JP2008068427A - Method for producing cyclic polyolefin film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To continuously produce a cyclic polyolefin film without occurrence of a scratch or a wrinkle. <P>SOLUTION: Dope 24 is made to flow continuously on a traveling casting band 82 to form a cast film 24a, and it is peeled off while it contains water. The film 62 is dried while being stretched in the width direction by a tenter 64. Both side end parts of the film 62 are knurled by holding both the side end parts of the film 62 by a pair of rollers 65 having unevenness on the peripheral surfaces which is installed in a conveyance way on the downstream side of the tenter. The knurled film 62, after being dried in a drying chamber 69, is taken up by a winding roll 107. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a cyclic polyolefin film.

  A liquid crystal display device has a polarizing plate and a liquid crystal cell, and the demand for display has been increasing in recent years. Under such circumstances, various liquid crystal display devices have been proposed, and examples thereof include a TN mode TFT liquid crystal display device. As described in Patent Document 1, this is because the display performance is improved as compared with the conventional liquid crystal display devices by further providing a retardation film between the polarizing plate and the liquid crystal cell. And as for a polarizing plate, a protective film is distribute | arranged on both surfaces of the polarizing film, and as this protective film, a cellulose acetate film, especially a cellulose triacetate film are common. Also, a cellulose acetate film such as cellulose triacetate is often used as the retardation film. This is because the cellulose acetate film is excellent in toughness, flame retardancy, and optical isotropy, and the cellulose triacetate (TAC) film is particularly excellent in the above properties.

  However, even the TN mode TFT liquid crystal display device as described above has a problem that the polarizer is deteriorated due to the cellulose acetate film, and the display performance of the liquid crystal display device is deteriorated with time. This is because the cellulose acetate film is a highly hygroscopic and moisture permeable material.

  Thus, a cyclic polyolefin film has attracted attention as an alternative to the cellulose acetate film, and many cyclic polyolefin retardation films have been proposed (see, for example, Patent Documents 2 to 5). This is because the cyclic polyolefin film has a feature of being more hygroscopic and moisture permeable than cellulose acylate.

Examples of the production method of the cyclic polyolefin film include a melt film formation method and a solution film formation method, but the latter is superior in order to exhibit better performance as an optical film. As is well known, the solution casting method as a continuous manufacturing method is a method in which a dope, in which a solid component such as a polymer is dissolved in a solvent, is caused to flow out of a casting die and cast on a traveling support. In this method, a cast film is formed, and the cast film is peeled off from the support and dried.
JP-A-8-50206 JP 2003-121927 A JP 2004-126026 A JP 2002-114825 A International Publication No. 04/049011 Pamphlet

  However, in the above Patent Documents 2 to 5, there is no specific description about the film manufacturing method, and there is almost no description about the continuous manufacturing method, which does not help mass production. As for the solution casting method, many techniques using a cellulose acylate such as cellulose acetate as a film have been proposed, but this cannot be applied to a cyclic polyolefin. This is because the physical properties and chemical properties of cellulose acylate and cyclic polyolefin are greatly different from each other. The physical characteristics are, for example, strength and elastic modulus, and the chemical characteristics are, for example, thermal characteristics, solubility in liquid, viscosity, and the like.

Among the above properties, especially for the elastic modulus, both have greatly different properties, and the cellulose acetate film has an elastic modulus of about 400 × 9.8 (N / mm ² ) among cellulose acylates, Most cyclic polyolefin films have an elastic modulus of 300 × 9.8 N / mm ² or less. The elastic modulus is a factor deeply related to the setting of conditions for various processes of film production. When the elastic modulus changes, most of the process conditions must be newly set. If it is not set again, wrinkles, creases, scratches, etc. will occur frequently on the film. This tendency is particularly noticeable in the step of drying while supporting the film with a roller having a smooth peripheral surface. However, it is very difficult to reset all the conditions for solution casting.

  Therefore, an object of the present invention is to provide a simple method for continuously forming a cyclic polyolefin having an elastic modulus considerably smaller than that of cellulose acylate without causing wrinkles, creases, scratches and the like.

  The method for producing a cyclic polyolefin film of the present invention includes a casting film forming step of flowing a dope containing a cyclic polyolefin and a solvent from a casting die to form a casting film on a traveling support, and a casting film. The wet film is dried and stretched in the width direction while the both sides of the wet film are held by the holding means and conveyed while being peeled off from the support as a wet film containing a solvent. A stretching process, a knurling imparting process for imparting knurling to the side edge of the wet film by bringing the wet film subjected to the stretching process into contact with an uneven roller having irregularities on the peripheral surface, and a wet film subjected to the knurling process Are dried by a drying means while being supported by a smooth roller having a smooth peripheral surface, and a cyclic polyolefin film is obtained by a drying process, and a ring subjected to the drying process. It is configured as characterized by having a winding step of winding the polyolefin film.

The effect of the present invention is great when the elastic modulus of the cyclic polyolefin film is 100 × 9.8 N / mm ² or more and 300 × 9.8 N / mm ² or less. When the knurling is applied, the solvent content of the wet film is preferably 5% by mass or more and 30% by mass or less, and the knurling is preferably provided on both sides of the wet film. It is preferable that the height of the knurling unevenness is determined according to the thickness of the cyclic polyolefin film determined in advance.

  A cyclic polyolefin having an elastic modulus much smaller than that of cellulose acylate can be easily and continuously formed into a film without causing wrinkles, creases and scratches.

  Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the embodiments described here. First, the cyclic polyolefin in the present invention will be described, and then the method for producing the film will be described.

[Cyclic polyolefin and fine particles]
The cyclic polyolefin in the present invention is a polymer having a cyclic olefin structure. Examples thereof include (1) a norbornene-based polymer, (2) a monocyclic olefin polymer, and (3) a cyclic conjugated diene. Polymers, (4) vinyl alicyclic hydrocarbon polymers, and hydrides of (1) to (4). Preferred polymers for the present invention are addition (co) polymer cyclic polyolefins containing at least one repeating unit represented by the following general formula (II), and at least repeating units represented by the general formula (I). An addition (co) polymer cyclic polyolefin further comprising one or more. Further, a ring-opening (co) polymer containing at least one cyclic repeating unit represented by the general formula (III) can also be suitably used.

式中、ｍは０〜４の整数を表す。Ｒ^１ 〜Ｒ^６ は、水素原子または炭素数１〜１０の炭化水素基、Ｘ^１ 〜Ｘ^３ 、Ｙ^１ 〜Ｙ^３ は水素原子、炭素数１〜１０の炭化水素基、ハロゲン原子、ハロゲン原子で置換された炭素数１〜１０の炭化水素基、−（ＣＨ_２ ）_ｎ ＣＯＯＲ^１１、−（ＣＨ_２ ）_ｎ ＯＣＯＲ^１２、−（ＣＨ_２ ）_ｎ ＮＣＯ、−（ＣＨ_２ ）_ｎ ＮＯ_２ 、−（ＣＨ_２ ）_ｎ ＣＮ、−（ＣＨ_２ ）_ｎ ＣＯＮＲ^１３Ｒ^１４、−（ＣＨ_２ ）_ｎ ＮＲ^１３Ｒ^１４、−（ＣＨ_２ ）_ｎ ＯＺ、−（ＣＨ_２ ）_ｎ Ｗ、または、Ｘ^１ とＹ^１ あるいはＸ^２ とＹ^２ あるいはＸ^３ とＹ^３ から構成された（−ＣＯ）_２ Ｏ、（−ＣＯ）_２ ＮＲ^１５を示す。なお、Ｒ^１１〜Ｒ^１５は、水素原子、炭素数１〜２０の炭化水素基、Ｚは炭化水素基またはハロゲンで置換された炭化水素基、ＷはＳｉＲ^１６ _ｐ Ｄ_３−ｐ （Ｒ^１６は炭素数１〜１０の炭化水素基、Ｄはハロゲン原子−ＯＣＯＲ^１６または−ＯＲ^１６、ｐは０〜３の整数を示す）、ｎは０〜１０の整数を示す。

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 hydrogen atoms, a hydrocarbon group having 1 to 10 carbon atoms, a halogen atom, a halogen atom in substituted hydrocarbon group having 1 to 10 carbon ^{_{atoms, - (CH 2) n COOR}} 11, - (CH 2) n OCOR 12, - (CH 2) n NCO, - (CH 2) n NO 2, - (CH ₂ ) _n CN, — (CH ₂ ) _n CONR ¹³ R ¹⁴ , — (CH ₂ ) _n NR ¹³ R ¹⁴ , — (CH ₂ ) _n OZ, — (CH ₂ ) _n W, or X ¹ composed of Y ¹ or ^{X 2} and ^{Y 2} or ^{X 3} and _{^{Y 3 (-CO) 2 O,}} - a (CO) 2 ^{NR 15} shown. R ^{11 to} R ¹⁵ are a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, Z is a hydrocarbon group or a hydrocarbon group substituted with halogen, and W is SiR ¹⁶ _p D _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), in-plane retardation The expression of (Re) can be increased. A film having a large Re development property can have a large Re value by stretching the film during the film production process.

  Norbornene-based addition (co) polymers are disclosed in JP-A-10-7732, JP-T 2002-504184, US2004229157A1, WO2004 / 070463A1, and the like. It can be obtained by addition polymerization. If necessary, it can also be obtained by addition polymerization of a norbornene-based polycyclic unsaturated compound and the following diene compound. Examples of the diene compound include conjugated dienes, non-conjugated dienes, and linear diene compounds. Examples of the conjugated diene compound include ethylene, propylene, butene, butadiene, and isoprene. An example of the non-conjugated diene compound is ethylidene norbornene. Examples of the linear diene compound include acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate, and vinyl chloride. The norbornene-based addition (co) polymer is marketed by Mitsui Chemicals, Inc. under the trade name of Apel, and there are a plurality of grades having different glass transition temperatures (Tg). They are APL8008T (Tg70 degreeC), APL6013T (Tg125 degreeC), APL6015T (Tg145 degreeC) etc., for example. In addition, pellets such as TOPAS 8007, 6013, 6015, etc. are sold as products by Polyplastics Co., Ltd. Further, Appear 3000 is sold by Ferrania.

Norbornene polymer hydrides are disclosed in JP-A-1-240517, JP-A-7-196736, JP-A-60-26024, JP-A-62-19807, JP-A-2003-115767, JP-A-2004-309799. As disclosed in various publications such as No. 1, etc., it is prepared by addition polymerization or metathesis ring-opening polymerization of a polycyclic unsaturated compound 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. . 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. In the present invention, the above can be used as a film.

[solvent]
The solvent is not particularly limited as long as the cyclic polyolefin is soluble. Preferable examples include chlorinated compounds such as dichloromethane and chloroform, and compounds selected from chain hydrocarbons having 3 to 12 carbon atoms, cyclic hydrocarbons, aromatic hydrocarbons, esters, ketones, and ethers. The ester, ketone and ether may have a cyclic structure. Examples of chain hydrocarbons having 3 to 12 carbon atoms include hexane, octane, isooctane, decane, and the like. Examples of cyclic hydrocarbons having 3 to 12 carbon atoms include cyclopentane, cyclohexane and derivatives thereof. Examples of the aromatic hydrocarbon having 3 to 12 carbon atoms include benzene, toluene, xylene and the like. Examples of the ester having 3 to 12 carbon atoms include ethyl formate, propyl formate, pentyl formate, methyl acetate, ethyl acetate, and pentyl acetate. Examples of ketones having 3 to 12 carbon atoms include acetone, methyl ethyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and methylcyclohexanone. 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 the organic solvent having two or more kinds of functional groups include 2-ethoxyethyl acetate, 2-methoxyethanol, and 2-butoxyethanol. The preferable boiling point of the organic solvent is 35 ° C. or more and 150 ° C. or less. In the present invention, a mixture of two or more compounds can be used as a solvent for adjusting dope physical properties such as drying property and viscosity. Further, when the mixture is used as a solvent, the mixture is a so-called poor solvent. May be added.

  The poor solvent to be added can be appropriately selected depending on the polymer type to be used. For example, when a chlorinated organic solvent is used as the good solvent, alcohol can be preferably used. The alcohol may have any of a linear, branched, and cyclic structure, and among them, a saturated aliphatic hydrocarbon is preferable. The alcohol may be any of primary to tertiary. Examples of the alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, t-butanol, 1-pentanol, 2-methyl-2-butanol and cyclohexanol. In addition, as alcohol, a fluorine-type alcohol is also used. Examples thereof include 2-fluoroethanol, 2,2,2-trifluoroethanol, 2,2,3,3-tetrafluoro-1-propanol and the like. Of the poor solvents, monohydric alcohols are particularly effective because they have an effect of reducing peeling resistance. Particularly preferred alcohols vary depending on the good solvent to be selected, but considering the drying load, alcohols having a boiling point of 120 ° C. or lower are preferred, monohydric alcohols having 1 to 6 carbon atoms are more preferred, and alcohols having 1 to 4 carbon atoms Can be particularly preferably used. A particularly preferred mixed solvent for preparing a dope of cyclic polyolefin is a combination in which dichloromethane is the main solvent and one or more alcohols selected from methanol, ethanol, propanol, isopropanol, or butanol are poor solvents.

[Additives and other film components]
Various additives and other film components can be added to the dope of the cyclic polyolefin depending on the application. Additives include (1) degradation inhibitor, (2) UV inhibitor, (3) retardation (optical anisotropy) regulator, (4) peeling accelerator, (5) plasticizer, (6) red Examples include an external absorbent and (7) fine particles. The additive may be solid or oily, that is, it is not particularly limited by its melting point or boiling point. For example, it is possible to use a mixture of ultraviolet absorbing materials having melting points of 20 ° C. or lower and 20 ° C. or higher, and a mixture of deterioration inhibitors. Infrared absorbents (infrared absorbing dyes) are described, for example, in JP-A No. 2001-194522, and they can also be used in the present invention. The timing of addition may be any step in the cyclic polyolefin dope production process, or may be added by adding an additive addition process at the end of the dope production process. The addition amount of each additive is not particularly limited as long as a desired function is exhibited. Moreover, when manufacturing the cyclic polyolefin film of a multilayer structure, you may change the kind and addition amount of an additive for every layer.

(1) Deterioration inhibitor In this invention, a well-known deterioration inhibitor (antioxidant) can be added to dope, and there exist phenol type and hydroquinone type antioxidant. Examples include 2,6-di-tert-butyl, 4-methylphenol, 4,4′-thiobis- (6-tert-butyl-3-methylphenol), 1,1′-bis (4-hydroxyphenyl) ) Cyclohexane, 2,2′-methylenebis (4-ethyl-6-tert-butylphenol), 2,5-di-tert-butylhydroquinone, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl) -4-hydroxyphenyl) propionate. Other examples include tris (4-methoxy-3,5-diphenyl) phosphite, tris (nonylphenyl) phosphite, tris (2,4-di-t-butylphenyl) phosphite, bis (2,6 Phosphorous antioxidants such as -di-t-butyl-4-methylphenyl) pentaerythritol diphosphite and bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite. As for the addition amount of antioxidant, 0.05-5.0 mass parts is preferable with respect to 100 mass parts of cyclic polyolefin.

(2) Ultraviolet absorber When using the film obtained for a polarizing plate or with a liquid crystal, it is preferable that an ultraviolet absorber is added to dope from a viewpoint of prevention of deterioration of a polarizing plate, a liquid crystal, etc. As the ultraviolet absorber, those which are excellent in the ability to absorb ultraviolet rays having a wavelength of 370 nm or less and have little absorption of visible light having a wavelength of 400 nm or more are preferable from the viewpoint of good liquid crystal display properties. Specific examples of ultraviolet absorbers preferably used include hindered phenol compounds, oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. .

  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 -Chlorbenzotriazole, 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, based on the cyclic polyolefin.

(3) Retardation regulator A compound having at least two aromatic rings can be used as a retardation regulator so that the film exhibits a predetermined retardation value. When using a retardation modifier, it is preferably used in a proportion in the range of 0.05 to 20 parts by mass, and used in a proportion in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the cyclic polyolefin. More preferably, it is more preferably used in a proportion in the range of 0.2 to 5 parts by mass, and most preferably in a proportion in the range of 0.5 to 2 parts by mass. Two or more retardation modifiers may be used in combination. The retardation regulator is preferably a compound having maximum absorption in the wavelength region of 250 to 400 nm, and preferably a compound having substantially no absorption ability in the visible region.

  The “aromatic ring” of the retardation modifier 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, benzene ring, furan ring, thiophene ring, pyrrole ring, oxazole ring, thiazole ring, imidazole ring, triazole ring, pyridine ring, pyrimidine ring, pyrazine ring and 1,3,5-triazine ring 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 aromatic rings contained in the retardation modifier is preferably 2 to 20, more preferably 2 to 12, still more preferably 2 to 8, and most preferably 2 to 6. preferable. The bond relationship between two aromatic rings can be classified into three types: (a) when a condensed ring is formed, (b) when directly linked by a single bond, and (c) when linked via a linking group. It can be a compound having any binding relationship. Needless to say, spiro bonds cannot be formed due to the bonding of aromatic rings.

  Examples of the condensed ring of (a), that is, a condensed ring of two or more aromatic rings include indene ring, naphthalene ring, azulene ring, fluorene ring, phenanthrene ring, anthracene ring, acenaphthylene ring, biphenylene ring, 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 Yo Thianthrene ring, and the like. Of these, naphthalene ring, azulene ring, indole ring, benzoxazole ring, benzothiazole ring, benzimidazole ring, benzotriazole ring and quinoline ring are preferable.

  The single bond (b) is preferably a bond between carbon atoms of two aromatic rings. Two aromatic rings may be bonded with 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 one that bonds between the carbon atoms of two aromatic rings, similarly to the single bond in (b) above. 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 linking groups 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 above aromatic ring and linking group may have a substituent. Examples of the substituent include a halogen atom (F, Cl, Br, I), hydroxyl group, carboxyl group, cyano group, amino group, nitro group, sulfo group, carbamoyl group, sulfamoyl group, ureido group, alkyl group, Alkenyl group, alkynyl group, aliphatic acyl group, aliphatic acyloxy group, alkoxy group, alkoxycarbonyl group, alkoxycarbonylamino group, alkylthio group, alkylsulfonyl group, aliphatic amide group, aliphatic sulfonamide group, aliphatic substituted amino group 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, and examples of the substituent include a hydroxy group, a carboxy group, an alkoxy group, and an alkyl-substituted amino group. Examples of alkyl groups (including substituted alkyl groups) include groups such as methyl, ethyl, n-butyl, n-hexyl, 2-hydroxyethyl, 4-carboxybutyl, 2-methoxyethyl and 2-diethylaminoethyl. 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 among the chain alkenyl groups. The alkenyl group may further contain a substituent. Examples of alkenyl groups are vinyl, allyl and 1-hexenyl. 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 among the chain alkynyl groups. The alkynyl group may further contain a substituent. Examples of alkynyl groups are ethynyl, 1-butynyl and 1-hexynyl.

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

  The alkylthio group preferably has 1 to 12 carbon atoms. Examples of the alkylthio group include methylthio, ethylthio and octylthio groups. 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 an acetamide group. The number of carbon atoms of the aliphatic sulfonamide group is preferably 1-8. Examples of the aliphatic sulfonamide group include methanesulfonamide, butanesulfonamide, and n-octanesulfonamide groups. The number of carbon atoms of the aliphatic substituted amino group is preferably 1-10. Examples of the aliphatic substituted amino group include dimethylamino, diethylamino and 2-carboxyethylamino groups.

  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 non-aromatic heterocyclic groups include piperidino and morpholino groups. The molecular weight of the retardation regulator is preferably 300 to 800.

  As a retardation regulator, a rod-shaped compound having a linear molecular structure can be preferably used in addition to a compound containing a 1,3,5-triazine ring. The linear molecular structure means that the molecular structure of the rod-like compound is linear in the most thermodynamically stable structure. The most thermodynamically stable structure can be obtained by crystal structure analysis or molecular orbital calculation. For example, molecular orbital calculation can be performed using molecular orbital calculation software (eg, WinMOPAC2000, manufactured by Fujitsu Limited) to obtain a molecular structure that minimizes the heat of formation of a compound. The linear molecular structure means that the angle formed by the main chain is 140 degrees or more in the thermodynamically most stable structure obtained by calculation as described above.

  As the rod-shaped compound having at least two aromatic rings, a compound represented by the following general formula (IV) is preferable.

Formula ^{(IV): Ar 1 -L 1} -Ar 2
In the general formula (IV), Ar ¹ and Ar ² are each independently an aromatic group. The aromatic group includes an aryl group (aromatic hydrocarbon group), a substituted aryl group, an aromatic heterocyclic group, and a substituted aromatic heterocyclic group. An aryl group and a substituted aryl group are more preferable than an aromatic heterocyclic group and a substituted aromatic heterocyclic group. The heterocycle of the aromatic heterocyclic group is generally unsaturated. 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 a hetero atom, a nitrogen atom, an oxygen atom or a sulfur atom is preferable, and a nitrogen atom or a sulfur atom is more preferable. As the aromatic ring of the aromatic group, a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, an oxazole ring, a thiazole ring, an imidazole ring, a triazole ring, a pyridine ring, a pyrimidine ring and a pyrazine ring are preferable, and a benzene ring is particularly preferable. .

In the general formula (IV), L ¹ is a divalent linking group selected from an alkylene group, an alkenylene group, an alkynylene group, —O—, —CO—, and a combination thereof. The alkylene group may have a cyclic structure. As the cyclic alkylene group, cyclohexylene is preferable, and 1,4-cyclohexylene is particularly preferable. As the chain alkylene group, a linear alkylene group is more preferable than a branched alkylene group. The number of carbon atoms of the alkylene group is preferably 1-20, more preferably 1-15, still more preferably 1-10, still more preferably 1-8, and most preferably 1-6. It is.

The alkenylene group and the alkynylene group preferably have a chain structure rather than a cyclic structure, and more preferably have a linear structure rather than a branched chain structure. The alkenylene group and the alkynylene group preferably have 2 to 10 carbon atoms, more preferably 2 to 8, more preferably 2 to 6, still more preferably 2 to 4, and most preferably 2. (Vinylene or ethynylene). The arylene group preferably has 6 to 20 carbon atoms, more preferably 6 to 16, and still more preferably 6 to 12. In the molecular structure of the general formula (IV), the angle formed by L ¹ and Ar ¹ and Ar ² sandwiching it is preferably 140 ° or more.

  As the rod-like compound, a compound represented by the following general formula (V) is more preferable.

Formula ^{(V): Ar 1 -L 2} -X-L 3 -Ar 2
In the general formula (V), Ar ¹ and Ar ² are each independently an aromatic group. The definition and examples of the aromatic group are the same as those of Ar ¹ and Ar ^{2 in} the general formula (IV).

In the general formula (V), L ² and L ³ are each independently a divalent linking group selected from an alkylene group, —O—, —CO—, and a group consisting of a combination thereof. The alkylene group preferably has a chain structure rather than a cyclic structure, and more preferably has a linear structure rather than a branched chain structure. The number of carbon atoms of the alkylene group is preferably 1 to 10, more preferably 1 to 8, still more preferably 1 to 6, still more preferably 1 to 4, and 1 or 2 (that is, Most preferred is methylene or ethylene. L ² and L ³ are particularly preferably —O—CO— or —CO—O—. In the general formula (V), X is 1,4-cyclohexylene, vinylene or ethynylene. Two or more rod-shaped compounds having a maximum absorption wavelength (λmax) shorter than 250 nm in the ultraviolet absorption spectrum of the solution may be used in combination. The addition amount of the retardation enhancer is preferably 0.1 to 30% by mass, and more preferably 0.5 to 20% by mass with respect to the cyclic polyolefin.

(4) Peeling accelerator As an addition accelerator for reducing the peeling resistance of the cyclic polyolefin film, many so-called surfactants have been found to have remarkable effects. Preferred addition accelerators include phosphate ester surfactants, carboxylic acid or carboxylate surfactants, sulfonic acid or sulfonate surfactants, and sulfate ester surfactants. A fluorine-based surfactant in which part of the hydrogen atoms bonded to the hydrocarbon chain of the surfactant is substituted with fluorine atoms is also effective. Examples of the peeling accelerator are given below.

_{RZ-1 C 8 H 17 O} -P (= O) - (OH) 2
_{RZ-2 C 12 H 25 O} -P (= O) - (OK) 2
_{RZ-3 C 12 H 25 OCH} 2 CH 2 O-P (= O) - (OK) 2
_{RZ-4 C 15 H 31 (} OCH 2 CH 2) 5 O-P (= O) - (OK) 2
_{RZ-5 {C 12 H 25} O (CH 2 CH 2 O) 5} 2 -P (= O) -OH
_{RZ-6 {C 18 H 35} (OCH 2 CH 2) 8 O} 2 -P (= O) -ONH 4
_{RZ-7 (t-C 4} H 9) 3 -C 6 H 2 -OCH 2 CH 2 O-P (= O) - (OK) 2
_{RZ-8 (iso-C 9} H 19 -C 6 H 4 -O- (CH 2 CH 2 O) 5 -P (= O) - (OK) (OH)
RZ-9 C ₁₂ H ₂₅ SO ₃ Na
RZ-10 C ₁₂ H ₂₅ OSO ₃ Na
RZ-11 C ₁₇ H ₃₃ COOH
RZ-12 C ₁₇ H ₃₃ COOH · N (CH ₂ CH ₂ OH) _{3
RZ-13 iso-C 8 H} 17 -C 6 H 4 -O- (CH 2 CH 2 O) 3 - (CH 2) 2 SO 3 Na
_{RZ-14 (iso-C 9} H 19) 2 C 6 H 3 -O- (CH 2 CH 2 O) 3 - (CH 2) 4 SO 3 Na
RZ-15 sodium triisopropyl naphthalene sulfonate RZ-16 sodium tri-t-butyl naphthalene sulfonate RZ-17 C ₁₇ H ₃₃ CON (CH ₃ ) CH ₂ CH ₂ SO ₃ Na
_{RZ-18 C 12 H 25 -C} 6 H 4 SO 3 · NH 4
The addition amount of the release agent is preferably 0.05 to 5% by mass, more preferably 0.1 to 2% by mass, and most preferably 0.1 to 0.5% by mass with respect to the cyclic polyolefin.

(5) Plasticizer Generally, the cyclic polyolefin is poor in flexibility as compared with cellulose acetate, and when the film is made into a film and subjected to bending stress or shear stress, the film is likely to be cracked. Further, when the obtained film is processed for use in an optical product, if it is cut or the like, the cut portion is likely to crack, and chips are likely to be generated. The generated chips contaminated the film and caused optical defects in the optical product. Therefore, in order to improve this problem, a plasticizer can be added to the dope. Specific examples of plasticizers include phthalate esters, trimellitic esters, aliphatic dibasic esters, orthophosphate esters, acetate esters, polyester epoxidized esters, ricinoleate esters, polyolefins And polyethylene glycol-based compounds.

  The plasticizer that can be used is preferably a compound that is liquid at normal temperature and pressure and has a boiling point of 200 ° C. or higher. As specific compound names, the following can be exemplified.

  Examples of the aliphatic dibasic acid ester system include dioctyl adipate (230 ° C./760 mmHg), dibutyl adipate (145 ° C./4 mmHg), di-2-ethylhexyl adipate (335 ° C./760 mmHg), dibutyl diglycol adipate (230-240). ° C / 2mmHg), di-2-ethylhexyl azelate (220-245 ° C / 4mmHg), di-2-ethylhexyl sebacate (377 ° C / 760mmHg) and the like. Examples of the phthalic acid ester system include diethyl phthalate (298 ° C./760 mmHg), diheptyl phthalate (235 to 245 ° C./10 mm Hg), di-n-octyl phthalate (210 ° C./760 mm Hg), diisodecyl phthalate (420 ° C./760 mm Hg). ) And the like. In addition, as polyolefins, paraffin waxes such as normal paraffin, isoparaffin, cycloparaffin (average molecular weight 330 to 600, melting point 45 to 80 ° C.), liquid paraffin (JIS standards K2231 ISOVG8, VG15, VG32, VG68, VG100 etc.), paraffin pellets (melting point 56-58 ° C., 58-60 ° C., 60-62 ° C., etc.), chlorinated paraffin, low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight polyisobutene, hydrogenated polybutadiene, hydrogenated polyisoprene. , Squalane and the like.

  The addition amount of the plasticizer is 0.5 to 40.0% by mass, preferably 1.0% to 30.0% by mass, more preferably 3.0% to 20.0% by mass with respect to the cyclic polyolefin. is there. When the addition amount of the plasticizer is less than 0.5% by mass, the plastic effect is insufficient and the processability is not improved. On the other hand, when the amount is more than 40% by mass, the plasticizer may be separated and eluted after a long period of time, resulting in optical unevenness and contamination of other parts.

(7) Fine particles By adding fine particles to the above various cyclic polyolefins, it is possible to reduce the stress applied to the film when handling the film by lowering the dynamic friction coefficient of the film surface than when not adding. The fine particles that can be used in the present invention are not particularly limited, and fine particles of organic or inorganic compounds can be used.

  Examples of inorganic compounds that can be used as fine particles include silicon-containing compounds, silicon dioxide, titanium oxide, zinc oxide, aluminum oxide, barium oxide, zirconium oxide, strongtium oxide, antimony oxide, tin oxide, tin oxide / antimony, Calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate, calcium phosphate and the like are preferable, and silicon-containing inorganic compounds and metal oxides are more preferable. From the viewpoint that the turbidity of the film can be reduced, silicon dioxide is particularly preferable. As the fine particles of silicon dioxide, for example, commercially available products with trade names such as Aerosil R972, R974, R812, 200, 300, R202, OX50, TT600 (all of which are manufactured by Nippon Aerosil Co., Ltd.) can be used. As the fine particles of zirconium oxide, for example, commercially available products having trade names such as Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.) can be used.

  Examples of organic compounds that can be used as fine particles include polytetrafluoroethylene, cellulose acetate, polystyrene, polymethyl methacrylate, polypropyl methacrylate, polymethyl acrylate, polyethylene carbonate, and starch. These pulverized and classified products can also be used. In addition, a polymer compound synthesized by a suspension polymerization method, a polymer compound made spherical by a spray drying method, a dispersion method, or the like can also be used.

  The primary average particle diameter of these fine particles is preferably 1 nm to 20000 nm, more preferably 1 to 10000 nm, still more preferably 2 to 1000 nm, and particularly preferably 5 from the viewpoint of keeping the haze of the film low. ~ 500 nm. The primary average particle diameter of the fine particles can be obtained from the average particle diameter of the particles by a transmission electron microscope. The purchased fine particles are often agglomerated and are preferably preliminarily dispersed by a known method before use. The secondary particle diameter is preferably 200 to 1500 nm by dispersion, and more preferably 300 to 1000 nm.

  The amount of fine particles added is preferably 0.01 to 0.3 parts by weight, more preferably 0.05 to 0.2 parts by weight, and most preferably 0.08 to 0.12 parts by weight with respect to 100 parts by weight of the cyclic polyolefin. .

  The preferable haze range of the cyclic polyolefin film to which fine particles are added is 2.0% or less, more preferably 1.2% or less, and particularly preferably 0.5% or less. A preferable dynamic friction coefficient of the cyclic polyolefin film to which fine particles are added is 0.8 or less, and particularly preferably 0.5 or less. The dynamic friction coefficient can be measured using a steel ball in accordance with a method specified by JIS or ASTM. The haze can be measured using a 1001DP type haze meter manufactured by Nippon Denshoku Industries Co., Ltd.

[Dope production]
FIG. 1 shows a dope manufacturing facility. However, the present invention is not limited to the dope manufacturing apparatus and method shown here. The dope production facility 10 includes a solvent tank 11 for storing a solvent, a polymer, that is, a cyclic polyolefin, and a hopper 12 for temporarily opening and sending out a lower outlet (not shown) if necessary, An additive tank 15 for storing the additive, a mixing tank 17 for mixing the solvent, the polymer, and the additive to form a mixed liquid 16, a heating device 18 for heating the mixed liquid 16, and a heating A temperature regulator 21 for adjusting the temperature of the liquid mixture 16, a filtration device 22 for filtering the liquid mixture 16 from the temperature regulator 21, and a flash device 26 for adjusting the concentration of the dope 24 from the filtration device 22. And a filtering device 27 for filtering the dope 24 whose concentration has been adjusted. The dope manufacturing facility 10 further includes a recovery device 28 for recovering the solvent and a regeneration device 29 for regenerating the recovered solvent. The dope manufacturing facility 10 is connected to a film manufacturing facility 33 via a stock tank 32. In addition, although the valves 36-38 for adjusting the amount of liquid feeding and the pumps 41 and 42 for liquid feeding are provided in the dope manufacturing equipment 10, about the increase / decrease in the position and number where these are arrange | positioned It is changed appropriately.

  When the dope manufacturing facility 10 is used, the dope 24 is manufactured by the following method. By opening the valve 37, the solvent is sent from the solvent tank 11 to the mixing tank 17. Next, the polymer is fed from the hopper 12 into the mixing tank 17. At this time, the polymer may be continuously fed to the mixing tank 17 by a sending unit that continuously measures and feeds, or is intermittently connected to the mixing tank 17 by a sending unit that measures and sends a predetermined amount. May be sent in. In addition, the required amount of the additive solution is sent from the additive tank 15 to the mixing tank 17 by opening and closing the valve 36.

  In addition to the method of feeding the additive as a solution, when the additive is liquid at room temperature, the additive can be fed into the mixing tank 17 in its liquid state. Further, when the additive is solid, a method of feeding it into the mixing tank 17 using a hopper or the like is also possible. When a plurality of types of additives are added, a solution in which a plurality of types of additives are dissolved can be placed in the additive tank 15. Alternatively, it is also possible to use a plurality of additive tanks and put a solution in which the additive is dissolved in each of them and send them to the mixing tank 17 through independent pipes.

  The order in which the solvent, polymer, and additive are added to the mixing tank 17 is not particularly limited. Moreover, an additive is not necessarily limited to mixing a polymer and a solvent in the mixing tank 17, and may be mixed with the mixture of a polymer and a solvent by an in-line mixing system etc. in a next process.

  The mixing tank 17 is provided with a jacket 46 that covers the outer surface thereof and is supplied with a heat transfer medium therein, a first stirrer 48 that is rotated by a motor 47, and a second stirrer 52 that is rotated by a motor 51. The temperature of the mixing tank 17 is adjusted by a heat transfer medium flowing into the jacket 46, and a preferable temperature range is -10 ° C to 55 ° C. By appropriately selecting the type of the first stirrer 48 and the second stirrer 52, the mixed liquid 16 in which the polymer is swollen with the solvent is obtained. The first stirrer 48 preferably includes an anchor blade on a rotating shaft member, and the second stirrer 52 is preferably a dissolver type eccentric stirrer.

  Next, the liquid mixture 16 is sent to the heating device 18 by the pump 41. The heating device 18 is preferably a jacketed tube having a tube main body (not shown) and a jacket for passing a heat transfer medium between the tube main body, and further pressurizing the mixed liquid 16. It is preferable to have a part (not shown). By using such a heating device 18, the solid content in the mixed solution 16 can be effectively and efficiently dissolved under heating conditions or pressure heating conditions. Hereinafter, such a method of dissolving a solid component in a solvent by heating is referred to as a heating dissolution method. In the heat dissolution method, it is preferable to heat the mixed liquid 16 to a temperature equal to or higher than the boiling point of the solvent, or pressurize and heat to a critical point of the solvent at a high temperature and a high pressure. When dichloromethane is used as the main solvent, many cyclic polyolefins can be dissolved at a heating temperature of 20 ° C to 100 ° C.

  Note that the solid component may be dissolved in a solvent by a cooling dissolution method instead of the heating dissolution method. The cooling dissolution method is a method of proceeding dissolution while cooling the mixed solution 16 so that the temperature of the mixed solution 16 is maintained or lower. In the cooling dissolution method, it is preferable that the mixed liquid 16 in which the polymer is swollen with a solvent is cooled to a temperature of −20 ° C. to −100 ° C. and then heated to 20 ° C. to 100 ° C. The polymer can be sufficiently dissolved in the solvent by the heating dissolution method or the cooling dissolution method as described above.

  The mixed liquid 16 is cooled to approximately room temperature by the temperature controller 21, and then filtered by the filtration device 22 to remove foreign matters such as impurities and aggregates, thereby obtaining a dope 24. The filter used in the filtration device 22 preferably has an average pore diameter of 50 μm or less.

  The dope 24 after filtration is sent to the stock tank 32 by the valve 38 and once stored, and then used for the production of a film.

  By the way, as described above, the method of once swelling the solid component and then dissolving it to make the dope increases the time required for the dope production as the concentration of the polymer in the solution increases, and in terms of production efficiency. May be a problem. In such a case, it is preferable to once make a dope having a concentration lower than the target concentration and then carry out a concentration step to achieve the target concentration.

  The concentration method is not particularly limited. For example, a heated low-concentration dope is blown into the container from the nozzle, and the solvent is flash evaporated between the nozzle and the inner wall of the container. Is extracted from the container, and a dope having a high concentration is extracted from the bottom of the container (for example, described in US Pat. No. 2,410,612, US Pat. No. 2,858,229, US Pat. No. 4,414,341, US Pat. No. 4,504,355, etc.) Can be applied.

  In the concentration step by flash evaporation of the present embodiment, the dope 24 filtered by the filtration device 22 is sent to the flash device 26 by the valve 38, and a part of the solvent of the dope 24 is evaporated by the flash device 26. Can be concentrated. The concentrated dope 24 is extracted from the flash device 26 by the pump 42 and sent to the filtration device 27. The temperature of the dope 24 during filtration is preferably 0 ° C to 200 ° C. The dope 24 from which foreign matter has been removed by the filtration device 27 is sent to the stock tank 32 and once stored, and then used for film production. In addition, since the concentrated dope 24 may contain bubbles, it is preferable to carry out a bubble removal process before sending it to the filtration device 27. As the bubble removal method, for example, various known methods such as an ultrasonic irradiation method for irradiating the dope 24 with ultrasonic waves are applied.

  Further, the solvent gas generated by the flash evaporation in the flash device 26 is condensed by the recovery device 28 having a condenser (not shown) and recovered as a liquid. The recovered solvent is regenerated and reused as a solvent for dope production by the regenerator 29. Such collection and recycling have advantages in terms of manufacturing costs and are effective in preventing adverse effects on the human body and the environment because they are implemented in a closed system.

  By the above manufacturing method, the dope 24 whose polymer concentration is 5 mass% or more and 40 mass% or less can be manufactured. The polymer concentration is more preferably in the range of 15% by mass to 30% by mass, and further preferably in the range of 16% by mass to 25% by mass. The mass of the additive is preferably in the range of 1 or more and 20 or less, assuming that the mass of the entire solid content in the dope is 100.

  The dope viscosity is preferably in the range of 1 Pa · s to 500 Pa · s at 25 ° C., more preferably in the range of 5 Pa · s to 200 Pa · s. The viscosity can be measured by the following method. 1 mL of a sample sampled from the dope is placed in a rheometer (CLS 500) and measured using a Steel Cone (both manufactured by TA Instruments) having a diameter of 4 cm / 2 °. The sample is kept warm in advance until the temperature becomes constant at the measurement start temperature, and the measurement starts thereafter.

[Production of film]
The equipment and method for producing a cyclic polyolefin film will be described. FIG. 2 is a schematic view of the film manufacturing facility 33, and FIG. 3 is a schematic view of the vicinity of the casting die. However, the present invention is not limited to the film manufacturing method and equipment as shown here. In the film manufacturing facility 33, a filtration device 61 that removes foreign matters from the dope 24 sent from the stock tank 32, and a dope 24 filtered by the filtration device 61 are cast to form a cyclic polyolefin film (hereinafter simply referred to as a film). 62), a tenter 64 that holds both side ends of the film 62 and dries while transporting the film 62, an edge-cutting device 67 that separates the both-side ends of the film 62, and an ear-cutting device 67. A pair of rollers 65 embossed on both ends of the film 62 after passing through to give a knurling, a drying chamber 69 that dries while transporting the film 62 over a plurality of rollers 68 having a smooth peripheral surface, and a film A cooling chamber 71 for cooling 62, a static eliminating device 72 for reducing the charge amount of the film 62, and a winding chamber 7 for winding the film 62. Door is provided.

  The stock tank 32 is provided with a stirrer 78 that is rotated by a motor 77 to stir the dope 24. The stock tank 32 is connected to the filtration device 61 via the pump 80.

  The filter of the filtration device 61 preferably has an absolute filtration accuracy of 0.1 μm to 100 μm, and more preferably 0.5 μm to 25 μm. The thickness of the filter is preferably 0.1 mm to 10 mm, and more preferably 0.2 mm to 2 mm. When such a filter is used, the filtration pressure is preferably 1.6 MPa or less, more preferably 1.3 MPa or less, further preferably 1.0 MPa or less, and particularly preferably 0.6 MPa or less. Examples of the material for the filter include known materials such as glass fibers, cellulose fibers, filter paper, fluorine-based polymers such as polytetrafluoroethylene, ceramics, metals, and the like.

The casting chamber 63 includes a casting die 81 that flows out of the dope 24, and a casting band 82 as a traveling support. The casting die 81 is preferably a coat hanger type die. As a material of the casting die 81, precipitation hardening type stainless steel is preferable, and its thermal expansion coefficient is preferably 2 × 10 ⁻⁵ (° C. ⁻¹ ) or less. And it has almost the same corrosion resistance as SUS316 in the forced corrosion test with electrolyte aqueous solution, and even if it is immersed in a mixed solution of dichloromethane, methanol and water for 3 months, pitting (opening) occurs at the gas-liquid interface. Those having corrosion resistance that do not occur are preferred. The casting die 81 is preferably produced by grinding a material that has passed for one month or more after casting, whereby the dope 24 uniformly flows inside the casting die 81, and the flow described later. It is possible to prevent streaks or the like from occurring in the spread film 24b. The so-called wetted surface in contact with the dope 24 of the casting die 81 preferably has a finishing accuracy of 1 μm or less in terms of surface roughness and a straightness of 1 μm / m or less in any direction. The clearance of the slit of the casting die 81 can be adjusted in the range of 0.5 mm to 3.5 mm by automatic adjustment.

  The chamfer radius R of the corner portion of the liquid contact portion at the tip of the lip of the casting die 81 is constant and 5 μm or more and 50 μm or less over the entire width of the casting die 81. If the chamfer radius R is less than 5 μm, streaks or the like may occur in the casting beat 24 a, and if it is larger than 50 μm, it becomes difficult to make the lip clearance uniform and the thickness of the casting film 24 b becomes non-uniform. Sometimes. The arithmetic average roughness Ra of the tip lip is preferably 0.013 μm or more and 1.6 μm or less. If Ra is less than 0.013, ultra-precise machining is required, resulting in high costs. On the other hand, if it exceeds 1.6 μm, streaks or the like may enter the casting beat 24a.

  The width of the casting die 81 is not particularly limited, but is preferably about 1.01 to 1.3 times the width of the film 62 as the final product. In addition, a temperature controller that controls the temperature of the casting die 81 is preferably attached to the casting die 81 so that the temperature of the dope 24 during film formation is maintained at a predetermined temperature. Furthermore, it is more preferable that the casting die 81 is provided with a plurality of thickness adjusting bolts (heat bolts) at predetermined intervals in the width direction, and an automatic thickness adjusting mechanism that automatically adjusts the slit gap by the heat bolt. . Based on a program set in advance, a profile is set according to the amount of pump 81 (preferably a high precision gear pump), and the heat bolt is adjusted according to the profile. In order to precisely control the dope feed amount, the pump 80 is preferably a high-precision gear pump. Further, in the film manufacturing facility 33, for example, a non-contact type thickness measuring machine such as an infrared thickness gauge is arranged, and an automatic program for adjusting the thickness to the automatic thickness adjusting mechanism is obtained by an adjustment program based on the thickness profile and a detection result by the thickness measuring machine. Feedback control may be performed. It is preferable that the difference in thickness at any two positions excluding both ends of the film 62 as a product is within 1 μm.

More preferably, a cured film is formed at the lip end of the casting die 81. A method for forming the cured film is not particularly limited, and examples thereof include ceramic coating, hard chrome plating, and a nitriding method. When ceramics are used as the cured film, those that can be ground, have low porosity, are not brittle, have good corrosion resistance, and have no affinity and adhesion to the dope 24 are preferable. Specific examples include tungsten carbide (WC), Al ₂ O ₃ , TiN, Cr ₂ O _{3 and the} like. Among them, WC is particularly preferable. The WC coating can be performed by a thermal spraying method.

  In order to prevent the dope 24 from locally drying and solidifying at the lip tip of the casting die 81, a liquid supply device (not shown) for supplying a liquid to the lip tip is preferably attached in the vicinity of the lip tip. . Since the liquid to be supplied is preferably excellent in affinity with the dope 24, the same liquid as the solvent component of the dope 24 is preferable. The position where the liquid is supplied is preferably a peripheral portion of a three-phase contact line formed by both ends of the casting bead, both ends of the lip tip, and the outside air. The flow rate of the supplied liquid is preferably 0.1 mL / min to 1.0 mL / min for each side. Thereby, it is possible to prevent foreign matters, for example, solid components precipitated from the dope 24 and those mixed in the casting bead from the outside from being mixed in the casting film 24b. In addition, as a pump which supplies a liquid, it is preferable to use a pump with a pulsation rate of 5% or less.

  The casting band 82 below the casting die 81 is stretched around the rotating rollers 85 and 86 and is continuously conveyed by the drive rotation of at least one of the rotating rollers.

  The width of the casting band 82 is not particularly limited, but it is preferable to use a casting band having a range of 1.05 to 1.5 times the casting width of the dope 24. The length is preferably 60 m to 120 m, the thickness is 1 mm to 2 mm, and the surface is preferably polished so that the surface roughness is 0.05 μm or less. The thickness unevenness is preferably 0.5% or less.

  The material of the casting band 82 is not particularly limited, but is preferably made of stainless steel, and more preferably made of SUS316 so as to have sufficient corrosion resistance and strength.

  The rotating rollers 85 and 86 are preferably provided with a heat transfer medium circulating device 87 for supplying the heat transfer medium to the rotating rollers 85 and 86 and controlling the surface temperature of the rollers. The surface temperature is set to a predetermined value. In this embodiment, a flow path (not shown) through which the heat transfer medium passes is formed in the rotary rollers 85 and 86, and the temperature of the rotary rollers 85 and 86 is maintained at a predetermined value by controlling the temperature of the heat transfer medium. Is done. The surface temperature of the casting band 82 is appropriately set according to the type of solvent, the type of solid component, the concentration of the dope 24, and the like.

A rotating drum (not shown) can be used as a support instead of the rotating rollers 85 and 86 and the casting band 82. In this case, it is preferable that the rotation speed fluctuation range is 0.2% or less of the set speed and the rotation speed can be rotated with high accuracy to some extent. The rotating drum preferably has an average surface roughness of 0.01 μm or less, and preferably has a surface subjected to a hard chrome plating treatment or the like. Thereby, sufficient hardness and durability can be improved. In addition, it is preferable that the surface defects of the rotating drum, the casting band 82, and the rotating rollers 85 and 86 are suppressed to a minimum. Specifically, there is no pinhole of 30 μm or more, and the number of pinholes of 10 μm or more and less than 30 μm is 1 / m ² or less, and the number of pinholes of less than 10 μm is preferably ² / m ² or less.

  In the vicinity of the casting die 81, a decompression chamber 90 may be provided to control the pressure on the upstream side in the traveling direction of the casting band 82 of the casting beat 24a formed from the casting die 81 to the casting band 82. preferable.

  In the vicinity of the band 53, in order to suppress the blow ducts 91 to 93 that blow wind to evaporate the solvent of the casting film 24b and the wind that disturbs the shape of the casting film 24b against the casting film 24b. The wind shielding plate 94 is provided.

  The casting chamber 63 is provided with a temperature control device 97 for keeping the internal temperature at a predetermined value and a condenser for condensing and recovering the volatilized organic solvent, that is, a condenser 98. A recovery device 99 for recovering the condensed and liquefied organic solvent is provided outside the casting chamber 63.

  A blower 102 is provided in the transition portion 101 downstream of the casting chamber 63. The ear clip device 67 is provided with a crusher 103 for finely cutting the side edge scraps of the cut film 62. One roller of the roller pair 65 is provided with a shift mechanism 66 that detects a pressing pressure with the other roller and displaces one of the rollers so as to obtain a predetermined pressing pressure value.

  The drying chamber 69 is provided with an adsorption recovery device 106 for adsorbing and recovering the solvent gas generated by evaporation from the film 62. The cooling chamber 71 is provided downstream of the drying chamber 69, but a humidity control chamber (not shown) for adjusting the water content of the film 62 may be provided between the drying chamber 69 and the cooling chamber 71. Good. The static eliminator 72 is a forced static eliminator such as a static eliminator, and the charged voltage of the film 62 is set within a predetermined range. The static eliminator 72 is not limited to the downstream side of the cooling chamber 71. Inside the take-up chamber 76, a take-up roll 107 for taking up the film 62 and a press roller 108 for controlling the tension during the take-up are provided.

  Next, an example of a method for producing the film 62 using the film production equipment 33 as described above will be described below. The dope 24 is always made uniform by the rotation of the stirrer 78. Various additives can be appropriately mixed in the dope 24 during the stirring.

  The dope 24 is sent to the stock tank 32, and solid matter precipitation and aggregation are suppressed by stirring until it is cast. And the foreign material of a size more than a predetermined particle size and a gel-like foreign material are removed by filtration with the filtration apparatus 61. FIG.

The dope 24 is cast by being discharged or discharged onto a casting band 82 that travels from the casting die 81. The relative position of the rotary roller 85 and the rotary roller 86 and / or the rotational speed of at least one of them is adjusted so that the tension generated in the casting band 82 is 10 ⁴ N / m to 10 ⁵ N / m. Further, the relative speed difference between the casting band 82 and the rotating rollers 85 and 86 is set to 0.01 m / min or less. It is preferable that the speed fluctuation of the casting band 82 is 0.5% or less, and the meandering in the width direction that occurs when the casting band 82 makes one round is 1.5 mm or less. In order to suppress this meandering, a detector (not shown) that detects the positions of both ends of the casting band 82 and a position adjuster (not shown) that adjusts the position of the casting band 82 according to the detection data from this detector. It is more preferable to provide feedback control of the position of the casting band 82. Further, it is preferable that the position fluctuation in the vertical direction associated with the rotation of the rotary roller 85 is within 200 μm for the casting band 82 immediately below the casting die 81. In addition, the temperature of the casting chamber 63 is preferably set to −10 ° C. to 57 ° C. by the temperature control device 97. The solvent evaporated in the casting chamber 63 is recovered by the recovery device 99 and then regenerated and reused as a solvent for dope production. The casting speed is preferably constant in the range of 10 m / min to 200 m / min.

  A casting beat 24 a is formed from the casting die 81 to the casting band 82, and a casting film 24 b is formed on the casting band 82. In order to stabilize the state of the casting beat 24a, the pressure reduction chamber 90 is preferably controlled so that the pressure in the upstream area with respect to the bead 24b becomes a predetermined pressure. The reduced pressure value is preferably constant in the range of −2000 Pa to −10 Pa from the downstream area with respect to the bead. It is preferable to attach a jacket (not shown) to the decompression chamber 90 so that the internal temperature is maintained at a predetermined temperature. In order to keep the shape of the casting bead desired, it is preferable to attach a suction device (not shown) to the edge portion of the casting die 81 to suck both sides of the bead. This edge suction air volume is 1 L / min. ~ 100 L / min. It is preferable that it is the range of these.

  The discharge speed of the dope 24 from the casting die 81 is preferably 3 m / min or more, more preferably 5 m / min or more. By setting the discharge speed to 3 m / min or more, the residence of the dope 24 at the discharge port of the casting die is suppressed. Further, the lower limit of the discharge speed is not particularly limited, but if it is less than 3 m / min, productivity is lowered, which is not preferable. The discharge speed of the dope 27 can be obtained by dividing the dope flow rate by the area of the discharge port 43a. Further, the discharge speed of the dope 27 can be controlled by adjusting the clearance of the discharge port 43a or by increasing or decreasing the dope flow rate.

  In order to suppress the occurrence of defects such as unevenness in the thickness of the casting beat 24a and the occurrence of burrs, the drying speed of the casting bead is preferably as small as possible, and most preferably zero. The adjustment of the drying speed is performed by adjusting the temperature of the casting die 81, the prescription of the dope 24 (for example, containing an additive), the internal temperature of the casting chamber 63, the air temperature and humidity from the air ducts 91 to 93, and the like. This can be done easily.

  It is preferable that the solid content concentration on the surface of the casting beat 24a immediately after coming out of the casting die 81 is 16% by mass or more and 25% by mass or less. When the solid content concentration is less than 16% by mass, the viscosity of the casting bead 24a is too low and the elongation stress of the casting bead 24a is too low, so that the casting beat 24a adheres to the lip tips 81b and 81c. In some cases, there is a problem that it is difficult to peel off. On the other hand, if it exceeds 25% by mass, there may be a problem that the state of the sharkskin surface formed by the discharge port 81a is deteriorated. The sharkskin surface is the surface of the casting bead 69a that is in the form of a husk. Since the solid content concentration on the surface of the casting beat 24a immediately after coming out of the casting die 81 is difficult to measure on-line on the production line, the solid content concentration of the dope 24 fed to the casting die 81 is determined. You may consider this value.

  After the casting film 24b has self-supporting properties, it is peeled off from the casting band 82 while being supported by the peeling roller 109.

  The film 62 containing the solvent is supported by a plurality of rollers and conveyed through the crossing portion 101 and then sent to the tenter 64. In at least any one of the crossover part 101 and the tenter 64, at least one direction of the casting direction and the width direction of the film 62 is 100.5% to 300% of the dimension before stretching. It is preferable to stretch. In the crossing portion 101, draw tension can be applied to the film 62 by making the rotation speed of the downstream roller faster than the rotation speed of the upstream roller. Moreover, in the crossover part 101, the drying air of desired temperature is sent to the film 62 vicinity from the air blower 102, or is directly sprayed on the film 62, and the drying of the film 62 is advanced. At this time, the temperature of the drying air is preferably 20 ° C to 250 ° C.

  The film 62 sent to the tenter 64 is dried while its both ends are held and conveyed by holding means such as a clip 64a. A pin may be used instead of the clip, and the film may be pierced and held by the pin. Moreover, it is preferable to divide the inside of the tenter 64 into different temperature zones and adjust the drying conditions appropriately for each of the zones. In the tenter 64, the film 62 can be stretched in the width direction.

  After the film 62 is dried by the tenter 64, both end portions held by the tenter clip 64 a are cut and removed by the ear clip device 67. The separated both ends are sent to the crusher 103 by a cutter blower (not shown). By the crusher 103, the side end portion is crushed into chips. Since this chip is reused for dope manufacturing, the raw material can be effectively used.

  On the other hand, the film 62 from which both end portions have been cut and removed is then given a knurling while being nipped by the roller pair 65. The knurling imparted here can withstand the heating in the drying chamber 69 and is difficult to be deformed. Therefore, the knurling imparting step immediately before winding that is necessary in the cellulose acylate film production step is not required. When the knurling is applied, the film 62 has a solvent residual ratio in the range of 5% by mass to 30% by mass, more preferably in the range of 10% by mass to 30% by mass, and still more preferably in the range of 10% by mass to 25%. It is preferable to be dried in the range of mass% or less. If the solvent residual ratio at this time is larger than 30% by mass, the knurling position may be largely changed due to fluctuations in the drying conditions in the subsequent drying step. Since the knurling position of the final product is strictly determined, a product whose knurling position fluctuates cannot be a product. Therefore, the solvent residual ratio is preferably 30% by mass or less as described above. Moreover, if the solvent residual ratio of the film 62 when knurling is applied is smaller than 5% by mass, knurling may not be given to the film. In addition, said solvent residual rate is the value X of a dry weight reference | standard, and can be calculated | required by X (%) = {(mass of a film sample (g) -B) / B} * 100. The mass of the film sample is a value obtained by measuring a part of the film 62 immediately after being peeled off from the casting band 82 as a film sample, and B is 1 hour in an air thermostat at 115 ° C. It is the mass (g) measured after drying.

  The film 62 is sent to the drying chamber 69 and further dried. The internal temperature of the drying chamber 69 is not particularly limited, but is determined according to the thermal characteristics of the polymer, for example, the glass transition point Tg, the thermal deformation temperature, the melting point Tm, the continuous use temperature, etc. is there. In the drying chamber 69, the film 62 is conveyed while being wound around a roller 68, and the solvent gas generated by evaporation is adsorbed and recovered by the adsorption recovery device 106. The air from which the solvent component has been removed is sent again as drying air into the drying chamber 69. In addition, it is more preferable that the drying chamber 69 is divided into a plurality of sections in order to change the blowing temperature. When a preliminary drying chamber (not shown) is provided between the roller pair 65 and the drying chamber 69 and the film 62 is preliminarily dried at a temperature lower than the set temperature of the drying chamber 69, the film temperature rapidly increases in the drying chamber 69. Therefore, the shape change of the film 62 in the drying chamber 69 can be suppressed.

  The film 62 is cooled to approximately room temperature in the cooling chamber 71. In the case where a humidity control chamber is provided between the drying chamber 69 and the cooling chamber 71, it is preferable to blow air adjusted to a desired humidity and temperature onto the film 62 in the humidity control chamber. Thereby, it is possible to suppress the occurrence of curling of the film 62 and winding failure when winding.

  The film 62 is subjected to various processes such as a drying process and a side edge cutting and removing process from when the film 62 is peeled off from the casting band 82 to when the film 62 is wound. The film 62 is mainly supported or transported by a roller within each process or between the processes. These rollers include a driving roller and a non-driving roller, and the non-driving roller is mainly used for determining a film conveyance path and improving conveyance stability.

  It is preferable that the charge voltage of the film 62 is set to −3 kV to +3 kV by the static eliminating device 72.

  The film 62 is taken up by a take-up roll 107 in the take-up chamber 76. It is preferable to wind the film while applying a desired tension to the film 62 by the press roller. It is more preferable to gradually change the tension from the start to the end of winding, thereby preventing excessive winding in the film roll.

  The width of the film 62 wound up in this embodiment is 600 mm or more, for example, 1400 mm or more and 1800 mm or less.

  FIG. 3 is a schematic view of the roller pair 65 arranged in the conveyance path of the film 62. The roller pair 65 includes a first roller 121 disposed on the side of the film 62 peeled from the casting band (hereinafter simply referred to as a peeling surface) and the other surface of the film (hereinafter referred to as an anti-peeling surface). And a second roller 122 arranged on the side. The first roller 121 is a driving roller that is rotationally driven, and the second roller 122 is a roller that supports the film 62 and rotates by frictional force with the film 62. Thus, it is preferable that one of the first roller 121 and the second roller 122 be a driving roller and the other be a roller that is rotated by frictional force with the film 62.

  The first roller 121 rotates while extending in the width direction of the casting band, a shaft portion 124 that is not in contact with the film 62, and a contact member 125 that is attached to both ends of the shaft member 124 and is in contact with the film 62. Have The contact member 125 is movable in the longitudinal direction of the shaft member 124, and the position thereof can be changed according to a change in the width of the film 62 or a position where knurling is desired. The contact member 125 has a concavo-convex portion 125a having a concavo-convex formed on the peripheral surface. The shape of the second roller 122 is the same as that of the first roller 121. In FIG. 3, the shaft member is denoted by reference numeral 126, the contact member is denoted by reference numeral 127, and the concave and convex portions are denoted by reference numeral 127a. However, one of the first roller 121 and the second roller 122 may be made of an elastic material such as rubber.

  The first roller 121 and the second roller 122 sandwich the film 62, and the film 62 is conveyed downstream by the rotation of the first roller 121. The film 62 that has passed through the roller pair 65 has the same unevenness as the uneven shape of each of the uneven portions 125a and 127a of the first roller 121 and the second roller 122, and a knurling 131 made up of a large number of unevenness is given to both end portions. The As a result, the film 62 is dried while maintaining flatness on the roller 68 (see FIG. 2) of the drying chamber 69 (see FIG. 2) without generating slippage or wrinkles. Therefore, the obtained film as a product has uniform optical characteristics, and when this film is used in a liquid crystal display device, the image of the liquid crystal display device is very excellent. Further, according to this method, even a cyclic polyolefin having an elastic modulus lower than that of cellulose acylate can be stably and continuously produced.

  The knurling is preferably applied to both end portions of the film 62, but it is effective even if it is applied to only one side end portion. In the case where knurling is applied only to one side end, it is preferable to arrange a roller having a contact member attached to a shaft member shorter than the shaft members 124 and 126 on the peeling surface side and the anti-peeling surface side.

  FIG. 4 is a cross-sectional view of the film 62, and shows a case where knurling is applied to both surfaces of the film 62 by the first roller and the second roller having the same concavo-convex shape on the peripheral surface. Corresponding to the positions in contact with the convex portions on the peripheral surfaces of the first roller and the second roller, concave portions 151 and 152 are formed on the peeling surface 62a and the anti-peeling surface 62b, respectively.

  In the present invention, when the thickness T of the film 62 is not less than 30 μm and not more than 200 μm, the effect of preventing wrinkles and slipping is high. When the thickness T is less than 30 μm or larger than 200 μm, creases and wrinkles may be slightly confirmed depending on the type of cyclic polyolefin. The present invention is more effective when the thickness T is 30 μm or more and 150 μm or less, and is particularly effective when a film having a thickness of 40 μm or more and 110 μm or less is used for a liquid crystal display device.

The heights H1 and H2 of the knurling unevenness are preferably determined according to the thickness T of the film 62. In the case of the film 62 having an elastic modulus of 100 × 9.8 N / mm ² or more and 300 × 9.8 N / mm ² or less, the smaller the thickness T, the smaller the knurling heights H1 and H2, and the thickness T becomes smaller. The larger the knurling heights H1 and H2, the larger. Here, the heights H1 and H2 of the knurling are the depths of the concave portions 151 and 152 when the concave portions 151 and 152 are formed on the film 62, and the heights of the convex portions when the convex portions are formed. When a concave portion and a convex portion are formed, this is a value obtained by {(depth of concave portion) + (height of convex portion)}. The knurling heights H1 and H2 may be different from each other or may be the same value.

  By the way, the film 62 is different from the cellulose acylate film in the evaporation behavior of the solvent. Specifically, when the amount of solvent in the thickness direction is compared between the film 62 and the cellulose acylate film having the same solvent residual ratio, the film 62 has a solvent residual amount in the center in the thickness direction that is greater than that of the cellulose acylate film. The surface is less than the cellulose acylate film. Therefore, the recesses 151 and 152 in the film 62 preferably have a sharper cross-sectional shape than the knurling recess provided when the cellulose acylate film is produced by the solution casting method. The sharper cross-sectional shape means that the concave portion 151 is described. That is, the angle θ between the tangent to the peeling surface 62a of the elliptical arc in the cross section of the concave portion 151 and the peeling surface 62a is smaller.

  FIG. 4 shows a case where the recesses 151 and 152 of the peeling surface 62a and the anti-peeling surface 62b are elliptical arcs having the same size and shape, but the shapes and sizes of the two may be different from each other. As another aspect of the cross section, for example, when the knurling of the elliptic arc is provided on the peeling surface and the elliptical arc is provided on the anti-peeling surface, the elliptical arc is provided on the peeling surface, and the rectangular shape is provided on the anti-peeling surface. The case where the knurling of a recessed part is provided is mentioned.

  FIG. 5 is a cross-sectional view of a portion provided with a knurling, which is a film 172 according to another embodiment of the present invention. The concave portions 181 and 182 of the peeling surface 172a and the anti-peeling surface 172b are conical shapes having different sizes and shapes. And since the solvent residual rate is smaller on the side of the anti-peeling surface 172b of the film 171 than on the side of the peeling surface 172a, the concave portion 182 has a sharper shape than the concave portion 181, that is, the angle formed by the slope of the concave portion 182 and the anti-peeling surface 172b. θ is smaller than the angle formed by the inclined surface of the recess 181 and the peeling surface 172a, and H2> H1. In addition, it is preferable that the smaller the solvent residual ratio, the smaller the θ in the recesses 181 and 182 and the smaller the ratio of the flat portion. θ is preferably greater than 90 ° and 135 ° or less.

  In the present invention, when casting the dope 24, a method in which two or more kinds of dopes are simultaneously laminated co-cast or sequentially laminated co-cast may be used. When performing simultaneous lamination and co-casting, a casting die to which a feed block is attached may be used, or a multi-manifold casting die may be used. As for the film which consists of a multilayer by co-casting, it is preferable that any one of the two layers exposed on the surface has a thickness of 0.5% to 30% of the total thickness of the film. Furthermore, when performing simultaneous lamination and co-casting, a plurality of dopes having different viscosities are formed, and the dope with the higher viscosity is wrapped by the dope with the lower viscosity and flows out of the casting die. It is preferable to implement. Moreover, when performing simultaneous lamination | stacking co-casting, it is preferable that the dope which contact | connects the external world among casting beads, ie, exposes, has a ratio of a poor solvent larger than an internal dope.

  Of the following Experiments 1 to 11, Experiments 1 to 10 are embodiments of the present invention, and Experiment 11 is a comparative experiment for the present invention.

[Experiment 1]
(1) Synthesis of cyclic polyolefin 100 parts by mass of purified toluene and 100 parts by mass of norbornenecarboxylic acid methyl ester were placed in a reaction vessel. Next, 25 mmol% of ethylhexanoate-Ni dissolved in toluene, 0.225 mol% of tri (pentafluorophenyl) boron, and 0.25 mol% of triethylaluminum dissolved in toluene, Placed in reaction vessel. In addition, the density | concentration shown by these mmol% and mol% is a ratio with respect to the sum total of the number-of-moles of said toluene and norbornenecarboxylic acid methyl ester. And the polymerization reaction was implemented at room temperature for 18 hours, stirring the inside of a reaction tank. The liquid thus obtained was put in an excess amount of ethanol to precipitate the polymerization product. The precipitate was purified and vacuum dried at 65 ° C. for 24 hours to obtain a cyclic polyolefin.

(2) Preparation of dope raw material The dope 24 of cyclic polyolefin was made using the dope manufacturing equipment 10 shown in FIG. The raw materials and their blends are as shown below. In addition, as for the dichloromethane and methanol which are the raw materials of a solvent, water content is 0.5 mass% or less beforehand, respectively.
-Cyclic polyolefin 113 parts by mass-Dichloromethane 380 parts by mass-Methanol 70 parts by mass Dichloromethane and methanol were thoroughly stirred in a 4000 L stainless steel mixing tank 17 having a stirring blade. The mixing tank 17 is provided with a first stirrer 48 and a second stirrer 52. The first stirrer 48 includes an anchor blade on a rotating shaft portion, and the second stirrer 52 is a dissolver type eccentric stirrer. Next, the flaky powder of cyclic polyolefin was gradually added from the hopper 13 to the mixing tank 17. First, while rotating the rotation speed of the 1st stirrer 48 to the peripheral speed of 1 m / sec and the rotation speed of the 2nd stirrer 5 to 5 m / sec, it rotated for 30 minutes and disperse | distributed cyclic polyolefin in the solvent. The temperature at the start of dispersion was 25 ° C., and the temperature after 30 minutes was 48 ° C. Then, the amount of the additive solution prepared in advance was adjusted from the additive tank 15 with the valve 19 so that the total amount became 2000 kg. After completing the dispersion of the additive solution, high-speed stirring was stopped. Then, the rotation speed of the anchor blades of the first stirrer 48 was set at a peripheral speed of 0.5 m / second, and the mixture was further stirred for 100 minutes to obtain a mixed liquid 16 in which the cyclic polyolefin was swollen. Until the end of swelling, the inside of the mixing tank 17 was pressurized to 0.12 MPa with nitrogen gas. The inside of the mixing tank 17 at this time maintained an oxygen concentration of less than 2 vol% and no problem with explosion prevention. The water content in the mixed solution 16 was 0.3% by mass.

(3) Dissolution / filtration The mixed solution 16 was sent from the mixing tank 17 to the heating device 18 using the pump 41. The mixed solution 16 was heated to 50 ° C. with the heating device 18 and further heated to 90 ° C. under a pressure of 2 MPa to be completely dissolved. The heating time at this time was 15 minutes. The temperature of the dissolved mixed solution 16 was lowered to 36 ° C. with a temperature controller 21 and passed through a filtration device 22 having a filter medium having a nominal pore diameter of 8 μm to obtain a dope 24. The primary pressure in the filtration device 22 was 1.5 MPa, and the secondary pressure was 1.2 MPa. About the filtration apparatus 22, the filter, housing, and piping exposed to high temperature shall be made of Hastelloy (trade name) alloy and have excellent corrosion resistance, and provided with a jacket for circulating a heat transfer medium for heat insulation heating.

(4) Concentration / Filtration / Defoaming / Additive Next, the dope 24 was flash-evaporated in a flash device 26 at 80 ° C. and normal pressure, and the evaporated solvent was recovered by a condenser. The solid concentration of the dope 24 after flashing is 23% by mass. The condensed solvent was recovered by the recovery device 28 and regenerated by the regenerator 29 and sent to the solvent tank 11 to be reused for dope production. In the recovery device 28 and the regenerator 29, distillation and dehydration were performed. The tank which is the main body of the flash device 26 is provided with a stirrer (not shown) having an anchor blade on the stirrer shaft, and the stirrer is flashed to rotate the stirrer at a peripheral speed of 0.5 m / sec. And defoamed. The temperature of the dope 24 in this tank was 25 ° C., and the average residence time of the dope 24 in the tank was 50 minutes. The dope 24 was sampled and the shear viscosity measured at 25 ° C. was 450 Pa · s at a shear rate of 10 (sec ⁻¹ ).

  Next, bubbles were removed by irradiating the dope 24 with weak ultrasonic waves. Thereafter, the filtration device 27 was passed in a state where the dope 24 was pressurized to 1.5 MPa by the pump 42. The filter 27 is provided with two filters, a sintered fiber metal filter having a minimum nominal pore diameter of 10 μm on the upstream side and a sintered fiber filter having a minimum nominal pore diameter of 10 μm on the downstream side. Respective primary pressures were 1.5 MPa and 1.2 MPa, and secondary pressures were 1.0 MPa and 0.8 MPa. The temperature of the dope 24 after filtration was adjusted to 36 ° C., and the dope 24 was sent to a 2000 liter stainless steel stock tank 32 and stored. The stock tank 32 has a stirrer 78 having an anchor blade on the central axis, and the dope 24 was constantly stirred by rotating the anchor blade at a peripheral speed of 0.3 m / sec. Incidentally, no problems such as corrosion occurred at all in the wetted parts of the apparatus and members from the process of concentrating the dope 24 to the stock tank 32.

(5) Discharge / Just before addition / Casting / Bead decompression A film 62 was manufactured using the film manufacturing equipment 33. The dope 24 in the stock tank 32 was sent to the filtration device 61 by a high-precision gear pump 80. The gear pump 80 has a function of increasing the pressure on the primary side of the pump 80. Feedback control for the upstream side of the gear pump 80 was performed by an inverter motor so that the pressure on the primary side was 0.8 MPa. The gear pump 80 had a volume efficiency of 99.2%, a discharge rate variation rate of 0.5% or less, and a discharge pressure of 1.5 MPa. Then, the dope 24 that passed through the filtration device 61 was fed to the casting die 81.

  The casting die 81 had a width of 1.8 m, and the discharge amount of the dope 24 was adjusted so that the thickness T (unit: μm) after drying of the film 62 became the value shown in column 1 of Table 1. The width of the dope 24 discharged from the discharge port 81a, that is, the casting width was set to 1700 mm. The casting speed (unit: m / min) is shown in column 2 of Table 1. In order to adjust the temperature of the dope 24 to 20 ° C., a jacket (not shown) is provided on the casting die 81 and the inlet temperature of the heat transfer medium supplied into the jacket is set to 20 ° C.

  The casting die 81 and the piping were all kept at 20 ° C. during film formation. The casting die 81 was a coat hanger type die. The casting die 81 has an automatic thickness adjusting mechanism using a thickness adjusting bolt. A plurality of heat bolts that are thickness adjusting bolts are provided in the width direction of the casting die 81 at a pitch of 20 mm. The automatic thickness adjusting mechanism can set a thickness profile corresponding to the liquid feed amount of the gear pump 62. And this automatic thickness adjustment mechanism feedback-controls a heat volt | bolt based on the profile of the infrared thickness meter (not shown) installed in the film manufacturing equipment 33. FIG. Thus, the film 62 has a thickness difference of 1 μm or less at any two points separated by 50 mm in the width direction in the center portion excluding 20 mm for each side end portion, and the thickness variation in the width direction is 3 μm / m or less. The thickness was adjusted to be Moreover, the variation in the entire thickness was adjusted to be ± 1.5% or less with respect to the average thickness.

  In addition, a decompression chamber 90 for decompressing the upstream side of the casting beat 24 a is installed on the upstream side of the casting die 81. With this decompression chamber 90, the degree of decompression was adjusted according to the casting speed so that a constant pressure difference of 1 Pa to 5000 Pa was generated between the upstream side and the downstream side of the casting beat 24a. The constant value of the pressure difference was set so that the length of the casting beat 24a was 5 mm to 15 mm. In this embodiment, the pressure on the upstream side of the casting beat 24a is made 150 Pa lower than the front surface portion by the decompression chamber 90. A jacket (not shown) is attached to keep the internal temperature of the decompression chamber 90 at a predetermined temperature, and the heat transfer is adjusted to 35 ° C. so that the temperature is higher than the condensation temperature of the gas around the casting portion. Media was fed inside the jacket. Labyrinth packings (not shown) are provided on the upstream side and the downstream side of the casting beat 24a at the discharge port 81a. Further, openings were provided at both end portions of the discharge port 81a, and an edge suction device (not shown) for adjusting the disturbance of both edges of the casting beat 24a was attached. The edge suction device is capable of adjusting the edge suction air volume so as to be in the range of 1 L / min to 100 L / min. In this embodiment, the edge suction air volume is in the range of 30 L / min to 40 L / min. It adjusted suitably so that.

(6) Casting die The material of the casting die 81 is a precipitation hardening type stainless steel having a thermal expansion coefficient of 2 × 10 ⁻⁵ (° C. ⁻¹ ) or less. This is a material having corrosion resistance substantially equal to that of SUS316 in a forced corrosion test with an aqueous electrolyte solution. Further, this material had corrosion resistance that did not cause pitting (perforation) at the gas-liquid interface even when immersed in a mixed solution of dichloromethane, methanol, and water for 3 months. The finishing accuracy of the wetted surface of the casting die 81 was 1 μm or less in terms of surface roughness, the straightness was 1 μm / m or less in any direction, and the clearance of the slit was 1.0 mm. The corner portions of the liquid contact portions of the lip tips 81b and 81c of the casting die 81 are processed so that the chamfer radius R is 50 μm or less over the entire width. Further, a WC (tungsten carbide) coating was performed on the lip end of the casting die 81 by a thermal spraying method to provide a cured film.

  In order to prevent the dope 24 flowing out from the casting die 81 from being locally dried and solidified, a solvent for solubilizing the dope 24 is applied to the interface between the both end portions of the casting beat 24a and the discharge port 81a. On the other hand, 0.5 ml / min was supplied. The pulsation rate of the pump supplying the solvent was 5% or less. The solvent used was a mixture of 92 parts by mass of dichloromethane and 8 parts by mass of methanol.

(7) Casting Band A stainless steel endless band having a width of 2.1 m and a length of 70 m was used as the casting band 82. The casting band 82 is previously polished so that the thickness is 1.5 mm, the surface roughness is 0.05 μm or less, and the overall thickness unevenness is 0.5% or less. The material is SUS316, which has sufficient corrosion resistance and strength. The casting band 82 was run by two rotating rollers 85 and 86. The tension in the traveling direction of the casting band 82 during traveling is 1.5 × 10 ⁵ N / m ^{2 so} that the relative speed difference between the casting band 82 and the rotary rollers 85 and 86 is 0.01 m / min or less. In addition, the running speed fluctuation of the casting band 82 was set to 0.5% or less. Further, the positions of both end edges of the casting band 82 were detected and controlled so that the amount displaced in the width direction during one round of the casting band 82, that is, the meandering width was within 1.5 mm. Note that wind pressure fluctuation suppression means (not shown) is provided inside the casting chamber 63 to suppress fluctuations in pressure around the casting band 82.

  The rotary rollers 85 and 86 are capable of feeding a heat transfer medium inside so that the temperature of the casting band 82 can be adjusted. A heat transfer medium of 5 ° C. is passed through the rotation roller 85 on the casting die 81 side of the rotation rollers 85 and 86, and a heat transfer medium of 40 ° C. is applied to the other rotation roller 86 in order to dry the casting film 24 b. Shed. The surface temperature of the central part in the width direction of the casting band 82 immediately before casting was 15 ° C., and the temperature difference between both side ends was 6 ° C. or less.

  The vertical distance variation between the lip tip of the casting die 81 and the casting band 82 was set to be within 200 μm.

(8) Casting The temperature of the casting chamber 63 is maintained at 35 ° C. by the temperature control equipment 65. The discharge speed of the dope 27 from the casting die 43 was 2.5 m / min. The casting film 24b formed from the dope 24 cast on the casting band 82 was first fed with drying air flowing parallel to the casting film 24b to dry the casting film 24b. The overall heat transfer coefficient from the dry air to the casting film 24b was 24 kcal / (m ² · hr · ° C.). As for the temperature of the drying air, 135 ° C. drying air was blown from the upstream air duct 91 above the casting band 82. Further, a 140 ° C. dry air was blown from the downstream air duct 92, and a 65 ° C. dry air was blown from the air duct 93 below the casting band 82. The saturation temperature of each drying wind was around -8 ° C. The oxygen concentration in the dry atmosphere on the casting band 43 was maintained at 5 vol%. In order to maintain this oxygen concentration at 5 vol%, the air was replaced with nitrogen gas.

A wind shielding plate 73 was provided so that the dry air did not directly hit the casting beat 24a and the casting film 24b for 5 seconds after casting. Static pressure fluctuation in the vicinity of the casting die 81 was suppressed to ± 1 Pa or less. When the solvent content of the casting film 24b reached 15% by mass on the dry basis, the film was peeled off as the film 62 while being supported by the peeling roller 109 from the casting band 82. The stripping tension is 1 × 10 ² N / m ^2, and the stripping speed with respect to the speed of the casting band 82, that is, the stripping roller draw is in the range of 100.1% to 110% in order to suppress stripping failure. . The surface temperature of the film 62 when peeled off was 15 ° C. The drying rate of the film 62 on the casting band 82 was an average of 60% by mass / min on a dry basis.

  The solvent gas generated by the drying was condensed and liquefied by the condenser 98 set at −10 ° C. and recovered by the recovery device 99. Then, the solvent was treated so that the water content was 0.5% or less. The drying air from which the solvent was removed was heated again and reused as drying air. In the crossover part 101, 40 ° C. dry air was sent to the film 62 from the blower 102. Note that a tension of about 30 N was applied to the film 62 in the longitudinal direction during conveyance at the crossing portion 101.

(9) Tenter Stretching / Ear Cutting The film 62 sent to the tenter 64 was conveyed in the drying zone of the tenter 64 while being gripped at both ends by the clip 64a, and was dried by drying air during this time. The clip 64a was cooled by supplying a heat transfer medium at 20 ° C. The clip 64a was conveyed by a chain, and the speed fluctuation of the sprocket was 0.5% or less. Further, the inside of the tenter 64 was divided into three zones in the traveling direction of the film 62, and the temperature of the drying air in each zone was set to 90 ° C., 110 ° C., and 120 ° C. in order from the upstream side. The gas concentration of the drying air was a saturated gas concentration at -10 ° C. The conditions of each drying zone were adjusted so that the residual solvent amount of the film 62 was 7% by mass at the outlet of the tenter 64. The average drying speed inside the tenter 64 was 120% by mass / min on a dry basis. The stretch ratio from the peeling roller 109 to the entrance of the tenter 64, so-called tenter-driven draw, was 102%.

  In the tenter 64, when the width of the film 62 before stretching was 100%, the film 62 was stretched while being transported and dried so that the width after stretching was 103%. The stretching ratio at the tenter 64 is that the difference between the stretching ratios at any two points that are 10 mm or more away from each other in the width direction from the grip start position by the clip 64a is 10% or less, and any two points that are 20 mm apart. The difference in the stretching ratio was 5% or less. The ratio of the length from the grip start position to the grip release position with respect to the distance from the entrance to the exit of the tenter 64 was 90%. The solvent evaporated from the film 62 by the tenter 64 was condensed at −10 ° C., liquefied and recovered. A condenser was provided for condensation recovery, and the outlet temperature was -8 ° C. The condensed solvent was reused after adjusting the water content to 0.5% by mass or less. And it sent out from the tenter 64 as the film 62.

  The ears were cut at both ends of the film 62 by the ear-cleaver 50 within 30 seconds from the exit of the tenter 64. Ears 50 mm on both sides were cut with an NT-type cutter, and the cut ears were blown to a crusher 90 with a cutter blower (not shown) and crushed into chips of about 80 mm 2 on average. This chip was used again as a raw material for dope production together with CAB flakes as a raw material for dope preparation. The oxygen concentration in the dry atmosphere of the tenter 64 was kept at 5 vol%. Note that the air was replaced with nitrogen gas in order to maintain the oxygen concentration at 5 vol%. Prior to drying at a high temperature in a drying chamber 69 described later, the film 62 was preheated in a predrying chamber (not shown) to which 100 ° C. drying air was supplied.

(10) Application of knurling The tension (unit: N / m) applied in the longitudinal direction of the film 62 when applying knurling is shown in column 3 of Table 1. Since it has been confirmed in advance that this tension is the same as the tension in winding, Table 1 shows the set values of tension in the film longitudinal direction in winding. In column 4 of Table 1, KB is applied when knurling is applied to both the peeling surface 62a and the anti-peeling surface 62b, Ka is applied when only the peeling surface 62a is applied, and Kb is applied when only the anti-peeling surface is applied. The case where no is given is NB. The heights H1 and H2 (unit: μm) of the unevenness of the knurling are shown in column 5 of Table 1. “≦ 1” in Experiment 8 in column 5 indicates that knurling was applied, but the heights H1 and H2 of the unevenness were 1 μm or less, and specific numerical values could not be measured. The heights H1 and H2 of the knurling unevenness were controlled by adjusting the pressing force with the first and second rollers 121 and 122.

(11) Post-drying / static elimination The film 62 was dried in the drying chamber 69 at a high temperature. The drying chamber 69 is divided into four sections in the transport direction of the film 62, and 120 ° C., 130 ° C., 130 ° C., and 130 ° C. drying air is supplied from a blower (not shown) in order from the upstream section. did. The transport tension of the film 62 by the roller 68 was set to 100 N / m, and the film was dried for about 10 minutes until the residual solvent amount finally reached 0.3% by mass. The wrap angle of the film 62 on the roller 68, that is, the winding center angle of the film 62 was 90 degrees and 180 degrees. The material of the roller 68 was aluminum or carbon steel, and the surface thereof was subjected to hard chrome plating. The roller 68 has a smooth surface. The deflection of the position of the film 62 due to the rotation of the roller 68 was all 50 μm or less. As the roller 68, a roller 68 having a longitudinal deflection at a tension of 100 N / m of 0.5 mm or less was selected.

  The solvent gas contained in the drying air was adsorbed and recovered using the adsorption recovery device 106. The adsorbent used was activated carbon, and desorption was by dry nitrogen. The recovered solvent was reused as a dope preparation solvent after its water content was 0.3% by mass or less. Since the dry air contains solvent gas, plasticizer, UV absorber, and other high-boiling substances, these were removed with a cooler and a pre-adsorber, and the dry air was recycled and used. And adsorption / desorption conditions were set so that VOC (volatile organic compound) in outdoor exhaust gas was 10 ppm or less. Moreover, the solvent amount collect | recovered by a condensation method among all the evaporation solvents was 90 mass%, and most of the remainder was collect | recovered by adsorption collection.

  The dried film 62 was conveyed to a first humidity control chamber (not shown). A drying air of 110 ° C. was sent to the transition portion between the drying chamber 69 and the first humidity control chamber. Air having a temperature of 50 ° C. and a dew point of 20 ° C. was sent to the first humidity control chamber. Furthermore, the film 62 was transported to a second humidity control chamber (not shown) that suppresses the curling of the film 62, and air of 90 ° C. and 70% humidity was directly applied to the film 62.

(12) Winding condition After the humidity-controlled film 62 was cooled to 30 ° C. or lower in the cooling chamber 71, both end portions were cut and removed again by an edge-cutting device (not shown). The charged voltage of the film 62 conveyed by the static eliminating bar as the static eliminating device 72 was set to the range of -3 kV to +3 kV.

  Then, the film 62 was conveyed to the winding chamber 76. The winding chamber 76 was maintained at an internal temperature of 28 ° C. and a humidity of 70%. In the winding chamber 76, an ion wind static eliminating device (not shown) was installed so that the charged voltage of the film 62 was in the range of −1.5 kV to +1.5 kV. The diameter of the winding roll 107 is 169 mm. The variation width of the winding deviation at the time of winding, so-called oscillating width, was ± 5 mm, and the winding deviation period with respect to the winding roll 107 was 400 m. The pressing pressure of the press roller 108 against the winding roll 107 is 50 N / m. The temperature of the film 62 during winding was 25 ° C., the water content was 1.4% by mass, and the residual solvent amount was 0.3% by mass. Throughout the entire process, the average drying rate was 20% by mass / min on a dry basis. The total length of the wound film 62 is 3940 m, and the width is 1475 mm.

  Column 6 of Table 1 shows the results of evaluating the film. (1) is the result of visual evaluation of the presence or absence of scratches, ○ is “no scratches”, a × is “scratches on the release surface”, b × is “scratches on the anti-peeling surface”, and xx is “ "Scratch on both sides" means. (2) is the result of visual evaluation of the presence or absence of crevices and wrinkles, ◯ indicates “no creases and wrinkles”, and X indicates “existing creases and wrinkles”.

  Regarding [Experiment 2] to [Experiment 11], Table 1 shows conditions and evaluation results different from those in Experiment 1.

表１より、周面が平滑なローラでフィルムを支持しながら乾燥する工程の前にナーリングを付与することにより、ツレ、シワ等を防止することができることがわかる。そして、乾燥後のフィルムの厚み、流延速度、ナーリングを付与するときのフィルムの長手方向にかかる張力等の製膜条件を変化させても、同様の効果が得られることがわかる。

From Table 1, it can be seen that knurls, wrinkles, and the like can be prevented by applying knurling before the step of drying while supporting the film with a roller having a smooth peripheral surface. And even if it changes film forming conditions, such as the tension | tensile_strength concerning the thickness of the film after drying, a casting speed, and the film | membrane longitudinal direction when providing a knurling, it turns out that the same effect is acquired.

  According to the present invention, it can be seen that a cyclic polyolefin film can be easily and continuously produced without generating scratches, creases and wrinkles.

It is the schematic of the manufacturing apparatus of dope which is the embodiment of this invention. It is the schematic of the manufacturing equipment of the film which is the embodiment of the present invention. It is the schematic of a roller pair. It is sectional drawing of a film. It is sectional drawing of the film which is another embodiment of this invention.

Explanation of symbols

24 dope 62 film 65 roller pair 121,122 first roller, second roller

Claims (5)

A casting film forming step in which a dope containing a cyclic polyolefin and a solvent flows out of the casting die and forms a casting film on the traveling support;
A stripping step of stripping the cast film from the support as a wet film containing a solvent;
A stretching step of drying and stretching the wet film in the width direction while holding and transporting both side ends of the wet film by a holding means;
A knurling imparting step for imparting knurling to a side end of the wet film by bringing the wet film that has undergone the stretching process into contact with an uneven roller having irregularities on the peripheral surface;
A drying step of drying the wet film that has undergone the knurling step with a smoothing roller having a smooth peripheral surface to dry the wet film into a cyclic polyolefin film;
A winding step for winding the cyclic polyolefin film that has undergone the drying step;
The manufacturing method of the cyclic polyolefin film characterized by having. ^{2. The} method for producing a cyclic polyolefin film according to claim 1, wherein the cyclic polyolefin film has an elastic modulus of 100 × 9.8 N / mm ² or more and 300 × 9.8 N / mm ² or less.   The method for producing a cyclic polyolefin film according to claim 1 or 2, wherein the wet film has a solvent content of 5% by mass or more and 30% by mass or less when the knurling is applied.   The method for producing a cyclic polyolefin film according to any one of claims 1 to 3, wherein the knurling is applied to both surfaces of the wet film.   The method for producing a cyclic polyolefin film according to any one of claims 1 to 4, wherein the height of the unevenness of the knurling is determined according to a predetermined thickness of the cyclic polyolefin film.

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