JP5159215B2 - Capacitor film raw sheet made of polypropylene resin, capacitor film, and production method thereof - Google Patents

Description

  The present invention relates to an original sheet for capacitor film and a capacitor film made of polypropylene resin. Specifically, the present invention relates to a raw film sheet for a capacitor film made of a specific polypropylene resin having a wide molecular weight distribution and containing a large amount of a polymer, and a film suitable as a capacitor film obtained by stretching the sheet.

  Polypropylene resins are used for food packaging or industrial sheets or films because they have high mechanical strength, high electrical insulation, and excellent food hygiene and transparency.

  Polypropylene resins usually have crystal forms such as α crystals and β crystals, and various physical properties can be imparted using the crystal forms. The β crystal is characterized by a lower density and a lower melting point than the α crystal. Although it is known that a small amount of β crystal is generated when the molten polypropylene resin is slowly cooled, it is difficult to obtain a polypropylene resin having a high β crystal fraction. In order to obtain a polypropylene resin with a high β crystal fraction, a β crystal nucleating agent is added, but such a β crystal nucleating agent is required to have electrical insulation like a capacitor film for a capacitor. It was unsuitable for use.

  Polypropylene resin films usually contain a small amount of slip agent and anti-blocking agent in order to improve slipping. However, the electrical properties are required for applications that require electrical greenness, such as capacitor films for capacitors. The composition of slipping agents and anti-blocking agents that are damaged is limited.

  When producing a capacitor film for a capacitor, it is desirable to stretch a polypropylene resin sheet having a high β crystal fraction, cause a transition from β crystal to α crystal, and form irregularities on the film surface to provide anti-blocking properties. However, because of the above-mentioned limitations, for example, blending fine particles of a resin having no polar group such as polyethylene resin or slowly cooling a melted polypropylene resin to form a β crystal and stretching it Things are done.

  In recent years, the production of polypropylene resins often uses magnesium-supported titanium catalyst components, but sufficient β-crystals can be obtained with polypropylene resins having a narrow molecular weight distribution typified by polypropylene resins obtained using magnesium-supported titanium-based catalysts. It has been desired to develop and improve a polypropylene resin that is difficult to produce and capable of generating a large amount of β crystals.

As a method for obtaining a highly stereoregular polypropylene with high activity in order to improve the mechanical strength represented by rigidity and the like using the magnesium-supported titanium-based catalyst, for example, JP-A-2-229805 (Patent Document) 1), Japanese Patent Laid-Open No. 7-25946 (Patent Document 2), and the like. However, when olefin polymerization is performed using such a highly stereoregular catalyst, the resulting polyolefin has a narrow molecular weight distribution and crystallinity. As a result, even if it is heated and melted and extruded from a T-die, it is β crystal. In general, hardly formed.

The applicant of the present application is able to produce a sheet having a broad molecular weight distribution and a high β crystal fraction, which is suitable for the production of a capacitor film, because the polypropylene resin obtained by multistage polymerization using a supported titanium-based catalyst. Have already been proposed (Japanese Patent Application Laid-Open No. 2004-2655).
No. (Patent Literature 3) and JP-A No. 2004-175932 (Patent Literature 4)). However, these techniques have a problem that the process is complicated because it is necessary to produce a polypropylene resin as a raw material by multistage polymerization.

For this reason, a polypropylene resin sheet having a high β crystal fraction and a capacitor film obtained by stretching the polypropylene resin sheet can be prepared by a simpler method and produced from a polypropylene resin having a broad molecular weight distribution without using a nucleating agent. As a result, the appearance of a suitable film has been demanded.
JP-A-2-229805 Japanese Patent Laid-Open No. 7-25946 JP 2004-2655 A JP 2004-175932 A

  The present invention relates to a polypropylene resin sheet having a high β crystal fraction produced from a polypropylene resin having a wide molecular weight distribution prepared by a simple method without using a nucleating agent, and a capacitor film obtained by stretching the same. It is an object to provide a suitable film.

The raw sheet for capacitor film of the present invention is ASTM D-1238 (230 ° C., 2
. The melt flow rate (MFR) measured at 16 kg load) is 0.5 to 10 g / 10 min, the Mw / Mn value obtained from the measured value by gel permeation chromatography (GPC) is 6 to 30, and Mz It is characterized by being obtained by extruding a polypropylene resin having a / Mw value of 4-15.

  Such an original sheet for capacitor film of the present invention is preferably obtained by heating and melting the polypropylene resin, extruding it from a T die, and slowly cooling it with a cooling roll maintained at a temperature of 60 ° C. or higher.

In the raw sheet for capacitor film of the present invention, the polypropylene resin is preferably a resin obtained by one-step polymerization.
In the original sheet for capacitor film of the present invention, the polypropylene resin is
A solid titanium catalyst component (I) containing titanium, magnesium, halogen and a cyclic ester compound (a) specified by the following formula (1);
An organometallic compound catalyst component (II);
A polymer obtained by polymerization in the presence of an olefin polymerization catalyst containing an electron donor (III) as required is preferred.

[In Formula (1), n is an integer of 5-10.
R ² and R ³ are each independently COOR ¹ or R, and at least one of R ² and R ³ is COOR ¹ .

A single bond in the cyclic skeleton (excluding ^a C ^a -C ^a bond and a C ^a -C ^b bond when R ³ is R) may be replaced with a double bond.
A plurality of R ¹ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms.

  A plurality of Rs are each independently an atom or group selected from a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a nitrogen-containing group, an oxygen-containing group, a phosphorus-containing group, a halogen-containing group and a silicon-containing group. And may be bonded to each other to form a ring.

The ring skeleton formed by bonding R to each other may contain a double bond. When the ring skeleton contains two or more C ^a to which COOR ¹ is bonded, The number of carbon atoms constituting the skeleton is 5-10. ]
The raw sheet for capacitor film of the present invention preferably has a β crystal fraction of 0.20 or more.
The film of the present invention is characterized in that it is obtained by stretching the original sheet for capacitor film of the present invention.

The film of the present invention is preferably a capacitor film.
The manufacturing method of the original film for capacitor films of this invention is ASTM D-1238 (2
The melt flow rate (MFR) measured at 30 ° C. and a load of 2.16 kg is 0.5 to 10 g / 10 min, and the Mw / Mn value obtained from the measured value by gel permeation chromatography (GPC) is 6 to 6 A polypropylene resin having a Mz / Mw value of 4 to 15 is 30, extruded from a T die, and gradually cooled with a cooling roll maintained at a temperature of 60 ° C. or higher.

The film production method of the present invention has a melt flow rate (MFR) measured by ASTM D-1238 (230 ° C., 2.16 kg load) of 0.5 to 10 g / 10 min, and gel permeation chromatography (GPC). The polypropylene resin having an Mw / Mn value of 6 to 30 and an Mz / Mw value of 4 to 15 obtained from the measured value obtained by the above method was heated and melted and extruded from a T die, and kept at a temperature of 60 ° C. or higher. A step of slowly cooling with a cooling roll to form a sheet,
It has the extending process.

  According to the present invention, by using a specific polypropylene resin having a wide molecular weight distribution and containing a large amount of a high molecular weight component, a β crystal fraction is high without using a β crystal nucleating agent and the like, and is suitable for use in manufacturing a capacitor film. The raw film sheet | seat for capacitor films used for this, the film suitable for the capacitor film use obtained by extending | stretching this sheet | seat, and its manufacturing method can be provided.

  According to the present invention, a raw sheet for capacitor film having a high β crystal fraction can be easily produced without blending a β crystal nucleating agent. The raw sheet for capacitor film of the present invention has a high β crystal fraction, and the film of the present invention obtained by stretching this has a fine and uniform surface irregularity, excellent anti-blocking properties, and electrical insulation. Is also excellent as a capacitor film.

Hereinafter, the present invention will be specifically described.
Polypropylene resin The raw sheet or film for a capacitor film of the present invention is obtained using a specific polypropylene.

  The polypropylene resin according to the present invention is a crystalline polypropylene resin, and is a propylene homopolymer or a copolymer of propylene and ethylene or an α-olefin having 4 to 20 carbon atoms. Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like can be mentioned. Among these, ethylene or an α-olefin having 4 to 10 carbon atoms is preferable. These α-olefins may form a random copolymer with propylene, or may form a block copolymer. The content of the structural unit derived from these α-olefins is 5 mol% or less, preferably 2 mol% or less in the polypropylene resin.

Polypropylene resin according to the present invention is ASTM D-1238 (230 ° C., 2.16 k).
The melt flow rate (MFR) measured by (g load) is in the range of 0.5 to 10 g / 10 minutes, preferably 1 to 8 g / 10 minutes, more preferably 1.5 to 5 g / 10 minutes. When the MFR is in this range, the formability and appearance of the sheet or film are excellent.

  The polypropylene resin according to the present invention desirably has an Mw / Mn value of 6 to 30, preferably 7 to 20, more preferably 8 to 18, as determined from a measurement value by gel permeation chromatography (GPC). The Mz / Mw value obtained from the measured value by gel permeation chromatography (GPC) is 4 to 15, preferably 4.5 to 15, and more preferably 5 to 10. Further, the Mz / Mn value of the olefin polymer used in the present invention is preferably 25 or more, more preferably 30 or more, and particularly preferably 40 or more. The upper limit of the Mz / Mn value is preferably 300, more preferably 250, and particularly preferably 200.

Such a polypropylene resin according to the present invention can be produced by multi-stage polymerization or mixing of a plurality of types of polypropylene, but is preferably a resin obtained by one-stage polymerization. When the polypropylene resin according to the present invention is a resin obtained by one-step polymerization, the polymer production apparatus can be made simpler and economical, and the high molecular weight component in the polypropylene resin can be reduced. This is preferable because it is in a more finely dispersed state.

  Since the polypropylene resin of the present invention has a large Mw / Mn value and contains a large amount of a high molecular weight component, the high molecular weight component in the polypropylene resin acts as a nucleating agent during molding, such as filler powder and resin powder. A molded body having a high degree of crystallinity can be obtained without adding a nucleating agent. In particular, when a sheet is formed by extrusion, a sheet having a high β crystal fraction is easily obtained. Furthermore, if the polypropylene resin is obtained by one-step polymerization, the high molecular weight component is considered to be more finely dispersed, so that the produced β crystals are small and the dispersion is good. This is preferable because the number of irregularities formed by conversion is large, and a uniformly dispersed sheet can be expected.

Such a polypropylene resin according to the present invention is preferably produced using the following olefin polymerization catalyst.
Olefin Polymerization Catalyst The polypropylene resin according to the present invention is an olefin polymerization catalyst comprising a solid titanium catalyst component (I), an organometallic compound catalyst component (II), and, if necessary, an electron donor (III). It is preferably obtained by polymerization in the presence.

・ Solid titanium catalyst component (I)
The solid titanium catalyst component (I) according to the present invention contains titanium, magnesium, halogen and a cyclic ester compound (a) represented by the following formula (1).

<Cyclic ester compound (a)>
The cyclic ester compound (a) constituting the solid titanium catalyst component (I) according to the present invention is a compound represented by the following formula (1).

In the formula (1), n is an integer of 5 to 10, preferably an integer of 5 to 7, particularly preferably 6. C ^a and C ^b represent carbon atoms.
R ² and R ³ are each independently COOR ¹ or R, and at least one of R ² and R ³ is COOR ¹ , preferably R ² is COOR ¹ .

The carbon-carbon bonds in the cyclic skeleton are preferably all single bonds, but any of the cyclic skeleton other than the C ^a -C ^a bond and the C ^a -C ^b bond when R ³ is R are used. These single bonds are
It may be replaced with a double bond.

A plurality of R ^{1 s} are each independently a monovalent carbon atom having 1 to 20, preferably 1 to 10, more preferably 2 to 8, more preferably 4 to 8, particularly preferably 4 to 6 carbon atoms. It is a hydrogen group. As this hydrocarbon group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, hexyl group, heptyl group, octyl group, 2-ethylhexyl group, decyl group, dodecyl group, tetradecyl group, A hexadecyl group, an octadecyl group, an eicosyl group, and the like can be mentioned. Among them, an n-butyl group, an isobutyl group, a hexyl group, and an octyl group are preferable, and an n-butyl group and an isobutyl group are more preferable.

  A plurality of R's are each independently an atom selected from a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a nitrogen-containing group, an oxygen-containing group, a phosphorus-containing group, a halogen-containing group and a silicon-containing group. Or a group. Of the above R, at least one is preferably not a hydrogen atom.

  Among these, R other than a hydrogen atom is preferably a hydrocarbon group having 1 to 20 carbon atoms. Examples of the hydrocarbon group having 1 to 20 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an iso group. Aliphatic hydrocarbon groups such as -propyl group, n-butyl group, iso-butyl group, sec-butyl group, n-pentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, vinyl group, phenyl group, octyl group , An alicyclic hydrocarbon group, and an aromatic hydrocarbon group. Among them, an aliphatic hydrocarbon group is preferable, and specifically, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, and a sec-butyl group are preferable.

R may be bonded to each other to form a ring, and a ring skeleton formed by bonding of R to each other may contain a double bond, and in the ring skeleton, When two or more C ^a bonded with COOR ¹ are contained, the number of carbon atoms constituting the ring skeleton is 5 to 10.

Examples of such a ring skeleton include a norbornane skeleton and a tetracyclododecane skeleton.
R may be a carbonyl structure-containing group such as a carboxylate group, an alkoxy group, a siloxy group, an aldehyde group or an acetyl group, and these substituents contain one or more hydrocarbon groups. Is preferred.

As the cyclic ester compound (a) represented by the formula (1), any of compounds exemplified in International Publication Nos. WO2006 / 077945 and International Publication Nos. WO2006 / 077946 may be used. For example,
Cyclohexane-1,2-dicarboxylate,
Cyclohexane-1,2-dicarboxylate diisobutyl,
Dioctyl cyclohexane-1,2-dicarboxylate,
Cyclopentane-1,2-dicarboxylate diisobutyl,
Diisobutyl cycloheptane-1,2-dicarboxylate,
4-cyclohexene-1,2-dicarboxylate diethyl,
4-cyclohexene-1,2-dicarboxylate diisobutyl,
Dioctyl 4-cyclohexene-1,2-dicarboxylate,
3-methylcyclohexane-1,2-dicarboxylate diisobutyl,
Dioctyl 3-methylcyclohexane-1,2-dicarboxylate,
4-methylcyclohexane-1,2-dicarboxylate diethyl,
4-methylcyclohexane-1,2-dicarboxylate diisobutyl,
Diisobutyl 3,6-dimethylcyclohexane-1,2-dicarboxylate,
Dioctyl 3,6-dimethylcyclohexane-1,2-dicarboxylate,
3-methyl 6-n-propylcyclohexane-1,2-dicarboxylate diisobutyl,
Norbornane-1,2-dicarboxylate diisobutyl,
3-methyl 4-cyclohexene-1,2-dicarboxylate diisobutyl,
Dioctyl 3-methyl-4-cyclohexene-1,2-dicarboxylate,
4-methyl 4-cyclohexene-1,2-dicarboxylate,
4-methyl 4-cyclohexene-1,2-dicarboxylate diisobutyl,
Dioctyl 4-methyl 4-cyclohexene-1,2-dicarboxylate,
Examples include isobutyl 3,6-diphenyl-4cyclohexene-1,2-dicarboxylate.

Moreover, the dicarboxylic acid ester of the cyclic diol compound corresponding to these can also be mentioned as a suitable compound. As such compounds, in particular,
Cyclohexyl 1,2-diacetate,
Cyclohexyl 1,2-dibutanate,
Cyclohexyl 1,2-dibenzoate,
Cyclohexyl 1,2-ditoluate,
3,6-dimethylcyclohexyl 1,2-diacetate,
3,6-dimethylcyclohexyl 1,2-dibutanate,
3-methyl 6-propyl cyclohexyl 1,2-diol acetate,
3-methyl 6-propyl cyclohexyl 1,2-dibutanate,
3,6-dimethylcyclohexyl 1,2-dibenzoate,
3,6-dimethylcyclohexyl 1,2-ditoluate,
3-methyl 6-propyl cyclohexyl 1,2-dibenzoate,
3-methyl 6-propyl cyclohexyl 1,2-ditoluate,
Etc. can be mentioned as a preferable example.

  The cyclic ester compound (a) having a diester structure as described above has isomers such as cis and trans, and any structure has an effect meeting the object of the present invention. A higher content is preferred, and a higher trans isomer content tends to have not only the effect of broadening the molecular weight distribution but also the activity and the stereoregularity of the resulting polymer. The ratio of the trans form of the cis form and the trans form is preferably 51% or more. A more preferable lower limit value is 55%, further 60%, particularly 65%. On the other hand, the preferable upper limit is 100%, preferably 90%, more preferably 85%, and particularly 79%. When all of R in the formula (I) are hydrogen atoms, it may be particularly preferable from the viewpoint of molecular weight distribution that the ratio of the trans isomer is in the range of 51 to 79%. The reason for this is unknown, but it is presumed that the variation of the stereoisomer described later is in a region suitable for wide molecular weight distribution.

  A polypropylene resin produced by polymerization in the presence of an olefin polymerization catalyst containing the solid titanium catalyst component (I) containing the cyclic ester compound (a) as described above exhibits a wide molecular weight distribution and has a high molecular weight component. Therefore, it is extremely suitable as a polypropylene resin used in the present invention. Here, the reason why a polypropylene resin having a broad molecular weight distribution can be obtained is not clear, but it is thought to be due to the structure of the cyclic ester compound (a) as described below.

It is known that the cyclic hydrocarbon structure forms various three-dimensional structures such as a chair type and a boat type. In addition, when the cyclic structure has a substituent, the types of steric structures that can be taken are further increased. And that cyclic ester compound (a) can take various three-dimensional structures leads to formation of various active species on solid titanium catalyst component (I). In particular, of the carbon atoms forming the cyclic skeleton of the cyclic ester compound (a), if the bond between the carbon atom to which the ester group (COOR ¹ group) is bonded and the adjacent carbon atom is a single bond, it is removed. Wide variety of possible three-dimensional structures. As a result, when olefin polymerization is performed using the solid titanium catalyst component (I), olefin polymers having various molecular weights can be produced at one time, that is, an olefin polymer having a wide molecular weight distribution can be produced. it can.

These compounds may be used alone or in combination of two or more.
For the preparation of the solid titanium catalyst component (I) suitably used in the present invention, a magnesium compound and a titanium compound are used in addition to the cyclic ester compound (a).

<Magnesium compound>
Specifically, as the magnesium compound,
Magnesium halides such as magnesium chloride and magnesium bromide;
Alkoxy magnesium halides such as methoxy magnesium chloride, ethoxy magnesium chloride, phenoxy magnesium chloride;
Alkoxymagnesium such as ethoxymagnesium, isopropoxymagnesium, butoxymagnesium, 2-ethylhexoxymagnesium;
Aryloxymagnesium such as phenoxymagnesium;
Known magnesium compounds such as magnesium carboxylates such as magnesium stearate can be mentioned.

  These magnesium compounds may be used alone or in combination of two or more. These magnesium compounds may be complex compounds with other metals, double compounds, or mixtures with other metal compounds.

  Among these, a magnesium compound containing halogen is preferable, and magnesium halide, particularly magnesium chloride is more preferably used. In addition, alkoxymagnesium such as ethoxymagnesium is also preferably used. The magnesium compound may be derived from other substances, for example, obtained by contacting an organic magnesium compound such as a Grignard reagent with titanium halide, silicon halide, halogenated alcohol or the like. Good.

<Titanium compound>
Examples of titanium compounds include general formulas;
Ti (OR) _g X _4-g
(R is a hydrocarbon group, X is a halogen atom, and g is 0 ≦ g ≦ 4.)
The tetravalent titanium compound shown by these can be mentioned. More specifically,
Titanium tetrahalides such as TiCl ₄ and TiBr ₄ ;
Ti (OCH ₃ ) Cl ₃ , Ti (OC ₂ H ₅ ) Cl ₃ , Ti (O—n—C ₄ H ₉ ) Cl ₃ , Ti (OC ₂ H ₅ ) Br ₃ , Ti (O—isoC ₄ H ₉ ) Trihalogenated alkoxytitanium such as Br ₃ ;
Dihalogenated alkoxytitanium such as Ti (OCH ₃ ) ₂ Cl ₂ , Ti (OC ₂ H ₅ ) ₂ Cl ₂ ;
Monohalogenated alkoxytitanium such as Ti (OCH ₃ ) ₃ Cl, Ti (O—n—C ₄ H ₉ ) ₃ Cl, Ti (OC ₂ H ₅ ) ₃ Br;
Examples thereof include tetraalkoxytitanium such as Ti (OCH ₃ ) ₄ , Ti (OC ₂ H ₅ ) ₄ , Ti (OC ₄ H ₉ ) ₄ , and Ti (O-2-ethylhexyl) ₄ .

Among these, titanium tetrahalide is preferable, and titanium tetrachloride is particularly preferable. These titanium compounds may be used alone or in combination of two or more.
Examples of the magnesium compound and the titanium compound as described above may include compounds described in detail in JP-A-57-63310, JP-A-5-170843, and the like.

<Preparation of solid titanium catalyst component (I)>
For the preparation of the solid titanium catalyst component (I), a known method can be used without limitation except that the cyclic ester compound (a) is used. Specific preferred methods include, for example, the following methods (P-1) to (P-4).

  (P-1) A solid adduct comprising a magnesium compound and a catalyst component (b), a cyclic ester compound (a) and a liquid titanium compound are contacted in a suspended state in the presence of an inert hydrocarbon solvent. How to make.

(P-2) A method in which a solid adduct comprising a magnesium compound and a catalyst component (b), a cyclic ester compound (a), and a titanium compound in a liquid state are contacted in a plurality of times.
(P-3) A solid adduct comprising a magnesium compound and a catalyst component (b), a cyclic ester compound (a), and a liquid titanium compound are contacted in a suspended state in the presence of an inert hydrocarbon solvent. And making it contact in multiple times.

(P-4) A method of contacting a magnesium compound in a liquid state comprising a magnesium compound and a catalyst component (b), a titanium compound in a liquid state, and the cyclic ester compound (a).
A preferable reaction temperature in the preparation of the solid titanium catalyst component (I) is -30 ° C to 150 ° C, more preferably -25 ° C to 130 ° C, and further preferably -25 ° C to 120 ° C.

  The production of the solid titanium catalyst component can also be carried out in the presence of a known medium, if necessary. Examples of the medium include aromatic hydrocarbons such as slightly polar toluene and known aliphatic hydrocarbons such as heptane, octane, decane, and cyclohexane, and alicyclic hydrocarbon compounds. Hydrocarbon is a preferred example.

  When the polymerization reaction is carried out using the solid titanium catalyst component (I) produced within the above range, the effect of obtaining a polypropylene resin having a broad molecular weight distribution, the activity of the catalyst and the high stereoregularity of the obtained polypropylene resin Can be achieved at a higher level.

<Catalyst component (b)>
As the catalyst component (b) used for forming the solid adduct or the magnesium compound in a liquid state, a known compound that can solubilize the magnesium compound in a temperature range of about room temperature to about 300 ° C. is preferable. Aldehydes, amines, carboxylic acids and mixtures thereof are preferred. As these compounds, for example, JP-A-57-633.
Examples thereof include compounds described in detail in JP-A No. 10 and JP-A-5-170843.

More specifically, as an alcohol having the above-mentioned solubilizing ability of magnesium compound,
Aliphatic alcohols such as methanol, ethanol, propanol, butanol, isobutanol, ethylene glycol, 2-methylpentanol, 2-ethylbutanol, n-heptanol, n-octanol, 2-ethylhexanol, decanol, dodecanol;
Cycloaliphatic alcohols such as cyclohexanol and methylcyclohexanol;
Aromatic alcohols such as benzyl alcohol and methylbenzyl alcohol;
Examples thereof include aliphatic alcohols having an alkoxy group such as n-butylcellosolve.

  Examples of the carboxylic acid include organic carboxylic acids having 7 or more carbon atoms such as caprylic acid and 2-ethylhexanoic acid. Examples of aldehydes include aldehydes having 7 or more carbon atoms such as capric aldehyde and 2-ethylhexyl aldehyde.

Examples of the amine include amines having 6 or more carbon atoms such as heptylamine, octylamine, nonylamine, laurylamine, 2-ethylhexylamine.
As the catalyst component (b), the above alcohols are preferable, and ethanol, propanol, butanol, isobutanol, hexanol, 2-ethylhexanol, decanol and the like are particularly preferable.

  The amount of the magnesium compound and the catalyst component (b) used in preparing the solid adduct or the liquid magnesium compound varies depending on the type, contact conditions, etc., but the magnesium compound is the catalyst component ( It is used in an amount of 0.1 to 20 mol / liter, preferably 0.5 to 5 mol / liter per unit volume of b). Further, if necessary, a medium inert to the solid adduct can be used in combination. As said medium, a well-known hydrocarbon compound, such as heptane, octane, decane, is mentioned as a preferable example.

  The composition ratio of magnesium to the catalyst component (b) in the solid adduct or liquid magnesium compound obtained varies depending on the type of compound used, but cannot be specified unconditionally, but with respect to 1 mol of magnesium in the magnesium compound. The catalyst component (b) is preferably in the range of 2.0 mol or more, more preferably 2.2 mol or more, further preferably 2.3 mol or more, particularly preferably 2.4 mol or more and 5 mol or less. .

<Catalyst component (c)> (Aromatic carboxylic acid ester and / or compound having two or more ether bonds via a plurality of carbon atoms)
The solid titanium catalyst component (I) is further an aromatic carboxylic acid ester and / or a compound having two or more ether bonds via a plurality of carbon atoms (hereinafter also referred to as “catalyst component (c)”). May be included. If the solid titanium catalyst component (I) contains the catalyst component (c), the activity and stereoregularity may be enhanced, and the molecular weight distribution may be further broadened.

Examples of the catalyst component (c) include known aromatic carboxylic acid esters and polyether compounds that are preferably used in conventional olefin polymerization catalysts, such as those disclosed in JP-A-5-170843.
And the compounds described in JP 2001-354714 A and the like can be used without limitation.

Specific examples of the aromatic carboxylic acid ester include aromatic polycarboxylic acid esters such as phthalic acid esters, in addition to aromatic carboxylic acid monoesters such as benzoic acid esters and toluic acid esters. Among these, aromatic polycarboxylic acid esters are preferable, and phthalic acid esters are more preferable. As the phthalates, phthalic acid alkyl esters such as ethyl phthalate, n-butyl phthalate, isobutyl phthalate, hexyl phthalate and heptyl phthalate are preferable, and diisobutyl phthalate is particularly preferable.

  More specifically, examples of the polyether compound include compounds represented by the following formula (3).

In the above formula (3), m is an integer of 1 ≦ m ≦ 10, more preferably an integer of 3 ≦ m ≦ 10, and R ^{11 to} R ³⁶ are each independently a hydrogen atom, carbon, hydrogen ,oxygen,
A substituent having at least one element selected from fluorine, chlorine, bromine, iodine, nitrogen, sulfur, phosphorus, boron and silicon.

When m is 2 or more, a plurality of R ¹¹ and R ¹² may be the same or different. Arbitrary R ^{11 to} R ³⁶ , preferably R ¹¹ and R ¹² may jointly form a ring other than a benzene ring.

Some specific examples of such compounds include:
2-isopropyl-1,3-dimethoxypropane,
2-s-butyl-1,3-dimethoxypropane,
Monosubstituted dialkoxypropanes such as 2-cumyl-1,3-dimethoxypropane;
2-isopropyl-2-isobutyl-1,3-dimethoxypropane,
2,2-dicyclohexyl-1,3-dimethoxypropane,
2-methyl-2-isopropyl-1,3-dimethoxypropane,
2-methyl-2-cyclohexyl-1,3-dimethoxypropane,
2-methyl-2-isobutyl-1,3-dimethoxypropane,
2,2-diisobutyl-1,3-dimethoxypropane,
2,2-bis (cyclohexylmethyl) -1,3-dimethoxypropane,
2,2-diisobutyl-1,3-diethoxypropane,
2,2-diisobutyl-1,3-dibutoxypropane,
2,2-di-s-butyl-1,3-dimethoxypropane,
2,2-dineopentyl-1,3-dimethoxypropane,
2-isopropyl-2-isopentyl-1,3-dimethoxypropane,
2-substituted dialkoxypropanes such as 2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane
2,3-dicyclohexyl-1,4-diethoxybutane,
2,3-dicyclohexyl-1,4-diethoxybutane,
2,3-diisopropyl-1,4-diethoxybutane
2,4-diphenyl-1,5-dimethoxypentane,
2,5-diphenyl-1,5-dimethoxyhexane,
2,4-diisopropyl-1,5-dimethoxypentane,
2,4-diisobutyl-1,5-dimethoxypentane,
Dialkoxyalkanes such as 2,4-diisoamyl-1,5-dimethoxypentane,
2-methyl-2-methoxymethyl-1,3-dimethoxypropane,
2-cyclohexyl-2-ethoxymethyl-1,3-diethoxypropane,
Trialkoxyalkanes such as 2-cyclohexyl-2-methoxymethyl-1,3-dimethoxypropane,
2,2-diisobutyl-1,3-dimethoxy-4-cyclohexene,
2-isopropyl-2-isoamyl-1,3-dimethoxy-4-cyclohexene,
2-cyclohexyl-2-methoxymethyl-1,3-dimethoxy-4-cyclohexene,
2-isopropyl-2-methoxymethyl-1,3-dimethoxy-4-cyclohexene,
2-isobutyl-2-methoxymethyl-1,3-dimethoxy-4-cyclohexene,
2-cyclohexyl-2-ethoxymethyl-1,3-dimethoxy-4-cyclohexene,
2-isopropyl-2-ethoxymethyl-1,3-dimethoxy-4-cyclohexene,
Examples thereof include dialkoxycycloalkanes such as 2-isobutyl-2-ethoxymethyl-1,3-dimethoxy-4-cyclohexene.

  Of these, 1,3-diethers are preferred, and in particular, 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl. 1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, and 2,2-bis (cyclohexylmethyl) 1,3-dimethoxypropane are preferred.

These compounds may be used individually by 1 type, and may be used in combination of 2 or more type.
The cyclic ester compound (a), the catalyst component (b), and the catalyst component (c) as described above may be considered to belong to a component called an electron donor by those skilled in the art. The above-mentioned electron donor component has the effect of increasing the stereoregularity of the resulting polymer while maintaining the high activity of the catalyst, the effect of controlling the composition distribution of the resulting copolymer, the particle shape of the catalyst particles, It is known to show an aggregating agent effect for controlling the particle size.

It is considered that the cyclic ester compound (a) is an electron donor, and thus has an effect of controlling the molecular weight distribution.
In the solid titanium catalyst component (I), the halogen / titanium (atomic ratio) (that is, the number of moles of halogen atoms / the number of moles of titanium atoms) is 2 to 100, preferably 4 to 90,
The cyclic ester compound (a) / titanium (molar ratio) (that is, the number of moles of the cyclic ester compound (a) / the number of moles of titanium atoms) is 0.01 to 100, preferably 0.2 to 10. Desirable,
In the catalyst component (b) and the catalyst component (c), the catalyst component (b) / titanium atom (molar ratio) is 0 to 100, preferably 0 to 10, and the catalyst component (c) / titanium atom ( The molar ratio is 0-100, preferably 0-10.

Magnesium / titanium (atomic ratio) (that is, the number of moles of magnesium atoms / the number of moles of titanium atoms) is 2 to 100, preferably 4 to 50.
The content of components other than the cyclic ester compound (a) described above, for example, the catalyst component (b) and the catalyst component (c) is preferably 100% by weight of the cyclic ester compound (a). It is 20 weight% or less, More preferably, it is 10 weight% or less.

As a more detailed preparation condition of the solid titanium catalyst component (I), except that the cyclic ester compound (a) is used, for example, as described in EP585869A1 (European Patent Application Publication No. 0585869), Patent Document 2 and the like Conditions can be preferably used.

・ Organometallic compound catalyst component (II)
As the organometallic compound catalyst component (II), a compound containing a Group 13 metal, for example, an organoaluminum compound, a complex alkylated product of a Group 1 metal and aluminum, an organometallic compound of a Group 2 metal, or the like is used. it can. Among these, an organoaluminum compound is preferable.

Specific examples of the organometallic compound catalyst component (II) include organometallic compound catalyst components described in publicly known documents such as EP585869A1.
・ Electron donor (III)
The catalyst for olefin polymerization suitably used in the present invention may contain an electron donor (III) as necessary together with the organometallic compound catalyst component (II). The electron donor (III) is preferably an organosilicon compound. Examples of the organosilicon compound include a compound represented by the following general formula (4).

R _n Si (OR ′) _4-n (4)
(In the formula, R and R ′ are hydrocarbon groups, and n is an integer of 0 <n <4.)
Specific examples of the organosilicon compound represented by the general formula (4) include diisopropyldimethoxysilane, t-butylmethyldimethoxysilane, t-butylmethyldiethoxysilane, t-amylmethyldiethoxysilane, Dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, t-butyltriethoxysilane, phenyltriethoxysilane, cyclohexyltrimethoxysilane, cyclopentyltrimethoxysilane, 2-methyl Cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane, tricyclopentylmethoxysilane, dicyclo Lopentylmethylmethoxysilane, dicyclopentylethylmethoxysilane, cyclopentyldimethylethoxysilane and the like are used.

  Of these, vinyltriethoxysilane, diphenyldimethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, and dicyclopentyldimethoxysilane are preferably used.

In addition, a silane compound represented by the following formula (5) described in International Publication No. 2004/016662 pamphlet is also a preferable example of the organosilicon compound.
Si (OR ^a ) ₃ (NR ^b R ^c ) (5)
In the formula (5), R ^a is a hydrocarbon group having 1 to 6 carbon atoms, and examples of ^Ra include an unsaturated or saturated aliphatic hydrocarbon group having 1 to 6 carbon atoms, particularly preferably. A C2-C6 hydrocarbon group is mentioned. Specific examples include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, n-pentyl group, iso-pentyl group, cyclopentyl group, n- A hexyl group, a cyclohexyl group, etc. are mentioned, Among these, an ethyl group is particularly preferable.

In formula (5), R ^b is a hydrocarbon group having 1 to 12 carbon atoms or hydrogen, and examples of R ^b include an unsaturated or saturated aliphatic hydrocarbon group having 1 to 12 carbon atoms or hydrogen. . Specific examples include a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, an n-pentyl group, an iso-pentyl group, and a cyclopentyl group. , N-hexyl group, cyclohexyl group, octyl group and the like, among which ethyl group is particularly preferable.

In Formula (5), R ^c is a hydrocarbon group having 1 to 12 carbon atoms, and examples of R ^c include an unsaturated or saturated aliphatic hydrocarbon group having 1 to 12 carbon atoms or hydrogen. Specific examples include methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, sec-butyl group, n-pentyl group, iso-pentyl group, cyclopentyl group, n- A hexyl group, a cyclohexyl group, an octyl group, etc. are mentioned, Among these, an ethyl group is particularly preferable.

Specific examples of the compound represented by the above formula (5) include
Dimethylaminotriethoxysilane,
Diethylaminotriethoxysilane,
Diethylaminotrimethoxysilane,
Diethylaminotriethoxysilane,
Diethylaminotri-n-propoxysilane,
Di-n-propylaminotriethoxysilane,
Methyl n-propylaminotriethoxysilane,
t-butylaminotriethoxysilane,
Ethyl n-propylaminotriethoxysilane,
Ethyl iso-propylaminotriethoxysilane,
Mention may be made of methylethylaminotriethoxysilane.

Another example of the organosilicon compound is a compound represented by the following formula (6).
RNSi (OR ^a ) ₃ (6)
In the formula (6), RN represents a cyclic amino group. Examples of the cyclic amino group include a perhydroquinolino group, a perhydroisoquinolino group, a 1,2,3,4-tetrahydroquinolino group, 2,3,4-tetrahydroisoquinolino group, octamethyleneimino group and the like can be mentioned. Specifically as a compound represented by the said Formula (6),
(Perhydroquinolino) triethoxysilane,
(Perhydroisoquinolino) triethoxysilane,
(1,2,3,4-tetrahydroquinolino) triethoxysilane,
(1,2,3,4-tetrahydroisoquinolino) triethoxysilane,
Examples include octamethyleneiminotriethoxysilane.

These organosilicon compounds can be used in combination of two or more.
Other useful compounds as the catalyst component (III) include the aromatic carboxylic acid ester and / or a compound having two or more ether bonds via a plurality of carbon atoms (the catalyst component (c)). The polyether compounds described as examples are also preferred examples.

Among these polyether compounds, 1,3-diethers are preferred, and in particular, 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2-isopropyl 2-Isopentyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, and 2,2-bis (cyclohexylmethyl) 1,3-dimethoxypropane are preferred.

These compounds can be used alone or in combination of two or more.
The olefin polymerization catalyst may contain other components useful for olefin polymerization as required in addition to the above components. Examples of other components include inorganic oxide carriers such as silica, antistatic agents, particle aggregating agents, storage stabilizers, and the like. However, when using the resin obtained from the said catalyst for olefin polymerization as a capacitor film material, it is preferable not to use inorganic oxides, such as a silica, as much as possible.

Production method of polypropylene resin The polypropylene resin used in the present invention is obtained by polymerizing polypropylene alone in the presence of the olefin polymerization catalyst, or propylene and a small amount of ethylene or an α-olefin having 4 to 20 carbon atoms. It can be suitably produced depending on whether it is copolymerized with. In the present invention, “polymerization” may include the meaning of copolymerization such as random copolymerization and block copolymerization in addition to homopolymerization.

The polypropylene resin according to the present invention can be polymerized in the presence of a prepolymerization catalyst obtained by prepolymerization of an α-olefin in the presence of the olefin polymerization catalyst. . This prepolymerization is performed by prepolymerizing α-olefin in an amount of 0.1 to 1000 g, preferably 0.3 to 500 g, particularly preferably 1 to 200 g, per 1 g of the olefin polymerization catalyst.

In the prepolymerization, a catalyst having a higher concentration than the catalyst concentration in the system in the main polymerization can be used.
The concentration of the solid titanium catalyst component (I) in the prepolymerization is usually about 0.001 to 200 mmol, preferably about 0.01 to 50 mmol, particularly preferably 0, in terms of titanium atom per liter of the liquid medium. Desirably, the range is from 1 to 20 mmol.

  The amount of the organometallic compound catalyst component (II) in the prepolymerization should be such that 0.1 to 1000 g, preferably 0.3 to 500 g of polymer is produced per 1 g of the solid titanium catalyst component (I). The amount is usually about 0.1 to 300 mol, preferably about 0.5 to 100 mol, particularly preferably 1 to 50 mol, per mol of titanium atom in the solid titanium catalyst component (I). Is desirable.

  In the prepolymerization, the catalyst component (III) or the like can be used as necessary. In this case, these components are added in an amount of 0.1 to 50 per mole of titanium atom in the solid titanium catalyst component (I). It is used in an amount of mol, preferably 0.5 to 30 mol, more preferably 1 to 10 mol.

The prepolymerization can be performed under mild conditions by adding an olefin and the above catalyst components to an inert hydrocarbon medium.
In this case, as the inert hydrocarbon medium used, specifically,
Aliphatic hydrocarbons such as propane, butane, pentane, hexane, heptane, octane, decane, dodecane, kerosene;
Cycloaliphatic hydrocarbons such as cycloheptane, cycloheptane, methylcycloheptane, 4-cycloheptane, 4-cycloheptane, methyl 4-cycloheptane;
Aromatic hydrocarbons such as benzene, toluene, xylene;
Halogenated hydrocarbons such as ethylene chloride and chlorobenzene,
Alternatively, a mixture thereof can be used.

  Of these inert hydrocarbon media, it is particularly preferable to use aliphatic hydrocarbons. Thus, when using an inert hydrocarbon medium, it is preferable to perform prepolymerization by a batch type.

  On the other hand, the prepolymerization can be carried out using the olefin itself as a solvent, or the prepolymerization can be carried out in a substantially solvent-free state. In this case, it is preferable to perform preliminary polymerization continuously.

The olefin used in the prepolymerization may be the same as or different from the olefin used in the main polymerization described later. Specifically, propylene is preferable.
The temperature during the prepolymerization is usually within the range of about -20 to + 100 ° C, preferably about -20 to + 80 ° C, more preferably 0 to + 40 ° C.

Next, the main polymerization carried out after passing through the pre-polymerization or without going through the pre-polymerization will be described.
In the main polymerization (polymerization), propylene can be polymerized or copolymerized alone, or propylene with ethylene or an α-olefin having 4 to 20 carbon atoms. Examples of the α-olefin having 4 to 20 carbon atoms include 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like can be mentioned. Among these, ethylene or an α-olefin having 4 to 10 carbon atoms is preferable. In addition, aromatic vinyl compounds such as styrene and allylbenzene; alicyclic vinyl compounds such as vinylcyclohexane and vinylcycloheptane can also be used. In addition, compounds with polyunsaturated bonds such as conjugated dienes and non-conjugated dienes such as dienes such as cyclopentene, cycloheptene, norbornene, tetracyclododecene, isoprene and butadiene, together with ethylene and α-olefins are part of the polymerization raw material. Can also be used. These compounds may be used individually by 1 type, and may use 2 or more types together. In the monomer, the content of copolymerization components other than propylene is 10 mol% or less, preferably 5 mol% or less, more preferably 2 mol% or less.

In the present invention, the prepolymerization and the main polymerization can be carried out by any of a liquid phase polymerization method such as a bulk polymerization method, a solution polymerization and a suspension polymerization, or a gas phase polymerization method.
When the main polymerization takes the form of slurry polymerization, the reaction solvent can be an inert hydrocarbon used during the above-mentioned prepolymerization, or an olefin that is liquid at the reaction temperature.

In the main polymerization, the solid titanium catalyst component (I) is usually about 0.0001 to 0.5 mmol, preferably about 0.005, in terms of titanium atoms per liter of polymerization volume.
Used in an amount of ˜0.1 mmol. The organometallic compound catalyst component (II) is usually about 1 to 2000 mol in terms of metal atoms in the catalyst component (II) with respect to 1 mol of titanium atoms in the prepolymerized catalyst component in the polymerization system. The amount is preferably about 5 to 500 mol. If the catalyst component (III) is used, it is 0.001 to 50 mol, preferably 0.01 to 30 mol, relative to 1 mol of the metal atom in the organometallic compound catalyst component (II). Particularly preferably, it is used in an amount of 0.05 to 20 mol.

If the main polymerization is carried out in the presence of hydrogen, the molecular weight of the resulting polymer can be adjusted, and a polypropylene resin having a high melt flow rate can be obtained.
In the main polymerization, the polymerization temperature is usually about 20 to 200 ° C, preferably about 30 to 100 ° C, more preferably 50 to 90 ° C. The pressure is usually set to normal pressure to 100 kgf / cm ² (9.8 MPa), preferably about ^{2 to} 50 kgf / cm ² (0.20 to 4.9 MPa). In the method for producing a polypropylene resin, the polymerization can be carried out by any of batch, semi-continuous and continuous methods. Furthermore, the polymerization can be carried out in two or more stages by changing the reaction conditions. By performing such multistage polymerization, the molecular weight distribution of the polypropylene resin can be further expanded, that is, the Mw / Mn value, Mz / Mw value, and Mz / Mn value can be further increased.

The polypropylene resin thus obtained may be any of a homopolymer, a random copolymer and a block copolymer.
When a polypropylene resin is produced using the olefin polymerization catalyst as described above, a highly stereoregular polypropylene resin having a decane insoluble component content of 70% or more, preferably 85% or more, particularly preferably 90% or more. Is obtained.

  Furthermore, in the method for producing a polypropylene resin, a polyolefin having a wide molecular weight distribution, particularly polypropylene, can be obtained without performing multi-stage polymerization or by polymerization with a small number of stages, for example, single-stage polymerization. In the method for producing the polypropylene resin, in particular, the ratio of the component having a higher molecular weight is higher than that of the conventional olefin polymer having the same melt flow rate (MFR), and (especially called a solid component). ) In many cases, a polypropylene resin having a low ratio of components having a low molecular weight is obtained. This feature can be confirmed by gel permeation chromatography (GPC) measurement described later, and a polypropylene resin having both a high Mw / Mn value and a high Mz / Mw value can be obtained.

Polypropylene obtained by using a conventional solid titanium catalyst component containing magnesium, titanium, halogen and an electron donor is an index of molecular weight distribution obtained by GPC measurement, for example, in a region where MFR is 1 to 10 g / 10 min. In general, the Mw / Mn value was 5 or less and the Mz / Mw value was less than 4, but when the method for producing a polypropylene resin was used, the Mw / Mn value was 6 to 6 under the same polymerization conditions as described above. A polypropylene resin of 30, preferably 7-20, more preferably 8-18 can be obtained. Further, a polypropylene resin having an Mz / Mw value of 4 to 15, more preferably 4.5 to 15, and further preferably 5 to 10 can be obtained. Further, the Mz / Mn value of the olefin polymer used in the present invention is preferably 25 or more, more preferably 30 or more, and particularly preferably 40 or more. The upper limit of the Mz / Mn value is preferably 300, more preferably 250, and particularly preferably 200. In particular, in the method for producing the polypropylene resin, a polymer having a high Mz / Mw value and Mz / Mn value is often obtained.

  Polypropylene having a high Mw / Mn value is commonly known to those skilled in the art to be excellent in moldability and rigidity. On the other hand, a high Mz / Mw value indicates a high content ratio of components having a high molecular weight, which is considered advantageous for the formation of β crystals.

  Other methods for obtaining a polypropylene resin having a broad molecular weight distribution include melt mixing and melt kneading of polypropylene resins having different molecular weights, but the polypropylene resin obtained by these methods is relatively complicated. May not be sufficiently improved in melt tension and moldability. This is presumably because polypropylene resins having different molecular weights are basically difficult to mix.

  On the other hand, the polypropylene resin obtained by the method for producing a polypropylene resin has a high content ratio of components having a high molecular weight, as can be seen from the fact that the Mz / Mw value and Mz / Mn value are high without performing multistage polymerization. It is considered that the polypropylene resin component having a high molecular weight is dispersed at the catalyst level, that is, at the nano level. Therefore, it is considered that the β crystals formed are small, and therefore the number is large, and the uniformity is further increased.

  In the method for producing a polypropylene resin, since a polypropylene resin having a wide molecular weight distribution can be obtained without performing multistage polymerization, there is a possibility that the polymer production apparatus can be further simplified. In addition, when applied to the conventional multistage polymerization method, the molecular weight distribution can be further expanded, so that further improvement in performance is expected.

  If necessary, other polymers such as other resins or rubber may be added to the polypropylene film constituting the capacitor film raw sheet and film of the present invention within a range not impairing the object of the present invention. Good. Examples of the other resin or rubber include poly α-olefins such as polyethylene, polybutene-1, polyisobutene, polypentene-1, and polymethylpentene-1, ethylene / propylene copolymers having a propylene content of less than 75% by weight, Ethylene or α-olefin / α-olefin copolymer such as ethylene / butene-1 copolymer, propylene / butene-1 copolymer having a propylene content of less than 75% by weight; propylene content of less than 75% by weight Ethylene such as ethylene / propylene / 5-ethylidene-2-norbornene copolymer or α-olefin / α-olefin / diene monomer copolymer; vinyl monomer / diene monomer such as styrene / butadiene random copolymer Random copolymer; styrene / butadiene / styrene block copolymer Vinyl monomer / diene monomer / vinyl monomer block copolymer; hydrogenation (styrene / butadiene random copolymer) and other hydrogenation (vinyl monomer / diene monomer random copolymer) Hydrogenation (vinyl monomer / diene monomer / vinyl monomer block copolymer) and the like such as hydrogenation (styrene / butadiene / styrene block copolymer).

The amount of such other polymer added varies depending on the type of resin to be added or the type of rubber and may be in a range that does not impair the purpose of the present invention, but is usually about 5% by weight with respect to 100 parts by weight of the polypropylene resin. Part or less.

  Various additives may be added to the polypropylene resin constituting the original film for capacitor film and the film of the present invention as required. As the additive, any known additive that can be blended into the polypropylene resin can be used as long as the object of the present invention is not impaired. For example, an antioxidant, an ultraviolet absorber, a metal soap, a hydrochloric acid absorber, and the like. Stabilizers, lubricants, plasticizers, flame retardants, antistatic agents and the like can be used.

  The olefin polymer used in the present invention is characterized by containing a relatively large amount of high molecular weight components as described above. It is known that high molecular weight components tend to be cut relatively easily due to energy such as heat, light and shear. When molecular cutting occurs, the molecular weight distribution becomes narrow, which may cause problems such as a reduction in high-speed molding performance and difficulty in manufacturing a large molded product. Therefore, it is preferable to select an additive having a higher effect than the conventional additive or increase the amount of the additive.

  On the other hand, the capacitor film raw sheet of the present invention or the polypropylene resin used in the present invention does not contain slip agents, anti-blocking agents, nucleating agents, etc., since the electrical insulation properties may decrease. Is preferred.

Capacitor Film Original Sheet and Film The capacitor film original sheet of the present invention is obtained by extrusion-molding the above-described polypropylene resin. The extrusion molding of the capacitor film raw sheet of the present invention can be suitably performed by heating and kneading the polypipropylene resin and extruding it from a T die. It can perform more suitably by gradually cooling with the cooling roll hold | maintained at temperature.

  For example, in the production of the original sheet for capacitor film of the present invention, the above-described specific polypropylene resin is heated and melted at 170 to 280 ° C., preferably 190 to 230 ° C., with an extruder, and is formed into a sheet form from the tip T die. A method of forming a sheet by extruding and cooling and solidifying through one or a plurality of cooling rolls can be adopted. When cooling, the temperature of the roll group is 60 ° C. or higher, preferably 70 ° C. or higher, more preferably 90 to 110 ° C., so that the raw sheet can be gradually cooled to form a large amount of β crystals. A sheet having a fraction of 0.20 or more can be easily obtained. Although it does not specifically limit in a cooling roll, Thickness is 0.1-3 mm by performing gradual cooling with the pulling speed of 0.2-3 m / min and the cooling time by a cooling roll of 0.3-4.5 minutes. It is preferable to obtain the sheet.

  The raw sheet for capacitor film of the present invention has a β crystal fraction of 0.20 or more, a preferable lower limit value is 0.25, more preferably 0.30, still more preferably 0.40. On the other hand, the preferred upper limit is 0.60, preferably 0.50. This β crystal fraction is a value of a polypropylene resin not containing a β crystal nucleating agent. The slow cooling is performed at a pulling speed of 0.2 to 3 m / min and a cooling time of 0.3 to 4.5 minutes with a cooling roll so that the thickness of the sheet passed through the cooling roll is 0.1 to 3 mm. Is desirable.

In the present invention, the β crystal fraction can be made 0.20 or more by using the polypropylene resin having the specific physical properties. In the polypropylene resin having the specific physical properties, the melt flow rate is wide, and it is considered that the high molecular weight component is large and finely dispersed. Therefore, the high molecular weight component acts efficiently as a nucleating agent, and the β crystal fraction is high. It is considered that a sheet of 0.20 or more can be easily produced. Moreover, the β crystal fraction of the sheet can be made higher by the molding conditions under which the specific cooling is performed. When this is stretched, the film becomes hazy, and the film surface has sufficient irregularities and excellent anti-blocking properties, and the surface irregularities as a capacitor film can be sufficiently satisfied.

  Since the polypropylene resin preferably used in the present invention is considered to have a high molecular weight component finely dispersed, it has a large number of β crystals and is advantageous for surface irregularity. In addition, when the β crystal number is the same as that of the conventional product, the β crystal size is considered to be small when the β crystal fraction is the same as that of the conventional product.

  The β crystal is one type of crystal form of the polypropylene resin, and has a lower melting point and lower density than the most stable α crystal polypropylene resin. Further, since the density is lower than that of the α-crystal polypropylene resin, irregularities are generated on the film surface when the β-crystal is transformed into the α-crystal by an external pressure such as stretching.

The β crystal fraction in the present invention is A.S. Turner Jones et al, Macrom
ol. Chem. , 75, 134 (1964), and is sometimes referred to as a K value. That is, the value is obtained from the following formula based on the diffraction intensity obtained by performing X-ray diffraction on the sheet.

(In the above formula, Hβ ₁ corresponds to the height (intensity) of the peak corresponding to the scattering of the crystal part of the β crystal (2θ = 16 ° peak), and Hα ₁ corresponds to the scattering of the crystal part of the α crystal (110). Peak height (intensity)
, Hα ₂ is the height (intensity) of the peak corresponding to the scattering of the crystal part of the α crystal (040), and Hα ₃ is the height (intensity) of the peak corresponding to the scattering of the crystal part of the α crystal (130). . However, any value is the peak height after subtracting the scattering of the amorphous part. )
Here, the conditions of X-ray diffraction are as follows.

X-ray: Cu, Kα, 50 kV, 300 mA
Cu target, point focus, transmission method, sample rotation method Scattering slit: 1 deg
Receiving slit: 0.3mm
Scanning mode: Continuous Scanning speed: 2 ° / min
Scan width: 2θ
The raw sheet for capacitor film of the present invention or the capacitor film of the present invention has an ash content of 50 ppm or less, preferably 30 ppm or less. When the ash content is 50 ppm or less, the electrical insulation is excellent, and therefore the performance as a capacitor film raw sheet or capacitor film is excellent. Such a polypropylene resin having a low ash content can be produced by using a highly active catalyst, or by decomposing and / or removing the catalyst in the polymerized polypropylene resin. In the raw sheet for capacitor film of the present invention or the capacitor film of the present invention, the ash content of the polypropylene resin constituting these is the above concentration, and the chlorine content is 10 ppm or less, preferably 5 ppm or less. It is preferable that the influence on the characteristics of the capacitor component can be minimized.

Any known method can be employed as a method for decomposing and / or removing the catalyst. Specifically, a method of washing the polypropylene resin with liquid propylene can be mentioned. Moreover, the method of wash | cleaning polypropylene resin using alcohols, such as isobutyl alcohol, and carbonyl compounds, such as acetylacetone, is also mentioned. These methods are preferably carried out in a propylene gas atmosphere or an inert gas atmosphere such as nitrogen without being exposed to the outside air after propylene polymer particles are produced by polymerization of propylene.

  The raw sheet for capacitor film of the present invention has a high β crystal fraction, and preferably has a β crystal fraction of 0.20 or more, and therefore can be suitably used as a polypropylene film such as a matte film or a capacitor film. On the other hand, it also has a unique property that is relatively excellent in transparency.

  The thickness of the capacitor film raw sheet of the present invention can be appropriately selected depending on the application and is not particularly limited, but is usually 0.1 to 3 mm, preferably 0.3 to 1 mm. desirable. The raw film sheet for a capacitor film of the present invention can be further subjected to stretching treatment as necessary to obtain a stretched film.

  The raw sheet for capacitor film of the present invention is stretched and used as a material for a capacitor film. Stretching can be performed by a known method such as stretching roll and / or tenter stretching or tubular stretching, usually by reheating the film to a temperature between 100 ° C. and melting point. Stretching can be performed by uniaxial stretching or biaxial stretching. In the case of biaxial stretching, the stretching ratio is about 3 to 7 times in length and about 3 to 11 times in width. By this stretching treatment, a film having excellent mechanical strength and rigidity, a large number of surface irregularities, and a roughened surface can be produced.

  From the polypropylene resin according to the present invention, a sheet containing many β crystals having a β crystal fraction of 0.20 or more is obtained. In addition to the film properties (rigidity, thermal shrinkage, dimensional stability, etc.), the polypropylene resin according to the present invention can be easily manufactured without blending a β crystal nucleating agent with a high anti-blocking property. can do.

  The raw sheet for capacitor film of the present invention is particularly suitable as a raw sheet for capacitor film because it has excellent electrical insulation properties when the ash content is 50 ppm or less and the chlorine content is 10 ppm or less. . When it is stretched, preferably biaxially stretched, the number of surface irregularities is large and the surface is roughened, so the antiblocking effect is excellent. A stretched film with excellent electrical insulation properties, many surface irregularities, excellent anti-blocking effects, and excellent film properties (rigidity, thermal shrinkage, dimensional stability, etc.) is suitable as a capacitor film for capacitors. Can be used. Although the thickness of a capacitor film is not limited, Usually, it is 2-100 micrometers, Preferably it is 4-50 micrometers.

EXAMPLES Hereinafter, the present invention will be described more specifically based on examples, but the present invention is not limited to these examples.

In the following examples, each physical property value of the propylene polymer was measured by the following method.
(1) Bulk specific gravity:
It measured according to JIS K-6721.

(2) Melt flow rate (MFR):
Based on ASTM D1238E, it was measured with a 2.16 kg load. The measurement temperature was 230 ° C. for the propylene polymer and 260 ° C. for the 4-methyl 1-pentene polymer.

(3) Intrinsic specific viscosity ([η]):
The polymer particles were dissolved in decalin and measured according to a conventional method in decalin at a temperature of 135 ° C.
(4) Amount of decane soluble (insoluble) component:
About 3 grams of propylene polymer (measured to a unit of 10 ^-4 grams. This weight was expressed as b (grams) in the following formula), 500 ml of decane, and soluble in decane. A small amount of a heat-resistant stabilizer was charged, and the mixture was heated to 150 ° C. in 2 hours while stirring with a stirrer in a nitrogen atmosphere to dissolve the propylene polymer. Slowly cooled to ° C. The liquid containing the resulting propylene polymer precipitate was filtered under reduced pressure using a 25G-4 standard glass filter manufactured by Iwata Glass Co., Ltd. 100 ml of the filtrate was collected and dried under reduced pressure to obtain a part of the decane-soluble component, and this weight was measured to the unit of 10 ⁻⁴ grams (this weight was expressed as a (gram) in the following equation). .) After this operation, the amount of decane soluble component was determined by the following formula.

Decane-soluble component content = 100 × (500 × a) / (100 × b)
Decane-insoluble component content = 100−100 × (500 × a) / (100 × b)
(5) Molecular weight distribution:
Liquid chromatograph: Waters ALC / GPC 150-C plus type (with suggested refractometer detector)
Column: Two GMH6-HT and two GMH6-HTL manufactured by Tosoh Corporation were connected in series.

Mobile phase medium: o-dichlorobenzene Flow rate: 1.0 ml / min Measurement temperature: 140 ° C.
Method for preparing calibration curve: Sample concentration using standard polystyrene sample: 0.10% (W / W)
Sample solution volume: 500 μl
Mw / Mn value and Mz / Mw value were calculated by analyzing the obtained chromatogram by a known method. The measurement time per sample was 60 minutes.

(6) β crystal fraction:
A. Turner Jones et al, Macromol. Chem. , 75
, 134 (1964). That is, as a sample sheet, polypropylene resin was heated and melted at 200 ° C., extruded from a T-die, and with a single cooling roll maintained at a temperature of 95 ° C., a pulling speed of 1.0 m / min and a cooling time by a cooling roll of 0 .Slow cooling under the condition of 94 minutes, and a sheet having a thickness of 0.5 mm passed through a cooling roll was used. The sheet was subjected to X-ray diffraction under the above conditions, and calculated from the formula 1.

(7) Ash content:
The pellet was placed in a crucible and completely burned, and the crucible was incinerated in an electric furnace at 800 ° C. for 2 hours. The ash remaining in the crucible was measured to determine the ash content (ppm).

(8) Chlorine content:
0.8 g of polypropylene resin was burned at 400-900 ° C. in an argon / oxygen stream with a combustion apparatus manufactured by Mitsubishi Kasei Co., Ltd., and the sample gas after collecting and concentrating the combustion gas with ultrapure water was added to Nippon Dioneck ( It measured using the anion column AS4A-SC (made by Dioness) using the DIONEX-DX300 type | mold ion chromatograph measuring apparatus.

(9) Haze:
It calculated | required according to JISK7105.
(10) Fish eye analysis:
A 50 μm film was formed with a 25 mmφ T-die molding machine, and the fish eyes were visually observed. Fish eyes with a diameter of 200 μm or more were visually counted and calculated as the number per unit area.

  As the compound corresponding to the cyclic ester compound (a) of the present invention, Azuma Co., Ltd. synthetic product was used unless otherwise specified. The isomer purity of the trans isomer and cis isomer is 95% or more unless otherwise specified.

[Example 1]
(Preparation of solid titanium catalyst component (α1))
A high-speed stirring apparatus (made by Tokushu Kika Kogyo Co., Ltd.) having an internal volume of 2 liters was sufficiently purged with nitrogen, and then 700 ml of purified decane, 10 g of commercially available magnesium chloride, 24.2 g of ethanol, and the trade name Leodor SP-S20 (Kao Corporation) 3 g of sorbitan distearate (manufactured by sorbitan) was added, the system was heated while stirring this suspension, and the suspension was stirred at 120 ° C. and 800 rpm for 30 minutes. Next, 1 liter of purified decane that had been cooled to −10 ° C. in advance was put into this suspension using a Teflon (registered trademark) tube having an inner diameter of 5 mm while stirring at a high speed so as not to cause precipitation. Transferred to a 2 liter glass flask (with a stirrer). The solid produced by the transfer was filtered and washed thoroughly with purified n-heptane to obtain a solid adduct in which 2.8 mol of ethanol was coordinated with respect to 1 mol of magnesium chloride.

The above solid adduct suspended in 60 ml of decane was introduced into 400 ml of titanium tetrachloride maintained at −20 ° C., 92.4 mmol in terms of magnesium atoms, with stirring. The mixture was heated to 80 ° C. over 5 hours, and when it reached 80 ° C., diisobutyl 3,6-dimethylcyclohexane 1,2-dicarboxylate (trans form) was converted to 1 mol of magnesium atom of the solid adduct. Was added in an amount of 0.15 mol, and the temperature was raised to 120 ° C. in 40 minutes. The temperature was held at 120 ° C. with stirring for 90 minutes.

  After completion of the reaction for 90 minutes, the solid part was collected by hot filtration, and the solid part was resuspended in 200 ml of titanium tetrachloride, and then heated to 130 ° C. and stirred for 45 minutes. Hold while. After completion of the reaction for 45 minutes, the solid part was again collected by hot filtration, and sufficiently washed with decane and heptane at 100 ° C. until no free titanium compound was detected in the washing solution.

The solid titanium catalyst component (α1) prepared by the above operation was stored as a decane slurry, but a part of this was dried for the purpose of examining the catalyst composition.
(Main polymerization)
After adding 200 liters of propylene and hydrogen 550NL at room temperature to a polymerization vessel having an internal volume of 600 liters, triethylaluminum 100 mmol, cyclohexylmethyldimethoxysilane 20 mmol, and solid titanium catalyst component (α1) were converted to 0 in terms of titanium atoms. 0.8 mmol was added, and the temperature in the polymerization vessel was quickly raised to 70 ° C. After polymerization at 70 ° C. for 1 hour, the reaction was stopped with a small amount of ethanol, and propylene was purged. Thereafter, the obtained particles were put into 300 liters of heptane containing 1% isobutyl alcohol under a nitrogen stream under stirring and washing. Subsequently, solid-liquid separation was performed, and the obtained polymer particles were dried under reduced pressure at 80 ° C. overnight. (Yield: about 40kg)
The resulting polymer particles had an MFR of 3.2 g / 10 min, a decane insoluble component amount of 98.5%, a bulk specific gravity of 440 kg / m3, an Mw / Mn value as an index of molecular weight distribution of 15.7, Mz / The Mn value was 189.
(Sheet molding)
100 parts by weight of the above polymer particles, 0.3 part by weight of 3,5-di-t-butyl-4-hydroxytoluene, tetrakis [methylene-3 (3,5-di-t-butyl-4-hydroxyphenyl) ) Propionate] After blending 0.6 part by weight of methane and 0.02 part by weight of calcium stearate, it was melted at 230 ° C. and manufactured by GM Engineering Co., Ltd. GMZ50-32
(L / D = 32) Pelletized with a single screw extruder.

The obtained pellets were extruded at 200 ° C. by Nakatani Machinery Co., Ltd. VSK50 type apparatus extruder (D: 5
0mmφ) from a 600mm wide T-die and take-up speed 1 from a cooling roll held at 95 ° C
. The sheet was gradually cooled at 0 m / min, a cooling time of 0.94 minutes with a cooling roll (450 mmφ), and an air gap of 60 mm to obtain a sheet having a thickness of 0.5 mm. The sheet passed through the cooling roll was cut, and the β crystal fraction was determined using an X-ray diffractometer.
(Formation of biaxially stretched film)
The above sheet was cut into 85 mm square and biaxially stretched under the following conditions.

Stretching device: KARO IV manufactured by Bruckner
Preheating temperature: 150 ° C
Preheating time: 60 seconds Stretch ratio: Sequential stretching in MD direction 5 times, TD direction 7 times Stretching speed: 6 m / min Various measurement items such as β crystal fraction and ash content of raw sheet obtained by sheet molding The results are shown in Table 1.

[Comparative Example 1]
(Preparation of solid titanium catalyst component (β1))
A solid titanium catalyst component (β1) was obtained in the same manner as in Example 1 except that diisobutyl phthalate was used instead of diisobutyl 3,6-dimethylcyclohexane 1,2-dicarboxylate (trans form).
(Main polymerization)
After adding 200 liters of propylene and 10 liters of hydrogen at room temperature to a polymerization vessel with an internal volume of 600 liters, 100 mmol of triethylaluminum, 20 mmol of cyclohexylmethyldimethoxysilane, and solid titanium catalyst component (β1) are converted into titanium atoms. 0.8 mmol was added and the inside of the polymerization vessel was quickly heated to 70 ° C. Polymerization was carried out at 70 ° C. for 5 minutes (first stage polymerization). In addition, it was confirmed in advance that the intrinsic specific viscosity of PP obtained under these conditions was 6.2 dl / g.

Thereafter, 250 liters of hydrogen was gradually added while maintaining the temperature at 70 ° C., and then maintained for 1 hour. (Second stage polymerization)
The reaction was stopped with a small amount of ethanol and purged with propylene. Thereafter, the obtained particles were put into 300 liters of heptane containing 1% isobutyl alcohol under a nitrogen stream under stirring and washing. Subsequently, solid-liquid separation was performed, and the obtained polymer particles were dried under reduced pressure at 80 ° C. overnight. (Yield: about 50kg)
The polymer particles after completion of the second stage polymerization had an MFR of 3.0 g / 10 minutes, a decane insoluble component amount of 98.1%, and a bulk specific gravity of 440 kg / m ³ . The other results are shown in Table 1.
(Forming sheets and films)
A sheet and a biaxially stretched film were formed in the same manner as in Example 1 except that the above polymer was used.

The β crystal fraction, ash content of chlorine, etc. of the raw fabric sheet obtained by sheet molding, such as chlorine, are shown in Table 1.
[Comparative Example 2]
(Main polymerization)
After adding 200 liters of propylene to a polymerization vessel having an internal volume of 600 liters at room temperature, 100 mmol of triethylaluminum, 20 mmol of cyclohexylmethyldimethoxysilane, and 0.8 mmol of solid titanium catalyst component (β1) in terms of titanium atoms. Add
The temperature in the polymerization vessel was quickly raised to 70 ° C. After polymerization at 70 ° C. for 1 hour, propylene was purged by cooling to room temperature. (First stage polymerization)
For analysis purposes, about 10 g of the generated particles were collected under a nitrogen stream.

Subsequently, after adding 200 liters of propylene and 3000 liters of hydrogen, it heated up at 70 degreeC and hold | maintained for 1 hour. (Second stage polymerization)
The reaction was stopped with a small amount of ethanol and purged with propylene. Further, the obtained polymer particles were dried under reduced pressure at 80 ° C. overnight. (Yield: about 64kg)
From the quantification of the catalyst residue of the obtained particles, the proportion of the polymer particles obtained in the first stage polymerization was found to be 20%. [Η] of the polymer particles obtained by the first stage polymerization was 8.3 dl / g.

The polymer particles after completion of the second stage polymerization had an MFR of 2.9 g / 10 minutes, a decane insoluble component amount of 98.0%, and a bulk specific gravity of 440 kg / m ³ .
(Forming sheets and films)
A sheet and a biaxially stretched film were formed in the same manner as in Example 1 except that the above polymer was used.

  The β crystal fraction, ash content of chlorine, etc. of the raw fabric sheet obtained by sheet molding, such as chlorine, are shown in Table 1.

  As described above, the stretched sheet of the present invention is excellent in anti-blocking properties, but has a slightly low haze and less fisheye. This is not only because the molecular weight distribution is wide, but also because the high molecular weight portion is more finely dispersed, the size of β crystals produced in the middle is small, and the size of the irregularities generated during stretching is small and many. It is thought that there is a cause.

Claims (8)

The melt flow rate (MFR) measured by ASTM D-1238 (230 ° C., 2.16 kg load) is 0.5 to 10 g / 10 min, and is obtained from the measured value by gel permeation chromatography (GPC). A raw film sheet for a capacitor film obtained by extruding a polypropylene resin having an Mn value of 6 to 30 and an Mz / Mw value of 4 to 15,
The polypropylene resin has an Mz / Mn value determined from a measured value by GPC of 40 or more and 300 or less,
A solid titanium catalyst component (I) containing titanium, magnesium, halogen and a cyclic ester compound (a) specified by the following formula (1);
An organometallic compound catalyst component (II);
A raw sheet for a capacitor film, which is obtained by polymerization in the presence of an olefin polymerization catalyst containing an electron donor (III) as necessary.

[In Formula (1), n is an integer of 5-10.
R ² and R ³ are each independently COOR ¹ or R, and at least one of R ² and R ³ is COOR ¹ .
A single bond in the cyclic skeleton (excluding ^a C ^a -C ^a bond and a C ^a -C ^b bond when R ³ is R) may be replaced with a double bond.
A plurality of R ¹ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms.
A plurality of Rs are each independently an atom or group selected from a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a nitrogen-containing group, an oxygen-containing group, a phosphorus-containing group, a halogen-containing group and a silicon-containing group. And may be bonded to each other to form a ring.
The ring skeleton formed by bonding R to each other may contain a double bond. When the ring skeleton contains two or more C ^a to which COOR ¹ is bonded, The number of carbon atoms constituting the skeleton is 5-10. ]   The raw sheet for capacitor film according to claim 1, wherein at least one of R in the formula (1) is not a hydrogen atom.   The raw material for a capacitor film according to claim 1 or 2, wherein the polypropylene resin is obtained by heating and melting, extruding from a T-die, and slowly cooling with a cooling roll maintained at a temperature of 60 ° C or higher. Sheet.   3. The raw sheet for capacitor film according to claim 1, wherein the polypropylene resin is a resin obtained by one-stage polymerization.   The raw sheet for capacitor film according to claim 1, wherein the β crystal fraction is 0.20 or more. Capacitor film characterized by comprising stretching the raw sheet for a capacitor film according to claim 1 or 2. A solid titanium catalyst component (I) containing titanium, magnesium, halogen and a cyclic ester compound (a) specified by the following formula (1);
An organometallic compound catalyst component (II);
Obtained by polymerization in the presence of an olefin polymerization catalyst containing an electron donor (III) as required,
The melt flow rate (MFR) measured by ASTM D-1238 (230 ° C., 2.16 kg load) is 0.5 to 10 g / 10 min, and is obtained from the measured value by gel permeation chromatography (GPC). A polypropylene resin having an Mn value of 6 to 30, an Mz / Mw value of 4 to 15, and an Mz / Mn value of 40 or more and 300 or less,
A method for producing an original sheet for a capacitor film, characterized by heating and melting, extruding from a T-die, and gradually cooling with a cooling roll maintained at a temperature of 60 ° C or higher.

[In Formula (1), n is an integer of 5-10.
R ² and R ³ are each independently COOR ¹ or R, and at least one of R ² and R ³ is COOR ¹ .
A single bond in the cyclic skeleton (excluding ^a C ^a -C ^a bond and a C ^a -C ^b bond when R ³ is R) may be replaced with a double bond.
A plurality of R ¹ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms.
A plurality of Rs are each independently an atom or group selected from a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a nitrogen-containing group, an oxygen-containing group, a phosphorus-containing group, a halogen-containing group and a silicon-containing group. And may be bonded to each other to form a ring.
The ring skeleton formed by bonding R to each other may contain a double bond. When the ring skeleton contains two or more C ^a to which COOR ¹ is bonded, The number of carbon atoms constituting the skeleton is 5-10. ] A solid titanium catalyst component (I) containing titanium, magnesium, halogen and a cyclic ester compound (a) specified by the following formula (1);
An organometallic compound catalyst component (II);
Obtained by polymerization in the presence of an olefin polymerization catalyst containing an electron donor (III) as required,
The melt flow rate (MFR) measured by ASTM D-1238 (230 ° C., 2.16 kg load) is 0.5 to 10 g / 10 min, and is obtained from the measured value by gel permeation chromatography (GPC). A polypropylene resin having an Mn value of 6 to 30, an Mz / Mw value of 4 to 15, and an Mz / Mn value of 40 or more and 300 or less is heated and melted and extruded from a T die, and a temperature of 60 ° C. or more. A step of slowly cooling with a cooling roll held in a sheet to form a sheet,
A method for producing a capacitor film, comprising a stretching step.

[In Formula (1), n is an integer of 5-10.
R ² and R ³ are each independently COOR ¹ or R, and at least one of R ² and R ³ is COOR ¹ .
A single bond in the cyclic skeleton (excluding ^a C ^a -C ^a bond and a C ^a -C ^b bond when R ³ is R) may be replaced with a double bond.
A plurality of R ¹ are each independently a monovalent hydrocarbon group having 1 to 20 carbon atoms.
A plurality of Rs are each independently an atom or group selected from a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, a halogen atom, a nitrogen-containing group, an oxygen-containing group, a phosphorus-containing group, a halogen-containing group and a silicon-containing group. And may be bonded to each other to form a ring.
The ring skeleton formed by bonding R to each other may contain a double bond. When the ring skeleton contains two or more C ^a to which COOR ¹ is bonded, The number of carbon atoms constituting the skeleton is 5-10. ]