TW202020028A - Retardation film, polarizing plate with retardation layers, and method for manufacturing retardation film having excellent property in blocking resistance during the rolling process - Google Patents

Abstract

The present invention provides a retardation film excellent in blocking resistance. The retardation film of the present invention includes a stretched resin film, and at least one surface of the retardation film has an arithmetic mean roughness Ra of 2 nm or more, and a haze value of less than 2.6%. The thickness and optical characteristics of the retardation film can be set according to the usage and purpose.

Description

Phase difference film, polarizing plate with phase difference layer, and method for manufacturing phase difference film

The invention relates to a method for manufacturing a retardation film, a polarizing plate with a retardation layer, and a retardation film.

In recent years, with the spread of thin displays, image display devices (organic EL display devices) equipped with organic EL panels have been proposed. Organic EL panels have a highly reflective metal layer, which is prone to problems such as external light reflection or background reflection. Therefore, it is known to prevent these problems by providing a polarizing plate (circular polarizing plate) with a retardation layer on the viewing side. In addition, it is known to improve the viewing angle by providing a polarizing plate with a retardation layer on the viewing side of the liquid crystal display panel. As a general polarizing plate with a retardation layer, there is known a polarizing plate formed by laminating a retardation film and a polarizing element such that the retardation axis and the absorption axis are at a specific angle (for example, 45°) corresponding to the application. . In addition, as a typical retardation film, a retardation film in which the retardation axis is expressed in the extending direction by stretching the resin film is known (Patent Document 1). However, when making a long strip of retardation film and winding it, sometimes adhesion occurs. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3325560

[Problems to be solved by the invention]

The present invention has been made to solve the aforementioned problems, and an object thereof is to provide a retardation film excellent in blocking resistance, a polarizing plate with a retardation layer provided with such a retardation film, and a method of manufacturing the retardation film. [Technical means to solve the problem]

The retardation film of the present invention includes a stretched resin film, and the arithmetic average roughness Ra of at least one surface is 2 nm or more, and the haze value is less than 2.6%. In one embodiment, the retardation film has a ridge shape along a direction orthogonal to the extension axis. In one embodiment, the resin film in the retardation film is a polycarbonate resin film. In one embodiment, the retardation film includes a uniaxially stretched resin film. According to another aspect of the present invention, a polarizing plate with a retardation layer is provided. The polarizing plate with a retardation layer includes a polarizing plate and a retardation layer, and the retardation layer includes the retardation film. According to another aspect of the present invention, a method for manufacturing the above-mentioned retardation film is provided. The manufacturing method includes: immersing the above-mentioned stretched resin film in a liquid containing good and poor solvents relative to the above-mentioned resin film. In one embodiment, the immersion time of the resin film in the liquid is 1 second to 110 seconds. [Effect of invention]

According to the embodiment of the present invention, a retardation film can be realized, which is a retardation film including a stretched resin film, and the arithmetic average roughness Ra of at least one surface is 2 nm or more, and the haze value does not reach 2.6%, resulting in excellent blocking resistance.

Hereinafter, the embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

A. retardation film The retardation film according to an embodiment of the present invention includes a stretched resin film. The arithmetic average roughness Ra of at least one surface of the retardation film is 2 nm or more, and the haze value is less than 2.6%. Thus, the above-mentioned retardation film can improve blocking resistance without impairing optical characteristics (for example, light transmittance) compared with the previous retardation film. Therefore, according to the phase difference film of the present embodiment, it is possible to prevent sticking at the time of winding without performing anti-blocking treatment or without interposing a step paper.

The arithmetic average roughness Ra of at least one surface of the retardation film is preferably 2 nm to 5 nm, more preferably 2 nm to 4 nm, and further preferably 2 nm to 3 nm. The haze value of the retardation film is preferably 0.1% to 2.6%, more preferably 0.1% to 2.0%, still more preferably 0.1% to 1.3%, and particularly preferably 0.1% to 1.1%.

The resin film constituting the retardation film is typically a polycarbonate resin film. The retardation film typically includes a uniaxially stretched resin film. The retardation film typically has a ridge shape along a direction orthogonal to the extension axis. The arithmetic average roughness Ra and the haze value of the retardation film can be realized by the ridge shape. Such a ridge shape can be formed by, for example, the dipping treatment described in Section C described later.

The thickness and optical characteristics of the retardation film (in-plane retardation, thickness direction retardation, wavelength dispersion characteristics, etc.) can be appropriately set according to the application and purpose. For example, in the case of using a retardation film as the λ/4 plate, the in-plane retardation is preferably 100 nm to 160 nm.

B. Resin film The retardation film includes the stretched resin film as described above. As the resin constituting the resin film, any suitable resin can be used as long as the obtained retardation film satisfies the above characteristics, and examples thereof include polycarbonate-based resins, cyclic olefin-based resins, cellulose-based resins, and polyesters. Resin, polyvinyl alcohol resin, polyamide resin, polyimide resin, polyether resin, polystyrene resin, acrylic resin, polyester carbonate resin. Among these, polycarbonate-based resins can be suitably used.

As the above polycarbonate resin, any suitable polycarbonate resin can be used as long as the effect of the present invention can be obtained. Preferably, the polycarbonate resin includes a structural unit derived from a fluorene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structural unit selected from the group consisting of alicyclic diol, alicyclic dimethanol, and diethyl Structural unit of at least one dihydroxy compound in the group consisting of diol, triethylene glycol or polyethylene glycol, and alkylene glycol or spirodiol. Preferably, the polycarbonate resin contains a structural unit derived from a fluorene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structural unit derived from an alicyclic dimethanol and/or derived from diethylenedioxide Structural units of alcohol, triethylene glycol, or polyethylene glycol; further preferably, structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and diethylene glycol , The structural unit of triethylene glycol or polyethylene glycol. The polycarbonate resin may contain structural units derived from other dihydroxy compounds as needed. In addition, the details of the polycarbonate resin that can be suitably used in the present invention are described in, for example, Japanese Patent Laid-Open No. 2014-10291 and Japanese Patent Laid-Open No. 2014-26266, and the description is incorporated by reference in this specification .

(上述通式(1)中，R₁ ～R₄ 分別獨立地表示氫原子、經取代或未經取代之碳數為1～碳數為20之烷基、經取代或未經取代之碳數為6～碳數為20之環烷基、或者經取代或未經取代之碳數為6～碳數為20之芳基，X表示經取代或未經取代之碳數為2～碳數為10之伸烷基、經取代或未經取代之碳數為6～碳數為20之伸環烷基、或者經取代或未經取代之碳數為6～碳數為20之伸芳基，m及n分別獨立地為0～5之整數)In one embodiment, a polycarbonate-based resin containing a unit structure derived from a dihydroxy compound represented by the following general formula (1) can be used. [Chem 1]

(In the above general formula (1), R ₁ to R ₄ each independently represent a hydrogen atom, a substituted or unsubstituted alkyl group having a carbon number of 1 to 20, a substituted or unsubstituted carbon number Is a cycloalkyl group having 6 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and X represents a substituted or unsubstituted carbon atom having 2 to 2 carbon atoms 10 alkylene group, substituted or unsubstituted carbon number 6 to carbon number 20 alkylene group, or substituted or unsubstituted carbon number 6 to carbon number 20 aryl group, m and n are independently integers from 0 to 5)

Specific examples of the dihydroxy compound represented by the general formula (1) include 9,9-bis(4-hydroxyphenyl)fluorene and 9,9-bis(4-hydroxy-3-methylphenyl) Fluorene, 9,9-bis(4-hydroxy-3-ethylphenyl) fluorene, 9,9-bis(4-hydroxy-3-n-propylphenyl) fluorene, 9,9-bis(4-hydroxy -3-isopropylphenyl) fluorene, 9,9-bis(4-hydroxy-3-n-butylphenyl) fluorene, 9,9-bis(4-hydroxy-3-second butylphenyl) Fluorene, 9,9-bis(4-hydroxy-3-t-butylphenyl) fluorene, 9,9-bis(4-hydroxy-3-cyclohexylphenyl) fluorene, 9,9-bis(4- Hydroxy-3-phenylphenyl) fluorene, 9,9-bis(4-(2-hydroxyethoxy)phenyl) fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3 -Methylphenyl) fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-isopropylphenyl) fluorene, 9,9-bis(4-(2-hydroxyethoxy )-3-isobutylphenyl) fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-third-butylphenyl) fluorene, 9,9-bis(4-(2 -Hydroxyethoxy)-3-cyclohexylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene, 9,9-bis(4- (2-Hydroxyethoxy)-3,5-dimethylphenyl) fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-tert-butyl-6-methylbenzene Group) fluorene, 9,9-bis(4-(3-hydroxy-2,2-dimethylpropoxy)phenyl) fluorene, etc.

In addition to the structural unit derived from the dihydroxy compound, the polycarbonate-based resin may also include isosorbide, isomannitol, isoiditol, spirodiol, dioxanediol, and dioxane. Structural units of dihydroxy compounds such as ethylene glycol (DEG), triethylene glycol (TEG), polyethylene glycol (PEG), and bisphenols.

The details of the polycarbonate-based resin containing a structural unit derived from a dihydroxy compound are described in, for example, Japanese Patent No. 5204200, Japanese Patent Laid-Open No. 2012-67300, Japanese Patent No. 3325560, WO2014/061677, and the like. The description of this patent document is incorporated by reference in this specification.

(上述通式(2)及上述通式(3)中，R₅ 及R₆ 分別獨立地為直接鍵、經取代或未經取代之碳數為1～4之伸烷基(較佳為主鏈上之碳數為2～3之伸烷基)。R₇ 為直接鍵、經取代或未經取代之碳數為1～4之伸烷基(較佳為主鏈上之碳數為1～2之伸烷基)。R₈ ～R₁₃ 分別獨立地為氫原子、經取代或未經取代之碳數為1～10(較佳為1～4、更佳為1～2)之烷基、經取代或未經取代之碳數為4～10(較佳為4～8、更佳為4～7)之芳基、經取代或未經取代之碳數為1～10(較佳為1～4、更佳為1～2)之醯基、經取代或未經取代之碳數為1～10(較佳為1～4、更佳為1～2)之烷氧基、經取代或未經取代之碳數為1～10(較佳為1～4、更佳為1～2)之芳氧基、經取代或未經取代之碳數為1～10(較佳為1～4、更佳為1～2)之醯氧基、經取代或未經取代之胺基、經取代或未經取代之碳數為1～10(較佳為1～4)之乙烯基、經取代或未經取代之碳數為1～10(較佳為1～4)之乙炔基、具有取代基之硫原子、具有取代基之矽原子、鹵素原子、硝基或氰基。R₈ ～R₁₃ 中之相鄰之至少2個基亦可相互鍵結而形成環)In one embodiment, a polycarbonate-based resin containing oligomeric fluorene structural units can be used. Examples of the polycarbonate-based resin containing an oligomeric fluorene structural unit include resins containing a structural unit represented by the following general formula (2) and/or a structural unit represented by the following general formula (3). [Chem 2]

(In the above general formula (2) and the above general formula (3), R ₅ and R ₆ are each independently a direct bond, substituted or unsubstituted C 1-4 alkylene group (preferably mainly (The carbon number of the chain is 2 to 3 alkylene groups). R ₇ is a direct bond, substituted or unsubstituted carbon number of 1 to 4 alkylene groups (preferably the main chain carbon number is 1 ～2 alkylene group). R ₈ ～R ₁₃ are independently hydrogen atom, substituted or unsubstituted carbon number of 1-10 (preferably 1-4, more preferably 1-2) alkane Group, substituted or unsubstituted carbon number of 4-10 (preferably 4-8, more preferably 4-7) aryl group, substituted or unsubstituted carbon number of 1-10 (preferably Is 1-4, more preferably 1-2), alkoxy, substituted or unsubstituted carbon number of 1-10 (preferably 1-4, more preferably 1-2) alkoxy, The aryloxy group having a substituted or unsubstituted carbon number of 1 to 10 (preferably 1 to 4, more preferably 1 to 2), and a substituted or unsubstituted carbon number of 1 to 10 (preferably 1 ～4, more preferably 1～2) acetyloxy group, substituted or unsubstituted amine group, substituted or unsubstituted carbon number of 1-10 (preferably 1-4) vinyl, A substituted or unsubstituted C 1-10 (preferably 1 to 4) ethynyl group, a substituted sulfur atom, a substituted silicon atom, a halogen atom, a nitro group or a cyano group. R ₈ ~ At least two adjacent groups in R ₁₃ can also be bonded to each other to form a ring)

In one embodiment, the fluorene ring contained in the oligomeric fluorene structural unit has a structure in which R ₈ to R _{13 are} all hydrogen atoms, or has R ₈ and/or R ₁₃ selected from halogen atoms, acetyl groups, nitro, Any one of the cyano group and the sulfo group and R ₉ to R ₁₂ are hydrogen atoms.

The details of the polycarbonate resin containing the oligomeric fluorene structural unit are described in, for example, Japanese Patent Laid-Open No. 2015-212816. The description of this patent document is incorporated by reference in this specification.

In one embodiment, the retardation film is produced by uniaxially extending the resin film or uniaxially extending the fixed end. As a specific example of uniaxial extension of the fixed end, a method of extending the resin film in the width direction (lateral direction) while advancing the resin film in the longitudinal direction can be cited. The stretching magnification is preferably 1.1 times to 3.5 times.

In another embodiment, the retardation film is produced by continuously extending the elongated resin film obliquely in a direction at an angle θ with respect to the longitudinal direction. By adopting oblique stretching, a long stretched film having an alignment angle of angle θ (the slow phase axis in the direction of angle θ) with respect to the longitudinal direction of the film can be obtained, for example, when laminated with a polarizing element Roll-to-roll can simplify manufacturing steps.

As the stretching machine used for the inclined stretching, for example, a tenter type stretching machine which can apply a feed force, a stretching force or a traction force at different speeds in the lateral direction and/or the longitudinal direction can be applied. Tenter-type stretching machines include lateral uniaxial stretching machines, simultaneous biaxial stretching machines, etc., but any suitable stretching machine can be used as long as the elongated resin film can be continuously stretched obliquely.

C. Manufacturing method of retardation film The retardation film described in the above item A can be manufactured by the manufacturing method of the present invention. The manufacturing method of the present invention includes immersing the stretched resin film in a liquid containing good and poor solvents relative to the resin film. The above-mentioned stretched resin film is the resin film described in the above item B.

As mentioned above, the liquid includes good and poor solvents relative to the resin film. As the good solvent and the poor solvent, as long as the retardation film described in the above item A is obtained, any appropriate solvent can be used. Examples of good solvents include ethyl acetate and methyl ethyl ketone. Examples of poor solvents include isopropyl alcohol. The quality of the good solvent and the poor solvent is better: 45:55～55:45. If the ratio of the good solvent is too large, the resin film may be dissolved. If the ratio of the poor solvent is too large, the effect on the surface of the resin film may become insufficient, and the ridge shape as described above may not be formed.

The immersion time of the resin film in the above liquid is preferably 1 second to 110 seconds, more preferably 2 seconds to 60 seconds, and still more preferably 3 seconds to 30 seconds. By immersing the stretched resin film in the above-mentioned liquid, a concave-convex shape can be formed on the surface of the resin film over time (typically, a ridge shape along a direction orthogonal to the extension axis of the resin film) . Thus, the arithmetic mean roughness Ra and haze value of the surface of the resin film can be increased according to the immersion time. Therefore, by appropriately setting the immersion time of the resin film in the above liquid, a retardation film having a desired arithmetic average roughness Ra and haze value can be obtained.

In one embodiment, the resin film is immersed in the liquid and then dried. The drying conditions can be appropriately set, for example, the drying temperature is 80°C to 120°C, and the drying time is 30 seconds to 3 minutes.

D. Polarizing plate with retardation layer The retardation film described in the above item A can be applied to an optical member such as a polarizing plate with a retardation layer. Therefore, the present invention includes a polarizing plate with a retardation layer having the retardation film. The polarizing plate with a retardation layer according to an embodiment of the present invention includes a polarizing plate and a retardation layer including the retardation film. The angle formed by the absorption axis of the polarizing plate and the retardation axis of the retardation film can be appropriately set according to the application and purpose. The aforementioned angle is, for example, 38° to 52°.

The polarizing plate typically has a polarizing element and a protective layer disposed on at least one side of the polarizing element. The polarizing element is typically an absorption-type polarizing element.

As the polarizing element, any appropriate polarizing element can be used. For example, the resin film forming the polarizing element may be a single-layer resin film or a laminate of two or more layers.

Specific examples of the polarizing element including a single-layer resin film include hydrophilic polymers such as polyvinyl alcohol (PVA)-based films, partially formalized PVA-based films, and ethylene-vinyl acetate copolymer-based partially saponified films. The film is subjected to a polyene-based alignment film such as a polarizing element obtained by dyeing treatment and elongation treatment using a dichroic substance such as iodine or a dichroic dye, a dehydration treatment product of PVA, or a dechlorination treatment product of polyvinyl chloride. In terms of excellent optical characteristics, it is preferable to use a polarizing element obtained by dyeing a PVA-based film with iodine and uniaxially stretching.

The above dyeing with iodine is performed by, for example, immersing the PVA-based film in an aqueous iodine solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The extension can be carried out after dyeing, or it can be carried out while dyeing. In addition, dyeing may be performed after stretching. The PVA-based film is subjected to swelling treatment, cross-linking treatment, washing treatment, drying treatment, etc. as needed. For example, by immersing the PVA film in water for washing before dyeing, not only can the dirt or anti-blocking agent on the surface of the PVA film be washed away, but also the PVA film can be swollen to prevent uneven dyeing.

As a specific example of the polarizing element obtained by using the laminate, a laminate or resin substrate using a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate and coated on A polarizing element obtained by a laminate of PVA resin layers on the resin substrate. Details of the manufacturing method of such a polarizing element are described in Japanese Patent Laid-Open No. 2012-73580, for example. The entire contents of this gazette are cited in this specification as a reference.

The thickness of the polarizing element is, for example, 1 μm to 80 μm. In one embodiment, the thickness of the polarizing element is preferably 1 μm to 25 μm, more preferably 3 μm to 10 μm, and particularly preferably 3 μm to 8 μm. If the thickness of the polarizing element is within such a range, curling during heating can be well suppressed and good appearance durability during heating can be obtained.

The protective layer is formed of any suitable protective film that can be used as a film for protecting the polarizing element. Specific examples of the material that becomes the main component of the protective film include cellulose-based resins such as triacetyl cellulose (TAC), or polyester-based, polyvinyl alcohol-based, polycarbonate-based, and polyamide-based , Polyimide-based, polyether-based, poly-based, polystyrene-based, polynorbornene-based, polyolefin-based, (meth)acrylic, and acetate-based transparent resins. In addition, thermosetting resins such as (meth)acrylic resins, urethane resins, (meth)acrylic acid resins, epoxy resins, and silicone resins, or ultraviolet curing resins, etc. may be mentioned. . In addition to this, for example, vitreous-based polymers such as siloxane-based polymers can be cited. In addition, the polymer film described in Japanese Patent Laid-Open No. 2001-343529 (WO01/37007) can also be used. As the material of the film, for example, a thermoplastic resin containing a substituted or unsubstituted amide imide group on the side chain and a thermoplastic resin having a substituted or unsubstituted phenyl group and a nitrile group on the side chain can be used Examples of the resin composition include resin compositions containing an alternating copolymer containing isobutylene and N-methylmaleimide and an acrylonitrile-styrene copolymer. The polymer film may be, for example, an extrusion-molded product of the above resin composition.

The thickness of the protective film is preferably 10 μm to 100 μm. The protective film may be laminated on the polarizing element through an adhesive layer (specifically, an adhesive layer or an adhesive layer), or may be laminated on the polarizing element in close contact (without an adhesive layer). A surface treatment layer such as a hard coat layer, an anti-glare layer, and an anti-reflection layer can be formed on the protective film disposed on the outermost surface of the polarizing plate with a retardation layer as needed. Examples

Hereinafter, the present invention will be specifically described by examples, but the present invention is not limited by these examples. In addition, the measurement method and evaluation method of each characteristic are as follows. (1) The arithmetic average roughness Ra of the surface of the retardation film Using the scanning probe microscope "Nanoscope IV" AFM tapping mode manufactured by Veeco Instruments, the arithmetic mean roughness Ra in the area of 1 μm×1 μm on the surface of the phase difference film was measured. (2) Haze value According to the method specified in JIS 7136, a haze meter (made by Murakami Color Science Research Institute Co., Ltd., trade name "HM-150") was used for measurement. (3) Blocking resistance In a state where two retardation films are overlapped, by sliding the retardation film disposed on the upper side, blocking resistance was evaluated according to the following criteria. ○ The retardation film slides smoothly. × The phase difference films are in close contact with each other, and the phase difference films arranged on the upper side have no slippage. (4) Brightness The surface of the phase difference layer side of the polarizing plate with a phase difference layer was bonded to the visible side of the organic EL panel of an organic EL display device (manufactured by LG Display, product name "55C7P") via an adhesive layer to obtain an organic EL panel. A white image was displayed on the organic EL panel, and the front brightness was measured using a spectroradiometer (trade name "BM-9A") manufactured by TOPCON. (5) Reflectivity A black image was displayed on the organic EL panel of (4) above, and the front reflectance was measured using a spectrophotometer (CM-2600d) manufactured by Konica Minolta.

[Example 1] 1. Production of polarizer On one side, a long roll of a polyvinyl alcohol film (manufactured by Kuraray, product name "PE6000") with a thickness of 60 μm is uniaxially stretched in the long direction by a roll stretching machine so that it becomes 5.9 times in the long direction On one side, swelling, dyeing, cross-linking, and washing treatments were simultaneously performed, and finally drying treatment was performed, thereby manufacturing a polarizing element having a thickness of 22 μm. Specifically, the swelling treatment is extended to 2.2 times while being treated with pure water at 20°C. Next, the dyeing treatment was extended to 1.4 times while being treated in an aqueous solution at 30° C. with a weight ratio of iodine to potassium iodide whose iodine concentration was adjusted so that the transmittance of the polarizing film produced became 43.0% to 1:7. Furthermore, the cross-linking treatment is a two-stage cross-linking treatment, and the first-stage cross-linking treatment is extended to 1.2 times while being treated in an aqueous solution in which boric acid and potassium iodide are dissolved at 40°C. The boric acid content of the aqueous solution of the crosslinking treatment in the first stage is 5.0% by weight, and the potassium iodide content is set to 3.0% by weight. The cross-linking treatment in the second stage is extended to 1.6 times while being treated in an aqueous solution in which boric acid and potassium iodide are dissolved at 65°C. The boric acid content of the aqueous solution of the cross-linking treatment in the second stage is 4.3% by weight, and the potassium iodide content is set to 5.0% by weight. In addition, the washing treatment is performed in an aqueous solution of potassium iodide at 20°C. The potassium iodide content of the washed aqueous solution is set to 2.6% by weight. Finally, the drying treatment was performed at 70°C for 5 minutes to obtain a polarizing element. On one side of the obtained polarizing element, a single side of the TAC film bonded with a polyvinyl alcohol-based adhesive has a low reflection TAC film (thickness) of a hard coating (HC) layer formed by a low reflection hard coating process : 72 μm, manufactured by Dainippon Printing Co., Ltd., product name "DSG-03HL"), and obtained a polarizing plate with a protective film/polarizing element configuration.

2. Production of retardation film and polarizing plate with retardation layer A batch polymerization apparatus including 2 vertical reactors equipped with a stirring wing and a reflux cooler controlled at 100°C was used for polymerization. Injected bis[9-(2-phenoxycarbonylethyl)fluorene-9-yl]methane (Compound 3) 29.60 parts by mass (0.046 mol), ISB 29.21 parts by mass (0.200 mol), SPG 42.28 parts by mass (0.139 mol ), DPC 63.77 parts by mass (0.298 mol) and 1.19×10 ⁻² parts by mass (6.78×10 ⁻⁵ mol) of calcium acetate monohydrate as a catalyst. After the reduced-pressure nitrogen was replaced in the reactor, heating was performed by a heat medium, and stirring was started when the internal temperature became 100°C. After 40 minutes from the start of the temperature increase, the internal temperature was adjusted to 220°C, and the pressure was controlled to maintain the temperature. At the same time, the pressure was reduced. After reaching 220°C, it was set to 13.3 kPa in 90 minutes. The phenol vapor produced as a by-product along with the polymerization reaction is introduced into a reflux cooler at 100°C, and a certain amount of monomer components contained in the phenol vapor are returned to the reactor, and the uncondensed phenol vapor is introduced into a 45°C condenser for recovery . After introducing nitrogen gas into the first reactor to temporarily repress the pressure to atmospheric pressure, the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Next, the temperature rise and pressure reduction in the second reactor were started, and the internal temperature was 240° C. and the pressure was 0.2 kPa over 50 minutes. After that, polymerization is performed until a specific stirring power is reached. When the specific power is reached, nitrogen is introduced into the reactor for repressurization, the resulting polyester carbonate is extruded in water, and the strand is cut to obtain pellets. After the obtained polycarbonate resin was vacuum dried at 80°C for 5 hours, a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., barrel setting temperature: 250°C), T-die (width: 300 mm, Set temperature: 250°C), cooling roll (set temperature: 120～130°C) and film forming device of the winder to produce polycarbonate resin film with a thickness of 135 μm. The unstretched polycarbonate resin film is stretched using a stretching device to obtain a stretched resin film. The preheating temperature was set to 145°C and the extension temperature was set to 138°C. The extension magnification is set to 2.8 times. Re (550) of the resin film after the extension is 140 nm. A phase difference film was obtained by immersing one side of the extended resin film in a liquid in which methyl ethyl ketone and isopropyl alcohol were mixed at a mass ratio of 50:50 for 5 seconds (immersion treatment). The surface of the retardation film was observed with a scanning electron microscope, and as a result, a ridge shape was formed along the direction orthogonal to the extension axis. A polarizing plate with a retardation layer and a retardation film is laminated on the surface of the polarizing element side of the polarizing plate with an adhesive interposed therebetween.

[Example 2] A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Example 1, except that the immersion time in the liquid was set to 10 seconds.

[Example 3] A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Example 1, except that the immersion time in the above liquid was set to 15 seconds.

[Example 4] A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Example 1, except that the immersion time in the above liquid was set to 20 seconds.

[Example 5] A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Example 1, except that the immersion time in the above liquid was set to 25 seconds.

[Example 6] A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Example 1, except that the immersion time in the liquid was set to 30 seconds.

[Example 7] A phase difference film was obtained in the same manner as in Example 1, except that one side of the stretched resin film was immersed in a liquid obtained by mixing ethyl acetate and isopropyl alcohol at a mass ratio of 50:50 for 15 seconds. And polarizing plate with retardation layer.

[Example 8] A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Example 7 except that the immersion time in the above liquid was set to 20 seconds.

[Comparative Example 1] A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Example 1, except that the stretched resin film was not immersed in the liquid.

[Comparative Example 2] Except that one side of the extended resin film was immersed in a liquid obtained by mixing methyl ethyl ketone and isopropyl alcohol at a mass ratio of 60:40 for 120 seconds, the same procedure as in Example 1 was performed to obtain a retardation film and an additional film. Polarizing plate of phase difference layer.

[Comparative Example 3] Except that one side of the extended resin film was immersed in a liquid obtained by mixing methyl ethyl ketone and isopropyl alcohol at a mass ratio of 40:60 for 120 seconds, the same procedure as in Example 1 was performed to obtain a retardation film and an additional film. Polarizing plate of phase difference layer.

[Comparative Example 4] Relative to 81.98 parts by mass of isosorbide, 47.19 parts by mass of tricyclosilane dimethanol, 175.1 parts by mass of diphenyl carbonate, and 0.979 parts by mass of 0.2% by mass aqueous solution of cesium carbonate as a catalyst were put into the reaction vessel, stirring as needed Dissolve the raw material (about 15 minutes). Next, the pressure was changed from normal pressure to 13.3 kPa, and while the temperature of the heating tank was raised to 190°C over 1 hour, the produced phenol was drawn out of the reaction vessel. After the whole reaction vessel was kept at 190°C for 15 minutes, as the second step, the pressure in the reaction vessel was set to 6.67 kPa, the temperature of the heating tank was raised to 230°C in 15 minutes, and the generated phenol was extracted to the reaction Outside the container. Since the stirring torque of the stirrer increased, the temperature was raised to 250°C in 8 minutes. In order to further remove the generated phenol, the pressure in the reaction vessel was reduced to 0.200 kPa or less. After reaching a specific stirring torque, the reaction is ended, and the resulting reactant is extruded in water to obtain polycarbonate resin pellets. After the obtained polycarbonate resin was vacuum dried at 80°C for 5 hours, a single screw extruder (manufactured by Isuzu Kakoki Co., Ltd., screw diameter: 25 mm, barrel setting temperature: 220°C) was used , T-die (width: 200 mm, set temperature: 220 ℃), cooling roller (set temperature: 120 ~ 130 ℃) and film-making device of the winder to produce polycarbonate resin film with a thickness of 120 μm. A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Example 1, except that the polycarbonate resin film was used as the unstretched resin film and the stretched resin film was not immersed in the liquid.

[Comparative Example 5] Except that the resin film of Comparative Example 4 was used as the stretched resin film and the immersion time in the above liquid was set to 120 seconds, the same procedure as in Example 1 was performed to obtain polarized light with a retardation film and a retardation layer board.

[Comparative Example 6] A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Comparative Example 5 except that a liquid obtained by mixing methyl ethyl ketone and isopropyl alcohol at a mass ratio of 80:20 was used.

[Comparative Example 7] A retardation film and a polarizing plate with a retardation layer were obtained in the same manner as in Comparative Example 6 except that the immersion time in the above liquid was set to 300 seconds.

[Comparative Example 8] Use a norbornene-based resin film with a thickness of 65 μm (manufactured by JSR, product name "ARTON") as the unstretched resin film, and apply one side of the stretched resin film to cyclopentyl methyl ether and methyl Isobutyl ketone was immersed in a liquid mixed at a mass ratio of 50:50 for 120 seconds, and otherwise the same as in Example 1, a retardation film and a polarizing plate with a retardation layer were obtained.

The retardation films of Examples and Comparative Examples were used in the above evaluations (1) to (3). Only the polarizing plate with a retardation layer using the retardation film with good adhesion resistance of (3) was subjected to the above evaluations (4) to (5) as a secondary evaluation. In addition, regarding the above (4), for comparison, a polarizing plate with a retardation layer having a retardation film produced without immersion treatment was also produced, and evaluated in the same manner. The results are shown in Table 1.

[Table 1]

As shown in Table 1, the retardation films of Comparative Examples 1 to 6 and 8 have low blocking resistance, and the retardation film of Comparative Example 7 did not obtain sufficient brightness when used in an image display device. The retardation film of the embodiment is excellent in blocking resistance and obtains sufficient brightness when used in an image display device. Furthermore, it can be seen from the comparison between Examples 1 to 4 and Examples 5 to 6, that as the time of the immersion treatment becomes longer, the haze becomes higher, and as a result, the reflectance becomes higher. [Industry availability]

The retardation film of the embodiment of the present invention is suitable for an image display device.

Claims (10)

A phase difference film comprising a resin film subjected to extension treatment, and The arithmetic mean roughness Ra of at least one surface is above 2 nm, The haze value did not reach 2.6%. The retardation film of claim 1 has a ridge shape along a direction orthogonal to the extension axis. The retardation film of claim 1, wherein the resin film is a polycarbonate resin film. The retardation film of claim 1, wherein the above-mentioned stretching process is uniaxial stretching. A polarizing plate with a phase difference layer, comprising a polarizing plate and a phase difference layer, and The above-mentioned retardation layer includes the retardation film of claim 1. A method of manufacturing a retardation film, which is a method of manufacturing a retardation film as in claim 1, and It includes immersing the above-mentioned stretched resin film in a liquid containing good and poor solvents relative to the above-mentioned resin film. The manufacturing method according to claim 6, wherein the immersion time of the resin film in the liquid is 1 second to 110 seconds. The manufacturing method according to claim 6, wherein the resin film is a polycarbonate resin film, the good solvent is ethyl acetate or methyl ethyl ketone, and the bad solvent is isopropyl alcohol. The manufacturing method according to claim 6, wherein the mass ratio of the good solvent to the bad solvent in the liquid is 45:55 to 55:45. The manufacturing method according to claim 6, which further includes drying the above-mentioned impregnated resin film.