mol) of triethylamine as an imidization catalyst were used. ) Was added all at once. Next, the temperature was raised to 180 ° C., and the reaction was carried out for 5 hours while distilling off the distillate. Air cooling was performed until the internal temperature reached 120 ° C., and 71.9 g of N, N-dimethylacetamide was added as a diluent solvent. Cooling with stirring, an organic solvent solution of alicyclic polyimide having a solid concentration of 20% by weight was obtained. The obtained organic solvent solution of polyimide was applied to a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then peeled off from the glass plate to obtain a self-supporting film. This self-supporting film was fixed to a stainless steel fixing jig and dried in a vacuum dryer at 210 ° C. for 2 hours to remove the residual organic solvent, thereby obtaining a colorless, transparent and flexible film having a thickness of 100 μm. When the IR spectrum of this film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1773 and 1702 (cm ⁻¹ ), and it was identified as a polyimide having a repeating unit of the following formula (4). It was.

The glass transition temperature of the obtained film was 260 ° C. When this film was measured for total light transmittance according to JIS K7105, this polyimide film showing a high value of 90% was heat-treated at 220 ° C. for 4 hours in air, and the total light transmittance before and after the heat treatment was obtained. Although the rate was measured, there was no change at 90%, and no coloration was observed even by visual observation. In addition, the polyimide film was irradiated with a 200 W high-pressure mercury lamp as a light source for 1000 hours in the air (temperature: 60 ° C.) and subjected to high-energy light treatment, and the total light transmittance was measured similarly. No change was observed, and no coloration was observed by visual observation.

<Reference Example 6>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, condenser tube, 1,4-bis (4-amino-α, α-dimethylbenzyl) under nitrogen flow ) Benzene (BisA-P) 12.1 g (0.035 mol) and 1- (4-aminophenyl) -1,3,3-trimethyl-1H-indene-5-amine (TMDA) 4.0 g (0. 015 mol) and 34.1 g of γ-butyrolactone and 8.1 g of N, N-dimethylacetamide as a solvent were dissolved and then cooled to 5 ° C. using an ice water bath. While maintaining the same temperature, 11.2 g (0.05 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized in Reference Example 1 and 0.25 g (0.0025 mol) of triethylamine as an imidization catalyst were used. ) Was added all at once. Next, the temperature was raised to 180 ° C., and the reaction was carried out for 5 hours while distilling off the distillate. Air cooling was performed until the internal temperature reached 120 ° C., and 71.9 g of N, N-dimethylacetamide was added as a diluent solvent. Cooling with stirring, an organic solvent solution of alicyclic polyimide having a solid concentration of 20% by weight was obtained. The obtained organic solvent solution of polyimide was applied to a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then peeled off from the glass plate to obtain a self-supporting film. This self-supporting film was fixed to a stainless steel fixing jig and dried in a vacuum dryer at 210 ° C. for 2 hours to remove the residual organic solvent, thereby obtaining a colorless, transparent and flexible film having a thickness of 100 μm. When the IR spectrum of this film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1784 and 1703 (cm ⁻¹ ), and it was identified as a polyimide having a repeating unit of the following formula (5). It was.

  The glass transition temperature of the obtained film was 320 ° C. Further, when the total light transmittance of this film was measured according to JIS K7105, it showed a high value of 91%. This polyimide film was heat-treated in air at 220 ° C. for 4 hours, and the total light transmittance before and after the heat treatment was measured. However, there was no change at 91%, and no coloration was observed even by visual observation. In addition, the polyimide film was irradiated with a 200 W high-pressure mercury lamp as a light source for 1000 hours in the air (temperature: 60 ° C.) for high energy light treatment, and the total light transmittance was measured similarly. No change was observed, and no coloration was observed by visual observation.

<Reference Example 7>
In a 500 mL 5-neck flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 9,9-bis (4-aminophenyl) fluorene (BAFL) 13 under a nitrogen stream 9.9 g (0.04 mol) and 4,4′-bis (4-aminophenoxy) biphenyl (BAPB) 3.7 g (0.01 mol), γ-butyrolactone 34.1 g as a solvent, and N, N— After 8.1 g of dimethylacetamide was charged and dissolved, it was cooled to 5 ° C. using an ice water bath. While maintaining the same temperature, 11.2 g (0.05 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized in Reference Example 1 and 0.25 g (0.0025 mol) of triethylamine as an imidization catalyst were used. ) Was added all at once. Next, the temperature was raised to 180 ° C., and the reaction was carried out for 5 hours while distilling off the distillate. Air cooling was performed until the internal temperature reached 120 ° C., and 71.9 g of N, N-dimethylacetamide was added as a diluent solvent. Cooling with stirring, an organic solvent solution of alicyclic polyimide having a solid concentration of 20% by weight was obtained. The obtained organic solvent solution of polyimide was applied to a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then peeled off from the glass plate to obtain a self-supporting film. This self-supporting film was fixed to a stainless steel fixing jig and dried in a vacuum dryer at 210 ° C. for 2 hours to remove the residual organic solvent, thereby obtaining a colorless, transparent and flexible film having a thickness of 100 μm. When the IR spectrum of this film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1775 and 1703 (cm ⁻¹ ), and it was identified as a polyimide having a repeating unit of the following formula (6). It was.

  The resulting film had a glass transition temperature of 410 ° C. Further, when the total light transmittance of this film was measured according to JIS K7105, it showed a high value of 90%. This polyimide film was heat treated in air at 220 ° C. for 4 hours, and the total light transmittance before and after the heat treatment was measured. However, there was no change at 90%, and no coloration was observed even by visual observation. In addition, the polyimide film was irradiated with a 200 W high-pressure mercury lamp as a light source for 1000 hours in the air (temperature: 60 ° C.) and subjected to high-energy light treatment, and the total light transmittance was measured similarly. No change was observed, and no coloration was observed by visual observation.

<Reference Example 8>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 2,2-bis [4- (4-aminophenoxy) phenyl] under a nitrogen stream Hexafluoropropane (25.9 g, 0.05 mol), γ-butyrolactone (34.1 g) and N, N-dimethylacetamide (8.1 g) as a solvent were charged and dissolved, and then cooled to 5 ° C. using an ice water bath. did. While maintaining the same temperature, 11.2 g (0.05 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized in Reference Example 1 and 0.25 g (0.0025 mol) of triethylamine as an imidization catalyst were used. ) Was added all at once. Next, the temperature was raised to 180 ° C., and the reaction was carried out for 5 hours while distilling off the distillate. Air cooling was performed until the internal temperature reached 120 ° C., and 71.9 g of N, N-dimethylacetamide was added as a diluent solvent. Cooling with stirring, an organic solvent solution of alicyclic polyimide having a solid concentration of 20% by weight was obtained. The obtained organic solvent solution of polyimide was applied to a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then peeled off from the glass plate to obtain a self-supporting film. This self-supporting film was fixed to a stainless steel fixing jig and dried in a vacuum dryer at 210 ° C. for 2 hours to remove the residual organic solvent, thereby obtaining a colorless, transparent and flexible film having a thickness of 100 μm. When the IR spectrum of this film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1773 and 1702 (cm ⁻¹ ), and it was identified as a polyimide having a repeating unit of the following formula (7). It was.

  The glass transition temperature of the obtained film was 260 ° C. Further, when the total light transmittance of this film was measured according to JIS K7105, it showed a high value of 91%. This polyimide film was heat-treated in air at 220 ° C. for 4 hours, and the total light transmittance before and after the heat treatment was measured. However, there was no change at 91%, and no coloration was observed even by visual observation. In addition, the polyimide film was irradiated with a 200 W high-pressure mercury lamp as a light source for 1000 hours in the air (temperature: 60 ° C.) for high energy light treatment, and the total light transmittance was measured similarly. No change was observed, and no coloration was observed by visual observation.

<Reference Example 9>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 10.5 g (0.05 mol) of 4,4-diaminodicyclohexylmethane under a nitrogen stream After charging and dissolving 34.1 g of γ-butyrolactone and 8.1 g of N, N-dimethylacetamide as a solvent, the mixture was cooled to 5 ° C. using an ice water bath. While maintaining the same temperature, 11.2 g (0.05 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride synthesized in Reference Example 1 and 0.25 g (0.0025 mol) of triethylamine as an imidization catalyst were used. ) Was added all at once. Next, the temperature was raised to 180 ° C., and the reaction was carried out for 5 hours while distilling off the distillate. Air cooling was performed until the internal temperature reached 120 ° C., and 71.9 g of N, N-dimethylacetamide was added as a diluent solvent. Cooling with stirring, an organic solvent solution of alicyclic polyimide having a solid concentration of 20% by weight was obtained. The obtained organic solvent solution of polyimide was applied to a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then peeled off from the glass plate to obtain a self-supporting film. This self-supporting film was fixed to a stainless steel fixing jig and dried in a vacuum dryer at 210 ° C. for 2 hours to remove the residual organic solvent, thereby obtaining a colorless, transparent and flexible film having a thickness of 100 μm. When the IR spectrum of this film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1691 and 1764 (cm ⁻¹ ), and it was identified as a polyimide having a repeating unit of the following formula (8). It was.

  The resulting film had a glass transition temperature of 281 ° C. Further, when the total light transmittance of this film was measured according to JIS K7105, it showed a high value of 91%. This polyimide film was heat-treated in air at 220 ° C. for 4 hours, and the total light transmittance before and after the heat treatment was measured. However, there was no change at 91%, and no coloration was observed even by visual observation. In addition, the polyimide film was irradiated with a 200 W high-pressure mercury lamp as a light source for 1000 hours in the air (temperature: 60 ° C.) for high energy light treatment, and the total light transmittance was measured similarly. No change was observed, and no coloration was observed by visual observation.

<Reference Example 10>
In a 500 mL five-necked flask equipped with a thermometer, stirrer, nitrogen inlet tube, dropping funnel with side tube, Dean Stark, and condenser tube, 10.0 g (0.05 mol) of 4,4′-diaminodiphenyl ether under nitrogen flow Then, 85 g of N-methyl-2-pyrrolidone as a solvent was charged and dissolved, and then 10.9 g (0.05 mol) of pyromellitic dianhydride was dividedly charged over 1 hour as a solid at room temperature. Stir at room temperature for 2 hours. The obtained organic solvent solution of polyamic acid was applied to a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then peeled off from the glass plate to obtain a self-supporting film. This self-supporting film is fixed to a stainless steel fixing jig and heated in a hot air dryer at 220 ° C. for 2 hours to further evaporate the solvent, and further heated at 300 ° C. for 1 hour to thermally imidize, thereby forming a brown-colored flexible film A film having a thickness of 100 μm was obtained. When the IR spectrum of this film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1772, 1700 (cm ⁻¹ ), and it was identified as a polyimide having a repeating unit of the following formula (9). It was.

  When the total light transmittance of the obtained film was measured with a haze meter (Nippon Denshoku Co., Ltd. Z-Σ80) in accordance with JIS K7105, it was 48%.

<Example 1>
In a 300 mL three-necked flask equipped with a thermometer, a stirrer, a nitrogen introduction tube, and a cooling tube, 110 g of the organic solvent solution of polyimide synthesized in Reference Example 2 (solid content 20 g) and ADEKA ARKLES manufactured by ADEKA Corporation under a nitrogen stream 0.019 g of GPZ-103 was added, heated to 80 ° C. with stirring, and after 1 hour, a resin composition was obtained. Subsequently, the obtained resin composition was applied onto a glass plate, heated on a hot plate at 90 ° C. for 1 hour to evaporate the solvent, and then fixed on a stainless steel fixing jig in a hot air dryer. The solvent was further evaporated by heating at 220 ° C. for 2 hours to obtain a polyimide film having a thickness of 100 μm. The light transmittance and turbidity of the obtained polyimide film were evaluated. The results are shown in Table 1.

<Example 2>
A polyimide film having a thickness of 100 μm was prepared and evaluated in the same manner as in Example 1 except that 0.018 g of YMG-6 manufactured by Yamada Chemical Industries, Ltd. was used instead of 0.019 g of Adeka Arcles GPZ-103. It was. The results are shown in Table 1.

<Example 3>
A polyimide film having a thickness of 100 μm was prepared and evaluated in the same manner as in Example 1 except that 0.016 g of Kayase Blue K-FL manufactured by Nippon Kayaku Co., Ltd. was used instead of 0.019 g of Adeka Arcles GPZ-103. Went. The results are shown in Table 1.

<Example 4>
A polyimide film having a thickness of 100 μm was prepared and evaluated in the same manner as in Example 1 except that the polyimide organic solvent solution synthesized in Reference Example 3 was used instead of the polyimide organic solvent solution synthesized in Reference Example 2. It was. The results are shown in Table 1.

<Example 5>
A polyimide film having a thickness of 100 μm was prepared and evaluated in the same manner as in Example 1 except that the polyimide organic solvent solution synthesized in Reference Example 4 was used instead of the polyimide organic solvent solution synthesized in Reference Example 2. It was. The results are shown in Table 1.

<Example 6>
A polyimide film having a thickness of 100 μm was prepared and evaluated in the same manner as in Example 1 except that the polyimide organic solvent solution synthesized in Reference Example 5 was used instead of the polyimide organic solvent solution synthesized in Reference Example 2. It was. The results are shown in Table 1.

<Example 7>
A polyimide film having a thickness of 100 μm was prepared and evaluated in the same manner as in Example 1 except that the polyimide organic solvent solution synthesized in Reference Example 6 was used instead of the polyimide organic solvent solution synthesized in Reference Example 2. It was. The results are shown in Table 1.

<Example 8>
A polyimide film having a thickness of 100 μm was prepared and evaluated in the same manner as in Example 1 except that the polyimide organic solvent solution synthesized in Reference Example 7 was used instead of the polyimide organic solvent solution synthesized in Reference Example 2. It was. The results are shown in Table 1.

<Example 9>
A polyimide film having a thickness of 100 μm was prepared and evaluated in the same manner as in Example 1 except that the polyimide organic solvent solution synthesized in Reference Example 8 was used instead of the polyimide organic solvent solution synthesized in Reference Example 2. It was. The results are shown in Table 1.

<Example 10>
A polyimide film having a thickness of 100 μm was prepared and evaluated in the same manner as in Example 1 except that the polyimide organic solvent solution synthesized in Reference Example 9 was used instead of the polyimide organic solvent solution synthesized in Reference Example 2. It was. The results are shown in Table 1.

<Example 11>
Reference Example 2 A coating agent obtained by adding 10 g of ethyl acetate and 0.1 g of ADEKA ARKLES GPZ-103 manufactured by ADEKA Corporation to 10 g of Nippon Synthetic Chemical Industry Co., Ltd. hard coating agent UV-7600 (ultraviolet curable resin purple light) The film obtained in 1 above was applied using a bar coater, dried at 60 ° C. for 3 minutes, and then cured by irradiation with light of a high pressure mercury lamp 80 W / cm, 10 cmH, and an integrated light quantity of 450 mJ / cm ² (coating amount 9 μm). ), A polyimide film was prepared and evaluated. The results are shown in Table 1.

<Example 12>
A polyimide film having a coating layer thickness of 7 μm was prepared and evaluated in the same manner as in Example 11 except that 0.1 g of GPZ-127 was used instead of 0.1 g of Adeka Arcles GPZ-103 manufactured by ADEKA Corporation. Went. The results are shown in Table 1.

<Comparative Example 1>
Polyimide having a thickness of 100 μm in the same manner as in Example 1 except that 0.019 g of a cyanine dye (maximum absorption wavelength: 505 nm, 670 nm, 700 nm) manufactured by Sumitomo Seika Chemical Co., Ltd. was used instead of Adeka Arcles GPZ-103 manufactured by ADEKA Corporation. A film was prepared and evaluated. The results are shown in Table 1.

<Comparative example 2>
100 μm in thickness in the same manner as in Example 1 except that 0.019 g of azo dye (maximum absorption wavelength: 550 nm, 570 nm) manufactured by Mitsubishi Chemical Media Co., Ltd. was used instead of ADEKA ARKLES GPZ-103 manufactured by ADEKA Corporation. A polyimide film was prepared and evaluated. The results are shown in Table 1.

<Comparative Example 3>
A polyimide film having a coating amount of 9 μm was prepared and evaluated in the same manner as in Example 11 except that 0.0005 g of Adeka Arcles GPZ-103 manufactured by ADEKA Corporation was used. The results are shown in Table 1.

<Comparative example 4>
A polyimide film having a coating layer thickness of 7 μm was prepared and evaluated in the same manner as in Example 11 except that the film obtained in Reference Example 10 was used instead of the film obtained in Reference Example 2. The results are shown in Table 1.

<Comparative Example 5>
A film having a coating layer thickness of 7 μm was produced in the same manner as in Example 11 except that a cyclic olefin-based resin film (ARTON G7810 thickness 100 μm manufactured by JSR Corporation) was used instead of the polyimide film obtained in Reference Example 2. And evaluated. The results are shown in Table 1.

Claims (4)

In the polyimide film which has the layer A which consists of an alicyclic polyimide resin which has a repeating unit shown by general formula (I) at least, and optionally contains the hard coating layer B which consists of a hard coating agent, the said layer A and / or layer A polyimide film containing a dye that absorbs light having a wavelength in the near infrared region in B and having a dye content in the layer A and / or layer B of 0.01 to 20% by weight.

(In the formula, R is a tetravalent alicyclic hydrocarbon group having 4 to 16 carbon atoms, and Φ is an aliphatic hydrocarbon group having 2 to 28 carbon atoms or an alicyclic hydrocarbon group having 3 to 28 carbon atoms. And a divalent group containing at least one group selected from an aromatic hydrocarbon group having 6 to 27 carbon atoms, a sulfide group, a sulfonyl group, a sulfinyl group, a carbonyl group, a methoxy group, an ester group, an ether group, (A fluoro group etc. may be included.)   The polyimide film according to claim 1, wherein R in the general formula (I) is a tetravalent group derived from cyclohexane.   The polyimide film according to claim 1 or 2, wherein the dye is at least one selected from the group consisting of phthalocyanine dyes, cyanine dyes, azo dyes, and anthraquinone dyes. The maximum absorption wavelength of the said pigment | dye is 670 nm or more, The polyimide film in any one of Claims 1-3.