JPWO2019163637A1 - Method for manufacturing cyclic olefin resin film, cyclic olefin resin film, composite film - Google Patents

Abstract

Using an extruder having a supply unit, a compression unit, and a measuring unit to which a raw material resin containing a cyclic olefin resin and an elastomer having a specific melt flow rate is supplied, the resin transportation efficiency of the supply unit is 0.75 ≦ resin transportation of the supply unit. A method for producing a cyclic olefin resin film, which comprises a step of supplying and melting the raw material resin under the condition of satisfying the efficiency ≦ 1.0 and melt-extruding the molten resin extruded from the extrusion port into a film from a die. A composite film having an olefin resin film and the cyclic olefin resin film.

Description

The present disclosure relates to a method for producing a cyclic olefin resin film, a cyclic olefin resin film, and a composite film.

In recent years, cyclic olefin resin films have been attracting attention as films having small changes in optical characteristics with respect to changes in environmental temperature and humidity.
The cyclic olefin resin film is used for various purposes such as a polarizing plate, an optical film used for a liquid crystal display device as a film for displaying a liquid crystal, a film for protecting the back surface of a solar cell, and the like.
The cyclic olefin resin film is formed, for example, by melting the cyclic olefin resin with an extruder and extruding it into a die, discharging the molten resin from the die into a sheet, and cooling and solidifying the film.
It is also attempted to improve the physical properties of the cyclic olefin resin film by containing an elastomer.

As such a cyclic olefin resin film or a method for producing the same, those described in Japanese Patent No. 5646793, Japanese Patent Application Laid-Open No. 2008-137328, or International Publication No. 2017/126572 are known.
Japanese Patent No. 5646793 describes a cyclic olefin resin having a refractive index of n1 and a glass transition point (Tg) of 170 ° C. or higher, and a styrene resin having a refractive index of n2 and Δn = │n2-n1│ of 0.012 or less. The internal haze value measured in a polyethylene glycol solution for a test piece having a thickness of 100 μm, which contains an elastomer and conforms to JIS K7136, is 1.0% or less, and the cyclic olefin resin has a load of 2.16 kg at 270 ° C. A transparent film containing at least the above-mentioned styrene-based elastomer having a smaller MI than the melt index (MI) in the above is described.
Japanese Patent Application Laid-Open No. 2008-137328 describes a method for producing an optical film, which comprises melt-extruding resin pellets using an extruder having an opening in an inert gas atmosphere having an oxygen concentration of 10 ppm or less. Is described.
In International Publication No. 2017/126572, a cylinder having a supply port for supplying the raw material resin and an extrusion port for extruding the molten resin obtained by melting the raw material resin, and a screw shaft and a spiral arrangement around the screw shaft are arranged. An extruder having a plastic extrusion, a screw that rotates in the cylinder, and an extruder having a supply unit, a compression unit, and a measuring unit in the cylinder in this order from the side of the supply port along the screw shaft. The raw material resin is supplied and melted under the condition that the supply unit resin transport efficiency calculated by the following formula satisfies 0.75 ≤ supply unit resin transport efficiency ≤ 1.0, and is extruded from the extrusion port. A method for producing a thermoplastic resin film having a step of melt-extruding the molten resin from a die into a film is described.

W: Screw flight interval (mm) in the supply section
Hf: Groove depth (mm) in the supply section
D: Cylinder inner diameter (mm)
Ψ: Screw flight angle (°) at the supply section
Q: Extruded amount of molten resin (kg / h)
ρ: Specific gravity of raw material resin (g / cm ³ )
N: Screw rotation speed per minute (rpm)
Compression ratio: Volume per screw flight pitch in the supply section / Volume per screw flight pitch in the weighing section

Among the cyclic olefin resin films, the cyclic olefin resin imparted with heat resistance has a small quality change in the display manufacturing process that becomes high temperature, and has durability that can be used in a harsh environment such as in an automobile in summer. For these reasons, it is expected to be widely used as an optical film.
The highly heat-resistant cyclic olefin resin has excellent characteristics as an optical film, but may be required to have improved physical properties.
One problem that needs to be improved is both the surface shape of the film and the impact strength. If the glass transition point (Tg) of the cyclic olefin resin is raised in order to impart heat resistance, the film becomes brittle, causing problems such as cracking during bending and dust generation during cutting, which may reduce the suitability of the display manufacturing process. is there.

Japanese Patent No. 5646793 discloses a method of mixing a styrene-based elastomer with a cyclic olefin resin in order to improve the brittleness of the cyclic olefin resin film.
However, the present inventors have found that in the cyclic olefin resin film mixed with the elastomer described in Japanese Patent No. 5646793, the generation of foreign matter in the film may be a problem.
When a cyclic olefin resin film is produced by a melt extrusion method, foreign matter (hereinafter, may be simply referred to as “foreign matter”) may be generated due to thermal oxidative deterioration of the resin or the like. In particular, in the case of an optical film, when foreign matter contained in the film becomes a point defect, and the light transmission is lowered due to the point defect, unevenness is increased, and surface smoothness is lowered. The surface condition of the film tends to deteriorate.
Among them, the highly heat-resistant cyclic olefin resin has a high glass transition temperature (Tg), so that the processing temperature tends to be high, and such foreign matter is likely to be generated.
Further, as described in Japanese Patent No. 5646793, when an elastomer is mixed in order to improve brittleness, it is considered that the generation of foreign matter becomes more remarkable due to an increase in thermal history during mixing and poor dispersion of the elastomer. That is, when an elastomer is mixed for the purpose of improving brittleness, it is considered that the generation of foreign substances and the resulting decrease in surface smoothness become more serious problems.

As a measure for suppressing the generation of foreign matter, for example, in Japanese Patent Application Laid-Open No. 2008-137328, the oxygen concentration at the opening of the extruder used for melt-forming is set to an inert gas atmosphere of 10 ppm or less. It is disclosed that the thermal oxidative deterioration of the resin is suppressed.
However, when the present inventors produce a cyclic olefin resin film in which an elastomer is mixed by the method described in JP-A-2008-137328, the generation of foreign matter in the film may become a problem. I found.
The method described in JP-A-2008-137328 is an effective method in that it suppresses thermal oxidative deterioration during melt film formation of a cyclic olefin resin, but when an elastomer is mixed to improve brittleness. It is considered that this is because the effect is not sufficient for the generation of foreign matter and the decrease in surface smoothness due to the increase in thermal history during mixing and poor dispersion of the elastomer.

The method described in International Publication No. 2017/126572 is an effective method in that it suppresses thermal oxidative deterioration during melt film formation of a cyclic olefin resin. However, no consideration has been given to a method for suppressing the generation of foreign matter when an elastomer is mixed to improve brittleness.

An object to be solved by one embodiment of the present disclosure is to provide a method for producing a cyclic olefin resin film, which can suppress the generation of foreign substances and obtain a cyclic olefin resin film having excellent impact strength.
An object to be solved by another embodiment of the present disclosure is to provide a cyclic olefin resin film having excellent surface smoothness and excellent impact strength, and a composite film having the cyclic olefin resin film. ..

The means for solving the above problems include the following aspects.
<1> A cylinder having a supply port for supplying a cyclic olefin resin and a raw material resin containing an elastomer and an extrusion port for extruding a molten resin obtained by melting the raw material resin.
Has a screw shaft and a spirally arranged flight around the screw shaft,
Equipped with a screw that rotates in the above cylinder,
An extruder having a supply unit, a compression unit, and a measuring unit in this order from the side of the supply port along the screw shaft is used in the cylinder.
The raw material resin is supplied and melted under the condition that the supply unit resin transport efficiency calculated by the following formula satisfies 0.75 ≤ supply unit resin transport efficiency ≤ 1.0.
It has a step of melt-extruding the molten resin extruded from the extrusion port from a die into a film.
The glass transition temperature of the resulting cyclic olefin resin film when the Tg ℃, Tg + 50 ℃, melt flow rate of the elastomer in the load 49N is less than 0.3 cm ³ / 10min or more 9.0 cm ³ / 10min,
A method for producing a cyclic olefin resin film.


W: Screw flight interval (mm) in the supply section
Hf: Groove depth (mm) in the supply section
D: Cylinder inner diameter (mm)
Ψ: Screw flight angle (°) at the supply section
Q: Extruded amount of molten resin (kg / h)
ρ: Specific gravity of raw material resin (g / cm ³ )
N: Screw rotation speed per minute (rpm)
Compression ratio: Volume per screw flight pitch in the supply section / Volume per screw flight pitch in the metering section <2> The concentration of the elastomer contained in the obtained cyclic olefin resin film is the total concentration of the obtained cyclic olefin resin film. The method for producing a cyclic olefin resin film according to <1> above, which is 1% by volume or more and less than 20% by volume with respect to the mass.
<3> The method for producing a cyclic olefin resin film according to <1> or <2>, wherein the elastomer is a styrene-based thermoplastic elastomer.
<4> The ratio of the melt flow rate of the obtained cyclic olefin resin film at Tg + 50 ° C. and load 49N to the melt flow rate of the elastomer at Tg + 50 ° C. and load 49N is 80% or more and 120% or less. The method for producing a cyclic olefin resin film according to any one of 1> to <3>.
<5> The above <1> to <5>, further including a step of introducing the molten resin obtained by the step of melt-extruding into a film into a narrowing portion formed in the gap between a pair of smooth rolls and narrowing the pressure. The method for producing a cyclic olefin resin film according to any one of 4>.
<6> Cyclic olefin resin film
Contains cyclic olefin resins and elastomers
The number of foreign substances having a maximum diameter of 30 μm or more is 0.3 pieces / cm ² or less and the number of foreign substances having a maximum diameter of 5 μm or more and less than 30 μm is 100 pieces / cm ² or less per 100 μm of the thickness of the cyclic olefin resin film. Yes,
The glass transition temperature of the cyclic olefin resin film when the Tg ℃, Tg + 50 ℃, melt flow rate of the elastomer in the load 49N is less than 0.3 cm ³ / 10min or more 9.0 cm ³ / 10min,
Cyclic olefin resin film.
<7> The cyclic olefin resin film according to <6>, wherein the content of the elastomer is 1% by mass or more and less than 20% by mass with respect to the total mass of the cyclic olefin resin film.
<8> The cyclic olefin resin film according to <6> or <7>, wherein the elastomer is a styrene-based thermoplastic elastomer.
<9> The ratio of the melt flow rate of the cyclic olefin resin film at Tg + 50 ° C. and load 49N to the melt flow rate of the elastomer at Tg + 50 ° C. and load 49N is 80% or more and 120% or less. The cyclic olefin resin film according to any one of ~ <8>.
<10> The cyclic olefin resin film according to any one of <6> to <9>, wherein the average particle size of the elastomer is 100 nm or more and less than 1000 nm.
<11> The cyclic olefin resin film according to any one of <6> to <10>, wherein the Tg ° C. is 130 ° C. or higher and lower than 170 ° C.
<12> A composite film having the cyclic olefin resin film according to any one of <6> to <11> above.

According to one embodiment of the present disclosure, it is possible to provide a method for producing a cyclic olefin resin film, which can suppress the generation of foreign substances and obtain a cyclic olefin resin film having excellent impact strength.
According to another embodiment of the present disclosure, it is possible to provide a cyclic olefin resin film having excellent surface smoothness and excellent impact strength and a composite film having the cyclic olefin resin film.

FIG. 1 is a schematic view showing an example of an overall configuration of an apparatus for carrying out the method for producing a cyclic olefin resin film according to the present disclosure. FIG. 2 is a schematic view showing an example of the configuration of an extruder that can be used in the manufacturing method according to the present disclosure. FIG. 3 is an enlarged schematic view of the supply section of the extruder shown in FIG.

The contents of the present disclosure will be described in detail below. The description of the constituents described below may be based on the representative embodiments of the present disclosure, but the present disclosure is not limited to such embodiments.
In the present disclosure, "~" indicating a numerical range is used to mean that the numerical values described before and after the numerical range are included as the lower limit value and the upper limit value.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range described stepwise. .. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
Further, in the present disclosure, the amount of each component in the composition is the total amount of the plurality of applicable substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means.
Further, in the notation of a group (atomic group) in the present disclosure, the notation that does not describe substitution or non-substitution includes those having no substituent as well as those having a substituent. For example, the "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).
In the present disclosure, "(meth) acrylic" is a term used in a concept that includes both acrylic and methacrylic, and "(meth) acryloyl" is a term that is used as a concept that includes both acryloyl and methacryloyl. is there.
In the present disclosure, the term "(co) polymer" means either a homopolymer and / or a copolymer containing a specific structural unit.
In addition, the term "process" in the present disclosure is included in this term as long as the intended purpose of the process is achieved, not only in an independent process but also in the case where it cannot be clearly distinguished from other processes. Is done. Further, in the present disclosure, "% by mass" and "% by weight" are synonymous, and "parts by mass" and "parts by weight" are synonymous.
Further, in the present disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.
Unless otherwise specified, the weight average molecular weight (Mw) and the number average molecular weight (Mn) in the present disclosure use columns of TSKgel GMHxL, TSKgel G4000HxL, and TSKgel G2000HxL (all are trade names manufactured by Toso Co., Ltd.). It is a molecular weight converted by detecting with a solvent THF (tetrahydrofuran) and a differential refraction meter by a gel permeation chromatography (GPC) analyzer and using polystyrene as a standard substance.
Hereinafter, the present disclosure will be described in detail.

(Manufacturing method of cyclic olefin resin film)
The method for producing a cyclic olefin resin film according to the present disclosure (hereinafter, may be referred to as “the production method according to the present disclosure”) includes a supply port to which a cyclic olefin resin and a raw material resin containing an elastomer are supplied and the raw material resin. A cylinder having an extrusion port from which the molten molten resin is extruded, and a screw having a screw shaft and a screw arranged spirally around the screw shaft and rotating in the cylinder are provided in the cylinder. Using an extruder having a supply unit, a compression unit, and a measuring unit in this order from the side of the supply port along the screw shaft, the supply unit resin transport efficiency calculated by the following formula is 0.75 ≦ supply unit resin. A cyclic olefin resin obtained by supplying and melting the raw material resin under the condition that the transport efficiency ≤ 1.0 is satisfied, and melt-extruding the molten resin extruded from the extrusion port into a film from the die. the glass transition temperature of the film when the Tg ℃, Tg + 50 ℃, ( also referred to as "MFR".) the elastomer of melt flow rate at a load 49N is less than 0.3 cm ³ / 10min or more 9.0 cm ³ / 10min ..

W: Screw flight interval (mm) in the supply section
Hf: Groove depth (mm) in the supply section
D: Cylinder inner diameter (mm)
Ψ: Screw flight angle (°) at the supply section
Q: Extruded amount of molten resin (kg / h)
ρ: Specific gravity of raw material resin (g / cm ³ )
N: Screw rotation speed per minute (rpm)
Compression ratio: Volume per screw flight pitch in the supply section / Volume per screw flight pitch in the weighing section

In the present disclosure, the "raw material resin" means a resin composition containing not only resin components but also additives added as needed.
Further, in the present disclosure, the cyclic olefin resin film may be referred to as "film".

As a result of diligent studies, the present inventors have found that, according to the production method according to the present disclosure, a cyclic olefin resin film in which the generation of foreign substances is suppressed and the impact strength is excellent can be obtained.
The detailed mechanism by which the above effect is obtained is unknown, but it is speculated as follows.
In the step of melting and mixing the cyclic olefin resin and the elastomer, it is considered that the elastomer melts before the cyclic olefin resin. The molten elastomer acts like a cushion that keeps the friction between the cyclic olefin resins or between the cyclic olefin resin and the processing machine to an appropriate level, thereby suppressing local heat generation due to friction and causing foreign matter. It is considered that the occurrence of
On the other hand, if the melt viscosity of the elastomer is too high, the above-mentioned friction becomes too large, and foreign matter may be generated due to local heat generation. If the melt viscosity of the elastomer is too low, the above-mentioned friction becomes too small, the melting of the cyclic olefin and the elastomer is not stabilized, foreign matter is generated due to local heat generation, and undissolved residue that is not sufficiently melted remains. It may become a foreign substance.
Specifically, when the MFR of the elastomer is within 0.3 cm 3 ^/ 10min or more, the melt viscosity of the elastomer is lowered, suppressing friction acting between the machine and the cyclic olefin resin with each other, or a cyclic olefin resin is sufficiently low Therefore, it is considered that the generation of foreign matter due to local heat generation is suppressed.
When MFR of the elastomer is less than 9.0 cm 3 ^/ 10min, because the melt viscosity of the elastomer is not too low, as a result of friction acting between the machine and the cyclic olefin resin with each other or with cyclic olefin resin is increased, the cyclic olefin resin and It is considered that the melting of the elastomer is stabilized and the generation of foreign matter due to local heat generation is suppressed, or the cyclic olefins and elastomers that are not completely melted are less likely to be generated and become foreign matter.
When the resin transport efficiency of the supply unit is 0.75 or more, it is considered that the generation of foreign matter is suppressed because the elastomer is easily mixed sufficiently and the contact with oxygen is hardly suppressed.
When the resin transport efficiency of the supply unit is 1.0 or less, it is considered that the friction between the cyclic olefin resins is reduced and the generation of foreign substances is suppressed.
As described above, according to the method for producing a cyclic olefin resin film according to the present disclosure, a cyclic olefin resin film in which the generation of foreign substances is suppressed can be obtained.
Further, in the method for producing a cyclic olefin resin film according to the present disclosure, a cyclic olefin resin film having excellent impact strength can be obtained by containing an elastomer.
Further, since the impact strength is high, cracking during film transport and dust generation during cutting are suppressed, good transportability can be obtained, and the profitability during manufacturing is likely to be improved.

First, an outline of a manufacturing apparatus and a manufacturing method used in the method for manufacturing a cyclic olefin resin film according to the present disclosure will be described.
In each figure, the same reference numerals indicate the same or functionally similar elements.
FIG. 1 schematically shows an example of the overall configuration of a film forming apparatus (cyclic olefin resin film producing apparatus) for carrying out the method for producing a cyclic olefin resin film according to the present disclosure.
The film forming apparatus 10 shown in FIG. 1 stabilizes the hopper 12 into which the raw material resin is charged, the extruder 14 that melts the raw material resin supplied from the hopper 12, and the extrusion amount of the melted resin (molten resin). A gear pump 16, a filter 18 that filters the molten resin, a die 20 that melt-extrudes the molten resin into a film, and a plurality of cooling rolls that cool the high-temperature raw material resin discharged from the die 20 in multiple stages (hereinafter, cooling rolls). A contact roll (hereinafter, the contact roll may be referred to as a touch roll) that sandwiches the raw material resin 100 discharged from the die 20 between 22, 24, 26 (sometimes referred to as a casting roll) and the first cooling roll 22. ) 28 and. Although not shown, usually, a peeling roll for peeling the cyclic olefin resin film from the last third cooling roll 26 and a winder for winding the cooled film are provided.

FIG. 2 schematically shows an example of the configuration of an extruder that can be used in the manufacturing method according to the present disclosure.
As shown in FIG. 2, the extruder 14 includes a cylinder 44 and a screw 50 arranged in the cylinder.
The cylinder 44 has a supply port 52 to which the raw material resin is supplied and an extrusion port 54 from which the molten resin in which the raw material resin is melted is extruded. The inside of the cylinder 44 is sequentially arranged from the supply port 52 side along the screw shaft 46. A supply unit (region shown by A in FIG. 2) for transporting the raw material resin supplied from the supply port 52 while preheating, and a compression unit (region shown by B in FIG. 2) in which the raw material resin is kneaded and melted while being compressed. ), And a measuring unit (region shown by C in FIG. 2) that measures the molten resin and stabilizes the extrusion amount. FIG. 3 is an enlarged and schematic view of the supply section A of the extruder 14.
Further, the hopper 12 shown in FIG. 1 is attached to the supply port 52 of the cylinder 44 shown in FIG.

The screw 50 has a screw shaft 46 and a flight (hereinafter, may be referred to as a screw flight) 48 spirally arranged around the screw shaft 46, and is rotated in a cylinder 44 by a motor (not shown). Has been done.

Further, although not shown, in order to control the temperature of the resin in the cylinder 44, temperature control means (heater or the like) arranged in the longitudinal direction, for example, divided into 3 to 20, are provided around the cylinder 44. It is preferable to provide it.

When the cyclic olefin resin film is manufactured by the cyclic olefin resin film manufacturing apparatus 10 having the configuration shown in FIG. 2 and having the structure shown in FIG. 1, the raw material resin, which is the raw material resin, is charged into the hopper 12. , Is supplied into the cylinder 44 through the supply port 52 of the cylinder 44. The raw material resin supplied from the supply port 52 into the cylinder 44 is transported toward the extrusion port 54 while being preheated in the supply unit A by the rotation of the screw 50.

In addition, in order to prevent the molten resin from being oxidized by the remaining oxygen in the cylinder 44, it is more preferable to carry out the process in an inert air flow such as nitrogen or by using a vented extruder while evacuating. ..

The raw material resin preheated in the supply unit A is transported to the compression unit B. The compression portion B has a configuration in which the diameter of the screw shaft 46 gradually increases toward the extrusion port 54, and the raw material resin is between the inner wall of the cylinder 44 and the screw 50 as it is transported in the compression portion B. It is kneaded while being compressed with, and is heated and melted by coming into contact with the temperature-controlled cylinder 44. The resin melted in the compression unit B is transported to the measuring unit C, the molten resin is weighed in the measuring unit C, and the extrusion amount from the extrusion port 54 is stabilized.

The molten resin melted by the extruder 14 and extruded from the extrusion port 54 is continuously sent to the die 20 through the gear pump 16 and the filter 18 through the pipe 40. Then, the molten resin is melt-extruded from the die 20 into a film. The raw material resin 100 extruded into a film is shown in FIG.
The film-shaped raw material resin melt-extruded from the die 20 is sandwiched between the contact roll (touch roll) 28 and the first cooling roll 22, passes through the second cooling roll 24 and the third cooling roll 26, and is not shown. It is wound by the winder of.

In the method for producing a cyclic olefin resin film according to the present disclosure, when the cyclic olefin resin film is produced through the above steps, the supply unit resin transport efficiency calculated by the above formula is 0.75 ≦ supply unit resin. The raw material resin is supplied and melted under the condition that the transport efficiency ≦ 1.0 is satisfied, and the resin melted by the extruder is melt-extruded from the die into a film.

The reason why the generation of foreign substances is suppressed in the film obtained by the method for producing a cyclic olefin resin film according to the present disclosure is presumed as follows.
In the formula for calculating the resin transport efficiency of the supply unit in the present disclosure, the numerator "Q / N" of the fraction in the first term means the amount of molten resin extruded per rotation of the screw in the melt extrusion step. On the other hand, the denominator means the theoretical transport amount in the supply section in the cylinder, and means that by dividing the theoretical transport amount by the compression ratio, it is sufficient to transport with high efficiency regardless of the compression ratio. Further, (D / 90) ^0.5 is a correction coefficient for the cylinder inner diameter.

Then, the supply unit resin transport efficiency calculated by the formula of the supply unit resin transport efficiency in the present disclosure is 0.75 or more, that is, the solid resin transport efficiency before melting in the extruder supply unit is increased to increase the original resin density. By reducing the voids of the solid resin in the extruder to a region close to the above and then melting, it becomes difficult for the oxygen in the voids to come into contact with the molten resin. On the other hand, melt extrusion can be performed by setting the resin transport efficiency of the supply unit to 1.0 or less.
Therefore, it is considered that a cyclic olefin resin film in which the generation of foreign substances generated by the reaction between the resin and oxygen in the obtained film is suppressed can be produced without major atmospheric substitution.

Next, the method for producing the cyclic olefin resin film according to the present disclosure will be described more specifically.

<Raw material resin>
The raw material resin used in the present disclosure is not particularly limited as long as it contains a cyclic olefin resin and an elastomer, and may be selected depending on the intended use of the film to be produced.

[Cyclic olefin resin]
The cyclic olefin resin is a (co) polymer resin having a cyclic olefin structure, and examples of the polymer resin having a cyclic olefin structure include (1) a norbornene-based polymer and (2) a weight of a monocyclic cyclic olefin. Examples thereof include (3) a polymer of a cyclic conjugated diene, (4) a vinyl alicyclic hydrocarbon polymer, and hydrides of (1) to (4).

Of these, (1) norbornene-based polymers, and (2) monocyclic cyclic olefin polymers and hydrides thereof are preferable.
The norbornene-based polymer in the present disclosure is used in the sense of including a homopolymer containing a structural unit having a norbornene structure and a copolymer, and the norbornene structure may be ring-opened.
For example, as the polymer resin having a cyclic olefin structure, an additional (co) polymer cyclic polyolefin containing at least one structural unit represented by the following general formula (II) and, if necessary, the general formula (I). Examples thereof include addition copolymer cyclic polyolefins further containing at least one of the constituent units represented.
Further, as the polymer resin having a cyclic olefin structure, a ring-opening (co) polymer containing at least one cyclic structural unit represented by the general formula (III) can also be preferably used.

In the general formulas (I), (II), and (III), m represents an integer from 0 to 4. R ¹ , R ² , R ³ , R ⁴ , R ⁵ , and R ⁶ each independently represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and represent X ¹ , X ² , X ³ , Y ¹ , Y, respectively. ² and Y ³ are independently hydrogen atoms, hydrocarbon groups having 1 to 10 carbon atoms, halogen atoms, hydrocarbon groups having 1 to 10 carbon atoms substituted with halogen atoms,-(CH ₂ ) _n COOR ¹¹ ,-. (CH ₂ ) _n OCOR ¹² ,-(CH ₂ ) _n NCO,-(CH ₂ ) _n NO ₂ ,-(CH ₂ ) _n CN,-(CH ₂ ) _n CONR ¹³ R ¹⁴ ,-(CH ₂ ) _n NR ¹³ R ¹⁴ ,-(CH ₂ ) _n OZ,-(CH ₂ ) _n W, or (-CO) ₂ O composed of X ¹ and Y ¹ , X ² and Y ² , or X ³ and Y ^3. Alternatively, it represents (-CO) ₂ NR ¹⁵ . In addition, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ represent a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and Z represents a hydrocarbon group or a hydrocarbon group substituted with a halogen. W represents SiR ¹⁶ _p D _3-p (R ¹⁶ represents a hydrocarbon group having 1 to 10 carbon atoms, D represents a halogen atom, -OCOR ¹⁶ or -OR ¹⁶ and p is an integer of 0 to 3. Represents), n represents an integer from 0 to 10.

By introducing a highly polar functional group into all or part of the substituents of X ¹ , X ² , X ³ , Y ¹ , Y ² and Y ³ , the thickness direction retardation (Rth) of the optical film is increased. It can be increased to increase the expression of in-plane retardation (Re). A film having a large Re-expressing property can have a large Re value by stretching in the film forming process.
A functional group having a large partial polarity means a functional group containing two or more kinds of atoms having different electronegativity and having a dipole moment. Specific examples of the functional group having a large partial polarity include a carboxy group, a carbonyl group, an epoxy group, an ether group, a hydroxy group, an amino group, an imino group, a cyano group, an amide group, an imide group, an ester group and a sulfone group. And so on.

Norbornene-based addition (co) polymers are disclosed in JP-A No. 10-7732, JP-A-2002-504184, US Patent Publication No. US2004 / 229157A1 or International Publication No. 2004/070463A1. The norbornene-based addition (co) polymer can be obtained, for example, by addition polymerization of norbornene-based polycyclic unsaturated compounds. Further, the norbornene-based addition (co) polymer may be, if necessary, a norbornene-based polycyclic unsaturated compound and a conjugated diene such as ethylene, propylene, butene; butadiene, isoprene; a non-conjugated diene such as ethylidene norbornene; acrylonitrile. , Acrylic acid, methacrylic acid, maleic anhydride, acrylic acid ester, methacrylic acid ester, maleimide, vinyl acetate, vinyl chloride and other linear diene compounds can be added and polymerized.
As the norbornene-based addition (co) polymer, a commercially available product may be used. The norbornene-based copolymer (co) polymer is commercially available from Mitsui Chemicals, Inc. under the trade name of Apel (registered trademark), and has a different glass transition temperature (Tg), for example, APL8008T (Tg: 70 ° C.), APL6013T ( There are grades such as Tg: 125 ° C.) and APL6015T (Tg: 145 ° C.). Norbornene-based copolymers such as TOPAS 8007, 6013, and 6015 are commercially available as pellets from Polyplastics Co., Ltd. Furthermore, Appear 3000 is commercially available from Ferrania as a norbornene-based addition (co) polymer.

The hydride of the norbornene-based polymer can be obtained by addition polymerization or metathesis ring-opening polymerization of a polycyclic unsaturated compound and then hydrogenation. Regarding the hydride of the norbornene-based polymer, for example, JP-A-1-240517, JP-A-7-196736, JP-A-60-26024, JP-A-62-19801, JP-A-2003-159767 and special reference materials. It is disclosed in each publication of Kai 2004-309979, and these descriptions can be referred to in this disclosure.
As the norbornene-based polymer used in the production method according to the present disclosure, a polymer containing a cyclic structural unit represented by the above general formula (III) is preferable, and the cyclic structural unit represented by the general formula (III) is used. preferably ^{R 5} and ^{R 6} are a hydrogen atom or -CH _3, ^{X 3,} and ^{Y 3} is a hydrogen atom, is -Cl or -COOCH ₃ preferably, others groups selected appropriately.
Norbornene-based resins are commercially available from JSR Corporation under the trade name of Arton (registered trademark) G or Arton F, and from ZEON Corporation, Zeonor (registered trademark) ZF14, ZF16, and Zeonex. : Registered trademark) 250 or Zeonex 280 is commercially available under the trade name, and these can be used.

[Elastomer]
The elastomer contained in the raw material resin is not particularly limited, and examples thereof include styrene-based thermoplastic elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers. A styrene-based thermoplastic elastomer or an olefin-based elastomer is preferable, and a styrene-based thermoplastic elastomer is more preferable.
In the present disclosure, the elastomer refers to a polymer compound that exhibits rubber elasticity at room temperature (25 ° C.).

-Styrene-based thermoplastic elastomer-
The styrene-based thermoplastic elastomer is not particularly limited as long as it contains a structural unit derived from a styrene compound as a unit of the copolymer, and conventionally known ones can be used.
Examples of conventionally known styrene-based thermoplastic elastomers include SIBS (styrene-isobutylene-styrene copolymer), SEBS (styrene-ethylene-butylene-styrene copolymer), and SEPS (styrene-propylene-styrene copolymer). , SEEPS (hydrogenated styrene-isoprene butadiene-styrene copolymer), MBS (methyl methacrylate-butadiene-styrene copolymer) and the like. Further, these styrene-based thermoplastic elastomers may be hydrogenated to at least a part of the double bonds of the conjugated diene component.

The structure of the styrene-based thermoplastic elastomer is not particularly limited and may be chain-like, branched or crosslinked, but is preferably linear in order to reduce the storage elastic modulus.

The styrene content in the styrene-based thermoplastic elastomer is preferably 20 mol% to 40 mol% from the viewpoint of haze of the obtained cyclic olefin resin film.

The molecular weight of the styrene-based thermoplastic elastomer is preferably 5,000 to 500,000, more preferably 10,000 to 300,000, and 50,000 to 200,000. It is more preferable to have.

Other styrene-based elastomers include styrenes described in Japanese Patent No. 5646793, Japanese Patent Application Laid-Open No. 2004-1506048, Japanese Patent Application Laid-Open No. 2016-020412, Japanese Patent Application Laid-Open No. 2016-008772, Japanese Patent Application Laid-Open No. 2016-183303, and the like. Styrene-based elastomers are also preferably used.

-Olefin-based elastomer-
The olefin-based elastomer is not particularly limited as long as it contains a structural unit derived from an olefin compound as a unit of the copolymer, and conventionally known elastomers can be used.
For example, a copolymer of α-olefin having 2 to 20 carbon atoms such as ethylene, propylene, 1-butylene, 1-hexene and 4-methyl-pentene is preferable, and ethylene-propylene copolymer (EPR) and ethylene-propylene are preferable. -Diene copolymer (EPDM) and the like can be mentioned, and non-conjugated diene having 2 to 20 carbon atoms such as dicyclopentadiene, 1,4-hexadiene, butadiene and isoprene and α-olefin copolymer can be mentioned. .. Further, carboxy-modified NBR (acrylonitrile butadiene rubber) in which methacrylic acid is copolymerized with a butadiene-acrylonitrile copolymer can be mentioned. Specifically, ethylene / α-olefin copolymer rubber, ethylene / α-olefin / non-conjugated diene copolymer rubber, propylene / α-olefin copolymer rubber, butene / α-olefin copolymer rubber, etc. Can be mentioned.

The molecular weight of the olefin-based thermoplastic elastomer is preferably 5,000 to 500,000, more preferably 10,000 to 300,000, and 50,000 to 200,000. It is more preferable to have.

-MFR-
In the case where the glass transition temperature of the cyclic olefin resin film and Tg ℃, Tg + 50 ℃, MFR of the elastomer in the load 49N (corresponding to 5 kgf), from the viewpoint of suppressing the generation of foreign ^matter, 0.3 cm 3 / 10min or more 9 less than .0cm ³ / ^10min, is preferably 2.0 cm 3 / 10min or more 7.5 cm ³ / 10min or less.
The MFR of the elastomer can be measured, for example, by the method described in Examples. In the examples, methyl isobutyl ketone is used, but the solvent to be used may be selected according to the type of the cyclic olefin resin and the elastomer.

The ratio of the MFR of the obtained cyclic olefin resin film at Tg + 50 ° C. and load 49N to the MFR of the elastomer at Tg + 50 ° C. and load 49N is preferably 80% or more and 120% or less.
The MFR of the cyclic olefin resin film can be measured by the method described in Examples.

The glass transition temperature Tg of the cyclic olefin resin film is preferably 130 ° C. or higher and lower than 170 ° C., more preferably 140 ° C. or higher and lower than 160 ° C., and further preferably 143 ° C. or higher and lower than 155 ° C. In the present disclosure, the Tg of the film can be measured by the method in the examples described later. When the Tg is 130 ° C. or higher, the heat resistance is excellent, and it is easier to obtain sufficient manufacturing process suitability suitable for an optical film. When the Tg is lower than 170 ° C., foreign substances generated during melt film formation are further generated. Easy to suppress.

The concentration of the elastomer contained in the obtained cyclic olefin resin film is preferably 1% by mass or more and less than 20% by mass, preferably 2% by mass or more and 15% by mass or less, based on the total mass of the obtained cyclic olefin resin film. More preferably.

-How to add elastomer-
As a method of adding the elastomer to the cyclic olefin resin, both may be directly put into the extruder and melt-mixed in the extruder at the time of melt film formation, or the cyclic olefin resin and the elastomer are mixed in advance and optionally. The cyclic olefin resin and the master pellet may be put into an extruder at the time of melt-forming by forming a master pellet having an elastomer concentration of.
The cyclic olefin resin is preferably dried in advance for master pelletization. It is also preferable that the elastomer is also dried in advance. When the cyclic olefin resin or elastomer is dried, the drying method and drying conditions are not particularly limited. Examples of the drying method include a method of heating in a heating furnace at a temperature of 80 ° C. to 110 ° C., preferably around 90 ° C. for a heating time of 8 hours or more, preferably 8 hours to 12 hours. , Not limited to this. The heating temperature and heating time for drying the resin may be selected in consideration of at least one of the cyclic olefin resin or the glass transition temperature Tg of the elastomer and the melting point.
When the cyclic olefin resin and the elastomer are made into master pellets, the drying can be omitted by using, for example, a vent type extruder.
The size of the pellets in the master pellets, for example the cross-sectional area of ^{1 mm} 2 to 300 mm ^2, preferably a is 1mm~30mm length, more preferably the cross-sectional area of ^{2 mm} 2 100 mm ^2, is 1.5mm in length It is 10 mm.

Further, in the production method according to the present disclosure, various additives according to the use of the film to be produced, for example, deterioration inhibitor, ultraviolet ray inhibitor, retardation (optical anisotropy) adjuster, fine particles, peeling accelerator. , Infrared absorber and the like can be used. The additive may be a solid or an oil.
The above additive may be mixed in a master pellet containing a cyclic olefin resin and / or an elastomer, and if the additive has fluidity such as an oil, it is directly put into an extruder and the extruder is used. It may be mixed with the cyclic olefin resin and the elastomer.
As a method for mixing the additive in the master pellet, paragraphs 0043 to 0047 of International Publication No. 2017/126572 can be referred to.

In the formula for calculating the resin transport efficiency of the supply unit in the present disclosure, ρ indicates the specific gravity (g / cm ³ ) of the raw material resin, and in addition to the resin transport efficiency of the supply unit, depending on the specific gravity ρ of the resin used. You may set the parameters of.

<Supply of raw material resin to extruder>
The raw material resin is put into the hopper 12 and supplied into the cylinder 44 from the supply port 52 of the cylinder 44. The raw material resin to be charged into the hopper 12 may be pellets of the raw material resin, pellets containing the raw material resin and additives, or flaky raw material resin.
From the viewpoint of suppressing thermal oxidation of the raw material resin supplied to the cylinder 44, the oxygen concentration at the supply port 52 is preferably low, specifically 0.1% or less on a volume basis. Examples of the method of lowering the oxygen concentration in the supply port 52 include a method of supplying the raw material resin from the supply port 52 into the cylinder 44 through a vacuum hopper, a method of supplying nitrogen gas to the supply port 52 of the cylinder 44, and the like. The oxygen concentration at the supply port 52 can be measured by providing a pipe (not shown) at the supply port 52 and connecting an oxygen concentration meter (not shown).

In the formula for calculating the resin transport efficiency of the supply unit in the present disclosure, D indicates the inner diameter (mm) of the cylinder 44. The inner diameter D of the cylinder 44 is preferably 10 mm to 300 mm, more preferably 20 mm to 250 mm, from the viewpoint of performing melt extrusion while setting the resin transport efficiency of the supply unit to 0.75 or more and 1.0 or less.

The resin supplied into the cylinder 44 is gradually heated by friction due to the rotation of the screw 50 and temperature control means (not shown) arranged around the cylinder 44. From the viewpoint of supplying the raw material resin from the supply port 52 and quickly melting the raw material resin in the cylinder 44, it is preferable that the raw material resin is supplied from the supply port in a heated state.
When the glass transition temperature of the raw material resin is Tg (° C.), the temperature of the raw material resin supplied from the supply port 52 into the cylinder 44 is preferably Tg-90 ° C. or higher and Tg + 10 ° C. or lower, preferably Tg-80. It is more preferable to control the temperature to ℃ or higher and Tg -10 ℃ or lower. As a method of controlling the temperature of the raw material resin supplied from the supply port 52 into the cylinder 44 to the above-mentioned preferable range, a method of preheating the pellets to be put into the hopper, a method of using a hopper equipped with a heating means, and a hopper Apart from this, there is a method of providing a heating means near the supply port.

<Melting of raw material resin by extruder>
The raw material resin supplied from the supply port 52 into the cylinder 44 is transported toward the extrusion port 54 while being preheated in the supply unit A by the rotation of the screw 50.
In the formula for calculating the resin transport efficiency of the supply unit in the present disclosure, W indicates the flight interval (mm) of the screw 50 in the supply unit in the cylinder. The screw flight interval W is preferably 10 mm to 300 mm, more preferably 20 mm to 250 mm, from the viewpoint of performing melt extrusion while setting the resin transport efficiency of the supply unit to 0.75 or more and 1.0 or less.

Further, in the calculation formula of the resin transport efficiency of the supply unit in the present disclosure, Ψ indicates the screw flight angle (°) in the supply unit A. The screw flight angle Ψ in the supply section A is preferably 5 ° to 30 °, more preferably 10 ° to 25 °, from the viewpoint of performing melt extrusion with the supply section resin transport efficiency set to 0.75 or more and 1.0 or less. ..

Full flight, double flight, etc. can be adopted as the flight in the screw. A double flight screw is preferable from the viewpoint of promoting melt-kneading of the resin in the compression portion B. The double flight screw is a screw in which two flights are spirally arranged on the screw shaft in the compression portion B.

In the calculation formula of the resin transport efficiency of the supply unit in the present disclosure, Hf is the groove depth (mm) in the supply unit A, that is, in the radial direction of the screw shaft from the outer peripheral surface of the screw shaft in the supply unit A to the outer circumference of the screw flight. Indicates the distance (hereinafter, may be referred to as "supply section groove depth"). The groove depth Hf of the supply section is preferably 2 mm to 30 mm, more preferably 3 mm to 25 mm, from the viewpoint of performing melt extrusion with the supply section resin transport efficiency set to 0.75 or more and 1.0 or less. The groove depth of the supply section can be adjusted by adjusting the inner diameter D of the cylinder 44, the outer diameter d1 of the screw shaft in the supply section A, and the height of the screw flight 48.

The resin supplied into the cylinder 44 is gradually heated by friction caused by the rotation of the screw 50 and the like.
In the formula for calculating the resin transport efficiency of the supply unit in the present disclosure, N indicates the screw rotation speed (rpm: rotation / minute). In the method for producing a cyclic olefin resin film according to the present disclosure, since the screw is rotated in a state where the raw material resin is dense in the supply section, the screw is usually rotated at a high torque and at a relatively low speed. It will be. From this point of view, the screw rotation speed (rpm) in the manufacturing method according to the present disclosure is preferably 3 rpm to 150 rpm, more preferably 5 rpm to 100 rpm.

In the supply unit A, it is not necessary to melt all the raw material resin in the cylinder 44, but in the compression part B, all the raw material resin needs to be melted. On the other hand, in order to smoothly send the raw material resin to the compression section B side by the rotation of the screw 50 in the supply section A, there is a difference in the frictional force between the screw 50, the cylinder 44 and the resin in the supply section A and the compression section B. Is preferable.
Generally, when the cylinder 44 has a high temperature, the frictional force of the resin with respect to the cylinder 44 becomes high, and when the screw 50 has a low temperature, the frictional force of the resin with respect to the screw 50 becomes low, causing a difference in frictional force to produce the resin. The relationship is such that it can be easily sent to the compression portion B side. When the glass transition temperature of the raw material resin is Tg (° C.) and the temperature of the screw 50 is set to a temperature higher than Tg to soften the raw material resin in the supply unit A, the frictional force of the resin with respect to the screw 50 and the cylinder. The difference in the frictional force of the resin with respect to 44 becomes small, and it may be difficult to proceed to the compression portion B for melting the resin. From this point of view, it is preferable to control the temperature of the screw in the supply unit A to Tg-80 ° C or higher and Tg ° C or lower, and more preferably to control Tg-70 ° C or higher and Tg-10 ° C or lower. For example, the temperature of the screw can be controlled with high accuracy by using a screw having a structure for circulating and supplying a heat medium inside the screw shaft.

The resin heated in the supply unit A is transported to the compression unit B by the rotation of the screw, and is further heated and melted in the compression unit B. The resin melted in the compression unit B (molten resin) is further transported to the measuring unit C.
In the calculation formula of the resin transport efficiency of the supply unit in the present disclosure, the compression ratio indicates "volume per screw flight pitch in the supply unit / volume per screw flight pitch in the measurement unit". The compression ratio is calculated using the outer diameter d1 of the screw shaft of the supply unit A, the outer diameter d2 of the screw shaft of the measurement unit C, the groove depth Hf of the supply unit A, and the groove depth Hm of the measurement unit C. The screw.

If the compression ratio is too small, the raw material resin is not sufficiently melt-kneaded, undissolved portions are generated, undissolved foreign substances are likely to remain on the cyclic olefin resin film after production, and bubbles are likely to be mixed. As a result, the strength of the cyclic olefin resin film may be lowered, or the film may be easily broken when stretched, and the orientation may not be sufficiently increased. On the other hand, if the compression ratio is too large, the shear stress applied to the raw material resin becomes too large and the resin tends to deteriorate due to heat generation, so that the cyclic olefin resin film after production may easily become yellowish. Further, if the shear stress applied to the raw material resin becomes too large, the molecules may be cut in the raw material resin, the molecular weight may decrease, and the mechanical strength of the film may decrease.
The compression ratio is preferably 1.5 to 4.0, more preferably 2.0 to 3.5, from the above viewpoint and the viewpoint of performing melt extrusion with the resin transport efficiency of the supply unit set to 0.75 or more and 1.0 or less. preferable. The compression ratio is adjusted by adjusting at least one of the inner diameter D of the cylinder 44, the outer diameters d1 and d2 of the screw shaft in the supply part and the measuring part, the flight interval W of the screw 50, and the flight angle Ψ. Can be done.

In the formula for calculating the resin transport efficiency of the supply unit in the present disclosure, the L / D is preferably 20 to 70. L / D is the ratio of the cylinder length L to the cylinder inner diameter D.
The extrusion temperature is preferably set to 200 ° C. to 300 ° C.
The set temperature in the extruder may be the same temperature in the entire region, or may have a different temperature distribution depending on the region. It is preferable that the temperature distribution differs depending on the region, and it is more preferable that the temperature of the supply unit A described above is higher than the temperature of the compression unit B in the extruder.

If the L / D is too small, insufficient melting or kneading of the raw material resin in the extruder is likely to occur, and as in the case of a small compression ratio, undissolved foreign matter may be easily generated in the cyclic olefin resin film after production. There is. On the contrary, if the L / D is too large, the residence time of the raw material resin in the extruder becomes too long, and the resin is likely to deteriorate. Further, if the residence time is long, the raw material resin may be cleaved with molecules, or the molecular weight of the raw material resin may be lowered due to the cleaving of the molecules, and the mechanical strength of the cyclic olefin resin film may be lowered.
From this point of view, the L / D is preferably in the range of 20 to 70, more preferably in the range of 22 to 60, and even more preferably in the range of 24 to 50.

The molten resin is extruded from the extrusion port 54 of the cylinder 44 via the measuring unit C. The measuring unit C measures the molten resin and stabilizes the amount extruded from the extrusion port 54.

The molten resin extruded from the extruder 14 is transported toward the die 20 through the pipe 40, and it is preferable to perform so-called breaker plate type filtration in which a filter filter medium is provided at the outlet of the extruder 14. Further, it is preferable that the molten resin extruded from the extruder 14 is transported to the die 20 via the gear pump 16 and the filter 18. The molten resin is sometimes referred to as "melt".

[Gear pump]
In order to improve the thickness accuracy of the film, it is important to keep the fluctuation of the discharge amount of the molten resin extruded from the extruder 14 low. From the viewpoint of further reducing the fluctuation of the discharge amount, it is preferable to provide a gear pump 16 between the extruder 14 and the die 20 to supply a constant amount of molten resin from the gear pump 16.
The gear pump is housed in a state where a pair of gears consisting of a drive gear and a driven gear are meshed with each other, and by driving the drive gear to mesh and rotate both gears, the gear pump is in a molten state from a suction port formed in the housing. The resin is sucked into the cavity, and a certain amount of resin is discharged from the discharge port also formed in the housing. Even if the resin pressure at the tip of the extruder fluctuates slightly, by using the gear pump, the fluctuation is absorbed, the fluctuation of 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 of the die portion within ± 1%.

In order to improve the fixed quantity supply performance by the gear pump, a method of changing the rotation speed of the screw to suppress the fluctuation of the pressure applied to the raw material resin in front of the gear pump can also be used. A high-precision gear pump using three or more gears is also effective in suppressing pressure fluctuations.

〔filter〕
In order to prevent foreign matter from entering with higher accuracy, it is preferable to provide the filter 18 after passing through the gear pump 16. As the filter 18, a filtration device incorporating a so-called leaf type disc filter is preferable. The raw material resin discharged from the extruder may be filtered by providing one filtration unit, or may be a multi-stage filtration by providing a plurality of filtration units. It is preferable that the filtration accuracy of the filter medium is high. However, the filtration accuracy is preferably 15 μm to 3 μm, more preferably 10 μm to 3 μm, from the viewpoint of considering the pressure resistance of the filter medium and suppressing the increase in the filter pressure due to clogging of the filter medium. In particular, when using a leaf-type disc filter device that finally filters foreign matter, it is preferable to use a filter medium with high filtration accuracy in terms of quality, and in order to ensure the pressure resistance and the suitability of the filter life, the filter unit It is possible to adjust the pressure resistance, the life of the filter, etc. by the number of filter media loaded in the filter medium.

As the type of filter medium used for the filter, it is preferable to use a filter medium formed of a steel material from the viewpoint of being used under high temperature and high pressure. Among the steel materials forming the filter medium, stainless steel, steel and the like are particularly preferable, and stainless steel is particularly preferable from the viewpoint of corrosion.
As the structure of the filter medium, in addition to the filter medium formed by knitting a wire rod, for example, a sintered filter medium formed by sintering metal filaments or metal powder can be used, and the sintered filter medium can be used from the viewpoint of filtration accuracy and filter life. Is preferable.

<Melting extrusion with die>
The molten resin (melt) continuously sent to the die 20 through the extruder 14, the gear pump 16 and the filter 18 is melt-extruded from the die 20 into a film.

As the die 20, in addition to the generally used T die, a fishtail die or a hanger coat die may be used.
A static mixer for improving the uniformity of the resin temperature may be inserted immediately before the die 20.
The slit spacing (lip clearance) of the die 20 is generally preferably 1.0 to 5.0 times, more preferably 1.2 to 3 times, still more preferably 1.3 to 2 times the film thickness. .. When the lip clearance is 1.0 times or more the film thickness, it is easy to obtain a film having a good surface shape by film formation. Further, if the lip clearance is 5.0 times or less the film thickness, the film thickness accuracy can be improved.

The die is one of the facilities that influences the thickness accuracy of the film, and it is preferable that the die can control the thickness with high accuracy. Usually, the installation interval of the thickness adjusting equipment for adjusting the thickness of the film extruded from the die in the width direction of the die can be selected in the range of 40 mm to 50 mm. From the viewpoint that the narrower the installation interval of the thickness adjusting equipment is, the more detailed the thickness can be controlled, the fine film thickness can be installed with the installation interval preferably 35 mm or less, more preferably 25 mm or less. It is preferable to use an adjustable type die.
Further, in order to further improve the uniformity of the film, it is preferable to adjust the conditions so that the temperature unevenness of the die and the flow velocity unevenness in the width direction can be reduced as much as possible. It is also effective to reduce the thickness fluctuation of long-term continuous production by using an automatic thickness adjustment die that measures the thickness of the film downstream, calculates the thickness deviation, and feeds back the result to the thickness adjustment of the die.

A single-layer film forming apparatus having a low equipment cost is generally used for film production. However, if necessary, it is also possible to produce a film having two or more types of structures by using a multi-layer film forming apparatus in which a functional layer is provided on an outer layer of a cylinder 44. When a multilayer film is formed by using a multilayer film forming apparatus, it is generally preferable to laminate a functional layer thinner than the resin film as a base material on the surface of the cyclic olefin resin film as a surface layer. However, the thickness ratio of each layer in the multilayer structure is not particularly limited.

In the formula for calculating the resin transport efficiency of the supply unit in the present disclosure, Q indicates the extrusion amount (kg / h) of the molten resin. The extrusion amount (kg / h) of the molten resin depends on the supply amount (kg / h) of the raw material resin to the supply port of the extruder, and is regarded as the extrusion amount (kg / h) from the extrusion port of the extruder. You can also. The extrusion amount Q of the molten resin depends on the capacity of the cylinder of the extruder, the type of die, etc., but from the viewpoint of performing melt extrusion with the resin transport efficiency of the supply section set to 0.75 or more and 1.0 or less, the molten resin is extruded. The extrusion amount of the above is preferably 0.5 kg / h to 1800 kg / h, more preferably 1 kg / h to 900 kg / h.

<Cast>
Under the above conditions, the molten resin extruded into a film from the die is cooled and solidified on a casting roll to obtain a cyclic olefin resin film. By heating the melt-extruded film with a far-infrared heater before the molten resin comes into contact with the casting roll, a leveling effect is exhibited on the drum, and the surface of the melt-extruded film becomes more uniform. The film thickness distribution of the obtained film can be reduced, and the occurrence of die streaks can be suppressed.

To improve the adhesion between the casting roll and the melt-extruded sheet by using methods such as the electrostatic application method, the air knife method, the air chamber method, and the vacuum nozzle method for the melt-extruded molten resin on the casting roll. Is preferable.
It is also preferable that the improvement of the adhesiveness is performed by narrowing the pressure in the step of narrowing the pressure described later.

The thickness of the unstretched film produced by the production method according to the present disclosure may be determined according to the intended use, but when used as an optical film, it is preferably 20 μm to 250 μm from the viewpoint of mechanical strength and light transmission. It is more preferably 25 μm to 200 μm, and even more preferably 30 μm to 180 μm.

[Process of narrowing pressure]
In the method for producing a cyclic olefin resin film according to the present disclosure, from the viewpoint of surface smoothness of the obtained cyclic olefin film, the molten resin obtained by the step of melt-extruding into a film is formed into a gap between a pair of smooth rolls. It is preferable to further include a step of introducing into the formed narrow pressure portion and narrowing the pressure.
The step of narrowing the pressure can be performed by using the above-mentioned casting roll and touch roll as a pair of smooth rolls (touch roll method).
In the touch roll method, the high-temperature molten resin discharged from the die is sandwiched between the casting roll and the touch roll arranged on the casting roll to cool and shape the film surface, that is, to smooth the film surface. Is a way to do that. As the touch roll used in the present disclosure, a roll having elasticity is preferable to a roll having high rigidity as usual.

The temperature of the touch roll is preferably more than the glass transition temperature of the cyclic olefin resin film Tg-10 ° C. and Tg + 30 ° C. or lower, more preferably Tg-7 ° C. or higher and Tg + 20 ° C. or lower, and further preferably Tg-5 ° C. or higher and Tg + 10 ° C. or lower. is there. When a plurality of touch rolls are used, it is preferable to adjust each touch roll to the above temperature range. Further, it is preferable to adjust the temperature of the casting roll to the same temperature range as that of the touch roll described above.

Specific examples of the touch roll include the touch rolls described in JP-A-11-314263 and JP-A-11-235747, and the touch rolls described herein are used in the manufacturing method according to the present disclosure. it can.

Further, it is more preferable to slowly cool the discharged resin by using a plurality of casting rolls. The number of casting rolls used for slow cooling is not particularly limited, and is appropriately selected according to the purpose. For example, a method using three casting rolls for slow cooling of the resin can be mentioned, but the present invention is not limited to this.
When a plurality of casting rolls are used for cooling the discharged resin, it is preferable that the touch rolls are arranged at positions where they touch the first casting roll on the most upstream side (closer to the die).

The diameter of the casting roll is preferably 50 mm to 5000 mm, more preferably 100 mm to 2000 mm, and even more preferably 150 mm to 1000 mm. When a plurality of casting rolls are used, it is preferable that all casting rolls are in the above diameter range.
When a plurality of casting rolls are used, the distance between adjacent casting rolls is preferably 0.3 mm to 300 mm, more preferably 1 mm to 100 mm, and further preferably 3 mm to 30 mm.
Further, the line speed on the most upstream side of the casting roll is preferably 20 m / min or more and 70 m / min or less.

<winding>
After the cooled film (unstretched film) is peeled off from the casting roll, the film is wound through a nip roll (not shown).

It is also preferable to trim both ends before winding. Trimming can be performed by a known method. As the trimming cutter used for trimming, any type of cutter such as a rotary cutter, a shear blade, or a knife may be used. Examples of the material of the cutter include carbon steel and stainless steel, and any material of the cutter may be used. In general, it is preferable to use a trimming cutter having a 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 thickening processing (knurling treatment) on one end or both ends of the cyclic olefin resin film. The height of the unevenness due to the thickening process is preferably 1 μm to 200 μm, more preferably 10 μm to 150 μm, and further preferably 20 μm to 100 μm. The thickening process may be a shape that is convex on both sides or a shape that is convex on one side. The width of the thickening process is preferably 1 mm to 50 mm, more preferably 3 mm to 30 mm, and further preferably 5 mm to 20 mm. The thickening process can be carried out at room temperature to 300 ° C.

When winding, it is preferable to attach a protective film to at least one side from the viewpoint of scratch prevention. The thickness of the protective film is preferably 5 μm to 200 μm, preferably 10 μm to 150 μm, and preferably 15 μm to 100 μm. The material of the protective film is not particularly limited. Examples of the material of the protective film include polyethylene, polyester, polypropylene and the like.

<Stretching>
The formed film can be stretched according to the purpose.
In the case of stretching, the film-formed film may be subjected to online stretching in which the film is stretched as it is, or may be subjected to offline stretching in which the film is once wound and then sent out again to be stretched.

The stretching direction may be lateral stretching in the width direction of the film-formed film, longitudinal stretching in the film-forming direction of the film-formed film, or both transverse stretching and longitudinal stretching.
Further, the relaxation treatment described later may be performed in combination with stretching. These can be carried out, for example, in the following combinations.

As the stretching, it is preferable to carry out a combination of transverse stretching and longitudinal stretching. When the transverse stretching and the longitudinal stretching are performed, biaxial simultaneous stretching may be performed, or sequential stretching may be performed. Of these, it is more preferable to first perform longitudinal stretching and then lateral stretching to perform sequential stretching.

<Mitigation processing>
The dimensional stability of the resin film can be improved by performing a relaxation treatment after stretching the obtained resin film. The relaxation treatment is preferably a heat relaxation treatment in which at least one of the vertical and horizontal dimensions of the stretched film is relaxed by, for example, about 1% to 8%, and then heat-fixed. The temperature in the heat relaxation treatment is appropriately selected depending on the type of the cyclic olefin resin used for the cyclic olefin resin film, but is generally preferably 130 ° C. to 240 ° C.
The heat relaxation is preferably performed by either or both of the longitudinal stretching and the transverse stretching, and more preferably after the transverse stretching. The relaxation treatment may be continuously performed online after stretching the cyclic olefin resin film, or may be performed offline with respect to the cyclic olefin resin film wound after stretching.

According to the production method according to the present disclosure, it is possible to produce a cyclic olefin resin film which suppresses the generation of foreign substances and has excellent impact strength with high productivity.
The cyclic olefin resin film produced by the production method according to the present disclosure is used as an optical film by itself because it suppresses the generation of foreign substances, has good optical characteristics, and has excellent heat resistance and impact strength. May be good. Further, it may be used in combination with a polarizing plate, or may be used by providing a functional layer such as a liquid crystal layer, a layer having a controlled refractive index (low reflection layer), or a hard coat layer, and the obtained cyclic olefin resin may be used. The application range of the film is wide.

(Cyclic olefin resin film)
The cyclic olefin resin film according to the present disclosure contains a cyclic olefin resin and an elastomer, and has a maximum diameter of 30 μm or more and a maximum number of foreign substances of 0.3 pieces / cm ² or less per 100 μm thickness of the cyclic olefin resin film. When the number of foreign substances having the longest diameter of 5 μm or more and less than 30 μm is 100 pieces / cm ² or less and the glass transition temperature of the cyclic olefin resin film is Tg ° C., the MFR of the elastomer at Tg + 50 ° C. and a load of 49 N is 0. 3cm ³ / 10min more than 9.0cm is less than ³ / 10min.
The cyclic olefin resin film according to the present disclosure can be produced by the production method according to the present disclosure, and is preferably produced by the production method according to the present disclosure.

The physical properties of the cyclic olefin resin film according to the present disclosure, such as Tg and MFR, are synonymous with the contents described as the physical properties of the cyclic olefin resin film obtained by the above-mentioned production method according to the present disclosure, and the preferred embodiments are also the same.
The type of cyclic olefin resin and elastomer contained in the cyclic olefin resin film according to the present disclosure, physical properties such as MFR, and the relationship between the above physical properties are synonymous with the cyclic olefin resin and elastomer in the production method according to the present disclosure, and are preferred embodiments. Is the same.

-Elastomer content-
The content of the elastomer in the cyclic olefin resin film according to the present disclosure is preferably 1% by mass or more and less than 20% by mass, and 2% by mass or more and 15% by mass or less, based on the total mass of the cyclic olefin resin film. Is more preferable.
The above content can be measured by the method in the examples described later.

-Average particle size-
The average particle size of the elastomer in the cyclic olefin resin film according to the present disclosure is preferably 100 nm or more and less than 1,000 nm, and more preferably 100 nm or more and less than 500 nm.
The average particle size can be measured by the method in the examples described later.

[Foreign matter]
The cyclic olefin resin film according to the present disclosure has a thickness of 100 μm, a maximum number of foreign substances having a maximum diameter of 30 μm or more is 0.3 pieces / cm ² or less, and a maximum length of 5 μm or more and less than 30 μm is 100 pieces /. It is cm ² or less.
The number of foreign substances having the longest diameter of 30 μm or more is preferably 0.2 pieces / cm ² or less, and more preferably 0.1 pieces / cm ² or less.
The number of foreign substances having the longest diameter of 5 μm or more and less than 30 μm is preferably 50 pieces / cm ² or less, and more preferably 30 pieces / cm ² or less.
The number and size of foreign substances contained in the cyclic olefin resin film according to the present disclosure can be measured by the method in Examples described later.

(Composite film)
The composite film according to the present disclosure includes a cyclic olefin resin film according to the present disclosure.
The composite film according to the present disclosure may further have a polarizing plate, and further has a functional layer such as a liquid crystal layer, a layer having a controlled refractive index (for example, a low reflection layer), and a hard coat layer. May be good.
The composite film according to the present disclosure may be produced, for example, by using the above-mentioned multilayer film forming apparatus, or may be produced by another known method.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded. Unless otherwise specified, "parts" are based on mass.

<Manufacturing method>
In Examples and Comparative Examples, cyclic olefin resin films were basically produced according to the following procedure. However, in each example, the screw flight interval W of the screw, the groove depth Hf of the supply section, the cylinder inner diameter D of the extruder, the compression ratio, and the Q / N are changed as shown in the attached table to change the resin transport efficiency of the supply section. Was adjusted.
As Q and N of Comparative Example 3 in Table 1, the set values of the apparatus are shown. In reality, it could not be extruded due to resin clogging.
Further, as the density ρ of the raw material resin used for calculating the resin transport efficiency of the supply section, the value of "specific gravity of the entire film" shown in Table 2 was used.

[Master pellet manufacturing]
The cyclic olefin resin described in the column of matrix material in Table 2 was pre-dried at 100 ° C. for 5 hours.
The elastomers listed in the Matrix Material column of Table 2 were pre-dried at 80 ° C. for 12 hours.
The cyclic olefin resin described in the column of matrix material in Table 2 and the pellet of the elastomer described in the column of matrix material in Table 2 were charged into the extruder at a ratio of 30% by mass of the elastomer, and at 285 ° C. Melt extrusion was performed to obtain master pellets.

[Film formation]
The cyclic olefin resin and the master pellet obtained by the above method were pre-dried at 100 ° C. for 5 hours.
After the pre-drying, the cyclic olefin resin and the master pellet were put into a hopper provided in the extruder so that the elastomer concentration in the obtained cyclic olefin resin film was the concentration shown in Table 1, and melted at 285 ° C. by the extruder. .. The above temperature is the temperature of the cylinder after the compression part.
The molten resin (melt) extruded from the extruder and transported to the gear pump through the pipe was further sent out from the gear pump and filtered by a leaf type disc filter having a filtration accuracy of 5 μm.
After filtration, melt (molten resin) is extruded onto a casting roll 1 (CR1) set at 137 ° C from a coat hanger die with a slit interval of 1.0 mm and 285 ° C, and a touch roll (metal, set at 133 ° C) is extruded onto the casting roll 1 (CR1). ) Was brought into contact. Then, after passing through the casting roll 2 (CR2) and the casting roll 3 (CR3), a film having an arbitrary thickness was obtained.
The above touch roll was not used for the example in which "None" was described in the "Presence / absence of touch roll" column in Table 1.

<Measurement, evaluation>
The following measurements and evaluations were carried out on the cyclic olefin resin film obtained above.

[Number of foreign substances]
The number of foreign substances per 100 μm thickness of the obtained film was measured in a range of 10 cm × 10 cm at the center of the film using a differential interference microscope (200 times) manufactured by Nikon Corporation. In the measurement, the number of foreign substances having a maximum diameter of 30 μm or more and the number of foreign substances having a maximum diameter of 5 μm or more and less than 30 μm were recorded, and the value obtained by dividing 100 μm by the film thickness was multiplied by the recorded number of foreign substances. , The number of foreign substances.
The measurement results are shown in Table 2.

[Elastomer MFR]
The elastomer component was extracted from the obtained film by the following method, and the MFR (melt flow rate) of the elastomer was measured. The value of MFR was based on JIS K 7210 (2014), the temperature was Tg + 50 ° C. measured by the following method, and the load was 49N (5 kgf).
The elastomer component was extracted from the film by the following method. A plurality of 10 cm × 10 cm central portions of the obtained film are sampled and immersed in methyl isobutyl ketone (MIBK), which is a solvent in which the cyclic olefin resin is dissolved but the elastomer is not dissolved. At this time, the amount of the solvent is 1,000 times or more the amount of the film to be treated. The elastomer that remains undissolved and precipitates is collected by filtration and dried at room temperature to remove the solvent component to obtain a simple elastomer component.

[MFR of cyclic olefin resin film]
The MFR (melt flow rate) of the obtained cyclic olefin resin film was measured without extracting the elastomer component by the above method. The value of MFR was based on JIS K 7210 (2014), the temperature was Tg + 50 ° C. measured by the following method, and the load was 49N (5 kgf).

[Glass transition temperature Tg]
The center portion of the obtained film was sampled, and the glass transition temperature was measured by DSC (differential scanning calorimetry, DSC-60A manufactured by Shimadzu Corporation).

[Concentration of elastomer]
The center portion of the obtained film was sampled at 10 cm × 10 cm, and its mass was measured. Then, the elastomer component was extracted from the sampled film by the above method, and the mass thereof was measured. The mass of the elastomer was divided by the mass of the film and multiplied by 100 to define the concentration of the elastomer. The measurement results are shown in Table 2.

[Average particle size of elastomer]
A scanning electron microscope was used to observe the elastomer dispersed in the film. At 10 different sites of the sample, a fractured surface parallel to the width direction of the film (direction perpendicular to the film transport direction on the film surface) and perpendicular to the film surface was observed. The observation was carried out at an appropriate magnification of 100 to 10,000 times, and an image was taken so that the dispersed state of the elastomer particles in the width of the entire thickness of the film could be confirmed. For 200 randomly selected elastomer particles, the outer circumference of each particle is traced, the circle equivalent diameter of the particles is measured from these trace images with an image analyzer, the arithmetic mean value is obtained, and this is the average grain of the elastomer. Defined as diameter. The circle-equivalent diameter means the diameter of a circle equal to the area of the trace image. The measurement results are shown in Table 2.

[Surface Roughness Ra]
The surface roughness Ra of the film can be measured using a stylus type roughness meter according to JIS B 0601 (2013). Ra was measured at five randomly selected points within the center of the film, 10 cm × 10 cm, and was calculated as an arithmetic mean value. The obtained Ra was evaluated based on the following indexes. It can be said that the smaller the Ra value, the better the surface smoothness of the cyclic olefin resin. The evaluation results are shown in Table 2.
A: Ra is 5 nm or more and less than 15 nm B: Ra is 15 nm or more and less than 20 nm C: Ra is 20 nm or more and less than 50 nm D: Ra is 50 nm or more

[Impact strength]
The impact strength of the obtained film was measured using a film impact tester (manufactured by Toyo Seiki Seisakusho Co., Ltd.). The measured impact strength was evaluated based on the following indexes. The evaluation results are shown in Table 2.
A: Impact strength is 1.5N ・ m or more B: Impact strength is 1.2N ・ m or more and less than 1.5N ・ m C: Impact strength is 0.8N ・ m or more and less than 1.2N ・ m D: Impact strength is less than 0.8 Nm

Details of the abbreviations listed in Table 2 are as follows.
COP: Cyclic olefin resin, ARTON (registered trademark) manufactured by JSR Corporation, glass transition temperature Tg: 151 ° C.
SEBS: Styrene-ethylene-butylene-styrene copolymer, Asahi Kasei Tough Tech MBS: Methyl methacrylate-butadiene-styrene copolymer, Denka TH polymer TPO: Olefin elastomer, JSR EXCELINK

As shown in Table 2, a cyclic olefin resin and a raw material resin containing an elastomer are melt-extruded under the condition that the supply resin transport efficiency satisfies 0.75 or more and 1.0 or less, and the glass of the cyclic olefin resin film is formed. transition temperature Tg + 50 ° C., in each example the melt flow rate of the elastomer is less than 0.3 cm ³ / 10min or more 9.0 cm ³ / 10min in load 49N, the occurrence of the foreign matter is suppressed, excellent surface smoothness, Moreover, a cyclic olefin resin film having excellent impact strength was obtained.

(Explanation of sign)
10 Membrane-making device 12 Hopper 14 Extruder 16 Gear pump 18 Filter 20 Die 22, 24, 26 Cooling roll 28 Contact roll 40 Piping 44 Cylinder 46 Screw shaft 48 Flight (screw flight)
50 Screw 52 Supply port 54 Extrusion port 100 Raw material resin Hf Groove depth Hm of supply part A Groove depth d1 of measurement part C Outer diameter of screw shaft of supply part A d2 Outer diameter A of screw shaft of measurement part C Supply part B Compressing part C Measuring part D Cylinder inner diameter L Cylinder length W Screw flight interval at the supply part Ψ Screw flight angle at the supply part

The disclosure of Japanese patent application 2018-029132, filed February 21, 2018, is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described herein are to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. Incorporated herein by reference.

Claims (12)

A cylinder having a supply port for supplying a cyclic olefin resin and a raw material resin containing an elastomer and an extrusion port for extruding a molten resin obtained by melting the raw material resin.
Has a screw shaft and a spirally arranged flight around the screw shaft,
With a screw that rotates in the cylinder,
An extruder having a supply unit, a compression unit, and a measuring unit in this order from the side of the supply port along the screw shaft is used in the cylinder.
The raw material resin is supplied and melted under the condition that the supply unit resin transport efficiency calculated by the following formula satisfies 0.75 ≤ supply unit resin transport efficiency ≤ 1.0.
It has a step of melt-extruding the molten resin extruded from the extrusion port from a die into a film.
The glass transition temperature of the resulting cyclic olefin resin film when the Tg ℃, Tg + 50 ℃, the melt flow rate of said elastomeric in load 49N is less than 0.3 cm ³ / 10min or more 9.0 cm ³ / 10min,
A method for producing a cyclic olefin resin film.


W: Screw flight interval (mm) in the supply section
Hf: Groove depth (mm) in the supply section
D: Cylinder inner diameter (mm)
Ψ: Screw flight angle (°) at the supply section
Q: Extruded amount of molten resin (kg / h)
ρ: Specific gravity of raw material resin (g / cm ³ )
N: Screw rotation speed per minute (rpm)
Compression ratio: Volume per screw flight pitch in the supply section / Volume per screw flight pitch in the weighing section The production of the cyclic olefin resin film according to claim 1, wherein the concentration of the elastomer contained in the obtained cyclic olefin resin film is 1% by mass or more and less than 20% by mass with respect to the total mass of the obtained cyclic olefin resin film. Method. The method for producing a cyclic olefin resin film according to claim 1 or 2, wherein the elastomer is a styrene-based thermoplastic elastomer. Claims 1 to claim that the ratio of the melt flow rate of the obtained cyclic olefin resin film at Tg + 50 ° C. and a load of 49 N to the melt flow rate of the elastomer at the Tg + 50 ° C. and a load of 49 N is 80% or more and 120% or less. Item 3. The method for producing a cyclic olefin resin film according to any one of Items 3. Any of claims 1 to 4, further comprising a step of introducing a molten resin obtained by a step of melt-extruding into a film into a narrowing portion formed in a gap between a pair of smooth rolls and narrowing the pressure. The method for producing a cyclic olefin resin film according to claim 1. Cyclic olefin resin film
Contains cyclic olefin resins and elastomers
The number of foreign substances having a maximum diameter of 30 μm or more is 0.3 pieces / cm ² or less and the number of foreign substances having a maximum diameter of 5 μm or more and less than 30 μm is 100 pieces / cm ² or less per 100 μm of the thickness of the cyclic olefin resin film. Yes,
The glass transition temperature of the cyclic olefin resin film when the Tg ℃, Tg + 50 ℃, the melt flow rate of said elastomeric in load 49N is less than 0.3 cm ³ / 10min or more 9.0 cm ³ / 10min,
Cyclic olefin resin film. The cyclic olefin resin film according to claim 6, wherein the content of the elastomer is 1% by mass or more and less than 20% by mass with respect to the total mass of the cyclic olefin resin film. The cyclic olefin resin film according to claim 6 or 7, wherein the elastomer is a styrene-based thermoplastic elastomer. Claims 6 to 8 that the ratio of the melt flow rate of the cyclic olefin resin film at Tg + 50 ° C. and a load of 49 N to the melt flow rate of the elastomer at the Tg + 50 ° C. and a load of 49 N is 80% or more and 120% or less. The cyclic olefin resin film according to any one of the above. The cyclic olefin resin film according to any one of claims 6 to 9, wherein the average particle size of the elastomer is 100 nm or more and less than 1000 nm. The cyclic olefin resin film according to any one of claims 6 to 10, wherein the Tg ° C. is 130 ° C. or higher and lower than 170 ° C. A composite film having the cyclic olefin resin film according to any one of claims 6 to 11.