TW202006004A - Optical film, optical multilayer body and liquid crystal display device - Google Patents

Abstract

An optical film, which is an optical film made of thermoplastic resins and stretched films. The stress birefringence C _{R of the} thermoplastic resins is greater than 2900×10 ⁻¹² Pa ⁻¹ and the glass transition temperature Tg is 125° C. or higher, and the ratio of the retardation Rth in the thickness direction of the optical film to the thickness d (Rth/d) is 3.5×10 ⁻³ or more. An optical stack provided with the optical film and a liquid crystal display device provided with the optical stack are also provided.

Description

Optical film, optical stack and liquid crystal display device

The invention relates to an optical film, an optical stack and a liquid crystal display device.

Conventionally, an optical film made of a thermoplastic resin is known. For example, Patent Document 1 has disclosed an optical film including thermoplastic norbornene resin.

"Patent Literature" "Patent Document 1": Japanese Patent Publication No. 2003-238705 (corresponding bulletin: US Patent Application Publication No. 2004/057141 specification)

In the optical film used in the liquid crystal display device, there is a demand for an excellent retardation expressibility and a high retardation Rth in the thickness direction. As a method for obtaining an optical film with a high retardation Rth in the thickness direction using a film made of a conventional thermoplastic resin, it may be considered to stretch at a high stretch ratio. However, in the case where a film obtained by stretching at a high stretching ratio is joined to other parts, a phenomenon that the film is peeled off from other parts (peeling layer) may occur due to damage to a portion near the surface of the film.

The present invention was invented in view of the aforementioned problems, and its object is to provide an optical film excellent in phase difference visibility, high retardation in the thickness direction, and suppressing the occurrence of delamination, an optical stack including the optical film, and an optical stack including the optical stack The liquid crystal display device.

The inventor has made intensive studies to solve the aforementioned problems. As a result, the present inventors found: C _R by using large stress birefringence, high glass transition temperature Tg of the thermoplastic drop 𦯉-based resin as the material of the optical film, and the thickness retardation Rth of the optical film with respect to a direction of thickness d If the ratio (Rth/d) is made above the specified value, the aforementioned problems can be solved and the present invention can be completed.

That is, the present invention includes the following.

[1] An optical film, an optical film which is a thermoplastic resin obtained by reducing the olefinic 𦯉, and based stretched film, wherein the thermoplastic reducing stress birefringence 𦯉-based resin C _R of greater than 2900 × 10 ^-12 Pa ^-1 The glass transition temperature Tg is 125° C. or higher, and the ratio of the retardation Rth in the thickness direction of the optical film to the thickness d (Rth/d) is 3.5×10 ⁻³ or higher.

[2] The optical film as described in [1], whose retardation Re in the in-plane direction is 40 nm or more and 80 nm or less.

[3] The optical film as described in [1] or [2], where The aforementioned thermoplastic resins contain polymers, The aforementioned polymer includes a monomer unit having an aromatic ring structure.

[4] The optical film as described in [3], wherein the polymer includes the above-mentioned reduced-ene monomer unit having an aromatic ring structure of 25% by weight or more.

[5] An optical stack having: The optical film as described in any of [1] to [4], and A polarizing plate provided on the aforementioned optical film.

[6] A liquid crystal display device including the optical stack as described in [5].

According to the present invention, it is possible to provide an optical film excellent in phase difference visibility, high retardation in the thickness direction, and suppressing occurrence of delamination, an optical stack including the optical film, and a liquid crystal display device including the optical stack.

The embodiments and examples are disclosed below to explain the present invention in detail. However, the present invention is not limited to the embodiments and examples shown below, and can be implemented with any changes without departing from the scope of the patent application of the present invention and its equivalent scope.

In the following description, the in-plane retardation Re of the film is the value expressed by Re=(nx-ny)×d unless otherwise noted. In addition, the retardation Rth in the thickness direction of the film is a value expressed by Rth={[(nx+ny)/2]-nz}×d unless otherwise noted. Here, nx represents the refractive index which is the direction perpendicular to the thickness direction of the film (in-plane direction) and the direction giving the maximum refractive index. ny represents the refractive index in the direction of the aforementioned in-plane direction and perpendicular to the direction of nx. nz represents the refractive index in the thickness direction. d represents the thickness of the film. Unless otherwise noted, the measurement wavelength is 550 nm.

In the following description, the direction of the constituent elements is "parallel", "vertical" or "orthogonal", and unless specifically noted, it may be included in the range of, for example, generally ±5 within the range that does not impair the effects of the present invention. °──±2° is better, ±1° is better─the error within the range.

In the following description, the MD direction (machine direction) is the flow direction of the film in the production line, and the TD direction (traverse direction) is the direction parallel to the film surface and the direction perpendicular to the MD direction. In addition, in terms of cheapness, the longitudinal direction of the long film is sometimes referred to as the MD direction of the film, and the width direction as the TD direction of the film.

In the following description, the so-called "strip-shaped" film refers to a film that has a length of 5 times or more relative to the width of the film, preferably 10 times or more, and specifically refers to having a rollable The length of the roller to the extent of storage or transportation. The upper limit of the ratio of the film to the length of the width is not particularly limited, but it may be set to, for example, 100,000 times or less.

In the following description, unless otherwise noted, the so-called "polarizer" includes not only rigid components but also flexible components such as resin films.

[1. Optical film]

The optical film of the present invention is a film made of thermoplastic resin. The optical film is an extended film obtained by extending a film that becomes a material of the optical film. In the following description, the film that becomes the material of the optical film is also referred to as a "pre-stretch film."

(Thermoplastic resin)

Thermoplastic vinylene resins contain polymers. Examples of the polymer included in the thermoplastic norene-based resin include, for example, ring-opening polymers having a monomer having a norene structure, or ring-opening copolymers of monomers having a norene structure and other monomers, Or these hydrides; addition polymers of monomers with a reduced ene structure, or addition copolymers of monomers with a reduced ene structure and other monomers, or these hydrides, etc.

As the monomer having a reduced ene structure, bicyclo[2.2.1]hept-2-ene (common name: reduced ene), tricyclo[4.3.0.1 ^2,5 ]dec-3,7-diene (common name: dicyclopentadiene, also referred to as "DCPD"), tetracyclo [4.4.0.1 ^2,5 .1 ^7,10] twelve-3-ene (common name: tetracyclododecene, also referred to as "TCD"), and derivatives of these compounds (for example, those with substituents in the ring). Here, as a substituent, an alkyl group, an alkylene group, a polar group, etc. are mentioned, for example. In addition, these substituents may be the same or different from each other, and a plurality of ring bonds may be used. The monomer with a reduced ene structure can be used alone or in combination of two or more.

Examples of the type of polar group include heteroatoms and atomic groups having heteroatoms. Examples of heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, silicon atoms, halogen atoms, and the like. Specific examples of the polar group include a carboxyl group, a carbonyloxycarbonyl group, an epoxy group, a hydroxyl group, an oxy group, an ester group, a silanol group, a silyl group, an amine group, a nitrile group, and a sulfonyl group. In order to obtain a thin film with a low saturated water absorption rate, it is better to have a small amount of polar groups, and it is better to have no polar groups.

As a monomer having a reduced ene structure, from the viewpoint of excellent phase difference manifestation, it is necessary to use a reduced ene monomer having an aromatic ring structure instead of or in addition to the above monomer with a reduced ene structure Use monomers of olefin structure together.

Examples of the norbornene monomer having an aromatic ring structure include 5-phenyl-2-norbornene, 5-(4-methylphenyl)-2-norbornene, and 5-(1-naphthalene Group) 2-northene, 9-(2-northene-5-yl)carbazole and other aromatic substituents; 1,4-methyl bridge-1,4,4a ,4b,5,8,8a,9a-octahydrostilbene, 1,4-methylqiao-1,4,4a,9a-tetrahydrostilbene (common name: methylqiao tetrahydrostilbene, hereinafter also referred to as "MTF") , 1,4-methyl bridge-1,4,4a,9a-tetrahydrodibenzofuran, 1,4-methyl bridge-1,4,4a,9a-tetrahydrocarbazole, 1,4-methyl bridge- 1,4,4a,9,9a,10-hexahydroanthracene, 1,4-methyl bridge-1,4,4a,9,10,10a-hexahydrophenanthrene is equivalent to a fused polycyclic structure with a reduced ene ring Reduction of structure and aromatic ring structure ene monomers; etc. These monomers can be used alone or in combination of two or more.

The vinyl monomer having an aromatic ring structure may also have a substituent. Examples of the substituent include alkyl groups such as methyl, ethyl, propyl, and isopropyl; alkylene groups; alkenyl groups; halogen groups such as fluoro, chloro, bromo, and iodo groups; hydroxyl groups; and ester groups; Alkoxy group; cyano group; amide group; amide imine group; silyl group; etc. The vinyl monomer having an aromatic ring structure may also have two or more of these substituents.

Examples of other monomers capable of ring-opening copolymerization with monomers having a reduced ene structure include: cyclohexene, cycloheptene, cyclooctene and other monocyclic olefins and their derivatives; cyclohexadiene, cyclic Cyclic conjugated diene and its derivatives such as heptadiene; etc.

The ring-opening polymer with a monomer with a reduced ene structure and the ring-opening copolymer with a monomer with a reduced ene structure and other monomers that can be copolymerized can be obtained by using the monomer in a well-known ring-opening polymerization catalyst It is obtained by (co)polymerization in the presence of.

Examples of other monomers capable of addition copolymerization with monomers having a reduced ene structure include, for example, ethylene, propylene, 1-butene, and the like having 2 to 20 carbon atoms and their derivatives; rings Cyclic olefins such as butene, cyclopentene, cyclohexene and their derivatives; 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4- Hexadiene and other non-conjugated dienes. These monomers can be used alone or in combination of two or more. Among these, α-olefin is preferred, and ethylene is preferred.

Addition polymers of monomers with a reduced ene structure and addition copolymers of monomers with a reduced ene structure and other monomers that can be copolymerized can be obtained by adding monomers to well-known addition polymerization catalysts It is obtained by polymerization in the presence of.

Hydrides of ring-opening polymers of monomers with reduced ene structure, hydrides of ring-opening copolymers of monomers with reduced ene structure and other monomers capable of ring-opening copolymerization, with pentene Hydrides of addition polymers of structural monomers and addition copolymers of monomers with a reduced ene structure and other monomers capable of addition copolymerization can be opened by these rings The (co)polymer or addition (co)polymer solution is obtained by adding a well-known hydrogenation catalyst containing transition metals such as nickel and palladium to contact it with hydrogen to hydrogenate the carbon-carbon unsaturated bond.

In the present invention, the polymer is a ring-opening (co)polymer which is a non-aromatic unsaturated bond through selective hydrogenation and contains a drop having an aromatic ring structure from the viewpoint of excellent retardation development 𦯉 Those with monomeric monomers are preferred. Here, the "monomer unit" refers to a structural unit having a structure formed by polymerizing its monomer.

A polymer containing a monomeric unit having a reduced aromatic ring structure can be obtained by adding a ruthenium catalyst to the solution of the above ring-opening (co)polymer or addition (co)polymer and contacting it with hydrogen. Examples of ruthenium catalysts include: [1,3-bis(2,4,6-trimethylphenyl)imidazolidine-2-ylidene](tricyclohexylphosphine)benzylidene ruthenium dichloride, hydrochloride Carbonyl ginseng (triphenylphosphine) ruthenium, bis(tricyclohexylphosphine) dichloride benzylidene ruthenium (IV), ginseng dichloride (triphenylphosphine) ruthenium, carbonyl ginseng dichloride (triphenylphosphine )ruthenium. By analyzing the result of this hydrogenation using ¹ H-NMR, the presence or absence of the carbon-carbon double bond in the main chain structure can be distinguished from the unsaturated bond in the aromatic ring structure for analysis. Therefore, by this ¹ H-NMR analysis, it can be confirmed whether the non-aromatic unsaturated bond has been selectively hydrogenated.

In the case where the polymer contains a reduced olefinic monomer unit having an aromatic ring structure, the amount of the reduced olefinic monomer unit having an aromatic ring structure in the polymer is preferably 25% by weight or more and 40% by weight or more Preferably, it is preferably 80% by weight or less, preferably 60% by weight or less. If the amount of vinyl monomer units in the polymer having an aromatic ring structure is above the lower limit, the stress birefringence C _R can be increased, the stretching ratio when the film before stretching can be stretched can be suppressed, and the optical film can be increased at the same time. Rth.

The molecular weight of the polymer included in the thermoplastic resin can be appropriately selected according to the purpose of the optical film, but the gel permeation layer through the use of cyclohexane (toluene when the resin is not dissolved) as the solvent The weight average molecular weight (Mw) in terms of polyisoprene (polystyrene when the solvent is toluene) measured by analysis method is preferably 10,000 to 100,000, preferably 15,000 to 80,000, preferably 20,000 to 60,000 Is particularly good. When the weight average molecular weight is in this range, the mechanical strength and formability of the film are highly balanced, which is suitable.

The molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) of the polymer contained in the thermoplastic reduced vinyl resin is not particularly limited, but it is usually 1.0 to 10.0-preferably 1.0 to 5.0. 1.0 to 3.5 is the preferred range.

Thermoplastic vinylene resins may contain any components other than polymers. Examples of optional components include ultraviolet absorbers, antioxidants, heat stabilizers, light stabilizers, antistatic agents, dispersants, chlorine scavengers, flame retardants, crystal nucleating agents, strengthening agents, anti-caking agents, Anti-fogging agent, release agent, pigment, organic or inorganic filler, neutralizer, slip agent, decomposition agent, metal deactivator, antifouling agent and antibacterial agent.

Examples of the ultraviolet absorber include oxybenzophenone-based compounds, benzotriazole-based compounds, salicylate-based compounds, benzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, Acrylonitrile-based ultraviolet absorbers, tri-based compounds, nickel-coated salt-based compounds and inorganic powders. Examples of suitable ultraviolet absorbers include: 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-2 -Yl)phenol], 2-(2'-hydroxy-3'-tertiary butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2,4-di(tertiary butyl) -6-(5-chlorobenzotriazol-2-yl)phenol, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'- Tetrahydroxybenzophenone. Examples of particularly suitable ones include: 2,2'-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazol-2-yl )phenol].

In the case where the thermoplastic reduced ene resin contains an ultraviolet absorber, the content of the ultraviolet absorber is preferably 0.5 to 5% by weight per 100% by weight of the thermoplastic reduced ene resin.

(Thermoplastic lowers the physical properties of vinyl resins)

In the present invention, the thermoplastic resin lowering stress birefringence olefinic C _R 𦯉 than 2900 × 10 ^-12 Pa ^-1 larger. The stress birefringence C _{R of the} thermoplastic reduced vinyl resin is preferably 2910×10 ⁻¹² Pa ⁻¹ or more, preferably 3000×10 ⁻¹² Pa ⁻¹ or more, and 8000×10 ⁻¹² Pa ⁻¹ or less Preferably, 6000×10 ⁻¹² Pa ⁻¹ or less is preferable. By reducing the stress birefringence C _{R of} the thermoplastic resin, which is greater than 2900×10 ⁻¹² Pa ⁻¹ , the stretching magnification of the film before stretching can be suppressed, and the Rth of the optical film can be increased at the same time. By lowering the stress of the thermoplastic resin 𦯉 olefinic C _R birefringent made the upper limit, it can be easily controlled Re and Rth of the film, in-plane mixed inhibition.

C _R stress birefringence can be reduced by changing the ratio 𦯉 used for producing a thermoplastic polymer resin comprising the time-based monomer to the control. For example, if increased drop having a proportion of aromatic ring structure-based monomer 𦯉 above, have increased the stress birefringence C _R.

C _R stress birefringence obtained by, for example, the following method of measurement.

The thermoplastic norbornene-based resin is formed into a sheet shape to prepare a sample. After fixing both ends of the sample with a jig, a weight of a specified weight (for example, 160 g) is fixed to one of the jigs. Then, in an oven set to a specified temperature (eg, resin glass transition temperature (Tg) + 5°C), fix the unfixed weight clamp as a supporting point, and hang the sheet for a specified time (eg, 1 hour) for extension treatment . The sample sheet that has undergone the extension treatment is slowly cooled back to room temperature, and used as a quantity test sample. For this amount of test sample, the birefringence measurement was used to measure the retardation value (a nm) at the center of the test sample and the thickness (b mm) at the center of the test sample. Using the measured values (a, b), the δn value was calculated by the following formula (1). δn=a×(1/b)×10 ⁻⁶ (1)

Using this δn value and the stress applied to the sample (in the above case, the stress applied when the specified weight is fixed), C _R can be calculated by the following formula (2). C _R = δn/stress (2)

The glass transition temperature Tg of the thermoplastic reduced ene resin is above 125°C. The glass transition temperature Tg is preferably 130°C or higher, preferably 135°C or higher, and preferably 180°C or lower, and preferably 160°C or lower. By setting the glass transition temperature Tg to 125°C or higher, it is possible to obtain an optical film with excellent heat resistance and durability. Tg must be measured using a differential scanning calorimeter.

(Film before stretching)

The pre-stretch film that becomes the material of the optical film is a film made of the above-mentioned thermoplastic resin.

The pre-stretch film can be manufactured by forming the thermoplastic reduced vinyl resin through a well-known method such as casting molding method, extrusion molding method, inflation molding method, etc. into a film shape.

(Optical film)

The optical film can be obtained by stretching the film before stretching. The stretching conditions when the film before stretching is made into an optical film are appropriately selected to obtain desired optical characteristics. For example, the stretching state when the film before stretching is made into an optical film may be any state such as uniaxial stretching and biaxial stretching (simultaneous biaxial stretching and successive biaxial stretching). In these aspects, biaxial extension is preferred. In addition, in the case where the film before stretching is an elongated film, the extending direction is longitudinal (direction parallel to the longitudinal direction of the elongated film), lateral (direction parallel to the width direction of the elongated film), and Either oblique (neither vertical nor horizontal) can be used.

When the pre-stretch film is stretched to make an optical film, the stretching magnification is preferably 1.4 or more, preferably 1.5 or more, and preferably 2.2 or less, and preferably 2.1 or less. If the stretching ratio is made equal to or lower than the upper limit of the aforementioned range, the occurrence of delamination can be more effectively suppressed, and if the stretching ratio is made equal to or higher than the lower limit of the aforementioned range, Rth can be increased. When the film before stretching is stretched by biaxial stretching in the MD direction and the TD direction, the product of the stretching magnification in the MD direction and the stretching magnification in the TD direction is preferably within the above range.

When stretching the film before stretching to make an optical film, the stretching temperature is preferably Tg°C or higher, preferably (Tg+5)°C or higher, and on the other hand, (Tg+40)°C or lower, preferably (Tg+30)°C or lower Better. By extending the temperature within the aforementioned range, an optical film with a uniform film thickness can be obtained.

(Physical value of optical film)

The thickness d of the optical film is preferably 30 μm or more, preferably 40 μm or more, and preferably 150 μm or less, and preferably 100 μm or less. By making the thickness of the optical film above the lower limit, the occurrence of delamination can be effectively suppressed, and by making the thickness of the optical film below the upper limit, the device incorporating the optical film can be made thinner.

In the present invention, the ratio of the retardation Rth in the thickness direction of the optical film to the thickness d (Rth/d) is 3.5×10 ⁻³ or more. Rth/d is preferably 3.5×10 ⁻³ or more, preferably 4.0×10 ⁻³ or more, and preferably 8.0×10 ⁻³ or less, and preferably 6.0×10 ⁻³ or less. By making Rth/d 3.5×10 ⁻³ or more, an optical film with a high Rth and a small thickness can be made, thereby obtaining a film with excellent optical compensation. By making Rth/d below the upper limit, the occurrence of delamination can be more effectively suppressed.

The retardation Re in the in-plane direction of the optical film is preferably 40 nm or more, preferably 50 nm or more, and preferably 80 nm or less, and preferably 70 nm or less. By making Re above the lower limit value, the phase difference visibility can be optimized, and by making Re below the upper limit value, in-plane variations can be suppressed. The delay Re is appropriately selected within the above range to suit the design of the display device.

(Optical stack)

The optical stack of the present invention includes the optical film of the present invention and a polarizing plate provided thereon.

As the polarizing plate, a polarizer made of a dichroic substance-containing polyvinyl alcohol-based polarizing film or the like can be used on one side or both sides of the polarizer, for example, a film (protective film) that is a protective layer is bonded through an intermediary bonding layer .

As the polarizer (polarizing film), for example, a film made of a vinyl alcohol-based polymer such as polyvinyl alcohol or partially formalized polyvinyl alcohol may be applied to transmit a dichroic substance such as iodine or a dichroic dye. Dyeing treatment, extension treatment, cross-linking treatment, etc. As the polarizer, those who pass through the linear polarizer when natural light is incident must be used.

As a protective film material to be a transparent protective layer provided on one side or both sides of a polarizer (polarizing film), a transparent film can be used. As the transparent film, a film made of a resin excellent in transparency, mechanical strength, thermal stability, moisture shielding properties, etc. is preferably used. Examples of such resins include acetate-based resins or polyester-based resins such as cellulose triacetate, polyether-based resins, polycarbonate-based resins, polyamide-based resins, and polyimide-based resins. Resins, polyolefin resins, norbornene resins, acrylic resins, etc. From the viewpoint of low birefringence, it is preferable to use an acetate-based resin or a vinylene-based resin, and from the viewpoint of transparency, low moisture absorption, dimensional stability, and lightness, etc., to use a vinylene-based resin Resin is particularly preferred.

Although the thickness of the protective film is arbitrary, it is generally 500 μm or less for the purpose of thinning the polarizing plate, etc., preferably 5 to 300 μm, particularly preferably 5 to 150 μm.

The stacking of the optical film and the polarizing plate can be carried out by interposing these layers through the intermediary. Examples of such a layered body include a layered body of an adhesive and a layered body of an adhesive. Examples of the bonding agent or adhesive include acrylic, polysiloxane, polyester, polyurethane, polyether, and rubber. Among these, from the viewpoint of heat resistance, transparency, and the like, those based on acrylic are preferred.

In the optical stack of the present invention, the optical film of the present invention can also be used as a protective film for stacked polarizing plates, and the components can be thinned. In addition, the stacking of the optical film and the polarizing plate can be performed by roller-to-roller, and an elongated optical stack can be obtained. The angle between the slow axis of the optical film in the optical stack and the absorption axis of the polarizing plate must be within 90°±1°.

The thickness of the optical stack of the present invention is preferably 30 μm or more, preferably 40 μm or more, and preferably 150 μm or less, and preferably 100 μm or less.

[Liquid Crystal Display Device]

The liquid crystal display device of the present invention includes the optical stack of the present invention. The liquid crystal display device of the present invention includes the optical stack of the present invention on at least one side of the liquid crystal cell.

In the liquid crystal display device, the optical film is usually disposed between the liquid crystal cell of the liquid crystal display device and the viewing side polarizer. In such a structure, the optical film can function as a viewing angle compensation film.

The liquid crystal cell may use, for example, in-plane switching (IPS) mode, vertical arrangement (VA) mode, multi-region vertical arrangement (MVA) mode, continuous firework arrangement (CPA) mode, mixed arrangement nematic (HAN) mode, twisted nematic (TN) mode, Super Twisted Nematic (STN) mode, Optical Compensation Bending (OCB) mode and other arbitrary modes of liquid crystal cells.

When polarizing plates are provided on both sides of the liquid crystal cell, the polarizing plates may be the same or different.

In the liquid crystal display device of the present invention, in order to join the optical stack of the present invention to the liquid crystal cell, an adhesive layer must be provided. The adhesive layer can be appropriately formed using a conventionally known adhesive such as acrylic. Among them, the prevention of the foaming phenomenon or peeling phenomenon caused by moisture absorption, the prevention of the degradation of optical characteristics caused by the difference in thermal expansion, the warpage of the liquid crystal cell, and even the formation of high-quality and excellent durability liquid crystal display devices In terms of properties, the adhesive layer with a low moisture absorption rate and excellent heat resistance is preferred. In addition, it must be made into an adhesive layer containing fine particles and exhibiting light diffusibility.

『Examples』

The following examples are disclosed to specifically illustrate the present invention. However, the present invention is not limited to the following embodiments, and can be implemented with any changes without departing from the scope of the patent application of the present invention and its equivalent scope.

In the following description, the "%" and "parts" indicating the amount are based on weight unless otherwise noted. Unless otherwise noted, the following operations are performed in normal temperature and pressure atmosphere.

[Measurement methods and calculation methods of physical properties of polymers]

(Measurement of weight average molecular weight (Mw), number average molecular weight (Mn) and molecular weight distribution (Mw/Mn))

The weight average molecular weight (Mw) and number average molecular weight (Mn) of polymers (ring-opening polymers and polymers (1) to (3), polymers (C1) to (C5)) are determined by cyclohexane It was measured by gel permeation chromatography (GPC) as the eluate, and the converted value of standard polyisoprene was obtained.

As the standard polyisoprene, standard polyisoprene (Mw=602, 1390, 3920, 8050, 13800, 22700, 58800, 71300, 109000, 280000) manufactured by Tosoh Corporation was used.

The measurement system used three columns (TSKgel G5000HXL, TSKgel G4000HXL, and TSKgel G2000HXL) made by Tosoh Corporation in series under the conditions of a flow rate of 1.0 mL/min, a sample injection volume of 100 μL, and a column temperature of 40°C.

The molecular weight distribution (Mw/Mn) is calculated using the measured value measured by the above method.

(Measurement of glass transition temperature (Tg))

The glass transition temperature (Tg) of the polymers (1) to (3) and the polymers (C1) to (C5) is a differential scanning calorimeter (manufactured by SII NanoTechnology Inc., product name: DSC6220), based on JIS K 6911, measured at a temperature increase rate of 10°C/min.

(Measurement of stress birefringence C _R)

The polymers (1) to (3) and the polymers (C1) to (C5) were formed into 35 mm×10 mm×1 mm sheets to prepare samples. After fixing both ends of this sample with a jig, fix a 160 g weight to one of the jigs. Then, in an oven where the temperature is set to the glass transition temperature (Tg) of the polymer + 5°C, fix the fixture without the weight as the support point, suspend the sheet for 1 hour for extension treatment, and slowly cool back to At room temperature, use it as a test sample.

For the aforementioned quantity test sample, use a birefringence meter (manufactured by Photonic Lattice, Inc., WPA-100) to measure the retardation value of the central portion of the quantity test sample in the light of wavelength 650 nm (this measurement value is defined as a nm.). And, measure the thickness of the center of the test sample (this measurement value is set to b mm.).

Using the measured values a and b, the δn value was calculated by the following formula (1). δn=a×(1/b)×10 ⁻⁶ (1)

Using this value δn and the stress imposed on the sample, by the following formula (2) calculated C _R. C _R = δn/stress (2)

(Confirm the presence or absence of aromatic rings in the hydrogenation of norbornene ring-opening copolymers)

The polymer before hydrogenation and the hydrogenated polymer were analyzed by ¹ H-NMR. In the analysis, deuterated chloroform was used as the solvent system. From the results of the analysis, the hydrogenation rate of the non-aromatic unsaturated bond and the hydrogenation rate of the aromatic unsaturated bond are determined. From these results, the presence or absence of aromatic rings in the hydrogenation of the ring-opening copolymer of norbornene series was confirmed.

[Production Example 1: Production of polymer (1)]

(1-1) Manufacture of ring-opening polymers

In a glass reaction vessel replaced with nitrogen inside, add [1,3-bis(2,4,6-trimethylphenyl)imidazolidine-2-ylidene](tricyclohexyl) which is a polymerization catalyst Phosphine) benzylene ruthenium 0.05 parts by weight, toluene 500 parts by weight, 1,4-methyl bridge-1,4,4a,9a-tetrahydrostilbene (MTF) 50 parts by weight as a monomer, tetracyclododecene ( TCD) 20 parts by weight, 30 parts by weight of dicyclopentadiene (DCPD) and 0.75 parts by weight of 1-hexene as a chain transfer agent, and the whole was stirred at 60°C for 2 hours and stirred for ring-opening polymerization. The Mw of the obtained ring-opening polymer was 3.3×10 ⁴ and the molecular weight distribution (Mw/Mn) was 2.3. Moreover, the conversion rate from monomer to polymer was 100%.

(1-2) Manufacture of polymer (1)

Subsequently, 300 parts of the reaction solution containing the ring-opening polymer obtained in (1-1) was transferred to an autoclave with a stirrer, and carbonyl ginseng (triphenylphosphine) ruthenium hydrochloride (hereinafter abbreviated as " "Ruthenium catalyst".) 0.0043 parts, hydrogenation reaction at a hydrogen pressure of 4.5 MPa and 160°C for 4 hours.

After the hydrogenation reaction is completed, the obtained solution is poured into a large amount of isopropyl alcohol to precipitate a polymer (hydride). After filtering out the obtained polymer, it was dried with a vacuum dryer (220° C., 1 Torr) for 6 hours to obtain polymer (1). The Mw of the polymer (1) was 4.3×10 ⁴ and the Mw/Mn was 2.5. And, Tg of the polymer (1) was 128 ℃, C _R is 3900 × 10 ^-12 Pa ^-1.

As a result of ¹ H-NMR analysis of the obtained polymer, it was confirmed that in the polymer (1), the non-aromatic unsaturated bond was selectively hydrogenated, and on the other hand, the aromatic unsaturated bond remained .

[Production Example 2: Production of polymer (2)]

(2-1) Manufacture of ring-opening polymers

Except that the addition amount of the monomers (MTF, TCD, and DCPD) in Production Example 1 (1-1) was 40 parts by weight of MTF, 35 parts by weight of TCD, and 25 parts by weight of DCPD, the same procedure as in Production Example 1 ( 1-1) In the same operation, a ring-opening polymer is obtained. The Mw of the ring-opening polymer is 3.1×10 ⁴ and the molecular weight distribution is 2.2. The conversion rate from monomer to polymer is 100%.

(2-2) Manufacturing of polymer (2)

Except for using 300 parts of the reaction solution containing the ring-opening polymer obtained in (2-1) in (1-2) of Production Example 1 instead of 300 parts of the reaction solution containing the ring-opening polymer obtained in (1-1) Other than that, the same operation as (1-2) was performed to obtain polymer (2). The Mw of the polymer (2) was 4.0×10 ⁴ and the Mw/Mn was 2.4. The Tg of the polymer (2) is 136°C and the _CR is 3200×10 ⁻¹² Pa ⁻¹ .

As a result of ¹ H-NMR analysis of the obtained polymer, it was confirmed that in the polymer (2), the non-aromatic unsaturated bond was selectively hydrogenated, and on the other hand, the aromatic unsaturated bond remained .

[Production Example 3: Production of polymer (3)]

(3-1) Manufacture of ring-opening polymers

Except that the amount of monomers (MTF, TCD, and DCPD) added in (1-1) of Production Example 1 was 25 parts by weight of MTF, 35 parts by weight of TCD, and 40 parts by weight of DCPD, the same procedure as in Production Example 1 ( 1-1) In the same operation, a ring-opening polymer is obtained. The Mw of the ring-opening polymer is 3.2×10 ⁴ and the molecular weight distribution is 2.4. The conversion rate from monomer to polymer is 100%.

(3-2) Manufacture of polymer (3)

Except for using 300 parts of the reaction solution containing the ring-opening polymer obtained in (3-1) in (1-2) of Production Example 1 instead of 300 parts of the reaction solution containing the ring-opening polymer obtained in (1-1) Otherwise, the same operation as (1-2) was performed to obtain polymer (3). The Mw of the polymer (3) was 4.2×10 ⁴ and the Mw/Mn was 2.6. Polymer (3) has a Tg of 128°C and a _CR of 3000×10 ⁻¹² Pa ⁻¹ .

As a result of ¹ H-NMR analysis of the obtained polymer, it was confirmed that in the polymer (3), the non-aromatic unsaturated bond was selectively hydrogenated, and on the other hand, the aromatic unsaturated bond remained .

[Production Example 4: Production of polymer (C1)]

(4-1) Manufacture of ring-opening polymers

Except that the addition amount of the monomers (MTF, TCD, and DCPD) in Production Example 1 (1-1) was set to 22 parts by weight of MTF, 38 parts by weight of TCD, and 40 parts by weight of DCPD, the same operation was performed to obtain Ring polymer. The Mw of the ring-opening polymer is 3.2×10 ⁴ and the molecular weight distribution is 2.3. The conversion rate from monomer to polymer is 100%.

(4-2) Manufacture of polymer (C1)

Except for using 300 parts of the reaction solution containing the ring-opening polymer obtained in (4-1) in (1-2) of Production Example 1 instead of 300 parts of the reaction solution containing the ring-opening polymer obtained in (1-1) Other than that, the same operation as (1-2) was performed to obtain polymer (C1). The Mw of the polymer (C1) was 4.1×10 ⁴ and the Mw/Mn was 2.5. The Tg of the polymer (C1) is 129°C, and the C _R is 2850×10 ⁻¹² Pa ⁻¹ .

As a result of ¹ H-NMR analysis of the obtained polymer, it was confirmed that in the polymer (C1), the non-aromatic unsaturated bond was selectively hydrogenated, and on the other hand, the aromatic unsaturated bond remained .

[Production Example 5: Production of polymer (C2)]

(5-1) Manufacture of ring-opening polymers

Except that the amount of monomers (MTF, TCD, and DCPD) added in (1-1) of Production Example 1 was 25 parts by weight of MTF, 35 parts by weight of TCD, and 40 parts by weight of DCPD, the same procedure as in Production Example 1 ( 1-1) In the same operation, a ring-opening polymer is obtained. The Mw of the ring-opening polymer is 3.2×10 ⁴ and the molecular weight distribution is 2.4. The conversion rate from monomer to polymer is 100%.

(5-2) Manufacture of polymer (C2)

Subsequently, 300 parts of the reaction solution containing the ring-opening polymer obtained in (5-1) was transferred to an autoclave equipped with a stirrer, and a diatomite-bearing nickel catalyst (manufactured by Nisshin Chemical Co., Ltd., product name "T8400RL") was added. , Nickel bearing rate 57%) 3 parts, hydrogenation reaction under hydrogen pressure 4.5 MPa, 160 ℃ for 4 hours.

After the hydrogenation reaction was completed, the obtained solution was pressure-filtered using a RADIOLITE #500 as a filter bed at a pressure of 0.25 MPa (manufactured by Ishikawashima Haruma Heavy Industries Co., Ltd., product name "FUNDABAC filter"), the hydrogenation catalyst was removed, and a colorless and transparent solution was obtained . The obtained solution was poured into a large amount of isopropyl alcohol to precipitate the polymer. After filtering off the obtained polymer, it was dried with a vacuum dryer (220° C., 1 Torr) for 6 hours to obtain a polymer (C2). The Mw of the polymer (C2) was 4.3×10 ⁴ and the Mw/Mn was 2.6. The Tg of the polymer (C2) is 136°C, and the C _R is 1900×10 ⁻¹² Pa ⁻¹ .

As a result of ¹ H-NMR analysis of the obtained polymer, it was confirmed that both the non-aromatic unsaturated bond and the aromatic unsaturated bond were hydrogenated in the polymer (C2).

[Production Example 6: Production of polymer (C3)]

(6-1) Manufacture of ring-opening polymers

Except that the addition amount of the monomers (MTF, TCD, and DCPD) in Production Example 1 (1-1) was 10 parts by weight of MTF, 40 parts by weight of TCD, and 50 parts by weight of DCPD, the same procedure as in Production Example 1 ( 1-1) In the same operation, a ring-opening polymer is obtained. The Mw of the ring-opening polymer is 3.2×10 ⁴ and the molecular weight distribution is 2.3. The conversion rate from monomer to polymer is 100%.

(6-2) Manufacture of polymer (C3)

Subsequently, 300 parts of the reaction solution containing the ring-opening polymer obtained in (6-1) was transferred to an autoclave equipped with a stirrer, and a diatomite-bearing nickel catalyst (manufactured by Nisshin Chemical Co., Ltd., product name "T8400RL") was added. , Nickel bearing rate 57%) 3 parts, hydrogenation reaction under hydrogen pressure 4.5 MPa, 160 ℃ for 4 hours.

After the hydrogenation reaction was completed, the obtained solution was pressure-filtered using a RADIOLITE #500 as a filter bed at a pressure of 0.25 MPa (manufactured by Ishikawashima Haruma Heavy Industries Co., Ltd., product name "FUNDABAC filter"), the hydrogenation catalyst was removed, and a colorless and transparent solution was obtained . The obtained solution was poured into a large amount of isopropyl alcohol to precipitate the polymer. After filtering out the obtained polymer, it was dried with a vacuum dryer (220° C., 1 Torr) for 6 hours to obtain a polymer (C3). The Mw of the polymer (C3) was 4.1×10 ⁴ and the Mw/Mn was 2.5. The Tg of the polymer (C3) is 128°C, and the C _R is 2200×10 ⁻¹² Pa ⁻¹ .

As a result of ¹ H-NMR analysis of the obtained polymer, it was confirmed that both the non-aromatic unsaturated bond and the aromatic unsaturated bond were hydrogenated in the polymer (C3).

[Production Example 7: Production of polymer (C4)]

(7-1) Manufacture of ring-opening polymers

Except that the amount of monomers (MTF, TCD, and DCPD) added in (1-1) of Production Example 1 was 5 parts by weight of MTF, 5 parts by weight of TCD, and 90 parts by weight of DCPD, the same procedure as in Production Example 1 ( 1-1) In the same operation, a ring-opening polymer is obtained. The Mw of the ring-opening polymer is 3.3×10 ⁴ and the molecular weight distribution is 2.3. The conversion rate from monomer to polymer is 100%.

(7-2) Manufacture of polymer (C4)

Subsequently, 300 parts of the reaction solution containing the ring-opening polymer obtained in (7-1) was transferred to an autoclave equipped with a stirrer, and a diatomite-bearing nickel catalyst (manufactured by Nisshin Chemical Co., Ltd., product name "T8400RL") was added. , Nickel bearing rate 57%) 3 parts, hydrogenation reaction under hydrogen pressure 4.5 MPa, 160 ℃ for 4 hours.

After the hydrogenation reaction was completed, the obtained solution was pressure-filtered using a RADIOLITE #500 as a filter bed at a pressure of 0.25 MPa (manufactured by Ishikawashima Haruma Heavy Industries Co., Ltd., product name "FUNDABAC filter"), the hydrogenation catalyst was removed, and a colorless and transparent solution was obtained . The obtained solution was poured into a large amount of isopropyl alcohol to precipitate the polymer. After filtering off the obtained polymer, it was dried with a vacuum dryer (220° C., 1 Torr) for 6 hours to obtain a polymer (C4). The Mw of the polymer (C4) was 3.9×10 ⁴ and the Mw/Mn was 2.7. The Tg of the polymer (C4) is 102°C and the _CR is 3100×10 ⁻¹² Pa ⁻¹ .

As a result of ¹ H-NMR analysis of the obtained polymer, it was confirmed that both the non-aromatic unsaturated bond and the aromatic unsaturated bond were hydrogenated in the polymer (C4).

[Production Example 8: Production of polymer (C5)]

(8-1) Manufacture of ring-opening polymers

In addition to using 50 parts by weight of TCD and 50 parts by weight of 8-methyltetracyclododecene (hereinafter sometimes referred to as MTD) in (1-1) of Production Example 1, instead of MTF, TCD, and DCPD as monomers, The same operation as (1-1) of Production Example 1 was performed to obtain a ring-opening polymer. The Mw of the ring-opening polymer is 4.0×10 ⁴ and the molecular weight distribution is 2.0. The conversion rate from monomer to polymer is 100%.

(8-2) Manufacture of polymer (C5)

Subsequently, 300 parts of the polymerization reaction solution obtained in (8-1) was transferred to an autoclave equipped with a stirrer, and a diatomite-bearing nickel catalyst (manufactured by Nisshin Chemical Co., Ltd., product name "T8400RL", nickel bearing rate 57) was added %) 3 parts, hydrogenation reaction at a hydrogen pressure of 4.5 MPa and 160°C for 4 hours.

After the hydrogenation reaction was completed, the obtained solution was pressure-filtered using a RADIOLITE #500 as a filter bed at a pressure of 0.25 MPa (manufactured by Ishikawajima Harumi Heavy Industries Co., Ltd., product name "FUNDABAC filter") to remove the hydrogenation catalyst and obtain a colorless and transparent solution . The obtained solution was poured into a large amount of isopropyl alcohol to precipitate the polymer. After filtering out the obtained polymer, it was dried with a vacuum dryer (220° C., 1 Torr) for 6 hours to obtain a polymer. The Tg of this polymer was 158°C.

28 parts by weight of this polymer, 10 parts by weight of maleic anhydride and 3 parts by weight of dicumyl peroxide were dissolved in 130 parts by weight of tertiary butylbenzene, and reacted at 140°C for 6 hours. The reaction product solution was poured into methanol to coagulate the reaction product. This condensate was dried with a vacuum dryer (220°C, 1 Torr) for 6 hours to obtain a maleic acid-modified ring-opening polymer hydride (polymer (C5)). The Mw of the polymer (C5) was 5.6×10 ⁴ and the Mw/Mn was 2.5. The Tg of the polymer (C5) was 170° C., the C _R was 2000×10 ⁻¹² Pa ⁻¹ , and the maleic acid group content rate was 25 mol%.

[Evaluation method]

(Measurement of Rth, Re, d of stretched film and calculation of Rth/d)

The retardation Rth in the thickness direction and the retardation Re in the in-plane direction of the stretched films obtained in Examples and Comparative Examples, respectively, were measured at a measurement wavelength of 550 nm using a phase difference meter ("AXOSCAN" manufactured by AXOMETRICS). The thickness d of the stretched films obtained in Examples and Comparative Examples, respectively, was measured by caliper ID-C112BS (manufactured by Mitutoyo Co., Ltd.).

The measured Rth value was divided by the thickness d of the stretched film to calculate Rth/d and evaluated by the following evaluation criteria. The results are shown in Table 1 and Table 2. In Tables 1 and 2, Rth/d is described in the upper row, and the evaluation results are described in parentheses in the lower row. Good: 3.5×10 ⁻³ or more Bad: Less than 3.5×10 ⁻³

(Direction angle accuracy)

The orientation angle θ of the stretched film obtained in Examples and Comparative Examples was measured using a polarizing microscope (made by Olympus, polarizing microscope "BX51"), and the absolute value was calculated as the orientation angle. At an interval of 50 mm with respect to the width direction of the stretched film and an interval of 10 m with respect to the length direction, the orientation angle θ was measured. The standard deviation of these measurement results was calculated and determined as the orientation angle accuracy θσ. The results are shown in Table 1 and Table 2. The accuracy of the orientation angle is smaller and the variation of the orientation angle is smaller.

(Evaluation method of delamination)

<Measurement method of peel strength>

Prepare a film (Zeonor Film, glass transition temperature 160°C, thickness 100 μm, made by Japan Ruion Corporation, which has not been specially subjected to stretching treatment) containing a resin containing a vinylene-based polymer as the adherend. Corona treatment was applied to one side of the film to be measured (stretched films obtained in Examples and Comparative Examples, respectively) and one side of the adherend. Attaching the bonding agent to both the corona-treated surface of the film to be measured and the corona-treated surface of the adherend will bond the adhesive-attached surfaces to each other. At this time, as a bonding agent, a UV bonding agent CRB series (manufactured by TOYOCHEM CO., LTD.) was used. After that, using an electrodeless UV irradiation device (manufactured by Heraeus), using a D bulb as the light source, UV irradiation was performed under the conditions of a peak illuminance of 100 mW/cm ² and an integrated light amount of 3000 mJ/cm ² to cure the bonding agent. . By this, a sample film including the film to be measured and the adherend is obtained.

A 90-degree peel test was performed on the obtained sample film. That is, the sample film is cut to a width of 15 mm, and the side of the film to be measured is attached to the surface of the slide glass with an adhesive. At this time, as an adhesive, double-sided adhesive tape (manufactured by Nitto Denko Corporation, model "CS9621") was used. Clamp the to-be-adhered body at the end of the high-performance digital dynamometer ZP-5N (manufactured by IMADA) and pull the to-be-adhered body at a speed of 300 mm/min along the normal direction of the surface of the glass slide to measure the traction The magnitude of the force is taken as the peel strength. The evaluation of the peel strength was carried out by the following evaluation criteria, and the results are shown in Table 1 and Table 2. In Table 1 and Table 2, the measured value is described in the upper paragraph, and the evaluation result is described in the parentheses in the lower paragraph. Good: 1.0 N/15 mm or more Bad: less than 1.0 N／15 mm

<Reference example: Evaluation of the validity of the peel strength measurement method>

Experiments were conducted to evaluate whether the "peel strength measurement using the above-mentioned measurement method reflects the evaluator of peel strength in the case of a polarizer bonded to a system".

The polarizing film and the adhesive were prepared by the same method as described in Example 1 of Japanese Patent Publication No. 2005-70140. Furthermore, the stretched film obtained in Example 1 of the present application is prepared as a film to be measured. Corona treatment is applied to one side of the film to be measured, and the intermediary bonding agent is applied to one surface of the polarizing film. On the other surface of the polarizing film, an intermediary bonding agent is attached to the cellulose triacetate film. After that, it was dried at 80°C for 7 minutes to cure the bonding agent to obtain a sample film. The obtained sample film was subjected to the same 90-degree peel test as in the "Measurement Method of Peel Strength" described above. As a result, a peel strength value similar to that obtained in Example 1 of the present application can be obtained. From this fact, it can be said that the measurement of the peel strength used in the above-mentioned measurement method reflects the evaluator of the peel strength in the case of the polarizer of the bonded system.

(Rth change rate after 85 hours at 85℃)

For each stretched film of Examples and Comparative Examples, an endurance test at 85°C for 500 hours was performed, and the Rth of the stretched film before and after the test was measured, and the rate of change was calculated by the following formula and evaluated by the following criteria. Those with a small rate of change have high heat resistance, which is better. In Tables 1 and 2, the rate of change is described in the upper stage, and the evaluation results are shown in parentheses in the lower stage. Rate of change (%) = (Rth before test-Rth after test) / Rth before test × 100 Good: The rate of change is below 3% Bad: The rate of change is greater than 3%

(60°C, humidity 90%, Rth change rate after 500 hours)

For each stretched film of Examples and Comparative Examples, a durability test was conducted at 60°C, 90% humidity, and 500 hours. The Rth of the stretched film before and after the test was measured, and the rate of change was calculated by the following formula, and by the following criteria To evaluate. Those with a small change rate have high heat resistance and moisture resistance, which is better. In Tables 1 and 2, the rate of change is described in the upper stage, and the evaluation results are shown in parentheses in the lower stage. Rate of change (%) = (Rth before test-Rth after test) / Rth before test × 100 Good: The rate of change is below 3% Bad: The rate of change is greater than 3%

(Measurement of water absorption)

A part of each stretched film of Examples and Comparative Examples was cut to prepare a test piece (size: 100 mm×100 mm), and the quality of the test piece was measured. After that, the test piece was immersed in water at 23°C for 24 hours, and the quality of the test piece after immersion was measured. Then, the ratio of the mass of the test piece increased by dipping to the mass of the test piece before dipping was calculated as the water absorption rate (%). The water absorption rate is better with the smaller one.

(Example 1)

(1-1) Manufacture of film before stretching

The polymer (1) produced in Production Example 1 was put into a biaxial extruder and formed into a strand-shaped shaped body by hot melt extrusion. This molded body was finely cut with a strand cutter to obtain resin particles containing the polymer (1).

After the resin pellets were dried at 100°C for 5 hours, the pellets were fed to an extruder by a conventional method, melted at 250°C, and discharged from a mold onto a cooling drum to obtain a pre-stretch film with a thickness of 110 μm.

(1-2) Manufacture of stretched film

Secondly, using a longitudinal stretching machine using a floating method between the rolls, the film before stretching was stretched 1.2 times in the longitudinal direction at 138°C (Tg + 10°C). The longitudinally stretched film is further fed to a transverse stretching machine using a tenter method to adjust the drawing tension and the tenter chain tension, and at the same time, it is stretched 1.4 times in the transverse direction at a temperature of 138°C (Tg + 10°C) to obtain biaxial stretching film. The obtained biaxially stretched film has Re of 60 nm, Rth of 320 nm, and a thickness d of 65 μm. The evaluation test was performed on the obtained biaxially stretched film, and the results are shown in Table 1.

[Example 2]

(2-1) Manufacture of film before stretching

Except that the polymer (2) produced in Production Example 2 was used instead of the polymer (1) in (1-1) of Example 1, the same operation as (1-1) of Example 1 was performed to obtain The film (2) has a thickness of 118 μm before stretching.

(2-2) Manufacture of stretched film

Secondly, using a longitudinal stretching machine using a floating method between the rolls, the film before stretching was stretched to 1.25 times in the longitudinal direction at 146°C (Tg + 10°C). The longitudinally stretched film is further fed to a transverse stretching machine using a tenter method to adjust the drawing tension and the tenter chain tension, and at the same time, it stretches in the transverse direction at a temperature of 146°C (Tg + 10°C) by 1.45 times to obtain biaxial stretching. film. The obtained biaxially stretched film has a Re of 60 nm, a Rth of 310 nm, and a thickness d of 65 μm. The evaluation test was performed on the obtained biaxially stretched film, and the results are shown in Table 1.

[Example 3]

(3-1) Manufacture of film before stretching

Except that the polymer (3) produced in Production Example 3 was used instead of the polymer (1) in (1-1) of Example 1, the same operation as (1-1) of Example 1 was performed to obtain The pre-stretch film with thickness 127 μm of object (3).

(3-2) Manufacture of stretched film

Next, using a longitudinal stretching machine using a floating method between the rolls, the film before stretching was stretched 1.3 times in the longitudinal direction at 138°C (Tg + 10°C). The longitudinally stretched film is further fed to a transverse stretching machine using a tenter method to adjust the drawing tension and the tension of the tenter chain, and at the same time stretch 1.5 times in the transverse direction at a temperature of 138°C (Tg + 10°C) to obtain biaxial stretching film. The obtained biaxially stretched film has a Re of 60 nm, a Rth of 300 nm, and a thickness d of 65 μm. The evaluation test was performed on the obtained biaxially stretched film, and the results are shown in Table 1.

[Comparative Example 1]

(C1-1) Manufacture of film before stretching

Except that the polymer (C1) produced in Production Example 4 was used in Example 1 (1-1) instead of the polymer (1) and the discharge amount of molten resin was increased, the same procedure as in Example 1 (1-1) was carried out ) The same operation was performed to obtain a pre-stretch film with a thickness of 180 μm containing polymer (C1).

(C1-2) Manufacture of stretched film

Secondly, using a longitudinal stretching machine using a floating method between the rolls, the film before stretching was stretched 1.4 times in the longitudinal direction at 139°C (Tg + 10°C). The longitudinally stretched film is further fed to a transverse stretching machine using a tenter method to adjust the drawing tension and the tenter chain tension, and at the same time, it is stretched 1.6 times in the transverse direction at a temperature of 139°C (Tg + 10°C) to obtain biaxial stretching film. The obtained biaxially stretched film has a Re of 60 nm, a Rth of 300 nm, and a thickness of 80 μm. The evaluation test was performed on the obtained biaxially stretched film, and the results are shown in Table 1.

[Comparative Example 2]

(C2-1) Manufacture of film before stretching

Except that the polymer (C2) produced in Production Example 5 was used in Example 1 (1-1) instead of the polymer (1) and the discharge amount of molten resin was increased, the same procedure as in Example 1 (1-1) was carried out ) The same operation was performed to obtain a pre-stretch film with a thickness of 198 μm containing polymer (C2).

(C2-2) Manufacture of stretched film

Secondly, using a longitudinal stretching machine using a floating method between the rolls, the film before stretching was stretched to 1.65 times in the longitudinal direction at 146°C (Tg + 10°C). The longitudinally stretched film is further fed to a transverse stretching machine using a tenter method to adjust the drawing tension and the tenter chain tension, and at the same time, it is stretched to 1.85 times in the transverse direction at a temperature of 146°C (Tg + 10°C) to obtain biaxial stretching. film. The obtained biaxially stretched film has a Re of 60 nm, a Rth of 250 nm, and a thickness d of 65 μm. The evaluation test was performed on the obtained biaxially stretched film, and the results are shown in Table 1.

[Comparative Example 3]

(C3-1) Manufacture of film before stretching

Except that the polymer (C3) produced in Production Example 6 was used in Example 1 (1-1) instead of the polymer (1) and the discharge amount of molten resin was increased, the same procedure as in Example 1 (1-1) was carried out ) By the same operation, a film with a thickness of 188 μm including the polymer (C3) before stretching is obtained.

(C3-2) Manufacture of stretched film

Secondly, using a longitudinal stretching machine using a floating method between the rolls, the film before stretching was stretched 1.6 times in the longitudinal direction at 138°C (Tg + 10°C). The longitudinally stretched film is further fed to a transverse stretching machine using a tenter method to adjust the drawing tension and the tenter chain tension, and at the same time, it is stretched 1.8 times in the transverse direction at a temperature of 138°C (Tg + 10°C) to obtain biaxial stretching film. The obtained biaxially stretched film has a Re of 60 nm, a Rth of 250 nm, and a thickness d of 65 μm. An evaluation test was performed on the obtained biaxially stretched film, and the results are shown in Table 2.

[Comparative Example 4]

(C4-1) Manufacture of film before stretching

Except that the polymer (C4) produced in Production Example 7 was used instead of the polymer (1) in (1-1) of Example 1, the same operation as (1-1) of Example 1 was performed to obtain The film (C4) has a thickness of 136 μm before stretching.

(C4-2) Manufacture of stretched film

Secondly, using a longitudinal stretching machine using a floating method between the rolls, the film before stretching was stretched by 1.35 times at 112°C (Tg + 10°C) in the longitudinal direction. The longitudinally stretched film is further fed to a transverse stretching machine using a tenter method to adjust the drawing tension and the tenter chain tension, and at the same time, it is stretched 1.55 times in the transverse direction at a temperature of 112°C (Tg + 10°C) to obtain biaxial stretching film. The obtained biaxially stretched film has a Re of 60 nm, a Rth of 300 nm, and a thickness of 65 μm. An evaluation test was performed on the obtained biaxially stretched film, and the results are shown in Table 2.

[Comparative Example 5]

(C5-1) Manufacture of film before stretching

Except that the polymer (C3) produced in Production Example 6 was used instead of the polymer (1) in (1-1) of Example 1, the same operation as (1-1) of Example 1 was performed to obtain The film (C3) has a thickness of 134 μm before stretching.

(C5-2) Manufacture of stretched film

Secondly, using a longitudinal stretching machine using a floating method between the rolls, the film before stretching was stretched 1.2 times in the longitudinal direction at 138°C (Tg + 10°C). The longitudinally stretched film is further fed to a transverse stretching machine using a tenter method to adjust the drawing tension and the tenter chain tension, and at the same time, it is stretched 1.4 times in the transverse direction at a temperature of 138°C (Tg + 10°C) to obtain biaxial stretching film. The obtained biaxially stretched film has a Re of 60 nm, a Rth of 260 nm, and a thickness of 80 μm. An evaluation test was performed on the obtained biaxially stretched film, and the results are shown in Table 2.

[Comparative Example 6]

(C6-1) Manufacture of film before stretching

Except that the polymer (C5) produced in Production Example 8 was used in Example 1 (1-1) instead of the polymer (1) and the discharge amount of molten resin was increased, the same procedure as in Example 1 (1-1) was carried out ) The same operation was performed to obtain a pre-stretch film with a thickness of 192 μm containing polymer (C5).

(C6-2) Manufacture of stretched film

Secondly, using a longitudinal stretching machine using a floating method between the rolls, the film before stretching was stretched 1.62 times in the longitudinal direction at 180°C (Tg + 10°C). The longitudinally stretched film is further supplied to a transverse stretcher using a tenter method to adjust the tension of tension and the tension of the tenter chain, and at the same time, it is stretched 1.82 times in the transverse direction at a temperature of 180°C (Tg + 10°C) to obtain biaxial stretching film. The obtained biaxially stretched film has Re of 60 nm, Rth of 250 nm, and a thickness of 65 μm. An evaluation test was performed on the obtained biaxially stretched film, and the results are shown in Table 2.

The evaluation results of Examples and Comparative Examples are disclosed in the following table. In the following table, the meaning of the abbreviations is as follows. MRu: Non-aromatic unsaturated bonds are subject to selective hydrogenation and aromatic unsaturated bonds have residual MTF. T: hydrogenated TCD. D: Hydrogenated DCPD. M: hydrogenated MTF (that is, MTF in which both non-aromatic unsaturated bonds and aromatic unsaturated bonds are subjected to hydrogenation). Polar COP: cycloolefin polymer with polar groups. MD × TD: vertical extension magnification × horizontal extension magnification.

"Table 1"

"Table 2"

[result]

As shown in Table 1 and Table 2, in the stretched film of the embodiment satisfying the requirements of the present invention, although the stretch ratio is low but the Rth/d is high, the occurrence of delamination is suppressed. As a result, it can be seen that the film that satisfies the requirements of the present invention can provide a viewing angle compensation film that is excellent in phase difference expressibility and has a high retardation in the thickness direction.

no.

no.

no.

Claims (6)

An optical film, which is an optical film made of thermoplastic resins, and is an extended film, wherein the stress birefringence C _{R of the} thermoplastic resins is greater than 2900×10 ⁻¹² Pa ⁻¹ , glass transfer The temperature Tg is 125° C. or higher, and the ratio of the retardation Rth in the thickness direction of the optical film to the thickness d (Rth/d) is 3.5×10 ⁻³ or more. The optical film according to claim 1, the retardation Re in the in-plane direction is 40 nm or more and 80 nm or less. The optical film according to claim 1, wherein the thermoplastic norbornene-based resin includes a polymer, and the aforementioned polymer includes a norbornene-based monomer unit having an aromatic ring structure. The optical film according to claim 3, wherein the polymer contains 25% by weight or more of the aforementioned vinylene monomer unit having an aromatic ring structure. An optical stack comprising: the optical film according to any one of claims 1 to 4; and a polarizing plate provided on the optical film. A liquid crystal display device comprising the optical stack according to claim 5.