JP5810679B2 - Film production method - Google Patents

Description

  The present invention relates to a method for producing a film, and more specifically, using a hydrogenated dicyclopentadiene ring-opened polymer having crystallinity as a raw material resin, particularly capable of producing a film excellent in smoothness and heat resistance. Regarding the method.

  For example, dicyclopentadiene ring-opening polymer hydride as described in Patent Document 1 is a kind of so-called cycloolefin polymer, and is excellent in transparency, low birefringence, molding processability, and the like. It is used as a material applicable to various uses.

  As is also the case described in Patent Document 1, a ring-opening polymer hydride of dicyclopentadiene is often obtained as an amorphous polymer having no melting point. However, amorphous ring-opening polymer hydrides of dicyclopentadiene may have insufficient heat resistance or chemical resistance depending on the application. Thus, as a technique for improving these performances, it has been proposed to impart crystallinity to a dicyclopentadiene ring-opening polymer hydride by using a specific ring-opening polymerization catalyst.

  For example, Patent Document 2 gives crystallinity to dicyclopentadiene ring-opening polymer hydride by ring-opening polymerization of dicyclopentadiene using a specific catalyst, and using this to form a film, It is disclosed that a film excellent in heat resistance and chemical resistance can be obtained. The dicyclopentadiene ring-opening polymer hydride as described in Patent Document 2 has crystallinity and imparts excellent heat resistance to the film based on the crystallinity. Compared to general crystalline resins such as polypropylene, it has a property that the crystallization rate is low. Therefore, in Patent Document 2, as a method for expressing the crystallinity of the film more strongly, after the film is melt-molded, when it is cooled, the temperature is equal to or higher than the glass transition temperature of the dicyclopentadiene ring-opening polymer hydride that is a raw material resin. For a relatively long time (annealing treatment) and for stretching the film.

Japanese Patent Laid-Open No. 11-124429 Japanese Patent Laid-Open No. 2002-194067

  However, according to the study by the present inventors, the film of dicyclopentadiene ring-opening polymer hydride has a strong tendency to cause unevenness in the film by annealing compared to other crystalline resin films. It has become clear that there is a problem that the smoothness and transparency of the film obtained through the process are inferior. Further, in the crystallization by the stretching treatment, there is a risk that streaks along the stretching direction may occur in the film, and there is a problem that it is difficult to control the thickness of the film.

  Therefore, the present invention provides a method for producing a film, which can give a film particularly excellent in smoothness and heat resistance when producing a film using a dicyclopentadiene ring-opened polymer hydride having crystallinity as a raw material resin. The purpose is to do.

  As a result of intensive studies to achieve the above object, the inventors of the present invention held the film by a specific method, put the film in a tensioned state, and subjected the film in this state to an annealing treatment, whereby the film It was found that the film can be crystallized while maintaining the smoothness of the film. And it discovered that the heat resistance of a film etc. could be improved significantly by this. The present invention has been completed based on these findings.

  Thus, according to the present invention, the raw material resin which is a dicyclopentadiene ring-opening polymer hydride having crystallinity is formed into a rectangular film by a melt molding method, and the four sides of the obtained film are retained. Thus, the film is brought into a tensioned state, and the film is crystallized by placing the film under a temperature condition not lower than the glass transition temperature and not higher than the melting point of the raw material resin.

  In the film manufacturing method, in the step of crystallizing the film, when the four sides of the film are held, the two opposing sides can be held by the tenter device.

  According to this invention, the film which uses the dicyclopentadiene ring-opening polymer hydride which has the crystallinity which is excellent in smoothness and heat resistance especially as raw material resin can be manufactured.

  In the film production method of the present invention, as a first step, a raw material resin which is a dicyclopentadiene ring-opening polymer hydride having crystallinity is formed into a rectangular film by a melt molding method.

  The crystallized dicyclopentadiene ring-opening polymer hydride used as a raw material resin undergoes ring-opening polymerization using dicyclopentadiene as the main monomer, and the carbon-carbon double bond present in the resulting ring-opening polymer Can be obtained by hydrogenation (hydrogenation) of at least a part thereof. However, in carrying out the ring-opening polymerization, it is necessary to select a ring-opening polymerization catalyst capable of imparting crystallinity to the finally obtained dicyclopentadiene ring-opening polymer hydride.

  The crystallized dicyclopentadiene ring-opening polymer hydride used as the raw material resin may be any one having crystallinity, that is, any one having a melting point exceeding normal temperature (23 ° C.). However, from the viewpoint of particularly improving the heat resistance of the target film, the film preferably has a melting point of 150 ° C. or higher, and preferably has a melting point of 200 to 300 ° C. The glass transition temperature of the dicyclopentadiene ring-opened polymer hydride is not particularly limited, but is preferably in the range of 85 to 110 ° C. The melting point and glass transition temperature of the dicyclopentadiene ring-opened polymer hydride are measured by differential scanning calorimetry.

The presence or absence of stereoregularity of the dicyclopentadiene ring-opening polymer hydride is not particularly limited as long as the dicyclopentadiene ring-opening polymer hydride has crystallinity. From the viewpoint of making the heat resistance particularly good, it is preferably one having stereoregularity (that is, other than an atactic structure), and particularly preferably one having a syndiotactic structure. More specifically, the ratio of racemo dyad to the repeating unit obtained by ring-opening polymerization of dicyclopentadiene and then hydrogenating is preferably 55% or more, more preferably 60% or more. It is preferably 65% or more. The higher the ratio of racemo dyad, that is, the higher the syndiotactic stereoregularity, the more dicyclopentadiene ring-opening polymer hydride having a higher melting point. The ratio of racemo dyad can be measured and quantified by ¹³ C-NMR spectrum analysis. As a specific quantitative method, ortho-dichlorobenzene-d4 is used as a solvent and an inverse-gated decoupling method is applied at 150 ° C. to perform 13C-NMR measurement, and the 127.5 ppm peak of orthodichlorobenzene-d4 is used as a reference. An example of the shift is a method of determining the ratio of the racemo dyad from the intensity ratio of the 43.35 ppm signal derived from the meso dyad and the 43.43 ppm signal derived from the racemo dyad.

  Dicyclopentadiene used as a monomer to obtain a dicyclopentadiene ring-opening polymer hydride has endo and exo stereoisomers, both of which can be used as monomers. One isomer may be used alone, or a mixture of isomers in which an endo isomer and an exo isomer are present in an arbitrary ratio can be used. However, from the viewpoint of increasing the crystallinity of the dicyclopentadiene ring-opening polymer hydride and making the heat resistance particularly good, it is preferable to increase the ratio of one stereoisomer, for example, an endo or exo The body ratio is preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. In addition, it is preferable that the stereoisomer which makes a ratio high is an end body from a viewpoint of synthetic | combination ease.

  The monomer used to obtain the dicyclopentadiene ring-opened polymer hydride is dicyclopentadiene as the main monomer, and the finally obtained dicyclopentadiene ring-opened polymer hydride has crystallinity. As long as it becomes a thing, the compound which can be copolymerized with dicyclopentadiene may be included. Examples of such compounds include norbornenes other than dicyclopentadiene, and linear or cyclic olefins or dienes. However, the content of the compound other than dicyclopentadiene in the monomer is preferably 2% by weight or less, and more preferably 1% by weight or less.

  The ring-opening polymerization catalyst is not particularly limited as long as it is capable of ring-opening polymerization of dicyclopentadiene and can impart crystallinity to the target dicyclopentadiene ring-opening polymer hydride. Specific examples of the ring-opening polymerization catalyst that can be used include, for example, Polymer Science Society Proceedings, 2002, Vol. 8, p. No. 1629-1630, an isotactic dicyclopentadiene ring-opened polymer, a complex of tungsten or molybdenum with two biphenoxy groups coordinated; A group 6 transition metal compound of the periodic table to which an aryloxy group having a hydroxyl group or an alkoxyl group having a hydroxyl group is bonded, which can obtain a syndiotactic dicyclopentadiene ring-opening polymer as described; A periodic table having an imide group having a hydrocarbon group with a specific structure as a substituent on nitrogen, which can obtain a syndiotactic dicyclopentadiene ring-opened polymer as described in Kaikai 2006-52333 A Group 6 transition metal compound; However, from the viewpoint of particularly improving the heat resistance of the target dicyclopentadiene ring-opening polymer hydride, ring-opening polymerization that can give syndiotactic stereoregularity to the dicyclopentadiene ring-opening polymer A catalyst is preferably used, and among them, a ring-opening polymerization catalyst comprising a metal compound represented by the following formula (1) is suitable.

M (NR ¹ ) X _4-a (OR ² ) _a · L _b (1)

(In the formula (1), M is a metal atom selected from Group 6 transition metal atoms in the periodic table, and R ¹ has a substituent at at least one of the 3, 4, and 5 positions. Or a group represented by —CH ₂ R ³ , wherein R ² is a group selected from an optionally substituted alkyl group and an optionally substituted aryl group X is a group selected from a halogen atom, an alkyl group, an aryl group and an alkylsilyl group, L is an electron-donating neutral ligand, a is 0 or 1, and b is 0 And R ³ is a group selected from a hydrogen atom, an alkyl group which may have a substituent, and an aryl group which may have a substituent.

  The metal atom (M in formula (1)) constituting the metal compound represented by formula (1) is selected from group 6 transition metal atoms (chromium, molybdenum, tungsten) in the periodic table. Among these, molybdenum or tungsten is preferably used, and tungsten is particularly preferably used.

The metal compound represented by Formula (1) comprises a metal imide bond. The substituent on the nitrogen atom constituting the metal imide bond (R ¹ in the formula (1)) is a phenyl group which may have a substituent at at least one of the 3, 4, and 5 positions, or- A group represented by CH ₂ R ³ (wherein R ³ is a group selected from a hydrogen atom, an alkyl group which may have a substituent and an aryl group which may have a substituent); It is. Examples of the substituent that the phenyl group which may have a substituent at at least one of the 3, 4, and 5 positions include an alkyl group such as a methyl group and an ethyl group; a fluorine atom, a chlorine atom, and a bromine atom A halogen atom such as; an alkoxy group such as a methoxy group, an ethoxy group, and an isopropoxy group; and the like, and further, substituents present in at least two positions of the 3, 4, and 5 positions are bonded to each other. Also good. Specific examples of the phenyl group which may have a substituent at at least one of the 3, 4, and 5 positions include an unsubstituted phenyl group, a 4-methylphenyl group, a 4-chlorophenyl group, and 3-methoxyphenyl. Groups, monosubstituted phenyl groups such as 4-cyclohexylphenyl group, 4-methoxyphenyl group; 3,5-dimethylphenyl group, 3,5-dichlorophenyl group, 3,4-dimethylphenyl group, 3,5-dimethoxyphenyl group Disubstituted phenyl groups such as 3,4,5-trimethylphenyl groups, 3,4,5-trichlorophenyl groups and the like; 2-naphthyl groups, 3-methyl-2-naphthyl groups, 4-methyl 2-naphthyl group which may have a substituent such as a 2-naphthyl group;

In the metal compound represented by the formula (1), in the group represented by —CH ₂ R ³ that can be used as a substituent on the nitrogen atom (R ¹ in the formula (1)), R ³ is a hydrogen atom. Represents a group selected from an alkyl group which may have a substituent and an aryl group which may have a substituent. The number of carbon atoms of the alkyl group which may be a substituent and can be a group represented by R ³ is not particularly limited, but is usually 1 to 20, preferably 1 to 10. The alkyl group may be linear or branched. Although the substituent which this alkyl group may have is not specifically limited, For example, the phenyl group which may have substituents, such as a phenyl group and 4-methylphenyl group; Alkoxyl groups, such as a methoxy group and an ethoxy group; Can be mentioned.

In the metal compound represented by the formula (1), an aryl group which may be used as a substituent on the nitrogen atom (R ¹ in the formula (1)) and may have a substituent includes a phenyl group, Examples include 1-naphthyl group, 2-naphthyl group, and aryl groups in which hydrogen atoms of these groups are replaced with other substituents. Further, the substituent of this aryl group is not particularly limited, but for example, a phenyl group which may have a substituent such as a phenyl group or a 4-methylphenyl group; an alkoxyl group such as a methoxy group or an ethoxy group; Can be mentioned.

The group represented by R ³ has 1 carbon number such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, octyl group and decyl group. ˜20 alkyl groups are particularly preferably used.

  The metal compound represented by the formula (1) has 3 or 4 groups selected from a halogen atom, an alkyl group, an aryl group, and an alkylsilyl group. That is, in the formula (1), X represents a group selected from a halogen atom, an alkyl group, an aryl group, and an alkylsilyl group. In addition, when there are two or more groups represented by X in the metal compound represented by the formula (1), these groups may be bonded to each other.

  Examples of the halogen atom that can be a group represented by X include a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a pentyl group, a neopentyl group, a benzyl group, and a neophyll group. Examples of the aryl group include a phenyl group, a 4-methylphenyl group, a 2,6-dimethylphenyl group, a 1-naphthyl group, and a 2-naphthyl group. Examples of the alkylsilyl group include a trimethylsilyl group, a triethylsilyl group, and a t-butyldimethylsilyl group.

The metal compound represented by the formula (1) may have one metal alkoxide bond or one metal aryloxide bond. The substituent on the oxygen atom constituting this metal alkoxide bond or metal aryloxide bond (R ² in formula (1)) may have an alkyl group which may have a substituent and a substituent. It is a group selected from good aryl groups. The alkyl group which may have a substituent and the aryl group which may have a substituent which can be a group represented by R ² are the same as those in the group represented by R ³ described above. Can be used.

  The metal compound represented by the formula (1) may have one or two electron-donating neutral ligands. Examples of the electron-donating neutral ligand (L in the formula (1)) include electron-donating compounds containing atoms of Group 14 or Group 15 of the Periodic Table. Specific examples thereof include phosphines such as trimethylphosphine, triisopropylphosphine, tricyclohexylphosphine, and triphenylphosphine; ethers such as diethyl ether, dibutyl ether, 1,2-dimethoxyethane, and tetrahydrofuran; trimethylamine, triethylamine, pyridine, And amines such as lutidine; Among these, ethers are particularly preferably used.

As the metal compound represented by the formula (1) which is particularly preferably used as the ring-opening polymerization catalyst, a tungsten compound having a phenylimide group (M in the formula (1) is a tungsten atom and R ¹ is phenyl). A compound that is a group), among which a tetrachlorotungstenphenylimide (tetrahydrofuran) complex is particularly suitable.

  The metal compound represented by the formula (1) includes an oxyhalide of a Group 6 transition metal and phenyl isocyanates optionally having a substituent at at least one of the 3, 4, and 5 positions, or Mixing monosubstituted methyl isocyanates with an electron-donating neutral ligand (L) and, if necessary, alcohols, metal alkoxides, metal aryloxides (for example, JP-A-5-345817) Can be synthesized by the method described in 1). The synthesized metal compound represented by the formula (1) may be purified and isolated by crystallization or the like, or the catalyst synthesis solution may be used as it is as a ring-opening polymerization catalyst without purification. You can also.

  The amount of the metal compound represented by the formula (1) used as the ring-opening polymerization catalyst is such that the molar ratio of (metal compound: whole monomer used) is usually from 1: 100 to 1: 2,000,000, preferably Is used in an amount of 1: 500 to 1,000,000, more preferably 1: 1,000 to 1: 500,000. If the amount of catalyst is too large, it may be difficult to remove the catalyst. If the amount is too small, sufficient polymerization activity may not be obtained.

  In using the metal compound represented by the formula (1) as a ring-opening polymerization catalyst, the metal compound represented by the formula (1) can be used alone, but from the viewpoint of increasing the polymerization activity, the formula (1 It is preferable to use a metal compound represented by 1) and an organometallic reducing agent in combination. Examples of the organometallic reducing agent that can be used include organometallic compounds of Groups 1, 2, 12, 13, and 14 of the periodic table having a hydrocarbon group having 1 to 20 carbon atoms. Among these, organic lithium, organic magnesium, organic zinc, organic aluminum, or organic tin is preferably used, and organic aluminum or organic tin is particularly preferably used. Examples of the organic lithium include n-butyl lithium, methyl lithium, and phenyl lithium. Examples of the organic magnesium include butylethylmagnesium, butyloctylmagnesium, dihexylmagnesium, ethylmagnesium chloride, n-butylmagnesium chloride, and allylmagnesium bromide. Examples of the organic zinc include dimethyl zinc, diethyl zinc, and diphenyl zinc. Examples of organic aluminum include trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, diethylaluminum ethoxide, diisobutylaluminum isobutoxide, ethylaluminum diethoxide, isobutylaluminum diisobutoxide, etc. Can be mentioned. Examples of the organic tin include tetramethyltin, tetra (n-butyl) tin, and tetraphenyltin. The amount of the organometallic reducing agent used is preferably 0.1 to 100 moles, more preferably 0.2 to 50 moles, and 0.5 to 20 moles relative to the metal compound represented by the formula (1). Double is particularly preferred. If the amount used is too small, the polymerization activity may not be improved, and if it is too much, side reactions may easily occur.

  The polymerization reaction for obtaining the ring-opened polymer is usually carried out in an organic solvent. The organic solvent to be used is not particularly limited as long as the resulting ring-opening polymer or a hydrogenated product thereof can be dissolved or dispersed under predetermined conditions and does not inhibit the polymerization reaction or the hydrogenation reaction. Specific examples of the organic solvent include aliphatic hydrocarbons such as pentane, hexane, and heptane; cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decahydronaphthalene, bicycloheptane, and tricyclodecane. , Hexahydroindene, cyclooctane and other alicyclic hydrocarbons; benzene, toluene, xylene and other aromatic hydrocarbons; dichloromethane, chloroform, 1,2-dichloroethane and other halogenated aliphatic hydrocarbons; chlorobenzene, dichlorobenzene, etc. Halogen-containing aromatic hydrocarbons; nitrogen-containing hydrocarbon solvents such as nitromethane, nitrobenzene and acetonitrile; ethers such as diethyl ether and tetrahydrofuran; Others can be mixtures of these solvents. Among these solvents, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, and ethers are preferably used.

  The ring-opening polymerization reaction can be started by mixing the monomer, the metal compound represented by the formula (1), and, if necessary, an organometallic reducing agent. The order in which these components are added is not particularly limited. For example, a mixture of a metal compound represented by the formula (1) and the organometallic reducing agent may be added to the monomer and mixed, or the organometallic reducing agent may be represented by the monomer and the formula (1). A mixture with a metal compound to be added may be added and mixed, or a metal compound represented by formula (1) may be added to and mixed with a mixture of a monomer and an organometallic reducing agent. . Moreover, when mixing each component, the whole quantity of each component may be added at once, may be added in multiple times, and it is continuous over a comparatively long time (for example, 1 minute or more). It can also be added.

  The concentration of the monomer during the polymerization reaction in the organic solvent is not particularly limited, but is preferably 1 to 50% by weight, more preferably 2 to 45% by weight, and particularly 3 to 40% by weight. preferable. If the monomer concentration is too low, the productivity of the polymer may be deteriorated. If it is too high, the solution viscosity after polymerization is too high, and the subsequent hydrogenation reaction may be difficult.

  An activity regulator may be added to the polymerization reaction system. The activity adjusting agent can be used for the purpose of stabilizing the ring-opening polymerization catalyst, adjusting the polymerization reaction rate and the molecular weight distribution of the polymer. The activity regulator is not particularly limited as long as it is an organic compound having a functional group, but is preferably an oxygen-containing, nitrogen-containing, or phosphorus-containing organic compound. Specifically, ethers such as diethyl ether, diisopropyl ether, dibutyl ether, anisole, furan and tetrahydrofuran; ketones such as acetone, benzophenone and cyclohexanone; esters such as ethyl acetate; nitriles such as acetonitrile benzonitrile; triethylamine , Triisopropylamine, quinuclidine, amines such as N, N-diethylaniline; pyridines such as pyridine, 2,4-lutidine, 2,6-lutidine, 2-t-butylpyridine; triphenylphosphine, tricyclohexylphosphine Phosphines such as triphenyl phosphate and trimethyl phosphate; triphenyl phosphine, tricyclohexyl phosphine, triphenyl phosphate, trimethyl phosphate - phosphines such as preparative; phosphine oxides such as triphenylphosphine oxide; but like, but not limited to. These activity regulators can be used singly or in combination of two or more. The amount of the activity regulator to be added is not particularly limited, but it may be usually selected between 0.01 and 100 mol% with respect to the metal compound used as the ring-opening polymerization catalyst.

  Further, a molecular weight modifier may be added to the polymerization reaction system in order to adjust the molecular weight of the ring-opening polymer. Examples of molecular weight modifiers include α-olefins such as 1-butene, 1-pentene, 1-hexene and 1-octene; aromatic vinyl compounds such as styrene and vinyltoluene; ethyl vinyl ether, isobutyl vinyl ether, allyl glycidyl ether, acetic acid Oxygen-containing vinyl compounds such as allyl, allyl alcohol and glycidyl methacrylate; halogen-containing vinyl compounds such as allyl chloride; nitrogen-containing vinyl compounds such as acrylamide; 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1 , 6-heptadiene, 2-methyl-1,4-pentadiene, non-conjugated dienes such as 2,5-dimethyl-1,5-hexadiene; 1,3-butadiene, 2-methyl-1,3-butadiene, 2, 3-dimethyl-1,3-butadiene, 1 3-pentadiene, a conjugated diene such as 1,3-hexadiene; can be mentioned. The amount of the molecular weight modifier to be added may be determined according to the target molecular weight, but is usually selected in the range of 0.1 to 50 mol% with respect to the monomer used.

  Although there is no restriction | limiting in particular in superposition | polymerization temperature, Usually, it is the range of -78 degreeC-+200 degreeC, Preferably it is the range of -30 degreeC-+180 degreeC. The polymerization time is not particularly limited and depends on the reaction scale, but is usually in the range of 1 minute to 1000 hours.

  By using the ring-opening polymerization catalyst containing the metal compound represented by the formula (1) as described above, the ring-opening polymerization reaction of dicyclopentadiene is performed under the conditions as described above, thereby syndiotactic stereoregularity is achieved. A dicyclopentadiene ring-opening polymer can be obtained. If the conditions of the hydrogenation reaction are set appropriately, the tacticity of the ring-opening polymer will not change during the hydrogenation reaction, so this ring-opening polymer having syndiotactic stereoregularity should be used in the hydrogenation reaction. Thus, the target dicyclopentadiene ring-opening polymer hydride having crystallinity based on having syndiotactic stereoregularity can be obtained. The degree of syndiotactic stereoregularity of the ring-opening polymer can be adjusted by selecting the type of ring-opening polymerization catalyst.

  The weight average molecular weight (Mw) measured by gel permeation chromatography of the ring-opening polymer subjected to the hydrogenation reaction is not particularly limited, but is preferably 10,000 to 100,000 in terms of polystyrene. More preferably, it is 000-80,000. By subjecting the ring-opening polymer having such a weight average molecular weight to a hydrogenation reaction, it is possible to obtain a dicyclopentadiene ring-opening polymer hydride having an excellent balance between molding processability and heat resistance. The weight average molecular weight of the ring-opening polymer can be adjusted by adjusting the amount of the molecular weight modifier used during polymerization.

  The molecular weight distribution of the ring-opening polymer to be subjected to the hydrogenation reaction [ratio of polystyrene-equivalent number average molecular weight and weight average molecular weight (Mw / Mn) measured by gel permeation chromatography] is not particularly limited. It is 5-4.0, Preferably it is 1.6-3.5. By subjecting the ring-opening polymer having such a molecular weight distribution to a hydrogenation reaction, a dicyclopentadiene ring-opening polymer hydride having particularly excellent molding processability can be obtained. The molecular weight distribution of the ring-opening polymer can be adjusted by the monomer addition method and the monomer concentration during the polymerization reaction.

  The hydrogenation reaction of the ring-opening polymer can be performed by supplying hydrogen into the reaction system in the presence of a hydrogenation catalyst. Any hydrogenation catalyst can be used as long as it is generally used in the hydrogenation of olefin compounds, and is not particularly limited. Examples thereof include the following.

  As the homogeneous catalyst, a catalyst system comprising a combination of a transition metal compound and an alkali metal compound, such as cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, titanocene dichloride / n-butyllithium, zirconocene dichloride / sec- Examples include butyl lithium, tetrabutoxy titanate / dimethyl magnesium, and the like. Further, mention may be made of noble metal complex catalysts such as dichlorobis (triphenylphosphine) palladium, chlorohydridocarbonyltris (triphenylphosphine) ruthenium, bis (tricyclohexylphosphine) benzilidineruthenium (IV) dichloride, chlorotris (triphenylphosphine) rhodium. Can do.

  As the heterogeneous catalyst, nickel, palladium, platinum, rhodium, ruthenium, or a solid catalyst in which these metals are supported on a support such as carbon, silica, diatomaceous earth, alumina, titanium oxide, for example, nickel / silica, nickel / Examples of the catalyst system include diatomaceous earth, nickel / alumina, palladium / carbon, palladium / silica, palladium / diatomaceous earth, and palladium / alumina.

  The hydrogenation reaction is usually performed in an inert organic solvent. Examples of such inert organic solvents include aromatic hydrocarbons such as benzene and toluene; aliphatic hydrocarbons such as pentane and hexane; alicyclic hydrocarbons such as cyclohexane and decahydronaphthalene; tetrahydrofuran, ethylene glycol dimethyl ether, and the like. Ethers; and the like. The inert organic solvent is usually the same as the solvent used in the polymerization reaction, and the hydrogenation catalyst may be added to the polymerization reaction solution as it is and reacted.

  Although the suitable range of conditions varies depending on the hydrogenation catalyst system used, the reaction temperature is usually -20 ° C to + 250 ° C, preferably -10 ° C to + 220 ° C, more preferably 0 ° C to 200 ° C. . If the hydrogenation temperature is too low, the reaction rate may be too slow, and if it is too high, side reactions may occur. The hydrogen pressure is usually 0.01 to 20 MPa, preferably 0.05 to 15 MPa, and more preferably 0.1 to 10 MPa. If the hydrogen pressure is too low, the hydrogenation rate may be too slow, and if it is too high, there will be restrictions on the apparatus in that a high pressure reactor is required. Although reaction time will not be specifically limited if it can be set as the desired hydrogenation rate, Usually, it is 0.1 to 10 hours. After the hydrogenation reaction, the target dicyclopentadiene ring-opened polymer hydride may be recovered according to a conventional method, and the catalyst residue can be removed by a technique such as filtration.

  The hydrogenation rate (ratio of hydrogenated main chain double bonds) in the hydrogenation reaction of the ring-opening polymer is not particularly limited, but is preferably 98% or more, more preferably 99% or more, and particularly preferably 99.99. 5% or more. The higher the hydrogenation rate, the better the heat resistance of the finally obtained dicyclopentadiene ring-opening polymer hydride.

  In the film production method of the present invention, for example, a rectangular film is formed by a melt molding method using, as a raw material resin, a dicyclopentadiene ring-opened polymer hydride having crystallinity obtained as described above. In forming the dicyclopentadiene ring-opening polymer hydride into a film, a film can be obtained with good productivity by adopting a melt molding method. The dicyclopentadiene ring-opening polymer hydride can be used for melt molding alone, but if necessary, other components may be added to the melt molding without departing from the present invention. . Other components that can be added to the dicyclopentadiene ring-opening polymer hydride include antioxidants, nucleating agents, fillers, flame retardants, flame retardant aids, colorants, antistatic agents, plasticizers, UV absorbers , Polymeric materials other than light stabilizers, near-infrared absorbers, lubricants, and hydrogenated dicyclopentadiene ring-opening polymers having crystallinity. Among these, it is preferable to add an antioxidant from the viewpoint of making the obtained film difficult to be thermally deteriorated.

  The antioxidant is not particularly limited, and for example, a phenol-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant can be used. Among these, it is preferable to use a phenolic antioxidant.

  A conventionally well-known thing can be used as a phenolic antioxidant, for example, 2-t-butyl-6- (3-t-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2 , 4-di-t-amyl-6- (1- (3,5-di-t-amyl-2-hydroxyphenyl) ethyl) phenyl acrylate and the like, and JP-A Nos. 63-179953 and 1-168643. Acrylate compounds described in Japanese Patent Publication No. 1; octadecyl-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) ), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris (3,5 Di-t-butyl-4-hydroxybenzyl) benzene, tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane [ie, pentaerythrimethyl-tetrakis (3- (3,5-di-t-butyl-4-hydroxyphenylpropionate)], triethylene glycol bis (3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate) and the like Alkyl substituted phenol compounds; 6- (4-hydroxy-3,5-di-t-butylanilino) -2,4-bisoctylthio-1,3,5-triazine, 4-bisoctylthio-1,3 5-triazine, 2-octylthio-4,6-bis- (3,5-di-t-butyl-4-oxyanilino) -1,3,5-triazi Triazine group-containing phenol compounds, such as. The like Among these, alkyl-substituted phenolic antioxidants are particularly preferably used.

  Examples of phosphorus antioxidants include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, tris (nonylphenyl) phosphite, tris (dinonylphenyl) phosphite, tris (2,4-di-). -T-butylphenyl) phosphite, 10- (3,5-di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide Phosphite compounds; 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl phosphite), 4,4′isopropylidene-bis (phenyl-di-alkyl phosphite) Examples thereof include diphosphite compounds such as (the alkyl group having 12 to 15 carbon atoms).

  Examples of the sulfur-based antioxidant include dilauryl 3,3-thiodipropionate, dimyristyl 3,3′-thiodipropionate, distearyl 3,3-thiodipropionate, lauryl stearyl 3,3-thiodiprote. Pionate, pentaerythritol-tetrakis- (β-lauryl-thio-propionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5.5] undecane. It is done.

  Although the compounding quantity of antioxidant is not specifically limited, It is 0.001-5 weight part normally with respect to 100 weight part of dicyclopentadiene ring-opening polymer hydrides, Preferably it is the range of 0.1-3 weight part. Selected.

  In forming a dicyclopentadiene ring-opening polymer hydride having crystallinity into a rectangular film by a melt molding method, the melt molding method to be used is not particularly limited, and an extrusion molding method, a calendar molding method, a compression molding method, Inflation molding, injection molding, blow molding, and the like can be applied. Among these, it is preferable to apply an extrusion method that facilitates uniformizing the thickness of the film, and it is particularly preferable to apply an extrusion method using an extruder equipped with a T die. Note that “forming into a rectangular film” means that the film is formed into a shape capable of “holding four sides” in the step of crystallizing the film described below. It is not intended to be “shape”. In addition, it does not mean that a rectangular film is directly formed only by a melt molding method, but a non-rectangular film is formed by a melt molding method, and is then shaped into a rectangular shape by cutting off unnecessary portions. This also includes that.

  The molding temperature at the time of melt molding is not particularly limited, but it is usually higher than the melting point of the crystalline dicyclopentadiene ring-opening polymer hydride that is the raw material resin, and the dicyclopentadiene ring-opening polymer hydride is thermally decomposed. More specifically, it is preferably selected in the range of 270 to 400 ° C, more preferably in the range of 280 to 350 ° C.

  The rectangular film obtained by melt molding may be cooled to below the glass transition temperature of the raw material resin according to a conventional method and then subjected to the step of crystallizing the film described below, or the glass transition of the raw material resin. It can also be used for the process of crystallizing the film as it is without cooling to below the temperature.

  In the method for producing a film of the present invention, as a second step, the film is kept in tension by holding the four sides of the rectangular film obtained as described above, and this is used as a raw material resin for crystallinity. The film is crystallized by placing the dicyclopentadiene ring-opening polymer hydride having a temperature not lower than the glass transition temperature and not higher than the melting point. In this way, the film is kept in tension by holding the four sides of the rectangular film, and then placed under a temperature condition not lower than the glass transition temperature of the raw material resin of the film and not higher than the melting point (that is, annealed). Thus, the crystallization of the film can proceed without impairing the smoothness of the film obtained by the melt molding method. Note that “holding four sides” means holding each side of the four sides of the rectangular film by any holding means, but the total length of each side is not necessarily continuous. For example, it may be held intermittently by holding means arranged at a predetermined interval. In addition, “tensioned state” means a state where tension is applied, but when the film is substantially stretched (for example, when the stretching ratio in any direction is 1.1 times or more). Not included.

  The holding means for holding the four sides of the rectangular film is not particularly limited, but from the viewpoint of obtaining a film with more excellent smoothness, it is a holding means that does not come into contact with the film other than the sides of the film to be held. Further, from the viewpoint of keeping the film in a tensioned state without stretching, it is preferable that the holding means does not move relative to each other. As a specific example of such a holding means, as an example that can be applied to a relatively small rectangular film, there can be mentioned a rectangular form in which means capable of gripping a film such as a clip are attached at predetermined intervals. In the case of continuously annealing a long film, etc., it is preferable to hold two opposing sides with a tenter device when holding the four sides of the film. In the case where the two opposing sides are held by the tenter device, the means for holding the remaining two opposing sides is not particularly limited, but is preferably a holding means that can transfer the film while holding the film, Specific examples thereof include a combination of two rolls and a combination of an extruder and a take-up roll.

  In order to advance the crystallization of the film, the tensioned film needs to be placed under a temperature condition not lower than the melting point of the glass transition temperature of the dicyclopentadiene ring-opening polymer hydride having crystallinity as a raw material resin. The heating means for placing the film under such temperature conditions is not particularly limited, but a heating means for increasing the ambient temperature that does not require the heating means and the film to be in contact is preferably used. A heating furnace is preferred.

  The temperature at which the film is crystallized may be any temperature that is not lower than the glass transition temperature and not higher than the melting point of the crystallized dicyclopentadiene ring-opening polymer hydride that is the raw material resin. It is preferable to select, specifically, it is preferable to select in the range of 110 to 240 ° C, and more preferable to select in the range of 120 to 220 ° C. The time for placing the film under such temperature conditions is not particularly limited, but is usually 5 seconds or longer, preferably 10 seconds to 1 hour.

  The film after being subjected to the step of crystallizing the film as described above may be cooled to below the glass transition temperature in accordance with a conventional method such as cooling. The tension state of the film may be released after cooling for a predetermined time and before cooling or after cooling to less than the glass transition temperature, but from the viewpoint of facilitating the handling of the film, it is less than the glass transition temperature. It is preferable to unravel after cooling to about 1.

  By being subjected to the step of crystallizing the film as described above, the film obtained by the method for producing a film of the present invention can have a high crystallinity. The crystallinity of the obtained film may be appropriately selected according to the desired performance, but is preferably 10% or more, and preferably 15% or more from the viewpoint of imparting high heat resistance and chemical resistance to the film. It is preferable that The degree of crystallinity of the film can be easily adjusted by adjusting the time during which the film is placed at a temperature not lower than the glass transition temperature and not higher than the melting point of the raw material resin in the step of crystallizing the film.

  Moreover, since the size of a crystal can be made small in the film obtained by the method for producing a film of the present invention, high transparency can be imparted to the obtained film. Although the total light transmittance of the film obtained is not particularly limited, it is preferably 80% or more, and more preferably 85% or more in the case of a film having a thickness of 100 μm.

  The thickness of the film obtained by the film production method of the present invention may be appropriately set according to the intended use, and is not particularly limited, but is usually selected in the range of 10 to 250 μm, preferably 20 to 200 μm. Selected by range.

  As described above, according to the method for producing a film of the present invention, the crystallization of a film using a dicyclopentadiene ring-opened polymer hydride having crystallinity as a raw material resin is advanced without impairing the smoothness of the film. It becomes possible. Therefore, according to the method for producing a film of the present invention, a film particularly excellent in smoothness and heat resistance can be produced. The film obtained by the production method of the present invention takes advantage of the original characteristics of dicyclopentadiene ring-opening polymer hydride having these excellent properties and crystallinity, for example, in the food field, medical field, electronic / electric field, It can be suitably used for various applications such as the optical field, the consumer field, and the civil engineering field. Especially, it is suitable for uses in the food field, medical field, electronic / electric field, optical field and the like. In the food field, it can be used as wrap film, shrink film, food packaging bags for confectionery, pickles and the like. In the medical field, it can be used as an infusion bag, an infusion bag, a film for press-through packaging, a film for blister packaging, and the like. In the electronic / electric field, it can be used as a film for a flexible printed board, a film capacitor, a high-frequency circuit board film, an antenna board film, a battery separator film, a release film, and the like. In the optical field, it can be used as a retardation film, a polarizing film, a light diffusion sheet, a condensing sheet, an optical card, a touch panel substrate film, a flexible display substrate film, and the like.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, unless otherwise indicated, the part and% in each example are a basis of weight.

Moreover, the measurement and evaluation in each example were performed by the following methods.
(1) Molecular weight of polymer (weight average molecular weight and number average molecular weight)
Using a gel permeation chromatography (GPC) system HLC-8220 (manufactured by Tosoh Corporation), an H-type column (manufactured by Tosoh Corporation) was measured at 40 ° C. using tetrahydrofuran as a solvent, and was determined as a polystyrene equivalent value.
(2) Polymer hydrogenation rate
^It calculated | required based on < ¹ > H-NMR measurement.
(3) Glass transition temperature and melting point of dicyclopentadiene ring-opening polymer hydride A sample heated to 300 ° C. in a nitrogen atmosphere is rapidly cooled with liquid nitrogen, and 10 ° C./min using a differential operating calorimeter (DSC). The glass transition temperature and the melting point were determined respectively.
(4) Ratio of racemo dyad of dicyclopentadiene ring-opened polymer hydride Using ortho-dichlorobenzene-d4 as a solvent, an inverse-gated decoupling method is applied at 150 ° C. to perform ¹³ C-NMR measurement, and orthodichlorobenzene. -Based on the intensity ratio of the 43.35 ppm signal derived from meso dyad and the 43.43 ppm signal derived from racemo dyad, using the 127.5 ppm peak of -d4 as a reference shift, the ratio of racemo dyad was determined. .
(5) Crystallinity degree of film It calculated from the diffraction peak area using the wide-angle X-ray-diffraction apparatus (Rigaku company make, brand name "RINT2500").
(6) Total light transmittance of film The total light transmittance was measured in the wavelength range of 400 to 700 nm using an ultraviolet / visible spectrometer (manufactured by JASCO, trade name “V-550”).
(7) Dimensional change rate after heating of film An A4 size film (210 mm × 297 mm) was cut into a size of 100 mm × 10 mm to prepare a sample. At this time, a sample having a long side in the extrusion direction (MD) during extrusion molding of the film and a sample having a long side in the direction (TD) perpendicular to the extrusion direction were prepared. About these samples, the length (Y1) of the long side of a sample was measured at 23 degreeC using the precision dimension measuring apparatus (The Nikon Instec company make, brand name "NEXIV VME-1515"). Next, this sample was heated in air at 150 ° C. for 1 hour. The sample after heating was observed, and the length (Y2) of the long side of the sample was measured at 23 ° C. in the same manner as before heating. Based on these measurement results, the dimensional change rate after heating the film was determined by the following equation.
Dimensional change rate (%) = {(Y1-Y2) / Y1} × 100
In addition, 10 samples were prepared for each, and the dimensional change rate was determined as an average value. The smaller the dimensional change rate, the better the heat resistance.

[Synthesis Example] (Synthesis of dicyclopentadiene ring-opening polymer hydride having crystallinity)
After fully drying, a pressure-resistant reaction vessel made of nitrogen-substituted glass was charged with 40 parts of a 75% cyclohexane solution of dicyclopentadiene (endo content 99% or more) (30 parts as the amount of dicyclopentadiene). 738 parts of cyclohexane and 1.9 parts of 1-hexene were added and heated to 50 ° C. Meanwhile, to a solution of 1.1 parts of tetrachlorotungstenphenylimide (tetrahydrofuran) complex in 56 parts of toluene, 4.6 parts of 19% diethylaluminum ethoxide / n-hexane solution was added and stirred for 10 minutes, A catalyst solution was prepared. This catalyst solution was added to the reactor to initiate a ring-opening polymerization reaction. Then, while maintaining 50 ° C., 40 parts of a 75% dicyclopentadiene / cyclohexane solution was added 9 times every 5 minutes (a total of 360 parts was added), and then the reaction was continued for 2 hours. Thereafter, a small amount of isopropanol was added to stop the polymerization reaction, and then the polymerization reaction solution was poured into a large amount of isopropanol to solidify the polymer. After the solidified polymer was separated from the solution by filtration and the polymer was recovered, the obtained polymer was dried at 40 ° C. under reduced pressure for 20 hours. The yield of the polymer (dicyclopentadiene ring-opening polymer) was 296 parts (yield: 99%). Further, the number average molecular weight (Mn) and the weight average molecular weight (Mw) of this polymer were 15,600 and 30,000, respectively, and the molecular weight distribution (Mw / Mn) determined therefrom was 1.92. It was. Subsequently, 60 parts of the obtained polymer and 261 parts of cyclohexane were added to a pressure-resistant reaction vessel and stirred. After the polymer was dissolved in cyclohexane, 0.039 part of chlorohydridocarbonyltris (triphenylphosphine) ruthenium was added to 40 parts of toluene. The hydrogenation catalyst solution dispersed in was added, and a hydrogenation reaction was carried out at a hydrogen pressure of 4 MPa and 160 ° C. for 5 hours. The obtained hydrogenation reaction solution is poured into a large amount of isopropyl alcohol to completely precipitate the polymer, washed by filtration, dried under reduced pressure at 60 ° C. for 24 hours, and crystallized dicyclopentadiene ring-opened polymer hydrogen The compound was obtained. The hydrogenation rate of the dicyclopentadiene ring-opening polymer hydride was 99% or more, the glass transition temperature was 96 ° C., the melting point was 265 ° C., and the ratio of racemo dyad was 68%.

[Example 1]
Antioxidant (tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4′-hydroxyphenyl) propionate] methane was added to 100 parts of the dicyclopentadiene ring-opened polymer hydride obtained in the synthesis example. , Trade name "Irganox 1010" (manufactured by BASF Japan Ltd.) 0.8 parts, melt-kneaded at a resin temperature average of 280 ° C by a twin screw extruder, and pelletized by a pelletizer to obtain raw resin pellets . This pellet was melt extruded at a speed of 1.5 m / min using an extruder (barrel temperature: 280 ° C., T die temperature: 290 ° C., cooling roll temperature: 90 ° C.) equipped with a T die having a width of 300 mm, By cooling to room temperature after extrusion, a film having a thickness of 100 μm was formed, and this was wound up by a take-up roll having the same speed as the melt extrusion speed. When a part of the obtained film was cut out and the crystallinity was measured, the crystallinity was 4%. Next, a 300 mm × 500 mm film was cut out from the film wound up on a roll. Along with the four sides of the cut out film, a polyimide tape having a width of 10 mm is applied to both the front and back surfaces, and a 25 mm wide clip is formed on the four sides of an aluminum frame having the same size as the cut out film without any gaps. It attached so that the part which affixed the polyimide tape might be hold | gripped on the formwork attached side by side by all the clips, and the film was made into the tension state. And the formwork with which the film was attached was left still for 30 minutes in the oven heated at 150 degreeC. After leaving still for 30 minutes, it cooled to room temperature, took out the film from the mold, and cut off the side part of the film, and produced A4 size (210 mm x 297 mm) film. About the obtained film, after observing the surface, the crystallinity, the total light transmittance, and the dimensional change rate after heating were measured. These results are summarized in Table 1.

[Example 2]
A film was produced in the same manner as in Example 1 except that the heating temperature of the oven in which the mold was placed was changed from 150 ° C to 120 ° C. About the obtained film, after observing the surface, the crystallinity, the total light transmittance, and the dimensional change rate after heating were measured. These results are summarized in Table 1.

Example 3
A film was produced in the same manner as in Example 1 except that the heating temperature of the oven in which the mold was placed was changed from 150 ° C. to 200 ° C. About the obtained film, after observing the surface, the crystallinity, the total light transmittance, and the dimensional change rate after heating were measured. These results are summarized in Table 1.

[Comparative Example 1]
The film wound on the take-up roll obtained in Example 1 was cut into A4 size (210 mm × 297 mm), and the film surface was observed, and the degree of crystallinity, total light transmittance, and dimensional change after heating were measured. Was measured. These results are summarized in Table 1.

[Comparative Example 2]
The film wound on the take-up roll obtained in Example 1 was cut into A4 size (210 mm × 297 mm), placed on the plate of this film, and for the purpose of preventing the film from moving due to the wind pressure in the oven. The four corners were fixed to the plate with polyimide tape. However, this fixation was performed with a slack so that the film would not become tensioned. Next, the film fixed to the plate was heated in an oven heated to 150 ° C. for 30 minutes. After cooling, the film was removed from the plate, and the film surface was observed, and the crystallinity, total light transmittance, and dimensional change after heating were measured. These results are summarized in Table 1.

[Comparative Example 3]
In attaching the film to the mold, a film was produced in the same manner as in Example 1 except that only the short side portion of the film was held by the clip over the entire length, and the long side was not held by the clip. About the obtained film, after observing the surface, the crystallinity, the total light transmittance, and the dimensional change rate after heating were measured. These results are summarized in Table 1.

[Comparative Example 4]
In the same manner as in Example 1, a film was formed by melt extrusion molding. However, when winding the film on the take-up roll, the film was taken up on the take-up roll while the film was stretched along the take-up direction by setting the take-up speed to twice the extrusion speed. The film wound around the take-up roll was cut into A4 size (210 mm × 297 mm), and the film surface was observed, and crystallinity, total light transmittance, and dimensional change after heating were measured. These results are summarized in Table 1.

Example 4
The film wound on the take-up roll obtained in Example 1 was heat-treated in a heating furnace equipped with a tenter device. Specifically, a heating furnace equipped with a tenter device is installed between two rolls, and while maintaining the tension of the film between the rolls, the tenter device holds the side of the film and the tension perpendicular to the take-off direction is maintained. While being applied (however, the film was not substantially stretched), the film in this state was passed through a heating furnace at 150 ° C. over 1 minute, and the film was wound on a take-up roll. The film wound around the take-up roll was cut into A4 size (210 mm × 297 mm), and the film surface was observed, and crystallinity, total light transmittance, and dimensional change after heating were measured. These results are summarized in Table 2.

[Comparative Example 5]
A heat treatment was performed in the same manner as in Example 2 except that the tenter apparatus was not used (that is, the tension perpendicular to the take-up direction was not applied to the film), and the film was wound on a take-up roll. The film wound around the take-up roll was cut into A4 size (210 mm × 297 mm), and the film surface was observed, and crystallinity, total light transmittance, and dimensional change after heating were measured. These results are summarized in Table 2.

  As can be seen from the results shown in Tables 1 and 2, the film is held in tension by holding the four sides of the film, and this is placed under a temperature condition not lower than the glass transition temperature of the raw material resin and not higher than the melting point (annealing treatment). Therefore, the film is smooth with no unevenness and streaks on the surface, excellent in transparency, and maintains a smooth state with almost no deformation even when heated at 150 ° C. for 1 hour. (Examples 1 to 5). On the other hand, when the film is not crystallized, the degree of crystallinity of the resulting film is low and the heat resistance is poor (Comparative Example 1). Moreover, when the crystallization of the film is performed by stretching, streaks are generated on the surface of the obtained film, and the heat resistance of the film is inferior (Comparative Example 4). In addition, even when the film is crystallized by annealing treatment, when the film is not held or when only two sides are held, unevenness and streaks occur on the surface of the obtained film, The heat resistance of the film is also inferior (Comparative Examples 2, 3, and 5). From the above, it can be said that according to the method for producing a film of the present invention, a film particularly excellent in smoothness and heat resistance can be obtained.

Claims (2)

A step of molding a raw material resin, which is a hydrogenated dicyclopentadiene ring-opening polymer, having a racemo dyad ratio of 55% or more into a rectangular film by a melt molding method, and four sides of the obtained film Holding the film as a tensioned state without stretching the film , placing the film under a temperature condition not lower than the glass transition temperature of the raw material resin and not higher than the melting point, thereby crystallizing the film, .   The method for producing a film according to claim 1, wherein, in the step of crystallizing the film, when the four sides of the film are held, two sides facing each other are held by a tenter device.