CN117581124A

CN117581124A - Resin film for polarizing plate, method for producing same, polarizing plate, and display device

Info

Publication number: CN117581124A
Application number: CN202280045751.8A
Authority: CN
Inventors: 西村浩; 藤枝奈奈惠; 大久保康; 田坂公志; 南条崇
Original assignee: Konica Minolta Inc
Current assignee: Konica Minolta Inc
Priority date: 2021-06-29
Filing date: 2022-03-14
Publication date: 2024-02-20
Also published as: TW202309625A; WO2023276310A1; JPWO2023276310A1

Abstract

The invention provides a resin film for a polarizing plate, which suppresses the reduction of adhesion and the deterioration of contrast caused by heat generation of a semiconductor substrate when used for the polarizing plate in a display device, and a polarizing plate and a display device provided with the resin film for a polarizing plate. The resin film for a polarizing plate of the present invention is a resin film for a polarizing plate comprising at least a polarizer layer containing iodine, wherein the resin film for a polarizing plate comprises at least a thermoplastic resin and an iodine migration inhibitor, and has a film thickness of 1 [ mu ] m or more and less than 15 [ mu ] m.

Description

Resin film for polarizing plate, method for producing same, polarizing plate, and display device

Technical Field

The invention relates to a resin film for a polarizing plate, a method for producing the same, a polarizing plate and a display device. More specifically, the present invention relates to a resin film for a polarizing plate, which suppresses a decrease in adhesion and a deterioration in contrast due to heat generation of a semiconductor substrate when used in a polarizing plate for a display device, a method for producing the same, and a polarizing plate and a display device each including the resin film for a polarizing plate.

Background

In recent years, introduction and popularization of the fifth generation mobile communication system (5G) are expected, and development of communication devices corresponding to 5G is advancing. In the case of 5G, the communication speed is significantly higher than that of the 4G of the previous generation, and thus high-speed and large-capacity information processing is required for the communication device corresponding to 5G, and there is a concern that durability is reduced due to heat generation of the device.

In a display device using a polarizer layer obtained by dyeing a polyvinyl alcohol (PVA) film with iodine, it is known that the semiconductor substrate heats up with an increase in the number of times of color switching and the number of pixels due to high definition, and a decrease in contrast due to deterioration of color tone of the display occurs.

As a main cause of the contrast reduction, it is considered that the oriented iodine moves to the PVA iodine-dyed polarizer layer (hereinafter also simply referred to as "polarizer layer") to deteriorate the polarization performance of the polarizer layer. In addition, the protective layer is typically bonded to both sides of the polarizer layer via an adhesive layer. Therefore, it is considered that the moving iodine enters the protective layer, and the adhesion between the protective layer and the polarizer layer is reduced, thereby further promoting the reduction of contrast.

Patent document 1 discloses a technique of a cellulose acylate film containing an iodine intake reducing agent and an acidic component as a polarizer protective film which is capable of suppressing deterioration of polarization performance even when the film transparency is high and at high temperature and high humidity. However, it is known that in a high temperature environment based on a 5G-compliant communication device, multi-iodine (I ₃ ^- Or I ₅ ^- ) Since the movement of the film becomes more active and the film is easily moved, a reactant of polyiodine and an acidic component in the film is deposited at the interface between the protective film and the adhesive layer, and the contrast is lowered.

Patent document 2 discloses a technique of an optical compensation sheet that suppresses a change in optical characteristics due to environmental conditions and makes a generated temperature distribution uniform, as an optical compensation sheet that does not generate light leakage due to thermal strain. Further, when the cellulose acetate film contained in the optical compensation sheet further contains high thermal conductive particles, the thermal conductivity may be 1W/(m·k) or more, and the higher the thermal conductivity, the better the effect.

However, in this technique, in a higher temperature environment based on a communication device corresponding to 5G, the decrease in contrast cannot be suppressed, and there is room for improvement.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication No. 2014-80571

Patent document 2: japanese patent No. 4285919

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above-described problems and situations, and an object of the present invention is to provide a resin film for a polarizing plate, which suppresses a decrease in adhesion and a deterioration in contrast due to heat generation of a semiconductor substrate when used in a polarizing plate in a display device, a method for producing the same, and a polarizing plate and a display device each including the resin film for a polarizing plate.

Technical means for solving the problems

The present inventors have studied the cause of the above problems in a resin film for a polarizing plate including at least a polarizer layer containing iodine, and as a result, have found that by including at least an iodine migration inhibitor, the film thickness is controlled within a specific range, and the migration of multi-iodine is suppressed, thereby suppressing the decrease in adhesion and the deterioration of contrast due to heat generation of a semiconductor substrate, and have completed the present invention.

That is, the problem of the present invention is solved by the following means.

1. A resin film for a polarizing plate, which is used for a polarizing plate having at least a polarizer layer containing iodine, wherein the resin film for a polarizing plate comprises at least a thermoplastic resin and an iodine migration inhibitor, and has a film thickness of 1 [ mu ] m or more and less than 15 [ mu ] m.

2. The resin film for a polarizing plate according to the first aspect, wherein the iodine transfer inhibitor is metal oxide particles, and the resin film for a polarizing plate has a thermal conductivity in the range of 0.2 to 0.6W/m·k.

3. The resin film for a polarizing plate according to the second aspect, wherein the ratio of the average primary particle diameter to the average secondary particle diameter of the metal oxide particles satisfies the following formula (1),

Formula (1): 20< average secondary particle size/average primary particle size <2000.

4. The resin film for a polarizing plate according to the first aspect, wherein the iodine migration inhibitor is a non-organic acid, and a δP (polar force) of hansen solubility parameter (HSP value) of the non-organic acid is 5 to 9MPa ^0.5 Within a range of (2).

5. The resin film for a polarizing plate according to the fourth aspect, wherein a ratio of δD (dispersion force) to δP (polar force) of the HSP value of the non-organic acid satisfies the following formula (2),

formula (2): 2< δd (dispersion force)/δp (polar force) <4.

6. The resin film for a polarizing plate according to the fourth or fifth aspect, wherein the iodine transfer inhibitor further comprises sulfate ions, and the content of the sulfate ions is in the range of 1 to 100 mass ppm with respect to the total mass of the solid components of the resin film for a polarizing plate.

7. The resin film for a polarizing plate according to any one of the first to sixth items, wherein the thermoplastic resin is a cycloolefin resin.

8. A method for producing a resin film for a polarizing plate according to any one of the first to seventh aspects, wherein the method comprises: and a step of coating a solution containing a thermoplastic resin and an iodine migration inhibitor on the release layer using the resin film having the release layer as a support.

9. A polarizing plate comprising an adhesive layer and a polarizer layer on a resin film, wherein the polarizing plate comprises the resin film for a polarizing plate according to any one of the first to seventh aspects as the resin film.

10. The polarizing plate according to claim ninth, wherein the thickness of the polarizer layer is in a range of 4 to 15 μm.

11. A display device including a polarizing plate, wherein the display device includes the polarizing plate according to the ninth or tenth aspect as the polarizing plate.

Effects of the invention

The means of the present invention can provide a resin film for a polarizing plate, which suppresses a decrease in adhesion and a deterioration in contrast due to heat generation of a semiconductor substrate when used in a polarizing plate in a display device, and a polarizing plate and a display device each including the resin film for a polarizing plate.

The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.

In detail, a polarizing function is obtained by dyeing a polyvinyl alcohol (PVA) film with iodine (hereinafter also referred to as "PVA iodine-dyed polarizing layer" or simply as "polarizing layer"), and then stretching the film after dyeing the PVA film with iodine, so that iodine is oriented. In addition, in general, the polarizer layer is laminated with a protective layer (also referred to as "polarizer resin film" in the present invention) on both sides via an adhesive layer.

When the polarizer layer is further thinned, that is, when the PVA film is further thinned, the PVA film is likely to break during stretching, and therefore, sufficient tension cannot be applied to stretch the PVA film, and the orientation is likely to be lowered. In order to make the polarization function equal to that of the conventional one, that is, to contain a polyiodine (I ₃ ^- 、I ₅ ^- ) It is necessary to increase the content of multi-iodine per unit volume.

However, the membrane has a limited amount of polyiodine capable of adsorption orientation, and if the polyiodine is to be adsorbed and oriented in excess of the limit amount, a part of polyiodine cannot be completely adsorbed, and the membrane is in a state of easy detachment (easy movement). Therefore, the orientation is lowered, and the polarization function of the polarizer layer is lowered. In addition, the multi-iodine which is easily moved may further move from the PVA film into the protective layer, degrading the performance of the protective layer.

In particular, in the communication device corresponding to 5G, the semiconductor substrate generates a larger amount of heat than in the conventional device, and is in a higher temperature environment, so that the iodine tends to be moved more actively by the heat energy. Therefore, it is preferable to be able to keep multi-iodine in the PVA film even under a higher temperature environment.

As means for suppressing the movement of iodine, there are a means for reducing the thermal energy absorbed by multi-iodine by heat dissipation in the polarizer layer and a means for preventing the movement of multi-iodine actively moving into the protective layer by charge repulsion with the multi-iodine.

In the present invention, by including an iodine movement inhibitor that inhibits movement of iodine by the means described above in the protective layer, multi-iodine can be held in the PVA film.

In the conventional technique for suppressing movement of iodine, the reaction product is generated by a chemical reaction with the multi-iodine, so that the influence of the multi-iodine on the protective layer is reduced. The reactant is likely to precipitate at the interface between the protective layer and the adhesive layer or at the interface between the adhesive layer and the polarizer layer, resulting in a decrease in adhesion.

However, the iodine migration inhibitor of the present invention can hold multi-iodine in the PVA film, and therefore can suppress a decrease in the polarizing function of the polarizing film, and can suppress a decrease in the adhesion between the polarizer layer and the protective layer because a reactant with multi-iodine is not generated. Therefore, when the resin film for a polarizing plate of the present invention is used as a protective layer for a polarizing plate in a display device, it is possible to suppress a decrease in adhesion and a deterioration in contrast caused by heat generation of a semiconductor substrate.

Drawings

FIG. 1 is a schematic view of a production apparatus B200 for carrying out the method for producing a resin film for a polarizing plate of the present invention

FIG. 2 is a cross-sectional view of the basic layer structure of the polarizing plate of the present invention

Detailed Description

The resin film for a polarizing plate of the present invention is a resin film for a polarizing plate comprising at least a polarizer layer containing iodine, wherein the resin film for a polarizing plate comprises at least a thermoplastic resin and an iodine migration inhibitor, and has a film thickness of 1 [ mu ] m or more and less than 15 [ mu ] m.

This feature is common to or corresponding to the following embodiments.

In an embodiment of the present invention, from the viewpoint of releasing heat in the polarizer layer, the iodine transfer inhibitor is preferably metal oxide particles, and the thermal conductivity of the resin film for a polarizing plate is preferably in the range of 0.2 to 0.6W/m·k.

Further, from the viewpoint of promoting heat dissipation of the metal oxide particles, the ratio of the average primary particle diameter to the average secondary particle diameter of the metal oxide particles preferably satisfies the following formula (1).

Formula (1): 20< average secondary particle diameter/average primary particle diameter <2000

From the viewpoint of exclusion with multi-iodine having electric charges, it is preferable that the iodine transfer inhibitor is a non-organic acid, and δP (polar force) of hansen solubility parameter (HSP value) of the non-organic acid is 5 to 9MPa ^0.5 Within a range of (2).

Further, from the viewpoint of promoting charge repulsion caused by a non-organic acid, the ratio of δd (dispersion force) to δp (polar force) of the HSP value of the non-organic acid preferably satisfies the following formula (2).

Formula (2): 2< delta D (dispersion force)/delta P (polar force) <4

In addition, from the viewpoint of stable polarity of the non-organic acid, it is preferable that the iodine transfer inhibitor further contains sulfate ions, and the content of the sulfate ions is in the range of 1 to 100 mass ppm with respect to the total mass of the solid content of the resin film for a polarizing plate.

The thermoplastic resin is preferably a cycloolefin resin from the viewpoint of improving the water resistance of the polarizing plate.

The method for producing a resin film for a polarizing plate of the present invention comprises: and a step of coating a solution containing a thermoplastic resin and an iodine migration inhibitor on the release layer using the resin film having the release layer as a support.

The resin film for a polarizing plate of the present invention is suitably used for a polarizing plate of the present invention and a display device of the present invention.

In addition, from the viewpoint of obtaining a thinner polarizing plate and display device, the thickness of the polarizing layer is preferably in the range of 4 to 15 μm.

The present invention and its constituent elements, and modes for carrying out the present invention will be described in detail below. In the present application, "to" is used in a meaning including numerical values described before and after the "to" as a lower limit value and an upper limit value. However, when the numerical value is "exceeded" or "undershot", the numerical value is not included as the lower limit value and the upper limit value. For example, "1 to less than 15 μm" refers to "1 μm or more and less than 15 μm" in detail. "

1 resin film for polarizing plate of the present invention

The resin film for a polarizing plate of the present invention can be bonded to a polarizer layer via an adhesive layer to protect the polarizer layer. The polarizer resin film may be used to protect both sides of the polarizer layer, and other conventionally known protective layers may be used.

When the thickness of the resin film for a polarizing plate of the present invention is less than 1. Mu.m, sufficient strength as a protective layer is not obtained. If the thickness is 15 μm or more, the polarizing plate cannot be thinned, and the capacity of a battery mounted in the communication device becomes insufficient.

[1.1 thermoplastic resin ]

In the present invention, the thermoplastic resin means a thermoplastic resin other than the cellulose acylate resin. The resin used is not particularly limited as long as it is a resin other than a cellulose acylate resin, and examples thereof include cycloolefin resins (COP), polycarbonate resins, (meth) acrylic resins, styrene- (meth) acrylate copolymers, fumaric acid diester resins, and polyarylate resins.

From the viewpoint of improving the water resistance of the polarizing plate, the water content of the thermoplastic resin of the present invention is preferably 3.0% or less. The water content can be adjusted to be within the above range by setting the storage environment to 23 ℃ and 55% RH. The water content can be measured by the following method.

About 1g of a thermoplastic resin was prepared, and the mass (WB) of the thermoplastic resin at absolute dryness was measured. After immersing this sample in distilled water at 25℃for 1 hour, the mass (WA) of the sample having an equilibrium state of water content WAs measured, and the water content WAs calculated from the following formula.

Balance water content (% by mass) = { (WA-WB)/WA } ×100

< cycloolefin resin >

In the present invention, the cycloolefin resin is preferably a polymer of cycloolefin monomer or a copolymer of cycloolefin monomer and other copolymerizable monomer.

The cycloolefin monomer is preferably a cycloolefin monomer having a norbornene skeleton, and more preferably a cycloolefin monomer having a structure represented by the following general formula (A-1) or (A-2).

[ chemical formula 1]

General formula (A-1)

In the general formula (A-1), R ¹ ～R ⁴ Each independently represents a hydrogen atom, a hydrocarbon group having 1 to 30 carbon atoms, or a polar group. p represents an integer of 0 to 2. Wherein R is ¹ ～R ⁴ Not all of them simultaneously represent hydrogen atoms, R ¹ And R is ² Not simultaneously representing hydrogen atoms, R ³ And R is ⁴ Not simultaneously representing hydrogen atoms.

As R in the general formula (A-1) ¹ ～R ⁴ The hydrocarbon group having 1 to 30 carbon atoms is preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 5 carbon atoms. The hydrocarbon group having 1 to 30 carbon atoms may further have a linking group containing a halogen atom, an oxygen atom, a nitrogen atom, a sulfur atom or a silicon atom, for example. Examples of such linking groups include 2-valent polar groups such as carbonyl groups, imino groups, ether linkages, silyl ether linkages, thioether linkages, and the like. Examples of the hydrocarbon group having 1 to 30 carbon atoms include methyl, ethyl, propyl, butyl and the like.

R in the general formula (A-1) ¹ ～R ⁴ Examples of the polar group shown include carboxyl, hydroxyl, alkoxy, alkoxycarbonyl, aryloxycarbonyl, amino, amido, and cyano. Among them, carboxyl group, hydroxyl group, alkoxycarbonyl group and aryloxycarbonyl group are preferable, and alkoxycarbonyl group and aryloxycarbonyl group are preferable from the viewpoint of securing solubility at the time of solution film formation.

From the viewpoint of improving the heat resistance of the resin film for a polarizing plate, p in the general formula (a-1) is preferably 1 or 2. This is because, when p is 1 or 2, the volume of the obtained polymer becomes large, and the glass transition temperature tends to be high. In addition, there is an advantage that it is possible to control the curl balance as a laminate easily by making a plurality of responses to humidity.

[ chemical formula 2]

General formula (A-2)

In the general formula (A-2), R ⁵ An alkylsilyl group having a hydrogen atom, a hydrocarbon group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms. R is R ⁶ Represents a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an amino group, an amide group, a cyano group or a halogen atom (fluorine atom, chlorine atom, bromine atom or iodine atom). p represents an integer of 0 to 2.

R in the general formula (A-2) ⁵ Preferably a hydrocarbon group having 1 to 5 carbon atoms, more preferably a hydrocarbon group having 1 to 3 carbon atoms.

R in the general formula (A-2) ⁶ Preferably represents a carboxyl group, a hydroxyl group, an alkoxycarbonyl group and an aryloxycarbonyl group, and more preferably an alkoxycarbonyl group and an aryloxycarbonyl group, from the viewpoint of securing solubility in a solution for film formation.

From the viewpoint of improving the heat resistance of the resin film for a polarizing plate, p in the general formula (a-2) preferably represents 1 or 2. This is because, when p represents 1 or 2, the volume of the obtained polymer becomes large, and the glass transition temperature tends to be high.

From the viewpoint of improving the solubility in an organic solvent, cycloolefin monomers having a structure represented by the general formula (A-2) are preferable. In general, the organic compound has reduced crystallinity due to the breakdown of symmetry, and thus has improved solubility in an organic solvent. R in the general formula (A-2) ⁵ R is R ⁶ Since only one side of the ring-forming carbon atom is substituted with respect to the symmetry axis of the molecule, the symmetry of the molecule is low, that is, the solubility of the cycloolefin monomer having the structure represented by the general formula (A-2) is high, and thus the resin film for a polarizing plate is suitable for the case of producing a resin film for a polarizing plate by a solution casting method.

The content of the cycloolefin monomer having the structure represented by the general formula (A-2) in the polymer of the cycloolefin monomer is preferably 70 mol% or more, more preferably 80 mol% or more, and still more preferably 100 mol% based on the total of all cycloolefin monomers constituting the cycloolefin resin. When the cycloolefin monomer having a structure represented by the general formula (A-2) is contained at a certain value or more, the orientation of the resin is improved, and thus the retardation (retardation) value is liable to rise.

Specific examples of cycloolefin monomers having a structure represented by the general formula (A-1) are shown as exemplified compounds 1 to 14, and specific examples of cycloolefin monomers having a structure represented by the general formula (A-2) are shown as exemplified compounds 15 to 34.

[ chemical formula 3]

Examples of the copolymerizable monomer copolymerizable with the cycloolefin monomer include a copolymerizable monomer capable of ring-opening copolymerization with the cycloolefin monomer, a copolymerizable monomer capable of addition copolymerization with the cycloolefin monomer, and the like.

Examples of the copolymerizable monomer capable of ring-opening copolymerization include cycloolefins such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene.

Examples of the copolymerizable monomer capable of addition copolymerization include unsaturated double bond-containing compounds, vinyl-based cyclic hydrocarbon monomers, and (meth) acrylic esters, and the like. Examples of the unsaturated double bond-containing compound include olefin-based compounds having 2 to 12 carbon atoms (preferably 2 to 8), and examples thereof include ethylene, propylene, butene and the like. Examples of the vinyl-based cyclic hydrocarbon monomer include vinyl-based monomers such as 4-vinyl-cyclopentene and 2-methyl-4-isopropenyl-cyclopentene. Examples of (meth) acrylates include: alkyl (meth) acrylates having 1 to 20 carbon atoms such as methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and cyclohexyl (meth) acrylate.

The content of the cycloolefin monomer in the copolymer of the cycloolefin monomer and the copolymerizable monomer is preferably in the range of 20 to 80 mol%, more preferably in the range of 30 to 70 mol%, based on the total of all the monomers constituting the copolymer.

As described above, the cycloolefin resin is a polymer obtained by polymerizing or copolymerizing a cycloolefin monomer having a norbornene skeleton, preferably a cycloolefin monomer having a structure represented by the general formula (A-1) or (A-2), and examples thereof include the following polymers.

1) Ring-opened polymers of cycloolefin monomers

2) Ring-opened copolymer of cycloolefin monomer and copolymerizable monomer capable of ring-opening copolymerization with the same

3) The hydrogenated compound of the ring-opened (co) polymer of 1) or 2)

4) Cyclizing the ring-opened (co) polymer of 1) or 2) by Friedel Crafts reaction, and then carrying out hydrogenation to obtain (co) polymer

5) Saturated copolymers of cycloolefin monomers with compounds containing unsaturated double bonds

6) Addition copolymer of cycloolefin monomer and vinyl cyclic hydrocarbon monomer and hydrogenated product thereof

7) Alternating copolymers of cycloolefin monomers with (meth) acrylic esters

The polymers of 1) to 7) can be obtained by a known method, for example, the method described in Japanese patent application laid-open No. 2008-107534 and Japanese patent application laid-open No. 2005-227606. For example, the catalyst and solvent used in the ring-opening copolymerization of the above 2) may be, for example, the catalyst and solvent described in paragraphs 0019 to 0024 of Japanese patent application laid-open No. 2008-107534. The catalysts used in the hydrogenation of 3) and 6) may be, for example, the catalysts described in paragraphs 0025 to 0028 of Japanese patent application laid-open No. 2008-107534. The acidic compound used in the Friedel Crafts reaction of 4) may be, for example, an acidic compound described in paragraph 0029 of Japanese patent application laid-open No. 2008-107534. The catalyst used in the addition polymerization of 5) to 7) may be, for example, the catalyst described in paragraphs 0058 to 0063 of JP 2005-227606A. The alternating copolymerization reaction of 7) may be carried out by the method described in paragraphs 0071 and 0072 of Japanese patent application laid-open No. 2005-227606.

Among them, the polymers of 1) to 3) and 5) are preferable, and the polymers of 3) and 5) are more preferable. That is, from the viewpoint of being able to raise the glass transition temperature of the resulting cycloolefin resin and to improve the light transmittance, the cycloolefin resin preferably contains at least one of the structural unit represented by the following general formula (B-1) and the structural unit represented by the following general formula (B-2), more preferably contains only the structural unit represented by the general formula (B-2), or contains both the structural unit represented by the general formula (B-1) and the structural unit represented by the general formula (B-2). The structural unit represented by the general formula (B-1) is a structural unit derived from the cycloolefin monomer represented by the general formula (A-1), and the structural unit represented by the general formula (B-2) is a structural unit derived from the cycloolefin monomer represented by the general formula (A-2).

[ chemical formula 4]

General formula (B-1)

In the general formula (B-1), X represents-CH=CH-or-CH ₂ CH ₂ -。R ¹ ～R ⁴ And p is independently R of the formula (A-1) ¹ ～R ⁴ And p is synonymous.

[ chemical formula 5]

General formula (B-2)

In the general formula (B-2), X represents-CH=CH-or-CH =CH ₂ CH ₂ -。R ⁵ ～R ⁶ And p is independently R of the formula (A-2) ⁵ ～R ⁶ And p is synonymous.

The cycloolefin resin used in the present invention may be commercially available. Examples of commercial products of cycloolefin resins include: ARTON (registered trademark) G (e.g., G7810, etc.), ARTON F, ARTON R (e.g., R4500, R4900, R5000, etc.), and ARTON RX (e.g., RX4500, etc.), manufactured by JSR corporation.

Intrinsic viscosity [ eta ] of cycloolefin resin]inh is preferably 0.2 to 5cm in a measurement at 30 DEG C ³ In the range of/g, more preferably 0.3 to 3cm ³ In the range of/g, it is more preferably 0.4 to 1.5cm ³ In the range of/g.

The number average molecular weight (Mn) of the cycloolefin resin is preferably within a range of 8000 to 100000, more preferably within a range of 10000 to 80000, and even more preferably within a range of 12000 to 50000. The weight average molecular weight (Mw) of the cycloolefin resin is preferably in the range of 20000 to 300000, more preferably in the range of 30000 to 250000, and even more preferably in the range of 40000 to 200000. The number average molecular weight and the weight average molecular weight of the cycloolefin resin can be measured by Gel Permeation Chromatography (GPC) in terms of polystyrene.

< gel permeation chromatography >

Solvent: dichloromethane (dichloromethane)

Column: shodex K806, K805, K803G (3 pieces of Showa Denko K.K. C.used)

Column temperature: 25 DEG C

Sample concentration: 0.1 mass%

A detector: RI Model 504 (GL Science Co., ltd.)

And (3) a pump: l6000 (Hitachi manufacturing Co., ltd.)

Flow rate: 1.0mL/min

Calibration curve: calibration curves based on 13 samples of standard polystyrene STK standard polystyrene (manufactured by eash corporation) mw=500 to 2800000 were used. The 13 samples are preferably used at approximately equal intervals.

When the intrinsic viscosity [ η ] inh, the number average molecular weight and the weight average molecular weight are within the above-mentioned ranges, the cycloolefin resin is excellent in heat resistance, water resistance, chemical resistance, mechanical properties and molding processability as a resin film for a polarizing plate.

The cycloolefin resin has a glass transition temperature (Tg) of usually 110℃or higher, preferably 110 to 350℃and more preferably 120 to 250℃and still more preferably 120 to 220 ℃. By having a Tg of 110 ℃ or higher, deformation under high temperature conditions is easily suppressed. On the other hand, when the Tg is 350 ℃ or lower, molding processing is easy, and deterioration of the resin due to heat during molding processing is also easy to be suppressed.

The content of the cycloolefin resin is preferably 70 mass% or more, more preferably 80 mass% or more, relative to the total mass of the resin film for a polarizing plate.

< polycarbonate resin >

In the present invention, the polycarbonate resin is not particularly limited, but an aromatic polycarbonate resin is preferable in terms of chemical properties and physical properties, and a bisphenol a polycarbonate resin is particularly preferable. Among them, bisphenol A derivatives having benzene rings, cyclohexane rings, aliphatic hydrocarbon groups and the like introduced into bisphenol A are more preferably used. In addition, a polycarbonate resin having a structure in which the anisotropy in the unit molecule is reduced, which is obtained by introducing the derivative of the functional group asymmetrically with respect to the carbon in the center of bisphenol a, is particularly preferably used. As such a polycarbonate resin, particularly preferred is, for example, a polycarbonate resin obtained by using: a substance obtained by substituting 2 methyl groups in the central carbon of bisphenol A with benzene rings; one hydrogen of each benzene ring of bisphenol A is asymmetrically substituted with a methyl group, a phenyl group, or the like with respect to the central carbon.

Specifically, the substance obtained from 4,4 '-dihydroxydiphenyl alkane or a halogen substituent thereof by the phosgene method or the transesterification method includes, for example, 4' -dihydroxydiphenyl methane, 4 '-dihydroxydiphenyl ethane, 4' -dihydroxydiphenyl butane and the like. In addition, examples of the polycarbonate resin include those described in Japanese patent application laid-open No. 2006-215465, japanese patent application laid-open No. 2006-91836, japanese patent application laid-open No. 2005-121813, japanese patent application laid-open No. 2003-167121, japanese patent application laid-open No. 2009-126128, japanese patent application laid-open No. 2012-31369, japanese patent application laid-open No. 2012-67300, and International publication No. 00/26705.

The polycarbonate resin may be used in combination with a transparent resin such as a polystyrene resin, a methyl methacrylate resin, and a cellulose acetate resin. Further, a resin layer containing a polycarbonate resin may be laminated on at least one surface of a resin film formed using a cellulose acetate resin.

The polycarbonate resin preferably has a glass transition temperature (Tg) of 110 ℃ or higher and a water content (measured in water at 23 ℃ for 24 hours) of 0.3% or less. Further, tg of 120℃or higher and water content of 0.2% or less are more preferable.

(meth) acrylic resin)

In the present invention, the (meth) acrylic resin preferably contains at least a structural unit (U1) derived from methyl methacrylate and a structural unit (U2) derived from phenylmaleimide. The (meth) acrylic resin containing the structural unit (U2) derived from phenylmaleimide also has an advantage of reducing the photoelastic coefficient of the resin film for a polarizing plate, and is less likely to cause unevenness even if it swells with moisture absorption.

The (meth) acrylic resin may further contain other structural units than those described. Examples of such other building blocks include: alkyl (meth) acrylates such as adamantyl acrylate; cycloalkyl (meth) acrylates such as 2-ethylhexyl acrylate, and the like. Among them, from the viewpoint of reducing the brittle deterioration caused by the inclusion of the structural unit (U2) derived from phenylmaleimide, the structural unit (U3) derived from an alkyl acrylate is preferably further included.

That is, the (meth) acrylic resin more preferably contains a structural unit (U1) derived from methyl methacrylate, a structural unit (U2) derived from phenylmaleimide, and a structural unit (U3) derived from alkyl acrylate.

The content of the structural unit (U1) derived from methyl methacrylate is preferably in the range of 50 to 95 mass%, more preferably in the range of 70 to 90 mass%, relative to the total structural units constituting the (meth) acrylic resin.

Since the structural unit (U2) derived from phenylmaleimide has a relatively rigid structure, the mechanical strength of the resin film for a polarizing plate can be improved. In addition, the structural unit (U2) derived from phenylmaleimide has a structure with a large steric hindrance, and has minute voids in the resin matrix where rubber particles can move. Therefore, the rubber particles are likely to be locally present in the surface layer portion of the resin film for a polarizing plate.

The content of the structural unit (U2) derived from phenylmaleimide is preferably in the range of 1 to 25 mass% relative to the total structural units constituting the (meth) acrylic resin. The content of the structural unit (U2) derived from phenylmaleimide is 1 mass% or more, whereby the resin film for a polarizing plate is excellent in storage stability in a high humidity environment. Further, the brittleness of the resin film for a polarizing plate is not easily impaired excessively by 25 mass% or less. From the standpoint of the above, the content of the structural unit (U2) derived from phenylmaleimide is more preferably in the range of 7 to 15 mass%.

The structural unit (U3) derived from an alkyl acrylate can impart moderate flexibility to the resin, and thus can improve brittleness caused by, for example, inclusion of the structural unit (U2) derived from phenylmaleimide.

The alkyl acrylate is preferably an alkyl acrylate having 1 to 7 carbon atoms in the alkyl moiety, preferably 1 to 5 carbon atoms. Examples of the alkyl acrylate include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, 2-hydroxyethyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, and the like.

The content of the structural unit (U3) derived from the alkyl acrylate is preferably in the range of 1 to 25 mass% relative to the total structural units constituting the (meth) acrylic resin. By setting the content of the structural unit (U3) derived from the alkyl acrylate to 1 mass% or more, a proper flexibility can be imparted to the (meth) acrylic resin, and therefore the resin film for a polarizing plate does not become excessively brittle and is less likely to break. Further, when the content is 25 mass% or less, tg of the resin film for a polarizing plate does not become too low, and the resin film for a polarizing plate is excellent in storage stability under a high humidity environment. From the standpoint of the above, the content of the structural unit (U3) derived from the alkyl acrylate is more preferably in the range of 5 to 15 mass%.

The ratio of the structural unit (U2) derived from phenylmaleimide to the total amount of the structural unit (U2) derived from phenylmaleimide and the structural unit (U3) derived from alkyl acrylate is preferably in the range of 20 to 70 mass%. When the proportion is 20% by mass or more, the tensile elastic modulus G2 of the resin film for a polarizing plate is easily increased, and when the proportion is 70% by mass or less, the resin film for a polarizing plate is not excessively brittle.

The glass transition temperature (Tg) of the (meth) acrylic resin is preferably 100℃or higher, more preferably in the range of 120 to 150 ℃. When the Tg of the (meth) acrylic resin is within the above range, the heat resistance of the resin film for a polarizing plate can be easily improved. In order to adjust Tg of the (meth) acrylic resin, for example, y preferably adjusts the content of the structural unit (U2) derived from phenylmaleimide and the structural unit (U3) derived from alkyl acrylate.

The weight average molecular weight (Mw) of the (meth) acrylic resin is not particularly limited and may be adjusted according to the purpose. The weight average molecular weight of the (meth) acrylic resin is preferably 10 ten thousand or more, more preferably 100 ten thousand or more, from the viewpoint of promoting entanglement of resin molecules with each other, improving toughness of the resin film for a polarizing plate, and preventing breakage, and from properly increasing the coefficient of humidity expansion (also referred to as "CHE ratio") and easily adjusting the amount of curl to a degree preferable for adhesion. By setting the weight average molecular weight of the (meth) acrylic resin to 100 ten thousand or more, the toughness of the obtained resin film for a polarizing plate can be improved. This makes it possible to suppress breakage of the resin film for a polarizing plate due to the conveyance tension when the resin film for a polarizing plate is conveyed to the laminated film, and to improve the conveyance stability. From the same viewpoint, the weight average molecular weight of the (meth) acrylic resin is more preferably in the range of 150 to 300 ten thousand. The method for measuring the weight average molecular weight is as described above.

< styrene- (meth) acrylate copolymer >

In the present invention, a resin film for a polarizing plate having excellent transparency can be obtained by using a styrene- (meth) acrylate copolymer (hereinafter also referred to as a styrene-acrylic resin). Further, since the humidity expansion coefficient can be adjusted by the copolymerization ratio of the styrene moiety, the curl of the polarizing plate of the present invention can be controlled by changing the ratio thereof.

The styrene-acrylic resin is formed by addition-polymerizing at least a styrene monomer and a (meth) acrylate monomer. Styrene monomer except CH ₂ ＝CH-C ₆ H ₅ In addition to styrene represented by the structural formula (I), the styrene derivative having a known side chain or functional group in the styrene structure is also included.

In addition, (meth) acrylate monomers other than CH (R) ₁ )＝CHCOOR ₂ (R ₁ Represents a hydrogen atom or a methyl group, R ₂ Alkyl groups having 1 to 24 carbon atoms), and also acrylate derivatives and methacrylate derivatives having known side chains and functional groups in the structures of these esters.

Examples of the styrene monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α -methylstyrene, p-phenylstyrene, p-ethylstyrene, 2, 4-dimethylstyrene, p-t-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene and p-n-dodecylstyrene.

Examples of the (meth) acrylic acid ester monomer include acrylic acid ester monomers such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate (2 EHA), stearyl acrylate, lauryl acrylate, and phenyl acrylate; methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate and other methacrylates.

In the present specification, "(meth) acrylate monomer" is a generic term for "acrylate monomer" and "methacrylate monomer" and means one or both of them. For example, "(meth) acrylic acid methyl ester" means one or both of "acrylic acid methyl ester" and "methacrylic acid methyl ester".

The (meth) acrylate monomer may be used singly or in combination of two or more. For example, a copolymer may be formed using a styrene monomer and two or more acrylate monomers, a copolymer may be formed using a styrene monomer and two or more methacrylate monomers, and a copolymer may be formed using a styrene monomer in combination with an acrylate monomer and a methacrylate monomer.

The weight average molecular weight (Mw) of the styrene-acrylic resin is preferably in the range of 5000 to 150000, more preferably in the range of 30000 to 120000, from the viewpoint of easy control of moldability.

The styrene-acrylic resin used in the present invention may be commercially available, and as an example, MS resin "TX320XL" manufactured by DENKA Co., ltd.

< fumaric acid diester resin >)

In the present invention, the fumaric acid diester resin is a fumaric acid diester resin containing a diisopropyl fumarate residue unit and a fumaric acid diester residue unit having an alkyl group having 1 or 2 carbon atoms.

The alkyl group having 1 or 2 carbon atoms in the fumaric acid diester residue unit having 1 or 2 carbon atoms is independently, and examples thereof include a methyl group and an ethyl group. In addition, they may be substituted with halogen groups such as fluorine, chlorine, etc.; an ether group; an ester group or an amino group. Examples of the fumaric acid diester residue unit having an alkyl group having 1 or 2 carbon atoms include: dimethyl fumarate residue units and diethyl fumarate residue units. Furthermore, they may contain one or two or more.

Specific examples of the fumaric acid diester resin include: diisopropyl fumarate/dimethyl fumarate copolymer resins, diisopropyl fumarate/diethyl fumarate copolymer resins, and the like.

The fumaric acid diester resin may contain other monomer residue units as long as the content does not exceed the scope of the present invention, and examples of the other monomer residue units include: a styrene residue unit selected from a styrene residue unit, an α -methylstyrene residue unit and the like; (meth) acrylic acid residue units; methyl (meth) acrylate residue units, ethyl (meth) acrylate residue units, butyl (meth) acrylate residue units, and the like; vinyl ester residue units such as vinyl acetate residue units and vinyl propionate residue units; an acrylonitrile residue unit; methacrylonitrile residue units; vinyl ether residue units such as methyl vinyl ether residue units, ethyl vinyl ether residue units, and butyl vinyl ether residue units; n-substituted maleimide-based residue units such as N-methylmaleimide residue units, N-cyclohexylmaleimide residue units and N-phenylmaleimide residue units; an olefinic residue unit such as an ethylene residue unit and a propylene residue unit; or at least one of a fumaric acid diester residue other than the fumaric acid diester residue unit, such as a di-n-butyl fumarate residue unit and a bis (2-ethylhexyl) fumarate residue unit, and cinnamic acid and a cinnamic acid ester unit.

The blending ratio of the fumaric acid diester resin used in the present invention is preferably 50 to 99 mol% of the diisopropyl fumarate residue unit and 1 to 50 mol% of the fumaric acid diester residue unit having an alkyl group having 1 or 2 carbon atoms, and particularly preferably 5 to 40 mol% of the diisopropyl fumarate residue unit and the fumaric acid diester residue unit having an alkyl group having 1 or 2 carbon atoms, from the viewpoints of retardation characteristics and strength when a retardation film is produced.

The fumaric acid diester resin used in the present invention preferably has a number average molecular weight in the range of 50000 to 250000 in terms of standard polystyrene obtained from an elution profile measured by the gel permeation chromatography.

(Synthesis example of fumaric acid diester resin)

In a 1L autoclave equipped with a stirrer, a cooling tube, a nitrogen inlet tube and a thermometer, 2g of hydroxypropyl methylcellulose (trade name: METOLOSE 60SH-50, manufactured by Xinyue chemical Co., ltd.), 600g of distilled water, 330g of diisopropyl fumarate, 70g of diethyl fumarate and 3g of t-butyl peroxypivalate as a polymerization initiator were placed, and after bubbling of nitrogen gas for 1 hour, the mixture was stirred at 400rpm and kept at 50℃for 24 hours, whereby radical suspension polymerization was carried out. Cooled to room temperature, and the suspension containing the polymer particles thus produced was separated by filtration and washed with distilled water and methanol to obtain a fumaric acid diester resin (yield: 75%).

The number average molecular weight of the obtained fumaric acid diester resin was 120000. Further, the resin composition was found to be diisopropyl fumarate residue unit/diethyl fumarate residue unit=84/16 (mol%) by 1H-NMR measurement.

< polyarylate resin >

In the present invention, a film excellent in toughness can be obtained by using a polyarylate resin. The polyarylate resin comprises at least a structural unit derived from an aromatic diol and a structural unit derived from an aromatic dicarboxylic acid.

The polyarylate resin used in the present invention may be commercially available, and examples thereof include PAR resin "U-100" manufactured by UNITKA Co., ltd., and "weight average molecular weight (Mw) 100000".

[1.2 inhibitor of iodine movement ]

In the present invention, the "iodine migration inhibitor" refers to a chemical material having a function of physically inhibiting migration of iodine, and includes a heat-dissipating material and a charge-repulsive material.

The heat radiation material is a material that is actively moved to suppress the absorption of heat energy by multi-iodine, and that facilitates the heat radiation in the polarizer layer.

The charge-repellent material is a material that causes charge-repellent action on multi-iodine having a charge, thereby preventing movement of iodine.

[1.2.1 Heat-dissipating Material ]

The heat-dissipating material is not particularly limited as long as it has high thermal conductivity and can improve the thermal conductivity of the resin film for a polarizing plate of the present invention. Examples thereof include polymethyl methacrylate (PMMA), polycarbonate, glass, silicone rubber, diamond-like carbon (DLC), aluminum nitride, silicon nitride, boron nitride, magnesium nitride, silicon carbide, aluminum oxide, silicon oxide, zinc oxide, magnesium oxide, and the like. Among them, metal oxide particles are preferable from the viewpoint of thermal conductivity. In addition, transparent particles are preferably used from the viewpoint of not impairing the transparency of the resin film for a polarizing plate.

The thermal conductivity of the resin film for a polarizing plate containing the heat-dissipating material as an iodine migration inhibitor is preferably in the range of 0.2 to 0.6W/m·k. In the above-described range, in the display device having the polarizing plate provided with the resin film for a polarizing plate of the present invention, even if the polarizer layer generates heat with use and even if heat is transferred to the polarizer layer due to the heat generation of the semiconductor substrate, the resin film for a polarizing plate has high thermal conductivity, that is, the resin film for a polarizing plate has heat dissipation properties, so that heat is not easily transferred to iodine at most, and movement of iodine due to heat can be suppressed. The resin film for a polarizing plate has sufficient heat dissipation properties when the thermal conductivity is 0.2W/m·k or more, and is less likely to cause defects in the display device due to a temperature difference from other components when the thermal conductivity is 0.6W/m·k or less.

The thermal conductivity of the resin film of the present invention can be measured as follows.

The resin film was sandwiched between the TO-3 type heater case and the copper plate, compressing 10% of the film thickness. Then, a power of 5W was applied to the copper heater case and the copper heater case was held for 4 minutes, and the temperature difference between the copper heater case and the copper plate was measured. The thermal conductivity can be calculated by the following formula.

Thermal conductivity { W/m.K = { power (W) ×thickness (m) }/{ temperature difference (K) ×measurement area (m) ² )}

[1.2.1.1 Metal oxide particles ]

In the present invention, the heat-dissipating material is preferably metal oxide particles from the viewpoint of facilitating adjustment of the thermal conductivity of the resin film for a polarizing plate to the above-described preferable range. Examples of the metal oxide particles include aluminum oxide, silicon oxide, zinc oxide, magnesium oxide, titanium oxide, and the like. They may be surface-treated with a silane coupling agent or the like.

As the metal oxide particles used in the present invention, commercially available products can be used, and examples of commercially available products of alumina include the trade names "AS-50" (manufactured by Showa electric company), the trade name "AL-13KT" (average particle size 96 μm) (manufactured by Showa electric company), and the like. Examples of the commercial products of zinc oxide include a trade name "SnO-310" (manufactured by sumitomo osaka cement corporation), a trade name "SnO-350" (manufactured by sumitomo osaka cement corporation), a trade name "SnO-410" (manufactured by sumitomo osaka cement corporation), and the like.

In the present invention, the term "primary particles" is used as a generic term for a substance (referred to as "aggregate") constituting a crystal and a strong aggregate in which the crystal shares a specific surface. The particle aggregate (referred to as an "aggregate") formed by agglomerating the primary particles is referred to as "secondary particles". "

In the present invention, the average primary particle diameter (particle diameter of the primary particles) and the average secondary particle diameter (particle diameter of the secondary particles) are defined as follows.

In a sample prepared by the microtome, primary particles (or secondary particles) are observed by a transmission electron microscope (for example, hitachi H-7100FA type), and the diameter (so-called equivalent circle diameter) at which a circle having the same projected area is assumed is taken as the primary particle diameter (or secondary particle diameter). Then, the particle diameters of 1000 primary particles (or secondary particles) thus obtained were averaged, and the average value thereof was regarded as an average primary particle diameter (or average secondary particle diameter).

The average primary particle diameter of the metal oxide particles is preferably in the range of 50 to 100nm, more preferably about 80 nm. The average secondary particle diameter is preferably 1000nm or more, more preferably 1200nm or more. The particles may be spherical or needle-like in shape.

The ratio of the average primary particle diameter to the average secondary particle diameter of the metal oxide particles preferably satisfies the following formula.

20< average secondary particle diameter/average primary particle diameter <2000

The metal oxide particles of the present invention absorb the thermal energy of the polarizer layer and propagate the thermal energy to adjacent particles, thereby realizing a heat dissipation function. In the resin film for a polarizing plate of the present invention, the metal oxide particles are separated from each other by the thermoplastic resin having low thermal conductivity, and therefore it is difficult to transmit heat energy. Therefore, by appropriately forming the metal oxide particles into aggregates, the particles are in contact with each other, and therefore, thermal energy can be further propagated, so that the heat dissipation function is improved.

By making the ratio of the average primary particle diameter to the average secondary particle diameter of the metal oxide particles to exceed 20, a sufficient heat dissipation function can be obtained. The larger the ratio, the more preferably the smaller the ratio is, the more preferably the temperature difference between the respective members in the display device is not excessively large, and deterioration and defects of the display device can be prevented. The ratio of the average primary particle diameter to the average secondary particle diameter of the metal oxide particles can be controlled by dispersing the metal oxide particles.

The content of the heat dissipating material is preferably in the range of 5 to 50 mass% relative to the total mass of the thermoplastic resin. When the content is 5 mass% or more, sufficient thermal conductivity can be obtained, and when the content is 50 mass% or less, sufficient strength can be obtained in terms of productivity.

[1.2.2 Charge-repulsive Material ]

As charge repulsionThe material is not particularly limited as long as it is a material that prevents movement of iodine by charge repulsion against multi-iodine having charges. From and with polyiodides (I) ₃ ^- Or I ₅ ^- ) From the viewpoint of charge repulsion, a compound having negative charge or a compound having negative polarity is preferable as such a charge repulsive material.

[1.2.2.1 non-organic acids ]

In the present invention, the charge-repellent material is preferably a non-organic acid from the viewpoint that the reaction product resulting from neutralization with polyiodine is not likely to precipitate. In the present invention, the non-organic acid means an organic compound having 5 or more carbon atoms and having no proton donor group such as a carboxylic acid group or a sulfonic acid group. From the viewpoint of low and stable reactivity even when the charge is not uniform, an organic compound having 15 or more carbon atoms is more preferable. The non-organic acid having polarity is not particularly limited, and examples thereof include anionic surfactants, anionic ligands, triphenylmethane derivatives, barbituric acid compounds, and the like.

The molecular weight of the non-organic acid is preferably in the range of 200 to 1000, more preferably in the range of 250 to 800, still more preferably in the range of 280 to 600. By setting the molecular weight to 200 or more, disappearance due to volatilization of the non-organic acid at the time of film formation of the resin film for a polarizing plate can be suppressed. Further, by setting the content to 1000 or less, the compatibility of the thermoplastic resin contained in the film with the non-organic acid is good, and a film with low haze can be obtained.

The Hansen solubility parameter (HSP value) of the non-organic acid is preferably 5 to 9MPa in terms of δP (polar force) ^0.5 Within a range of (2). By making δP 5MPa ^0.5 As described above, the non-organic acid sufficiently performs charge repulsion with the multi-iodine. By making δP 9MPa ^0.5 Hereinafter, the resin has affinity to the resin, and bleeding is suppressed. Further, by setting the repulsive force to a proper value, the orientation of the multi-iodine in the polarizer layer can be maintained. The hansen solubility parameter will be described in detail later.

< anionic surfactant >

The anionic surfactant is not particularly limited, but is preferably a surfactant having a long-chain alkyl group, and more preferably a surfactant having an alkyl group having 6 to 20 carbon atoms.

As an example, as the sulfate salt type, there may be mentioned: sodium lauryl sulfate, sodium hexyl sulfate, sodium heptyl sulfate, sodium octyl sulfate, sodium nonyl sulfate, sodium decyl sulfate, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium hexadecyl sulfate, sodium octadecyl sulfate, sodium eicosyl sulfate, or alkyl sulfate salts such as potassium salts, calcium salts, and ammonium salts thereof, sodium polyoxyethylene hexyl ether sulfate, sodium polyoxyethylene heptyl ether sulfate, sodium polyoxyethylene octyl ether sulfate, sodium polyoxyethylene nonyl ether sulfate, sodium polyoxyethylene decyl ether sulfate, sodium polyoxyethylene dodecyl ether sulfate, sodium polyoxyethylene tetradecyl ether sulfate, sodium polyoxyethylene cetyl ether sulfate, sodium polyoxyethylene octadecyl ether sulfate, sodium polyoxyethylene eicosyl ether sulfate, or polyoxyethylene alkyl ether sulfate such as potassium salts, ammonium salts thereof, sodium polyoxyethylene hexyl phenyl ether sulfate, sodium polyoxyethylene heptyl phenyl ether sulfate, sodium polyoxyethylene octyl ether sulfate, sodium polyoxyethylene nonyl ether sulfate, sodium polyoxyethylene decyl ether sulfate, sodium polyoxyethylene dodecyl ether sulfate, sodium polyoxyethylene cetyl ether sulfate, sodium polyoxyethylene stearyl ether sulfate, sodium polyoxyethylene eicosyl ether sulfate, sodium polyoxyethylene heptyl phenyl ether sulfate, sodium polyoxyethylene hexyl phenyl ether sulfate, sodium polyoxyethylene heptyl ether sulfate, sodium salt, and the like sodium polyoxyethylene octylphenyl ether sulfate, sodium polyoxyethylene nonylphenyl ether sulfate, sodium polyoxyethylene decylphenyl ether sulfate, sodium polyoxyethylene dodecylphenyl ether sulfate, sodium polyoxyethylene tetradecylphenyl ether sulfate, sodium polyoxyethylene hexadecylphenyl ether sulfate, sodium polyoxyethylene octadecylphenyl ether sulfate, sodium polyoxyethylene eicosylphenyl ether sulfate, or polyoxyethylene alkylphenyl ether sulfate such as potassium salt and ammonium salt thereof, sodium caproate ethanolamide sulfate, sodium caprylate ethanolamide sulfate, sodium caprate ethanolamide sulfate, sodium laurate ethanolamide sulfate, sodium palmitate ethanolamide sulfate, sodium stearate ethanolamide sulfate, sodium oleate ethanolamide sulfate or potassium salt thereof, propanol amide substituted with these ethanolamides, higher fatty acid alkanolamide sulfate such as butanolamide, etc, sulfated oils, higher alcohol ethoxy sulfates, monoethylene glycol sulfates, and the like.

Besides the sulfate salt type, there may be mentioned: fatty acid soaps such as sodium oleate and castor oil potassium soap, salts thereof, polyoxyethylene alkyl ester carboxylates, carboxylates such as acylated peptides, sodium hexyl sulfonate, sodium heptyl sulfonate, sodium octyl sulfonate, sodium nonyl sulfonate, sodium decyl sulfonate, sodium dodecyl sulfonate, sodium tetradecyl sulfonate, sodium cetyl sulfonate, sodium octadecyl sulfonate, a mixture of sodium aliphatic alkyl sulfonates having 6 to 18 carbon atoms, alkylbenzene sulfonate, alkyl naphthalene sulfonate, formalin polycondensates of salts of naphthalene sulfonic acid, formalin condensates of salts of melamine sulfonic acid, salts of dialkyl sulfosuccinates, alkenyl succinates, alkyl sulfosuccinates, polyoxyethylene alkyl sulfosuccinates, alkyl sulfoacetates, sulfonates such as alpha-olefin sulfonate, N-acyl methyl taurates, dimethyl-5-sulfoisophthalate sodium salt, polyoxyethylene alkyl ether phosphate, polyoxyethylene alkylphenyl ether phosphate, phosphate of phosphate esters such as alkyl phosphate, and the like.

Examples of the anionic surfactant that can be used include ELECUT (registered trademark) S-412-2 manufactured by Bambusa oil and fat Co., ltd., ELECTROSR IPPER (registered trademark) F manufactured by Kabushiki Kaisha, and the like.

< anionic ligand >

The anionic ligand in the present invention is an anionic ligand capable of forming a complex with a transition metal ion of valence 2 (e.g., cobalt (II), nickel (II), copper (II), iron (II), zinc (II), etc.).

As the anionic ligand, compounds represented by the following general formulae (L1) to (L3) can be preferably used. In any of the compounds, the number of carbon atoms is 5 or more.

[ chemical formula 6]

General formula (L1)

Wherein R is ₁ 、R ₂ 、R ₃ R is R ₄ Each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, X ₁ represent-NR ₅ R ₆ 、OR ₇ 、SR ₈ (R ₅ 、R ₆ 、R ₇ R is R ₈ Respectively represent a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group). n represents 0 or 1. In addition, R ₁ And R is R ₃ Can be directly bonded to form a double bond, or R ₁ 、R ₂ 、R ₃ 、R ₄ 、X ₁ Form a ring.

As R ₁ ～R ₄ Examples of the alkyl group include: examples of cycloalkyl groups include methyl, ethyl, isopropyl, t-butyl, dodecyl, and 1-hexylnonyl: cyclopropyl, cyclohexyl, bicyclo [2.2.1]Examples of the aryl group include phenyl, o-tolyl, o-anisyl, 1-naphthyl and 9-anthracenyl.

These alkyl groups, cycloalkyl groups, aryl groups may have a substituent. Examples of the substituent include: straight-chain or branched alkyl (methyl, ethyl, isopropyl, t-butyl, dodecyl, 1-hexylnonyl, etc.), cycloalkyl (cyclopropyl, cyclohexyl, bicyclo [2.2.1] heptyl, adamantyl, etc.), alkenyl (2-propylene, oleyl, etc.), aryl (phenyl, o-tolyl, o-anisyl, 1-naphthyl, 9-anthracenyl, etc.), heterocyclyl (2-tetrahydrofuranyl, 2-thienyl, 4-imidazolyl, 2-pyridyl, etc.), halogen atom (fluorine, chlorine, bromine, etc.), cyano, nitro, alkylcarbonyl (acetyl, pivaloyl, etc.), arylcarbonyl (benzoyl, pentafluorobenzoyl, 3, 5-di-t-butyl-4-hydroxybenzoyl, etc.), oxycarbonyl (methoxycarbonyl, cyclohexyloxycarbonyl, etc.), aryloxycarbonyl, such as dodecyloxycarbonyl, phenoxycarbonyl, 2, 4-di-t-pentylphenoxycarbonyl, 1-naphthyloxycarbonyl, etc.), heterocyclyloxycarbonyl (2-pyridyloxycarbonyl, 1-phenylpyrazolyl-5-oxycarbonyl, etc.), carbamoyl (di-t-carbamoyl, etc.), carbamoyl (carbamoyl, 4-carbamic, etc.), dicarbamoyl, etc.), aryloxycarbonyl (carbamoyl, 2-t-butyloxycarbonyl, 4-carbamic, etc.), aryloxy (carbamoyl, etc.), aryloxycarbonyl, etc, 4- (4-hydroxyphenylsulphonyl) phenoxy, etc.), heterocyclyloxy (4-pyridyloxy, 2-hexahydropyranyloxy (2-N), etc.), carbonyloxy (acetyloxy, trifluoroacetyloxy, alkylcarbonyloxy such as pivaloyloxy, etc.), benzoyloxy, aryloxy such as pentafluorobenzoyloxy, etc.), carbamate (alkylcarbamate such as N, N-dimethylcarbamate, etc., arylcarbamate such as N-phenylcarbamate, N- (p-cyanophenyl) carbamate, etc.), alkylsulfonyloxy (arylsulfonyloxy such as methanesulfonyloxy, trifluoromethanesulfonyloxy, dodecylsulfonyloxy, etc.), alkylsulfonyloxy such as benzenesulfonyloxy, arylsulfonyloxy such as p-toluenesulfonyloxy, etc.), amino (dimethylamino, cyclohexylamino, dodecylamino, etc.; arylamino groups such as anilino group, p-tert-octylanilino group, alkylsulfonylamino groups such as methanesulfonylamino group, heptafluoropropanesulfonylamino group and hexadecylsulfonylamino group, arylsulfonylamino groups such as p-toluenesulfonylamino group and pentafluorobenzenesulfonylamino group, alkylsulfonylamino groups such as sulfamoylamino group (N, N-dimethylsulfamoylamino group, arylsulfonylamino groups such as N-phenylsulfamoylamino group), acylamino groups (alkylcarbonylamino groups such as acetylamino group and myristoylamino group, alkylcarbonylamino groups such as benzoylamino group), ureido groups (N, N-dimethylsemicarbazide group, alkylureido groups such as N-phenylureido group, N- (p-cyanophenyl) ureido group, alkylsulfonyl groups such as methanesulfonyl group and trifluoromethylsulfonyl group, alkylsulfonyl groups such as p-toluenesulfonyl group, alkylsulfamoyl groups such as 4- (2, 4-di-tert-pentylphenoxy) butylsulfamoyl group, phenylsulfamoyl group such as phenylsulfamoyl group, phenylsulfamoyl group such as 4- (2, 4-di-tert-pentylphenyl) and phenylsulfamoyl group (such as 5-methylsulfonyl group), and heterocycle (such as 5-methylsulfonyl group).

[ chemical formula 7]

General formula (L2)

Wherein R is ₉ Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, a thioether group or an amino group, X ₂ X is X ₃ Respectively represent-NR ₁₀ -, -O-, -S-or-CR ₁₁ (R ₁₂ )-(R ₁₀ 、R ₁₁ R is R ₁₂ Respectively represent a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group or an amino group), and B represents an oxygen atom or a sulfur atom. In addition, R can also be ₉ And X is ₂ 、R ₉ And X is ₃ Or X ₂ And X is ₃ Forming a ring.

R ₉ ～R ₁₂ Alkyl, cycloalkyl, aryl, alkoxy, aryloxy and amino groups as shown and R ₁ ～R ₄ The meaning of the substitutable groups in (a) is the same. As R ₉ Examples of the thioether group include alkylthio (methylthio, t-octylthio and the like), arylthio (phenylthio and the like), heterocyclylthio (1-phenyltetrazol-5-thio, 5-methyl-1, 3, 4-oxadiazol-2-thio and the like) and the like.

As can be represented by R ₉ And X is ₂ 、R ₉ And X is ₃ Or X ₂ And X is ₃ Examples of the ring to be formed include a 5-to 7-membered carbocyclic ring and a 5-to 6-membered heterocyclic ring.

[ chemical formula 8]

General formula (L3)

Wherein R is ₁₃ 、R ₁₄ R is R ₁₅ Each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, a heterocyclic group, an alkoxy group or an amino group, X ₄ represent-NR ₁₆ -, -O-or-S-. R is R ₁₆ Represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group or an amino group. Wherein X is ₄ When oxygen, R ₁₃ And R is ₁₄ Form an aromatic ring, and R ₁₅ Not methyl.

R ₁₃ ～R ₁₆ Alkyl, cycloalkyl and aryl as shown and R ₁ ～R ₄ The meaning is the same. X is X ₄ In the case of oxygen, R is ₁₃ And R is ₁₄ Examples of the aromatic ring include benzene, naphthalene, pyridine, furan, indole, thiazole ring and the like.

The following will describe specific examples of the compounds represented by the general formulae (L1) to (L3), but the present invention is not limited to the following specific examples.

[ chemical formula 9]

[ chemical formula 10]

[ chemical formula 11]

/>

[ chemical formula 12]

[ chemical formula 13]

[ chemical formula 14]

[ chemical formula 15]

[ chemical formula 16]

[ chemical formula 17]

These compounds can be synthesized by the method described in chelate chemistry (5) complex chemistry experiments [ I ] (code of Nanno Jiang Tang), and the like. Representative synthesis examples are shown below.

(Synthesis of L3-14)

17.8g of nickel acetate was dissolved in 100ml of water, and a solution of 15.0g of dodecyl salicylate in 45ml of acetonitrile was added dropwise. Stirred under ice-cooling for 5 hours, and the precipitated solid was collected by filtration. The structure was determined by NMR spectroscopy and IR spectroscopy.

< triphenylmethane derivative >

As the triphenylmethane derivative, a compound represented by the following general formula (C) can be preferably used.

[ chemical formula 18]

General formula (C)

(wherein X represents an amino group, an acylamino group, an alkoxycarbonylamino group, an aryloxycarbonylamino group, a sulfonylamino group, a hydroxyl group, a mercapto group, a carbamoyl group, an arylaminocarbonyl group or a carboxyl group, which may have a substituent.

R ¹¹ ～R ¹⁵ 、R ²¹ ～R ²⁵ 、R ³¹ ～R ³⁵ Each independently represents a hydrogen atom or a substituent. R is R ¹¹ And R is ²¹ 、R ¹⁵ And R is ³⁵ Or R ²⁵ And R is ³¹ The bonding may be via a single bond or a 2-valent linking group. )

X is preferably an amino group or a hydroxyl group, more preferably a hydroxyl group.

R ¹¹ ～R ¹⁵ 、R ²¹ ～R ²⁵ 、R ³¹ ～R ³⁵ Each independently represents a hydrogen atom or a substituentAs the substituent, the following substituent T may be used.

Examples of the substituent T include an alkyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 12 carbon atoms, still more preferably having 1 to 8 carbon atoms, such as methyl, ethyl, isopropyl, tert-butyl, n-octyl, n-decyl, n-hexadecyl, cyclopropyl, cyclopentyl, cyclohexyl and the like), an alkenyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, still more preferably having 2 to 8 carbon atoms, such as vinyl, allyl, 2-butenyl, 3-pentenyl and the like), an alkynyl group (preferably having 2 to 20 carbon atoms, more preferably having 2 to 12 carbon atoms, still more preferably having 2 to 8 carbon atoms, such as propargyl, 3-pentynyl and the like), an aryl group (preferably having 6 to 30 carbon atoms, more preferably having 6 to 20 carbon atoms, still more preferably having 6 to 12 carbon atoms, such as phenyl, p-methylphenyl, naphthyl and the like), a substituted or unsubstituted amino group (preferably having 0 to 20 carbon atoms, more preferably having 0 to 10 carbon atoms, still more preferably having 0 to 6 carbon atoms, such as methyl amino, di-methylamino, 2 to 12 carbon atoms, preferably having 1 to 16 carbon atoms, etc.), an aryloxy group (preferably having 1 to 12 carbon atoms, more preferably having 1 to 20 carbon atoms, such as methoxy, 3-pentynyl and the like), an aryl group (preferably having 6 to 30 carbon atoms, 6 to 20 carbon atoms, more preferably having 6 to 20 carbon atoms, 6 to 12 carbon atoms, etc.) (preferably having 6 to 16 carbon atoms, such as benzyl, etc.), more preferably 1 to 12 carbon atoms, for example, acetyl group, benzoyl group, formyl group, pivaloyl group and the like), alkoxycarbonyl group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, further preferably 2 to 12 carbon atoms, for example, methoxycarbonyl group, ethoxycarbonyl group and the like), aryloxycarbonyl group (preferably 7 to 20 carbon atoms, more preferably 7 to 16 carbon atoms, further preferably 7 to 10 carbon atoms, for example, phenoxycarbonyl group and the like), acyloxy group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, further preferably 2 to 10 carbon atoms, for example, acetoxy group, benzoyloxy group and the like), acylamino group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, further preferably 2 to 10 carbon atoms, for example, acetylamino group, benzoylamino group and the like), alkoxycarbonylamino group (preferably 2 to 20 carbon atoms, more preferably 2 to 16 carbon atoms, further preferably 2 to 12 carbon atoms, for example, methoxycarbonylamino group and the like).

In addition, an aryloxycarbonylamino group (preferably having 7 to 20 carbon atoms, more preferably having 7 to 16 carbon atoms, still more preferably having 7 to 12 carbon atoms, for example, phenoxycarbonylamino group and the like), a sulfonylamino group (preferably having 1 to 20 carbon atoms, still more preferably having 1 to 12 carbon atoms, for example, methanesulfonylamino group, benzenesulfonylamino group and the like), a sulfamoyl group (preferably having 0 to 20 carbon atoms, still more preferably having 0 to 16 carbon atoms, still more preferably having 0 to 12 carbon atoms, for example, sulfamoyl group, methylsulfamoyl group, dimethylsulfamoyl group, phenylsulfamoyl group and the like), a carbamoyl group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, for example, 1 to 12 carbon atoms, for example, carbamoyl group, methylcarbamoyl group, diethylcarbamoyl group, phenylcarbamoyl group and the like), an alkylthio group (preferably having 1 to 20 carbon atoms, more preferably having 1 to 16 carbon atoms, further preferably having 1 to 16 carbon atoms, for example, further preferably having 1 to 12 carbon atoms, for example, methylsulfinyl group, preferably having 1 to 16 carbon atoms, 6 carbon atoms, for example, preferably having 1 to 16 carbon atoms, 6 carbon atoms, etc.), an arylsulfonyl group, for example, more preferably having 1 to 16 carbon atoms, 6 to 16 carbon atoms, and the like, urea group (preferably 1 to 20 carbon atoms, more preferably 1 to 16 carbon atoms, still more preferably 1 to 12 carbon atoms, for example, urea group, methylurea group, phenylurea group and the like), phosphoric acid amide group (preferably 1 to 20 carbon atoms, still more preferably 1 to 12 carbon atoms, for example, diethylphosphoric acid amide, phenylphosphoric acid amide and the like), hydroxyl group, mercapto group, halogen atom (for example, fluorine atom, chlorine atom, bromine atom, iodine atom), cyano group, sulfo group, carboxyl group, nitro group, hydroxamic acid group, sulfinyl group (preferably 1 to 30 carbon atoms, more preferably 1 to 12 carbon atoms, for example, nitrogen atom, oxygen atom, sulfur atom, for example, imidazole group, pyridyl group, quinoline group, furan group, piperidine group, morpholino group, benzoxazolyl group, benzimidazole group, benzothiazolyl and the like), silyl group (preferably 3 to 40 carbon atoms, more preferably 3 to 30 carbon atoms, more preferably 3 to 24 carbon atoms, for example, trimethylsilyl group and the like, and the like can be exemplified as hetero atom. Of these, alkyl, aryl, substituted or unsubstituted amino, alkoxy, and aryloxy groups are more preferable, and alkyl, aryl, and alkoxy groups are further preferable.

These substituents may be further substituted with a substituent T. In addition, when two or more substituents are used, they may be the same or different. Furthermore, rings may also be formed by joining together, where possible.

The compounds of the general formula (C) are commercially available or can be synthesized by known methods.

The compound represented by the general formula (C) will be described in detail below with reference to specific examples, but the present invention is not limited to the following specific examples.

[ chemical formula 19]

[ chemical formula 20]

< barbituric acid Compounds >

As barbituric acid or a derivative thereof, a compound represented by the following general formula (1) can be preferably used.

[ chemical formula 21]

General formula (1)

(wherein R is ¹ 、R ³ R is R ⁵ Each independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aromatic group having 6 to 20 carbon atoms. )

The alkyl group having 1 to 20 carbon atoms is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, still more preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group or an ethyl group.

Cycloalkyl having 3 to 20 carbon atoms is preferably cycloalkyl having 3 to 10 carbon atoms, more preferably cycloalkyl having 4 to 8 carbon atoms. Specific examples of cycloalkyl groups include: cyclopropyl, cyclopentyl, cyclohexyl, and the like, with cyclohexyl being particularly preferred.

Alkenyl groups having 2 to 20 carbon atoms are preferably alkenyl groups having 2 to 10 carbon atoms, and more preferably alkenyl groups having 2 to 5 carbon atoms.

The aromatic group having 6 to 20 carbon atoms may be an aromatic hydrocarbon group, or an aromatic heterocyclic group, and is preferably an aromatic hydrocarbon group. The aromatic hydrocarbon group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group.

R ¹ 、R ³ And R is ⁵ May have a substituent. Examples of the substituent include, but are not limited to, alkyl groups (preferably having 1 to 10 carbon atoms such as methyl, ethyl, isopropyl, t-butyl, pentyl, heptyl, 1-ethylpentyl, benzyl, 2-ethoxyethyl, 1-carboxymethyl and the like), alkenyl groups (preferably having 2 to 20 carbon atoms such as vinyl, allyl, oleyl and the like), alkynyl groups (preferably having 2 to 20 carbon atoms such as ethynyl, butadienyl, phenylethynyl and the like), cycloalkyl groups (preferably having 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl and the like), aryl groups (preferably having 6 to 26 carbon atoms such as phenyl, 1-naphthyl, 4-methoxyphenyl, 2-chlorophenyl, 3-methylphenyl and the like), heterocyclic groups (preferably having 0 to 20 carbon atoms) and ring-forming hetero atoms such as oxygen, nitrogen and sulfur atoms, and may be 5-membered rings or sulfur atoms The 6-membered ring is condensed with a benzene ring or a heterocyclic ring, and the ring may be a saturated ring, an unsaturated ring, an aromatic ring such as a 2-pyridyl group, 4-pyridyl group, 2-imidazolyl group, 2-benzimidazolyl group, 2-thiazolyl group, 2-oxazolyl group or the like), an alkoxy group (preferably having 1 to 20 carbon atoms such as methoxy group, ethoxy group, isopropoxy group, benzyloxy group or the like), an aryloxy group (preferably having 6 to 26 carbon atoms such as phenoxy group, 1-naphthyloxy group, 3-methylphenoxy group, 4-methoxyphenoxy group or the like), an alkylthio group (preferably having 1 to 20 carbon atoms such as methylthio group, ethylthio group, isopropylthio group, benzylthio group or the like), an arylthio group (preferably having 6 to 26 carbon atoms, such as phenylthio, 1-naphthylthio, 3-methylphenylthio, 4-methoxyphenylthio and the like), acyl groups (including alkylcarbonyl groups, alkenylcarbonyl groups, arylcarbonyl groups, heterocyclic carbonyl groups, preferably having not more than 20 carbon atoms, such as acetyl groups, pivaloyl groups, acryl groups, m-chloroacyl groups, benzoyl groups, nicotinyl groups and the like), aroylalkyl groups, alkoxycarbonyl groups (preferably having 2 to 20 carbon atoms, such as ethoxycarbonyl groups, 2-ethylhexyloxycarbonyl groups and the like), aryloxycarbonyl groups (preferably having 7 to 20 carbon atoms, such as phenoxycarbonyl groups, naphthyloxycarbonyl groups and the like), amino groups (including amino groups, alkylamino groups, arylamino groups, heterocyclic amino groups, preferably having 0 to 20 carbon atoms, such as amino groups, N-dimethylamino groups, N-diethylamino groups, N-ethylamino groups, anilino groups, 1-pyrrolidinyl groups, amino groups, and the like, piperidinyl, morpholinyl and the like), sulfonamide (preferably having 0 to 20 carbon atoms, such as N, N-dimethyl sulfonamide, N-phenylsulfonamide and the like), sulfamoyl (preferably having 0 to 20 carbon atoms, such as N, N-dimethyl sulfonamide, N-phenylsulfonamide and the like), acyloxy (preferably having 1 to 20 carbon atoms, such as acetoxy, benzoyloxy and the like), carbamoyl (preferably having 1 to 20 carbon atoms, such as N, N-dimethyl carbamoyl, N-phenylcarbamoyl and the like), acylamino (preferably having 1 to 20 carbon atoms, such as acetylamino, acryloylamino, benzoylamino, nicotinamide and the like), cyano, hydroxyl, mercapto or halogen atom (such as fluorine atom, chlorine atom, bromine atom, iodine atom and the like). R is R ¹ 、R ³ R is R ⁵ The substituent which may be present may further have the substituent.

R ¹ 、R ³ R is R ⁵ Of the substituents which each group of (a) may have, alkyl, aryl, alkoxy, acyl are preferable.

< hansen solubility parameter (HSP value)

The Hansen solubility parameter (HSP value) of the non-organic acid of the present invention is preferably δP (polar force) of 5 to 9MPa ^0.5 Within a range of (2). By making δP 5MPa ^0.5 As described above, the non-organic acid sufficiently performs charge repulsion with the multi-iodine. By making δP 9MPa ^0.5 Hereinafter, the resin has affinity to the resin, and bleeding is suppressed. Further, by setting the repulsive force to a proper value, the orientation of the multi-iodine in the polarizer layer can be maintained.

Further, the ratio of δd (dispersion force) to δp (polar force) of HSP value of the non-organic acid preferably satisfies the following formula.

2< delta D (dispersion force)/delta P (polar force) <4

When the amount is within the above range, the non-organic acid has a proper polarity and is dispersed, so that the movement of the polyiodine can be more effectively suppressed.

The SP value and the HSP value are described below.

As an index for evaluating physical properties of a substance, particularly, dissolution behavior of a solvent, an SP value (solubility parameter; δ) of Hildebrand (Hildebrand) has been conventionally used. The "SP value" refers to a physical property value inherent to a substance expressed by the square root of the aggregation energy density of the substance.

The SP value is expressed by using hansen solubility parameters (HSP values) which are parameters that are expressed by taking into consideration the polarity of a substance, i.e., 3 components divided by hansen into a dispersion force term (δd), a polarity term (δp), and a hydrogen bond term (δh).

SP value= (δd) ² +δP ² +δH ² ) ^0.5

Hansen solubility parameters (HSP values) are based on the idea that "2 substances with similar interactions between molecules are easily dissolved in each other" and consist of the following 3 parameters, which can be regarded as coordinates in three-dimensional space (also referred to as "hansen space"). The closer the distance between the coordinates of the 2 species is, the higher the affinity for each other, and the easier the dissolution is considered.

δD: energy based on intermolecular force of dispersion

δp: energy based on intermolecular dipole interactions

δH: energy based on intermolecular hydrogen bonding

The method for calculating δd, δp, and δh in the hansen solubility parameter is not particularly limited, and may be calculated by inputting the chemical structure into software, or may be calculated experimentally, and preferably, may be calculated by inputting the chemical structure into software.

The HSP values may be obtained using commercially available software, namely, the registered values or the estimated values in HSPIP 5th Edition 5.0.10.1. The software is available from https:// www.hansen-solubility. Furthermore, an estimation method of HSP based on such software is based on, for example, document "Hansen Solubility Parameters" by c.m. hansen et al: a User's Handbook, second Edition "(CRC Press, 2007).

The iodine transfer inhibitor of the present invention preferably further contains sulfate ions, and the content of sulfate ions is in the range of 1 to 100 mass ppm relative to the total mass of the solid content of the resin film for a polarizing plate. By including sulfate ions in the above range, the polarity of the non-organic acid is stabilized in the resin film for a polarizing plate, and charge repulsion is sufficiently performed with multi-iodine.

As a method for measuring the sulfate ion content relative to the total solid content of the resin film for a polarizing plate, a capillary electrophoresis device was used, and the sulfate ion content was compared with a standard sample containing each of the sulfate ions, and the amount was determined by comparing the electrophoresis time (retention time in HPLC).

[1.3 other additives ]

The resin film for a polarizing plate of the present invention may further contain other components than those described above as required. Examples of other ingredients include: antioxidants, rubber particles, matting agents (fine particles) described later, plasticizers, ultraviolet absorbers, and the like. Among them, from the viewpoint of contributing to the improvement of the storage stability of the film over time and imparting toughness (flexibility) to the film, it is preferable to include an antioxidant.

< antioxidant >)

As the antioxidant, a known antioxidant can be used. Particularly, the use of lactones, sulfur compounds, phenols, double bonds, hindered amines, and phosphorus compounds is preferred.

Examples of the lactone compound include "IrgafosXP40 and IrgafosXP60 (trade names)" commercially available from BASF Japan Co., ltd.

Examples of the sulfur compound include "Sumizer (registered trademark) TPL-R" and "Sumizer (registered trademark) TP-D" commercially available from Sumizer chemical Co., ltd. "

Examples of the phenol compound include compounds having a structure of 2, 6-dialkylphenol, and examples thereof include "Irganox (registered trademark) 1076" commercially available from BASF Japan, inc "," Irganox (registered trademark) 1010, "ADK STAB (registered trademark) AO-50" commercially available from ADEKA, inc.

Examples of the double bond compound include "Sumilizer (registered trademark) GM" and "Sumilizer (registered trademark) GS" commercially available from Sumilizer chemical corporation. The content of the double bond compound is in the range of 0.05 to 20 mass%, preferably 0.1 to 1 mass%, relative to the total mass of the thermoplastic resin.

Examples of the hindered amine compound include "Tinuvin (registered trademark) 144" and "Tinuvin (registered trademark) 770" which are commercially available from BASF Japan, and "ADK STAB (registered trademark) LA-52 which is commercially available from ADEKA, inc. "

Examples of the phosphorus compound include "Sumilizer (registered trademark) GP" commercially available from Sumitomo chemical Co., ltd., "ADK STAB (registered trademark) PEP-24G" commercially available from ADEKA, inc., "" ADK STAB (registered trademark) PEP-36 "and" ADK STAB (registered trademark) 3010, "IRGAFOS P-EPQ" commercially available from BASF Japan Co., ltd., and "GSY-P101" commercially available from Saka chemical industry Co., ltd. "

Further, as the acid extender, a compound having an epoxy group described in U.S. Pat. nos. 4,137,201 may be contained.

The content of these antioxidants and the like other than the double bond compound is preferably in the range of 0.0001 to 0.01 mass%, more preferably in the range of 0.002 to 0.01 mass%, relative to the total mass of the thermoplastic resin.

These antioxidants may be used singly or in combination of two or more. For example, a combination of lactones, phosphorus compounds, phenols and double bond compounds is preferable.

< rubber particle >)

The rubber particles are particles containing a rubbery polymer. The rubbery polymer is a soft crosslinked polymer having a glass transition temperature of 20 ℃ or lower. Examples of such crosslinked polymers include: butadiene-based crosslinked polymers, (meth) acrylic crosslinked polymers, and organosiloxane-based crosslinked polymers. Among them, from the viewpoint of a small refractive index difference from the (meth) acrylic resin and less damage to the transparency of the resin film for a polarizing plate, the (meth) acrylic crosslinked polymer is preferable, and the acrylic crosslinked polymer (acrylic rubbery polymer) is more preferable.

That is, the rubber particles are preferably particles containing the acrylic rubbery polymer (a).

Regarding the acrylic rubbery polymer (a):

the acrylic rubbery polymer (a) is a crosslinked polymer containing a structural unit derived from an acrylic acid ester as a main component. The inclusion as the main component means that the content of the structural unit derived from the acrylic acid ester is within a range described later. The acrylic rubbery polymer (a) is preferably a crosslinked polymer containing structural units derived from an acrylic acid ester, structural units derived from other monomers copolymerizable therewith, and structural units derived from a polyfunctional monomer having 2 or more radical polymerizable groups (non-conjugated reactive double bonds) in 1 molecule.

The acrylic acid ester is preferably an alkyl acrylate having 1 to 12 carbon atoms, such as methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, sec-butyl acrylate, isobutyl acrylate, benzyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, and n-octyl acrylate. The acrylic acid ester may be used alone or in combination of two or more.

The content of the structural unit derived from the acrylic acid ester is preferably in the range of 40 to 80 mass%, more preferably in the range of 50 to 80 mass%, relative to the total structural units constituting the acrylic rubber-like polymer (a 1). When the content of the acrylic acid ester is within the above range, sufficient toughness can be easily imparted to the film.

The other copolymerizable monomer is a monomer other than the polyfunctional monomer among the monomers copolymerizable with the acrylic acid ester. That is, the copolymerizable monomer does not have two or more radical polymerizable groups. Examples of copolymerizable monomers include: methacrylate esters such as methyl methacrylate; styrenes such as styrene and methylstyrene; (meth) acrylonitriles; (meth) acrylamides; (meth) acrylic acid. Among them, the other copolymerizable monomer preferably contains a styrene. The other copolymerizable monomer may be used alone or in combination of two or more.

The content of the structural unit derived from the other copolymerizable monomer is preferably in the range of 5 to 55 mass%, more preferably in the range of 10 to 45 mass%, relative to the total structural units constituting the acrylic rubbery polymer (a).

Examples of multifunctional monomers include: allyl (meth) acrylate, triallyl cyanurate, triallyl isocyanurate, diallyl phthalate, diallyl malate, divinyl adipate, divinylbenzene, ethylene glycol di (meth) acrylate, diethylene glycol (meth) acrylate, triethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, dipropylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate.

The content of the structural unit derived from the polyfunctional monomer is preferably in the range of 0.05 to 10 mass%, more preferably in the range of 0.1 to 5 mass%, relative to the total structural units constituting the acrylic rubbery polymer (a). When the content of the polyfunctional monomer is 0.05 mass% or more, the crosslinking degree of the obtained acrylic rubbery polymer (a) is easily increased, and the hardness and rigidity of the obtained film are not easily impaired. Further, when the content is 10 mass% or less, the toughness of the film is not easily impaired.

The monomer composition constituting the acrylic rubbery polymer (a) can be measured, for example, by using the peak area ratio detected by pyrolysis GC-MS.

The glass transition temperature (Tg) of the rubbery polymer is preferably 0℃or lower, more preferably-10℃or lower. When the glass transition temperature (Tg) of the rubbery polymer is 0 ℃ or lower, it is easy to impart moderate toughness to the film. The glass transition temperature (Tg) of the rubbery polymer was measured by the same method as described above.

The glass transition temperature (Tg) of the rubbery polymer can be adjusted by the composition of the rubbery polymer. For example, in order to lower the glass transition temperature (Tg) of the acrylic rubber-like polymer (a), it is preferable to increase the mass ratio (for example, 3 or more, preferably 4 to 10) of the acrylic ester having 4 or more carbon atoms in the alkyl group to the copolymerizable other monomer in the acrylic rubber-like polymer (a).

The particles containing the acrylic rubbery polymer (a) may be particles made of the acrylic rubbery polymer (a), or particles having a hard layer made of a hard crosslinked polymer (c) having a glass transition temperature of 20 ℃ or higher and a soft layer made of the acrylic rubbery polymer (a) disposed around the hard layer (also referred to as "elastomer"), or particles containing an acrylic graft copolymer obtained by polymerizing a mixture of monomers such as methacrylate in the presence of the acrylic rubbery polymer (a) for at least 1 stage. The particles comprising the acrylic graft copolymer may be core-shell type particles having a core portion comprising the acrylic rubbery polymer (a) and a shell portion covering the same.

Regarding the core-shell rubber particles containing the acrylic rubbery polymer:

(core)

The core portion includes an acrylic rubbery polymer (a) and, if necessary, a hard crosslinked polymer (c). That is, the core may have a soft layer formed of an acrylic rubber-like polymer and a hard layer formed of a hard crosslinked polymer (c) disposed inside thereof.

The crosslinked polymer (c) may be a crosslinked polymer containing methacrylate as a main component. That is, the crosslinked polymer (c) is preferably a crosslinked polymer containing a structural unit derived from an alkyl methacrylate, a structural unit derived from another monomer copolymerizable therewith, and a structural unit derived from a polyfunctional monomer.

The alkyl methacrylate may be the above-mentioned alkyl methacrylate, the other copolymerizable monomer may be the above-mentioned styrene, acrylic acid ester or the like, and the polyfunctional monomer may be the same monomer as the above-mentioned polyfunctional monomer.

The content of the structural unit derived from the alkyl methacrylate is preferably in the range of 40 to 100 mass% with respect to the total structural units constituting the crosslinked polymer (c). The content of the structural unit derived from the other copolymerizable monomer is preferably in the range of 60 to 0 mass% relative to the total structural units constituting the other crosslinked polymer (c). The content of the structural unit derived from the polyfunctional monomer is preferably in the range of 0.01 to 10 mass% relative to the total structural units constituting the other crosslinked polymer.

(Shell portion)

The shell portion contains a methacrylic polymer (b) (other polymer) graft-bonded to the acrylic rubbery polymer (a), the methacrylic polymer (b) containing a structural unit derived from methacrylate as a main component. The inclusion as the main component means that the content of the structural unit derived from the methacrylate is within a range described later.

The methacrylate ester constituting the methacrylic polymer (b) is preferably an alkyl methacrylate having 1 to 12 carbon atoms in the alkyl group such as methyl methacrylate. The methacrylate may be used alone or in combination of two or more.

The content of the methacrylate ester is preferably 50 mass% or more with respect to the total structural units constituting the methacrylic polymer (b). By setting the content of the methacrylic acid ester to 50 mass% or more, compatibility with a methacrylic resin containing a structural unit derived from methyl methacrylate as a main component is easily obtained. From the above viewpoint, the content of the methacrylic acid ester is more preferably 70 mass% or more with respect to the entire constituent units constituting the methacrylic acid-based polymer (b).

The methacrylic polymer (b) may further contain structural units derived from other monomers capable of copolymerizing with methacrylate esters. Examples of other monomers that can be copolymerized include: acrylic esters such as methyl acrylate, ethyl acrylate, and n-butyl acrylate; benzyl (meth) acrylate, dicyclopentanyl (meth) acrylate, phenoxyethyl (meth) acrylate, and the like, a (meth) acrylic monomer having an alicyclic, heterocyclic, or aromatic ring (a (meth) acrylic monomer containing a ring).

The content of the structural unit derived from the copolymerizable monomer is preferably 50 mass% or less, more preferably 30 mass% or less, with respect to the total structural units constituting the methacrylic polymer (b).

In this embodiment, since the resin film for a polarizing plate is not stretched, the shape of the rubber particles is preferably approximately spherical. That is, the aspect ratio of the rubber particles when the cross section or the surface of the film is observed is preferably about 1 to 2.

The average particle diameter of the rubber particles is preferably in the range of 100 to 400 nm. When the average particle diameter of the rubber particles is 100nm or more, sufficient toughness and stress relaxation properties can be easily imparted to the film, and when the average particle diameter is 400nm or less, the transparency of the film is not easily impaired. From the above viewpoint, the average particle diameter of the rubber particles is more preferably in the range of 150 to 300 nm.

The average particle diameter of the rubber particles can be calculated by the following method.

The average particle diameter of the rubber particles can be measured as an average value of equivalent circle diameters of 100 particles obtained by SEM imaging or TEM imaging of the surface or slice of the resin film for the polarizing plate. The equivalent circle diameter is obtained by converting the projected area of the particles obtained by photographing into the diameter of a circle having the same area. At this time, rubber particles observed by SEM observation and/or TEM observation at a magnification of 5000 times were used for calculation of the average particle diameter.

The content of the rubber particles is not particularly limited, but is preferably in the range of 5 to 40 mass%, more preferably in the range of 7 to 30 mass%, based on the total mass of the film.

[1.4 physical Properties ]

< phase differences Ro and Rt >)

The resin film for a polarizing plate of the present invention may be provided with a function as an optical film such as a retardation film, in addition to a function as a protective layer.

In this film, for example, from the viewpoint of use as a retardation film for the IPS mode, the retardation Ro in the in-plane direction measured in an environment where the measurement wavelength is 590nm and 23 ℃ and 55% rh is preferably in the range of 0 to 10nm, more preferably in the range of 0 to 5 nm. The retardation Rt in the thickness direction of the film is preferably in the range of-40 to 40nm, more preferably in the range of-25 to 25 nm.

Ro and Rt are defined by the following formulas, respectively.

Formula (a): ro= (n) _x -n _y )×d

Formula (b): rt= ((n) _x +n _y )/2-n _z )×d

(in the formula (I),

n _x the refractive index in the in-plane slow axis direction (direction of maximum refractive index) of the resin film for a polarizing plate,

n _y the refractive index in the direction perpendicular to the in-plane slow axis of the resin film for a polarizing plate,

n _z the refractive index in the thickness direction of the resin film for a polarizing plate is shown,

d represents the film thickness (nm) of the resin film for a polarizing plate. )

The in-plane slow axis of the film was confirmed by an automatic birefringence meter AXOSICAN (Axo Scan Mueller Matrix Polarimeter: manufactured by AXOMETRICS Co.).

Ro and Rt can be determined by the following method.

1) The film was conditioned at 23℃under 55% RH for 24 hours. The average refractive index of the film was measured by an Abbe refractometer, and the film thickness d was measured by a commercially available micrometer.

2) An automatic birefringence meter AXOSCAN (Axo Scan Mueller Matrix Polarimeter: AXOMETRICS Co.) and the retardation Ro and Rt of the film after humidity conditioning was measured at a measurement wavelength of 590nm at 23℃under 55% RH.

The retardation Ro and Rt of the film can be adjusted by, for example, the kind of thermoplastic resin, stretching conditions, and drying conditions. For example, rt can be reduced by increasing the drying temperature.

2 method for producing resin film for polarizing plate of the present invention

The form of the resin film for a polarizing plate of the present invention is not particularly limited, and is preferably, for example, a belt-like form. That is, the resin film for a polarizing plate of the present invention is preferably wound in a roll shape in a direction perpendicular to the width direction thereof to form a roll.

[ method of production ]

The method for producing a resin film for a polarizing plate of the present invention comprises: 1) a step of obtaining a resin film solution for a polarizing plate, 2) a step of applying the obtained resin film solution for a polarizing plate to a surface of a support, and 3) a step of removing a solvent from the applied resin film solution for a polarizing plate to form a resin film for a polarizing plate.

1) Step of obtaining solution for resin film for polarizing plate

A solution for a resin film for a polarizing plate (also referred to as a "film solution" or a "dope") containing a thermoplastic resin, an iodine movement inhibitor and a solvent is prepared. The solution for a membrane may suitably contain sulfate ions.

The film solutions were prepared as follows: the iodine migration inhibitor and the solvent of the powder or the liquid (dispersion in the case of metal oxide particles) are added, sulfuric acid is further added and stirred as the case may be, and then the resin is added and stirred.

When the metal oxide particles are used as the iodine migration inhibitor, the metal oxide particles are dispersed in a solvent used in a film solution described below in a particulate form to obtain a dispersion. The dispersion of the metal oxide particles can be performed by using mechanical energy, and as described above, examples thereof include a low-speed shear type dispersion machine, a high-speed shear type dispersion machine, a friction type dispersion machine, an ultrasonic dispersion machine such as a high-pressure jet type dispersion machine, an ultrasonic homogenizer, a high-pressure impact type dispersion machine UL timzone, and the like.

The solvent used in the solution for a resin film for a polarizing plate is not particularly limited as long as the solvent can satisfactorily disperse or dissolve the resin. For example, examples of the organic solvent used in the present invention include: alcohols (methanol, ethanol, diols, triols, tetrafluoropropanol, etc.), glycols, cellosolves, ketones (acetone, methyl ethyl ketone, etc.), carboxylic acids (formic acid, acetic acid, etc.), carbonates (ethylene carbonate, propylene carbonate, etc.), esters (ethyl acetate, propyl acetate, etc.), ethers (isopropyl ether, THF, etc.), amides (dimethyl sulfoxide, etc.), hydrocarbons (heptane, etc.), nitriles (acetonitrile, etc.), aromatics (cyclohexylbenzene, toluene, xylene, chlorobenzene, etc.), haloalkyl (dichloromethane (also referred to as "dichloromethyl") etc.), amines (1, 4-diazabicyclo [2.2.2] octane, diazabicycloundecene, etc.), lactones, etc.

Among them, the solvent of the film solution preferably has a boiling point of 100 ℃ or less at atmospheric pressure, and further preferably is a chlorine-based solvent. More specifically, dichloromethane is more preferable. The solvent is methylene chloride, which is easy to handle because of its high solubility, and the drying speed is high because of its high volatility, so that it is easy to adjust the film quality of the coating film.

In addition, a hydrophilic solvent may be added to the solvent of the film solution. Examples of the hydrophilic solvent include ketones and alcohols, and alcohols are preferable. More preferably isopropanol, ethanol, methanol, etc., and still more preferably methanol. The amount of the solvent to be added is preferably in the range of 1 to 20 mass%, more preferably in the range of 3 to 10 mass%, based on the total mass of the solvent in the film solution.

From the viewpoint of easy adjustment of the viscosity to a range described later, the concentration of the resin in the film solution is preferably in the range of 1.0 to 20 mass% relative to the total mass of the film solution, for example. Further, from the viewpoint of reducing the shrinkage amount at the time of drying of the coating film, the concentration of the resin in the film solution is preferably moderately high, more preferably in the range of more than 5% by mass and 20% by mass or less, and still more preferably in the range of more than 5% by mass and 15% by mass or less.

By adjusting the concentration of the resin, the time until the formation of the coating film is shortened, and the drying time and the surface state of the film can be controlled. In addition, by properly using the mixed solvent, the concentration of the resin can be increased.

The viscosity of the film solution is not particularly limited as long as it can form a resin film for a polarizing plate having a desired film thickness, and is preferably in the range of 5 to 5000mpa·s, for example. When the viscosity of the solution for a film is 5mpa·s or more, a film having a proper film thickness can be easily formed, and when the viscosity of the solution is 5000mpa·s or less, occurrence of film thickness unevenness due to an increase in the viscosity of the solution can be suppressed. From the above viewpoint, the viscosity of the film solution is more preferably in the range of 100 to 1000mpa·s. The viscosity of the film solutions can be measured at 25℃using an E-type viscometer.

2) A step of applying a solution for a resin film for a polarizing plate

Next, the obtained solution for a film is applied to the surface of the support. Specifically, the obtained solution for a film is applied to the surface of a support.

< support body >

The support is supported by a resin film for the polarizing plate, and a resin film can be generally used. The thickness of the support is preferably 50 μm or less. The thickness of the support is preferably in the range of 15 to 45 μm, more preferably in the range of 20 to 40 μm, from the viewpoint of being a film and requiring a certain degree of strength (toughness, rigidity) as a support.

Examples of the resin used for the resin film used as the support include: among them, polyester resins are preferably used as resins excellent in storage stability under a high humidity environment.

Further, as examples of the resin film, there may be mentioned: polyester resins (e.g., polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), etc.), and the like. Among them, from the viewpoint of ease of handling, a polyester resin film containing polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) is preferable.

The resin film may be a film subjected to heat treatment (heat relaxation), or may be a film subjected to stretching treatment.

The heat treatment is a treatment for reducing residual stress (for example, residual stress accompanying stretching) of the resin film. The temperature is not particularly limited, and when the glass transition temperature of the resin constituting the resin film is Tg, it is preferably (tg+60) to (tg+180) ℃.

The stretching treatment is performed to increase the residual stress of the resin film, and is preferably performed in the biaxial direction of the resin film, for example. The stretching treatment may be performed under any conditions, and may be performed, for example, in a range of about 120 to 900% of stretching magnification. Whether the resin film is stretched or not can be confirmed by, for example, whether or not there is an in-plane slow axis (axis extending in the direction in which the refractive index reaches the maximum). The stretching treatment may be performed before the functional layers are stacked, or may be performed after the functional layers are stacked, and stretching is preferably performed before the functional layers are stacked.

As the polyester resin film (also simply referred to as a polyester film), commercially available ones can be used, and for example, polyethylene terephthalate film TN100 (manufactured by eastern spinning corporation), MELINEX (registered trademark) ST504 (manufactured by TEIJIN DUPONT FILMS corporation) and the like can be preferably used.

The support may further have a release layer on the surface of the resin film. When the resin film for a polarizing plate of the present invention is produced by having a release layer, the support is easily peeled off.

The release layer may contain a known release agent, and is not particularly limited. Examples of the release agent contained in the release layer include silicone release agents and non-silicone release agents.

Examples of the silicone-based release agent include known silicone-based resins. Examples of non-silicone based release agents include: a long-chain alkyl side chain (pendant) polymer obtained by reacting a long-chain alkyl isocyanate with polyvinyl alcohol or an ethylene-vinyl alcohol copolymer, an olefin resin (for example, a copolymer of polyethylene, cyclic polyolefin, polymethylpentene), a polyarylate resin (for example, a polycondensate of an aromatic dicarboxylic acid component and a dihydric phenol component), a fluororesin (for example, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), PFA (a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene), FEP (a copolymer of tetrafluoroethylene and hexafluoropropylene), ETFE (a copolymer of tetrafluoroethylene and ethylene)), and the like.

The thickness of the release layer is not particularly limited as long as it can exhibit a desired peelability, and is preferably in the range of 0.1 to 1.0 μm, for example.

In the support, as an additive, a plasticizer may be contained. The plasticizer is not particularly limited, and examples thereof include polyol ester plasticizers, phthalate plasticizers, citric acid plasticizers, fatty acid ester plasticizers, phosphate plasticizers, polycarboxylic acid ester plasticizers, and polyester plasticizers.

In addition, the support may contain an ultraviolet absorber. Examples of the ultraviolet absorber used include: benzotriazoles, 2-hydroxybenzophenones, or phenyl salicylates, and the like. Specifically, there may be mentioned: triazoles such as 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- [ 2-hydroxy-3, 5-bis (. Alpha.,. Alpha. -dimethylbenzyl) phenyl ] -2H-benzotriazole, 2- (3, 5-di-t-butyl-2-hydroxyphenyl) benzotriazole, benzophenones such as 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 2,2' -dihydroxy-4-methoxybenzophenone, and the like.

In order to improve the transport property, the support used in the present invention preferably further contains fine particles.

As the fine particles, as examples of the inorganic compound, there are given: silica, titania, alumina, zirconia, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, and calcium phosphate.

Further, as the fine particles, fine particles of an organic compound can be preferably used. As examples of the organic compound, there may be mentioned: polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropylene, polymethyl acrylate, polyethylene carbonate, acrylic styrene resins, polysiloxane resins, polycarbonate resins, benzoguanamine resins, melamine resins, polyolefin powders, polyester resins, polyamide resins, polyimide resins, or pulverized fractions of organic polymer compounds such as polyvinyl fluoride resins and starches, polymer compounds synthesized by suspension polymerization, and the like.

From the viewpoint of reducing turbidity, the fine particles preferably contain silicon, and particularly preferably are silica. As the fine particles of silica, commercially available ones can be used, and examples thereof include AEROSIL (registered trademark) R972, R972V, R974, R812, 200V, 300, R202, OX50, TT600 (the above is manufactured by japan AEROSIL corporation) and the like.

As a method for producing the support used in the present invention, a usual production method such as a blow-up method, a T-die method, a rolling method, a cutting method, a casting method, an emulsion method, a hot pressing method, etc. can be used, and from the viewpoints of suppressing coloration, suppressing foreign matter defects, suppressing optical defects such as a die line, etc., the film production method is preferably a solution casting method or a melt casting method. In addition, in the case of the solution casting method, the temperature in the processing step is relatively low, and thus various additives can be used to further impart functions.

In the case of film formation by the solution casting method, the method for producing the support preferably includes: a step of preparing a dope by dissolving and dispersing the thermoplastic resin and the additive such as the fine particles in a solvent (dissolution step; dope preparation step); a step of casting the dope on an endless metal support (casting step); a step (solvent evaporation step) of drying the cast dope as a web; a step of peeling from the metal support (peeling step); drying, stretching, and maintaining the width (stretching, maintaining the width, and drying step); and a step (winding step) of winding the completed film into a roll.

The resin film for a polarizing plate of the present invention is preferably formed by the following method using the support manufactured as described above.

The method of applying the solution for the resin film for a polarizing plate is not particularly limited, and may be, for example, a known method such as a back roll coating method, a gravure coating method, a spin coating method, a bar coating method, or a roll coating method. Among them, the back coating method is preferable in terms of forming a thin and uniform film thickness of the coating film.

3) Step of Forming resin film for polarizing plate

Next, the solvent is removed from the solution for the resin film for a polarizing plate applied to the support, thereby forming a resin film for a polarizing plate.

Specifically, the solution for film applied to the support is dried. Drying may be performed by, for example, blowing or heating. Among them, drying by blowing is preferable from the viewpoint of easily suppressing curling of the film, and a difference in wind speed between the initial stage and the latter half of drying is preferably given from the viewpoint of enabling control of the film thickness variation described below. Specifically, when the initial wind speed is high, the film thickness deviation tends to be large, and when the initial wind speed is low, the film thickness deviation tends to be small.

Therefore, by adjusting the drying conditions (for example, the drying temperature, the drying air volume, the drying time, and the like), the density of the resin film for a polarizing plate can be controlled, and the thickness of the film can be adjusted within a range satisfying the following formula.

Average value (B) -average film thickness value (A) |/average film thickness value (A) ×100<20 (%)

Here, the average film thickness value (a) is an average value of film thickness values of 10 points randomly extracted from the film.

When the value represented by the above formula exceeds 5%, the surface has appropriate irregularities, and the adhesion to the upper layer is improved, and when the value is less than 20%, the irregularities on the surface are not excessively large, and the coating property and smoothness of the upper layer are not affected.

As a film thickness measuring system, for example, F20-UV (manufactured by FILMETRICS Co.) can be mentioned.

Further, the thickness deviation ρ of the resin film for a polarizing plate is preferably adjusted to be in the range of 0.5±0.2 μm. In addition, from the viewpoint of improving adhesion to the upper layer, it is preferable to adjust the film quality in a direction in which the film quality becomes thin. Specifically, the drying rate is preferably increased, preferably in the range of 0.0015 to 0.05 kg/hr.m ² More preferably in the range of 0.002 to 0.05 kg/hr.m ² Within a range of (2).

The drying rate is expressed as the mass of solvent evaporated per unit time and per unit area. The drying speed can generally be adjusted by the drying temperature. The drying temperature also depends on the kind of the solvent used, and is preferably, for example, 50 to 200 ℃ (in the range of (Tb-50) to (Tb+50) DEG C with respect to the boiling point Tb of the solvent used). The temperature control may be performed in multiple stages. After drying to a certain extent, the drying rate and the film quality can be controlled by drying at a higher temperature.

As described above, the resin film for a polarizing plate of the present invention is preferably in a band shape. Therefore, the method for producing a laminated film according to the present embodiment preferably further includes 4) a step of winding the strip-shaped laminated film into a roll to form a roll.

4) Winding a resin film for a polarizing plate to obtain a roll

The obtained resin film for a band-shaped polarizing plate is wound in a roll shape in a direction perpendicular to the width direction thereof, and a roll body is produced.

The length of the resin film for a band-shaped polarizing plate is not particularly limited, and is preferably in the range of 100 to 10000m, for example. The width of the resin film for a band-shaped polarizing plate is preferably 1m or more, and more preferably in the range of 1.1 to 4 m. From the viewpoint of improving the uniformity of the film, it is more preferably in the range of 1.3 to 2.5 m.

[ manufacturing apparatus ]

The method for producing a resin film for a polarizing plate of the present invention can be carried out, for example, by using a production apparatus shown in fig. 1.

Fig. 1 is a schematic view of a manufacturing apparatus B200 for carrying out the method for manufacturing a resin film for a polarizing plate of the present invention. The manufacturing apparatus B200 includes a supply unit B210, an application unit B220, a drying unit B230, a cooling unit B240, and a winding unit B250.Ba to Bd denote conveying rollers that convey the support B110.

The supply unit B210 includes a paying-out device (not shown) for paying out the roll B201 of the band-shaped support body B110 wound around the winding core.

The coating unit B220 is a coating apparatus, and includes: a support roller B221 that holds the support body B110; a coating head B222 that coats the solution for the resin film for the polarizing plate on the support B110 held by the support roller B221; and a decompression chamber B223 provided on the upstream side of the coating head B222.

The flow rate of the solution for the resin film for a polarizing plate discharged from the coating head B222 can be adjusted by a pump not shown. The flow rate of the solution for the resin film for a polarizing plate discharged from the coating head B222 is set to an amount that can stably form a coating layer of a given thickness when continuously coated under the conditions of the coating head B222 adjusted in advance.

The decompression chamber B223 is a mechanism for stabilizing the bead (accumulation of the coating liquid) formed between the solution for the resin film for the polarizing plate from the coating head B222 and the support B110 at the time of coating, and can adjust the decompression degree. The decompression chamber B223 is connected to a decompression blower (not shown), and the inside is decompressed. The decompression chamber B223 is in a state where no air leaks, and the gap between the decompression chamber B and the support roller is also adjusted to be narrow, so that a stable bead of the coating liquid can be formed.

The drying unit B230 is a drying device for drying a coating film applied to the surface of the support B110, and includes a drying chamber B231, an inlet B232 for a drying gas, and an outlet B233. The temperature and the air volume of the drying air are appropriately determined according to the type of the coating film and the type of the support B110. By setting the conditions such as the temperature of the drying air, the air volume, and the drying time in the drying unit B230, the amount of residual solvent in the dried coating film can be adjusted. The residual solvent amount of the dried coating film can be measured by comparing the unit mass of the dried coating film with the unit mass of the coating film after sufficient drying.

(residual solvent amount)

Since the resin film for a polarizing plate of the present invention is obtained by coating a film solution, a solvent derived from the solution may remain. The amount of residual solvent can be controlled by using a solvent, a solution concentration, a wind speed at the time of film drying, a drying temperature, a time, a condition of a drying chamber (external air or internal air circulation), a heating temperature of a back roller at the time of coating, and the like.

As described above, by increasing the drying speed, the film becomes sparse, and the surface state can be controlled.

From the viewpoint of film curl balance, the residual solvent amount S1 of the resin film for polarizing plate is preferably in the range of more than 10ppm and less than 1000 ppm.

Further, from the viewpoint of improving the curl balance of the film, the residual solvent amount of the resin film for a polarizing plate is more preferably in the range of more than 100ppm and less than 800ppm, and still more preferably in the range of 500ppm or more and less than 700 ppm. In addition, by selecting a solvent-coating process in which a solvent remains in the support, adhesion between the support and the resin film for a polarizing plate is improved. The amount of the residual solvent in the support is preferably in the range of 10 to 100 ppm.

The residual solvent amount of the support and the resin film for a polarizing plate can be measured by headspace gas chromatography. In headspace gas chromatography, a sample is sealed in a container and heated, and the gas in the container is rapidly injected into a gas chromatograph in a state where the container is filled with volatile components, and mass analysis is performed, and the volatile components are quantified while the compound is identified. In the headspace method, all peaks of volatile components can be observed by a gas chromatograph, and by using an analysis method using electromagnetic interaction, the volatile substances, monomers, and the like can be quantified at once with high accuracy.

The cooling unit B240 cools the temperature of the support B110 having the coating film dried by the drying unit B230, and adjusts the temperature to an appropriate temperature. The cooling unit B240 includes a cooling chamber B241, a cooling air inlet B242, and a cooling air outlet B243. The temperature and the air volume of the cooling air are appropriately determined according to the type of the coating film and the type of the support B110. Further, even if the cooling unit B240 is not provided, the cooling unit B240 may be omitted when the cooling temperature is set to an appropriate level.

The winding unit B250 is a winding device (not shown) for winding the support B110 on which the resin film for polarizing plates is formed to obtain a roll B251.

3 polarizer

The polarizing plate of the present invention is a polarizing plate having an adhesive layer and a polarizer layer on a resin film, and comprises the resin film for a polarizing plate of the present invention as a resin film. The resin film preferably has a function as a retardation film as the protective layer. The resin film for a polarizing plate of the present invention may be used to protect both sides of the polarizing plate layer, and other conventionally known protective layers may be used. The support used in forming the resin film for a polarizing plate may or may not be peeled off.

Fig. 2 shows an example of a preferable layer structure of the polarizing plate of the present invention, but is not limited thereto.

Fig. 2 is a cross-sectional view of the basic layer structure of the polarizing plate of the present invention.

The polarizing plate 10 of the present invention is basically constituted by bonding the resin film 1 for a polarizing plate of the present invention to the polarizer layer 3 via the adhesive layer 2. The protective layer 4 is attached to the surface of the polarizer 3 opposite to the surface of the polarizer resin film 1 of the present invention via the adhesive layer 2, if necessary. The protective layer is not particularly limited, and the resin film for a polarizing plate of the present invention may be used, or a retardation film described later may be used.

The polarizer of the present invention can suppress the movement of iodine contained in the polarizer layer by providing the resin film for a polarizer of the present invention. Therefore, the decrease in the adhesion between the polarizer layer and the polarizer resin film due to heat generation of the semiconductor substrate can be suppressed, and in the display device including the polarizer of the present invention, the deterioration in contrast can be suppressed.

[3.1 polarizer layer ]

The polarizer layer of the present invention is preferably a polyvinyl alcohol (PVA) iodine-dyed polarizer layer obtained by dyeing a PVA film with iodine. By using this polarizer layer, the effects of the present invention can be expected. "polarizer" means an element that passes light having a polarization plane in a certain direction only. Hereinafter, a preferred structure of the polarizer layer of the present invention is shown as an example, but is not limited thereto.

The thickness of the polarizer layer of the present invention is preferably in the range of 4 to 15. Mu.m. By setting the range to be within the above range, the polarizing plate can be thinned.

[3.1.1PVA iodine dyeing polarizer layer ]

The thickness of the PVA film used for the PVA iodine dyeing polarizing layer before stretching is preferably 5 to 300 μm, particularly preferably 10 to 200 μm, from the viewpoints of film holding stability and stretching uniformity. Further, as described in Japanese patent application laid-open No. 2002-236212, a thin PVA film having a stress of 10N or less generated when stretching is performed 4 to 6 times in water may be used.

The thickness of the PVA film after stretching is preferably in the range of 3 to 30. Mu.m, more preferably in the range of 3 to 20. Mu.m, still more preferably in the range of 3 to 15. Mu.m. By setting the range to the above range, warpage and deformation of the liquid crystal panel due to ambient humidity can be reduced, and display unevenness can be improved.

The PVA film is preferably a polymer material obtained by saponifying polyvinyl acetate, and may contain, for example, a component copolymerizable with vinyl acetate such as an unsaturated carboxylic acid, an unsaturated sulfonic acid, an olefin, or a vinyl ether. Further, modified PVA containing acetoacetyl group, sulfonic acid group, carboxyl group, oxyalkylene group, or the like may also be used.

Further, a PVA film having a 1, 2-glycol bond content of 1.5 mol% or less as described in Japanese patent application laid-open No. 3021494 and a PVA film having a 1-316492 per 100cm as described in Japanese patent application laid-open No. 2001-316492 can be preferably used ² PVA film having 500 or less optical foreign matter of 5 μm or more, PVA film having a hot water cut-off temperature unevenness of 1.5 ℃ or less in TD direction of the film described in JP-A No. 2002-030163, solution comprising 3-6 valent polyol such as glycerin in an amount of 1-100% by mass, and film comprising 15% or more by mass in an amount of 15% or more described in JP-A No. 06-289225 And PVA film formed by film formation of plasticizer solution.

The dyed iodine is preferably I ₃ ^- 、I ₅ ^- An isovalent iodide ion (polyiodide). The high-valence iodide ions can be produced by immersing a PVA film in a liquid obtained by dissolving iodine in an aqueous potassium iodide solution and/or an aqueous boric acid solution, as described in "application of a polarizing plate" Yong Tian Liang, CMC publication, industrial materials, volume 28, no. 7, and p.39 to p.45, to adsorb and orient the PVA film.

The iodine content is preferably in the range of 1 to 5 mass%, more preferably in the range of 2 to 4 mass%, relative to the total mass of the polarizer layer. When the amount is within the above range, a polarizing plate having a desired transmittance can be obtained, and a liquid crystal display device having a high contrast in the front direction can be obtained.

The polarizer layer preferably contains boric acid as a crosslinking agent. By crosslinking with boric acid, the stability of a complex formed from iodine and PVA is improved, and deterioration of polarization properties under high temperature and high humidity conditions can be suppressed.

The boric acid content is preferably in the range of 0.5 to 3.0 mass%, more preferably in the range of 1.0 to 2.8 mass%, and even more preferably in the range of 1.5 to 2.6 mass% relative to the total mass of the polarizer layer in terms of boron.

The dichroic ratio DR of the polarizer layer is preferably 160 or more, more preferably 160 to 220, still more preferably 170 to 210, and particularly preferably 175 to 185. By setting the ratio within the above range, a liquid crystal panel and a liquid crystal display device having a high front contrast ratio can be obtained. Such a liquid crystal panel and a liquid crystal display device are suitable for television applications, for example. The dichroic ratio DR is obtained by the following formula.

The dichroic ratio dr=log (0.919/k 2)/log (0.919/k 1)

Here, k1 is the transmittance in the transmission axis direction of the polarizer layer, k2 is the transmittance in the absorption axis direction of the polarizer layer, and the constant 0.919 is the interface reflectance.

The transmittance (monomer transmittance) Ts of the polarizer layer is preferably 42% or more, more preferably in the range of 42.0 to 44.0%, and still more preferably in the range of 42.5 to 43.0%. By setting the range to be within the above range, a liquid crystal panel or a liquid crystal display device having the polarizing plate of the present invention and having high brightness can be obtained. Such a liquid crystal panel and a liquid crystal display device are suitable for television applications, for example. The transmittance of the polarizing plate can be obtained by the following formula.

Transmittance (%) = { (k1+k2)/2 } ×100

Here, k1 is the transmittance in the transmission axis direction of the polarizer layer, and k2 is the transmittance in the absorption axis direction of the polarizer layer.

The linear expansion coefficient of the polarizer layer in the transmission axis direction is not particularly limited, and is preferably 4.0X10 ^～5 ～5.0×10 ^～5 Within the range of/. Degree.C.

[ method of production ]

The method for producing the PVA iodine-dyed polarizer used in the present invention is not particularly limited, and for example, it is preferable to prepare the PVA by converting the PVA into a film and then introducing iodine. The PVA film can be produced by the methods described in paragraphs 0213 to 0237 of JP-A2007-86748, JP-A3342516, JP-A09-328593, JP-A2001-302817, JP-A2002-144401, and the like.

As a method for producing the PVA iodine-dyed polarizer layer, for example, a method in which a PVA solution preparation step, a casting step, a swelling step, a dyeing step, a film fixing step, a stretching step, and a drying step are sequentially performed is preferable. In addition, an Online (Online) surface inspection process may be provided during or after the trip.

(preparation of PVA solution)

In the PVA solution preparation step, a stock solution obtained by dissolving PVA in water or an organic solvent is preferably prepared. The concentration of PVA in the stock solution is preferably in the range of 5 to 20 mass%. For example, a method of placing the wet cake of PVA in a dissolution tank, adding a plasticizer and water as needed, and stirring while blowing steam from the tank bottom is preferable. The internal resin temperature is preferably heated to 50 to 150℃and the system may be pressurized.

(casting)

The casting step preferably uses a method of casting the PVA solution raw material prepared as described above to form a film. The casting method is not particularly limited, and a film is preferably produced by supplying the heated PVA solution stock solution to a twin screw extruder and casting the PVA solution onto a support from a discharge unit (preferably a die, more preferably a T-slot die) using a gear pump. In addition, there is no particular limitation on the temperature of the PVA solution discharged from the die.

As the support, a casting cylinder is preferable, and there are no particular restrictions on the diameter, width, rotational speed, and surface temperature of the cylinder.

Then, the back surface and the front surface of the obtained roll are preferably dried while alternately passing through a drying roll.

(swelling)

The swelling step is preferably performed using only water, and as described in JP-A-10-153709, the swelling degree of the PVA film may be controlled by swelling the PVA film with an aqueous boric acid solution for the purpose of stabilizing the optical properties and avoiding the occurrence of wrinkles in the PVA film on the production line.

The temperature and time of the swelling step may be arbitrarily determined, and are preferably in the range of 10 to 60℃and 5 to 2000 seconds.

The stretching may be performed slightly at the time of the swelling step, and for example, stretching is preferably performed to about 1.3 times.

(dyeing)

As the dyeing step, a method described in JP 2002-86554A can be used. The dyeing method may be any method such as dipping, or iodine coating or spraying. Further, as described in japanese patent application laid-open No. 2001-296427, a polarizer having a high light transmittance and a high polarization ratio of the polarizer layer is obtained by setting the concentration of iodine, the dyeing bath temperature, and the stretching ratio in the bath to appropriate values and dyeing the bath liquid while stirring the bath liquid in the bath.

In the case of using an expensive iodide ion, in order to obtain a polarizing plate having a high contrast, a liquid in which iodine is dissolved in an aqueous potassium iodide solution is preferably used in the dyeing step. The mass ratio of iodine to potassium iodide in the iodine-potassium iodide aqueous solution can be as described in Japanese patent application laid-open No. 2007-086748.

Further, as described in japanese patent No. 3145747, a boron compound such as boric acid or borax may be added to the dyeing liquid.

(solid film)

The film fixing step preferably includes immersing or coating the solution in a crosslinking agent solution to contain the crosslinking agent. Further, as described in JP-A-11-52130, the film-fixing step may be divided into several times.

As the crosslinking agent, a crosslinking agent described in us reissue patent No. 232897 can be used, and as described in patent No. 3357109, a polyaldehyde can be used, and boric acid is preferably used, in order to improve dimensional stability. When boric acid is used as the crosslinking agent used in the film-fixing step, a metal ion may be added to the aqueous boric acid-potassium iodide solution. As the metal ion, zinc chloride is preferable, and as described in japanese unexamined patent publication No. 2000-35512, zinc halide such as zinc iodide, zinc sulfate, zinc acetate, and other zinc salts may be used instead of zinc chloride.

Alternatively, an aqueous solution of boric acid and potassium iodide to which zinc chloride is added may be prepared, and a PVA film may be impregnated to fix the film, and the method described in japanese patent application laid-open No. 2007-086748 may be used.

Here, as a method for improving durability in a high-temperature environment, a dipping treatment with a known acidic solution may be performed. Examples of the treatment with an acidic solution include the methods described in JP-A-2001-83329, JP-A-6-254958, international publication WO2006/095815, and the like.

(stretching)

The stretching step may be preferably performed by a longitudinal uniaxial stretching method described in U.S. Pat. No. 2454515 or the like, or a tenter method described in Japanese unexamined patent publication No. 2002-86554. The stretch ratio is preferably in the range of 2 to 12 times, more preferably in the range of 3 to 10 times.

The relationship between the stretching ratio, the roll thickness and the thickness of the polarizer layer may be preferably set to (polarizer film thickness after the attachment of the protective film/roll film thickness) × (total stretching ratio) >0.17 described in japanese patent application laid-open No. 2002-040256, or the relationship between the width of the polarizer layer at the time of final bath-out and the width of the polarizer layer at the time of attachment of the protective film may be preferably set to 0.80 or less (width of the polarizer layer at the time of attachment of the protective film/width of the polarizer at the time of final bath-out) or 0.95 or less described in japanese patent application laid-open No. 2002-040247. The protective film herein has the same meaning as the protective layer in the present invention.

(drying)

The drying step may be carried out by a known method described in Japanese unexamined patent publication No. 2002-86554, and the temperature is preferably in the range of 30 to 100℃and the drying time is preferably in the range of 30 seconds to 60 minutes. Further, it is preferable to perform heat treatment for bringing the fading temperature in water to 50℃or higher as described in Japanese patent application laid-open No. 3148513 or to perform curing in temperature and humidity-controlled air as described in Japanese patent application laid-open No. 07-325215 and Japanese patent application laid-open No. 07-325218.

By the above-described steps, the polarizer layer is preferably manufactured so that the thickness thereof is in the range of 4 to 15 μm. The thickness may be controlled by a known method, for example, by setting the slit width and the stretching conditions in the casting step to appropriate values.

[3.2 adhesive layer ]

The polarizing plate of the present invention is obtained by laminating a protective layer on both sides of the obtained polarizer layer with an adhesive layer interposed therebetween. The resin film for a polarizing plate of the present invention may be used to protect both sides of the polarizing plate layer, and other conventionally known protective layers may be used.

The adhesive layer of the present invention is formed of an adhesive. Examples of the adhesive include isocyanate adhesives, polyvinyl alcohol adhesives, gelatin adhesives, vinyl latex, and aqueous polyesters. These adhesives are generally used as adhesives (aqueous adhesives) composed of an aqueous solution, and the solid content concentration of the adhesive in the aqueous solution is preferably in the range of 0.5 to 60 mass%. Among them, polyvinyl alcohol adhesives are preferable, and polyvinyl alcohol adhesives containing an acetoacetyl group are more preferable.

The aqueous binder may comprise a cross-linking agent. As the crosslinking agent, a compound having at least 2 functional groups in 1 molecule which are reactive with components such as a polymer constituting the adhesive is generally used, and examples thereof include: alkylene diamines; isocyanates; epoxy; aldehydes; amino-formaldehyde such as methylol urea and methylol melamine. The content of the crosslinking agent in the adhesive is preferably in the range of 10 to 60 mass% relative to the components such as the polymer constituting the adhesive.

Examples of the adhesive include an active energy ray-curable adhesive such as an ultraviolet-curable adhesive and an electron beam-curable adhesive, in addition to the above. Examples of the active energy ray-curable adhesive include (meth) acrylate adhesives. Examples of the curable component in the (meth) acrylic adhesive include a compound having a (meth) acryloyl group and a compound having a vinyl group. Examples of the compound having a (meth) acryloyl group include alkyl (meth) acrylates such as chain alkyl (meth) acrylate having 1 to 20 carbon atoms, alicyclic alkyl (meth) acrylate, and polycyclic alkyl (meth) acrylate; (meth) acrylate containing a hydroxyl group; glycidyl (meth) acrylate and the like, (meth) acrylate containing an epoxy group. The (meth) acrylate adhesive may comprise: nitrogen-containing monomers such as hydroxyethyl (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-ethoxymethyl (meth) acrylamide, and (meth) acryloylmorpholine. The (meth) acrylic acid ester-based adhesive may contain a polyfunctional monomer such as tripropylene glycol diacrylate, 1, 9-nonanediol diacrylate, tricyclodecane dimethanol diacrylate, cyclic trimethylolpropane methylacrylate (cyclicmomethylpropane formal), dioxane glycol diacrylate, EO-modified diglycerol tetraacrylate, or the like as a crosslinking component. In addition, as the cationic polymerization curable adhesive, a compound having an epoxy group or an oxetanyl group may be used. The compound having an epoxy group is not particularly limited as long as it has at least 2 epoxy groups in the molecule, and various conventionally known curable epoxy compounds can be used.

The adhesive may contain suitable additives as required. Examples of the additives include coupling agents such as silane coupling agents and titanium coupling agents, adhesion promoters such as ethylene oxide, ultraviolet absorbers, deterioration inhibitors, dyes, processing aids, ion capturing agents, antioxidants, tackifiers, fillers, plasticizers, leveling agents, foaming inhibitors, antistatic agents, heat stabilizers, and hydrolysis stabilizers.

The adhesive may be applied on either the protective layer side or the polarizer layer side, or both. After bonding, a drying step is performed to form an adhesive layer composed of a coated and dried layer. After the adhesive drying step, ultraviolet rays and electron beams may be irradiated as necessary.

The method of bonding the protective layer and the polarizer layer is preferably such that the transmission axis of the polarizer layer is substantially parallel to the slow axis of the protective layer.

Substantially parallel means that the principal refractive index n of the protective layer _x Is shifted within 5 DEG in the direction of the transmission axis of the polarizer layer. The offset is more preferably 1 ° or less, and still more preferably 0.5 ° or less. If the shift is within 1 °, the polarization performance of the polarizing plate in crossed nicols is not easily reduced, and light leakage is not easily generated.

The thickness of the adhesive layer of the present invention is not particularly limited, and in the case of using an aqueous adhesive or the like, it is preferably in the range of 30 to 5000nm, more preferably in the range of 100 to 1000 nm. In the case of using an ultraviolet-curable adhesive, an electron beam-curable adhesive, or the like, the range is preferably 0.1 to 100. Mu.m, more preferably 0.5 to 10. Mu.m.

[3.3 protective layer ]

As the protective layer 4 shown in fig. 2, a conventionally known protective layer may be used in addition to the resin film for a polarizing plate of the present invention, and a cellulose acylate film, a polyester film (for example, a polyethylene terephthalate film or the like), a cycloolefin resin film, an acrylic resin film or the like may be used.

Examples of the commercial products of the cellulose acylate film include Konica Minolta Tac KC UX, KC5UX, KC4UX, KC8UC R3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC6UY, KC4UE, KC8UY-HA, KC2UA, KC4UA, KC6UA, KC2UAH, KC4UAH, KC6UAH, and the like manufactured by Konica Minolta Advanced Lay er corporation.

The thickness of the protective layer is not particularly limited, but is preferably in the range of 1 to 100. Mu.m, more preferably in the range of 3 to 40. Mu.m, and still more preferably in the range of 5 to 20. Mu.m.

4 display device

The display device of the present invention can suppress deterioration of contrast by providing the polarizing plate of the present invention.

The display device of the present invention is obtained by bonding the polarizing plate of the present invention to the surface of the display device via an adhesive layer or an adhesive layer, for example. The display device is a device having a display mechanism, and includes a light emitting element or a light emitting device as a light emitting source.

Examples of the display device include a liquid crystal display device, an organic Electroluminescence (EL) display device, an inorganic Electroluminescence (EL) display device, a touch panel display device, an electron emission display device (a field emission display device (FED or the like), a surface field emission display device (SED), electronic paper (a display device using electronic ink or an electrophoretic element), a plasma display device, a projection display device (a Grating Light Valve (GLV) display device, a display device having a Digital Micromirror Device (DMD), and a piezoelectric ceramic display.

The liquid crystal display device includes any one of a transmissive liquid crystal display device, a semi-transmissive liquid crystal display device, a reflective liquid crystal display device, a direct-view liquid crystal display device, a projection liquid crystal display device, and the like. These display devices may be display devices that display two-dimensional images, or may be stereoscopic display devices that display three-dimensional images. In particular, the display device of the present invention is preferably an organic EL display device or a touch panel display device, and particularly preferably an organic EL display device.

Examples

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, "part" or "%" is used, and unless otherwise specified, "part by mass" or "% by mass" is indicated, respectively. "

Example 1

[1] Preparation of resin film for polarizing plate

< preparation of resin film for polarizer 1 >

(support)

As the support, a polyethylene terephthalate film (PET film) was used: (TN 100 manufactured by Toyo-yo) has a release layer containing a non-silicone release agent, and the film thickness is 38. Mu.m.

(preparation of solution for resin film for polarizing plate 1)

The following components were mixed to obtain a solution for the resin film 1 for a polarizing plate.

860 parts by mass of methylene chloride (boiling point 41 ℃ C.)

40 parts by mass of methanol (boiling point 65 ℃ C.)

COP (ARTON (registered trademark) G7810: 100 parts by mass of a cycloolefin resin having a carboxylic acid group, mw:14 tens of thousands, manufactured by JSR (Co., ltd.)

Metal oxide particles: al (Al) ₂ O ₃ (SA 43A: manufactured by Nippon light metals Co., ltd.) 20 parts by mass

An antioxidant (Irganox (registered trademark) 1076: manufactured by BASF corporation: molecular weight 531) was added to the resin film for a polarizing plate in an amount of 0.002 mass%

The metal oxide was put into a mixed solvent (50:50) of methylene chloride and methanol, and 3 times of dispersion treatment was performed by using a Manton-Gaulin homogenizer. Then, the mixture was put into a dissolution vessel into which methylene chloride was put and stirred, and then resin was put into the vessel and stirred, to obtain a solution for the resin film 1 for a polarizing plate.

(preparation of resin film for polarizer 1)

After a solution for the resin film 1 for a polarizing plate was coated on the release layer of the support by a back coating method using a die, the following drying step was performed, thereby forming a resin film for a polarizing plate having a thickness of 6 μm, and obtaining a resin film 1 for a polarizing plate.

The first step: at 40℃for 1 minute

And a second step of: at 70℃for 1 minute

And a third step of: at 100℃for 1 minute

Fourth step: at 130℃for 2 minutes

The thickness of the resin film for a polarizing plate was measured using F20-UV (manufactured by FILMETRICS Co.) as a film thickness measuring system.

Further, in terms of the thermal conductivity of the film, the film was compressed by 10% of its thickness, sandwiched between the TO-3 heater case and the copper plate. Then, a power of 5W was applied to the copper heater case and the copper heater case was held for 4 minutes, and the temperature difference between the copper heater case and the copper plate was measured. The thermal conductivity was calculated by the following formula.

The ratio (particle diameter ratio) of the average primary particle diameter to the average secondary particle diameter of the metal oxide particles, which is represented by the average secondary particle diameter/average primary particle diameter, was calculated using the average particle diameter obtained by the following method.

In the sample prepared by the microtome, the primary particles (or the secondary particles) were observed by a transmission electron microscope (Hitachi H-7100FA type), and the diameter (so-called equivalent circle diameter) at which a circle having the same projected area was assumed was used as the primary particle diameter (or the secondary particle diameter). Then, the particle diameters of 1000 primary particles (or secondary particles) thus obtained were averaged, and the average value thereof was regarded as an average primary particle diameter (or average secondary particle diameter).

< preparation of resin films 2, 12 and 13 for polarizing plate >

The metal oxide particles were changed to ZnO (FINEX (registered trademark) 50: manufactured by Sakai chemical industry Co., ltd.) and CuO (FC) described in Table I, respectivelyO500: manufactured by gulch chemical Co., ltd.) and TiO ₂ (STR (registered trademark) 100N: manufactured by Sakai chemical industry Co., ltd.) resin films 2, 12 and 13 for polarizing plates were produced in the same manner as the production of the resin film 1 for polarizing plates.

< preparation of resin film for polarizer 3 >

A resin film 3 for a polarizing plate was produced in the same manner as the production of the resin film 1 for a polarizing plate except that the solution for a resin film for a polarizing plate was changed to the following solution.

(preparation of rubber particle R1)

Rubber particles R1 prepared by the following method were used.

The following materials were charged into an 8L polymerization apparatus equipped with a stirrer.

180 parts by mass of deionized water

Polyoxyethylene lauryl ether phosphoric acid 0.002 mass portions

Boric acid 0.473 parts by mass

Sodium carbonate 0.047 mass portions

Sodium hydroxide 0.008 mass portion

After the inside of the polymerization machine was sufficiently replaced with nitrogen gas, 0.021 parts by mass of potassium persulfate was charged as a 2% aqueous solution at an internal temperature of 80 ℃. Next, a mixed solution in which 0.07 mass part of polyoxyethylene lauryl ether phosphate was added to 21 mass parts of a monomer mixture (c') composed of 84.6 mass% of methyl methacrylate, 5.9 mass% of butyl acrylate, 7.9 mass% of styrene, 0.5 mass% of allyl methacrylate, and 1.1 mass% of n-octylmercaptan was continuously added to the solution over 63 minutes. Further, the polymerization reaction was continued for 60 minutes, whereby the innermost hard polymer (c) was obtained.

Then, 0.021 parts by mass of sodium hydroxide and 0.062 parts by mass of potassium persulfate were added as 2% by mass of an aqueous solution, respectively. Subsequently, a mixed solution of 0.25 part by mass of polyoxyethylene lauryl ether phosphate was continuously added to 39 parts by mass of a monomer mixture (a') composed of 80.0% by mass of butyl acrylate, 18.5% by mass of styrene and 1.5% by mass of allyl methacrylate over 117 minutes. After completion of the addition, 0.012 parts by mass of potassium persulfate was added to the 2% by mass aqueous solution, and the polymerization was continued for 120 minutes to obtain a soft layer (layer composed of the acrylic rubbery polymer (a)).

Then, 0.04 parts by mass of potassium persulfate was added to the 2% by mass aqueous solution, and 26.1 parts by mass of a monomer mixture (b') composed of 97.5% by mass of methyl methacrylate and 2.5% by mass of butyl acrylate was continuously added thereto over 78 minutes. Further, the polymerization was continued for 30 minutes to obtain a polymer (b).

The obtained polymer was put into a 3 mass% aqueous sodium sulfate solution and salted out to solidify. Subsequently, dehydration was repeated, followed by washing and drying, whereby acrylic graft copolymer particles (rubber particles R1) having a three-layer structure were obtained. The average particle diameter of the obtained rubber particles R1 was 200nm.

The average particle diameter of the rubber particles was measured by the following method.

The dispersion particle diameter of the rubber particles in the obtained dispersion was measured by a ZETA potential and particle diameter measuring system (ELSZ-2000 ZS, manufactured by Otsuka electronics Co., ltd.).

(preparation of solution for resin film 3 for polarizing plate)

The following components were mixed to obtain a solution 5 for a resin film for a polarizing plate.

800 parts by mass of methylene chloride (boiling point 41 ℃ C.)

Acrylic acid: MMA/PMI/MADA copolymer (60/20/20 mass ratio), mw:150 ten thousand, tg:137 ℃ (abbreviated as MMA: methyl methacrylate, PMI: phenylmaleimide, and MADA: adamantyl acrylate) 80 parts by mass

Rubber particle R1 20 parts by mass

Dispersing agent (sodium polyoxyethylene lauryl ether phosphate: molecular weight 332)

An amount of 0.006% by mass was added to the resin film for a polarizing plate

< preparation of resin films 4 to 6 and 11 for polarizing plate >

Polarizing plate resin films 4 to 6 and 11 were produced in the same manner as in production of the polarizing plate resin film 1 except that the thickness of the polarizing plate resin film was changed to the thickness shown in table I.

< preparation of resin films for polarizer 7 to 10 >

Resin films 7 to 10 for polarizing plates were produced in the same manner as the production of the resin film 1 for polarizing plates except that the number of treatments with a Manton-Gaulin homogenizer was changed and the particle diameter ratio of the metal oxide particles was changed.

< preparation of resin films 14 to 16 for polarizing plate >

A resin film 14 for a polarizing plate was produced in the same manner as the production of the resin film 1 for a polarizing plate except that 5 parts by mass of the compound 1 shown below and 0.005 part by mass of sulfuric acid were used instead of the metal oxide particles. The thicknesses of the resin films for polarizing plates 15 and 16 were changed to those shown in table II.

< preparation of resin films 17 to 20 for polarizing plate >

Resin films 18 to 20 for polarizing plates were produced in the same manner as the production of the resin film 14 for polarizing plates except that the addition amount of sulfuric acid was changed so that the content of sulfate ions became the content shown in table II. Sulfuric acid is not added to the resin film 17 for a polarizing plate.

< preparation of resin film for polarizer 21 >

A resin film 21 for a polarizing plate was produced in the same manner as the production of the resin film 14 for a polarizing plate except that the addition amount of the compound 1 and the sulfate ion content were changed as shown in table II.

< preparation of resin film for polarizer 22 >

A resin film 22 for a polarizing plate was produced in the same manner as the production of the resin film 3 for a polarizing plate, except that 5 parts by mass of the compound 1 shown below was used instead of the metal oxide particles.

< preparation of resin films 23 to 32 and 34 to 36 for polarizing plate >

Except that the compound 1 was changed to the compound shown below, the resin films 23 to 32 and 34 to 36 for polarizing plates were produced in the same manner as the production of the resin film 14 for polarizing plates.

< preparation of resin film for polarizer 33 >

A resin film for polarizing plate 33 was produced in the same manner as the production of the resin film for polarizing plate 14 except that the compound 1 was changed to the compound 7 shown below and the thickness of the resin film for polarizing plate was changed to 20 μm.

The structural formula of the organic compound used (commercially available products and synthetic products of this company obtained by a known method) is shown below.

As a commercially available product, 18-crown 6-ether manufactured by Tokyo chemical industry Co., ltd was used as compound 6, and acetic acid manufactured by Fuji photo-pure chemical Co., ltd was used as compound 10.

The synthesis of this company is performed, for example, by referring to the method described in paragraph 0083 of japanese patent No. 5919227.

[ chemical formula 22]

[ chemical formula 23]

Compounds 1 to 9 and 13 to 14 function as inhibitors of iodine migration. In addition, the compound 10 does not satisfy the definition of the non-organic acid of the present invention and does not function as an iodine migration inhibitor. Regarding the compounds 11 and 12, the delta P (polar force) of HSP value was 5 to 9MPa ^0.5 Is out of range, and does not function as an iodine migration inhibitor.

The HSP values (δP and δD) of the compounds shown in Table II are calculated values based on HSPIP 5th edition.

The content of sulfate ions in the total mass of the solid content of the resin film for a polarizing plate was measured by a capillary electrophoresis apparatus.

Further, conditions for capillary electrophoresis are as follows.

Capillary electrophoresis device: CAPI-3100 (manufactured by Otsuka electronics company)

Capillary tube: fused silica capillary tube with unmodified inner surface (GL Science Co., ltd., inner diameter of 50 μm, length of 62.5cm, effective length of 50 cm)

Sample injection: drop method (2.5 cmx30 seconds)

Applying a voltage: 25kV (kV)

Detection wavelength: 200nm

Electrophoresis liquid: 50mM boric acid buffer (pH 10.5)

[2] Preparation of a polarizer layer

< preparation of polarizer layer (3 μm)

Polyvinyl alcohol films having a thickness of 20 μm were swollen in water at 35 ℃. The resulting film was immersed in an aqueous solution containing 0.075g of iodine, 5g of potassium iodide and 100g of water for 60 seconds, and further immersed in an aqueous solution containing 3g of potassium iodide, 7.5g of boric acid and 100g of water at 45 ℃. The obtained film was uniaxially stretched at a stretching temperature of 55℃and a stretching ratio of 5 times. The uniaxially stretched film was washed with water and then dried to form a polarizer layer having a thickness of 3. Mu.m.

< preparation of polarizer layer (7 μm)

Polyvinyl alcohol films 40 μm thick were swollen in water at 35 ℃. The resulting film was immersed in an aqueous solution containing 0.075g of iodine, 5g of potassium iodide and 100g of water for 60 seconds, and further immersed in an aqueous solution containing 3g of potassium iodide, 7.5g of boric acid and 100g of water at 45 ℃. The obtained film was uniaxially stretched at a stretching temperature of 55℃and a stretching ratio of 5 times. The uniaxially stretched film was washed with water and then dried to form a polarizer layer having a thickness of 7. Mu.m.

< preparation of polarizer layer (13 μm)

Polyvinyl alcohol films 60 μm thick were swollen in water at 35 ℃. The resulting film was immersed in an aqueous solution containing 0.075g of iodine, 5g of potassium iodide and 100g of water for 60 seconds, and further immersed in an aqueous solution containing 3g of potassium iodide, 7.5g of boric acid and 100g of water at 45 ℃. The obtained film was uniaxially stretched at a stretching temperature of 55℃and a stretching ratio of 5 times. The uniaxially stretched film was washed with water and then dried to form a polarizer layer having a thickness of 13. Mu.m.

< preparation of polarizer layer (20 μm)

Polyvinyl alcohol films having a thickness of 100 μm were swollen in water at 35 ℃. The resulting film was immersed in an aqueous solution containing 0.075g of iodine, 5g of potassium iodide and 100g of water for 60 seconds, and further immersed in an aqueous solution containing 3g of potassium iodide, 7.5g of boric acid and 100g of water at 45 ℃. The obtained film was uniaxially stretched at a stretching temperature of 55℃and a stretching ratio of 5 times. The uniaxially stretched film was washed with water and then dried to form a polarizer layer having a thickness of 20. Mu.m.

[3] Preparation of polarizer

Polarizing plates 1 to 29 were prepared by bonding a polarizer layer (7 μm) and a protective layer to the polarizing plate resin films 1 to 36 via the following water-soluble adhesive liquid, respectively. For the resin film 1 for polarizing plate, polarizing plates 1-1, 1-2, 1-3 and 1-4 each having polarizing layers of thicknesses 7, 3, 13 and 20 μm were prepared. Similarly, polarizers 14-1, 14-2 and 14-3 each having polarizer layers of thicknesses 7, 3 and 20 μm bonded thereto were prepared for the resin film 14 for a polarizer.

(preparation of Water-soluble adhesive liquid)

The following components were mixed and defoamed to prepare a water-soluble adhesive liquid.

100 parts by mass of pure water

7.5 parts by mass of "EPOROS WS-300", manufactured by NIPPON SHOKUBIAI, inc

0.1 part by mass of "Cross SLINKER CL-427" manufactured by MENADIONA Co

In the production of a polarizing plate, the surface of the resin film for a polarizing plate on the adhesion side was subjected to corona discharge treatment at a corona output intensity of 2.0kW and a linear velocity of 18 m/min, and the water-soluble adhesive liquid thus produced was applied to the corona discharge treated surface by a bar coater so that the thickness after drying became about 3 μm, and then dried at 50 ℃, 60 ℃ and 70 ℃ for 60 seconds, respectively, followed by lamination. Similarly, KC2CT-W (manufactured by Konikoku Meida Co., ltd.) was bonded to the surface of the polarizer layer to which the resin film for polarizing plate was not bonded, and the support of the resin film for polarizing plate was peeled off to obtain polarizing plates 1 to 36.

Evaluation (evaluation)

The obtained polarizing plate was incorporated into a display device, and after the backlight was continuously turned on for 1 week at 80 ℃ and 55% rh, a part of the polarizing plate was removed, and the following adhesion was evaluated. The remaining polarizer portions were evaluated for contrast as follows.

(1) Front contrast evaluation

The luminance in the white display state and the black display state of the liquid crystal display device were measured from the normal direction of the display screen of the liquid crystal display device using a device "CS-2000" manufactured by KONICA MINOLTASENSING company, respectively, by which light having a wavelength of 550nm was irradiated. Then, the obtained value is substituted into the following equation, and the frontal Contrast (CR) is calculated.

Front Contrast (CR) = (luminance in white display state) - (luminance in black display state)

The value of the front contrast after continuous lighting for 1 week was evaluated based on the following criteria. After the lighting treatment, whether or not the front CR was similarly developed was evaluated based on the following criteria, and Δ was set to be good or higher.

◎:900≤CR

○:850≤CR<900

△:800≤CR<850

×:800>CR

(2) Evaluation of adhesive force

For the obtained sample, a peeling test was performed at a peeling speed of 300 mm/min in a direction of 180 ° at the interface between the resin film for a polarizing plate and the polarizer layer. The peel strength (adhesive strength) [ N/25mm ] at this time was measured using "Autograph AGS-50NX" manufactured by Shimadzu corporation. As for the value of the adhesion force, 3 samples (N number=3) were prepared, and an average value of 3 values was adopted. In the present evaluation, the peeling state was visually observed, and the peeling strength at the time of peeling at the interface between the resin film for polarizing plate and the adhesive layer was used.

The adhesion values were evaluated based on the following criteria. After the lighting treatment, whether or not the adhesion was similarly developed was evaluated based on the following criteria, and Δ or more was set to be good.

And (3) the following materials: film material breakage and failure to measure adhesion

O: the adhesion force exceeds 2.0N/25mm

Delta: the adhesive force is in the range of 1.0-2.0N/25 mm

X: the adhesive force is less than 1.0N/25mm

The evaluation results are shown in tables I and II below.

TABLE 1

TABLE 2

From the above results, it was found that in the case of the polarizing plate provided with the resin film for a polarizing plate of the present invention, the decrease in adhesion and the deterioration in contrast caused by the heat generation of the semiconductor substrate were suppressed.

Industrial applicability

The use of the resin film for a polarizing plate of the present invention for a polarizing plate in a display device can suppress a decrease in adhesion and a deterioration in contrast caused by heat generation of a semiconductor substrate, and thus can suppress a decrease in durability caused by heat generation of a communication device corresponding to the fifth generation mobile communication system (5G).

Symbol description

B110 Support body

B200 Manufacturing apparatus

B210 Supply part

B220 Coating part

B230 Drying section

B240 Cooling part

B250 Winding part

1. Resin film for polarizing plate

2. Adhesive layer

3. Polarizer layer

4. Protective layer

10. Polarizing plate

Claims

1. A resin film for a polarizing plate, which is used for a polarizing plate having at least a polarizer layer containing iodine,

the resin film for a polarizing plate comprises at least a thermoplastic resin and an iodine migration inhibitor,

the film thickness is 1 μm or more and less than 15 μm.

2. The resin film for a polarizing plate according to claim 1, wherein,

the iodine movement inhibitor is metal oxide particles,

the resin film for a polarizing plate has a thermal conductivity in the range of 0.2 to 0.6W/mK.

3. The resin film for a polarizing plate according to claim 2, wherein,

the ratio of the average primary particle diameter to the average secondary particle diameter of the metal oxide particles satisfies the following formula (1),

4. The resin film for a polarizing plate according to claim 1, wherein,

the iodine movement inhibitor is a non-organic acid, and,

the delta P (polar force) of the hansen solubility parameter (HSP value) of the non-organic acid is 5-9 MPa ^0.5 Within a range of (2).

5. The resin film for a polarizing plate according to claim 4, wherein,

the ratio of δd (dispersion force) to δp (polar force) of the HSP value of the non-organic acid satisfies the following formula (2),

formula (2): 2< δd (dispersion force)/δp (polar force) <4.

6. The resin film for a polarizing plate according to claim 4 or 5, wherein,

the iodine movement inhibitor further comprises sulfate ions, and,

the sulfate ion content is in the range of 1 to 100 mass ppm relative to the total mass of the solid content of the resin film for a polarizing plate.

7. The resin film for a polarizing plate according to any one of claims 1 to 6, wherein,

the thermoplastic resin is a cycloolefin resin.

8. A method for producing the resin film for a polarizing plate according to any one of claims 1 to 7, wherein the method comprises:

and a step of coating a solution containing a thermoplastic resin and an iodine migration inhibitor on the release layer using the resin film having the release layer as a support.

9. A polarizing plate having an adhesive layer and a polarizer layer on a resin film, wherein,

the polarizing plate comprises the resin film for a polarizing plate according to any one of claims 1 to 7 as the resin film.

10. The polarizing plate according to claim 9, wherein,

the thickness of the polarizer layer is in the range of 4-15 μm.

11. A display device includes a polarizing plate, wherein,

the display device includes the polarizing plate according to claim 9 or 10 as the polarizing plate.