JP2013029792A - Cyclic olefin-based resin film, polarizing plate, and liquid crystal display unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cyclic olefin-based resin film, which has a large Rth and an extremely small Re with no substantial phase difference.SOLUTION: A cyclic olefin-based resin film which contains a cyclic olefin-based resin and satisfies the following expressions (1) to (4): |Re|≤4nm (1); 50nm≤Rth≤300nm (2); 10 μm≤d≤70 μm (3); and 1×10≤Rth/d≤1×10(4); wherein Re represents a retardation value in the in-plane direction of the film, Rth represents a retardation value in the thickness direction of the film, and d represents the thickness of the film.

Description

  The present invention relates to a cyclic olefin resin film and a method for producing the same. More specifically, the present invention relates to a cyclic olefin-based resin film that includes a cyclic olefin polymer, has a large Rth, and has a uniform in-plane display when attached to a panel after polarizing plate processing, and a method for producing the same. The present invention also relates to a polarizing plate and a liquid crystal display device using the optical film.

  In recent years, liquid crystal display devices have been made thinner, and this tendency is particularly noticeable for television liquid crystal display devices that require high added value such as high quality and large screen. Accordingly, thinning of each component is required, but in particular, film-shaped members such as polarizing plates and optical compensation films satisfy suitable requirements for thinning, and at the same time have suitable optical performance and mechanical properties. There is a need for optical films.

  Also, in designing optical performance, apart from the trend of thinning due to the functional compounding of optical films such as the use of biaxial films, it is possible to design for various operation modes of liquid crystals and ease of selection and introduction of member configurations. So-called A plate having a phase difference only in the in-plane direction and a so-called C plate having a phase difference only in the thickness direction in order to ensure robustness against performance fluctuations due to environments such as humidity and heat, and to ensure rigidity Lamination of a uniaxial film is also being studied, and when considering a highly versatile uniaxial film, particularly a reduction in thickness, the need for a C plate having a retardation only in the thickness direction will increase. Conceivable.

Patent Document 1 shows a film made of a cyclic olefin polymer suitable for laminating an optically anisotropic layer, but the thickness direction retardation of this film is not studied and laminated. The C plate is provided with retardation in the thickness direction by the optically anisotropic layer.
Patent Document 2 describes a C plate made of a cyclic olefin polymer, but retardation in the thickness direction is obtained, but there is some retardation in the in-plane direction. It was insufficient as a high uniaxial film.

JP 2004-246339 A Japanese Patent No. 4373335

  With respect to the cyclic olefin polymer that is the material of the optical film, the higher the expression of the retardation, the higher the thickness direction retardation Rth is obtained, but at the same time, the in-plane direction retardation Re is generated. It was very difficult to have a performance close to.

  That is, the problem to be solved by the present invention is that the cyclic olefin polymer is used, the retardation Rth in the thickness direction is large, and the retardation Re in the in-plane direction is so small that it has substantially no phase difference. The object is to provide a cyclic olefin-based resin film. Moreover, it is providing the polarizing plate and liquid crystal display device which use this cyclic olefin resin film.

As a result of intensive studies by the inventor with respect to the above problems, by adopting specific manufacturing conditions, it is possible to provide various optical films that can solve the above problems while achieving both the above physical properties and optical characteristics. I found that I can do it.
Specifically, the above problem has been solved by the following means.

[1]
The cyclic olefin resin film which contains cyclic olefin resin and satisfy | fills following formula (1)-(4).
| Re | ≦ 4nm (1)
50 nm ≦ Rth ≦ 300 nm (2)
10 μm ≦ d ≦ 70 μm (3)
1 × 10 ⁻³ ≦ Rth / d ≦ 1 × 10 ⁻² (4)
In the formula, Re is the retardation value in the in-plane direction of the film, Rth is the retardation value in the thickness direction of the film, and d is the thickness of the film.
[2]
The cyclic olefin-based resin film according to [1], wherein ΔRth (RH) represented by the following formula (4) is less than 10.
Rth (RH) = | Rth (10%) − Rth (80%) | (4)
In the formula, Rth (10%) is the Rth of the film measured in an environment of 25 ° C. and 10% RH, and Rth (80%) is the Rth of the film measured in an environment of 25 ° C. and 80% RH.
[3]
The cyclic olefin resin film according to [1] or [2], wherein the cyclic olefin resin film is formed by a solution casting method.
[4]
The cyclic olefin resin film according to [3], wherein the cyclic olefin resin film contains a plasticizer or a retardation developer.
[5]
The cyclic olefin resin film according to [1] or [2], wherein the cyclic olefin resin film is formed by a melt film forming method.
[6]
The cyclic olefin resin film according to [5], wherein the cyclic olefin resin film is formed by a biaxial stretching process.
[7]
The polarizing plate using the cyclic olefin resin film as described in any one of [1]-[6].
[8]
The liquid crystal display device using the cyclic olefin resin film as described in any one of [1]-[6], or the polarizing plate as described in [7].

According to the present invention, it is possible to provide a cyclic olefin-based resin film having a large Rth and an extremely small Re so as not to have a phase difference, and a polarizing plate using the film. In addition, the cyclic olefin-based resin film of the present invention provides a liquid crystal display device that can be easily designed for various operation modes of liquid crystals and can easily select and introduce member configurations, and has stability against environmental fluctuations such as humidity and heat. Is possible.

  Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described below may be made based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value. In the present specification, the film transport direction may be referred to as the longitudinal direction, the film longitudinal direction, or the MD direction, and the direction orthogonal to the film transport direction may be referred to as the lateral direction, the film width direction, or the TD direction. .

[Cyclic olefin resin film]
The cyclic olefin resin film of the present invention (hereinafter also referred to as the film of the present invention) is a cyclic olefin resin film that includes a cyclic olefin resin and satisfies the following formulas (1) to (4).
| Re | ≦ 4nm (1)
50 nm ≦ Rth ≦ 300 nm (2)
10 μm ≦ d ≦ 70 μm (3)
1 × 10 ⁻³ ≦ Rth / d ≦ 1 × 10 ⁻² (4)
In the formula, Re is the retardation value in the in-plane direction of the film, Rth is the retardation value in the thickness direction of the film, and d is the thickness of the film.

<Film characteristics>
(Retardation)
Re and Rth are defined by the following formula.
Re = (nx−ny) × d
Rth = ((nx + ny) / 2−nz) × d (formula (12) described later)
In the formula, nx represents the refractive index in the slow axis direction in the film plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the refractive index in the direction perpendicular to nx and ny. . d is the film thickness (film thickness in the nz direction).

In the present specification, Re (λ) and Rth (λ) respectively represent an in-plane retardation value and a thickness direction retardation value at a wavelength λ. In the present specification, unless otherwise specified, the wavelength λ is 550 nm, and is simply expressed as Re and Rth. Re (λ) is measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments). In selecting the measurement wavelength λnm, the wavelength selection filter can be exchanged manually, or the measurement value can be converted by a program or the like.
When the film to be measured is represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) is calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (if there is no slow axis, any in-plane film The light is incident at a wavelength of λ nm from the inclined direction in steps of 10 degrees from the normal direction to 50 degrees on one side with respect to the film normal direction of the rotation axis of KOBRA 21ADH or WR is calculated based on the measured retardation value, the assumed value of the average refractive index, and the input film thickness value.
In the above case, in the case of a film having a direction in which the retardation value is zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, retardation at a tilt angle larger than the tilt angle. The value is calculated by KOBRA 21ADH or WR after changing its sign to negative.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (in the absence of the slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the assumed value of the average refractive index, and the input film thickness value, Rth can also be calculated from the following equations (11) and (12).

The above Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction.
Formula (12): Rth = {(nx + ny) / 2−nz} xd
In formulas (11) and (12), nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the direction in the direction perpendicular to nx and ny. Refractive index. d is the film thickness.

In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) is calculated by the following method.
Rth (λ) is from −50 degrees to +50 degrees with respect to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or WR) and the tilt axis (rotating axis). In each of the 10 degree steps, light of wavelength λ nm is incident from the inclined direction and measured at 11 points. Based on the measured retardation value, the assumed average refractive index, and the input film thickness value, KOBRA 21ADH or WR is calculated.

  In the above measurement, as the assumed value of the average refractive index, the values in the polymer handbook (JOHN WILEY & SONS, INC) and catalogs of various optical films can be used. Those whose average refractive index is not known can be measured with an Abbe refractometer. The average refractive index values of main optical films are exemplified below: cellulose acylate (1.48), cycloolefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), Polystyrene (1.59). The KOBRA 21ADH or WR calculates nx, ny, and nz by inputting the assumed value of the average refractive index and the film thickness. Nz = (nx−nz) / (nx−ny) is further calculated from the calculated nx, ny, and nz.

The film of the present invention has | Re | ≦ 4 nm and can be regarded as having substantially no Re. It is preferable that | Re | ≦ 2 nm.
Rth satisfies 50 nm ≦ Rth ≦ 300 nm, preferably satisfies 55 nm ≦ Rth ≦ 150 nm, and more preferably satisfies 65 nm ≦ Rth ≦ 150 nm. By using such Rth, a thin-film C plate with higher Rth expression can be produced.

(Rth / d)
The film of the present invention satisfies the following formula (4). As a result, it is possible to achieve both a reduction in film thickness and sufficient Rth expression, and lower the raw material cost of the film.
1 × 10 ⁻³ ≦ Rth / d ≦ 1 × 10 ⁻² (4)
(In the formula, Rth represents the retardation value (unit: nm) in the film thickness direction at a wavelength of 550 nm, and d represents the film thickness (unit: nm).)
Preferably the Rth / d is 1.3~9.5 × ^{10 -3,} more preferably 1.3 to 9.0 × ^{10 -3.}

(ΔRth (RH))
The film of the present invention preferably has a small ΔRth (RH) represented by the following formula (5) from the viewpoint of preventing performance deterioration due to humidity change.
ΔRth (RH) = | Rth (10%) − Rth (80%) | (5)
In the formula, Rth (10%) is the Rth of the film measured in an environment of 25 ° C. and 10% RH, and Rth (80%) is the Rth of the film measured in an environment of 25 ° C. and 80% RH.
Rth (RH) is preferably less than 10, and more preferably less than 5.

(Elastic modulus)
In the film of the present invention, the elastic modulus E ′ of the film preferably satisfies the following formula (6).
1.0 GPa <E ′ <5.0 GPa (6)
(In the formula, E ′ represents the elastic modulus (unit: GPa) of the film.)
The use of a film satisfying such physical properties is preferable because it does not impair the self-supporting property even when the area is increased and has good handling properties when used as a support for a laminate.
The elastic modulus E ′ in the TD direction or MD direction of the film is preferably 1.0 to 5.0 GPa, and more preferably 1.5 to 4.5 GPa.
Further, E ′ (TD) / E ′ (MD), which is the ratio of the elastic modulus in the TD direction to the MD direction, is preferably 0.9 to 1.1, and preferably 0.95 to 1.05. Is more preferable and 1.0 is particularly preferable.

(Film thickness)
The thickness d of the film of the present invention satisfies 10 μm ≦ d ≦ 70 μm, and more preferably 35-60 μm. By setting the thickness of the film to 70 μm or less, it is possible to contribute to a reduction in thickness by the member, and it is possible to reduce costs by reducing the amount of raw materials used, and it is preferable.

(Film width)
The film of the present invention preferably has a film width of 1000 mm or more, more preferably 1500 mm or more, and particularly preferably 1800 mm or more.

<Cyclic olefin resin>
The cyclic olefin resin (also referred to as cyclic polyolefin or cyclic polyolefin resin) used in the cyclic olefin resin film of the present invention will be described.
In the present invention, the cyclic polyolefin resin represents a polymer resin having a cyclic olefin structure. Examples of polymer resins having a cyclic olefin structure include (1) a norbornene polymer, (2) a polymer of a monocyclic olefin, (3) a polymer of a cyclic conjugated diene, and (4) a vinyl alicyclic type. There are hydrocarbon polymers and hydrides of (1) to (4). For example, an addition (co) polymer cyclic polyolefin containing at least one repeating unit represented by the following general formula (II) and, if necessary, at least one repeating unit represented by the general formula (I) Further included are addition (co) polymer cyclic polyolefins. Moreover, the ring-opening (co) polymer containing at least 1 sort (s) of the cyclic repeating unit represented by general formula (III) can also be mentioned.

In formula, m represents the integer of 0-4. R ^{1 to} R ⁶ are a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, X ^{1 to} X ³ and Y ^{1 to} Y ³ are a hydrogen atom, a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, and a halogen atom. substituted hydrocarbon group having 1 to 10 carbon ^{_{atoms, - (CH 2) nCOOR 11}} , - (CH 2) nOCOR 12, - (CH 2) nNCO, - (CH 2) nNO 2, - (CH 2) nCN ^{_{, - (CH 2) nCONR 13}} R 14, - (CH 2) nNR 13 R 14, - (CH 2) nOZ, - (CH 2) nW, or X ¹ and Y ¹ or X ² and Y ² or X ³ And (—CO) ₂ O, (—CO) ₂ NR ¹⁵ composed of Y ³ . R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ are hydrogen atoms, hydrocarbon groups having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ pD. ₃ -p (R ¹⁶ is a hydrocarbon group having 1 to 10 carbon atoms, D is a halogen atom —OCOR ¹⁶ or —OR ¹⁶ , p is an integer of 0 to 3), and n is an integer of 0 to 10.

By introducing a polarizable large functional group in a substituent ^{X 1 ~X 3, Y 1 ~Y} 3, it is possible to increase the thickness direction retardation of the optical film (Rth).

Norbornene-based polymer hydrides are disclosed in JP-A-1-240517, JP-A-7-196736, JP-A-60-26024, JP-A-62-19807, JP-A-2003-159767, or JP-A-2004-309979. As disclosed in No. 1, etc., a polycyclic unsaturated compound is produced by addition polymerization or metathesis ring-opening polymerization and then hydrogenation. In the norbornene-based polymer used in the present invention, R ^{5 to} R ⁶ are preferably a hydrogen atom or —CH ₃ , X ³ and Y ³ are preferably a hydrogen atom, Cl, —COOCH ₃ , and other groups are appropriately selected. The This norbornene-based resin is sold under the trade name Arton G or Arton F by JSR Corporation, and from Zeon Corporation, Zeonor ZF14, ZF16, Zeonex 250 or Zeonex. They are commercially available under the trade name 280 and can be used.

  Norbornene-based addition (co) polymers are disclosed in JP-A No. 10-7732, JP-T-2002-504184, US2004229157A1 or WO2004 / 070463A1. It can be obtained by addition polymerization of norbornene-based polycyclic unsaturated compounds. If necessary, norbornene-based polycyclic unsaturated compounds and ethylene, propylene, butene; conjugated dienes such as butadiene and isoprene; nonconjugated dienes such as ethylidene norbornene; acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride It is also possible to carry out addition polymerization with linear diene compounds such as acid, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate and vinyl chloride. This norbornene-based addition (co) polymer is marketed by Mitsui Chemicals, Inc. under the name of Apel, and has different glass transition temperatures (Tg) such as APL8008T (Tg70 ° C), APL6013T (Tg125 ° C) or APL6015T ( Grades such as Tg145 ° C). Pellets such as TOPAS 8007, 6013, and 6015 are sold by Polyplastics Co., Ltd. Further, Appear 3000 is sold by Ferrania.

  In the present invention, the glass transition temperature (Tg) of the cyclic polyolefin is not limited, but a cyclic polyolefin having a high Tg such as 200 to 400 ° C. can also be used.

<Additives>
The film of the present invention may contain various additives.
In the present invention, known high molecular weight additives and low molecular weight additives can be widely employed as additives for cyclic olefin resin films.
In the film of the present invention, the additive amount is preferably 1 to 45% by mass, more preferably 2 to 35% by mass, based on the cyclic olefin resin, as the total amount of various additives. More preferably, it is 4-25 mass%. If the addition amount of the additive is 1% by mass or more, it is easy to cope with changes in temperature and humidity, and if the addition amount is 35% by mass or less, the film is hardly whitened. Furthermore, physical properties are also excellent.
Here, the additive in the present invention refers to a component added for the purpose of improving various functions of the cyclic olefin resin film of the present invention. That is, impurities and residual solvents are not additives in the present invention.

Examples of the additive include plasticizers such as polycondensation esters, acrylic acid ester polymers, phthalic acid esters, phosphoric acid ester compounds, sugar ester compounds; retardation modifiers (retardation enhancers and retardation reductions). Agent); deterioration (oxidation) inhibitor; ultraviolet absorber; matting agent; organic acid (which may be a peeling accelerator) and the like can be added.
In particular, when the film forming method is a solution film forming method, it is preferable to use a retardation developer, an ultraviolet absorber, a plasticizer, and an organic acid. When the manufacturing method is a melt film forming method, a deterioration (oxidation) inhibitor. Is preferably used.
Hereinafter, additives that can be used in the film of the present invention will be described in detail.

(Plasticizer)
<Polycondensed ester>
The polycondensed ester according to the present invention is a mixture of a dicarboxylic acid having at least one aromatic ring (also called an aromatic dicarboxylic acid) and at least one aliphatic dicarboxylic acid, for example, having an average carbon number of 5.5 or more and 10 It is preferably obtained from 0.0 or less dicarboxylic acid and at least one aliphatic diol having an average carbon number of 2.5 or more and 7.0 or less.

Calculation of the average carbon number of the aliphatic dicarboxylic acid residue is performed separately for the dicarboxylic acid residue and the diol residue.
The value calculated by multiplying the composition ratio (molar fraction) of the dicarboxylic acid residue by the constituent carbon number is defined as the average carbon number. For example, when the adipic acid residue and the phthalic acid residue are composed of 50 mol% each, the average carbon number is 7.0.
The same applies to a diol residue. The average carbon number of an aliphatic diol residue is a value calculated by multiplying the constituent carbon number by the composition ratio (molar fraction) of the aliphatic diol residue. For example, when it is composed of 50 mol% of ethylene glycol residues and 50 mol% of 1,2-propanediol residues, the average carbon number is 2.5.

The number average molecular weight of the polycondensed ester is preferably 700 to 2500, more preferably 700 to 1500, and still more preferably 700 to 1200. In the present invention, if the number average molecular weight of the polycondensed ester is 700 or more, the volatility is low, and film failure and process contamination due to volatilization under high temperature conditions during stretching of the cyclic olefin resin film are less likely to occur. Moreover, if it is 2500 or less, compatibility with cyclic olefin resin will become high, and it will become difficult to produce the bleed-out at the time of film forming and at the time of heat-stretching.
The number average molecular weight of the polycondensed ester of the present invention can be measured and evaluated by gel permeation chromatography. Further, in the case of a polyester polyol having an unsealed terminal, it can also be calculated from the amount of hydroxyl group per mass (hereinafter referred to as hydroxyl value). The hydroxyl value is determined by measuring the amount (mg) of potassium hydroxide required for neutralizing excess acetic acid after acetylating the polyester polyol.

The dicarboxylic acid as a mixture of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid according to the present invention is preferably a dicarboxylic acid having an average carbon number of 5.5 or more and 10.0 or less. More preferably, it is 5.6 or more and 8 or less.
If the average number of carbon atoms is 5.5 or more, a film and a polarizing plate excellent in durability can be obtained. If the average number of carbon atoms is 10 or less, the compatibility with the cecyclic olefin resin is excellent, and the occurrence of bleed-out can be suppressed in the process of forming the cyclic olefin resin film.
The polycondensed ester according to the present invention can be used as a plasticizer.

The aromatic dicarboxylic acid residue is contained in a polycondensed ester obtained from a diol and a dicarboxylic acid containing an aromatic dicarboxylic acid.
In the present specification, a residue is a partial structure of a polycondensed ester and represents a partial structure having the characteristics of a monomer forming the polycondensed ester. For example, the dicarboxylic acid residue formed from dicarboxylic acid HOOC-R-COOH is -OC-R-CO-.
The ratio of aromatic dicarboxylic acid residues in the polycondensed ester used in the present invention is preferably 40 mol% or more, and preferably 40 mol% to 95 mol%. More preferably, it is 45 mol%-70 mol%, and still more preferably 50 mol%-70 mol%.
By setting the aromatic dicarboxylic acid residue ratio to 40 mol% or more, a cyclic olefin resin film exhibiting sufficient optical anisotropy can be obtained, and a film and a polarizing plate excellent in durability can be obtained. Moreover, if it is 95 mol% or less, it is excellent in compatibility with cyclic olefin-type resin, and it can make it difficult to produce a bleed-out also at the time of film production of a cyclic olefin-type resin film and at the time of heat-stretching.

Examples of the aromatic dicarboxylic acid used in the present invention include phthalic acid, terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, and 2,8-naphthalene. Examples thereof include dicarboxylic acid and 2,6-naphthalenedicarboxylic acid. Phthalic acid, terephthalic acid and 2,6-naphthalenedicarboxylic acid are preferred, phthalic acid and terephthalic acid are more preferred, and terephthalic acid is even more preferred.
In the polycondensed ester, an aromatic dicarboxylic acid residue is formed by the aromatic dicarboxylic acid used for mixing.
Specifically, the aromatic dicarboxylic acid residue preferably includes at least one of a phthalic acid residue, a terephthalic acid residue, and an isophthalic acid residue, more preferably a phthalic acid residue or a terephthalic acid residue. It contains at least one, and more preferably contains a terephthalic acid residue.
That is, by using terephthalic acid as the aromatic dicarboxylic acid for mixing in the formation of the polycondensed ester, it is more compatible with the cyclic olefin resin, and at the time of film formation and heat stretching of the cyclic olefin resin film. It can be set as the cyclic olefin resin film which hardly produces bleed-out. Moreover, aromatic dicarboxylic acid may be used alone or in combination of two or more. When two types are used, it is preferable to use phthalic acid and terephthalic acid.
By using together two kinds of aromatic dicarboxylic acids of phthalic acid and terephthalic acid, the polycondensation ester at normal temperature can be softened, which is preferable in terms of easy handling.
The content of the terephthalic acid residue in the dicarboxylic acid residue of the polycondensed ester is preferably 40 mol% to 95 mol%, preferably 45 mol% to 70 mol%, and preferably 50 mol% to 70 mol%. .
By setting the terephthalic acid residue ratio to 40 mol% or more, a cyclic olefin-based resin film exhibiting sufficient optical anisotropy can be obtained. Moreover, if it is 95 mol% or less, it is excellent in compatibility with cyclic olefin-type resin, and it can make it difficult to produce a bleed-out also at the time of film production of a cyclic olefin-type resin film and at the time of heat-stretching.

The aliphatic dicarboxylic acid residue is contained in a polycondensed ester obtained from a diol and a dicarboxylic acid containing an aliphatic dicarboxylic acid.
In the present specification, a residue is a partial structure of a polycondensed ester and represents a partial structure having the characteristics of a monomer forming the polycondensed ester. For example, the dicarboxylic acid residue formed from dicarboxylic acid HOOC-R-COOH is -OC-R-CO-.
Examples of the aliphatic dicarboxylic acid preferably used in the present invention include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and dodecanedicarboxylic acid. Examples include acid or 1,4-cyclohexanedicarboxylic acid.
In the polycondensed ester, an aliphatic dicarboxylic acid residue is formed from the aliphatic dicarboxylic acid used for mixing.
The average number of carbon atoms of the dicarboxylic acid residue is preferably 5.5 or more, 10.0 or less, more preferably 5.5 to 8.0, and even more preferably 5.5 to 7.0. preferable. If the average carbon number of the aliphatic diol is 7.0 or less, the heat loss of the compound can be reduced, and the occurrence of surface failure that may be caused by process contamination due to bleed-out during the web drying of the cyclic olefin resin is prevented. Can do. Moreover, it is preferable that the aliphatic diol has an average carbon number of 2.5 or more because the compatibility is excellent and precipitation of the polycondensed ester hardly occurs.
Specifically, it preferably includes a succinic acid residue, and when two types are used, it preferably includes a succinic acid residue and an adipic acid residue.
That is, one or two or more aliphatic dicarboxylic acids may be used for mixing in the formation of the polycondensed ester. When two types are used, it is preferable to use succinic acid and adipic acid. When using 1 type, it is preferable to use a succinic acid. The average carbon number of the diol residue can be adjusted to a desired value, which is preferable in terms of compatibility with the cyclic olefin resin.

  In the present invention, two or three dicarboxylic acids are preferably used. When two types are used, it is necessary to use one type of aliphatic dicarboxylic acid and one type of aromatic dicarboxylic acid. When three types are used, one type of aliphatic dicarboxylic acid and two types of aromatic dicarboxylic acid are used. Two types of aromatic dicarboxylic acids and one type of aromatic dicarboxylic acid can be used. This is because the average carbon number value of the dicarboxylic acid residue can be easily adjusted, the content of the aromatic dicarboxylic acid residue can be within a preferable range, and the durability of the film can be improved.

The aliphatic diol residue is contained in a polycondensed ester obtained from an aliphatic diol and a dicarboxylic acid containing a dicarboxylic acid.
In the present specification, a residue is a partial structure of a polycondensed ester and represents a partial structure having the characteristics of a monomer forming the polycondensed ester. For example, the diol residue formed from the diol HO—R—OH is —O—R—O—.
Examples of the diol that forms the polycondensed ester include aromatic diols and aliphatic diols, and at least aliphatic diols are included.
The polycondensed ester preferably contains an aliphatic diol residue having an average carbon number of 2.5 or more and 7.0 or less. An aliphatic diol residue having an average carbon number of 2.5 or more and 4.0 or less is preferable. If the average number of carbon atoms of the aliphatic diol residue is 3.0 or less, the compatibility with the cyclic olefin-based resin is not lowered, bleed-out hardly occurs, and the heat loss of the compound does not increase too much. It is difficult for a sheet-like failure to occur due to process contamination at the time of web drying of the cyclic olefin resin. Further, when the average carbon number of the aliphatic diol residue is less than 2.0, the synthesis becomes difficult.
Examples of the aliphatic diol used in the present invention include alkyl diols and alicyclic diols, such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 2,2-diethyl-1,3-propanediol (3,3-dimethylolpentane), 2-n-butyl-2-ethyl-1,3-propanediol (3,3-dimethylolheptane), 3- Methyl-1,5-pentanediol, 1,6-hexanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl -1,3-hexanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-octadecanediol, diethylene glycol, cyclohexanedimethanol, etc. Is preferably used together with ethylene glycol as one or a mixture of two or more.

The preferred aliphatic diol is at least one of ethylene glycol, 1,2-propanediol, and 1,3-propanediol, and particularly preferably at least one of ethylene glycol and 1,2-propanediol. . When two types are used, it is preferable to use ethylene glycol and 1,2-propanediol. By using 1,2-propanediol or 1,3-propanediol, crystallization of the polycondensed ester can be prevented.
In the polycondensed ester, a diol residue is formed by the diol used for mixing.
The diol residue preferably includes at least one of an ethylene glycol residue, a 1,2-propanediol residue, and a 1,3-propanediol residue, and an ethylene glycol residue or a 1,2-propanediol residue It is more preferable that
Of the aliphatic diol residues, the ethylene glycol residue is preferably 20 mol% to 100 mol%, and more preferably 50 mol% to 100 mol%.

The terminal of the polycondensed ester of the present invention is not capped and remains a diol or carboxylic acid, or may be further reacted with a monocarboxylic acid or monoalcohol to carry out so-called terminal capping.
As monocarboxylic acids used for sealing, acetic acid, propionic acid, butanoic acid and the like are preferable, acetic acid or propionic acid is more preferable, and acetic acid is most preferable. As monoalcohols used for sealing, methanol, ethanol, propanol, isopropanol, butanol, isobutanol and the like are preferable, and methanol is most preferable. When the number of carbon atoms of the monocarboxylic acid used at the terminal of the polycondensed ester is 3 or less, the loss on heating of the compound does not increase, and no surface failure occurs.
More preferably, the end of the polycondensed ester of the present invention is not capped and remains a diol residue, or is more preferably capped with acetic acid or propionic acid.
Both ends of the polycondensed ester according to the present invention may be sealed or unsealed.
When both ends of the condensate are unsealed, the polycondensed ester is preferably a polyester polyol.
One aspect of the polycondensed ester according to the present invention is a polycondensed ester in which the aliphatic diol residue has 2.5 to 7.0 carbon atoms and both ends of the condensate are unblocked. Can do.
When both ends of the condensate are sealed, it is preferably sealed by reacting with a monocarboxylic acid. At this time, both ends of the polycondensed ester are monocarboxylic acid residues. In the present specification, a residue is a partial structure of a polycondensed ester and represents a partial structure having the characteristics of a monomer forming the polycondensed ester. For example, the monocarboxylic acid residue formed from monocarboxylic acid R—COOH is R—CO—. It is preferably an aliphatic monocarboxylic acid residue, more preferably an aliphatic monocarboxylic acid residue having 22 or less carbon atoms, and an aliphatic monocarboxylic acid residue having 3 or less carbon atoms. More preferably it is. In addition, an aliphatic monocarboxylic acid residue having 2 or more carbon atoms is preferable, and an aliphatic monocarboxylic acid residue having 2 carbon atoms is particularly preferable.
One aspect of the polycondensation ester according to the present invention is a polycondensation ester in which the aliphatic diol residue has a carbon number of greater than 2.5 and no greater than 7.0, and both ends of the condensate are monocarboxylic acid residues. Can be mentioned.
When the number of carbon atoms of the monocarboxylic acid residue at both ends of the polycondensed ester is 3 or less, the volatility is lowered, the weight loss due to heating of the polycondensed ester does not increase, and process contamination and surface failure occur. Can be reduced.
That is, the monocarboxylic acid used for sealing is preferably an aliphatic monocarboxylic acid. More preferably, the monocarboxylic acid is an aliphatic monocarboxylic acid having 2 to 22 carbon atoms, more preferably an aliphatic monocarboxylic acid having 2 to 3 carbon atoms, and an aliphatic monocarboxylic acid residue having 2 carbon atoms. Particularly preferred is a group.
For example, acetic acid, propionic acid, butanoic acid, benzoic acid and derivatives thereof are preferable, acetic acid or propionic acid is more preferable, and acetic acid is most preferable.
Two or more monocarboxylic acids used for sealing may be mixed.
Both ends of the polycondensed ester of the present invention are preferably sealed with acetic acid or propionic acid, and most preferably both ends become acetyl ester residues (sometimes referred to as acetyl residues) by acetic acid sealing.
When both ends are sealed, the state at normal temperature is unlikely to be in a solid form, the handling becomes good, and a cyclic olefin resin film excellent in humidity stability and durability can be obtained.

  Examples of the polycondensation ester according to the present invention include, but are not limited to, the following aliphatic high molecular weight plasticizers (PA) and aromatic polymer plasticizers (PB).

  Hereinafter, an aliphatic high molecular weight plasticizer (PA) having a number average molecular weight of 700 to 10,000 and having a repeating unit composed of an aliphatic dicarboxylic acid and an aliphatic diol, and optionally an aliphatic monocarboxylic acid or an aliphatic monoalcohol. Specific examples are described below, but the present invention is not limited thereto.

PA-1: Condensate composed of ethylene glycol / succinic acid (1/1 molar ratio) (number average molecular weight 1100)
PA-2: Condensate composed of 1,3-propanediol / glutaric acid (1/1 molar ratio) (number average molecular weight 1500)
PA-3: Condensate consisting of 1,3-propanediol / adipic acid (1/1 molar ratio) (number average molecular weight 900)
PA-4: Condensate (number average molecular weight 1500) consisting of 1,3-propanediol / ethylene glycol / adipic acid (1/1/2 molar ratio)

PA-5: Condensate (number average molecular weight 1400) consisting of 2-methyl-1,3-propanediol / adipic acid (1/1 molar ratio)
PA-6: Acetyl ester at both ends of a condensate composed of ethylene glycol / succinic acid / adipic acid (2/1/1 molar ratio) (number average molecular weight 1000)
PA-7: Condensate (number average molecular weight 1800) consisting of 1,4-cyclohexanediol / succinic acid (1/1 molar ratio)

PA-8: butyl esterified product (number average molecular weight 1200) at both ends of the condensate consisting of 1,3-propanediol / succinic acid (1/1 molar ratio)
PA-9: A cyclohexyl esterified product (number average molecular weight 1500) at both ends of a condensate composed of 1,3-propanediol / glutaric acid (1/1 molar ratio)
PA-10: Acetyl ester of both ends of a condensate composed of ethylene glycol / succinic acid (1/1 molar ratio) (number average molecular weight 3000)
PA-11: Isononyl esterified product (number average molecular weight 1500) at both ends of a condensate composed of 1,3-propanediol / ethylene glycol / adipic acid (1/1/2 molar ratio)

PA-12: Propyl esterified product (number average molecular weight 1300) at both ends of a condensate composed of 2-methyl-1,3-propanediol / adipic acid (1/1 molar ratio)
PA-13: Acetyl ester of both ends of a condensate composed of 2-methyl-1,3-propanediol / adipic acid (1/1 molar ratio) (number average molecular weight 1700)

PA-14: Isononyl esterified product (number average molecular weight 1500) at both ends of a condensate composed of 2-methyl-1,3-propanediol / adipic acid (1/1 molar ratio)
PA-15: butyl esterified product (number average molecular weight 1100) at both ends of a condensate consisting of 1,4-butanediol / adipic acid (1/1 molar ratio)
PA-16: Condensate (number average molecular weight 2800) composed of poly (average polymerization degree 5) propylene ether glycol / succinic acid (1/1 molar ratio)

PA-17: Condensate (number average molecular weight 2300) comprising poly (average polymerization degree 3) ethylene ether glycol / glutaric acid (1/1 molar ratio)
PA-18: Condensate (number average molecular weight 2200) composed of poly (average polymerization degree 4) propylene ether glycol / adipic acid (1/1 molar ratio)
PA-19: Polyester (average degree of polymerization 5) butyl esterified product (number average molecular weight 1900) of a condensate consisting of propylene ether glycol / succinic acid (1/1 molar ratio)

PA-20: poly (average polymerization degree 3) 2-ethylhexyl esterified product (number average molecular weight 2500) at both ends of a condensate composed of ethylene ether glycol / glutaric acid (1/1 molar ratio)
PA-21: Polyester (average polymerization degree 4) propylene ether glycol / adipic acid (1/1 molar ratio) condensate at both ends acetyl esterified product (number average molecular weight 1500)
PA-22: Propionyl esterified product (number average molecular weight 1900) at both ends of a condensate composed of poly (average polymerization degree 4) propylene ether glycol / phthalic acid (1/1 molar ratio)
PA-23: Condensate (number average molecular weight 1000) consisting of ethylene glycol / adipic acid (1/1 molar ratio)

Similarly, the aliphatic diol described in the above-mentioned aliphatic polymer plasticizer (PA) can be used for the aliphatic diol used in the aromatic high molecular weight plasticizer (PB), and the alkyl ether having 4 to 20 carbon atoms. Diols can be used as well.
Next, in the aromatic high molecular weight plasticizer (PB), an aromatic ring-containing diol can also be used as the diol. The preferred aromatic ring-containing diol is at least one diol selected from aromatic diols having 6 to 20 carbon atoms, such as bisphenol A, 1,2-hydroxybenzene, 1,3-dihydroxybenzene, 1, Examples include 4-dihydroxybenzene and benzene-1,4-dimethanol, and bisphenol A, 1,4-dihydroxybenzene, and benzene-1,4-dimethanol are preferable.

The aromatic polymer plasticizer (PB) has a number average molecular weight of 700 to 10,000 and has a repeating unit composed of at least one of an aromatic dicarboxylic acid and an aromatic diol.
Further, in the aromatic high molecular weight plasticizer (PB), it is also preferable to use an aliphatic monocarboxylic acid, an aliphatic monoalcohol, an aromatic ring-containing monocarboxylic acid or an aromatic ring-containing monoalcohol in some cases. In that case, for the aliphatic monocarboxylic acid and the aliphatic monoalcohol, the aliphatic monocarboxylic acid and the aliphatic monoalcohol described in the above-mentioned aliphatic polymer plasticizer (PA) can be used. Alkyl ether diols can be used as well.

  Alternatively, for the aromatic ring-containing monoalcohol, at least one selected from an aromatic ring-containing group having 6 to 20 carbon atoms, an aliphatic carbonyl group having 2 to 22 carbon atoms, and an aromatic carbonyl group having 7 to 20 carbon atoms. It is preferable to contain, for example, phenol, cresol, benzyl alcohol, phenylethanol, phenethyl alcohol, 1-naphthyl alcohol, etc., preferably benzyl alcohol and phenylethanol. The aromatic ring-containing monocarboxylic acid is at least selected from an aromatic ring-containing group having 6 to 20 carbon atoms, an aliphatic carbonyl group having 2 to 22 carbon atoms, and an aromatic carbonyl group having 7 to 20 carbon atoms. 1 type is preferable, for example, benzoic acid, p-tert-butylbenzoic acid, p-tert-amylbenzoic acid, orthotoluic acid, metatoluic acid, p-toluic acid, dimethylbenzoic acid, ethylbenzoic acid, n-propylbenzoic acid Aminobenzoic acid, acetoxybenzoic acid, phenylacetic acid, cinnamic acid and the like, preferably benzoic acid, phenylacetic acid and cinnamic acid. These can use 1 type (s) or 2 or more types, respectively.

  The synthesis of the polycondensed ester according to the present invention may be carried out by any of conventional methods such as a hot melt condensation method by a polyesterification reaction or transesterification reaction between a diol and a dicarboxylic acid, or an interfacial condensation method between these acid chlorides and glycols. This method can be easily synthesized. In addition, the polycondensed ester according to the present invention is described in detail in Koichi Murai, “Plasticizer Theory and Application” (Kokai Shobo Co., Ltd., first edition issued on March 1, 1973). In addition, Japanese Patent Laid-Open Nos. 05-155809, 05-155810, Japanese Patent Laid-Open Nos. 05-97073, 2006-259494, 07-330670, 2006-342227, 2007-003679. The materials described in each publication can also be used.

  The content of the polycondensed ester in the cyclic olefin resin film is preferably 5 to 40% by mass, more preferably 8 to 30% by mass with respect to the amount of the cyclic olefin resin. Most preferably.

The content of the raw material aliphatic diol, dicarboxylic acid ester or diol ester contained in the polycondensate of the present invention in the cyclic olefin resin film is preferably less than 1% by mass, more preferably less than 0.5% by mass. . Examples of the dicarboxylic acid ester include dimethyl phthalate, di (hydroxyethyl) phthalate, dimethyl terephthalate, di (hydroxyethyl) terephthalate, di (hydroxyethyl) adipate, and di (hydroxyethyl) succinate. Examples of the diol ester include ethylene diacetate and propylene diacetate.
The kind and ratio of each of the dicarboxylic acid residue, diol residue, and monocarboxylic acid residue contained in the polycondensation ester used in the present invention can be measured by a usual method using H-NMR. . Usually, deuterated chloroform can be used as a solvent.
The number average molecular weight of the polycondensed ester can be measured by a usual method using GPC (Gel Permeation Chromatography), and polystyrene can be usually used as a standard material.
For measurement of the hydroxyl value of the polycondensed ester, the acetic anhydride method described in Japanese Industrial Standard JIS K3342 (discontinued) can be applied. When the polycondensate is a polyester polyol, the hydroxyl value is preferably from 50 to 190, and more preferably from 50 to 130.

<Acrylic acid ester polymer>
The acrylic ester polymer is a structural unit obtained from an acrylic ester monomer. Examples of the acrylate monomer include, for example, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-). , Pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), heptyl acrylate (n-, i-), octyl acrylate (n-, i-), acrylic acid Nonyl (n-, i-), myristyl acrylate (n-, i-), acrylic acid (2-ethylhexyl), acrylic acid (ε-caprolactone), acrylic acid (2-hydroxyethyl), acrylic acid (2- Hydroxypropyl), acrylic acid (3-hydroxypropyl), acrylic acid (4-hydroxybutyl), acrylic acid (2-hydroxybutyl), acrylic acid (2-methoxyethyl), acrylic acid Phosphoric acid (2-ethoxyethyl) phenyl acrylate, phenyl methacrylate, acrylic acid (2 or 4-chlorophenyl), methacrylic acid (2 or 4-chlorophenyl), acrylic acid (2 or 3 or 4-ethoxycarbonylphenyl), Methacrylic acid (2 or 3 or 4-ethoxycarbonylphenyl), acrylic acid (o or m or p-tolyl), methacrylic acid (o or m or p-tolyl), benzyl acrylate, benzyl methacrylate, phenethyl acrylate, Phenethyl methacrylate, acrylic acid (2-naphthyl), cyclohexyl acrylate, cyclohexyl methacrylate, acrylic acid (4-methylcyclohexyl), methacrylic acid (4-methylcyclohexyl), acrylic acid (4-ethylcyclohexyl), methacrylic acid ( 4-ethylsic (Rohexyl) and the like, or those obtained by replacing the acrylic ester with a methacrylic ester, but the present invention is not limited to these specific examples. Two or more of these monomers may be used as a copolymerization component. Of these, methyl acrylate, ethyl acrylate, propyl acrylate (i-, n-), butyl acrylate (n-, i-, s-, t-), pentyl acrylate (n-, i-, s-), hexyl acrylate (n-, i-), or those obtained by replacing the above acrylate esters with methacrylate esters are preferred.

<Plasticizers other than polycondensation esters and acrylic esters>
As the plasticizer used in the present invention, many compounds known as plasticizers for cyclic olefin resins can also be used effectively. As the plasticizer other than the polycondensed ester, compounds such as phosphate ester, carboxylic acid ester, and sugar ester are used. Examples of phosphate esters include triphenyl phosphate (TPP) and tricresyl phosphate (TCP). Representative examples of the carboxylic acid ester include phthalic acid esters and citric acid esters. Examples of phthalic acid esters include dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP), diphenyl phthalate (DPP) and diethyl hexyl phthalate (DEHP). Examples of citrate esters include triethyl O-acetylcitrate (OACTE) and tributyl O-acetylcitrate (OACTB). Examples of other carboxylic acid esters include butyl oleate, methylacetyl ricinoleate, dibutyl sebacate, and various trimellitic acid esters. Phthalate plasticizers (DMP, DEP, DBP, DOP, DPP, DEHP) are preferably used. DEP and DPP are particularly preferred.

(Retardation expression agent)
The film of the present invention may contain a retardation enhancer in order to express the Rth retardation value, but the content of the retardation enhancer is 8% by mass or less based on the cyclic olefin resin. Is preferable and it is preferable that it is 1 mass% or more. Although there is no restriction | limiting in particular as said retardation expression agent, What consists of a rod-shaped or a disk shaped compound can be mentioned. As the rod-like or discotic compound, a compound having at least two aromatic rings can be preferably used as a retardation developer.
The addition amount of the retardation enhancer composed of the rod-like compound is preferably 8 parts by mass or less, more preferably 5 parts by mass or less, with respect to 100 parts by mass of the cyclic olefin resin component. The discotic compound contained in the retardation enhancer is preferably 8 parts by mass or less, more preferably 5 parts by mass or less, and more preferably 4 parts by mass or less with respect to 100 parts by mass of the cyclic olefin resin. It is particularly preferred that
Since the discotic compound is superior to the rod-shaped compound in Rth retardation expression, it is preferably used when a particularly large Rth retardation is required. Two or more retardation developers may be used in combination.
The retardation developer preferably has a maximum absorption in the wavelength region of 250 to 400 nm, and preferably has substantially no absorption in the visible region.

(Discotic compound)
The discotic compound will be described. As the discotic compound, a compound having at least two aromatic rings can be used.
In the present specification, the “aromatic ring” includes an aromatic hetero ring in addition to an aromatic hydrocarbon ring.
The aromatic hydrocarbon ring is particularly preferably a 6-membered ring (that is, a benzene ring).
The aromatic heterocycle is generally an unsaturated heterocycle. The aromatic heterocycle is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring. Aromatic heterocycles generally have the most double bonds. As the hetero atom, a nitrogen atom, an oxygen atom and a sulfur atom are preferable, and a nitrogen atom is particularly preferable. Examples of aromatic heterocycles include furan ring, thiophene ring, pyrrole ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, pyrazole ring, furazane ring, triazole ring, pyran ring, pyridine ring , Pyridazine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring.
As the aromatic ring, a benzene ring, a condensed benzene ring, and biphenyls are preferable. In particular, a 1,3,5-triazine ring is preferably used. Specifically, for example, compounds disclosed in JP-A No. 2001-166144 are preferably used.

The number of carbon atoms of the aromatic ring in the retardation enhancer is preferably 2-20, more preferably 2-12, still more preferably 2-8, and 2-6. Most preferred.
The bonding relationship between two aromatic rings can be classified into (a) when forming a condensed ring, (b) when directly connecting with a single bond, and (c) when connecting via a linking group (for aromatic rings). , Spiro bonds cannot be formed). The connection relationship may be any of (a) to (c).

  Examples of the condensed ring (a condensed ring of two or more aromatic rings) include an indene ring, a naphthalene ring, an azulene ring, a fluorene ring, a phenanthrene ring, an anthracene ring, an acenaphthylene ring, a biphenylene ring, a naphthacene ring, Pyrene ring, indole ring, isoindole ring, benzofuran ring, benzothiophene ring, indolizine ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring, purine ring, indazole ring, chromene ring, quinoline ring, isoquinoline Ring, quinolidine ring, quinazoline ring, cinnoline ring, quinoxaline ring, phthalazine ring, pteridine ring, carbazole ring, acridine ring, phenanthridine ring, xanthene ring, phenazine ring, phenothiazine ring, phenoxathiin ring, phenoxazine ring and thiantole Ring is included. Naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferred.

  The single bond (b) is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded by two or more single bonds to form an aliphatic ring or a non-aromatic heterocyclic ring between the two aromatic rings.

The linking group in (c) is also preferably bonded to carbon atoms of two aromatic rings. The linking group is preferably an alkylene group, an alkenylene group, an alkynylene group, —CO—, —O—, —NH—, —S—, or a combination thereof. Examples of linking groups composed of combinations are shown below. In addition, the relationship between the left and right in the following examples of the linking group may be reversed.
c1: -CO-O-
c2: —CO—NH—
c3: -alkylene-O-
c4: —NH—CO—NH—
c5: —NH—CO—O—
c6: —O—CO—O—
c7: -O-alkylene-O-
c8: -CO-alkenylene-
c9: -CO-alkenylene-NH-
c10: -CO-alkenylene-O-
c11: -alkylene-CO-O-alkylene-O-CO-alkylene-
c12: -O-alkylene-CO-O-alkylene-O-CO-alkylene-O-
c13: -O-CO-alkylene-CO-O-
c14: -NH-CO-alkenylene-
c15: -O-CO-alkenylene-

The aromatic ring and the linking group may have a substituent.
Examples of substituents include halogen atoms (F, Cl, Br, I), hydroxyl groups, carboxyl groups, cyano groups, amino groups, nitro groups, sulfo groups, carbamoyl groups, sulfamoyl groups, ureido groups, alkyl groups, alkenyls. Group, alkynyl group, aliphatic acyl group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamido group, aliphatic substituted amino group An aliphatic substituted carbamoyl group, an aliphatic substituted sulfamoyl group, an aliphatic substituted ureido group, and a non-aromatic heterocyclic group.

It is preferable that the alkyl group has 1 to 8 carbon atoms. A chain alkyl group is preferable to a cyclic alkyl group, and a linear alkyl group is particularly preferable. The alkyl group may further have a substituent (for example, a hydroxy group, a carboxy group, an alkoxy group, an alkyl-substituted amino group). Examples of alkyl groups (including substituted alkyl groups) include methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl and 2-methoxyethyl. Each group of a diethylaminoethyl group is included.
The alkenyl group preferably has 2 to 8 carbon atoms. A chain alkenyl group is preferable to a cyclic alkenyl group, and a linear alkenyl group is particularly preferable. The alkenyl group may further have a substituent. Examples of the alkenyl group include a vinyl group, an allyl group, and a 1-hexenyl group.
The alkynyl group preferably has 2 to 8 carbon atoms. A chain alkynyl group is preferable to a cyclic alkynyl group, and a linear alkynyl group is particularly preferable. The alkynyl group may further have a substituent. Examples of the alkynyl group include ethynyl group, 1-butynyl group and 1-hexynyl group.

The number of carbon atoms in the aliphatic acyl group is preferably 1-10. Examples of the aliphatic acyl group include an acetyl group, a propanoyl group, and a butanoyl group.
The number of carbon atoms in the aliphatic acyloxy group is preferably 1-10. Examples of the aliphatic acyloxy group include an acetoxy group.
The number of carbon atoms of the alkoxy group is preferably 1-8. The alkoxy group may further have a substituent (for example, an alkoxy group). Examples of the alkoxy group (including a substituted alkoxy group) include a methoxy group, an ethoxy group, a butoxy group, and a methoxyethoxy group.
The number of carbon atoms of the alkoxycarbonyl group is preferably 2-10. Examples of the alkoxycarbonyl group include a methoxycarbonyl group and an ethoxycarbonyl group.
The number of carbon atoms of the alkoxycarbonylamino group is preferably 2-10. Examples of the alkoxycarbonylamino group include a methoxycarbonylamino group and an ethoxycarbonylamino group.

The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include a methylthio group, an ethylthio group, and an octylthio group.
The alkylsulfonyl group preferably has 1 to 8 carbon atoms. Examples of the alkylsulfonyl group include a methanesulfonyl group and an ethanesulfonyl group.
The number of carbon atoms in the aliphatic amide group is preferably 1-10. Examples of the aliphatic amide group include acetamide.
The number of carbon atoms of the aliphatic sulfonamide group is preferably 1-8. Examples of the aliphatic sulfonamide group include a methane sulfonamide group, a butane sulfonamide group, and an n-octane sulfonamide group.
The number of carbon atoms of the aliphatic substituted amino group is preferably 1-10. Examples of the aliphatic substituted amino group include a dimethylamino group, a diethylamino group, and a 2-carboxyethylamino group.
The number of carbon atoms in the aliphatic substituted carbamoyl group is preferably 2-10. Examples of the aliphatic substituted carbamoyl group include a methylcarbamoyl group and a diethylcarbamoyl group.
The number of carbon atoms in the aliphatic substituted sulfamoyl group is preferably 1-8. Examples of the aliphatic substituted sulfamoyl group include a methylsulfamoyl group and a diethylsulfamoyl group.
The number of carbon atoms in the aliphatic substituted ureido group is preferably 2-10. Examples of the aliphatic substituted ureido group include a methylureido group.
Examples of the non-aromatic heterocyclic group include a piperidino group and a morpholino group.
The molecular weight of the retardation developer is preferably 300 to 800.

  As the discotic compound, a triazine compound represented by the following general formula (I) is preferably used.

In the above general formula (I):
R ²⁰¹ each independently represents an aromatic ring or a heterocyclic ring having a substituent in at least one of the ortho position, meta position and para position.
X ²⁰¹ independently represents a single bond or a NR ²⁰² - represents a. Here, each R ²⁰² independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, an alkenyl group, an aryl group, or a heterocyclic group.

The aromatic ring represented by ^R201 is preferably phenyl or naphthyl, and particularly preferably phenyl. The aromatic ring R ²⁰¹ represents may have at least one substituent at any substitutable position. Examples of the substituent include halogen atom, hydroxyl group, cyano group, nitro group, carboxyl group, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, Alkenyloxycarbonyl group, aryloxycarbonyl group, sulfamoyl group, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamide group, carbamoyl, alkyl-substituted carbamoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide Groups, alkylthio groups, alkenylthio groups, arylthio groups and acyl groups.

The heterocyclic group represented by ^R201 preferably has aromaticity. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, a 6-membered ring or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably a nitrogen atom, a sulfur atom or an oxygen atom, and particularly preferably a nitrogen atom. As the heterocyclic ring having aromaticity, a pyridine ring (2-pyridyl or 4-pyridyl as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety.
When X ²⁰¹ is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms. Further, the heterocyclic group may have a hetero atom other than the nitrogen atom (for example, O, S). Examples of heterocyclic groups having free valences on nitrogen atoms are shown below. Here, -C ₄ H ₉ ⁿ represents a n-C ₄ H _9.

The alkyl group represented by R ²⁰² may be a cyclic alkyl group or a chain alkyl group, but a chain alkyl group is preferable, and a linear alkyl group is more preferable than a branched chain alkyl group. preferable. The number of carbon atoms in the alkyl group is preferably 1-30, more preferably 1-20, still more preferably 1-10, still more preferably 1-8, and 1-6. Most preferred. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (for example, methoxy group, ethoxy group) and an acyloxy group (for example, acryloyloxy group, methacryloyloxy group).

The alkenyl group represented by R ²⁰² may be a cyclic alkenyl group or a chain alkenyl group, but is preferably a chain alkenyl group and is more preferably a linear alkenyl group than a branched chain alkenyl group. More preferably it represents a group. The number of carbon atoms in the alkenyl group is preferably 2 to 30, more preferably 2 to 20, still more preferably 2 to 10, still more preferably 2 to 8, 6 is most preferred. The alkenyl group may have a substituent. Examples of the substituent are the same as those of the alkyl group described above.
The aromatic ring group and heterocyclic group represented by R ²⁰² are the same as the aromatic ring and heterocyclic ring represented by R ²⁰¹ , and the preferred range is also the same. The aromatic ring group and the heterocyclic group may further have a substituent, and examples of the substituent are the same as those of the aromatic ring and heterocyclic ring of ^R201 .

  The compound represented by the general formula (I) can be synthesized by a known method such as the method described in JP-A-2003-344655. Details of the retardation enhancer are described on page 49 of published technical bulletin 2001-1745.

  As the rod-like compound, for example, a compound represented by the following general formula (Ia), (IIa) or (IIIa) is preferable.

(In the formula, R ¹ represents an alkyl group having 1 to 10 carbon atoms which may have an ether bond, or an alkoxy group having 1 to 10 carbon atoms, and A ¹ represents trans 1,4-cyclohexylene or 1, 4 represents phenylene.)

(In the formula, R ² represents an alkyl group having 1 to 10 carbon atoms which may have an ether bond, or an alkoxy group having 1 to 10 carbon atoms, and A ² represents trans 1,4-cyclohexylene or 1, 4 represents phenylene, and X ¹ represents a cyano group, an alkyl group having 1 to 10 carbon atoms which may have an ether bond, or an alkoxy group having 1 to 10 carbon atoms.)

(In the formula, R ³ represents an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms which may have an ether bond, and A ³ represents trans 1,4-cyclohexylene or 1, 4 represents phenylene, and X ² represents a cyano group, an alkyl group having 1 to 10 carbon atoms which may have an ether bond, or an alkoxy group having 1 to 10 carbon atoms.)

In the compound represented by the general formula (Ia), R ¹ is an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms which may have an ether bond. Examples of the alkyl group having 1 to 10 carbon atoms which may have an ether bond include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, isoamyl, tert-amyl, Hexyl, cyclohexyl, heptyl, isoheptyl, tertiary heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl, nonyl, isononyl, decyl, methoxymethyl, methoxyethyl and the like, and alkoxy having 1 to 10 carbon atoms Examples of the group include methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like. R ¹ is particularly preferably a linear alkyl group having 2 to 7 carbon atoms from the viewpoint of viscosity, and specifically, ethyl, propyl, butyl, pentyl, and heptyl are preferable. A ¹ is trans-1,4-cyclohexylene or 1,4-phenylene.

In the compound represented by the general formula (IIa), R ² is an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms which may have an ether bond. Examples of the alkyl group having 1 to 10 carbon atoms which may have an ether bond include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, isoamyl, tert-amyl, Hexyl, cyclohexyl, heptyl, isoheptyl, tertiary heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl, nonyl, isononyl, decyl, methoxymethyl, methoxyethyl and the like, and alkoxy having 1 to 10 carbon atoms Examples of the group include methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like. R ² is particularly preferably a linear alkyl group having 2 to 7 carbon atoms from the viewpoint of viscosity), and specifically, propyl and pentyl are preferable.

X ¹ is a cyano group, an alkyl group having 1 to 10 carbon atoms which may have an ether bond, or an alkoxy group having 1 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms which may have an ether bond include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, isoamyl, tert-amyl, Hexyl, cyclohexyl, heptyl, isoheptyl, tertiary heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl, nonyl, isononyl, decyl, methoxymethyl, methoxyethyl and the like, and alkoxy having 1 to 10 carbon atoms Examples of the group include methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like. X ¹ is preferably an alkyl group having a cyano group from the viewpoint of liquid crystallinity and refractive index anisotropy, and an alkyl group or an ether group from the viewpoint of low viscosity.

A ² is trans-1,4-cyclohexylene or 1,4-phenylene.

In the compound represented by the general formula (IIIa), R ³ is an alkyl group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, which may have an ether bond. Examples of the alkyl group having 1 to 10 carbon atoms which may have an ether bond include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, isoamyl, tert-amyl, Hexyl, cyclohexyl, heptyl, isoheptyl, tertiary heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl, nonyl, isononyl, decyl, methoxymethyl, methoxyethyl and the like, and alkoxy having 1 to 10 carbon atoms Examples of the group include methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like. R ³ is particularly preferably a linear alkyl group having 2 to 7 carbon atoms from the viewpoint of viscosity, and specifically, ethyl, propyl, pentyl and heptyl are preferable.

X ² is a cyano group, an alkyl group having 1 to 10 carbon atoms which may have an ether bond, or an alkoxy group having 1 to 10 carbon atoms. Examples of the alkyl group having 1 to 10 carbon atoms which may have an ether bond include methyl, ethyl, propyl, isopropyl, butyl, sec-butyl, tert-butyl, isobutyl, amyl, isoamyl, tert-amyl, hexyl, cyclohexyl , Heptyl, isoheptyl, tertiary heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl, nonyl, isononyl, decyl, methoxymethyl, methoxyethyl, etc., and examples of the alkoxy group having 1 to 10 carbon atoms include Methoxy, ethoxy, propoxy, butoxy, pentyloxy, heptyloxy, octyloxy, nonyloxy, decyloxy and the like. X ² is preferably a cyano group, and is preferably an alkyl group or an alkyl group having an ether bond, particularly preferably a linear alkyl group, from the viewpoint of low viscosity and good storage stability at low temperatures.

  The specific structure of the compound represented by any one of the general formulas (Ia) to (IIIa) can be the compound described in JP 2010-159361 A, but is not limited thereto.

  As the retardation developer of the present invention, a polymer additive can be used as in the case of the low molecular compound. Here, the polymer used as the polycondensed ester in the present invention may also serve as a retardation developer. As the polymeric retardation developer that is also a polycondensed ester, the aromatic polyester polymer and a copolymer of the aromatic polyester polymer and other resins are preferable.

(Retardation reducing agent)
In the present invention, as one of the retardation control means, a phosphoric acid ester compound or a known compound as a cyclic olefin resin film additive can be widely used as a retardation reducing agent.

  The polymer retardation reducing agent is selected from phosphoric acid-based polyester polymers, styrene polymers, acrylic polymers, and copolymers thereof, and acrylic polymers and styrene polymers are preferred. Moreover, it is preferable that at least one polymer having negative intrinsic birefringence, such as a styrene polymer and an acrylic polymer, is included.

  Examples of the low molecular weight retardation reducing agent include the following. These may be solid or oily. That is, the melting point and boiling point are not particularly limited. For example, mixing of an ultraviolet absorbing material at 20 ° C. or lower and 20 ° C. or higher, and a mixture of deterioration preventing agents are also possible. Furthermore, infrared absorbing dyes are described, for example, in JP-A-2001-194522. Moreover, the addition time may be added at any time in the cyclic olefin-based resin solution (dope) preparation step, but it may be added at the final preparation step of the dope preparation step by adding a preparation step. . Furthermore, the amount of each material added is not particularly limited as long as the function is manifested.

  Although it does not specifically limit as a low molecular weight retardation reducing agent, The details are described in Unexamined-Japanese-Patent No. 2007-272177 [0066]-[0085].

The compound described as the general formula (1) in [0066] to [0085] of JP-A-2007-272177 can be prepared by the following method.
The compound of the general formula (1) of the publication can be obtained by a condensation reaction between a sulfonyl chloride derivative and an amine derivative.

  JP, 2007-272177, A The compound of general formula (2) is a dehydration condensation reaction of carboxylic acids and amines using a condensing agent (for example, dicyclohexylcarbodiimide (DCC) etc.), or a carboxylic acid chloride derivative, It can be obtained by a substitution reaction with an amine derivative.

(Deterioration inhibitor)
In the present invention, a known deterioration (oxidation) inhibitor such as 2,6-di-tert-butyl-4-methylphenol, 4,4′-thiobis- (6-tert-butyl-) is added to the cyclic olefin resin solution. 3-methylphenol), 1,1′-bis (4-hydroxyphenyl) cyclohexane, 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, penta A phenolic or hydroquinone antioxidant such as erythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] can be added. Further, tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-tert-butylphenyl) phosphite, bis (2,6-di-tert) It is preferable to use a phosphorus-based antioxidant such as -butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-di-tert-butylphenyl) pentaerythritol diphosphite. The addition amount of the deterioration inhibitor is 0.05 to 5.0 parts by mass with respect to 100 parts by mass of the cyclic olefin resin.

(UV absorber)
In the present invention, an ultraviolet absorber is preferably used for the cyclic olefin-based resin solution from the viewpoint of preventing deterioration of a polarizing plate or liquid crystal. As the ultraviolet absorber, those excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and having little absorption of visible light having a wavelength of 400 nm or more are preferably used from the viewpoint of good liquid crystal display properties. Specific examples of ultraviolet absorbers preferably used in the present invention include, for example, hindered phenol compounds, hydroxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds Etc. Examples of hindered phenol compounds include 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]. N, N′-hexamethylenebis (3,5-di-tert-butyl-4-hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert) -Butyl-4-hydroxybenzyl) benzene, tris- (3,5-di-tert-butyl-4-hydroxybenzyl) -isocyanurate and the like. Examples of benzotriazole compounds include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2,2-methylenebis (4- (1,1,3,3-tetramethylbutyl) -6 (2H-benzotriazol-2-yl) phenol), (2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5-di-tert-butylanilino) -1,3,5- Triazine, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate], N, N′-hexamethylenebis (3,5-di-tert-butyl-4- Hydroxy-hydrocinnamide), 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 2 (2′-hydroxy-3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, (2 (2′-hydroxy-3 ′, 5′-di-tert-amylphenyl) -5 -Chlorobenzotriazole, 2,6-di-tert-butyl-p-cresol, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and the like. The addition amount of these ultraviolet light inhibitors is preferably 1 ppm to 1.0%, more preferably 10 to 1000 ppm in terms of mass ratio in the whole cellulose acylate film.

(Matting agent)
The film of the present invention preferably contains a matting agent from the viewpoint of film slipperiness and stable production. The matting agent may be an inorganic compound matting agent or an organic compound matting agent.
Specific examples of the inorganic compound matting agent include silicon-containing inorganic compounds (for example, silicon dioxide, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, etc.), titanium oxide, and zinc oxide. , Aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, tin oxide / antimony, calcium carbonate, talc, clay, calcined kaolin, calcium phosphate, etc., more preferably silicon-containing inorganic compounds and oxides Although it is zirconium, since the turbidity of a cellulose acylate film can be reduced, silicon dioxide is particularly preferably used. As the silicon dioxide fine particles, for example, commercially available products having trade names such as Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600 (manufactured by Nippon Aerosil Co., Ltd.) can be used. As the zirconium oxide fine particles, for example, those commercially available under trade names such as Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.
Preferable specific examples of the organic compound matting agent include, for example, polymers such as silicone resin, fluorine resin and acrylic resin, and among them, silicone resin is preferably used. Of the silicone resins, those having a three-dimensional network structure are particularly preferable. A commercial product having a trade name can be used.

  When these matting agents are added to the cyclic olefin resin solution, the method is not particularly limited, and any method can be used as long as a desired cyclic olefin resin solution can be obtained. For example, an additive may be included at the stage of mixing the cyclic olefin resin and the solvent, or the additive may be added after preparing a mixed solution with the cyclic olefin resin and the solvent. Further, it may be added and mixed immediately before casting the dope, which is a so-called immediately preceding addition method, and the mixing is used by installing screw-type kneading online. Specifically, a static mixer such as an in-line mixer is preferable, and the in-line mixer is, for example, a static mixer SWJ (Toray static type in-pipe mixer Hi-Mixer) (manufactured by Toray Engineering). Is preferred. In addition, regarding in-line addition, in order to eliminate concentration unevenness, particle aggregation, etc., Japanese Patent Application Laid-Open No. 2003-053752 mixed additive liquids having different compositions into the main raw material dope in the method for producing a cyclic olefin resin film. An invention is described in which the distance L between the leading end of the additive nozzle and the starting end portion of the in-line mixer is 5 times or less the inner diameter d of the main raw material pipe, thereby eliminating concentration unevenness and aggregation of matte particles. As a more preferable embodiment, the distance (L) between the tip opening of the additive solution supply nozzle having a composition different from that of the main raw material dope and the start end of the in-line mixer is 10 times or less the inner diameter (d) of the supply nozzle tip opening. The in-line mixer is a static non-stirring type in-tube mixer or a dynamic stirring type in-tube mixer. More specifically, it is disclosed that the flow rate ratio of the cellulose acylate film main raw material dope / in-line additive solution is 10/1 to 500/1, preferably 50/1 to 200/1. Furthermore, the additive is also added to Japanese Patent Application Laid-Open No. 2003-014933 of the invention aiming at a retardation film with little additive bleed-out, no delamination phenomenon, excellent slipperiness and excellent transparency. As a method to do this, it may be added to the melting pot, or a solution in which additives or additives are dissolved or dispersed between the melting pot and the co-casting die may be added to the dope being fed. However, in the latter case, it is described that it is preferable to provide a mixing means such as a static mixer in order to improve the mixing property.

(Organic acid)
The film of the present invention preferably contains an organic acid represented by the following general formula (6).
General formula (6)
X−L− (R ¹ ) _n
(In the formula, X represents an acidic group having an acid dissociation constant of 5.5 or less, L represents a single bond or a divalent or higher valent linking group, R ¹ represents an alkyl group having 6 to 30 carbon atoms, and 6 to 6 carbon atoms. 30 represents an alkenyl group, an alkynyl group having 6 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a heterocyclic group having 6 to 30 carbon atoms, and may further have a substituent, where n is L. In the case of a single bond, it is 1, and in the case where L is a divalent or higher linking group, it is (the valence of L-1).

In the organic acid represented by the general formula (6), the releasability from the solution casting equipment (metal support when the dope is poured) can be improved by the X portion which is an acidic group.
Furthermore, the X portion that is an acidic group adheres to the metal surface of the support, and the R ¹ portion that is a hydrophobic group having a specific structure blocks the metal surface of the support from an oxidizing agent such as oxygen, Compared with an organic acid having a hydrophobic group outside the range of R ¹ , corrosion of the metal can be prevented.
Hereinafter, the peeling accelerator which can be used for the film of the present invention will be described.

In general formula (6), X represents an acid having an acid dissociation constant of 5.5 or less, and is preferably a carboxyl group, a sulfonic acid group, a sulfinic acid group, a phosphoric acid group, a sulfonic imide group, or an ascorbic acid group, A sulfonic acid group is further preferred, and a carboxyl group is most preferred. In addition, when X represents an ascorbic acid group, it is preferable that the hydrogen atom of the 5th-position and the 6-position is removed from the hydrogen atom of ascorbic acid and linked to L.
In this specification, as an acid dissociation constant, the value described in Chemical Handbook, published by Maruzen Co., Ltd. is adopted.

In general formula (6), R ¹ is a hydrogen atom, an alkyl group having 6 to 30 carbon atoms (which may have a substituent), an alkenyl group (which may have a substituent), an alkynyl group (a substituent). ), An aryl group (which may have a substituent), and a heterocyclic group (which may have a substituent). As substituents, halogen atom, aryl group, heterocyclic group, alkoxyl group, aryloxy group, alkylthio group, arylthio group, acyl group, hydroxyl group, acyloxy group, amino group, alkoxycarbonyl group, acylamino group, oxycarbonyl group, carbamoyl Group, sulfonyl group, sulfamoyl group, sulfonamide group, sulfolyl group, carboxyl group and the like.
R ¹ is more preferably an alkyl group having 8 to 24 carbon atoms, an alkenyl group, or an alkynyl group, and most preferably a linear alkyl group having 10 to 24 carbon atoms or an alkenyl group.

L in the general formula (6) is a single bond, or a divalent or higher linking group obtained by combining two or more linking groups obtained from the following unit group or two or more units selected from the following unit group. Preferably there is. Unit: —O—, —CO—, —N (—R ² ) — (wherein R ² is an alkyl group having 1 to 5 carbon atoms), —CH═CH—, —CH (OH) —, —CH ₂ —. , -SO ₂ -,

L in the general formula (6) is a partial structure of a single bond, a linking group derived from an ester group (—COO—, —OCO—), or a linking group derived from an amide group (—CONR ² —, —NR ² CO—). It is particularly preferable to have
In addition, L may further have a substituent, and the substituent is not particularly limited, and examples thereof include the substituent that R ¹ may have. Among them, —OH group Is preferred.
Among these, L is more preferably a linking group containing a glycerin-derived group.

Specifically, L preferably has the following structure. However, in the following, p, q, and r each represents an integer of 1 to 40, preferably 1 to 20, more preferably 1 to 10, and particularly preferably 1 to 6. Further, q is more preferably 2-4.
_{- (CH 2) p -CO-} O- (CH 2) q -O-;
_{- (CH 2) p -CO-} O- (CH 2) q - (CH (OH)) - (CH 2) r -O-;
_{- (CH 2) p -CO-} O- (CH 2) q - (CH (OCO-R 3)) - (CH 2) r -O-;
_{- (CH 2) p -CO-} O- (CH 2) q - (CH (OH)) - (CH 2) r -O-CO-;
_{- (CH 2) p -CO-} O- (CH 2) q - (CH (OCO-R 3)) - (CH 2) r -O-CO-.

Incidentally, R ³ contained in the above specific example of L is the same as defined in the R ¹ in the general formula (6). _{That, - (CH 2) p -CO} -O- (CH 2) q - (CH (OCO-R 3)) - (CH 2) R 3 in the connection group that _r -O- is for convenience described in the interior of the L The linking group L means a portion excluding R ³ . That is, in this case, L is trivalent. When represented by the general formula (6), XL- (R ¹ ) ₂ , wherein L is — (CH ₂ ) _p —CO—O— (CH ₂ ) _q — (CH (OCO —)) — (CH ₂ ) represents _r— O—], that is, the linking group L at this time is a trivalent linking group.
L and X are preferably bonded by an ester bond or an amide bond, and more preferably bonded by an ester bond. Further, X preferably has no ester bond or amide bond.
L and R ¹ are preferably bonded by an ester bond, an ether bond or an amide bond, more preferably bonded by an ester bond or an amide bond, and particularly preferably bonded by an ester bond. . R ¹ preferably has no ester bond, ether bond or amide bond.

Preferred specific examples of the organic acid represented by the general formula (6) are listed below.
"fatty acid"
Myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, ricinolenic acid, undecanoic acid.
《Alkyl sulfate》
Myristyl sulfate, cetyl sulfate, oleyl sulfate.
《Alkylbenzene sulfonic acid》
Dodecylbenzenesulfonic acid, pentadecylbenzenesulfonic acid.
《Alkyl naphthalene sulfonic acid》
Sesquibutyl naphthalene sulfonic acid, diisobutyl naphthalene sulfonic acid.
《Dialkylsulfosuccinic acid》
Dioctylsulfosuccinic acid, dihexylsulfosuccinic acid, dicyclohexylsuccinic acid, diamylsulfosuccinic acid, ditridecylcyclosuccinic acid.

《Partial derivative of polyvalent organic acid》
The organic acid represented by the general formula (6) is preferably a partial derivative of a polyvalent organic acid. In the present specification, a partial derivative of a polyvalent organic acid has a structure in which one molecule of a fatty acid and one polyvalent organic acid are ester-bonded to one molecule of a polyhydric alcohol. A compound having at least one acidic group. In the present specification, the fatty acid means an aliphatic monocarboxylic acid. That is, the fatty acids in the present specification are not limited to so-called higher aliphatics, and also include lower fatty acids having 12 or less carbon atoms such as acetic acid and propionic acid.
The partial derivative of the polyvalent organic acid is preferably a partial derivative of a polyvalent carboxylic acid. That is, the organic acid represented by the general formula (6) has a structure in which one molecule of a fatty acid and one molecule of a polyvalent carboxylic acid are ester-bonded to one molecule of a polyhydric alcohol. It is preferable to have at least one substituted carboxyl group. Although it does not specifically limit as polyvalent carboxylic acid used for the partial derivative of the said polyvalent carboxylic acid, For example, a succinic acid, a citric acid, tartaric acid, diacetyl tartaric acid, malic acid, and adipic acid are preferable.

  Examples of the polyhydric alcohol used in the partial derivative of the polyvalent organic acid include adonitol, arabitol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butanediol, 1,4-butanediol, dibutylene glycol, 1,2,4-butanetriol, 1,5-pentanediol, 1,6-hexanediol, hexanetriol, galactitol, mannitol, 3-methylpentane-1,3 , 5-triol, pinacol, sorbitol, trimethylolpropane, trimethylolethane, xylitol, glycerin and the like. Among them, glycerin is preferable, and the organic acid represented by the general formula (6) is preferably a so-called organic acid glyceride.

As the organic acid represented by the general formula (6), an organic acid glyceride in which the acidic group X of the organic acid is bonded to the hydrophobic part R ¹ through a linking group L containing a group derived from glycerin ( Glycerin fatty acid organic acid ester) is preferred. Here, the organic acid glyceride in the present specification means that one or two of the three hydroxyl groups of glycerin form an ester bond with a fatty acid, and one or two of the remaining hydroxyl groups are polyvalent. It refers to a compound having an ester bond with an organic acid and a structure having an acidic group derived from the polyvalent organic acid.
Among these, organic acid monoglycerides or organic acid diglycerides are more preferable, and organic acid monoglycerides are more preferable. In the present specification, organic acid monoglyceride means that one of three hydroxyl groups of glycerin forms an ester bond with a fatty acid, and one or two of the remaining hydroxyl groups form an ester bond with a polyvalent organic acid. It means a compound having a structure having an acidic group derived from the polyvalent organic acid. In the present specification, organic acid diglyceride means that two of the three hydroxyl groups of glycerin form an ester bond with a fatty acid, and the remaining one hydroxyl group forms an ester bond with a polyvalent organic acid, A compound having a structure having an acidic group derived from a polyvalent organic acid.

  Among the organic acid monoglycerides, one of the three hydroxyl groups of glycerin forms an ester bond with a fatty acid, one of the remaining hydroxyl groups is an unsubstituted hydroxyl group, and the remaining one hydroxyl group is polyvalent. It is particularly preferable that the compound has an ester bond with an organic acid and has a structure having an acidic group derived from the polyvalent organic acid. The hydroxyl group that is ester-bonded to the fatty acid of the organic acid monoglyceride is preferably an asymmetric position (so-called α-monoglyceride position), and the hydroxyl group that is ester-bonded to the polyvalent organic acid of the organic acid monoglyceride is also asymmetric It is preferable that it is the position (position of what is called alpha monoglyceride). That is, among the organic acid monoglycerides, a carbon atom directly bonded to a hydroxyl group having an unsubstituted hydroxyl group and ester-bonded to a fatty acid, and a carbon atom directly bonded to a hydroxyl group ester-linked to a polyvalent organic acid, It is preferable that it is a compound of the structure where is not adjacent.

  Among the organic acid monoglycerides, monoglycerides of polyvalent carboxylic acids are particularly preferable. The monoglyceride of the polyvalent carboxylic acid refers to an organic acid in which at least one of the polyvalent carboxylic acids has an unsubstituted carboxyl group and the other carboxyl groups are substituted with the monoglyceride. That is, a carboxyl group-containing organic acid monoglyceride in which one molecule of fatty acid and one molecule of polyvalent carboxylic acid are bonded to one molecule of glycerin is particularly preferable.

Although it does not specifically limit as said polyvalent carboxylic acid used for the monoglyceride of the said polyvalent carboxylic acid, For example, a succinic acid, a citric acid, tartaric acid, diacetyl tartaric acid, malic acid, and adipic acid are preferable.
The fatty acid used in the monoglyceride of the polyvalent carboxylic acid is not limited, but is preferably a saturated or unsaturated fatty acid having 8 to 22 carbon atoms, specifically, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid. Examples include acid, stearic acid, behenic acid, oleic acid and the like.

The carboxyl group-containing organic acid monoglyceride that can be used in the present invention is generally an anhydride of a polyvalent organic acid according to the method described in JP-A-4-218597, JP-A-3823524, etc. And fatty acid monoglyceride.
The reaction is usually carried out under solvent-free conditions. For example, in the reaction of succinic anhydride and a fatty acid monoglyceride having 18 carbon atoms, the reaction is completed in about 90 minutes even at a temperature of about 120 ° C. The organic acid monoglyceride thus obtained is usually a mixture containing an organic acid, unreacted monoglyceride, diglyceride, and other oligomers. In the present invention, such a mixture may be used as it is.
When it is desired to increase the purity of the carboxyl group-containing organic acid monoglyceride, the carboxyl group-containing organic acid monoglyceride in the mixture as described above may be purified by distillation or the like. Commercially available as distilled monoglyceride can be used. Examples of commercially available products of the carboxyl group-containing organic acid monoglyceride include Poem K-37V (glycerine citrate oleate), Kao Step SS (glycerin stearic acid / palmitic acid succinate), and the like.

The addition amount of the organic acid represented by the general formula (6) contained in the film of the present invention is a ratio of 0.1% by mass to 20% by mass with respect to the cyclic olefin-based resin, and 0.5% by mass. % To 10% by weight is particularly preferable, 0.6% to 5% by weight is more preferable, and 1.5% to 5% by weight is more particularly preferable.
If the addition amount is 0.1% or more, the polarizer durability improving effect and the peelability improving effect are sufficient. An addition amount of 20% by mass or less is preferable because the organic acid hardly bleeds out at a high temperature and high humidity, and the orthogonal transmittance of the polarizing plate hardly increases.
The molecular weight of the organic acid represented by the general formula (6) is preferably 200 to 1,000.

《Light stabilizer》
Light stabilizers include hindered amine light stabilizer (HALS) compounds, which are known compounds, such as columns 5-11 of US Pat. No. 4,619,956 and US Pat. , 839,405, as described in columns 3 to 5, including 2,2,6,6-tetraalkylpiperidine compounds, or acid addition salts thereof or complexes of them with metal compounds It is. Such a compound includes a compound represented by the following general formula (7).

In the general formula (7), R ¹ and R ² are H or a substituent. Specific examples of hindered amine light stabilizer compounds include 4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-allyl-4-hydroxy-2,2,6,6-tetramethylpiperidine, 1-benzyl. -4-hydroxy-2,2,6,6-tetramethylpiperidine, 1- (4-tert-butyl-2-butenyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine, 4-stearoyl Oxy-2,2,6,6-tetramethylpiperidine, 1-ethyl-4-salicyloyloxy-2,2,6,6-tetramethylpiperidine, 4-methacryloyloxy-1,2,2,6 6-pentamethylpiperidine, 1,2,2,6,6-pentamethylpiperidin-4-yl-β (3,5-di-t-butyl-4-hydroxyphenyl) -propionate, -Benzyl-2,2,6,6-tetramethyl-4-piperidinyl maleate, (di-2,2,6,6-tetramethylpiperidin-4-yl) -adipate, (di- 2,2,6,6-tetramethylpiperidin-4-yl) -sebacate, (di-1,2,3,6-tetramethyl-2,6-diethyl-piperidin-4-yl) -sebacate, (di -1-allyl-2,2,6,6-tetramethyl-piperidin-4-yl) -phthalate, 1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl-acetate, trimellitic acid- Tri- (2,2,6,6-tetramethylpiperidin-4-yl) ester, 1-acryloyl-4-benzyloxy-2,2,6,6-tetramethylpiperidine, dibutyl-malonic acid-di -(1,2,2,6,6-pentamethyl-piperidin-4-yl) -ester, dibenzyl-malonic acid-di- (1,2,3,6-tetramethyl-2,6-diethyl-piperidine- 4-yl) -ester, dimethyl-bis- (2,2,6,6-tetramethylpiperidine-4-oxy) -silane, tris- (1-propyl-2,2,6,6-tetramethylpiperidine- 4-yl) -phosphite, tris- (1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) -phosphate, N, N′-bis- (2,2,6,6- Tetramethylpiperidin-4-yl) -hexamethylene-1,6-diamine, N, N'-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -hexamethylene-1,6- Diacetamide, 1-acetyl -4- (N-cyclohexylacetamide) -2,2,6,6-tetramethyl-piperidine, 4-benzylamino-2,2,6,6-tetramethylpiperidine, N, N'-bis- (2, 2,6,6-tetramethylpiperidin-4-yl) -N, N'-dibutyl-adipamide, N, N'-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -N , N'-dicyclohexyl- (2-hydroxypropylene), N, N'-bis- (2,2,6,6-tetramethylpiperidin-4-yl) -p-xylylene-diamine, 4- (bis-2 -Hydroxyethyl) -amino-1,2,2,6,6-pentamethylpiperidine, 4-methacrylamide-1,2,2,6,6-pentamethylpiperidine, α-cyano-β-methyl-β- [N- (2,2 6,6-tetramethyl-piperidin-4-yl)] - amino - acrylic acid methyl ester. Examples of preferred hindered amine light stabilizers include the following HALS-1 and HALS-2. In the following, n represents the number of repeating units.

<Acid scavenger>
The acid scavenger preferably comprises an epoxy compound as an acid scavenger described in US Pat. No. 4,137,201. Epoxy compounds as such acid scavengers are known in the art and are derived by condensation of various polyglycol diglycidyl ethers, particularly about 8 to 40 moles of ethylene oxide per mole of polyglycol. Glycol, diglycidyl ether of glycerol, etc., metal epoxy compounds (such as those conventionally used in and with vinyl chloride polymer compositions), epoxidized ether condensation products, diphenols of bisphenol A Glycidyl ether (i.e., 4,4'-dihydroxydiphenyldimethylmethane), epoxidized unsaturated fatty acid ester (especially an ester of an alkyl of about 4 to 2 carbon atoms of a fatty acid of 2 to 22 carbon atoms (e.g. butyl Epoxy stearate) , And various epoxidized long chain fatty acid triglycerides and the like (e.g., epoxidized vegetable oils and other unsaturated natural oils, which are represented and exemplified by compositions such as epoxidized soybean oil, these are sometimes epoxidized natural glycerides or These are referred to as unsaturated fatty acids and these fatty acids generally contain 12 to 22 carbon atoms)). Particularly preferred are commercially available epoxy group-containing epoxide resin compounds EPON 815c and other epoxidized ether oligomer condensation products represented by the following general formula (8).

  In the general formula (8), n is 0-12. Further possible acid scavengers that can be used include those described in paragraphs 87 to 105 of JP-A-5-194788.

"Antioxidant"
In the present invention, in order to improve the thermal decomposability and thermal colorability during molding, it is preferable that the resin mixture such as a cyclic olefin resin contains an antioxidant. In the present invention, a preferred antioxidant is a phosphorus-based or phenol-based antioxidant, and preferably contains at least one phosphorus-based antioxidant (phosphorus-based deterioration inhibitor). In particular, it is more preferable to combine a phosphorus-based and phenolic antioxidant at the same time.

[Film Production Method]
<Step of forming a cyclic olefin-based resin into a film>
In the production method of the present invention, a solution casting film forming method or a melt film forming method may be used in the step of forming the cyclic olefin-based resin into a film.

(Solution casting method)
(Manufacture of dope)
In the production method of the present invention, each component that is preferably contained in the dope will be described.

  In the dope used in the present invention, the amount of the cyclic olefin-based resin is preferably adjusted so as to be contained in an amount of 10 to 40% by mass in the obtained dope. The amount of the cyclic olefin resin is more preferably 10 to 30% by mass.

  As the solvent used in the dope in the production method of the present invention, a known solvent can be adopted as long as it is a solvent used for solution casting. From the viewpoint of further reducing haze, the number of carbon atoms is 3 to 12. It is preferable to include a solvent selected from ethers of the above, ketones having 3 to 12 carbon atoms, esters having 3 to 12 carbon atoms, and halogenated hydrocarbons having 1 to 6 carbon atoms. The ether, ketone and ester may have a cyclic structure. A compound having two or more functional groups of ether, ketone and ester (that is, —O—, —CO— and —COO—) can also be used as a solvent. The solvent may have another functional group such as an alcoholic hydroxyl group. In the case of a solvent having two or more types of functional groups, the number of carbon atoms may be within the specified range of the compound having any functional group.

Examples of the ether having 3 to 12 carbon atoms include diisopropyl ether, dimethoxymethane, dimethoxyethane, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, anisole and phenetole.
Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclohexanone and methylcyclohexanone.
Examples of the esters having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate and pentyl acetate.
Examples of the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol and 2-butoxyethanol.
The number of carbon atoms of the halogenated hydrocarbon is preferably 1 or 2, and most preferably 1. The halogen of the halogenated hydrocarbon is preferably chlorine. The proportion of halogen atoms substituted by halogen in the halogenated hydrocarbon is preferably 25 to 75 mol%, more preferably 30 to 70 mol%, and more preferably 35 to 65 mol%. More preferably, it is most preferable that it is 40-60 mol%. Examples of halogenated hydrocarbons include dichloromethane, chloroform, methyl chloride, carbon tetrachloride, trichloroacetic acid, methyl bromide, methyl uride, tri (tetra) chloroethylene, and the like, and preferably contains at least dichloromethane.

In the present invention, the poor solvent is preferably contained in a proportion of 3 to 30% by mass, more preferably 5 to 20% by mass. By including a poor solvent within the above range, compatibility with cellulose acylate is improved, and haze tends to be further reduced, which is preferable.
Furthermore, it is preferable that the boiling point of a poor solvent is 120 degrees C or less, and it is more preferable that it is 40-100 degreeC. By setting the boiling point to 120 ° C. or less, the drying rate of the solvent can be further increased, which is preferable. Examples of such a poor solvent include methanol, ethanol, propanol, butanol and water, and methanol is more preferable.

  The dope can be prepared by a general method. A general method means processing at a temperature of 0 ° C. or higher (ordinary temperature or high temperature). The solution can be prepared by using a dope preparation method and apparatus in a normal solvent cast method. The dope can be prepared by stirring cellulose acylate and a solvent at room temperature (0 to 40 ° C.). The high concentration solution may be stirred under pressure and heating conditions. Specifically, the cyclic olefin-based resin and the solvent are put in a pressure vessel, sealed, and stirred while being heated to a temperature equal to or higher than the boiling point of the solvent at normal temperature and in a range where the solvent does not boil. The heating temperature is usually 40 ° C or higher, preferably 60 to 200 ° C, more preferably 80 to 110 ° C.

Each component may be roughly mixed in advance and then placed in a container (tank or the like). Moreover, you may put into a container sequentially. The container needs to be configured so that it can be stirred. The container can be pressurized by injecting an inert gas such as nitrogen gas. Moreover, you may utilize the raise of the vapor pressure of the solvent by heating. Or after sealing a container, you may add each component under pressure.
When heating, it is preferable to heat from the outside of the container. For example, a jacket type heating device can be used. The entire container can also be heated by providing a plate heater outside the container and piping to circulate the liquid.
It is preferable to provide a stirring blade inside the container and stir using this. The stirring blade preferably has a length that reaches the vicinity of the wall of the container. A scraping blade is preferably provided at the end of the stirring blade in order to renew the liquid film on the vessel wall.
Instruments such as a pressure gauge and a thermometer may be installed in the container. Each component is dissolved in a solvent in a container. The prepared dope is taken out of the container after cooling, or taken out and then cooled using a heat exchanger or the like.

  The dope can also be prepared by a cooling dissolution method.

(Film forming process)
In this invention, it is preferable to manufacture a cyclic olefin resin film from the prepared dope by a solvent cast method.

  As the method and equipment for producing the film of the present invention, the same solution casting film forming method and solution casting film forming apparatus as those conventionally used for producing cellulose triacetate films are used. The dope (cyclic olefin resin solution) prepared from the dissolving machine (kettle) is temporarily stored in a storage kettle, and the foam contained in the dope is defoamed for final preparation. A pressure die that can adjust the slit shape of the die base and facilitates uniform film thickness is preferred. The pressure die includes a coat hanger die and a T die, and any of them is preferably used. The surface of the metal support is a mirror surface. In order to increase the film forming speed, two or more pressure dies may be provided on the metal support, and the dope amount may be divided and stacked. Or it is also preferable to obtain the film of a laminated structure by the co-casting method which casts several dope simultaneously.

  The dope is sent from the dope discharge port to the pressure die through a pressure metering gear pump capable of delivering a constant amount of liquid with high accuracy, for example, by the number of rotations, and the dope is run endlessly from the die (slit) of the pressure die. It is preferable to peel off the raw dry dope film (also referred to as web) from the metal support at a peeling point which is uniformly cast on the metal support and the metal support has made one round. Both ends of the obtained web are sandwiched between clips, transported with a tenter and dried, then transported with a roll group of a drying device, dried, and wound up to a predetermined length with a winder. The combination of the tenter and the roll group dryer varies depending on the purpose. In the solution casting film forming method used for the functional protective film for electronic displays, in addition to the solution casting film forming apparatus, surface processing on films such as an undercoat layer, an antistatic layer, an antihalation layer, a protective layer, etc. Therefore, a coating device is often added. Although each manufacturing process is described briefly below, it is not limited to these.

The prepared dope is preferably cast on an endless metal support, for example, a metal drum or a metal support (band or belt), and the solvent is evaporated to form a film. The dope before casting is preferably adjusted in concentration so that the amount of cellulose is 10 to 35% by mass. The surface of the drum or band is preferably finished in a mirror state. For casting and drying methods in the solvent casting method, U.S. Pat. No. 736892, JP-B Nos. 45-4554, 49-5614, JP-A-60-176834, No. 60-203430, and No. 62-1115035.
Further, JP 2000-301555, JP 2000-301558, JP 7-032391, JP 3-193316, JP 5-086212, JP 62-037113, JP 2-276607. The cellulose acylate film-forming techniques described in JP-A-55-014201, JP-A-2-111511, and JP-A-2-208650 can be applied in the present invention.

  The dope is preferably cast on a drum or band having a surface temperature of 30 ° C. or lower, and particularly preferably at a metal support temperature of −50 to 20 ° C. In the production method of the present invention, it is preferable to blow dry air from both the back surface and the front surface of the metal support on the dope cast on the metal support. After casting, it is preferable to dry it by applying air for 2 seconds or more. The obtained film can be peeled off from the drum or band, and further dried by high-temperature air whose temperature is successively changed from 100 ° C. to 160 ° C. to evaporate the residual solvent. The above method is described in Japanese Patent Publication No. 5-17844. According to this method, it is possible to shorten the time from casting to stripping. In order to carry out this method, it is necessary for the dope to gel at the surface temperature of the drum or band during casting.

In the production method of the present invention, it is preferable to use two or more types of dopes having different types and concentrations of the cyclic olefin resin as the dope and to co-cast each dope on the support.
In the formation of the film of the present invention, it is preferable to use a lamination casting method such as a co-casting method, a sequential casting method, and a coating method. Particularly preferable from the viewpoint.
When manufacturing by the co-casting method and the sequential casting method, first, the cyclic olefin resin solution (dope) for each layer is prepared. In the co-casting method (multi-layer simultaneous casting), a casting dope for each layer (which may be three layers or more) is simultaneously pressed from another slit or the like on a casting support (band or drum). This is a casting method in which the dope is extruded from the casting gies to be cast, and each layer is cast at the same time.

  In the sequential casting method, the casting dope for the first layer is first extruded from the casting giusa on the casting support, cast, and dried on the second layer without drying or drying. Extrude the casting dope for casting from the casting gieser, cast the dope sequentially to the third layer or more, if necessary, peel it off from the support at an appropriate time, and dry it. This is a casting method for forming a film. In general, the core layer film is formed into a film by a solution casting method to prepare a coating solution to be applied to the surface layer, and then applied to the film one side at a time or both sides simultaneously using an appropriate applicator. This is a method of forming a film having a laminated structure by applying and drying a liquid.

(Stripping)
In this step, the web in which the solvent is evaporated on the metal support is peeled off at the peeling position. The peeled web is sent to the next process. In addition, if the residual volatile content (the following formula) of the web at the time of peeling is too large, it is difficult to peel off, or conversely, if it is peeled off after being sufficiently dried on the metal support, a part of the web is partially It may come off.

The production method of the present invention preferably includes a step of stripping the film from the metal support with a residual volatile content H1 satisfying the following formula (i) regardless of the type of the cyclic olefin resin.
Formula (i) 20% ≦ H1 ≦ 60%
The H1 is preferably 22 to 55%, particularly preferably 25 to 45%.
The amount of residual solvent can be represented by the following formula.
Residual solvent amount (% by mass) = {(MN) / N} × 100
Here, M is the mass of the web at an arbitrary point in time, and N is the mass when the mass M is dried at 110 ° C. for 3 hours.

  A method for drying a web that has been dried on a drum or belt and peeled off will be described. The web peeled at the peeling position immediately before the drum or belt makes one round is conveyed by alternately passing through a group of rolls arranged in a staggered manner, or both ends of the peeled web are gripped by clips or the like. It is preferably conveyed by a non-contact conveyance method or the like.

  In the production method of the present invention, it is preferable that the film passes at least 3 pass rolls having a wrap angle of 60 ° or more, and passes 5 or more pass rolls in the transitional part from the stripping step to the stretching step. It is more preferable to pass through 7 to 51 pass rolls. In addition, as described above, the production method of the present invention preferably includes at least one dancer as the pass roll having a wrap angle of 60 ° or more, and preferably has one dancer. In addition, the wrap angle in this specification means the size of the center angle connecting the arc region where the film is wrapping the roll and the roll center, for example, the film passes through rolls arranged in a complete staggered pattern. In this case, the wrap angle is 180 degrees.

  Drying is performed by a method of applying wind at a predetermined temperature to both sides of the web (film) being conveyed or a method using a heating means such as a microwave. Since rapid drying may impair the flatness of the film to be formed, it is preferable to dry at a temperature at which the solvent does not foam in the initial stage of drying, and to dry at a high temperature after the drying proceeds. In the drying process after peeling from the support, the film tends to shrink in the longitudinal direction or the width direction by evaporation of the solvent. Shrinkage increases with drying at higher temperatures. Drying while suppressing this shrinkage as much as possible is preferable for improving the flatness of the finished film. From this point, for example, as shown in Japanese Patent Laid-Open No. 62-46625, a method in which all or part of the drying process is performed while holding the width at both ends of the web with clips or pins in the width direction. (Tenter method) is preferable. It is preferable that the drying temperature in the said drying process is 100-145 degreeC. The drying temperature, the amount of drying air, and the drying time vary depending on the solvent to be used.

(Stretching process)
The production of the film of the present invention may include a step of stretching the web (film) peeled from the support.

  The production method of the present invention includes a step of stretching the peeled film in the film transport direction by 2 to 100% in the state of residual volatile matter H2 satisfying the following formula (ii), and the peeled film: It includes a step of stretching 2 to 150% in a direction orthogonal to the film conveyance direction in a state of residual volatile content H3 satisfying the formula (i), and the stretching step preferably satisfies the following formula (iv). Formula (ii) 10% ≦ H2 ≦ 60% Formula (iii) 5% ≦ H3 ≦ 45% Formula (iv) TD stretch ratio ≧ 2% (In the formula, TD stretch ratio is stretched in a direction perpendicular to the film transport direction) (Represents magnification (unit:%))

The draw ratio in stretching in the film transport direction is preferably 1 to 25%, and more preferably 1 to 10%.
Here, the “stretch ratio (%)” means that obtained by the following formula.
Stretch ratio (%) = 100 × {(Length after stretching) − (Length before stretching)} / Length before stretching

  There is no limitation in particular in the method of extending | stretching a web to a film conveyance direction. For example, a method in which a difference in peripheral speed is applied to a plurality of rolls, and the roll peripheral speed difference is used to stretch in the longitudinal direction, the both ends of the web are fixed with clips and pins, and the interval between the clips and pins is increased in the traveling direction. And a method of stretching in the vertical direction, or a method of stretching in the vertical and horizontal directions by extending the length and width simultaneously. Of course, these methods may be used in combination. In the case of the so-called tenter method, driving the clip portion by a linear drive method is preferable because smooth stretching can be performed and the risk of breakage and the like can be reduced. For the stretching in the longitudinal direction, an apparatus having two nip rolls is used, and the rotational speed of the nip roll on the outlet side is made faster than the rotational speed of the nip roll on the inlet side. The resin film is preferably stretched preferably. By performing such stretching, the expression of retardation can be adjusted.

At this time, the H2 is preferably 20 to 55%, and more preferably 25 to 50%.
If the residual volatile content in the web is too large, the effect of stretching cannot be obtained, and if it is too small, stretching becomes extremely difficult and the web may break.

In the production method of the present invention, the stretching in the film transport direction is preferably performed while controlling the tension fluctuation value to be less than 10 N / m, more preferably less than 8 N / m, and more preferably 0 N / m. It is particularly preferable to control to m to 6 N / m.
The stretching ratio in stretching in the direction orthogonal to the film conveying direction is preferably 1 to 60%, and more preferably 1 to 10%.

  There is no limitation in particular in the method of extending | stretching a web in the direction orthogonal to a film conveyance direction. For example, a method in which both ends of the web are fixed with clips or pins and the interval between the clips or pins is expanded in the horizontal direction and stretched in the horizontal direction, or a method in which the webs are expanded in the vertical and horizontal directions and stretched in both the vertical and horizontal directions. Of course, these methods may be used in combination. In the case of the so-called tenter method, driving the clip portion by a linear drive method is preferable because smooth stretching can be performed and the risk of breakage and the like can be reduced. In this invention, it is preferable to extend | stretch using a tenter apparatus as a method of extending | stretching in the direction orthogonal to a film conveyance direction.

At this time, the H3 is preferably 8 to 40%, and more preferably 10 to 35%.
If the residual volatile content in the web is too large, the effect of stretching cannot be obtained, and if it is too small, stretching becomes extremely difficult and the web may break.

  Moreover, when extending | stretching in a film width direction, distribution may arise in a refractive index by width. This is sometimes seen when using, for example, the tenter method, but it is a phenomenon that occurs when the film is stretched in the width direction and contraction force is generated at the center of the film and the end is fixed. It is thought to be called the bowing phenomenon. Even in this case, by stretching in the casting direction, it is possible to suppress the bowing phenomenon and to improve the distribution of the width retardation. Furthermore, the film thickness fluctuation | variation of the film obtained by extending | stretching in the biaxial direction orthogonal to each other can be reduced. When the film thickness fluctuation | variation of a cyclic olefin resin film is too large, it will become the nonuniformity of phase difference. The thickness variation of the cyclic olefin-based resin film is preferably in the range of ± 3%, and more preferably ± 1%. Also for the above purpose, the method of stretching in the biaxial directions perpendicular to each other so as to satisfy the formula (iv) is effective.

In the production method of the present invention, the stretching temperature is Te + 30 ° C. or lower, provided that the stretching temperature ≦ Te + 30 ° C. (Ib)
Te = T [tan δ] −ΔTm (IIb)
ΔTm = Tm (0) −Tm (x) (IIIb)
(In the formula (IIb), T [tan δ] represents the temperature at which tan δ shows a peak when the dynamic viscoelasticity tan δ of the cyclic olefin resin when the residual solvent amount is 0% is measured, and Tm (0) is The crystal melting temperature of the cyclic olefin resin when the residual solvent amount is 0% is represented, and Tm (x) represents the crystal melting temperature of the cyclic olefin resin when the residual solvent amount relative to the cyclic olefin resin is x%. )).

  Hereinafter, stretching in such a temperature range is also referred to as low temperature stretching. By low-temperature stretching the film formed in a film shape, it is possible to increase Rth expression without increasing the film thickness of the film of the present invention, that is, Rth (550) / d can be further increased, which is preferable. . Although not bound by any theory, Re can be expressed without lowering Rth because the orientation of the polymer or additive during stretching is less likely to occur in the low-temperature stretching than in high-temperature stretching. The stretching temperature is more preferably Te-30 to Te ° C. The preferred range is the same when stretching in the film transport direction and when stretching in the film width direction.

(Heat treatment process)
The film production method of the present invention may be provided with a heat treatment step as described above after the drying step. The heat treatment in the heat treatment step may be performed after completion of the drying step, and may be performed immediately after the stretching / drying step, or may be separately provided only after the winding by a method described later after the completion of the drying step. .

The heat treatment is performed by a method of applying a wind at a predetermined temperature to the film being conveyed or a method using a heating means such as a microwave.
The heat treatment is preferably performed at a temperature of 150 to 200 ° C., more preferably 160 to 180 ° C. The heat treatment is preferably performed for 1 to 20 minutes, more preferably 5 to 10 minutes.

(Take-up)
As a winder for winding the obtained film, a commonly used winder can be used, such as a constant tension method, a constant torque method, a taper tension method, a program tension control method with a constant internal stress, etc. It can be wound up by the winding method. In the cyclic olefin-based resin film roll obtained as described above, the slow axis direction of the film is preferably ± 2 degrees with respect to the winding direction (longitudinal direction of the film), and more preferably ± 1 degree. It is preferable that it is the range of these. Alternatively, it is preferably ± 2 ° with respect to the direction perpendicular to the winding direction (film width direction), and more preferably within ± 1 °. In particular, the slow axis direction of the film is preferably within ± 0.1 degrees with respect to the winding direction (longitudinal direction of the film). Alternatively, it is preferably within ± 0.1 degrees with respect to the width direction of the film.

(Residual volatiles)
The cyclic olefin-based resin film obtained by the above-described method for producing a film of the present invention has a dimensional stability of 1% by mass or less, and further 0.2% by mass or less in terms of residual volatile content of the final finished film. It is preferable for obtaining a good film.

  In addition, in the manufacturing method of this invention, the process of manufacturing a film may be included, detecting the slow axis direction of the film longitudinal method in-line. A preferred embodiment in that case is the same as the embodiment described above as a method for obtaining in-line the standard deviation of the slow axis orientation of the film longitudinal method of the film of the present invention.

(Melting method)
Next, a melt film forming method will be described as a film manufacturing method.
The melt film forming method is a method of forming a film by melting the composition containing the cyclic olefin-based resin of the present invention with heat using an extruder or the like and extruding it from a die. In more detail, the following method can be mentioned, for example.

A preferable production method of the film of the present invention by a melt film-forming method includes a step of melt-extruding a composition containing the cyclic olefin-based resin of the present invention, which is a thermoplastic resin, from a die, and a melt-extruded melt (hereinafter, A step of forming a film by continuously pressing between a first clamping surface and a second clamping surface constituting a clamping device.
The melt is extruded so that the temperature difference between the temperature of the melt coming out from the center part of the die and the temperature of the melt coming out from the end of the die is within 10 ° C., and 20 to 500 MPa is applied to the melt by the holding device. And a shear stress of 3000 to 30000 N per 1 m width of the melt is applied by the clamping device, and the moving speed of the first clamping surface is made faster than the moving speed of the second clamping surface. To do.

Examples of the clamping device having different speeds on the first clamping surface and the second clamping surface include, for example, a combination of two rolls having different peripheral speeds, and rolls having different speeds described in Japanese Patent Application Laid-Open No. 2000-219752. Examples include a combination of touch belts (single-sided belt method), a combination of belts and belts (double-sided belt method), and the like. Among these, from the viewpoint of being able to apply a high pressure of 20 to 500 MPa uniformly and from the standpoint of expression of the inclined structure, it is preferable that the two rolls have different peripheral speeds. The roll pressure can be measured by passing a pressure measurement film (such as a prescale for medium pressure by Fuji Film) through two rolls.
Hereinafter, the production method of the film of the present invention by the melt film-forming method (hereinafter also referred to as the production method of the present invention) will be described in detail.

(Melt extrusion)
In the production method of the present invention, first, a composition containing the thermoplastic resin (cyclic olefin resin) (sometimes referred to as “thermoplastic resin composition”) is melt-extruded. Prior to melt extrusion, the thermoplastic resin composition is preferably pelletized. The thermoplastic resin composition is dried, melted at 150 ° C. to 300 ° C. using a twin-screw kneading extruder, and then extruded into noodles, and solidified in air or water and cut. Further, after melting by an extruder, it can be pelletized by an underwater cutting method in which it is cut while being directly extruded from a die into water. Extruders used for pelletization include single screw extruders, non-meshing different direction rotating twin screw extruders, meshing different direction rotating twin screw extruders, and meshing same direction rotating twin screw extruders. Etc. can be used. The number of revolutions of the extruder is preferably 10 rpm to 1000 rpm, more preferably 20 rpm to 700 rpm. The extrusion residence time is 10 seconds to 10 minutes, more preferably 20 seconds to 5 minutes.
No particular limitation is imposed on the size of the pellets is generally about 10mm ³ ~1000mm ^3, more preferably about 30 mm ³ 500 mm ^3.

  It is preferred to reduce the moisture in the pellets prior to melt extrusion. A preferable drying temperature is 40 to 200 ° C, more preferably 60 to 150 ° C. Thereby, the moisture content is preferably 1.0% by mass or less, and more preferably 0.1% by mass or less. Drying may be performed in air, nitrogen, or vacuum.

  Next, the dried pellets are supplied into the cylinder through the supply port of the extruder, and are kneaded and melted. The inside of the cylinder is composed of, for example, a supply unit, a compression unit, and a measurement unit in order from the supply port side. The screw compression ratio of the extruder is preferably 1.5 to 4.5, the ratio of the cylinder length to the cylinder inner diameter (L / D) is preferably 20 to 70, and the cylinder inner diameter is preferably 30 mm to 150 mm. The extrusion temperature is determined according to the melting temperature of the thermoplastic resin, but generally about 190 to 300 ° C is preferable. Further, in order to prevent the molten resin from being oxidized by the residual oxygen, it is also preferable to carry out the inside of the extruder in an inert (nitrogen or the like) air flow or while evacuating it using a vented extruder.

  It is preferable to provide a filtration apparatus incorporating a breaker plate type filtration or a leaf type disk filter for filtering foreign matter in the thermoplastic resin composition. Filtration may be performed in one stage or may be performed in multistage filtration. The filtration accuracy is preferably 15 μm to 3 μm, more preferably 10 μm to 3 μm. It is desirable to use stainless steel as the filter medium. As the configuration of the filter medium, a knitted wire, a sintered metal fiber or metal powder (sintered filter medium) can be used, and among them, a sintered filter medium is preferable.

  In order to reduce the fluctuation of the discharge amount and improve the thickness accuracy, it is preferable to provide a gear pump between the extruder and the die. Thereby, the resin pressure fluctuation width in the die can be within ± 1%. In order to improve the quantitative supply performance by the gear pump, a method of controlling the pressure before the gear pump to be constant by changing the number of rotations of the screw can also be used.

  The molten resin is melted by the extruder configured as described above, and the molten resin is continuously fed to the die via a filter and a gear pump as necessary. The die may be any of a T die, a fish tail die, and a hanger coat die. It is also preferable to insert a static mixer immediately before the die to increase the uniformity of the resin temperature.

  In the manufacturing method of the present invention, the heat radiation amount of the die is controlled so that the temperature difference between the temperature of the melt exiting from the center portion of the die and the temperature of the melt exiting from the end of the die is within 10 ° C. That is, the die is not at a constant temperature across its width. Generally, both ends of the melt exiting from the die are likely to come into contact with the outside air, so the temperature is likely to decrease.

  In the production method of the present invention, the temperature difference is not particularly limited, but it is preferable to apply the temperature difference by combining any one or a plurality of the following methods.

(1) The method of providing the said temperature difference by making the heat dissipation of the center part of the said die higher than the heat dissipation of both ends of the die. Specifically, there is a method of adjusting the heat dissipation rate by attaching a fan or a fan to the center of the die and not attaching them to both ends.

(2) A method of imparting the temperature difference by continuously decreasing the heat radiation amount of the die from the center of the die to both ends of the die. Specifically, there is a method in which the entire die is covered with a uniform heat insulating material, and the heat insulating material is shaved so that the heat insulating material is gradually thinned from both ends to the central portion.

(3) The method of providing the said temperature difference by covering the both ends of the said die with a heat insulation member with a high heat insulation effect, and covering the center part of the said die with a heat insulation member with a low heat insulation effect. Specifically, there is a method in which the entire die is covered with a uniform heat insulating material and a fine hole is formed only in the central portion of the heat insulating material. Moreover, the method of installing the heat insulating material from which heat conductivity differs in the die center part and die | dye both ends, respectively is mentioned.

(4) The temperature difference is obtained by covering the die with a heat insulating member having the same composition, increasing the thickness of the heat insulating member at both ends of the die, and decreasing the thickness of the heat insulating member at the center of the die. How to grant. Specifically, there may be mentioned a method in which two types of heat insulating materials having the same thermal conductivity and different thicknesses are used and installed at the die center portion and the die end portions, respectively.

(5) The method of providing the said temperature difference by making the area of the heat insulation member which covers the outer surface of the both ends of the said die larger than the area of the heat insulation member which covers the outer surface of the center part of die | dye. Specifically, a method in which both ends of the die are completely covered with a heat insulating material, and only a part of the die central portion is covered with the same heat insulating material. In addition, a method in which both ends of the die are completely covered with a heat insulating material and a heat insulating material is not used in the central portion of the die is also exemplified.

(6) The method of giving the said temperature difference because the said die | dye is a shape where the outer surface area of the center part of die | dye is larger than the outer surface area of die both ends. Specifically, an aspect in which the degree of heat dissipation in the width direction of the die is different is exemplified. Examples of such a method include a method of processing the die itself such as digging a groove in the die so that the outer surface area of the central portion of the die is larger than the outer surface area of both ends of the die.

  In addition, as a method of controlling the heat conductivity of a heat insulating material, the method of using a heat insulating material of a different material and the method of using a heat insulating material with a different foaming rate are mentioned. Moreover, although there is no restriction | limiting in particular as said heat insulating material, a foaming polyimide, glass wool, etc. can be used.

  In the production method of the present invention, when the temperature difference is applied by the methods (1) to (6), the temperature of the melt is uniform by setting the die set temperature to the same temperature at the center and both ends. From the viewpoint of more accurately controlling the property.

  The clearance of the die exit portion is generally 1.0 to 30 times the film thickness, preferably 5.0 to 20 times. In the manufacturing method of the present invention, the radius of curvature of the tip of the die lip is not particularly limited, and a known die can be used.

  The die is preferably capable of adjusting the thickness of a film formed at intervals of 5 to 50 mm. An automatic thickness adjustment die that calculates downstream film thickness and thickness deviation and feeds back the results to the die thickness adjustment device is also effective. In addition to the single layer film forming apparatus, it is also possible to manufacture using a multilayer film forming apparatus. Thus, the residence time from when the resin enters the extruder through the supply port until it exits from the die is preferably 3 to 40 minutes, more preferably 4 to 30 minutes.

(cast)
Next, the melt of the thermoplastic resin is extruded from the die into a film, and the melt-extruded melt is continuously sandwiched between the first sandwiching surface and the second sandwiching surface constituting the sandwiching device, and then cooled and solidified. To obtain a film. At this time, either one of the first clamping surface and the second clamping surface is peeled off first from the melt, and then the other surface is peeled off from the melt, thereby stabilizing productivity and peeling failure. It is preferable from the viewpoint of suppressing the surface defect caused by. In the manufacturing method of the present invention, the moving speed of the first pressing surface is faster than the moving speed of the second pressing surface, but the surface to be peeled first is the second pressing surface even if it is the first pressing surface. However, from the viewpoint of suppressing the peeling dan, it is preferable that the first surface to be peeled first is the first pinching surface (pressing surface having a high moving speed).

In the production method of the present invention, when the melt-extruded melt is continuously sandwiched between the first sandwiching surface and the second sandwiching surface constituting the sandwiching device, the pressure between the sandwiching devices is 20 to 500 MPa. It is preferable to apply. By setting the pressure between the clamping devices within this range, even if temperature unevenness (viscosity unevenness) exists in the melt, it is difficult for slip to occur, and scratches are hardly generated. If it is 20 MPa or more, the clamping device is unlikely to slip, and scratches due to this are unlikely to occur. If it is 500 MPa or less, it is possible to prevent scratching with a slight slip, which is preferable. A more preferable pressure is 25 to 400 MPa, and further preferably 30 to 250 MPa.
Further, the γ can be achieved by setting the pressure between the clamping devices. That is, if it is 20 MPa or more, the effect of the speed difference can be sufficiently exhibited (the effect of shear can be sufficiently transmitted to the film), and the above γ can be exhibited. On the other hand, if it is 500 MPa or less, the shearing force does not propagate to the melt and γ does not become too large. In either case, the viewing angle when incorporated in a liquid crystal display panel is improved, and when the viewing angle is improved in this way, the image becomes easier to see when assembled on the liquid crystal display board, and as a result, interference unevenness becomes less visible. preferable.

In the manufacturing method of the present invention, the moving speed ratio between the first clamping surface and the second clamping surface of the clamping device defined by the following formula (I) is adjusted to 0.60 to 0.99, and the molten resin is sandwiched. It is preferable to apply a shear stress when passing through the pressure device to produce the film of the present invention. The moving speed ratio of the clamping device is preferably 0.60 to 0.99, and more preferably 0.75 to 0.98.
Movement speed ratio = speed of the second clamping surface / speed of the first clamping surface (I)

  The range of the viscosity of the melt in the production method of the present invention is preferably 300 to 8000 Pa · s, more preferably 500 to 6000 Pa · s, and particularly preferably 700 to 4000 Pa · s. The viscosity of the melt referred to here refers to the viscosity at the temperature at the moment when the melt is extruded from the die.

(Discharge temperature)
In the production method of the present invention, the discharge temperature (resin temperature at the die outlet) is such that the temperature difference between the temperature of the melt exiting from the center portion of the die and the temperature of the melt exiting from the die end is within 10 ° C. It is characterized by. By thus controlling the temperature of the melt discharged from the die uniformly in the width direction, the unevenness in the MD direction of Re [0 °] and the unevenness in the MD direction of γ are controlled within the scope of the present invention. be able to. In addition, it is possible to remarkably reduce an end portion in which the unevenness in the MD direction of Re [0 °] and the unevenness in the MD direction of γ, which are simultaneously cut as film ears, are poor.
The discharge temperature is preferably Tg + 50 to Tg + 200 ° C., more preferably Tg + 70 to Tg + 180 ° C., and particularly preferably Tg + 90 to Tg + 150 ° C. from the viewpoint of improving the moldability of the resin and suppressing deterioration. preferable. That is, if Tg + 50 ° C. or higher, the viscosity of the resin becomes sufficiently low and the moldability becomes good, and if Tg + 200 ° C. or lower, the resin hardly deteriorates.

(Discharge rate)
In the production method of the present invention, the flow rate of the melt extruded from the die is 2.5 to 30 Kg / cm ² per die discharge port area, and unevenness in the MD direction of Re [0 °] and MD direction of γ This is preferable from the viewpoint of reducing the unevenness. More preferably the flow rate of the melt to be extruded from the die is 3~25Kg / cm ^2, and particularly preferably 4~20Kg / cm ^2.

(Air gap)
In the production method of the present invention, the air gap (distance from the die outlet to the melt landing point of the pinching device) is preferably as close as possible from the viewpoint of heat retention of the melt between the die and the pinching device, Specifically, the thickness is preferably 10 to 300 mm, more preferably 20 to 250 mm, and particularly preferably 30 to 200 mm.

(Shear stress)
In the production method of the present invention, a shear stress of 3000 to 30000 N per 1 m width of the melt is applied by the pinching device. The shear stress is preferably 5000 to 28000N, and more preferably 8000 to 25000N.

(Cast using two rolls)
Among the methods of continuously passing between the clamping devices, it is preferable to pass between two rolls (for example, a touch roll (first roll) and a chill roll (second roll)). In addition, in this specification, when it has multiple casting rolls which convey the said melt, the casting roll nearest to the most upstream die | dye is also called a chill roll. Hereinafter, the preferable aspect of the manufacturing method of this invention using two rolls is demonstrated.

In the method for producing a film of the present invention, there is no particular limitation on the landing point of the melt extruded from the die, and the landing point of the melt extruded from the die is closest to the touch roll and the cast roll. The distance from the vertical line passing through the midpoint of the gap in the portion may be zero or may be shifted.
The landing point of the melt refers to a point where the melt extruded from the die comes into contact (landing) with the touch roll or chill roll for the first time. The midpoint of the gap between the touch roll and the cast roll refers to the midpoint of the touch roll surface and the cast roll surface where the gap between the touch roll and the cast roll is the narrowest.

  In the method for producing a film of the present invention, from the viewpoint of reducing unevenness in the MD direction of Re [0 °] and unevenness in the MD direction of γ, the length (nip width) of the melt sandwiched between the two rolls is It is preferably greater than 0 mm and 2 mm or less, more preferably 0.3 to 1.8 mm, and particularly preferably 0.5 to 1.5 mm.

  The surfaces of the two rolls (for example, a touch roll and a casting roll) preferably have an arithmetic average height Ra of 100 nm or less, more preferably 50 nm or less, and still more preferably 25 nm or less.

  In the manufacturing method of the present invention, the touch pressure between the two rolls is 20 to 500 MPa. A more preferable touch pressure is the same as the effect of the pressure between the clamping devices.

  In the manufacturing method of the present invention, in order to pressurize the roll pressure in the above range, the cylinder set value is appropriately changed. The cylinder set value varies depending on the resin material used and the material of the two rolls. For example, when the effective width of the film-like melt is 2000 mm, it is preferably 30 to 1000 KN, and preferably 40 to 800 KN. Is more preferable, and 50 to 500 KN is particularly preferable.

  In the production method of the present invention, in order to pressurize the roll pressure in the above range, it is preferable to use a roll having a roll hardness of 45 HS or more. The Shore hardness of the two preferable rolls is preferably 50 HS or more, and more preferably 60 to 90 HS. The Shore hardness can be determined from the average value of values measured at 5 points in the roll width direction and 5 points in the circumferential direction using the method of JIS Z 2246.

  The material of the two rolls is preferably a metal from the viewpoint of achieving wide film formation with a film formation width of 1 m or more and high-speed film formation with a film formation speed of 10 m / min or more. That is, when wide film formation or high-speed film formation is performed, the stress applied to the touch roll increases, and roll deformation increases. By using a metal roll, the rigidity is strong, and even when stress increases as the width is increased, it is difficult to be deformed, and a touch failure associated therewith is less likely to occur. From the viewpoint of achieving the Shore hardness, the material of the two rolls is preferably a metal, more preferably stainless steel, and a roll whose surface is plated is also preferred. Moreover, if the material of two rolls is a metal, since the surface unevenness | corrugation is small and the surface of a film is hard to be damaged, it is preferable. On the other hand, a rubber roll or a metal roll lined with rubber can be used without particular limitation as long as the roll pressure can be achieved.

  In the production method of the present invention, the thickness of the touch roll is preferably 6 mm to 45 mm from the viewpoint of achieving wide film formation with a film formation width of 1 m or more and high-speed film formation with a film formation speed of 10 m / min or more. More preferably, it is 10 mm-40 mm, More preferably, it is 15 mm-35 mm. If the thickness of the touch roll is 6 mm or more, it is difficult to cause bending even when forming a wide film or a high-speed film, and this is preferable because it can suppress scratches. If the thickness of the touch roll is 45 mm or less, the heat exchange with the medium circulated inside the roll can be prevented from being deteriorated, and not only the optical unevenness is hardly generated, but also the roll is not too rigid, depending on the melt thickness unevenness, etc. Can be subtly deformed as appropriate. Thus, it is preferable to use a roll that can be deformed delicately because slip generation can be suppressed and generation of scratches can be suppressed. In the present invention, by using a roll having such a thickness, the generation of scratches can be further suppressed and interference unevenness can be suppressed. Conventional touch rolls made of metal are as thin as 2 to 5 mm as disclosed in JP-A-11-235747, or 50 mm or more like a calendar roll, and a roll with a thickness of 6 mm to 45 mm can be used. The effect at the time of adopting the roll having such a thickness has not been known.

  As for the touch roll, for example, JP-A-11-314263, JP-A-2002-36332, JP-A-11-235747, WO97 / 28950, JP-A-2004-216717, JP The thing of 2003-145609 gazette can be utilized.

<Extension process>
In the present invention, the film obtained by the melt film-forming method is particularly preferably biaxially stretched, in both the longitudinal direction (also referred to as the film conveying direction and MD direction) and the lateral direction (also referred to as the width direction and TD direction). Each is preferably stretched. Since the film obtained by the melt film-forming method does not easily develop the retardation (Rth) in the thickness direction, the orientation in the thickness direction can be improved by stretching and the desired Rth can be obtained.
The relaxation treatment may be performed in combination with transverse stretching and / or longitudinal stretching. These can be implemented by, for example, the following combinations.
(1) transverse stretching (2) transverse stretching → relaxation treatment (3) longitudinal stretching → lateral stretching (4) longitudinal stretching → lateral stretching → relaxation treatment (5) longitudinal stretching → relaxation treatment → lateral stretching → relaxation treatment (6) transverse Stretching → Longitudinal stretching → Relaxation treatment (7) Transverse stretching → Relaxation treatment → Longitudinal stretching → Relaxation treatment (8) Longitudinal stretching → Transverse stretching → Longitudinal stretching (9) Longitudinal stretching → Transverse stretching → Longitudinal stretching → Relaxation treatment (10) Longitudinal Stretching (11) Longitudinal stretching → relaxation treatment Among these, (3) to (9) are more preferable, and (3) to (7) are more preferable. Among these, (3) and (6) are more preferable. Furthermore, by such uniform stretching, the molecules that have been rounded in the film can be efficiently stretched. As a result, entanglement can be formed between the molecules, and the breaking strength can be improved.
Further, since the in-plane retardation may be increased depending on the stretching direction, it is preferable to cancel the in-plane direction retardation by adjusting the stretching ratio in the MD direction and the stretching ratio in the TD direction. Therefore, the ratio of the draw ratio in the MD direction / the draw ratio in the TD direction is preferably 0.8 to 1.2, and more preferably 0.9 to 1.1.

(Longitudinal stretching)
Longitudinal stretching can be achieved by installing two pairs of nip rolls and heating the gap between them so that the peripheral speed of the nip roll on the outlet side is higher than the peripheral speed of the nip roll on the inlet side. Under the present circumstances, the expression of the retardation of the thickness direction can be changed by changing the space | interval (L) between nip rolls, and the film width (W) before extending | stretching. Rth can be reduced when the ratio L / W (referred to as aspect ratio) of longitudinal stretching to lateral stretching is more than 2 and 50 or less (long span stretching), and Rth when the aspect ratio is 0.01 to 0.3 (short span stretching). Can be increased. In the present invention, any of long span stretching, short span stretching, and stretching between these regions (intermediate stretching = L / W exceeds 0.3 and 2 or less) may be used. Span stretching or short span stretching is preferred. Furthermore, when it is desired to obtain a high Rth, short span stretching is preferred, and when it is desired to obtain a low Rth, a long span stretching can be appropriately selected and employed.

(1 long span stretching)
The film is stretched as it is stretched. At this time, the film is reduced in thickness and width in order to reduce the volume change. At this time, shrinkage in the width direction is limited by friction between the nip roll and the film. For this reason, when the nip roll interval is increased, shrinkage in the width direction is facilitated, and thickness reduction can be suppressed. When the thickness reduction is large, the same effect as that in which the film is compressed in the thickness direction is obtained, and molecular orientation advances in the film plane and Rth tends to increase. On the contrary, when the aspect ratio is large and the thickness reduction is small, Rth hardly appears and low Rth can be realized.
Furthermore, if the aspect ratio is long, the uniformity in the width direction can be improved. This is due to the following reason.
• The film tends to shrink in the width direction as it is stretched. At the central portion in the width direction, both sides thereof also try to contract in the width direction, so that it becomes a tug of war and cannot be contracted freely.
-On the other hand, the film width direction end part is in a tug-of-war state only with one side, and can contract relatively freely.
-The difference in shrinkage behavior associated with the stretching between both ends and the central portion becomes stretching unevenness in the width direction.
Due to such non-uniformity between both ends and the center, retardation in the width direction and axial deviation (orientation angle distribution of slow axis) occur. On the other hand, since long span stretching is performed slowly between two long nip rolls, the uniformity of these non-uniformities (the molecular orientation becomes uniform) proceeds during stretching. On the other hand, in normal longitudinal stretching (aspect ratio = more than 0.3 and less than 2), such homogenization does not occur.

The aspect ratio exceeds 2 and is preferably 50 or less, more preferably 3 to 40, and still more preferably 4 to 20. The stretching temperature is preferably (Tg-5 ° C) to (Tg + 100) ° C, more preferably (Tg) to (Tg + 50) ° C, and still more preferably (Tg + 5) to (Tg + 30) ° C. The draw ratio is preferably 1.05 to 3 times, more preferably 1.05 to 1.7 times, and still more preferably 1.05 to 1.4 times. Such long span stretching may be performed in multiple stages with three or more pairs of nip rolls as long as the longest aspect ratio is within the above range.
Such long span stretching may be performed by heating the film between two pairs of nip rolls separated by a predetermined distance. The heating method is a heater heating method (infrared heater, halogen heater, panel heater, etc. above or below the film). Or heating by radiant heat) or a zone heating method (heating in a zone in which hot air or the like is blown and adjusted to a predetermined temperature) may be used. In the present invention, the zone heating method is preferable from the viewpoint of uniformity of the stretching temperature. At this time, the nip roll may be installed in the stretching zone or out of the zone, but it is preferably out of the zone in order to prevent the film and the nip roll from sticking. It is also preferable to preheat the film before such stretching, and the preheating temperature is (Tg-80) ° C to (Tg + 100) ° C.

(1 short span stretching)
The aspect ratio (L / W) is preferably more than 0.01 and less than 0.3, more preferably 0.03.
Longitudinal stretching (short span stretching) is performed at ˜0.25, more preferably 0.05˜0.2. By performing stretching at an aspect ratio (L / W) in such a range, neck-in (shrinkage in a direction orthogonal to stretching accompanying stretching) can be reduced. The width and thickness are reduced to compensate for stretching in the stretching direction. However, in such short span stretching, width shrinkage is suppressed and thickness reduction proceeds preferentially. As a result, it becomes compressed in the thickness direction, and the orientation (plane orientation) in the thickness direction advances. As a result, Rth, which is a measure of anisotropy in the thickness direction, tends to increase. On the other hand, conventionally, the aspect ratio (L / W) is generally about 1 (0.7 to 1.5). This is usually done by installing a heater for heating between the nip rolls, but if the L / W is too large, the film cannot be heated uniformly with the heater and uneven stretching tends to occur. If the L / W is too small, the heater is stretched. This is because it is difficult to install and cannot be heated sufficiently.
The short span stretching described above can be carried out by changing the transport speed between two or more pairs of nip rolls, but unlike the normal roll arrangement, the two pairs of nip rolls are arranged obliquely (the rotation axes of the front and rear nip rolls are shifted up and down). This can be achieved. Accordingly, since a heater for heating cannot be installed between the nip rolls, it is preferable to raise the temperature of the film by flowing a heating medium in the nip rolls. Further, it is also preferable to provide a preheating roll in which a heating medium is flowed inside before the entrance side nip roll and heat the film before stretching.
The stretching temperature is preferably (Tg-5 ° C) to (Tg + 100) ° C, more preferably (Tg) to (Tg + 50) ° C, and still more preferably (Tg + 5) to (Tg + 30) ° C. The preheating temperature is preferably (Tg−80) ° C. to (Tg + 100) ° C.

(Lateral stretching)
The transverse stretching can be performed using a tenter. That is, the film is stretched by holding both ends in the width direction with clips and widening the film in the lateral direction. At this time, the stretching temperature can be controlled by sending wind at a desired temperature into the tenter. The stretching temperature is (Tg-10) ° C. to (Tg + 60) ° C.
Is preferable, (Tg-5) ° C to (Tg + 45) ° C is more preferable, and Tg to (Tg + 30).
More preferably.
By performing preheating before stretching and heat setting after stretching, the Re and Rth distribution after stretching can be reduced, and the variation in orientation angle associated with bowing can be reduced. Either preheating or heat setting may be performed, but both are more preferable. These preheating and heat setting are preferably performed by holding with a clip, that is, preferably performed continuously with stretching.
Preheating is preferably performed at a temperature higher than the stretching temperature by 1 ° C to 50 ° C, more preferably 2 ° C to 40 ° C, and even more preferably 3 ° C to 30 ° C. The preheating time is preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, and still more preferably 10 seconds to 2 minutes. During preheating, it is preferable to keep the width of the tenter substantially constant. Here, “substantially” refers to ± 10% of the width of the unstretched film, for example.
The heat setting is preferably 1 to 50 ° C., more preferably 2 to 40 ° C., and further preferably 3 to 30 ° C. lower than the stretching temperature. More preferably, it is less than the stretching temperature and less than Tg. The preheating time is preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, and still more preferably 10 seconds to 2 minutes. During the heat setting, it is preferable to keep the width of the tenter substantially constant. Here, “substantially” refers to 0% (the same width as the tenter width after stretching) to −10% (shrinking by 10% from the tenter width after stretching = reduced width) of the tenter width after stretching. If the width is wider than the stretched width, residual strain is likely to occur in the film, and it is not preferable because it is likely to increase the variation with time of Re and Rth.
Thus, it is preferable that the heat setting temperature <the stretching temperature <the preheating temperature.
The reason why the variation in orientation angle and Re and Rth can be reduced by such preheating and heat setting is as follows. That is, as shown in FIG. 3A, when preheating temperature = stretching temperature = preheating temperature, the film is stretched in the width direction and tends to be thinned in the orthogonal direction (longitudinal direction) (neck-in). For this reason, the film before and after transverse stretching is pulled and stress is generated. However, both ends in the width direction are fixed by chucks and are not easily deformed by stress, and the central portion in the width direction is easily deformed. As a result, the stress caused by the neck-in is deformed into a bow shape and bowing occurs. As a result, in-plane Re and Rth unevenness and distribution of orientation axes occur. Therefore, by setting the heat setting temperature <stretching temperature <preheating temperature, the temperature on the preheating side (before stretching) is increased and the temperature on the heat treatment (after stretching) is decreased. It occurs during preheating and is less likely to occur during heat treatment (after stretching). As a result, bowing after stretching can be suppressed.

By such stretching, the variations in the width direction and the longitudinal direction of Re and Rth can both be preferably 5% or less, more preferably 4% or less, and still more preferably 3% or less. Further, the orientation angle can be preferably 90 ° ± 5 ° or less or 0 ° ± 5 ° or less, more preferably 90 ° ± 3 ° or less or 0 ° ± 3 ° or less, and further preferably 90 ° ± 1 °. Or 0 ° ± 1 ° or less.
The present invention is characterized in that such an effect can be achieved even at high speed, preferably 2
Even if it is 0 m / min or more, more preferably 25 m / min or more, and even more preferably 30 m / min or more, a remarkable effect appears.

(Relaxation treatment)
Furthermore, dimensional stability can be improved by performing relaxation treatment after these stretching. The thermal relaxation is preferably performed after longitudinal stretching, either after lateral stretching, or after both, and more preferably after lateral stretching. The relaxation treatment may be performed online continuously after stretching, or may be performed offline after winding after stretching.
The relaxation treatment is preferably performed at a temperature of (Tg-30) ° C to (Tg + 30) ° C, more preferably (Tg-30) ° C to (Tg + 20) ° C, and even more preferably (Tg-15) ° C to (Tg + 10) ° C. , Preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, even more preferably 10 seconds to 2 minutes, preferably 0.1 kg / m to 20 kg / m, more preferably 1 kg / m to 16 kg / m More preferably, it is carried out while transporting at a tension of 2 kg / m to 12 kg / m.

<Polarizing plate>
The polarizing plate of the present invention includes a polarizer and the cyclic olefin resin film of the present invention.
Since the film of the present invention has good film optical properties and good film elastic modulus, it is preferably used as a protective film for polarizing plates. Moreover, since the film of the present invention has a good surface shape and less unevenness when the film surface state is observed under polarizing plate crossed Nicols, it is suitable for a protective film for polarizing plate. The polarizing plate is formed by laminating and laminating a protective film on at least one surface of the polarizer. A conventionally known polarizer can be used. For example, a hydrophilic polymer film such as a polyvinyl alcohol film is treated with a dichroic dye such as iodine and stretched. The lamination of the cyclic olefin resin film and the polarizer is not particularly limited, but can be performed with an adhesive made of an aqueous solution of a water-soluble polymer. The water-soluble polymer adhesive is preferably a completely saponified polyvinyl alcohol aqueous solution.
In addition, the polarizing plate using the film of the present invention has little variation in the slow axis distribution, and can provide a liquid crystal display device with good display performance. Further, when the film of the present invention is a preferred embodiment having a wide width, when a polarizing plate is produced by laminating with a polarizer using the film of the present invention, two so-called polarizing plates are taken in the film width direction. Therefore, the manufacturing cost of the polarizing plate can be reduced. Moreover, when it is the aspect which (sigma) 600 of a film width direction and (sigma) -600 are also favorable, the performance of the polarizing plate which performed 2 picking and 3 picking can also be improved.

<Liquid crystal display device>
The liquid crystal display device of the present invention includes a cyclic olefin resin film or the polarizing plate of the present invention.
The film of the present invention is a protective film for polarizing plate / polarizer / protective film for polarizing plate / liquid crystal cell / film of the present invention / polarizer / protective film for polarizing plate, or protective film for polarizing plate / polarizer / It can use preferably by the structure of the film of this invention / liquid crystal cell / protective film for polarizing plates of this invention / polarizer / protective film for polarizing plates. In particular, by bonding to a liquid crystal cell such as a TN type, VA type, or OCB type, a liquid crystal display device having excellent viewing angle, low visibility with little coloration, and excellent in-plane uniformity is provided. can do. In addition, the polarizing plate using the film of the present invention has little deterioration under high temperature and high humidity conditions and can maintain stable performance for a long period of time, that is, the liquid crystal display device of the present invention has good durability.

  The present invention will be described more specifically with reference to the following examples. The materials, amounts used, ratios, processing details, processing procedures, and the like shown in the following examples can be changed as appropriate without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below.

[Cyclic olefin resin]
The following cyclic olefin-based resins P-1 to P-5 and C-1 were prepared.

<Synthesis of Cyclic Olefin Resin P-1>
100 parts by mass of purified toluene and 100 parts by mass of norbornene carboxylic acid methyl ester were charged into a reaction kettle. Next, ethyl hexanoate-Ni dissolved in toluene 25 mmol% (based on monomer), tri (pentafluorophenyl) boron 0.225 mol% (based on monomer), and triethylaluminium 0.25 mol% (based on monomer) dissolved in toluene Was put into the reaction kettle. The reaction was allowed to proceed for 18 hours at room temperature with stirring. After completion of the reaction, the reaction mixture was put into an excess of etal to form a polymer precipitate. The cyclic olefin resin P-1 obtained by purifying the precipitate was vacuum dried at 65 ° C. for 24 hours.
The obtained polymer was dissolved in tetrahydrofuran and measured for molecular weight by gel permeation chromatography. The number average molecular weight in terms of polystyrene was 79,000 and the weight average molecular weight was 205,000. The refractive index of the obtained polymer measured by Abbe's refractometer was 1.52, and Tg was 250 ° C.

<Synthesis of Cyclic Olefin Resin P-2>
6-Methyl-1,4,5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene in 100 parts by mass, 15% by weight cyclohexane solution of triethylaluminum as a polymerization catalyst 10 Part by mass, 5 parts by mass of triethylamine, and 10 parts by mass of a 20% by mass cyclohexane solution of titanium tetrachloride were added to perform ring-opening polymerization in cyclohexane, and the resulting ring-opening polymer was hydrogenated with a nickel catalyst. A polymer solution was obtained. This polymer solution was coagulated in isopropyl alcohol and dried to obtain a powdery resin P-2. The number average molecular weight of this resin was 40,000, the hydrogenation rate was 99.8% or more, and the Tg was 139 ° C.

P-3: ARTON D5023 (manufactured by JSR Corporation), Tg 170 ° C.
P-4: ZF14 (manufactured by Optes Co., Ltd., film product), Tg 139 ° C.
P-5: TOPAS 6013 (manufactured by Polyplastics Co., Ltd.), Tg 134 ° C.
C-1: Cellulose acetate (acetyl substitution degree = 2.85)

[Examples 1 to 16 and Comparative Examples 1 to 3]
The cyclic olefin resin films of Examples 1 to 16 and Comparative Examples 1 to 3 were produced by the solution casting method as follows.

(Solution casting method)
(1) Dope Preparation <1-1> Cyclic Olefin Resin Solution The following composition is put into a mixing tank, stirred to dissolve each component, further heated at 90 ° C. for about 10 minutes, and then filtered with an average pore size of 34 μm. And it filtered with the sintered metal filter with an average hole diameter of 10 micrometers.
――――――――――――――――――――――――――――――――――
Cyclic olefin resin solution ――――――――――――――――――――――――――――――――――
Cyclic olefin resin listed in Table 1 100.0 parts by mass Dichloromethane 276.0 parts by mass Methanol 34.0 parts by mass ――――――――――――――――――――――― ――――――――――

<1-2> Matting Agent Dispersion Solution Next, the following composition containing the cyclic olefin resin solution prepared by the above method was charged into a dispersing machine to prepare a matting agent dispersion.
――――――――――――――――――――――――――――――――――――
Matting agent dispersion ――――――――――――――――――――――――――――――――――――
2.0 parts by mass of silica particles having an average particle diameter of 16 nm (aerosil R972, manufactured by Nippon Aerosil Co., Ltd.)
Dichloromethane 75.4 parts by mass Methanol 4.6 parts by mass Cyclic olefin resin solution 10.3 parts by mass ――――――――――――――――――――――――――― ――――――――

<1-3> Additive-containing cyclic olefin-based resin solution 94.6 parts by mass of the cyclic olefin-based resin solution prepared by the above method and 1.3 parts by mass of the matting agent dispersion are charged into a mixing tank and heated. It stirred and melt | dissolved and each additive (plasticizer, retardation expression agent) of following Table 1 was added, and the additive containing cyclic olefin resin solution was prepared. The additive amount (parts by mass) of the additives listed in Table 1 below is an amount with respect to 100 parts by mass of the cyclic olefin resin. In Table 1, when the additive column is blank, it means that no additive is added.
Each additive will be described below.

(Retardation expression agent)
Compound R-1 is a compound having the following structure.

(Plasticizer)
Compounds PA-1 and PC-1 are the following compounds.
PA-1: Condensate composed of ethylene glycol / succinic acid (1/1 molar ratio) (number average molecular weight 1100)
PC-1: UMM1001 (acrylic polymer, manufactured by Soken Chemical Co., Ltd.)

  In addition, the cellulose acylate and various additives used as the dope raw material were previously dried at 120 ° C. for 2 hours using a silo manufactured by Nara Machinery Co., Ltd.

Each additive-containing cyclic olefin resin solution (dope) produced above was cast on a film production line with the flow rate adjusted so that the completed cyclic olefin resin film had a desired film thickness. The dope was dried on a belt until self-supporting, and then peeled off as a film and introduced into a tenter. At this time, the temperature of the dope was 35 ° C., the residence time on the belt was 5 seconds, and the film after peeling was 0 ° C. when measured with a radial film surface thermometer (IT540S, manufactured by Horiba, Ltd.). there were.
The volatile content of the film at the time of introduction into the tenter was 5% to 15% lower than the volatile content of the stripped samples. Volatiles at the time of stripping were 30% to 50%. The temperature in the tenter was 140 ° C., and the film was conveyed while gripping the film in the width direction. Immediately after leaving the tenter, the roll was conveyed with a tension of 25 N / m, and further dried at 140 ° C. and wound up.

  Thus, a cyclic olefin resin film having a width of 1500 mm and a film thickness shown in Table 1 was obtained.

(Film optical properties)
For the cyclic olefin-based resin film produced above, in-plane retardation Re was measured by the above-described method using a three-dimensional birefringence measurement at a wavelength of 550 nm using an automatic birefringence meter KOBRA-WR (manufactured by Oji Scientific Instruments). The retardation Rth in the film thickness direction was obtained by measuring Re at different tilt angles.
Further, the obtained value of Rth (unit: nm) was divided by the film thickness (unit: μm) of each film to obtain Rth (Rth / d) per film thickness.
Further, Rth (10%) and Rth (80%) were measured in an environment of 25 ° C. and 10% RH and 25 ° C. and 80% RH, and ΔRth was obtained from the following formula (5).
ΔRth (RH) = | Rth (10%) − Rth (80%) | (5)
These results are shown in Table 1 below together with the film thickness d.

[Examples 18-20, 26-28 and Comparative Examples 5-6]
Using the components shown in Table 2 below, cyclic olefin-based resin films of Examples 18 to 20 and Comparative Examples 5 to 6 were produced by the melt film forming method as follows. The cyclic olefin resins shown in Table 2 are the same as those described above.

(Melting method)
100 parts by mass of a cyclic olefin-based resin that has been dried at 80 ° C. for 6 hours (water content 200 ppm), 1.2 parts by mass of an ultraviolet absorber LA-31 (manufactured by ADEKA), Irganox 1010 (Ciba Specialty Chemicals) 0.5 parts by mass, ADK STAB PEP-36 (manufactured by ADEKA) 0.08 parts by mass, Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd.) 0.2 parts by mass, silicon dioxide fine particles (AEROSIL-R972V) 0. 4 parts by mass was further dried with mixing in a vacuum nauter mixer at 80 ° C. and 1 Torr for 3 hours. Furthermore, the obtained mixture was melt-mixed at 235 ° C. using a twin-screw extruder and pelletized.

The cyclic olefin resin film was formed and stretched as follows.
Pellets (water content 50 ppm) were melt extruded from a T die onto a first cooling roll having a surface temperature of 100 ° C. at a melting temperature of 245 ° C. using a single-screw extruder, with an initial film thickness of 80 μm and a width of 1.36 m. 3000 m was obtained at a length of 30 m / min. At this time, the film was pressed on the first cooling roll with an elastic touch roll having a 2 mm thick metal surface.
The obtained film was stretched at 1500 ° C. in the film forming direction at 195 ° C. by a stretching machine using a difference in peripheral speed of the rolls according to the stretching temperature shown in Table 2 (Tg is the glass transition temperature of the cyclic olefin resin) and the stretching ratio. Stretched at% / min. Next, in a tenter having a preheating zone, a stretching zone, a holding zone, and a cooling zone (there is also a neutral zone for ensuring thermal insulation between the zones), a stretching speed of 400 at a lateral direction at 145 ° C. The film was stretched at% / min, then cooled to 30 ° C., released from the clip, and both ends were excised by 100 mm slitting. Thereafter, a knurling process is performed on both end portions and the central portion of the film at a temperature of 270 ° C. and a pressing pressure of 0.04 MPa with a width of 15 mm to form a concavo-convex portion, and the thickness shown in Table 2 is 2.08 m wide and 4000 m long. The raw material of the olefin resin film roll was obtained. At this time, the knurling height was 15% for the knurling at both ends and 25% for the knurling at the center with respect to the film thickness.

[Examples 21 to 25 and Comparative Example 4]
The stretching temperature (Tg is the glass transition temperature of the cyclic olefin resin) and the stretching ratio shown in Table 2 using the stretching machine used in Example 18 and the like for the above P-4 (film form) as the cyclic olefin resin. The cyclic olefin resin films of Examples 21 to 25 and Comparative Example 4 were produced in the same manner as in Example 18 and the like.

(Film optical properties)
For the cyclic olefin-based resin film produced above, in-plane retardation Re was measured by the above-described method using a three-dimensional birefringence measurement at a wavelength of 550 nm using an automatic birefringence meter KOBRA-WR (manufactured by Oji Scientific Instruments). The retardation Rth in the film thickness direction was obtained by measuring Re at different tilt angles.
Further, the obtained value of Rth (unit: nm) was divided by the film thickness (unit: μm) of each film to obtain Rth (Rth / d) per film thickness.
Further, Rth (10%) and Rth (80%) were measured in an environment of 25 ° C. and 10% RH and 25 ° C. and 80% RH, and ΔRth was obtained from the following formula (5).
ΔRth (RH) = | Rth (10%) − Rth (80%) | (5)
These results are shown in Table 2 below together with the film thickness d.

(Panel performance)
[Production of polarizing plate]
A polarizer was produced by adsorbing iodine to a stretched polyvinyl alcohol film.
The corona-treated cyclic olefin resin film of Example 1 was attached to one side of the polarizer using a polyvinyl alcohol-based adhesive. A commercially available cellulose triacetate film (Fujitac TD80UF, manufactured by Fuji Film Co., Ltd.) is subjected to saponification treatment, and using a polyvinyl alcohol-based adhesive, the polarized light on the side opposite to the side on which the prepared film of Example 1 is attached A cellulose triacetate film after saponification treatment was attached to the surface of the child.
At this time, the transmission axis of the polarizer and the slow axis of the prepared film of Example 1 were arranged in parallel. Further, the transmission axis of the polarizer and the slow axis of the commercially available cellulose triacetate film were arranged so as to be orthogonal to each other.
Thus, the polarizing plate of the present invention was produced.
A good polarizing plate could be obtained without any problem in handling and workability.

Claims (8)

The cyclic olefin resin film which contains cyclic olefin resin and satisfy | fills following formula (1)-(4).
| Re | ≦ 4nm (1)
50 nm ≦ Rth ≦ 300 nm (2)
10 μm ≦ d ≦ 70 μm (3)
1 × 10 ⁻³ ≦ Rth / d ≦ 1 × 10 ⁻² (4)
In the formula, Re is the retardation value in the in-plane direction of the film, Rth is the retardation value in the thickness direction of the film, and d is the thickness of the film. The cyclic olefin resin film according to claim 1, wherein ΔRth (RH) represented by the following formula (4) is less than 10.
ΔRth (RH) = | Rth (10%) − Rth (80%) | (5)
In the formula, Rth (10%) is the Rth of the film measured in an environment of 25 ° C. and 10% RH, and Rth (80%) is the Rth of the film measured in an environment of 25 ° C. and 80% RH.   The cyclic olefin resin film according to claim 1 or 2, wherein the cyclic olefin resin film is formed by a solution casting method.   The cyclic olefin resin film according to claim 3, wherein the cyclic olefin resin film contains a plasticizer or a retardation developer.   The cyclic olefin resin film according to claim 1 or 2, wherein the cyclic olefin resin film is formed by a melt film forming method. 6. The cyclic olefin-based resin film is formed by a biaxial stretching process, and the MD stretching ratio in the film longitudinal direction and the TD stretching ratio in the direction orthogonal to the longitudinal direction satisfy the following formula (6). The cyclic olefin-based resin film described in 1.
0.8 ≦ MD stretch ratio / TD stretch ratio ≦ 1.2 (6)   The polarizing plate using the cyclic olefin resin film as described in any one of Claims 1-6.   The liquid crystal display device using the cyclic olefin resin film as described in any one of Claims 1-6, or the polarizing plate of Claim 7.