JP2006299110A - Method for producing cyclic olefin polymer film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing optical films having excellent optical isotropy usable for phase contrast films and the like by T-die melt extrusion method at a high productivity. <P>SOLUTION: The method for producing optical films comprises extruding a specific cyclic olefin polymer by T-die melt extrusion method as fused films and cooling the fused films with one or multiple cooling rollers, wherein the films are withdrawn at 10-100 m/min withdrawing rate. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for producing an optical film having excellent surface smoothness and thickness accuracy made of a cyclic olefin polymer.

  In recent years, flat panel displays typified by liquid crystal displays, organic ELs, PDPs, etc. have features that are thin and lightweight to meet market needs, and are rapidly spreading or expanding their use range. In these flat panel displays, a number of optical films are used. For example, a polarizer protective film, a retardation film, a viewing angle compensation film, a transparent electrode film, a light diffusion film, a light reflection film, an electromagnetic wave shielding film, a display Used for surface protection film. In general, these optical films are required to have very high transparency, excellent surface smoothness, and thickness accuracy so as not to deteriorate the visibility of the display. Examples of optical films used in flat panel displays include polyethylene terephthalate film, polycarbonate film, polyether sulfone film, cyclic polyolefin film, linear polyolefin film, polymethyl methacrylate film, triacetyl cellulose film, and thermosetting resin. A film etc. can be mentioned as a representative example.

  As a method for producing these optical films, a solution casting method has been proposed (see, for example, Patent Document 1). In the solution casting method, a high-viscosity solution (dope) is cast on a support substrate, and then heated to remove most of the solvent, peel off from the support substrate as a self-supporting film, and further heat-dried. This is a film formation method that removes the remaining solvent, and since no tension is applied to the film, an optical film with excellent optical isotropy can be obtained, but it is extremely accompanied by solvent drying equipment and solvent recovery equipment. Since a large-scale and expensive manufacturing facility is required and the time required for drying the solvent is long, there is a problem that productivity is poor and film cost is high. In order to improve productivity by the solution casting method, means for extending the solvent drying process and means for shortening the solvent drying time can be considered. When the drying time of the solvent is shortened, the solvent tends to remain in the formed film, and there is a concern about the influence on the environment.

  Also, a melt extrusion method using a T die (hereinafter referred to as a T die melt extrusion method) melts a resin in an extruder and extrudes the molten resin into a film form from a slit of the T die, and then rolls or air It is a molding method that is pulled down while cooling, etc. Compared with the solution casting method, the manufacturing equipment is cheaper and the productivity is excellent, but because tension is applied when the film is pulled, it is an optically isotropic optical film In order to achieve this, there is a problem that the take-off speed must be very slow, and high productivity cannot be obtained.

JP 2004-189828 A

  However, the optical film obtained by the production method described in Patent Document 1 has characteristics such as excellent transparency, heat resistance, surface hardness, etc., but solvent drying equipment and solvent recovery which are problems of the solution casting method In terms of facilities, etc., it has not been resolved.

  Furthermore, the T-die melt extrusion method is used to produce an optical film having excellent optical isotropy, although it is widely known as a method capable of producing a film with high surface smoothness with high productivity. Therefore, it is necessary to reduce the take-up speed, which is inferior in economic efficiency.

  Therefore, an object of the present invention is to provide a method of producing by an T-die melt extrusion method that is excellent in economic efficiency of an optical film made of a cyclic olefin polymer excellent in surface smoothness and thickness accuracy.

  As a result of intensive studies in view of the above problems, the present inventors have taken a specific cyclic olefin polymer at a specific take-off speed by a T-die melt extrusion method, which is advantageous in cost to the solution casting method. The inventors have found that an optical film excellent in surface smoothness and thickness accuracy can be obtained with high production efficiency, and have completed the present invention.

  That is, the present invention provides the following general formula (1)

（ここで、Ｘ及びＹは独立にメチレン基、酸素原子、硫黄原子又はテルル原子を表わし、ｎは０または正の整数を表わす。）
で表わされる繰り返し単位からなる環状オレフィン重合体をＴダイ溶融押出法により溶融フィルムとして押し出し、該溶融フィルムを一個又は複数個の冷却ロールにて冷却しフィルムを製造する際に、引き取り速度１０〜１００ｍ／分の範囲で引き取ることを特徴とする光学フィルムの製造方法に関するものである。

(Here, X and Y independently represent a methylene group, an oxygen atom, a sulfur atom or a tellurium atom, and n represents 0 or a positive integer.)
When a cyclic olefin polymer composed of repeating units represented by the following formula is extruded as a molten film by a T-die melt extrusion method and the molten film is cooled by one or a plurality of cooling rolls, a take-up speed of 10 to 100 m is obtained. It is related with the manufacturing method of the optical film characterized by taking out in the range of / min.

  Hereinafter, the present invention will be described in detail.

  The cyclic olefin polymer used in the present invention is a polymer represented by the general formula (1), and X and Y in the general formula (1) independently represent a methylene group, an oxygen atom, a sulfur atom or a tellurium atom, n represents 0 or a positive integer.

  As a method for producing the cyclic olefin polymer represented by the general formula (1), any method can be used as long as the cyclic olefin polymer represented by the general formula (1) is obtained. Since the cyclic olefin polymer represented by 1) is obtained, a hydrogenated polymer is obtained by polymerizing a polymerizable monomer produced by a Diels-Alder reaction of vinyl ethers and alicyclic dienes to obtain an unhydrogenated polymer. It is preferable to use the method to do.

  Examples of the vinyl ether used to obtain the polymerizable monomer include tricyclodecane vinyl ether, and examples of the alicyclic diene include cyclopentadiene and dicyclopentadiene.

  The charged molar ratio of the alicyclic diene to the vinyl ether in the Diels-Alder reaction between the vinyl ether and the alicyclic diene is preferably from 0.6 to 15, particularly preferably from 1.5 to 10. The reaction can be carried out without solvent or in a solvent inert to the reaction. Examples of the solvent include alkanes such as pentane, octane and nonane; cycloalkanes such as cyclohexane, cycloheptane and cyclooctane; benzene And aromatic hydrocarbons such as toluene, xylene, halogenated alkanes, halogenated aromatic hydrocarbons, carboxylic acid esters, cyclic ethers, and dialkyl ethers. Moreover, 50-300 degreeC of reaction temperature is preferable, Especially preferably, it is 100-250 degreeC, More preferably, it is 180-240 degreeC. There is no limitation on the reaction method, and either batch reaction or continuous reaction can be used. Among them, continuous reaction is preferable from the viewpoint of economy.

  There is no restriction | limiting in particular as a method of superposing | polymerizing the polymerizable monomer manufactured by Diels Alder reaction at the time of manufacturing the cyclic olefin polymer used by this invention, Among these, metathesis ring-opening polymerization is preferable. At that time, it is preferable to use a metathesis ring-opening polymerization catalyst because the polymerization can be efficiently performed. As the metathesis ring-opening polymerization catalyst, a known one can be used, for example, ruthenium, palladium, and the like. , Rhodium, iridium, platinum, tungsten, molybdenum, rhenium compound at least one metal compound (I) and periodic table group 1, group 2, group 3, group 4 metal compound (II) are used in combination be able to.

Specific examples of tungsten, molybdenum, and rhenium compounds include halides, oxyhalides, alkoxy halides, carboxylates, acetylacetonate coordination products, acetylacetonate coordination products of oxides, acetonitrile coordination products, Examples include hydride complexes and the like. Among them, halides, oxyhalides, and the like are preferable because high polymerization activity can be imparted. Particularly, WCl ₆ , WOCl ₄ , MoCl ₅ , MoOCl ₃ , ReCl ₃ , WCl ₂ (OC ₆ H ₅ ). ₄ , MoO ₂ (acac) ₂ and W (OCOR) ₅ are preferable, and WCl ₆ and MoCl ₅ are more preferable.

  Specific examples of the metal compounds of Group 1, Group 2, Group 3, and Group 4 of the periodic table include, for example, n-butyllithium, diethyl zinc, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, diethylaluminum hydride, and trimethylgallium. , Trimethyltin, n-butyltin and the like are exemplified, and diethylaluminum chloride, tetramethyltin and tetraphenyltin are particularly preferable.

  The ratio of the metal compound (I) to the metal compound (II) is preferably 1/1 to 1/30, particularly preferably 1/2 to 1/20 as the molar ratio of metal atoms. Further, alcohols, aldehydes, ketones, amines and the like may be added as activity improvers.

  In the metathesis ring-opening polymerization, a molecular weight regulator can be used. As the molecular weight regulator, for example, α-olefins such as ethylene, 1-hexene, 1-heptene are preferably used. More than one type can be used in combination. The amount of the molecular weight regulator used can be appropriately selected depending on the polymerization temperature, the type of polymerization catalyst, and the amount of the polymerization catalyst. Among them, 0.001 to 0.5 mol is preferable per 1 mol of the charged monomer, and particularly 0.002 To 0.4 mol is preferred.

  Examples of the solvent used in the metathesis ring-opening polymerization include alkanes such as pentane, octane and nonane; cycloalkanes such as cyclohexane, cycloheptane and cyclooctane; aromatic hydrocarbons such as benzene, toluene and xylene; Examples include alkanes; halogenated aromatic hydrocarbons; carboxylic acid esters; cyclic ethers; dialkyl ethers and the like.

In the metathesis ring-opening polymerization, it is possible to copolymerize using other monomers. Examples of the other monomers include 1-hexene, cyclobutene, cyclopentene, cyclooctene, 1,5-cycloocta Diene, 1,5,9-cyclododecatriene, bicyclo [2.2.1] -2-heptene, tricyclo [5.2.1.0 ^2,6 ] -3-decene, tricyclo [5.2.1 .0 ^2,6] -8-decene, tricyclo ^[6.2.1.0 l, 8]-9-undecene, tricyclo ^[6.2.1.0 l, 8]-4-undecene, tetracyclo [4 .4.0.1 ^2,5 . 1 ^7,10 ] -3-dodecene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] -4-pentadecene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] -11-pentadecene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,14 ] -4-hexadecene, pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13] - pentadeca-4,11-diene and the like are exemplified, among which 1-hexene, cyclobutene, cyclopentene, cyclooctene and the like are preferred, especially 1-hexene are preferred.

  There is no restriction | limiting in particular as hydrogenation of the unhydrogenated polymer at the time of obtaining the cyclic olefin polymer used by this invention, Among these, the cyclic olefin polymer represented by General formula (1) is obtained with sufficient reaction efficiency. Therefore, it is preferable to use a hydrogenation catalyst, and as the hydrogenation catalyst, a conventional hydrogenation catalyst of an olefinic compound can be used. For example, palladium, platinum, nickel, rhodium, ruthenium, etc. are carbon, silica, Supported catalysts supported on alumina and titania; nickel naphthenate, nickel acetylacetonate, cobalt octenoate, titanocene dichloride, rhodium acetate, chlorotris (triphenylphosphine) rhodium, dichlorotris (triphenylphosphine) ruthenium, chlorohydro Carbonyl tris (triphenylphosphine Ruthenium, dichloro (triphenylphosphine) ruthenium, homogeneous catalyst such as ruthenium hydride triphenylphosphine is exemplified. In order to promote hydrogenation, it is preferable to use a cocatalyst together with the catalyst. Examples of the cocatalyst include alkylaluminums such as triethylaluminum and alkyllithiums such as n-butyllithium. .

  The form of the hydrogenation catalyst to be used is not particularly limited, and it can be used without any problem in the form of powder or particles. The amount of hydrogenation catalyst used is preferably 0.5 to 2 ppm by weight with respect to the hydrogenation catalyst. The hydrogenation rate is usually 60% or more, preferably 90% or more, more preferably 98% or more.

  The reaction pressure at the time of hydrogenation is preferably normal pressure to 300 atm, particularly preferably 3 to 200 atm. As reaction temperature, 0-200 degreeC is preferable, Most preferably, it is 20-180 degreeC.

The hydrogenation solvent is not particularly limited, and any solvent may be used as long as it is not hydrogenated under the above-mentioned hydrogenation reaction conditions. From the viewpoint of economy and workability, it is preferably common to metathesis ring-opening polymerization. It is preferable to use one.

  The method for producing an optical film of the present invention relates to a method for producing an optical film having excellent optical isotropy. The cyclic olefin polymer is extruded as a molten film by a T-die melt extrusion method, and one or a plurality of the molten films are produced. The present invention relates to a method for producing an optical film, wherein the film is taken up at a take-off speed of 10 to 100 m / min when being cooled with a single cooling roll, and used for producing the optical film of the present invention. An example of a film production apparatus that can be used is shown in FIG. 1 and the present invention will be described. However, the present invention is not limited to this production apparatus, and other apparatus may be added.

  Here, the symbols in FIG. 1 are as follows: 1: twin screw extruder, 2: vacuum vent, 3: diverter valve, 4: gear pump, 5: screen changer, 6: T die, 7: first cooling Each of rolls and 8: take-up film is shown.

  The T-die melt extrusion method referred to in the present invention is a film production method characterized in that after melt-kneading in an extruder, it is extruded from a T-die into a film shape, and the molten film is taken off while being cooled with a cooling roll. . Here, in the T-die melt extrusion method, when a melted film is drawn, tension is applied to the film, and the resulting film generally tends to cause birefringence due to molecular orientation. Therefore, when producing an optical film having excellent optical isotropy, it is necessary to pull the film at a low speed of, for example, less than 10 m / min so as not to apply tension to the film as much as possible and to prevent birefringence due to molecular orientation. there were. In other words, the T-die melt extrusion method is widely known as a method that can produce a film with high surface smoothness with high productivity, but in order to produce an optical film excellent in optical isotropy. The fact is that the features are not fully utilized.

  On the other hand, the method for producing an optical film of the present invention is an optical film at a high speed of 10 to 100 m / min, preferably 10 to 80 m / min, more preferably 10 to 50 m / min by a T-die melt extrusion method. And an optical film having excellent optical isotropy can be produced with high productivity. The film take-up speed is not particularly limited as long as it is in the above range, and the thickness accuracy tends to decrease due to an increase in the take-up speed. Good.

  In addition, in the T-die melt extrusion method, as the molding conditions that affect the film characteristics in addition to the take-up speed, the temperature at the time of melting, the surface temperature of the cooling roll, and in particular, the T-die when there are a plurality of cooling rolls The surface temperature of the 1st cooling roll in the most upstream position of the side is mentioned. And in the manufacturing method of this invention, the temperature at the time of melting should just be suitably selected according to discharge amount, thickness, etc. Among them, in order to avoid the deterioration of the film appearance by thermal decomposition, it is T-die after melting. Is preferably maintained at 300 ° C. or less, and particularly preferably 290 ° C. or less.

  The surface temperature of the chill roll, particularly the setting of the surface temperature of the first chill roll, is one of the important manufacturing conditions that have a great influence on the appearance and optical properties of the obtained optical film. It is optimized in consideration of the balance between property and releasability. In the production method of the present invention, the surface of the cooling roll is obtained so that the adhesion of the molten film to the cooling roll is sufficiently maintained, the generation of streaks on the film surface is suppressed, and an optical film having a uniform thickness is obtained. The glass transition temperature of the cyclic olefin polymer measured at a temperature rising rate of 10 ° C./min with a differential scanning calorimeter (hereinafter referred to as DSC), particularly the surface temperature of the first cooling roll −40 ° C. to the glass transition temperature + 20 ° C. It is preferable to set it as glass transition temperature -35 degreeC-glass transition temperature +10 degreeC especially.

  Examples of molding conditions other than those described above for the T-die melt extrusion method in the present invention include screw rotation speed and discharge rate. These conditions may be appropriately selected according to the thickness of the film, the take-up speed, and the like. Further, in order to suppress thermal decomposition and yellowing due to oxidation during melting, it is preferable to purge the inside of the hopper, the extruder cylinder, etc. with a nitrogen purge or vacuum.

  Below, although an example of the shaping | molding apparatus at the time of implementing the manufacturing method of this invention is described, this invention is not restrict | limited to these.

  Typical examples of the extruder that can be used in the present invention include a single-screw extruder, a co-rotating twin-screw extruder, a different-direction rotating twin-screw extruder, and a tandem extruder. If a volatile component such as water is contained during extrusion, the film appearance deteriorates during the extrusion of the optical film. Therefore, these extruders are equipped with a vacuum vent, a hopper dryer, etc. for removing the volatile component. What was done is used suitably. Also, the cylinder diameter, cylinder length to cylinder diameter ratio (L / D), compression ratio, screw design should be optimized according to production speed, film dimensions, etc., especially when producing optical film, discharge speed Is stabilized, frictional heat generation is suppressed, and the melting temperature of the resin can be maintained below the decomposition temperature.

  In the production method of the present invention, it is preferable to use a gear pump having a pressure increasing function and a metering function in combination with an extruder in order to stabilize the discharge speed and improve the thickness accuracy in the flow direction of the optical film. Further, when a foreign material is filtered through a filter system described later, if the pressure loss in the container exceeds the extrusion pressure of the extruder, it is necessary to increase the pressure with a gear pump. However, since the molten resin stays in the gear pump and may be thermally decomposed or yellowed, a structure that can prevent the stay is desirable.

  Also, for the purpose of removing foreign substances typified by agglomerates such as fibers, metals, sand, resins or additives, or for the purpose of removing resin degradation products generated in extruders and gear pumps, T-die melt extrusion It is preferable to install a filter in the process. Such a filter may generally be used to filter foreign matter using a metal mesh made of stainless steel or the like called a screen mesh, and particularly when an optical film is manufactured, the requirements for the appearance of the film are severe. Foreign matter may not be completely removed by filtration with a screen mesh. In such a case, a filter obtained by laminating a metal mesh made of an alloy such as stainless steel and sintering each layer; a filter that is a metal mesh in which fine fibers of stainless steel are knitted intricately and that sinters contacts between fibers; metal It is preferable to use a filter obtained by sintering powder (hereinafter collectively referred to as a sintered metal filter), and the sintered metal filter has high filtration efficiency and low filtration resistance with respect to the screen mesh. It is generally known that it can be obtained. Such sintered metal filters are disclosed in, for example, JP-A-07-124426, JP-A-08-10521, JP-A-10-337415, JP-A-11-76721, and the like. Further, a method for filtering foreign substances by passing through a filter system in which a large number of sintered metal filters are formed in a tube or disk shape in a container is disclosed in, for example, Japanese Patent Application Laid-Open No. 08-10522. Since a higher filtration efficiency and lower filtration resistance can be obtained than when a filter is used alone, it can be suitably used in the production method of the present invention. However, there is a possibility of thermal decomposition or yellowing in the filter system, so it is necessary to pay attention to the residence time in the filter system, and the filter system has a structure that makes it difficult to stay in the dead space. It is desirable to be.

  In the manufacturing method of the present invention, since the film is shaped into a wide film in the T die, the dimensions of the film are mainly determined by the T die. The flow path in the T die may be selected as appropriate, and the die generally includes a straight manifold type, a coat hanger type, a fish tail type, and a coat hanger manifold type. Among them, the thickness accuracy of the obtained optical film is improved. When importance is attached, it is preferable to use a manifold type die. Moreover, the gap adjustment of the lip which is an exit part is one of the important factors which determine the thickness accuracy of a film.

  Optical films are required to have very strict thickness accuracy. As an example, when used in a retardation film, the amount of retardation is the product of the birefringence of the medium and the optical path length. Unevenness occurs. However, it takes time to adjust the thickness of the lip accurately even if it takes an expert.In recent years, an automatic thickness control system using a computer has been introduced to improve not only the film thickness accuracy but also the yield. It contributes greatly. And, as such a method, there is a method of measuring the thickness of the film online, and automatically adjusting the gap of the lip and adjusting the speed of the gear pump based on the result, for example, JP-A-10-58518, Examples of methods for automatically adjusting the lip disclosed in Japanese Patent Application Laid-Open No. 2000-127226 include a heat bolt method, a robot method, a lip heater method, a piezoelectric element method, and the like, and these are also included in the manufacturing method of the present invention. The method can additionally be used.

  Further, since the lip of the T die is an exit portion, when the lip portion that comes into contact has irregularities, the irregularities are transferred to the surface of the optical film, and the shape is solidified by a cooling roll, resulting in a so-called die line. Therefore, it is desirable to reduce the surface roughness of the lip portion by a method such as electrolytic polishing. Further, even if the surface roughness of the lip portion is small, if the thermally decomposed resin adheres to the lip portion and becomes a so-called eye, unevenness is generated on the surface of the lip, which causes a die line. It is important to prevent the resin from adhering to the lip in order to prevent it from being easily observed. In the production method of the present invention, a lip coated with chromium or ceramic can be suitably used. Further, since the resin tends to stay in the edge portion of the lip, the edge of the lip is preferably as sharp as possible, and particularly preferably 0.1 mmR or less.

  In the production method of the present invention, the molten film extruded from the slit of the T-die is brought into close contact with a cooling roll and cooled. Such a cooling roll and the first cooling roll when there are a plurality of cooling rolls are generally called a cast roll or a casting roll. And the surface of the 1st cooling roll which a molten film contacts is desired to have a small surface roughness for the same reason as the lip of the T die. In addition, when there are a plurality of cooling rolls, it is important to keep the rotation speed of the first cooling roll and the other cooling rolls constant. If the rotation speed is uneven, streaks in the width direction are formed on the film surface. May occur.

  And in order to cool the obtained optical film more efficiently, it is preferable to use a method of cooling the optical film wound around the first cooling roll from the opposite surface of the first cooling roll, such a method. Examples of the method include an air chamber method, a touch roll method, an air knife method, a rubber roll method, a cooling drum method, an ear press roll method, and an electrostatic peening method. As touch roll methods, for example, JP 2002-36332 A, JP 97/28950 A, JP 11-235747 A, etc. have proposed touch rolls that can be elastically deformed. In these cases, A thinner film can be formed than using a high-rigidity touch roll, and these methods can also be employed in the present invention. In addition, by suppressing the film from the opposite surface of the first cooling roll with a touch roll, there is an effect of flattening the surface roughness or making it difficult to cause molecular orientation in the take-off direction, so these touch rolls should preferably be used. Can do. Of course, the cooling from the opposite surface of the first cooling roll is not particularly performed, and may be allowed to cool.

  Since the surface temperature of the cooling roll greatly affects the appearance of the obtained optical film, it is desirable to control the surface temperature of the cooling roll with an accuracy of 0.1 ° C. In this case, as described above, the ring temperature measured by DSC is used. The glass transition temperature of the olefin polymer is preferably set to −40 ° C. to glass transition temperature + 20 ° C. In this case, pressurized water or oil is used as a medium for controlling the roll temperature. Note that oil temperature control is preferable because of excellent temperature control accuracy.

  A slitter for cutting both ends of the obtained optical film may be installed, and the slitter at that time is not limited. Among them, since the optical film obtained by the present invention is relatively hard, it is easy to suppress the occurrence of fine cracks on the fracture surface of the film, so the shear cutter that presses and cuts the rotary blade from both sides of the film It is preferable to use a slitter called.

  Further, in order to prevent foreign matters such as fibers from adhering to the surface of the obtained optical film, it is preferable to perform masking treatment on one or both sides of the film, and it is preferable to add an apparatus for masking treatment.

  There is no restriction | limiting in particular in the winding machine of the obtained optical film, It is preferable to use the accumulator equipment for performing balance adjustment of taking-up speed and winding speed among them.

  The optical film obtained by the production method of the present invention can be stretched for purposes such as improving mechanical strength and adjusting optical properties, and can be stretched when producing a stretched film. The stretching process includes, for example, a process of continuously performing in a T-die melt extrusion process; a process of winding the optical film once and then subjecting the film to a stretching process apparatus; In addition, the uniaxial direction or the biaxial direction is selected depending on the purpose of the stretching direction, and when stretching in the uniaxial direction, the length in the film width direction is restricted so as not to change during stretching with respect to the length before stretching. It is more preferable to obtain a stretched film having uniform optical properties. Examples of the uniaxial stretching method include a method of stretching with a tenter, a method of rolling and stretching with a calender, a method of stretching between rolls, and the like. As a biaxial stretching method, for example, a method of stretching with a tenter, a tube is expanded. And stretching method.

  When the optical film obtained by the present invention is used as a stretched optical film, the stretching condition is that the film is less likely to have thickness unevenness, and the resulting film is excellent in mechanical properties and optical properties. It is particularly preferable to stretch the film in the range of a stretching ratio of 1.1 to 3 times under a stretching temperature condition that is 1 to 40 ° C. higher than the glass transition temperature of the cyclic olefin polymer.

  The optical film obtained by the present invention may contain an additive within a range not exceeding the gist of the invention. As an addition method, a method of adding in a step of producing a cyclic olefin polymer, a T-die melt extrusion step Examples thereof include a method of dry blending the cyclic olefin polymer and the additive, supplying them to a hopper, and melt-kneading them in an extruder. Examples of additives include surfactants, polymer electrolytes, conductive complexes, inorganic fillers, pigments, dyes, antioxidants, hindered amine light stabilizers, ultraviolet absorbers, antistatic agents, antiblocking agents, lubricants, etc. Common additives are mentioned.

  Antioxidants include, for example, hindered phenolic antioxidants, phosphorus antioxidants, other antioxidants, etc., and these antioxidants may be used alone or in combination. Also good. And, since the antioxidant effect is synergistically improved, it is preferable to use a hindered phenol antioxidant and a phosphorus antioxidant in combination, and in that case, 100 parts by weight of the hindered phenol antioxidant It is preferable to use a phosphorus-based antioxidant mixed in an amount of 100 to 500 parts by weight. Moreover, as addition amount of antioxidant, 0.001-2 weight part is preferable normally with respect to 100 weight part of resin, and it is especially preferable that it is the range of 0.01-1 weight part.

  Examples of the hindered phenol-based antioxidant include pentaerythritol-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate), thiodiethylene-bis (3- (3,5-dioxy). -T-butyl-4-hydroxyphenyl) propionate), octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate, N, N'-hexane-1,6-diylbis (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionamide), diethyl ((3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl) methyl) phosphate, 3,3 ′, 3 ″, 5,5 ′, 5 ″ -hexa-t-butyl-a, a ′, a ″-(mesitylene-2,4,6-triyl) tri-p-cle , Ethylenebis (oxyethylene) bis (3- (5-t-butyl-4-hydroxy-m-tolyl) propionate), hexamethylene-bis (3- (3,5-di-t-butyl-4) -Hydroxyphenyl) propionate), 1,3,5-tris (3,5-di-t-butyl-4-hydroxybenzyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H ) -Trione, 1,3,5-tris ((4-tert-butyl-3-hydroxy-2,6-xylyl) methyl) -1,3,5-triazine-2,4,6 (1H, 3H, 5H) -trione, 2,6-di-t-butyl-4- (4,6-bis (octylthio) -1,3,5-triazin-2-ylamino) phenol, 3,9-bis (2- ( 3- (3-t-butyl-4-hydroxy-5-methyl Butylphenyl) propionyloxy) -1,1-dimethylethyl) -2,4,8,10-spiro (5,5) undecane.

  Examples of phosphorus antioxidants include tris (2,4-di-t-butylphenyl) phosphite, bis (2,4-bis (1,1-dimethylethyl) -6-methylphenyl) ethyl ester phosphorous Acid, tetrakis (2,4-di-t-butylphenyl) (1,1-biphenyl) -4,4'-diylbisphosphonite, bis (2,4-di-t-butylphenyl) pentaerythritol di Phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, bis (2,4-dicumylphenyl) pentaerythritol-diphosphite, tetrakis (2,4-t-butyl) Phenyl) (1,1-biphenyl) -4,4′-diylbisphosphonite, di-t-butyl-m-cresyl-phosphonite, and the like. It is.

  In addition, the hindered amine light stabilizer preferably has a molecular weight of 1,000 or more, particularly preferably 1,500 or more, since it is excellent in thermal coloring suppression effect. Furthermore, the addition amount of the hindered amine light stabilizer is preferably 0.01 to 1.5 parts by weight with respect to 100 parts by weight of the resin because it is excellent in the effect of preventing thermal coloring and the effect of light stabilization. 0.05 part by weight to 1.0 part by weight is preferable, and 0.1 part by weight to 0.5 part by weight is more preferable.

  Examples of such a hindered amine light stabilizer include poly ((6-morpholino-s-triazine-2,4-diyl) ((2,2,6,6-tetramethyl-4-piperidyl) imino) hexamethylene. ((2,2,6,6-tetramethyl-4-piperidyl) imino)) (molecular weight 1,600), poly ((6- (1,1,3,3-tetramethylbutyl) amino-1,3 , 5-Triazine-2,4-diyl) ((2,2,6,6-tetramethyl-4-piperidyl) imino) hexamethylene ((2,2,6,6-tetramethyl-4-piperidyl) imino )) (Molecular weight 2,000-3,100), dibutylamine-1,3,5-triazine-N, N′-bis (2,2,6,6-tetramethyl-4-piperidyl-1,6- Hexamethylenediamine-N- 2,2,6,6-tetramethyl-4-piperidyl) butylamine polycondensate (molecular weight 2,600-3,400), N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis (N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino) -6-chloro-1,3,5-triazine condensate (molecular weight 2,000 or more), succinic acid Examples thereof include dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine condensate (molecular weight 3,100 to 4,000), and these are used in one or more kinds. be able to.

  As the ultraviolet absorber, for example, an ultraviolet absorber such as benzotriazole, benzophenone, triazine, or benzoate can be added as necessary.

  Moreover, in the production method of the present invention, a lubricant may be added for the purpose of suppressing frictional heat generation during T-die melt extrusion, improving the stability of extrusion, and the addition amount of the lubricant is preferably 1 to 10,000 ppm. 5 to 2000 ppm is preferable, and 10 to 500 ppm is more preferable. Examples of such lubricants include aliphatic hydrocarbon lubricants such as liquid paraffin, natural paraffin, and polyethylene wax; higher aliphatic alcohols and higher fatty acid lubricants such as cetyl alcohol, stearyl alcohol, and stearic acid; stearamide; Aliphatic amide type lubricants such as oleic acid amide, palmitic acid amide, methylene bisstearamide; metal soap type lubricants such as calcium stearate, zinc stearate, magnesium stearate, barium stearate; butyl stearate, ethylene glycol stearate And fatty acid ester-based lubricants; composite lubricants and the like.

  The optical film obtained by the present invention is preferably a film having a total light transmittance of 85% or more and a haze of 2% or less because it is excellent as a film used as an optical component. The thickness of the optical film is preferably 10 to 300 μm, and particularly preferably 10 to 200 μm, since the thickness accuracy, mechanical properties, and appearance of the film are excellent.

  As is apparent from the above, in the production method of the present invention, an optical film can be supplied with high productivity by the T-die melt extrusion method. Since the optical film obtained by the present invention is excellent in excellent surface smoothness and thickness accuracy, it can be suitably used as a transparent electrode film, a polarizing film protective film, a retardation film and the like used in LCDs.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, a present Example does not restrict | limit this invention at all. The raw materials and availability used in the examples are as follows, and the other reagents were commercially available unless otherwise noted.

Dicyclopentadiene: Wako Pure Chemicals Reagent grade 1 Tricyclodecane vinyl ether: TCD-VE made by Maruzen Petrochemical
Hydroquinone: Wako Pure Chemicals Reagent grade The physical properties shown in the examples were measured by the following methods.

~ Weight average molecular weight ~
It calculated | required by polystyrene conversion using the gel permeation chromatography (GPC, the Tosoh Corporation make HLC-802A).

~ ¹ H-NMR measurement Using a nuclear magnetic resonance measuring apparatus (manufactured by JEOL Ltd., trade name: JNM-GSX270 type), ¹ H-NMR is measured in heavy toluene at 60 ° C to calculate the composition and hydrogenation rate. did.

~Glass-transition temperature~
A differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd., trade name DSC200) was used, and the temperature was measured at a heating rate of 10 ° C./min.

~ Total light transmittance ~
The total light transmittance at the center of the film was measured using an ultraviolet-visible spectrometer (V530) manufactured by JASCO Corporation.

~ Surface smoothness ~
Using a laser microscope (VK-8550) manufactured by Keyence Corporation, the center line average roughness (Ra) was determined, and when this value was small, the surface smoothness was excellent.

Reference Example 1 (Synthesis of polymerizable monomer)
A 300 ml glass distillation apparatus was charged with 100 ml of dicyclopentadiene, heated to 220 ° C. with a mantle heater, and the fraction having a boiling point of 39.5 ° C. of cyclopentadiene produced by thermal decomposition was cooled in a dry ice methanol bath. It separated by the technique of liquefying in the receiver.

  Next, 16.26 g (0.247 mol) of cyclopentadiene, 76 g (0.37 mol) of tricyclodecane vinyl ether and 0.1 g (1 mmol) of hydroquinone were charged into a 300 ml stainless steel autoclave and purged with nitrogen. Then, it heated at 220 degreeC and made it react for 5 minutes in a heating state. Thereafter, the reactor is cooled, tricyclodecane vinyl ether as a raw material is separated from the contents by distillation under reduced pressure, and tricyclodecane vinyl ether added with cyclopentadiene (tricyclodecanyl-tricyclodecenyl ether) (monomer 1 ) As a main component was separated. Yield was 8 grams.

In addition, in addition to the monomer 1 obtained by adding 1 mol of cyclopentadiene represented by the general formula (2) (component I), the obtained monomer 1 further contains cyclopentadiene in the component I represented by the general formula (3). What was added (component II) was included, and the abundance ratio of these components was component I: component II = 90: 10 (weight ratio). The abundance ratio of the product coincided with that calculated from the intensity ratio of hydrogen in the double bond portion, methine, and methylene portion by ¹ H-NMR.

合成例１（環状オレフィン重合体の合成）
窒素置換した３００ｍｌの反応器に、シクロヘキサン１００ｍｌ、参考例１で得られたモノマー１ ８グラム、触媒として六塩化タングステンの濃度０．１モル／ｌのクロロベンゼン溶液２ｍｌ及びジエチルアルミニウムクロライドの濃度０．１モル／ｌのクロロベンゼン溶液０．２ｍｌを仕込み、窒素気流下、６０℃で、攪拌速度１００ｒｐｍにて攪拌下、５時間反応させた。得られた反応溶液をメタノールに注ぎ単離し、メタノールで数回洗浄を行った後、４０℃で一昼夜減圧乾燥を行い、７．９ｇの未水素添加重合体を得た。ＧＰＣ測定により、得られた未水素添加重合体の重量平均分子量は１２００００であった。

Synthesis Example 1 (Synthesis of cyclic olefin polymer)
Into a 300 ml reactor purged with nitrogen, 100 ml of cyclohexane, 8 grams of the monomer obtained in Reference Example 1, 2 ml of a chlorobenzene solution having a concentration of 0.1 mol / l tungsten hexachloride as a catalyst and a concentration of 0.1 ml of diethylaluminum chloride 0.2 ml of a mol / l chlorobenzene solution was charged, and the mixture was reacted at 60 ° C. under a nitrogen stream at a stirring speed of 100 rpm for 5 hours. The obtained reaction solution was poured into methanol, isolated, washed several times with methanol, and then dried under reduced pressure at 40 ° C. overnight to obtain 7.9 g of an unhydrogenated polymer. The weight average molecular weight of the obtained non-hydrogenated polymer was 120,000 by GPC measurement.

  7 grams of the obtained unhydrogenated polymer, 30 grams of toluene and 0.1 mg of ruthenium hydride triphenylphosphine complex were charged into a 100 cc stainless steel autoclave and stirred to obtain a uniform solution. Subsequently, a hydrogenation reaction was performed with stirring for 4 hours at a hydrogen gas pressure of 10 MPa and a temperature of 160 ° C. After cooling the reaction solution, excess hydrogen was released and depressurized, and then the reaction solution was poured into a large amount of hydrochloric acid-methanol solution, isolated, and dried under reduced pressure at 50 ° C. overnight to obtain 7 g of a cyclic olefin polymer. The cyclic olefin polymer had a weight average molecular weight of 150,000 and a glass transition temperature of 171 ° C. The hydrogenation rate was 99.5%.

Synthesis Example 2 (Synthesis of cyclic olefin polymer)
Into a 500 ml reactor purged with nitrogen, 180 ml of cyclohexane, 20 grams of the monomer 1 obtained in Reference Example 1, 4 ml of a chlorobenzene solution having a concentration of 0.1 mol / l tungsten hexachloride as a catalyst and a concentration of 0.1 ml of diethylaluminum chloride A 0.4 ml mol / l chlorobenzene solution was charged, reacted under a nitrogen stream at 60 ° C. with stirring at 100 rpm for 5 hours, followed by 0.2 mg of ruthenium hydride triphenylphosphine complex and hydrogen. A hydrogenation reaction was performed by injecting gas and stirring at a temperature of 160 ° C. for 5 hours under a pressure of 10 MPa. After cooling the reaction solution, excess hydrogen was released, and after depressurization, the reaction solution was poured into a large amount of hydrochloric acid-methanol solution, isolated and dried under reduced pressure at 50 ° C. overnight to obtain 14 g of a cyclic olefin polymer. The cyclic olefin polymer had a weight average molecular weight of 120,000 and a glass transition temperature of 171 ° C. The hydrogenation rate was 99.4%.

Synthesis Example 3 (Synthesis of cyclic olefin polymer)
In a 500 ml reactor purged with nitrogen, 180 ml of cyclohexane, 20 grams of monomer 1 obtained in Reference Example 1, 0.015 g of 1-hexene, 4 ml of a chlorobenzene solution of tungsten hexachloride at a concentration of 0.1 mol / l and diethylaluminum chloride 0.4 ml of chlorobenzene solution having a concentration of 0.1 mol / l was prepared and reacted for 5 hours at 60 ° C. with stirring at a stirring speed of 100 rpm under a nitrogen stream, followed by 0.2 mg of ruthenium hydride triphenylphosphine complex. Then, hydrogen gas was injected and hydrogenation reaction was carried out under a pressure of 10 MPa and at a temperature of 160 ° C. with stirring for 5 hours. After cooling the reaction solution, excess hydrogen was released, and after depressurization, the reaction solution was poured into a large amount of hydrochloric acid-methanol solution, isolated and dried under reduced pressure at 50 ° C. overnight to obtain 14 g of a cyclic olefin polymer. The cyclic olefin polymer had a weight average molecular weight of 60,000 and a glass transition temperature of 170 ° C. The hydrogenation rate was 99.8%.

Example 1
The polymer obtained in Synthesis Example 1 was put into the film forming apparatus shown in FIG. The filming conditions at that time were a T die outlet temperature of 265 ° C., a take-up speed of 10 m / min, a first cooling roll surface temperature of 135 ° C., a width of about 500 mm, and a thickness of about 100 μm. The film was cut into a 200 mm square, and the total light transmittance and Ra were measured. The results are shown in Table 1.

  The obtained film was an optical film excellent in optical isotropy, and was excellent in surface smoothness and thickness accuracy.

Example 2
The polymer obtained in Synthesis Example 2 was put into the film forming apparatus shown in FIG. The filming conditions at that time were a melt resin temperature of 270 ° C. at the outlet of the T die, a take-up speed of 30 m / min, a first cooling roll surface temperature of 135 ° C., a width of about 500 mm, and a thickness of about 100 μm. The film was cut into a 200 mm square, and the total light transmittance and Ra were measured. The results are shown in Table 1.

  The obtained film was an optical film excellent in optical isotropy, and was excellent in surface smoothness and thickness accuracy.

Example 3
The polymer obtained in Synthesis Example 3 was put into the film forming apparatus shown in FIG. The film forming conditions at that time were a molten resin temperature of 275 ° C. at the exit of the T die, a take-up speed of 50 m / min, a first cooling roll surface temperature of 135 ° C., a film having a width of about 500 mm and a thickness of about 100 μm. The film was cut into a 200 mm square, and the total light transmittance and Ra were measured. The results are shown in Table 1.

  The obtained film was an optical film excellent in optical isotropy, and was excellent in surface smoothness and thickness accuracy.

Comparative Example 1
The polymer obtained in Synthesis Example 1 was put into the film forming apparatus shown in FIG. The film forming conditions at that time were a molten resin temperature of 275 ° C. at the outlet of the T die, a take-up speed of 8 m / min, a first cooling roll surface temperature of 135 ° C., a film having a width of about 500 mm and a thickness of about 100 μm. The film was cut into a 200 mm square, and the total light transmittance and Ra were measured. The results are shown in Table 1.

  The obtained film had large Ra and inferior surface smoothness.

Comparative Example 2
The polymer obtained in Synthesis Example 1 was put into the film forming apparatus shown in FIG. The filming conditions at that time were a melt resin temperature of 275 ° C. at the outlet of the T die, a take-up speed of 110 m / min, a first cooling roll surface temperature of 135 ° C., a film having a width of about 500 mm and a thickness of about 100 μm. The film was cut into a 200 mm square, and the total light transmittance and Ra were measured. The results are shown in Table 1.

  The obtained film had large Ra and inferior surface smoothness.

An example of an optical film forming apparatus used in the production method of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Twin screw extruder 2; Vacuum vent 3; Diverter valve 4; Gear pump 5; Screen changer 6; T die 7; First cooling roll 8;

Claims (2)

The following general formula (1)

(Here, X and Y independently represent a methylene group, an oxygen atom, a sulfur atom or a tellurium atom, and n represents 0 or a positive integer.)
When a cyclic olefin polymer composed of repeating units represented by the following formula is extruded as a molten film by a T-die melt extrusion method and the molten film is cooled by one or a plurality of cooling rolls, a take-up speed of 10 to 100 m is obtained. The manufacturing method of the optical film characterized by taking out in the range of / min. Among the cooling rolls, the glass transition temperature of the cyclic olefin polymer measured from the surface temperature of the first cooling roll installed at the most upstream position on the T die side with a differential scanning calorimeter at a heating rate of 10 ° C./min. The method for producing an optical film according to claim 1, wherein the molten film is cooled by setting the glass transition temperature to + 20 ° C.

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