JP2008274136A - Cycloolefin resin film, and polarizing plate, optical compensation film, antireflection film, and liquid crystal display using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cycloolefin resin film being reduced in the formation of cracks. <P>SOLUTION: The cycloolefin resin film has 1,000-30,000 J/m impact strength. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cycloolefin resin film, and a polarizing plate, an optical compensation film, an antireflection film, and a liquid crystal display device using the same.

 Conventionally, cycloolefin resin films produced by melt film formation are known (Patent Documents 1 to 3). However, the cycloolefin resin film obtained by these production methods, for example, when applied as a protective film for a polarizing plate, when the polarizing plate is punched, a crack is generated in the square part of the polarizing plate due to the impact vibration of the blade. Will occur. Further, such cracks are difficult to see with the naked eye, and when taken into a liquid crystal display device, fine cracks are visible in a crossed Nicol state, resulting in a liquid crystal display failure, and countermeasures have been desired.

JP 2005-114995 A JP 2006-290906 A JP 2004-67984 A

  An object of the present invention is to solve the above-described problems, and an object of the present invention is to provide a cycloolefin resin film with less cracking.

As a result of intensive studies by the inventors under the above problems, it has been found that the above problems can be solved by the following means.
(1) A cycloolefin resin film having an impact strength of 1000 J / m to 30000 J / m.
(2) The cycloolefin resin film according to (1), wherein the tear strength after being placed at 60 ° C. and 90% relative humidity for 500 hours is from 50 g / mm to 1000 g / mm.
(3) Thickness is 30 micrometers-250 micrometers, The cycloolefin resin film as described in (1) or (2) characterized by the above-mentioned.
(4) The method for producing a cycloolefin resin film according to any one of (1) to (3), which is produced by a melt film-forming method.
(5) The method for producing a cycloolefin resin film according to (4), wherein a shear rate between the gear pump and the die is set to 5 to 50 sec ⁻¹ .
(6) The ratio (X / Y) between the die tip clearance X and the maximum gap Y of the die cross-section flat part melt flow path is 0.01 to 0.5, (4) or (5) The manufacturing method of the cycloolefin resin film of description.
(7) The method for producing a cycloolefin resin film according to any one of (4) to (6), wherein the amount of neck-in of the melt discharged from the die is 90% to 99%.
(8) The production of the cycloolefin resin film according to any one of (4) to (7), wherein the film is formed by a touch roll method with a pressing pressure of a touch roll of 0.1 MPa to 10 MPa. Method.
(9) The method for producing a cycloolefin resin film according to any one of (4) to (7), wherein the film is formed by an electrostatic application method at an electrostatic voltage of 5 KV to 50 KV.
(10) The method for producing a cycloolefin resin film according to any one of (4) to (9), wherein the film forming speed on the uppermost cast roll is 20 m / min to 70 m / min.
(11) A cycloolefin resin film, wherein the film according to any one of (1) to (3) is stretched 1.01 to 3.0 times in at least one direction.
(12) The cycloolefin resin film according to any one of (1) to (3) and (11), wherein the cycloolefin is an addition-polymerized cycloolefin.
(13) A polarizing plate in which at least one layer of the cycloolefin resin film according to any one of (1) to (3), (11) and (12) is laminated.
(14) An optical compensation film using the cycloolefin resin film according to any one of (1) to (3), (11) and (12).
(15) An antireflection film using the cycloolefin resin film according to any one of (1) to (3), (11) and (12).
(16) The cycloolefin resin film according to any one of (1) to (3), (11) and (12), the polarizing plate according to (13), the optical compensation film according to (14), A liquid crystal display device using at least one of the antireflection films according to (15).

  According to the present invention, a cycloolefin resin film with few cracks was obtained.

  Hereinafter, the contents of the present invention will be described in detail. In the present specification, “to” is used to mean that the numerical values described before and after it are included as a lower limit value and an upper limit value. In the present specification, a “group” such as an alkyl group may or may not have a substituent unless otherwise specified. Further, in the case of a group having a limited number of carbons, the number of carbons means a number including the number of carbons that the substituent has.

The present invention relates to a cycloolefin resin film having an impact strength of 1000 J / m to 30000 J / m, and is likely to occur after a durability test by employing a cycloolefin resin film having improved impact strength in this way. Cracks can be suppressed. In particular, by employing the cycloolefin resin film of the present invention, it is possible to effectively suppress the failure occurrence rate on the display screen that occurs when incorporated in a liquid crystal display device.
Specifically, the inventor of the present application has found out that the cause of cracks is due to the brittleness of the cycloolefin resin film during the punching process. In particular, when impact vibration is applied to the film, it has been found that fine cracks (radial crack patterns) are generated at stress-concentrated portions, for example, at square portions. It has been found that such cracks become more apparent as the impact strength of the film is lower. Furthermore, it has been clarified that such film brittleness correlates with the degree of entanglement between molecules during film formation, and the present invention has been completed.

  The impact strength of the cycloolefin resin film of the present invention is preferably 2500 J / m to 25000 J / m, more preferably 3000 J / m to 23000 J / m, and particularly preferably 4000 J / m to 20000 J / m. When the impact strength is less than 1000 J / m, the total effect of entanglement between molecules is small, and the brittleness of the film is remarkable. On the other hand, when the impact strength exceeds 30000 J / m, the film has high viscosity, and plastic deformation is likely to occur during punching, which may cause dimensional changes. In particular, the impact strength of the stretched cycloolefin resin film is preferably 2000 J / m to 25000 J / m, and more preferably 3000 J / m to 20000 J / m.

  The cycloolefin resin film of the present invention preferably has a tear strength of 50 g / mm to 1000 g / mm, more preferably 100 g / mm to 900 g / mm, after 500 hours at 60 ° C. and 90% relative humidity. Preferably they are 150g / mm-800g / mm. By setting the tear strength to 50 g / mm or more, the entanglement interaction between molecules tends to increase, and cracks such as cracks are less likely to occur when the film is cut. On the other hand, by setting the tear strength to 1000 g / mm or less, the viscosity of the film does not become too strong, and when punching is performed, cutting tends to occur and cutting defects tend not to occur.

  It is preferable that the thickness of the cycloolefin resin film of this invention is 30-250 micrometers, More preferably, it is 40-200 micrometers, More preferably, it is 40-100 micrometers. By setting the thickness to 30 μm or more, breaks or the like are hardly generated, and the handling property tends to be improved. When the thickness is 250 μm or less, a large cutting stress is less likely to be generated during punching, and cracks tend to be less likely to occur.

On the other hand, the cycloolefin resin film of the present invention can be produced by melt film formation. Furthermore, the reduction of cracks and / or improvement of impact strength can be achieved by using the following film forming technique.
Shear rate between the dies from the gear pump is preferably 5～50Sec ^-1, more preferably 8～45Sec ^-1, more preferably from 10~40sec ^-1. Here, the shear rate between the gear pump and the die can be obtained by the following equation from the resin volume flow rate ratio Q (mm ³ / sec ⁻¹ ) and the pipe diameter D (mm) in the pipe.
Shear rate (sec ^-1 ) = 32Q / (π · D ³ )
Thereby, the entanglement degree between molecules at the time of film formation improves, and it can aim at reduction of the crack generation rate of a film obtained as a result, and improvement of impact strength. By setting the melt shear rate in the pipe to 5 sec ⁻¹ or more, the shear force of the melt becomes strong, mixing at the molecular level is sufficient, and the degree of entanglement tends to be improved. On the other hand, by setting the melt shear rate to 50 sec ⁻¹ or less, molecular breakage and crosslinking are unlikely to occur, and the membrane brittleness tends to be less likely to decrease. Such a shear rate can also be controlled using a stouch mixer in the pipe.

Further, the ratio (X / Y) between the die tip clearance X and the die section flat portion maximum melt flow path gap Y is preferably 0.01 to 0.5, more preferably 0.02 to 0.3. Yes, more preferably 0.05 to 0.2. FIG. 1 shows the die tip clearance X and the die section flat portion maximum melt flow path gap Y.
Thereby, the entanglement between melt molecules can be increased in the die discharge part, and a synergistic effect of reducing the crack generation rate and improving the impact strength can be obtained. Further, by setting the ratio (X / Y) to 0.01 or more, the entanglement between the melt molecules tends to increase, and the film brittleness improving effect tends to be easily obtained.

The neck-in amount of the melt discharged from the die is preferably 90% to 99%, more preferably 92% to 98%, and still more preferably 93% to 97%. By setting the neck-in to 90% or more, it is difficult for residual stress to remain in the melt film discharged due to contraction force, and the impact strength tends to be improved. On the other hand, if it is 99% or less, the molecular entanglement in the discharged melt is hardly relaxed and the impact strength tends to be improved. The amount of neck-in here is calculated by the following formula from the width of the melt resin discharged from the die (die discharge melt resin width (a)) and the width of the melt resin on the cast roll (melt resin width (b)). can do. FIG. 2 schematically shows the relationship between the die discharge melt resin width (a) and the melt resin width (b).
Neck-in amount = b / a * 100%
In particular, the cycloolefin resin film of the present invention is preferably formed by a touch roll method with a press roll pressing pressure of 0.1 MPa to 10 MPa. Here, the press pressure of the touch roll refers to a pressure that the touch roll presses into the melt resin. Furthermore, the press pressure of the touch roll is more preferably 1 to 8 MPa. In the present invention, an ultra-low pressure prescale (manufactured by Fuji Film Co., Ltd.) is sandwiched between the touch roll and the cast roll, and the contact pressure is measured using a densitometer FPD-305E (manufactured by Fuji Film Co., Ltd.). The average value is obtained from the surface pressure of the entire width and is used as the press pressure of the touch roll.
The cycloolefin resin film of the present invention is preferably formed by an electrostatic application method at an electrostatic voltage of 5 KV to 50 KV. The electrostatic application method is described in JP-A-10-193438, JP-A-11-20003, JP-A-2004-299099, and the like. Furthermore, the static voltage by the electrostatic application method is more preferably 6 KV to 40 KV.
By adopting such means, the neck-in amount can be adjusted to the above range.

 The film forming speed (line speed) on the most upstream cast roll is preferably 20 m / min to 70 m / min, more preferably 25 m / min to 60 m / min, and further preferably 30 m / min to 50 m / min. Minutes. By setting such a line speed, a stretching effect can be given to the inside of the film with a touch roll and a cast roll. By making such a high speed, the time for the touch roll to come into contact with the film can be shortened, thereby giving an abrupt molecular level stretching effect, thereby obtaining an effect of improving the brittleness of the film. In particular, by setting it to 20 m / min or more, the stretching effect between molecules becomes sufficient, and by setting it to 70 m / min or less, thickness unevenness due to uneven rotation of the touch roll and cast roll is less likely to occur.

Hereinafter, the present invention will be described in more detail.
《Cycloolefin resin》
First, the cycloolefin resin used for the cycloolefin resin film of this invention is demonstrated.
The cycloolefin resin in the present invention is not particularly defined as long as it does not depart from the gist of the present invention. For example, those described below can be adopted.

(Cycloolefin resin-A / ring-opening polymerization type)
As the cycloolefin resin-A used in the present invention, for example, (1) a ring-opening (co) polymer of a norbornene monomer is subjected to polymer modification such as maleic acid addition or cyclopentadiene addition as necessary. , Hydrogenated resins, (2) resins obtained by addition polymerization of norbornene monomers, and (3) resins obtained by addition copolymerization with norbornene monomers and olefin monomers such as ethylene and α-olefin. it can. The polymerization method and the hydrogenation method can be performed by conventional methods.

  Examples of the norbornene-based monomer include norbornene and alkyl and / or alkylidene substituted products thereof such as 5-methyl-2-norbornene, 5-dimethyl-2-norbornene, 5-ethyl-2-norbornene, and 5-butyl. 2-norbornene, 5-ethylidene-2-norbornene and the like, and polar group substitution products thereof such as halogen; dicyclopentadiene, 2,3-dihydrodicyclopentadiene, etc .; dimethanooctahydronaphthalene, its alkyl and / or Or an alkylidene-substituted product and a polar group-substituted product such as halogen, for example, 6-methyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-ethyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8, a-octahydronaphthalene, 6-ethylidene-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-chloro-1,4: 5 8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-cyano-1,4: 5,8-dimethano-1,4,4a, 5,6,7, 8,8a-octahydronaphthalene, 6-pyridyl-1,4: 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 6-methoxycarbonyl-1,4 : 5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, etc .; adducts of cyclopentadiene and tetrahydroindene, etc .; 3-tetramers of cyclopentadiene, for example, 4,9: 5,8-dimethano-3a, , 4a, 5,8,8a, 9,9a-octahydro-1H-benzoindene, 4,11: 5,10: 6,9-trimethano-3a, 4,4a, 5,5a, 6,9,9a, 10, 10a, 11, 11a-dodecahydro-1H-cyclopentanthracene; and the like.

(Cycloolefin resin-B / ring-opening polymerization type)
Moreover, as cycloolefin resin, the cycloolefin resin represented by following General formula (1)-(4) can be mentioned, Among these, what is represented by the following general formula (1) is especially preferable.

〔一般式（１）〜（４）中、Ａ、Ｂ、ＣおよびＤは、それぞれ、水素原子または１価の有機基を示し、これらのうち少なくとも１つは極性基である。〕

[In General Formulas (1) to (4), A, B, C and D each represent a hydrogen atom or a monovalent organic group, and at least one of them is a polar group. ]

Here, the monovalent organic group, or a hydrocarbon group having 1 to 20 carbon atoms - (CH ₂₎ such as _n COOR and the like. (Here, R represents a hydrocarbon group having 1 to 20 carbon atoms, and n represents an integer of 0 to 10).

  As the cycloolefin resin in the present invention, at least one tetracyclododecene derivative represented by the following general formula (5) can be used alone or as a copolymer with the tetracyclododecene derivative. A hydrogenated polymer obtained by hydrogenating a polymer obtained by metathesis polymerization with an unsaturated cyclic compound may be used.

（一般式（５）中、Ａ、Ｂ、ＣおよびＤは、それぞれ、水素原子または１価の有機基を示し、これらのうち少なくとも１つは極性基である。）

(In general formula (5), A, B, C and D each represent a hydrogen atom or a monovalent organic group, and at least one of them is a polar group.)

In the tetracyclododecene derivative represented by the general formula (5), examples of the organic group include the organic groups described in the general formulas (1) to (4). Furthermore, when at least one of A, B, C and D is a polar group, a polarizing film excellent in adhesion to other materials, heat resistance and the like can be obtained. Furthermore, the polar group is a group represented by — (CH ₂ ) _n COOR (where R is a hydrocarbon group having 1 to 20 carbon atoms, and n is an integer of 0 to 10). Since the finally obtained hydrogenated polymer (cycloolefin resin film) has a high glass transition temperature, it is preferable. In particular, the polar substituent represented by — (CH ₂ ) _n COOR is preferably contained in one molecule of the tetracyclododecene derivative of the general formula (5) from the viewpoint of reducing the water absorption rate. In the polar substituent, it is preferable in that the hygroscopicity of the obtained hydrogenated polymer decreases as the number of carbon atoms of the hydrocarbon group represented by R increases, but the balance with the glass transition temperature of the obtained hydrogenated polymer. From the above point, the hydrocarbon group is preferably a chain alkyl group having 1 to 4 carbon atoms or a (poly) cyclic alkyl group having 5 or more carbon atoms, particularly a methyl group, an ethyl group, or a cyclohexyl group. Preferably there is.

Further, the tetracyclododecene derivative of the general formula (5) in which a hydrocarbon group having 1 to 10 carbon atoms is bonded as a substituent to a carbon atom to which a group represented by — (CH ₂ ) _n COOR is bonded is Since the resulting hydrogenated polymer has low hygroscopicity, it is preferable. In particular, the tetracyclododecene derivative of the general formula (5) in which the substituent is a methyl group or an ethyl group is preferable in terms of easy synthesis. Specifically, 8-methyl-8-methoxycarbonyltetracyclo [4,4,0,12.5,17.10] dodec-3-ene is preferable. These tetracyclododecene derivatives and mixtures of unsaturated cyclic compounds copolymerizable therewith are disclosed, for example, in JP-A-4-77520, page 4, upper right column, line 12 to page 6, lower right column, line 6. Metathesis polymerization and hydrogenation can be carried out by the methods described.

As the cycloolefin resin in the present invention, a cycloolefin resin (addition polymerization type) having the following structure can be used.
[A-1]: hydrogenated product of random copolymer of α-olefin having 2 to 20 carbon atoms and cyclic olefin represented by general formula (6),
[A-2]: hydrogenated product of ring-opening polymer or copolymer of cyclic olefin represented by the following general formula (6)

一般式（６）中、ｎは０または１であり、ｍは０または１以上の整数であり、ｑは０または１である。
なお、ｑが１の場合には、Ｒ^aおよびＲ^bは、それぞれ、下記に示す原子または炭化水素基であり、ｑが０の場合には、それぞれの結合手が結合して５員環を形成する。 General formula (6)

In general formula (6), n is 0 or 1, m is 0 or an integer of 1 or more, and q is 0 or 1.
When q is 1, each of R ^a and R ^b is an atom or a hydrocarbon group shown below. When q is 0, each bond is bonded to form a 5-membered ring. Form.

で示されるビシクロ［２．２．１］−２−ヘプテン（＝ノルボルネン）（上記式において、１〜７の数字は炭素の位置番号を示す。）および該化合物に炭化水素基が置換した誘導体が挙げられる。 R ^{1 to} R ¹⁸ and R ^a and R ^b are each a hydrogen atom, a halogen atom or a hydrocarbon group. Here, examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the hydrocarbon group include an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 15 carbon atoms, and an aromatic hydrocarbon group. More specifically, examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an amyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, and an octadecyl group, and the cycloalkyl group includes a cyclohexyl group. Group, and examples of the aromatic hydrocarbon group include a phenyl group and a naphthyl group. These hydrocarbon groups may be substituted with a halogen atom. Furthermore, in the above general formula (6), R ^{15 to} R ¹⁸ may be bonded to each other (in cooperation with each other) to form a monocyclic or polycyclic ring, and the monocyclic or polycyclic ring thus formed The polycycle may have a double bond.
Specific examples of the cyclic olefin represented by the general formula (6) are shown below. As an example,

And bicyclo [2.2.1] -2-heptene (= norbornene) represented by the formula (wherein the numbers 1 to 7 represent carbon position numbers) and a derivative in which a hydrocarbon group is substituted on the compound. Can be mentioned.

 As this substituted hydrocarbon group, 5-methyl group, 5,6-dimethyl group, 1-methyl group, 5-ethyl group, 5-n-butyl group, 5-isobutyl group, 7-methyl group, 5-phenyl group , 5-methyl-5-phenyl group, 5-benzyl group, 5-tolyl group, 5- (ethylphenyl) group, 5- (isopropylphenyl) group, 5- (biphenyl) group, 5- (β-naphthyl) Examples thereof include a group, a 5- (α-naphthyl) group, a 5- (anthracenyl) group, and a 5,6-diphenyl group.

 Still other derivatives include cyclopentadiene-acenaphthylene adduct, 1,4-methano-1,4,4a, 9a-tetrahydrofluorene, 1,4-methano-1,4,4a, 5,10,10a-hexahydro. Bicyclo [2.2.1] -2-heptene derivatives such as anthracene can be exemplified.

で示されるテトラシクロ［４．４．０．１^2,5．１^7,10］−３−ドデセン、およびこれに炭化水素基が置換した誘導体が挙げられる。 In addition, tricyclo [4.3.0.1 ^2,5 ] -3-decene, 2-methyltricyclo [4.3.0.1 ^2,5 ] -3-decene, 5-methyltricyclo [4 .3.0.1 ^2,5 ] -3-decene and other tricyclo [4.3.0.1 ^2,5 ] -3-decene derivatives, tricyclo [4.4.0.1 ^2,5 ] -3 A tricyclo [4.4.0.1 ^2,5 ] -3-undecene derivative such as undecene, 10-methyltricyclo [4.4.0.1 ^2,5 ] -3-undecene,

Tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, and derivatives substituted with a hydrocarbon group.

 As the hydrocarbon group, 8-methyl group, 8-ethyl group, 8-propyl group, 8-butyl group, 8-isobutyl group, 8-hexyl group, 8-cyclohexyl group, 8-stearyl group, 5,10- Dimethyl group, 2,10-dimethyl group, 8,9-dimethyl group, 8-ethyl-9-methyl group, 11,12-dimethyl group, 2,7,9-trimethyl group, 2,7-dimethyl-9- Ethyl group, 9-isobutyl-2,7-dimethyl group, 9,11,12-trimethyl group, 9-ethyl-11,12-dimethyl group, 9-isobutyl-11,12-dimethyl group, 5,8,9 , 10-tetramethyl group, 8-ethylidene group, 8-ethylidene-9-methyl group, 8-ethylidene-9-ethyl group, 8-ethylidene-9-isopropyl group, 8-ethylidene-9-butyl group, 8- n-propylidene 8-n-propylidene-9-methyl group, 8-n-propylidene-9-ethyl group, 8-n-propylidene-9-isopropyl group, 8-n-propylidene-9-butyl group, 8-isopropylidene group 8-isopropylidene-9-methyl group, 8-isopropylidene-9-ethyl group, 8-isopropylidene-9-isopropyl group, 8-isopropylidene-9-butyl group, 8-chloro group, 8-bromo group , 8-fluoro group, 8,9-dichloro, 8-phenyl group, 8-methyl-8-phenyl group, 8-benzyl group, 8-tolyl group, 8- (ethylphenyl) group, 8- (isopropylphenyl) Group, 8,9-diphenyl group, 8- (biphenyl) group, 8- (β-naphthyl) group, 8- (α-naphthyl) group, 8- (anthracenyl) group, 5,6-diphenyl group, etc. Rukoto can.

Furthermore, tetracyclo [4.4.0.1 ^2,5 ... Adducts of (cyclopentadiene-acenaphthylene adduct) and cyclopentadiene. 1 ^7,10 ] -3-dodecene derivative, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13] -4-pentadecene and its derivatives, pentacyclo [7.4.0.1 ^2,5. 1 ^9,12 . 0 ^8,13] -3-pentadecene and its derivatives, pentacyclo [8.4.0.1 ^2,5. 1 ^9,12 . 0 ^8,13] -3-hexadecene and derivatives thereof, pentacyclo [6.6.1.1 ^{3, 6.} 0 ^2,7 . 0 ^9,14] -4-hexadecene and derivatives thereof, hexacyclo [6.6.1.1 ^{3, 6.} 1 ^10,13 . 0 ^2,7 . 0 ^9,14] -4-heptadecene and its derivatives, heptacyclo [8.7.0.1 ^2,9. 1 ^4,7 . 1 ^11,17 . 0 ^3,8 . 0 ^12,16 ] -5-eicosene and its derivatives, heptacyclo [8.7.0.1 ^3,6 . 1 ^10,17 . 1 ^12,15 . 0 ^2,7 . 0 ^11,16 ] -4-eicosene and its derivatives, heptacyclo [8.8.0.1 ^2,9 . 1 ^4,7 . 1 ^11,18 . 0 ^3,8 . 0 ^12,17 ] -5- ^heneicosene and its derivatives, octacyclo [8.8.0.1 ^2,9 . 1 ^4,7 . 1 ^11,18 . 1 ^13,16 . 0 ^3,8 . 0 ^12,17 ] -5-docosene and derivatives thereof, nonacyclo [10.9.1.1 ^4,7 . 1 ^13,20 . 1 ^15,18 . 0 ^2,10 . 0 ^3,8 . 0 ^12,21 . 0 ^14,19] -5-pentacosene and derivatives thereof.

Specific examples of these cycloolefin resins are as described above, but more specific structures of these compounds are shown in paragraphs [0032] to [0054] of JP-A-7-145213. Yes.
Moreover, about the synthesis method of these cycloolefin resin, it can carry out with reference to paragraph number [0039]-[0068] of Unexamined-Japanese-Patent No. 2001-114836.

The following can also be used as the cycloolefin resin (addition polymerization type) of the present invention.
A cycloolefin (co) polymer having a polymer unit derived from a compound represented by the following formula (I), (II), (II ′), (III), (IV), (V) or (VI) is also preferred.

式中、Ｒ⁹、Ｒ¹⁰、Ｒ¹¹およびＲ¹²は、それぞれ、水素原子、または、炭素数１〜８のアルキル基、炭素数６〜１８のアリール基等の直鎖または分岐の、飽和または不飽和の、炭素数１〜２０の炭化水素基である。 In the above formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each a hydrogen atom, a linear or branched alkyl group having 1 to 8 carbon atoms, and the number of carbon atoms C6-C20 hydrocarbon group such as 6-18 aryl group, C7-20 alkylene aryl group, C2-C20 alkenyl group which may be cyclic, saturated, unsaturated or aromatic To form a cyclic group. n is an integer of 0-5.

In the formula, each of R ⁹ , R ¹⁰ , R ^11, and R ¹² is a hydrogen atom, or a linear or branched, saturated or saturated group such as an alkyl group having 1 to 8 carbon atoms or an aryl group having 6 to 18 carbon atoms. An unsaturated hydrocarbon group having 1 to 20 carbon atoms.

  The cycloolefin (co) polymer is obtained, for example, by ring-opening polymerization of at least one of the compounds represented by the formulas (I) to (VI), and then hydrogenating the obtained product. be able to.

式中、ｎは２〜１０の数である。 Moreover, the cycloolefin (co) polymer which contains the polymer unit derived from the compound represented by a following formula (VIII) in the said polymer 0-45 mol% of the whole is also preferable.

In the formula, n is a number of 2 to 10.

  The proportion of polymerized units derived from cyclic, especially polycyclic olefins, is preferably 3 to 75 mol% of the cycloolefin (co) polymer. The proportion of the polymer units derived from the acyclic olefin is preferably 5 to 80 mol% of the cycloolefin (co) polymer.

  The cycloolefin (co) polymer is preferably one or more polycyclic olefins, in particular polymerized units derived from a compound of formula (I) or a compound of formula (III), and It consists of polymerized units derived from compounds of the formula (VII), in particular α-olefins having 2 to 20 carbon atoms. Preferably, a cyclohexane comprising a polymer unit derived from a compound represented by formula (I) or a compound represented by formula (III) and a polymer unit derived from a compound represented by formula (VII) is preferred. Olefin copolymer. More preferably, it contains a polymer unit derived from a compound represented by formula (I) or formula (III), a polymer unit derived from a compound represented by formula (VII), and at least two double bonds Cyclic or acyclic olefins (polyenes), for example, especially cyclic, preferably polycyclic dienes such as norbornadiene, particularly preferably, for example, vinyl norbornene carrying an alkenyl group having 2 to 20 carbon atoms It is a three-dimensional polymer composed of polymer units derived from polycyclic alkenes.

  The cycloolefin resin used in the present invention preferably contains an olefin based on a norbornene structure, particularly preferably norbornene, tetracyclododecene, and optionally vinyl norbornene or norbornadiene. Also preferred are cycloolefins (copolymers) comprising polymerized units derived from α-olefins having for example 2 to 20 carbon atoms, particularly preferably acyclic olefins having terminal double bonds such as ethylene or propylene. ) Polymer. Particularly preferred are norbornene / ethylene copolymers and tetracyclododecene / ethylene copolymers.

  Among the three-dimensional polymers, three-dimensional polymers of norbornene / vinyl norbornene / ethylene, norbornene / norbornadiene / ethylene terpolymer, tetracyclododecene / vinylnorbornene / ethylene terpolymer, and tetracyclododecene / vinyl are particularly preferable. Tetracyclododecene-ethylene three-dimensional polymer. The proportion of polymerized units derived from polyenes, preferably vinyl norbornene or norbornadiene, is 0.1 to 50 mol%, particularly preferably 0.1 to 20 mol%, based on the total structure of the cycloolefin resin, The proportion of the acyclic monoolefin represented by (VII) is usually 0 to 99 mol%, preferably 5 to 80 mol%. In the said three-dimensional polymer, Preferably it is 0.1-99 mol% of a cycloolefin (co) polymer, More preferably, it is 3-75 mol%.

The cycloolefin resin used in the present invention preferably contains at least a polymer unit that can be derived from the compound represented by formula (I) and a polymer unit that can be derived from the compound represented by formula (VII). Contains one type of cycloolefin (co) polymer.
Such cycloolefin (co) polymer can be synthesized according to paragraph numbers 0019 to 0020 of JP-A-10-168201.

As the cycloolefin resin in the present invention, JP-A-60-168708, JP-A-62-252406, JP-A-62-2252407, JP-A-2-133413, JP-A-63. Resins described in JP-A-145324, JP-A-63-264626, JP-A-1-240517, and JP-B-57-8815 can be employed.
In the present invention, those obtained by addition polymerization of norbornene monomers are particularly preferred.

 The cycloolefin resin in the present invention preferably has a glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of 70 ° C or higher, more preferably 90 ° C to 185 ° C, and still more preferably It is 100-165 degreeC, and 120-160 degreeC is especially preferable.

As a weight average molecular weight of the cycloolefin resin in this invention, 5,000-1,000,000 are preferable, More preferably, it is 8,000-200,000.
The cycloolefin resin in the present invention preferably has a saturated water absorption of 1% by mass or less, more preferably 0.8% by mass or less. For example, the glass transition temperature (Tg) and saturated water absorption of the cycloolefin resins represented by the general formulas (1) to (4) are controlled by selecting the type of the substituents A, B, C, and D. be able to.

  The cycloolefin resin in the present invention preferably has an intrinsic viscosity (ηinh) measured at 30 ° C. in chloroform of 0.1 to 1.5 dl / g, more preferably 0.4 to 1.2 dl / g. g. Moreover, it is preferable that intrinsic viscosity [(eta)] measured in 135 degreeC decalin is 0.01-20 dl / g normally, More preferably, it is 0.03-10 dl / g, More preferably, 0.05- The melt flow index (MFR) measured at 260 ° C. under a load of 2.16 kg according to ASTM D1238 is preferably 0.1 to 200 g / 10 min, more preferably 1 to 100 g / 10 min. More preferably, it is 5 to 50 g / 10 minutes.

 Furthermore, the softening point of the cycloolefin resin in the present invention is preferably 30 ° C. or higher, preferably 70 ° C. or higher, more preferably 80 to 260 ° C. as the softening point measured with a thermal mechanical analyzer (TMA). .

In the cycloolefin resin of the present invention, the hydrogenation rate of the hydrogenated polymer is preferably 50% or more, more preferably 90% or more, and further preferably 60 MHz or more as measured by ¹ H-NMR. Is 98% or more. The higher the hydrogenation rate, the more the resulting cycloolefin resin film is more stable against heat and light. Moreover, it is preferable that gel content contained in this hydrogenated polymer is 5 mass% or less, More preferably, it is 1 mass% or less.

 The cycloolefin resin in the present invention is preferably amorphous or low crystalline, and the crystallinity measured by X-ray diffraction method is preferably 20% or less, more preferably 10% or less, More preferably, it is 2% or less.

(Stabilizer)
In the present invention, it is preferable that at least one stabilizer is added to the film constituting material before or when the cycloolefin resin is heated and melted. These include coloration and molecular weight reduction, including decomposition reactions that have not been elucidated, such as preventing oxidation of film components, capturing acid generated by decomposition, and inhibiting or prohibiting decomposition reactions caused by radical species due to light or heat. This is useful for suppressing the generation of volatile components due to alterations such as At that time, the stabilizer itself is required to function without being decomposed even at a melting temperature for film formation. These stabilizers are used for the following effects, but are not limited thereto.
Typical stabilizers include phenolic stabilizers, phosphite stabilizers (phosphite), thioether stabilizers, amine stabilizers, epoxy stabilizers, lactone stabilizers, amine stabilizers. Agents, metal deactivators (tin-based stabilizers), and the like. These are described in JP-A-3-199201, JP-A-5-1907073, JP-A-5-194789, JP-A-5-271471, JP-A-6-107854, and the like. Then, it is preferable to use at least one of a phenol-based or phosphorous acid-based stabilizer.
The stabilizers can be used alone or in combination of two or more, and the blending amount thereof is appropriately selected within a range not impairing the object of the present invention. The addition amount of the stabilizer is preferably 0.001 to 5 parts by mass, more preferably 0.005 to 3 parts by mass, and further 0.01 to 0.8 parts by mass with respect to 100 parts by mass of the cycloolefin resin. preferable.

(Phenolic stabilizer)
In the present invention, a compound used for stabilizing the film constituting material at the time of heat melting, and a known phenol-based stabilizer can be used. For example, U.S. Pat. 2,6-dialkylphenol derivative compounds such as those described in the column are included.
Among these, it is particularly preferable to add a phenol-based stabilizer having a molecular weight of 500 or more. Preferable phenolic stabilizers include hindered phenolic stabilizers. In particular, it is preferable to have a substituent at a site adjacent to the hydroxyphenyl group. In this case, the substituted group is preferably a substituted or unsubstituted alkyl group having 1 to 22 carbon atoms. The phenolic stabilizer that can be used in the present invention is not limited to these.
These materials are readily available as commercial products. For example, Irganox 1076, Irganox 1010, Irganox 3113, Irganox 245, Irganox 1135, Irganox 1330, Irganox 25, sold by Ciba Specialty Chemicals. Irganox 565, Irganox 1035, Irganox 1098, Irganox 1425WL. Moreover, ADK STAB AO-50, ADK STAB AO-60, ADK STAB AO-20, ADK STAB AO-70, and ADK STAB AO-80 sold by Asahi Denka Kogyo Co., Ltd. are listed. Furthermore, Sumilizer BP-76, Sumilizer BP-101, and Sumilizer GA-80 sold by Sumitomo Chemical Co., Ltd. may be mentioned. Moreover, Cynox 326M and Cynox 336B currently sold from Sipro Kasei Co., Ltd. are mentioned.

(Phosphorous acid stabilizer)
As phosphorous acid stabilizers, [0023] to [0039] of JP-A No. 2004-182979, JP-A No. 51-70316, JP-A No. 10-306175, JP-A No. 57-78431 are disclosed. , JP-A-54-157159, JP-A-55-13765, and the Technical Report of the Japan Society of Invention (Public Technical Number 2001-1745, published on March 15, 2001, Japan Society of Invention and Innovation), pages 17-22. Mention may be made of the compounds described. Of course, the phosphite stabilizers that can be used in the present invention are not limited to these.
The phosphite stabilizer of the present invention is useful to have a high molecular weight in order to maintain stability at high temperature, preferably has a molecular weight of 500 or more, more preferably has a molecular weight of 550 or more, and further preferably Has a molecular weight of 600 or more. Furthermore, it is preferred that at least one substituent is an aromatic ester group. The phosphite ester stabilizer is preferably a triester, and is desirably free of impurities such as phosphoric acid, monoester and diester. When these impurities are present, the content is preferably 5% by mass or less, more preferably 3% by mass or less, and particularly preferably 2% by mass or less.
These are ADK STAB 1178, 2112, PEP-8, PEP-24G, PEP-36G and HP-10 sold by Asahi Denka Kogyo Co., Ltd., and Sandostab P sold by Clariant. -Available as EPQ. Furthermore, a stabilizer having phenol and phosphite in the same molecule is also preferably used. As these compounds, for example, compounds described in detail in JP-A No. 10-273494 can be adopted, but are not limited thereto. As a typical commercially available product, there can be mentioned a Sumizer GP sold by Sumitomo Chemical Co., Ltd.

(Thioether stabilizer)
The thioether stabilizer used further as a stabilizer is described. In the present invention, the molecular weight of the thioether stabilizer that can be added to the cycloolefin resin is preferably 500 or more.
As the thioether-based stabilizer, Sumilizer TPL, TPM, TPS, TDP, and Adeka Stub AO-412S, which are sold by Asahi Denka Kogyo Co., Ltd., are available from Sumitomo Chemical Co., Ltd.

(Epoxy stabilizer)
The epoxy stabilizer acts as an acid scavenger. Specifically, an epoxy compound as an acid scavenger described in US Pat. No. 4,137,201 can be employed. . Epoxy compounds as such acid scavengers are known in the art, and are derived by condensation of various polyglycol diglycidyl ethers, particularly about 8 to 40 moles of ethylene oxide per mole of polyglycol. Glycol, diglycidyl ether of glycerol, metal epoxy compounds (such as those conventionally used in and together with vinyl chloride polymer compositions), epoxidized ether condensation products, diphenols of bisphenol A Glycidyl ether (ie, 4,4′-dihydroxydiphenyldimethylmethane), epoxidized unsaturated fatty acid ester (especially an ester of a fatty acid having 2 to 22 carbon atoms and an alkyl of 4 to 2 carbon atoms (eg , Butyl epoxy stealey And epoxidized vegetable oils and other unsaturated natural oils (sometimes these are epoxidized natural glycerides, represented by compositions such as epoxidized soybean oil, etc.) Or unsaturated fatty acids, which generally contain 12 to 22 carbon atoms))). Particularly preferred are commercially available epoxy group-containing epoxide resin compounds EPON 815c and epoxidized ether oligomer condensation products.
As the epoxy stabilizer used in the present invention, a compound having an aliphatic, aromatic, alicyclic, aromatic aliphatic or heterocyclic structure and having an epoxy group as a side chain is also useful. The epoxy group is preferably bonded to the residue of the molecule by an ether or ester bond as a glycidyl group or is an N-glycidyl derivative of a heterocyclic amine, amide or imide. These types of epoxy compounds are widely known and are readily available as commercial products. Specifically, it is described in detail in [0096] to [0112] of JP-A-11-189706.
Among these, more preferably, ET-4) epoxidized octyl linoleate, ET-6) epoxidized ricinoleate, ET-7) epoxidized soybean oil fatty acid octyl, ET-8) epoxidized soybean oil, ET-9 Epoxidized linseed oil, particularly preferably ET-8) epoxidized soybean oil, ET-9) epoxidized linseed oil. These epoxy materials are available as ADK STAB O-130P and ADK STAB O-180A (Asahi Denka Kogyo Co., Ltd.).

(Tin-based stabilizer)
Any known tin-based stabilizer can be used as the tin-based stabilizer. Specific examples of preferable tin-based stabilizers include octyl tin maleate polymer, monostearyl tin tris (isooctyl thioglycolate), and dibutyl tin dilaurate.

(Acid scavenger)
The cycloolefin resin of the present invention preferably contains an acid scavenger.
Any acid scavenger useful in the present invention can be used without limitation as long as it is a compound that reacts with an acid to inactivate the acid, and is described in U.S. Pat. No. 4,137,201. Compounds having an epoxy group are preferred. Epoxy compounds as such acid scavengers are known in the art and are derived by condensation of various polyglycol diglycidyl ethers, particularly about 8-40 moles of ethylene oxide per mole of polyglycol. Glycol, diglycidyl ether of glycerol, metal epoxy compounds (such as those conventionally used in and together with vinyl chloride polymer compositions), epoxidized ether condensation products, diphenols of bisphenol A Glycidyl ether (i.e., 4,4'-dihydroxydiphenyldimethylmethane), epoxidized unsaturated fatty acid ester (especially an ester of an alkyl of about 4 to 2 carbon atoms of a fatty acid of 2 to 22 carbon atoms (e.g. butyl Epoxy stearate And epoxidized vegetable oils and other unsaturated natural oils (sometimes these are epoxidized natural glycerides, which can be represented and exemplified by compositions of various epoxidized long chain fatty acid triglycerides and the like (eg, epoxidized soybean oil and the like) Or unsaturated fatty acids, which generally contain 12 to 22 carbon atoms). Moreover, EPON 815C can also be preferably used as a commercially available epoxy group-containing epoxide resin compound.
Furthermore, examples of acid scavengers that can be used other than the above include oxetane compounds, oxazoline compounds, organic earth salts of alkaline earth metals and acetylacetonate complexes, and paragraphs 68 to 105 of JP-A-5-194788. Is included.
In addition, although an acid scavenger may be called an acid scavenger, an acid capture agent, an acid catcher, etc., in this invention, it can use without a difference by these names.
The acid scavenger in the film-forming material used in the present invention can be selected from at least one of the above, and the amount added is 0.001 mass with respect to the mass of the cycloolefin resin. % To 5% by mass is preferable, more preferably 0.005% to 3% by mass, and still more preferably 0.01% to 1% by mass.

(UV absorber)
The cycloolefin resin of the present invention preferably contains one or more ultraviolet absorbers. From the viewpoint of preventing deterioration of the liquid crystal, the ultraviolet absorbent is preferably excellent in the ability to absorb ultraviolet light having a wavelength of 380 nm or less and having little absorption of visible light having a wavelength of 400 nm or more from the viewpoint of liquid crystal display properties. Examples include oxybenzophenone compounds, benzotriazole compounds, salicylic acid ester compounds, benzophenone compounds, cyanoacrylate compounds, nickel complex compounds, and the like. Particularly preferred ultraviolet absorbers are benzotriazole compounds and benzophenone compounds. Among these, a benzotriazole-based compound is preferable because unnecessary coloring with respect to the cycloolefin resin is small. These are disclosed in JP-A-60-235852, JP-A-3-199201, 5-1907073, 5-194789, 5-271471, 6-107854, 6-118233, 6 -148430, 7-11056, 7-11055, 7-11056, 8-29619, 8-239509, and JP-A-2000-204173. The addition amount is preferably 0.01 to 2% by mass, and more preferably 0.01 to 1.5% by mass, based on the melt (melt) to be prepared.
Moreover, as a polymeric ultraviolet absorber useful for this invention, the polymer containing the polymeric ultraviolet absorber described in Unexamined-Japanese-Patent No. 6-148430 and the ultraviolet absorber monomer can be used. The weight average molecular weight of such a polymer is preferably 2000 to 30000, and more preferably 5000 to 20000. In the polymer derived from the ultraviolet absorbing monomer, the content of the ultraviolet absorbing monomer is preferably 1 to 70% by mass, and more preferably 5 to 60% by mass.
As a commercially available ultraviolet absorber monomer that can be used in the present invention, 1- (2-benzotriazole) -2-hydroxy-5- (2-vinyloxycarbonylethyl) benzene, reactive ultraviolet ray manufactured by Otsuka Chemical Co., Ltd. There is 1- (2-benzotriazole) -2-hydroxy-5- (2-methacryloyloxyethyl) benzene of the absorber RUVA-93 or similar compounds. A polymer or copolymer obtained by singly or copolymerizing these is also preferably used, but is not limited thereto. For example, PUVA-30M manufactured by Otsuka Chemical Co., Ltd. is also preferably used as a commercially available polymer ultraviolet absorber. Two or more ultraviolet absorbers may be used.
The following commercially available products can also be used as these ultraviolet absorbers. The benzotriazole series includes TINUBIN P (Ciba Specialty Chemicals), TINUBIN 234 (Ciba Specialty Chemicals), TINUBIN 320 (Ciba Specialty Chemicals), TINUBIN 326 (Ciba Specialty Chemicals) TINUBIN 327 (manufactured by Ciba Specialty Chemicals), TINUBIN 328 (manufactured by Ciba Specialty Chemicals), Sumisorb 340 (manufactured by Sumitomo Chemical), ADK STAB LA-31 (manufactured by Asahi Denka Kogyo Co., Ltd.), etc. . Further, as benzophenone-based ultraviolet absorbers, Seasorb 100 (manufactured by Sipro Kasei Co., Ltd.), Seasorb 101 (manufactured by Sipro Kasei Co., Ltd.), Seasorb 101S (manufactured by Sipro Kasei Co., Ltd.), Seasorb 102 (manufactured by Sipro Kasei Co., Ltd.), Seasorb 103 (Sipro Kasei) Kasei Co., Ltd.), Adeka Stub LA-51 (Asahi Denka Kogyo Co., Ltd.), Chemisorp 111 (Chemipro Kasei Co., Ltd.), UVINUL D-49 (BASF Corp.) and the like. Examples of the oxalic acid anilide UV absorber include TINUBIN 312 (manufactured by Ciba Specialty Chemicals) and TINUBIN 315 (manufactured by Ciba Specialty Chemicals). Furthermore, as a salicylic acid ultraviolet absorber, Seasorb 201 (manufactured by Sipro Kasei Co., Ltd.) and Seasorb 202 (manufactured by Sipro Kasei Co., Ltd.) are marketed, and as a cyanoacrylate ultraviolet absorber, Seasorb 501 (manufactured by Sipro Kasei Co., Ltd.), UVINUL N-539 (BASF) is available. Among these, ADK STAB LA-31 is particularly preferable.
The amount of the ultraviolet absorber and the ultraviolet absorbing polymer used in the present invention is not uniform depending on the type of compound, usage conditions, etc., but in the case of an ultraviolet absorber, 0.2 to about 0.2 to 1 m ² of the optical film. 3.0 g is preferable, 0.4 to 2.0 g is more preferable, and 0.5 to 1.5 is more preferable. Moreover, when it is a ultraviolet absorption polymer, 0.6-9.0g per 1 m < ² > of optical films is preferable, 1.2-6.0 are more preferable, 1.5-3.0 are further more preferable.

(Hindered amine light stabilizer)
Light stabilizers include hindered amine light stabilizer (HALS) compounds, which are known compounds, such as columns 5-11 of US Pat. No. 4,619,956 and US Pat. , 839,405, as described in columns 3 to 5, including 2,2,6,6-tetraalkylpiperidine compounds, or acid addition salts thereof or complexes of them with metal compounds It is. These are commercially available from Asahi Denka as ADK STAB LA-57, LA-52, LA-67, LA-62, LA-77, and TINUVIN 765, 144 from Ciba Specialty Chemicals. .
These hindered amine light-resistant stabilizers can be used alone or in combination of two or more, and used in combination with these hindered amine light-resistant stabilizers and additives such as plasticizers, acid scavengers, and UV absorbers. Alternatively, it may be introduced into a part of the molecular structure of the additive. The blending amount is appropriately selected within a range that does not impair the object of the present invention, but is preferably 0.01 to 10 parts by mass, more preferably 0.02 to 100 parts by mass of the cycloolefin resin according to the present invention. 5 parts by mass, particularly preferably 0.05 to 3 parts by mass. These may be added at any stage of the melt (melt) production process, and a process of adding an additive may be added at the end of the melt production process (melt preparation process).

(Plasticizer)
Addition of a compound known as a plasticizer to the cycloolefin resin film of the present invention is preferable from the viewpoint of film modification such as improvement of mechanical properties, imparting flexibility, imparting water absorption resistance, and reducing moisture permeability. As the plasticizer used in the present invention, for example, phosphate ester derivatives and carboxylic acid ester derivatives are preferably used. Further, a polymer obtained by polymerizing an ethylenically unsaturated monomer having a weight average molecular weight of 500 to 10,000 described in JP-A-2003-12859, an acrylic polymer, an acrylic polymer having an aromatic ring in the side chain, or a cyclohexyl group An acrylic polymer having a side chain is also preferably used.
The plasticizer may be a liquid or a solid, and is preferably colorless due to restrictions on the composition. Thermally, it is preferably stable at a higher temperature, and the decomposition start temperature is preferably 150 ° C. or higher, more preferably 200 ° C. or higher. The addition amount may be as long as optical properties and mechanical properties are not adversely affected, and the blending amount is appropriately selected within the range not impairing the object of the present invention, and is preferably set to 0.1 parts by weight with respect to 100 parts by mass of the cycloolefin resin according to the present invention. It is 01-30 mass parts, More preferably, it is 0.1-20 mass parts. 0.2-12 mass% is especially preferable.

(Matting agent)
It is preferable to add fine particles as a matting agent. The fine particles used in the present invention include silicon dioxide, titanium dioxide, aluminum oxide, zirconium oxide, calcium carbonate, talc, clay, calcined kaolin, calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and Mention may be made of calcium phosphate.
These fine particles usually form secondary particles having an average particle size of 0.1 to 3.0 μm, and these fine particles exist in the film as aggregates of primary particles, and 0.1 to 0.1 μm on the film surface. An unevenness of 3.0 μm is formed. The secondary average particle size is preferably 0.2 μm to 1.5 μm, more preferably 0.4 μm to 1.2 μm, and even more preferably 0.6 μm to 1.1 μm. For the primary and secondary particle sizes, the particles in the film were observed with a scanning electron microscope, and the diameter of a circle circumscribing the particles was defined as the particle size. In addition, 200 particles were observed at different locations, and the average value was taken as the average particle size.
The amount of the fine particles is preferably 0.01 to 0.8 parts by mass, more preferably 0.02 to 0.5 parts by mass with respect to 100 parts by mass of the cycloolefin resin. More preferably, it is 0.03-0.5 mass%. Fine particles containing silicon are preferable because they can reduce turbidity, and silicon dioxide is particularly preferable. The fine particles of silicon dioxide preferably have a primary average particle size of 20 nm or less and an apparent specific gravity of 70 g / liter or more. Those having an average primary particle size as small as 5 to 16 nm are more preferred because they can reduce the haze of the film. The apparent specific gravity is preferably 90 to 200 g / liter or more, and more preferably 100 to 200 g / liter or more. A larger apparent specific gravity is preferable because a high-concentration dispersion can be produced, and haze and aggregates are improved.
As fine particles of silicon dioxide, for example, commercially available products such as Aerosil R972, R972V, R974, R812, 200, 200V, 300, R202, OX50, TT600 (above Nippon Aerosil Co., Ltd.) can be used. The fine particles of zirconium oxide are commercially available under the trade names of Aerosil R976 and R811 (manufactured by Nippon Aerosil Co., Ltd.), and can be used.
Among these, preferably, Aerosil 200V and Aerosil R972V are fine particles of silicon dioxide having a primary average particle size of 20 nm or less and an apparent specific gravity of 70 g / liter or more. The effect of lowering the coefficient of friction is large while keeping the turbidity of the water low.

(Other additives)
Optical modifiers, surfactants, and odor trapping agents (such as amines) can be added. These details are disclosed in the Japanese Society for Invention and Innovation Technique No. 2001-1745 (issued March 15, 2001, Invention Association), p. Materials described in detail in 17-22 are preferably used.
As the infrared absorbing dye, for example, those disclosed in JP-A No. 2001-194522 can be used, and as the ultraviolet absorber, for example, those described in JP-A No. 2001-151901 can be used. It is preferable to contain 001-5 mass%.
Examples of the optical adjusting agent include a retardation adjusting agent. For example, those described in JP 2001-166144 A, JP 2003-344655 A, JP 2003-248117 A, and JP 2003-66230 A are used. Accordingly, in-plane retardation (Re) and thickness direction retardation (Rth) can be controlled. A preferable addition amount is 0 to 10% by mass, more preferably 0 to 8% by mass, and further preferably 0 to 6% by mass.

《Filming》
Below, the manufacturing method of the cycloolefin resin film of this invention is described in detail. In addition, the cycloolefin resin film of this invention is not limited to what was manufactured by these methods. (1) Pelletization The cycloolefin resin and the additive are preferably mixed and pelletized prior to melt film formation.
In the pelletization, the cycloolefin resin and the additive are preferably dried in advance, but drying can be substituted by using a vented extruder. In the case of drying, as the drying method, a method of heating at 90 ° C. for 8 hours or more in a heating furnace can be used, but not limited thereto. Pelletization can be performed by melting the cycloolefin resin and the additive at 150 ° C. to 280 ° C. using a twin-screw kneading extruder, then extruding the noodle into a solid and cutting it in water. Further, pelletization may be performed by an underwater cutting method or the like that is cut while being directly extruded from a die after being melted by an extruder.
Any known single-screw extruder, non-meshing counter-rotating twin-screw extruder, meshing-type counter-rotating twin-screw extruder, meshing co-direction as long as the melter kneading is sufficient A rotary twin screw extruder or the like can be used.

The size of the pellets is preferably cross-sectional area of 1 mm ² to 300 mm ^2, a length of 1Mm～30mm, cross-sectional area 2 mm ² 100 mm ^2, and more preferably the length is 1.5mm~10mm .
Moreover, when pelletizing, the said additive can also be injected | thrown-in from the raw material input port and vent port in the middle of an extruder.

The number of revolutions of the extruder is preferably 10 rpm to 1000 rpm, more preferably 20 rpm to 700 rpm, and even more preferably 30 rpm to 500 rpm. A rotational speed of 10 rpm or more is preferable because the residence time does not become too long, and the molecular weight decreases due to thermal deterioration or the yellowishness tends to be deteriorated. Further, when the rotation speed is 1000 rpm or less, it becomes difficult for molecules to be cut by shearing, and problems such as a decrease in molecular weight and an increase in the generation of cross-linked gel are less likely to occur.
The extrusion residence time in pelletization is preferably 10 seconds to 30 minutes, more preferably 15 seconds to 10 minutes, and even more preferably 30 seconds to 3 minutes. If sufficient melting is possible, a shorter residence time is preferable in terms of suppressing resin deterioration and yellowing.

(2) Drying It is preferable to dry the moisture in the pellets prior to melt film formation so that the moisture content is 0.1% by mass or less, more preferably 0.01% by mass or less. A known drying method can be adopted for drying the pellet-shaped resin. Examples thereof include a dryer that circulates dehumidified air, a hot air dryer, a vacuum dryer, an ultrasonic dryer, a high-frequency dryer, and an infrared dryer. The drying temperature for this is preferably 40 to 180 ° C, more preferably 60 to 160 ° C, and even more preferably 80 to 140 ° C. Although the drying efficiency increases as the amount of drying air increases, the amount of air necessary for drying 100 kg of resin per hour is preferably 10 to 200 m ³ / hour, more preferably considering water removal efficiency and economy. Is 50 to 125 m ³ / hour. The dew point of the drying air is preferably −60 ° C. to 0 ° C., and more preferably −40 ° C. to −20 ° C. in consideration of drying efficiency and economy.

(3) Melt extrusion Dry cycloolefin resin is fed into the cylinder from the feed port of the extruder. The screw compression ratio of the extruder is preferably 1.5 to 4.5, more preferably 2.5 to 4.0. Here, the screw compression ratio is represented by a volume ratio between the supply unit A and the measurement unit C, that is, a volume per unit length of the supply unit A ÷ a volume per unit length of the measurement unit C. L (screw length) / D (screw diameter) is preferably 20 to 70, more preferably 24 to 50. The extrusion temperature of cycloolefin resin becomes like this. Preferably it is 210 to 280 degreeC, More preferably, it is 220 to 260 degreeC, More preferably, it is 240 to 260 degreeC. The barrel of the extruder is preferably heated and melted with a heater divided into 3 to 20.
A wide variety of known screws such as full flight, mudock, and dalmage can be used. Specifically, in consideration of uniform plasticization, prevention of occurrence of stagnant portions, and thermal deterioration due to shear heat generation, an appropriate screw design may be appropriately combined.
In order to prevent the oxidation of the resin, it is more preferable that the inside of the extruder is carried out in an inert (nitrogen or the like) air stream or while being evacuated using a vented extruder.

(4) Filtration It is preferable to perform a so-called breaker plate type filtration in which a filter medium is provided at the outlet of the extruder for filtering foreign matter in the resin and avoiding damage to the gear pump due to foreign matter. At this time, it can be achieved by adjusting the pore diameter of the filter medium and the flow rate of the molten resin as described above.
In order to filter foreign matter with higher accuracy, it is preferable to provide a filtration device incorporating a so-called leaf type disk filter after passing through the gear pump. Filtration can be performed by providing one filtration section, or multistage filtration performed by providing a plurality of places. The filtration accuracy of the filter medium is preferably higher, but the filtration accuracy is preferably 15 μm to 3 μm, more preferably 10 μm to 3 μm, because of an increase in the filtration pressure due to the pressure resistance of the filter medium or clogging of the filter medium. In particular, when using a leaf-type disk filter device that finally filters foreign matter, it is preferable to use a filter medium with high filtration accuracy in terms of quality, and it is adjusted by the number of loaded sheets to ensure the suitability of pressure resistance and filter life. It is possible to The type of filter medium is preferably a steel material because it is used under high temperature and high pressure. Among steel materials, it is more preferable to use stainless steel, steel, etc., and stainless steel is particularly preferable from the viewpoint of corrosion. Further preferred. As a configuration of the filter medium, for example, a sintered filter medium formed by sintering metal long fibers or metal powder can be used in addition to a knitted wire, and a sintered filter medium is preferable from the viewpoint of filtration accuracy and filter life.

(5) Gear pump In order to improve the thickness accuracy, it is important to reduce the fluctuation of the discharge amount. A gear pump is provided between the extruder and the die, and a certain amount of cycloolefin resin is supplied from the gear pump. That is effective. A gear pump is accommodated in a state where a pair of gears composed of a drive gear and a driven gear are engaged with each other, and the drive gear is driven to engage and rotate the two gears, so that a melted state is generated from the suction port formed in the housing. The resin is sucked into the cavity, and a predetermined amount of cycloolefin resin is discharged from the discharge port formed in the housing. Even if there is a slight fluctuation in the resin pressure at the front end of the extruder, the fluctuation is absorbed by using a gear pump, the fluctuation in the resin pressure downstream of the film forming apparatus becomes very small, and the thickness fluctuation is improved. By using a gear pump, it is possible to keep the fluctuation range of the resin pressure in the die portion within ± 1%.

  In order to improve the quantitative supply performance by the gear pump, a method of controlling the pressure before the gear pump to be constant by changing the number of rotations of the screw can also be used. In addition, a high-precision gear pump using three or more gears that eliminates gear fluctuations of the gear pump is also effective.

  Other advantages of using a gear pump are that the pressure at the tip of the screw can be reduced to form a film, reducing energy consumption, preventing rise in resin temperature, improving transport efficiency, reducing residence time in the extruder, Shortening of L / D can be expected. In addition, when using a filter for removing foreign matter, if there is no gear pump, the amount of cycloolefin resin supplied from the screw may fluctuate as the filtration pressure increases. It can be solved by using it. On the other hand, the disadvantage of the gear pump is that the length of the equipment becomes longer depending on the equipment selection method, the residence time of the cycloolefin resin becomes longer, and the molecular chain of the cycloolefin resin is broken by the shear stress of the gear pump part. Sometimes it needs attention.

The preferred residence time of the cycloolefin resin from the time when the cycloolefin resin enters the extruder to the time when it exits the die is 2 minutes to 60 minutes, more preferably 3 minutes to 40 minutes, and even more preferably 4 minutes. ~ 30 minutes.
Since the flow of the polymer for bearing circulation of the gear pump is deteriorated, the polymer seal in the drive part and the bearing part is deteriorated, and there is a problem that the fluctuation of the metering and liquid feeding pressure is increased. A gear pump design (especially clearance) that matches the melt viscosity is required. In some cases, the staying part of the gear pump causes deterioration of the cycloolefin resin, and therefore a structure with as little staying as possible is preferable. The polymer pipes and adapters that connect the extruder and gear pump or gear pump and die, etc. must also be designed with as little stagnation as possible, and in order to stabilize the extrusion pressure of cycloolefin resins with high melt viscosity temperature dependence. It is preferable to make the temperature fluctuation as small as possible. Generally, a band heater having a low equipment cost is often used for heating the polymer tube, but it is more preferable to use an aluminum cast heater with less temperature fluctuation. Further, in the extruder as described above, it is preferable that the barrel of the extruder is heated and melted with a heater divided into 3 to 20.

(6) Die The cycloolefin resin is melted by the extruder configured as described above, and the molten resin is continuously sent to the die via a filter and a gear pump as necessary. As long as the die is designed so that the molten resin stays in the die, any type of commonly used T die, fishtail die, and hanger coat die may be used. Moreover, there is no problem to insert a static mixer for improving the uniformity of the cycloolefin resin temperature immediately before the T die. The clearance of the T-die outlet portion is generally preferably 1.0 to 5.0 times, more preferably 1.2 to 3 times, and even more preferably 1.3 to 2 times the film thickness. By making the lip clearance 1.0 times or more of the film thickness, a more excellent sheet can be obtained by film formation. Moreover, it exists in the tendency for the thickness precision of a sheet to improve by making lip clearance 5.0 times or less of film thickness. The die is a very important facility for determining the thickness accuracy of the film, and is preferably one that can strictly control the thickness adjustment. The interval for adjusting the thickness is preferably 50 mm or less, more preferably 35 mm or less, and preferably 25 mm or less. Further, in order to improve the uniformity of the film-forming film, it is important to design as little as possible of the temperature unevenness of the die and the flow velocity unevenness in the width direction. An automatic thickness adjustment die that measures the downstream film thickness, calculates the thickness deviation, and feeds back the result to the die thickness adjustment is also effective in reducing the thickness fluctuation in long-term continuous production.
For production of a film, a single-layer film forming apparatus with a low equipment cost is generally used. However, in some cases, a film having two or more types of structures can also be manufactured using a multilayer film forming apparatus in order to provide a functional layer on an outer layer. Is possible. In general, the functional layer is preferably thinly laminated on the surface layer, but the layer ratio is not particularly limited.

(7) Casting Under the above conditions, the molten resin extruded from the die onto the sheet is cooled and solidified on the casting drum to obtain a film.
In the present invention, it is preferable to improve the adhesion between the casting drum and the melt-extruded sheet using a method such as electrostatic application on the casting drum, air knife method, air chamber method, vacuum nozzle method, touch roll method, etc. Of these, the touch roll method described above is preferably used.
The touch roll method forms a film surface by placing a touch roll on a casting drum. At this time, the touch roll is preferably not elastic and usually elastic. However, an elastically deformable member (rubber or the like) covered with a very thin metal is not preferable because the surface pressure cannot be increased. This is because the amount of deformation of the touch roll is large, the contact area with the cast roll becomes too large, and sufficient surface pressure cannot be produced. The thickness of the touch roll of the present invention is preferably 0.5 mm to 7 mm, more preferably 1.1 to 6 mm, and further preferably 1.5 to 5 mm. The touch roll and casting roll preferably have a mirror surface, and the arithmetic average height Ra is preferably 100 nm or less, more preferably 50 nm or less, and further preferably 25 nm or less. The surface pressure of the touch roll is preferably 0.1 MPa to 10 MPa, more preferably 0.2 MPa to 7 MPa, and further preferably 0.3 MPa to 5 MPa. The surface pressure referred to here is a value obtained by dividing the force pressing the touch roll by the contact area between the cycloolefin resin film and the touch roll.
The touch roll may be installed on a metal shaft and a heat medium (fluid) may be passed between them. An elastic layer is provided between the outer cylinder and the metal shaft, and the heat medium (fluid) is filled between the outer cylinders. Can be mentioned. The temperature of the touch roll is preferably more than (Tg-10) ° C and not more than (Tg + 30) ° C, more preferably (Tg-7) ° C to (Tg + 20) ° C, still more preferably (Tg-5) ° C to (Tg + 10). ) ° C. The temperature of the casting roll is preferably in the same temperature range.
Specific examples of the touch roll include, for example, JP-A-11-314263, JP-A-11-235747, JP-A-2002-36332, International Publication WO97 / 28950, and JP-A-2004-216717. The touch roll described in JP-A-2003-145609 can be used.

  More preferably, a plurality of casting drums (rolls) are used for slow cooling. Of these, the touch roll is preferably used so as to touch the first casting roll on the most upstream side (closer to the die). In general, it is relatively common to use three cooling rolls, but this is not a limitation. The diameter of the roll is preferably 50 mm to 5000 mm, more preferably 100 mm to 2000 mm, and still more preferably 150 mm to 1000 mm. The interval between the plurality of rolls is preferably 0.3 mm to 300 mm, more preferably 1 mm to 100 mm, and even more preferably 3 mm to 30 mm between the surfaces. The line speed on the uppermost stream side of the cast roll is preferably 20 m / min to 70 m / min.

(8) Winding After peeling off from the casting drum, it winds up through a nip roll.
The film forming width is preferably 0.7 m to 5 m, more preferably 1 m to 4 m, and still more preferably 1.3 m to 3 m.

It is also preferable to trim both ends before winding. As the trimming cutter, any type of rotary cutter, shear blade, knife, or the like may be used. Any material such as carbon steel or stainless steel may be used. In general, it is preferable to use a cemented carbide blade or a ceramic blade because the life of the blade is long and the generation of chips is suppressed. The portion cut off by trimming may be crushed and used again as a raw material.
It is also preferable to perform a thickness increasing process (knurling process) at one or both ends. The height of the unevenness by the thicknessing process is preferably 1 μm to 200 μm, more preferably 10 μm to 150 μm, and still more preferably 20 μm to 100 μm. Thickening processing may be convex on both sides or convex on one side. The width of the thickness increasing process is preferably 1 mm to 50 mm, more preferably 3 mm to 30 mm, and still more preferably 5 mm to 20 mm. Extrusion can be performed at room temperature to 300 ° C.

The cycloolefin resin film thus formed may be stretched as it is (online stretching), or after being wound up once, it may be sent out again and stretched (offline stretching).
At the time of winding, it is also preferable to attach a lami film on at least one side from the viewpoint of preventing scratches. The thickness of the laminated film is preferably 5 μm to 200 μm, more preferably 10 μm to 150 μm, still more preferably 10 μm to 120 μm, and particularly preferably 15 μm to 100 μm.

The winding tension is preferably 1 kg / m width to 50 kg / width, more preferably 2 kg / m width to 40 kg / width, and even more preferably 3 kg / m width to 20 kg / width. When the winding tension is smaller than 1 kg / m width, it is difficult to wind the film uniformly. On the other hand, when the winding tension exceeds 50 kg / width, the film becomes tightly wound, not only the appearance of the winding is deteriorated, but also the bump portion of the film extends due to the creep phenomenon, and the film wave This is not preferable because it causes a cause or residual birefringence due to the elongation of the film. It is preferable that the winding tension is detected by tension control in the middle of the line and wound while being controlled so as to have a constant winding tension. If there is a difference in film temperature depending on the location of the film production line, the length of the film may be slightly different due to thermal expansion. It is necessary to prevent tension.
The winding tension can be wound at a constant tension by controlling the tension control. However, it is more preferable that the winding tension is tapered according to the wound diameter to obtain an appropriate winding tension. Generally, the tension is gradually reduced as the winding diameter increases, but in some cases, it may be preferable to increase the tension as the winding diameter increases.

(9) Recovery A scrap film is generated during the trimming step for adjusting the formed unstretched film or stretched film to the product size or when adjusting the film forming conditions. Since the amount of generation reaches about 5 to 30% of the input raw material, it is extremely important from the viewpoint of cost and environment to grind the waste film and mix it with a new raw material or to reuse it alone.
(Crushing film)
The generated scrap film is preferably a continuous strip-like form in a continuous strip shape and sent to a pulverizer by a pinch roll or a blower and pulverized into strips, and once wound up by a winder, Alternatively, a method of pulverizing with an offline pulverizer may be used. In the case of a film in which the thermal degradation of the film edge is severe, only the film edge may be slit and removed.
Crusher, crusher (cut / shear) by contact with fixed blade and rotary blade, crusher that cuts into strips like shredder, or crusher that uses shear force like cutter mill (fine crusher) Cutter), blower cutter, hammer mill, etc. can be used. As the grinding blade, a flat blade, a comb blade, a rotary blade, or the like can be used.
The size of the film to be pulverized is preferably 0.1 to 30 mm, more preferably 0.5 to 15 mm, and still more preferably about 1 to 10 mm. If the pulverized size is too large, the pipe is likely to be clogged. On the other hand, if the pulverized size is too small, it tends to adhere to the inside of the pipe. The pulverization size can be adjusted by the hole diameter of the mesh to be passed.
In addition, multistage crushing is also effective, in which the primary crusher is crushed to a slightly larger size and the secondary crusher is crushed to the target size. Furthermore, in order to prevent the pulverized film from blocking due to shear heat generation during pulverization, it is effective to use a pulverizer having a structure that hardly generates heat and a cooling function.
In order to prevent metal parts from coming into contact with each other during pulverization and generating metal powder, it is effective to remove them with a metal removing device having a magnetic force. Moreover, you may remove the dust adhering to film waste by washing | cleaning and drying.
The pulverized film is preferably transported by gas under pressure or reduced pressure, and may be transported by a conveyor or a rotary feeder. In addition, since the pulverized film has a small bulk specific gravity, there is no problem even if re-pelletization is performed using a compressor or a single-screw or twin-screw extruder.

(Drying the pulverized raw material)
The pulverized film does not need to be dried if it is immediately returned to the raw material in-line using a pulverizer that prevents moisture absorption, but normally it needs to be dried to obtain a predetermined moisture content. Hot air dryers and dry air dryers A vacuum dryer, an ultrasonic dryer, an infrared dryer or the like can be used.
(Transportation and supply of crushed raw materials)
The pulverized and dried film may be supplied to the raw material tank through an air feed pipe, mixed with the virgin raw material, and supplied to the hopper. Further, the pulverized film and the virgin raw material may be separately weighed and supplied to the extruder. The mixing ratio of the pulverized film raw material and the virgin raw material is preferably 1:99 to 70:30, more preferably 5:95 to 50:50, by weight. Thereby, even if the bulk density of a pulverized film and a virgin raw material differs, the supply stability to an extruder is favorable and preferable. However, when re-pelletizing, if there is no problem in film physical properties, it is not necessary to be in the above range, and it is possible to mix at an arbitrary blending ratio.

<< Extension process >>
The melt-formed cycloolefin resin film may be subjected to transverse stretching and / or longitudinal stretching, and may be subjected to relaxation treatment in combination with these. These can be implemented by, for example, the following combinations.
(1) transverse stretching (2) transverse stretching → relaxation treatment (3) longitudinal stretching → lateral stretching (4) longitudinal stretching → lateral stretching → relaxation treatment (5) longitudinal stretching → relaxation treatment → lateral stretching → relaxation treatment (6) transverse Stretching → Longitudinal stretching → Relaxation treatment (7) Transverse stretching → Relaxation treatment → Longitudinal stretching → Relaxation treatment (8) Longitudinal stretching → Transverse stretching → Longitudinal stretching (9) Longitudinal stretching → Transverse stretching → Longitudinal stretching → Relaxation treatment (10) Longitudinal Stretching (11) Longitudinal stretching → relaxation treatment Among these, (1) to (4) and (10) to (11) are more preferable, and (2), (4) and (11) are more preferable. ). Among these, (1) to (4) are more preferable, and (2) and (4) are more preferable.
Furthermore, by such uniform stretching, the molecules that have been rounded in the film can be efficiently stretched. As a result, entanglement can be formed between the molecules, and the breaking strength can be improved.

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

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

The aspect ratio exceeds 2 and is preferably 50 or less, more preferably 3 to 40, and still more preferably 4 to 20. The stretching temperature is preferably (Tg-5 ° C) to (Tg + 100) ° C, more preferably (Tg) to (Tg + 50) ° C, and still more preferably (Tg + 5) to (Tg + 30) ° C. The draw ratio is preferably 1.01 to 3 times, more preferably 1.02 to 2.0 times, and still more preferably 1.05 to 1.4 times. Such long span stretching may be performed in multiple stages with three or more pairs of nip rolls as long as the longest aspect ratio is within the above range.
The draw ratio here is determined using the following formula.
Stretch ratio = (Length after stretching) / (Length before stretching)
Such long span stretching may be performed by heating the film between two pairs of nip rolls separated by a predetermined distance. The heating method is a heater heating method (infrared heater, halogen heater, panel heater, etc. above or below the film). Or heating by radiant heat) or a zone heating method (heating in a zone in which hot air or the like is blown and adjusted to a predetermined temperature) may be used. In the present invention, the zone heating method is preferable from the viewpoint of uniformity of the stretching temperature. At this time, the nip roll may be installed in the stretching zone or out of the zone, but it is preferably out of the zone in order to prevent the film and the nip roll from sticking. It is also preferable to preheat the film before such stretching, and the preheating temperature is (Tg-80) ° C to (Tg + 100) ° C.

By such stretching, the Re value is preferably 0 to 200 nm, more preferably 10 to 200 nm, still more preferably 15 nm to 100 nm, and the Rth value is, for example, 0 to 600 nm, preferably 30 to 500 nm, more preferably 50 It is -400 nm, More preferably, it is 70-350 nm. By this stretching method, the ratio of Rth and Re (Rth / Re) can be 0.4 to 0.6, more preferably 0.45 to 0.55. Furthermore, by this stretching, the variation in Re value and Rth value can be preferably 5% or less, more preferably 4% or less, and still more preferably 3% or less.
With such stretching, the ratio of the film width before and after stretching (film width after stretching / film width before stretching) is preferably 0.5 to 0.9, more preferably 0.6 to 0.85, More preferably, it becomes 0.65-0.83.

(1-2) Short span stretching The aspect ratio (L / W) is preferably more than 0.01 and less than 0.3, more preferably 0.03 to 0.25, still more preferably 0.05 to 0.2. Perform longitudinal stretching (short span stretching). By performing stretching at an aspect ratio (L / W) in such a range, neck-in (shrinkage in the direction orthogonal to stretching accompanying stretching) can be reduced. Although the width and thickness are reduced to compensate for stretching in the stretching direction, such short span stretching suppresses width shrinkage and preferentially reduces the thickness. As a result, the film is compressed in the thickness direction, and the orientation (plane orientation) in the thickness direction proceeds. As a result, Rth, which is a measure of anisotropy in the thickness direction, tends to increase. On the other hand, conventionally, the aspect ratio (L / W) is generally about 1 (0.7 to 1.5). This is usually done by installing a heater for heating between the nip rolls, but if the L / W is too large, the film cannot be heated uniformly with the heater and uneven stretching tends to occur. If the L / W is too small, the heater is stretched. This is because it is difficult to install and cannot be heated sufficiently.
The short span stretching described above can be performed by changing the conveyance speed between two or more pairs of nip rolls, but unlike a normal roll arrangement, the two pairs of nip rolls are slanted (the rotational axes of the front and rear nip rolls are shifted up and down). This can be achieved by arranging.
The stretching temperature is preferably (Tg-5 ° C) to (Tg + 100) ° C, more preferably (Tg) to (Tg + 50) ° C, and still more preferably (Tg + 5) to (Tg + 30) ° C. The preheating temperature is preferably (Tg−80) ° C. to (Tg + 100) ° C.

Here, the long span stretching and the short span stretching will be described in detail.
FIG. 3 is a schematic configuration diagram of the film manufacturing apparatus 10 when a cycloolefin resin film is manufactured by melt film formation when long span stretching is performed.
The film manufacturing apparatus 10 is an apparatus for manufacturing a cycloolefin resin film F that can be used for a liquid crystal display device or the like. The pellet-shaped cycloolefin resin which is the raw material of the cycloolefin resin film F is introduced into the dryer 12 and dried, and then the pellet is extruded by the extruder 14 and supplied to the filter 18 by the gear pump 16. Next, the foreign matter is filtered by the filter 18 and pushed out from the die 20. Thereafter, the film is sandwiched between the cast drum 28 and the touch roll 24 and passes between the cast drum 28 and the roll 26 to be solidified to form an unstretched film Fa having a predetermined surface roughness. And this unstretched film Fa is supplied to the longitudinal stretch part 30 which performs long span stretching.
In the longitudinal stretching section 30, the unstretched film Fa is stretched in the transport direction between the inlet side nip roll 32 and the outlet side nip roller 34 to obtain a longitudinally stretched film Fb. FIG. 4 is an explanatory perspective view of the longitudinal stretching unit 30. The longitudinal stretching aspect ratio (L / W) is determined by the distance L between the inlet-side nip roll 32 and the outlet-side nip roller 34 and the inlet-side nip roll 32. And the width W of the outlet side nip roller 34 in the length direction. Next, the longitudinally stretched film Fb is adjusted to a predetermined preheating temperature by passing through the preheating unit 36 and then supplied to the lateral stretching unit 42.
In the laterally stretched portion 42, the longitudinally stretched film Fb is stretched in the width direction orthogonal to the transport direction to form a laterally stretched film Fc. Then, the transversely stretched film Fc is supplied to the heat fixing unit 44 and wound up by the winding unit 46, whereby the cycloolefin resin film F which is the final product in which the orientation angle and retardation are adjusted is manufactured. The transversely stretched film Fc may be further subjected to heat relaxation treatment after passing through the heat fixing portion 44.

On the other hand, FIG. 5 and FIG. 6 are schematic configuration diagrams of a film manufacturing apparatus 10a in which a longitudinal stretching unit 30a that performs short span stretching is used instead of the longitudinal stretching unit 30 that performs long span stretching shown in FIGS. .
In this film manufacturing apparatus 10a, the unstretched film Fa is preheated to a predetermined temperature by the preheating rolls 33 and 35 and then supplied between the two sets of nip rolls 37 and 39 for longitudinal stretching. In this case, the nip rolls 37 and 39 are disposed in the vicinity of the transport direction of the unstretched film Fa and are disposed so that the height differs by a predetermined distance in the vertical direction. By disposing the nip rolls 37 and 39 in this way, the transport distance of the unstretched film Fa in the longitudinal stretching portion 30a can be secured, and the distance between the mechanisms disposed before and after the longitudinal stretching portion 30a can be shortened. The manufacturing apparatus 10a can be downsized.
6 is a perspective explanatory view of the longitudinally stretched portion 30a, and the longitudinal / aspect ratio (L / W) of the longitudinal stretching is the distance L in the transport direction of the unstretched film Fa nipped by the nip rolls 37 and 39. , And the width W in the length direction of the nip rolls 37 and 39.

(Lateral stretching)
The transverse stretching can be performed using a tenter. That is, the film is stretched by holding both ends in the width direction with clips and widening the film in the lateral direction. At this time, the stretching temperature can be controlled by sending wind at a desired temperature into the tenter. The stretching temperature is preferably (Tg-10) ° C to (Tg + 60) ° C, more preferably (Tg-5) ° C to (Tg + 45) ° C, and further preferably Tg to (Tg + 30) ° C. The stretching ratio (length in the film width direction after stretching / length in the film width direction before stretching) is preferably 1.01 to 3.0 times, more preferably 1.02 to 2.5 times. And more preferably 1.05 to 2.0 times.

By performing preheating before stretching and heat setting after stretching, the Re and Rth distribution after stretching can be reduced, and the variation in orientation angle associated with bowing can be reduced. Either preheating or heat setting may be performed, but both are more preferable. These preheating and heat setting are preferably performed by holding with a clip, that is, preferably performed continuously with stretching.
Preheating is preferably performed at a temperature higher than the stretching temperature by 1 ° C to 50 ° C, more preferably 2 ° C to 40 ° C, and even more preferably 3 ° C to 30 ° C. The preheating time is preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, and still more preferably 10 seconds to 2 minutes. During preheating, it is preferable to keep the width of the tenter substantially constant. Here, “substantially” refers to ± 10% of the width of the unstretched film, for example.
The heat setting is preferably 1 to 50 ° C., more preferably 2 to 40 ° C., and further preferably 3 to 30 ° C. lower than the stretching temperature. More preferably, it is less than the stretching temperature and less than Tg. The preheating time is preferably 1 second to 10 minutes, more preferably 5 seconds to 4 minutes, and still more preferably 10 seconds to 2 minutes. During the heat setting, it is preferable to keep the width of the tenter substantially constant. Here, “substantially” refers to 0% (the same width as the tenter width after stretching) to −10% (shrinking by 10% from the tenter width after stretching = reduced width) of the tenter width after stretching. If the width is wider than the stretched width, residual strain is likely to occur in the film, and it is not preferable because it is likely to increase the variation with time of Re and Rth.
Thus, it is preferable that the heat setting temperature <the stretching temperature <the preheating temperature.
The reason why the variation in orientation angle and Re and Rth can be reduced by such preheating and heat setting is as follows. That is, as shown in FIG. 7, when preheating temperature = stretching temperature = preheating temperature, the film is stretched in the width direction and tends to narrow in the orthogonal direction (longitudinal direction) (neck-in). For this reason, the film before and after transverse stretching is pulled and stress is generated. However, both ends in the width direction are fixed by chucks and are not easily deformed by stress, and the central portion in the width direction is easily deformed. As a result, the stress caused by the neck-in is deformed into a bow shape and bowing occurs. As a result, in-plane Re and Rth unevenness and distribution of orientation axes occur. Therefore, as shown in FIG. 8, by setting the heat setting temperature <stretching temperature <preheating temperature, the temperature on the preheating side (before stretching) is increased, and the temperature on the heat treatment (after stretching) is decreased, so that the neck-in becomes more It occurs on the high temperature side (preheating) with a low elastic modulus, and is less likely to occur on heat treatment (after stretching). As a result, bowing after stretching can be suppressed.

By such stretching, the variation of Re and Rth in the width direction and the longitudinal direction can be preferably 5% or less, more preferably 4% or less, and still more preferably 3% or less. Further, the orientation angle can be preferably 90 ° ± 5 ° or less or 0 ° ± 5 ° or less, more preferably 90 ° ± 3 ° or less or 0 ° ± 3 ° or less, and further preferably 90 ° ± 1 °. Or 0 ° ± 1 ° or less.
The present invention is characterized in that such an effect can be achieved even at high speed stretching, and the effect is remarkably exhibited even at 20 m / min or more, more preferably 25 m / min or more, and even more preferably 30 m / min or more.

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

(Volatile component during stretching)
In the longitudinal stretching and lateral stretching, the volatile components (solvent, moisture, etc.) are preferably 1% by mass or less, more preferably 0.5% by mass or less, and still more preferably 0.3% by mass or less with respect to the resin. Thereby, the axial shift generated during stretching can be further reduced. This is because during the stretching, in addition to the shrinkage stress acting in the direction perpendicular to the stretching, the shrinkage stress accompanying drying acts, and the bowing becomes more prominent.

(Physical properties of cycloolefin resin film)
In the unstretched cycloolefin film of the present invention, Re is preferably 0 to 20 nm and Rth is preferably 0 to 80 nm, Re is preferably 0 to 10 nm, Rth is preferably 0 to 60 nm, Re is 0 to 10 nm, More preferably, Rth is 0 to 30 nm.
The angle θ formed by the film forming direction (longitudinal direction) and the slow axis of Re of the film is preferably closer to 0 °, + 90 °, or −90 °.
The change in humidity of Re ((Re measured at 25 ° C. and 10% RH) − (Re measured at 25 ° C. and 80% RH)) is preferably from 0 nm to 3 nm, and more preferably from 0 nm to 1 nm. The humidity change of Rth ((Rth measured at 25 ° C. and 10%) − (Rth measured at 25 ° C. and 80% RH)) is preferably from 0 nm to 10 nm, and more preferably from 0 nm to 5 nm.
Photoelastic coefficient, MD, is preferably a TD least ^{0.5 × 10 -13 ~10 × 10 -13} (cm 2 / dyn), 1 × 10 -13 ~5 × 10- 13 (cm 2 / dyn ) Is more preferable.
The total light transmittance is preferably 90% to 100%. The haze is preferably 0 to 1%, and more preferably 0 to 0.6%.
The thickness unevenness is preferably 3% or less in both the longitudinal direction and the width direction, and more preferably 2% or less.
Preferably, the modulus in tension is ^{1.5kN / mm 2 ~3.5kN / mm 2} , 1.8kN / mm 2 ~3.0kN / mm 2 is more preferable. The breaking elongation is preferably 1% to 300%.
The glass transition temperature (Tg) is preferably 95 ° C to 185 ° C, more preferably 105 ° C to 165 ° C, and still more preferably 110 ° C to 155 ° C.
The thermal dimensional change at 80 ° C. for 1 day is preferably 1% or less in both the vertical and horizontal directions, and more preferably 0.3% or less.
Water permeability at 40 ° C. 90% relative humidity, preferably 1 to 800 g / m ² · day, and more preferably ² · day 1~400g / m. The equilibrium water content at 25 ° C. and 80% relative humidity is preferably 0.01 to 5% by weight, and 0.01 to 2.5% by weight.
The thermal expansion coefficient is preferably 50 to 180 ppm / ° C, more preferably 100 to 160 ppm / ° C for MD and TD, respectively. The humidity and thermal expansion coefficients of MD and TD are each preferably 0.01 to 10 ppm / ° C, more preferably 0.01 ppm / ° C to 5 ppm / ° C.

(Physical properties of stretched cycloolefin resin film)
It is preferable that Re and Rth of the cycloolefin resin film thus longitudinally stretched, laterally stretched, and longitudinally and laterally satisfy the following formulas (R-1) and (R-2).
Formula (R-1): 0 nm ≦ Re ≦ 200 nm
Formula (R-2): 0 nm ≦ Rth ≦ 600 nm
(In the formula, Re represents in-plane retardation of the cycloolefin resin film, and Rth represents the thickness direction retardation of the cycloolefin resin film.)

  More preferably, 20 nm ≦ Re ≦ 180 nm, 10 nm ≦ Rth ≦ 400 nm, and further preferably 30 nm ≦ Re ≦ 150 nm, 20 nm ≦ Rth ≦ 300 nm.

The angle θ formed by the film forming direction (longitudinal direction) and the slow axis of Re of the film is preferably closer to 0 °, + 90 °, or −90 °. That is, in the case of longitudinal stretching, it is preferably as close to 0 °, preferably 0 ± 3 °, more preferably 0 ± 2 °, and further preferably 0 ± 1 °. In the case of transverse stretching, 90 ± 3 ° or −90 ± 3 ° is preferable, 90 ± 2 ° or −90 ± 2 ° is more preferable, and 90 ± 1 ° or −90 ± 1 ° is more preferable.
The variation of Re and Rth is preferably 0 to 8%, more preferably 0 to 5%, and still more preferably 0 to 3%.
Further, the fluctuations of Re and Rth under storage (changes in Re and Rth before and after 500 hours at 80 ° C .: details will be described later) are preferably 0 to 8%, more preferably 0 to 6%. Preferably it is 0 to 4%.
The thickness of the cycloolefin resin film after stretching is preferably 15 μm to 150 μm, more preferably 20 μm to 100 μm, and still more preferably 30 μm to 80 μm. The thickness unevenness is preferably 3% or less, more preferably 2% or less, and even more preferably 1% or less in both the longitudinal direction and the width direction. By using a thin film, residual strain is less likely to remain in the film after stretching, and retardation changes with time are less likely to occur. This is because when cooling after stretching, if the thickness is thick, the internal cooling is delayed as compared to the surface, and residual strain due to the difference in thermal shrinkage tends to occur.
The thermal dimensional change rate is preferably 0.3% or less, more preferably 0.2% or less, and further preferably 0.1% or less. The thermal dimensional change rate means a dimensional change when heat-treated at 80 ° C. for 5 hours.

<< Processing of cycloolefin resin film >>
The cycloolefin resin film of the present invention thus obtained may be used alone, or may be used in combination with a polarizing plate or the like using the cycloolefin resin film as a base material. Alternatively, a layer having a controlled refractive index (low reflection layer) or a hard coat layer may be provided. These can be achieved by the following steps.
(surface treatment)
Glow discharge treatment, ultraviolet irradiation treatment, corona treatment, flame treatment, acid or alkali treatment can be used. The glow discharge treatment here includes a low temperature plasma treatment performed under a low pressure gas of 10 ^{−3 to} 20 Torr (0.13 to 2700 Pa). Further, plasma treatment under atmospheric pressure is also a preferable glow discharge treatment.
A plasma-excitable gas is a gas that is plasma-excited under the above-described conditions, and examples thereof include chlorofluorocarbons such as argon, helium, neon, krypton, xenon, nitrogen, carbon dioxide, tetrafluoromethane, and mixtures thereof. It is done. Details of these are described in detail on pages 30 to 32 in the Journal of the Invention Association (Technology No. 2001-1745, issued on March 15, 2001, Invention Association). Note that, in the plasma treatment at atmospheric pressure which has been attracting attention in recent years, for example, irradiation energy of 20 to 500 KGy is used under 10 to 1000 Kev, and more preferably irradiation energy of 20 to 300 KGy is used under 30 to 500 Kev.
Of these, glow discharge treatment, corona treatment, and flame treatment are particularly preferred.
It is also preferable to provide an undercoat layer for adhesion to the functional layer. This layer may be coated after the surface treatment or may be coated without the surface treatment. Details of the undercoat layer are described on page 32 of the Japan Society for Invention and Innovation (Public Technical Number 2001-1745, published on March 15, 2001, Japan Institute of Invention).
These surface treatment and undercoating processes can be incorporated at the end of the film forming process, can be performed alone, or can be performed in the functional layer application process described later.

<< Use of the cycloolefin resin film of the present invention >>
The cycloolefin resin film of the present invention is combined with the functional layer described in detail on pages 32 to 45 of the Japan Society for Invention and Technology (Public Technical Number 2001-1745, issued on March 15, 2001, Japan Society of Invention). It is preferable. Among these, application of a polarizing film (polarizing plate), application of an optical compensation layer (optical compensation sheet), and application of an antireflection layer (antireflection film) are preferable. This will be described in order below.

(1) Application of polarizing film (preparation of polarizing plate)
(Material used)
At present, commercially available polarizing films are generally prepared by immersing a stretched polymer in a solution of iodine or dichroic dye in a bath and allowing the iodine or dichroic dye to penetrate into the binder. is there. As the polarizing film, a coating type polarizing film represented by Optiva Inc. can also be used. The iodine and the dichroic dye in the polarizing film develop polarizing performance by being oriented in the binder. As the dichroic dye, an azo dye, stilbene dye, pyrazolone dye, triphenylmethane dye, quinoline dye, oxazine dye, thiazine dye or anthraquinone dye is used. The dichroic dye is preferably water-soluble. The dichroic dye preferably has a hydrophilic substituent (for example, sulfo, amino, hydroxyl). For example, the compound described in page 58 of the Society of Invention Disclosure Technique (public technical number 2001-1745, issue date March 15, 2001, Society of Invention).

  The detailed polarizing plate production method and polarizing plate characteristics are described in paragraphs [0008] to [0020] of JP-A-2005-128520, paragraphs [0007] to [0013] of JP-A-2005-266222, Paragraph Nos. [0083] to [0113] of JP-A-2005-138375, paragraph numbers [0138] to [0145] of JP-A-2006-2026, paragraph numbers [0105] to [0105] of JP-A-2006-45500. [0111] can be preferably used.

(2) Application of optical compensation layer (creation of optical compensation sheet)
The optically anisotropic layer is for compensating the liquid crystal compound in the liquid crystal cell in the black display of the liquid crystal display device, and forms an alignment film on the cycloolefin resin film, and further provides an optically anisotropic layer. It is formed by doing. As specific production methods, for example, those described in paragraph numbers [0147] to [0184] of JP-A-2006-2026 and paragraph numbers [0114] to [0147] of JP-A-2006-45500 are preferable. Can be used.

(3) Application of antireflection layer (antireflection film)
The antireflection film generally has a low refractive index layer which is also an antifouling layer, and at least one layer having a higher refractive index than that of the low refractive index layer (ie, a high refractive index layer and a medium refractive index layer) on a transparent substrate. It is provided. Colloidal metal by multilayer deposition of transparent thin films of inorganic compounds (metal oxides, etc.) with different refractive indexes by chemical vapor deposition (CVD), physical vapor deposition (PVD), and sol-gel methods of metal compounds such as metal alkoxides A method of forming a thin film by post-processing after forming an oxide particle film is mentioned. The ultraviolet irradiation is described in JP-A-9-157855, and the plasma treatment is described in JP-A-2002-327310. On the other hand, various antireflection films formed by laminating thin films in which inorganic particles are dispersed in a matrix have been proposed as antireflection films with high productivity. The antireflection film which consists of the antireflection film which provided the anti-glare property in which the surface of the uppermost layer has the shape of a fine unevenness to the antireflection film by application | coating as mentioned above is also mentioned.
For the purpose of improving the visibility of flat panel displays such as LCD, PDP, CRT, EL, etc., any or all of a hard coat layer, an antiglare layer and an antireflection layer are provided on one or both sides of the cycloolefin film of the present invention. can do. Desirable embodiments as such a hard coat layer, an antiglare layer, and an antireflection layer are disclosed in JIII Journal of Technical Disclosure (Publication No. 2001-1745, published on March 15, 2001, Invention Association), pages 54-57. Page, paragraph numbers [0137] to [0167] of JP-A-2005-178194, paragraph numbers [0136] to [0154] of JP-A-2005-325258, paragraph number [0191] to JP-A-2006-2026 [0224], paragraph numbers [0156] to [0175] of JP-A-2006-45500, and paragraph numbers [0095] to [0103] of JP-A-2006-45501. These manufacturing methods can be preferably used.

<Liquid crystal display device>
The cycloolefin resin film of the present invention, and the polarizing plate, optical compensation film, and antireflection film of the present invention using the cycloolefin resin film of the present invention can be used for liquid crystal display devices in various display modes. Each liquid crystal mode in which these films are used will be described below. Among these modes, the cycloolefin resin film, polarizing plate and optical compensation film of the present invention are particularly preferably used for TN, STN, VA, and IPS mode liquid crystal display devices. These liquid crystal display devices may be any of a transmissive type, a reflective type, and a transflective type.

(TN mode liquid crystal display)
It is most frequently used as a color TFT liquid crystal display device and is described in many documents. The alignment state in the liquid crystal cell in the TN mode black display is an alignment state in which the rod-like liquid crystalline molecules rise at the center of the cell and the rod-like liquid crystalline molecules lie in the vicinity of the cell substrate. The cycloolefin resin film of the present invention may be used as a support for a retardation plate of a TN type liquid crystal display device having a TN mode liquid crystal cell. TN mode liquid crystal cells and TN type liquid crystal display devices have been well known for a long time. Regarding the optical compensation sheet used in the TN type liquid crystal display device, each of JP-A-3-9325, JP-A-6-148429, JP-A-8-50206 and JP-A-9-26572, and Mori. It is described in other papers (Jpn. J. Appl. Phys. Vol. 36 (1997) p. 143 and Jpn. J. Appl. Phys. Vol. 36 (1997) p. 1068).

(STN type liquid crystal display device)
The cycloolefin resin film of the present invention may be used as a support for a retardation plate of an STN type liquid crystal display device having an STN mode liquid crystal cell. In general, in a STN type liquid crystal display device, rod-like liquid crystalline molecules in a liquid crystal cell are twisted in the range of 90 to 360 °, and the refractive index anisotropy (Δn) and cell gap (d) of the rod-like liquid crystalline molecules. Product (Δnd) is in the range of 300 to 1500 nm. The optical compensation sheet used in the STN type liquid crystal display device is described in JP-A-2000-105316.

(OCB mode liquid crystal display)
This is a bend alignment mode liquid crystal cell in which rod-like liquid crystal molecules are aligned in a substantially opposite direction (symmetrically) between the upper part and the lower part of the liquid crystal cell. Liquid crystal display devices using a bend alignment mode liquid crystal cell are disclosed in US Pat. Nos. 4,583,825 and 5,410,422. Since the rod-like liquid crystal molecules are symmetrically aligned at the upper and lower portions of the liquid crystal cell, the bend alignment mode liquid crystal cell has a self-optical compensation function. Therefore, this liquid crystal mode is also called an OCB (Optically Compensatory Bend) liquid crystal mode.
Similarly to the TN mode, the liquid crystal cell in the OCB mode is in a black display, and the alignment state in the liquid crystal cell is such that the rod-like liquid crystal molecules rise in the center of the cell and the rod-like liquid crystal molecules lie in the vicinity of the cell substrate. .

(VA mode liquid crystal display device)
The feature is that the rod-like liquid crystalline molecules are oriented substantially vertically when no voltage is applied. In the VA mode liquid crystal cell, (1) the rod-like liquid crystalline molecules are oriented substantially vertically when no voltage is applied. In addition to a narrowly defined VA mode liquid crystal cell (described in JP-A-2-176625) that is aligned substantially horizontally when a voltage is applied, (2) the VA mode is multi-domained to expand the viewing angle ( Liquid crystal cell (in MVA mode) (SID97, Digest of tech. Papers 28 (1997) 845), (3) Rod-like liquid crystal molecules are substantially vertically aligned when no voltage is applied, and twisted A liquid crystal cell in a domain alignment mode (n-ASM mode) (described in the proceedings 58-59 (1998) of the Japanese Liquid Crystal Society) and (4) a SURVAVAL mode liquid crystal cell (LCD interface) Announced at National 98).
The cycloolefin resin film of the present invention may be used as an optical compensator or a support for an optical compensator in a VA liquid crystal display device having a VA mode liquid crystal cell. Or it is used especially advantageously as a protective film of a polarizing plate. The VA-type liquid crystal display device may be an alignment-divided system as described in, for example, JP-A-10-123576.

(IPS mode liquid crystal display)
The feature is that the rod-like liquid crystalline molecules are aligned substantially horizontally in the plane when no voltage is applied, and this is characterized by switching by changing the orientation direction of the liquid crystal with or without voltage application. Specifically, JP-A No. 2004-365941, JP-A No. 2004-12731, JP-A No. 2004-215620, JP-A No. 2002-221726, JP-A No. 2002-55341, JP-A No. 2003-195333 are disclosed. Can be used.
The cycloolefin resin film of the present invention may be used as an optical compensator or a support for an optical compensator in a VA liquid crystal display device having a VA mode liquid crystal cell. Or it is used especially advantageously as a protective film of a polarizing plate. In these modes, the liquid crystal material is aligned substantially in parallel during black display, and black is displayed by aligning liquid crystal molecules in parallel with the substrate surface in the absence of applied voltage. In these embodiments, the polarizing plate using the cycloolefin resin film of the present invention contributes to widening the viewing angle and improving the contrast.

(Reflective liquid crystal display)
The cycloolefin resin film of the present invention is also advantageously used as a retardation plate of a reflective liquid crystal display device of TN type, STN type, HAN type, and GH (Guest-Host) type. These display modes have been well known since ancient times. The TN-type reflective liquid crystal display device is described in JP-A-10-123478, International Publication WO98 / 48320, and Japanese Patent No. 3022477. The optical compensation sheet used in the reflective liquid crystal display device is described in International Publication WO 00/65384 pamphlet. Further, the ECB mode and STN mode liquid crystal display devices can be optically compensated in the same way as described above.

(Other liquid crystal display devices)
The cycloolefin resin film of the present invention is also advantageously used as a support for an optical compensation sheet of an ASM type liquid crystal display device having an ASM (Axially Symmetric Aligned Microcell) mode liquid crystal cell. The ASM mode liquid crystal cell is characterized in that the thickness of the cell is maintained by a position-adjustable resin spacer. Other properties are the same as those of the TN mode liquid crystal cell. The ASM mode liquid crystal cell and the ASM type liquid crystal display device are described in a paper by Kume et al. (Kume et al., SID 98 Digest 1089 (1998)). The ECB mode and STN mode liquid crystal display devices can be optically compensated in the same way as described above.

The evaluation method and measurement method used in the present invention are described below.
(Impact strength)
The impact strength of the melt-formed cycloolefin resin film is the energy measured when the cycloolefin resin film is punched vertically by the rotation of the pendulum. The following equipment and conditions were adopted. In general, a value measured by a film impact tester (impact tester) has a film thickness dependency. Therefore, in the present invention, a value normalized by the film thickness by the following calculation formula is defined as the film impact strength.
Equipment: Made by Toyo Seiki Seisakusho, film impact tester (impact tester)
Condition: Test capacity 30 kgf · cm, head diameter 1 inch Calculation formula: Film impact (kgf · cm / cm) =
(Energy when punching the film) / (film thickness)
SI unit conversion (J / m) = 9.80665 × (kgf · cm / cm)

(Tear strength)
The tear strength of the cycloolefin resin film (sample) after being placed in an environment of 60 ° C. and 90% relative humidity for 500 hours was measured using a light strength tear tester (manufactured by Toyo Seiki Seisakusho). When the sample has a rectangular size with the length of side A of 64 mm and the length of side B of 51 mm, a notch with a depth of 13 mm from the end is made at the center position of side A, and the remaining sample 51 mm is torn The reading was read. As the tear strength, the tear force (g) obtained from the indicated value was normalized by the film thickness as the film tear strength. When measuring the tear strength in the longitudinal direction of the film, the sample is sampled so that the B side of the sample is parallel to the longitudinal direction of the film, and when measuring the tear strength in the width direction of the film, the A side of the sample is Sampling was performed in parallel with the longitudinal direction of the film.
In addition, the measurement of the tear strength of a film longitudinal direction and the width direction was each performed using five samples, and the average value was employ | adopted as a measured value. Since the measured value depends on the film thickness, in the present invention, the value normalized by the film thickness according to the following calculation formula is defined as the film tear strength.
Tear strength (g / mm) = measured value (g) / film thickness (mm)
In this invention, it described using the average value of the tear strength of a film longitudinal direction and the width direction.

(Crack occurrence rate)
The number of corners (n) in which five cycloolefin resin films were superposed (same configuration) were punched with a 10 cm square Thomson blade, and the number of corners (n) in which punching defects such as cracks, cracks, and chips were detected (n) Divided by m), the percentage of defective punching was expressed as a percentage as follows.
Punching defect occurrence rate (%) = 100 × (n / m)

(Failure rate of liquid crystal display devices)
Using a commercially available VA type liquid crystal display device (42 inch type, direct type backlight) or TN type liquid crystal display device (26 inch type, direct type backlight), a backlight side polarizing plate and a viewing side polarizing plate of the liquid crystal cell Peeling, and instead of this, polarizing plates prepared using the cycloolefin resin film of the present invention are bonded to both surfaces of the liquid crystal cell, respectively, and the polarizing direction of the polarizing plate is the cycloolefin resin film. A liquid crystal display device was produced by performing the process so that the surface on which the film is bonded becomes the liquid crystal cell side and the absorption axis in the same direction as the previously bonded polarizing plate. The manufactured liquid crystal display device was subjected to a 200-hour durability test with a direct backlight turned on at 40 ° C. and 90% relative humidity, and then the backlight was turned on at room temperature for 24 hours. When displaying black, the area of the liquid crystal display failure that occurred due to cracks, light leakage, etc. was observed, and the failure occurrence rate was determined by the ratio of the failure occurrence area to the liquid crystal panel area.

(Measurement of Tg)
20 mg of a sample was placed in a DSC measurement pan. This was heated to 30 ° C. to 250 ° C. at 10 ° C./min in a nitrogen stream and then cooled to 30 ° C. at −10 ° C./min. Thereafter, the temperature was raised again to 30 ° C. to 250 ° C., and the temperature at which the baseline began to deviate from the low temperature side was defined as Tg.

(Re and Rth)
The film was conditioned at 25 ° C. and 60% relative humidity for 24 hours, then using a prism coupler (MODEL2010 Prism Coupler: manufactured by Metricon), and at 25 ° C. and 60% relative humidity, using a 532 nm solid laser, the following formula (a The average refractive index (n) represented by
Formula (a): n = (n _TE × 2 + n _TM ) / 3
[ _Where n _TE is a refractive index measured with polarized light in the film plane direction, and n _TM is a refractive index measured with polarized light in the film surface normal direction. ]
Re (λ) and Rth (λ) represent in-plane retardation and retardation in the thickness direction at the wavelength λ, respectively. Re (λ) was measured by making light having a wavelength of λ nm incident in the normal direction of the film in KOBRA 21ADH or WR (manufactured by Oji Scientific Instruments).
When the film to be measured was represented by a uniaxial or biaxial refractive index ellipsoid, Rth (λ) was calculated by the following method.
Rth (λ) is Re (λ), with the in-plane slow axis (determined by KOBRA 21ADH or WR) as the tilt axis (rotation axis) (in the absence of the slow axis, any in-plane value) Measurements were made at 11 points in total by making light of wavelength λ nm incident from each inclined direction in steps of 10 ° from −50 ° to + 50 ° from the normal direction to the normal direction of the film). Then, KOBRA 21ADH or WR was calculated based on the measured retardation value, average refractive index, and input film thickness value.
In the above, there is no particular description regarding λ, and when only Re and Rth are described, it represents a value measured using light with a wavelength of 590 nm. In addition, in the case of a film having a retardation value of zero at a certain tilt angle with the in-plane slow axis from the normal direction as the rotation axis, the retardation value at a tilt angle larger than that tilt angle. After changing its sign to negative, KOBRA 21ADH or WR calculates.
In addition, the retardation value is measured from the two inclined directions, with the slow axis as the tilt axis (rotation axis) (when there is no slow axis, the arbitrary direction in the film plane is the rotation axis), Based on the value, the average refractive index, and the input film thickness value, Rth can also be calculated from the following formulas (b) and (c).

［式中、Ｒｅ（θ）は法線方向から角度θ傾斜した方向におけるレタ−デーション値を表す。また、ｎｘは面内における遅相軸方向の屈折率を表し、ｎｙは面内においてｎｘに直交する方向の屈折率を表し、ｎｚはｎｘおよびｎｙに直交する方向の屈折率を表す。］

[In the formula, Re (θ) represents a retardation value in a direction inclined by an angle θ from the normal direction. Further, nx represents the refractive index in the slow axis direction in the plane, ny represents the refractive index in the direction perpendicular to nx in the plane, and nz represents the refractive index in the direction perpendicular to nx and ny. ]

Formula (c): Rth = ((nx + ny) / 2−nz) × d
In the case where the film to be measured cannot be expressed by a uniaxial or biaxial refractive index ellipsoid, that is, a film having no so-called optical axis, Rth (λ) was calculated by the following method.
Rth (λ) is from −50 degrees to +50 degrees with respect to the normal direction of the film, with Re (λ) being the in-plane slow axis (determined by KOBRA 21ADH or WR) and the tilt axis (rotation axis). Measured at 11 points by making light of wavelength λ nm incident from each inclined direction in 10 degree steps, and KOBRA 21ADH or WR is calculated based on the measured retardation value, average refractive index, and input film thickness value. did.
By inputting these average refractive index and film thickness, KOBRA 21ADH or WR was allowed to calculate nx, ny, and nz. From this calculated nx, ny, and nz, Nz = (nx−nz) / (nx−ny) was further calculated.

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

(1) Cycloolefin resin (1-1) Cycloolefin resin-A (ring-opening polymer)
6-methyl-1,4,5,8-dimethano-1,4,4a, 5,6,7,8,8a-octahydronaphthalene, 10 parts of a 15% cyclohexane solution of triethylaluminum as a polymerization catalyst, triethylamine 5 And 10 parts of a 20% cyclohexane solution of titanium tetrachloride were added to perform ring-opening polymerization in cyclohexane, and the resulting ring-opening polymer was hydrogenated with a nickel catalyst to obtain a polymer solution. This polymer solution was coagulated in isopropyl alcohol and dried to obtain a powdery resin. The number average molecular weight of this resin was 40,000, the hydrogenation rate was 99.8% or more, and the Tg was 139 ° C.

(1-2) Cycloolefin resin-B (ring-opening polymer)
100 parts by mass of 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.12.5, 17.10] -3-dodecene (specific monomer B) and 5- (4-biphenylcarbonyloxy) In a reaction vessel in which 150 parts by mass of bicyclo [2.2.1] hept-2-ene (specific monomer A), 18 parts by mass of 1-hexene (molecular weight regulator) and 750 parts by mass of toluene were substituted with nitrogen. Charge and heat the solution to 60 ° C. Next, 0.62 parts by mass of a toluene solution of triethylaluminum (1.5 mol / l) as a polymerization catalyst and tungsten hexachloride modified with tert-butanol and methanol (tert-butanol: methanol: By adding 3.7 parts by mass of a toluene solution (concentration 0.05 mol / l) of tungsten = 0.35 mol: 0.3 mol: 1 mol), the system is heated and stirred at 80 ° C. for 3 hours. A ring-opening polymer solution was obtained by a ring-opening polymerization reaction. The polymerization conversion rate in this polymerization reaction was 97%, and the intrinsic ring viscosity (ηinh) of the obtained ring-opened polymer measured in chloroform at 30 ° C. was 0.65 dl / g.

The autoclave was charged with 4,000 parts by mass of the ring-opening polymer solution thus obtained, and 0.48 part of RuHCl (CO) [P (C ₆ H ₅ ) ₃ ] ₃ was added to the ring-opening polymer solution. The hydrogenation reaction was performed by heating and stirring for 3 hours under the conditions of hydrogen gas pressure of 100 kg / cm ² and reaction temperature of 165 ° C. After cooling the obtained reaction solution (hydrogenated polymer solution), the hydrogen gas was released. This reaction solution was poured into a large amount of methanol to separate and recover a coagulated product, which was dried to obtain a hydrogenated polymer (cyclic polyolefin resin). The hydrogenated polymer thus obtained was measured for hydrogenation rate of olefinically unsaturated bonds using 400 MHz, ¹ H-NMR, and found to be 99.9%. When the number average molecular weight (Mn) and weight average molecular weight (Mw) in terms of polystyrene were measured by gel permeation chromatography (GPC method, solvent: tetrahydrofuran), the number average molecular weight (Mn) was 39,000, and the weight average molecular weight ( Mw) was 126,000, and the molecular weight distribution (Mw / Mn) was 3.23. Moreover, Tg was 110 degreeC.

(1-3) Cycloolefin resin-C (addition polymer)
The cycloolefin compound described in Example 2 of JP-A-2005-330465 (Tg = 127 ° C.)
(1-4) Cycloolefin resin-D (addition polymer)
The cycloolefin compound described in Example 1 of JP-T-8-507800 (Tg = 181 ° C.)
(1-5) Cycloolefin resin-E (addition polymer)
APL6015T (Tg = 145 ° C) manufactured by Mitsui Chemicals, Inc.
(Vi) Cycloolefin resin-F (addition polymer)
TOPAS6013 (Tg = 130 ° C) manufactured by Polyplastics Co., Ltd.
(Vii) Saturated norvol resin-G
Saturated norbornene compound (Tg 140 ° C.) described in Example 1 of Japanese Patent No. 3693803.

(2) Film formation To 100 parts by mass of the above cycloolefin resins -A to G, 1.3 parts by mass of Adeka Stub AO-60 (manufactured by Asahi Denka Kogyo Co., Ltd.) as a stabilizer and Adekastab LA- as an ultraviolet absorber 31 (manufactured by Asahi Denka Kogyo Co., Ltd.) and 1.1 parts by mass were added to form cylindrical pellets having an average diameter of 3 mm and an average length of 5 mm. This was dried with a vacuum dryer at 110 ° C., the water content was adjusted to 0.05% or less, and then charged into a hopper adjusted to Tg−10 ° C.
The mixture was melted at 260 ° C. with a kneading extruder. The melt sent from the gear pump was adjusted to the shear rate shown in Table 1, filtered through a leaf disk filter having a filtration accuracy of 5 μm, and passed through a static mixer to satisfy the die discharge conditions shown in Table 1. A melt (melted resin) was extruded from a hanger coat die onto a cast roll (CR). Then, it casted on the cast roll set to the glass transition temperature Tg, and the touch roll was made to contact this, and it was set as the touch roll pressing pressure of Table 1. The touch roll was the one described in Example 1 of JP-A-11-235747 (the one described as a double holding roll), and the temperature was adjusted to Tg-5 ° C. (however, the thickness of the thin metal outer cylinder) Was 3 mm).
Moreover, the electrostatic application method performed the electrostatic application to the both ends of the discharged melt resin on the electrostatic application conditions of Table 1 instead of using a touch roll. After this, after passing through a cast roll whose temperature was set to Tg + 5 ° C. and Tg−10 ° C., trimming both ends (5% of the total width), and then processing the thickness 10 mm wide and 50 μm high at both ends After applying (knurling) and laminating with a protective film having a thickness of 20 μm, an unstretched film having a width of 2.0 m and a length of 3000 m was obtained. Each of the obtained films was measured and evaluated for the physical properties of the film by the above-described evaluation method and listed in Table 1.

表１の結果から明らかなように、本発明の製造条件に従って、作成した本発明１〜本発明１５のフィルムは、衝撃強度および引裂け強度が強く、フィルムを打ち抜きする際に、クラックなどの不良発生率が低く、優れたシクロオレフィン樹脂フィルムであった。

As is clear from the results in Table 1, the films of Inventions 1 to 15 prepared according to the production conditions of the invention have high impact strength and tear strength, and defects such as cracks when punching the film. The generation rate was low, and it was an excellent cycloolefin resin film.

(3) Stretching and relaxation The cycloolefin resin film obtained by the melt film formation was stretched and thermally relaxed under the conditions shown in Table 2. Although not described in the table, the unstretched film of the present invention described in Table 1 other than that described in Table 2 was stretched in the same manner, and similarly good results were obtained.

(4) Production of polarizing plate In any level, the surface of the film was subjected to corona treatment so that the contact angle with water on the surface was 60 °.
According to Example 1 of Japanese Patent Laid-Open No. 2001-141926, a circumferential speed difference was given between two pairs of nip rolls and stretched in the longitudinal direction to prepare a polarizing layer having a thickness of 20 μm.
These were bonded to each other using a PVA (PVA-117H manufactured by Kuraray Co., Ltd.) 3% aqueous solution so as to have the following constitution to produce a polarizing plate.
Polarizing plate A: Unstretched cycloolefin resin film / polarizing layer / Fujitack Polarizing plate B: Stretched cycloolefin resin film / polarizing layer / Fujitac The polarizing plate thus obtained is commercially available. The VA type liquid crystal display device was evaluated. Using a commercially available VA type liquid crystal display device (42 inch type, direct type backlight) or TN type liquid crystal display device (26 inch type, direct type backlight), the backlight side polarizing plate and the viewing side polarizing plate of the liquid crystal cell The prepared polarizing plate A or polarizing plate B using the obtained cycloolefin resin film is bonded to both surfaces of the liquid crystal cell, respectively, and the polarizing direction of the polarizing plate is the above prepared cycloolefin resin. A liquid crystal display device was manufactured by making the surface on which the film was bonded to the liquid crystal cell side and so that the absorption axis was in the same direction as the polarizing plate bonded in advance. When using the polarizing plate B, the retardation film attached to the VA liquid crystal display device is peeled off and then bonded. Thus, the produced liquid crystal display device was evaluated as follows.

(Visibility)
The liquid crystal display device produced above was subjected to a durability test for 1000 hours by lighting a direct type backlight in an environment of 60 ° C. and 90% relative humidity, and then after 24 hours of lighting the backlight at room temperature. The screen was displayed in black and visually observed. When the polarizing plate using the present invention 1-15 unstretched film and the cycloolefin resin film of stretch-1 to stretch-7 of the present invention is used in a liquid crystal display device, the black color appears to be sharp and clear. Unevenness was not observed, and the optical properties were excellent. On the other hand, when the film of Comparative Example 1 and Comparative Example 2 is used for the polarizing plate and the liquid crystal cell, there are no black spots due to light leakage of cracks in the square part, and the sharpness is low and the color unevenness is clearly observed. It was.

(Viewing angle fluctuation)
The viewing angle measurement of the liquid crystal display device produced using ELZIM company make and EZ-Contrast160D was performed in the environment of 25 degreeC60% relative humidity. Subsequently, the viewing angle was measured in an environment of 25 ° C. and 10% relative humidity, and further at 25 ° C. and 80% relative humidity, and evaluated according to the following criteria. Finally, viewing angle measurement was performed once again in an environment of 25 ° C. and 60% relative humidity, and it was confirmed that the change during the measurement was a reversible fluctuation. These measurements were performed after the liquid crystal display device was placed in the environment for 12 hours. When tackling polarizing plates and liquid crystal display devices using the unstretched films of the present invention 1 to 25 and the cycloolefin resin films of the stretched -1 to stretched -7 of the present invention, there are no viewing angle fluctuations and excellent optics. It was a characteristic.

(Color shift)
The produced liquid crystal display device was displayed in white, and a change in hue of 60 ° was measured by the following method.
The measurement of the change in hue 60 ° is made using a Topcon Co., Ltd. color luminance meter BM-5A and a self-made turntable. In the self-made liquid crystal cell, a three-color light source (Hakuba Light Viewer 7000PRO) was used, and a change in hue of 60 ° was measured with reference to the color of the light source.
As the maximum color change, when the absolute value of the change amount in each coordinate axis of the xy coordinates was Δx and Δy, respectively, the evaluation was performed according to the following criteria. In the case where a polarizing plate using the unstretched film of the present invention 1-15 and the cycloolefin resin film of stretch-1 to stretch-7 of the present invention is used in a liquid crystal display device, Δx <0.02 and Δy <0.01. And excellent optical characteristics. On the other hand, it was found that Δx> 0.2 or Δy> 0.2 when the film was taken into a polarizing plate or a liquid crystal cell using the films of Comparative Examples 1 and 2, and the color shift was unstable.

(5) Production of optical compensation film The cycloolefin resin film of the present invention was used in place of the cellulose acetate film coated with the liquid crystal layer of Example 1 of JP-A-11-316378. Those implementing the present invention showed good performance. Among them, the addition polymerization type cycloolefin resin film was good.

  In Example 1 of JP-A-7-333433, in place of the cellulose acetate film, the cycloolefin resin film of the present invention is employed, and an optical compensation filter film can be similarly produced. It was. Among them, the addition polymerization type cycloolefin resin film was good.

(6) Production of low-reflection film A low-reflection film was produced from the cycloolefin resin film of the present invention in accordance with Example 47 of the Japan Institute of Invention and Technology (Publication No. 2001-1745), and good optical performance was obtained. . In particular, the addition polymerization type cycloolefin resin film was good.

(7) Production of Liquid Crystal Display Element The polarizing plate of the present invention is a liquid crystal display device described in Example 1 of JP-A-10-48420, and a discotic described in Example 1 of JP-A-9-26572. An optically anisotropic layer containing liquid crystal molecules, an alignment film coated with polyvinyl alcohol, a 50-inch VA liquid crystal display device manufactured according to FIGS. 2 to 9 of JP-A-2000-154261, JP-A-2000- The 50-inch OCB type liquid crystal display device manufactured according to FIGS. 10 to 15 of Japanese Patent No. 154261 and the IPS type liquid crystal display device shown in FIG. 11 of Japanese Patent Application Laid-Open No. 2004-12731 were used. Furthermore, when the low reflection film of this invention was stuck and evaluated on the outermost layer of these liquid crystal display devices, the favorable liquid crystal display element was obtained. In particular, the addition polymerization type cycloolefin resin film was good.

FIG. 1 is a schematic diagram showing a cross-sectional view of a die. FIG. 2 is a schematic diagram showing the neck-in amount. The schematic block diagram of the film manufacturing apparatus which manufactures the cycloolefin resin film in the case of performing long span extending | stretching is shown. The perspective explanatory view of the longitudinal extension part of Drawing 3 is shown. The schematic block diagram of the film manufacturing apparatus which manufactures the cycloolefin resin film in the case of performing short span stretching is shown. The perspective explanatory view of the longitudinal extension part of Drawing 4 is shown. It is explanatory drawing of the bowing generate | occur | produced with the manufacturing method which does not heat-set. It is explanatory drawing which shows suppression of generation | occurrence | production of the bowing by heat setting.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 10a Film manufacturing apparatus 12 Dryer 14 Extruder 16 Gear pump 18 Filter 20 Die 22 Cooling part 24 Touch roll 26 Touch roll 28 Cast drum 30, 30a Longitudinal stretch part 32 Inlet side nip roll 33 Preheating roll 34 Outlet side nip roller 35 Preheating roll 36 Preheating part 37 Nip roll 39 Nip roll 42 Transverse stretching part 44 Heat fixing part 46 Winding part Fa Unstretched film Fb Longitudinal stretched film F Cycloolefin resin film Lb Boeing curve

Claims (16)

  A cycloolefin resin film having an impact strength of 1000 J / m to 30000 J / m.   2. The cycloolefin resin film according to claim 1, having a tear strength of 50 g / mm to 1000 g / mm after 500 hours at 60 ° C. and 90% relative humidity.   Thickness is 30 micrometers-250 micrometers, The cycloolefin resin film of Claim 1 or 2 characterized by the above-mentioned.   The method for producing a cycloolefin resin film according to any one of claims 1 to 3, wherein the cycloolefin resin film is produced by a melt film-forming method. The method for producing a cycloolefin resin film according to claim 4, wherein a shear rate between the gear pump and the die is set to 5 to 50 sec ⁻¹ .   6. The cycloolefin resin according to claim 4, wherein a ratio (X / Y) between the die tip clearance X and the maximum gap Y of the die cross-section melt part flow path is 0.01 to 0.5. A method for producing a film.  The method for producing a cycloolefin resin film according to any one of claims 4 to 6, wherein the neck-in amount of the melt discharged from the die is 90% to 99%.  The method for producing a cycloolefin resin film according to any one of claims 4 to 7, wherein the cycloolefin resin film is formed by a touch roll method with a pressing pressure of a touch roll of 0.1 MPa to 10 MPa.  The method for producing a cycloolefin resin film according to any one of claims 4 to 7, wherein the film is formed by an electrostatic application method at an electrostatic voltage of 5 KV to 50 KV.  The method for producing a cycloolefin resin film according to any one of claims 4 to 9, wherein a film forming speed on the most upstream cast roll is 20 m / min to 70 m / min.   A cycloolefin resin film obtained by stretching the film according to any one of claims 1 to 3 by 1.01 to 3.0 times in at least one direction.   The cycloolefin resin film according to claim 1, wherein the cycloolefin is an addition-polymerized cycloolefin.   The polarizing plate which laminated | stacked at least 1 layer of the cycloolefin resin film of any one of Claims 1-3, 11 and 12.   The optical compensation film using the cycloolefin resin film of any one of Claims 1-3, 11, and 12.   The antireflection film using the cycloolefin resin film of any one of Claims 1-3, 11, and 12.   The cycloolefin resin film according to any one of claims 1 to 3, 11 and 12, the polarizing plate according to claim 13, the optical compensation film according to claim 14, and the antireflection film according to claim 15. A liquid crystal display device using at least one of the above.

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