JP2001302820A - Film roll, method for producing the roll, and resin core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-density magnetic recording medium excellent in adhesion between a magnetic layer and a substrate and having excellent electromagnetic transducing properties, and to provide an aromatic polyamide film suitable for the medium and excellent in handleability, and to provide a film roll thereof. SOLUTION: This film roll comprises a film having >=48 dyn/cm surface wet tension, <3 nm center line surface roughness of at least one side and >=10 GPa Young's modulus, and has surface potential within the range of ±60 KV.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin film roll and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, resin films have been widely used in various fields as base materials for magnetic recording media such as video tapes, dielectrics for capacitors, and coatings for insulation.

[0003] Of these, for magnetic recording media,
With the dramatic increase in storage capacity for computer and video tapes in recent years, ultra-smoothness, defect-free,
Thinner films and higher elasticity are required. For example, Japanese Patent Application Laid-Open No.
As an example of using an aromatic polyamide film in JP 940 or the like, a specific example is shown in JP 62-62424 A or the like.

[0004]

However, the above method has the following problems. In other words, for the purpose of improving the output characteristics of the magnetic tape, an aromatic polyamide having high rigidity was used as a base to form a super-smooth surface. I have to take severe conditions. More specifically, it is necessary to wind up to a very high hardness while applying a high surface pressure and a high tension. Therefore, when the film is rewound for use, the static electricity that has accumulated between the films causes the appearance of winding defects, the deterioration of the tape quality due to poor coating of the magnetic layer, and the static electricity during handling. There is concern about discomfort and, in severe cases, spark discharge. Particularly, in the production of magnetic recording media, an organic solvent is often used, and there is a possibility of occurrence of a fire or the like. Therefore, for example, JP-A-2000-16644
As proposed in Japanese Patent Publication, there is a method of defining the winding hardness of a film roll, or a method of oscillating in the width direction at the time of winding, for example, in the case of a highly rigid film such as a polyamide film, It could not be adopted due to fear of causing poor winding appearance such as wrinkles.

[0005]

SUMMARY OF THE INVENTION The present invention has the following structure to solve such a problem. That is, a film in which the wetting tension of at least one surface is 48 dyn / cm or more, the center line surface roughness of at least one surface is less than 3 nm, and the Young's modulus is 10 GPa or more,
The present invention relates to a film roll characterized in that the surface potential of the roll is in a range of ± 60 KV. Furthermore, the present invention provides a resin film having a discharge-treated film having an E value in the range of ³ to 30 W / m ² / min. The present invention relates to a method for producing a film roll characterized by being used and wound, and to a resin core characterized by having at least one or more conductive portions and insulating portions.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

For the film of the present invention, a conventionally known organic polymer is used. For the purpose of forming a highly elastic film having a Young's modulus of 11 GPa or more, polyamide, particularly aromatic polyamide, is preferably used. Where "mainly"
Means that the content of the aromatic polyamide resin is 60 mol% or more. The above resin may be a homopolymer or a copolymer.
It may be a simple mixture of less than mol%.

Here, the aromatic polyamide comprises a repeating unit represented by the following general formula (I) and / or general formula (II) in an amount of 60 mol% or more, preferably 70 mol% or more. General formula (I)

[0009]

Embedded image General formula (II)

[0010]

Embedded image Here, Ar1, Ar2, and Ar3 are, for example,

[0011]

Embedded image And the like, X, Y is _{-O -, - CH 2 -,} - CO -, - SO 2 -, - S -, -
It is selected from C (CH ₃ ) ₂ − and the like, but is not limited thereto. Furthermore, those in which some of the hydrogen atoms on these aromatic rings are substituted with substituents such as halogen groups (particularly chlorine) such as chlorine, fluorine and bromine, nitro groups, alkyl groups and alkoxyl groups, And those in which the hydrogen in the amide bond constituting the polymer is replaced by another substituent.
Note that Ar1, Ar2, and Ar3 may be the same or different. These may be two or more copolymers or a mixture thereof. Further, an aromatic or aliphatic copolymer component other than the above may be copolymerized in a proportion of less than 50 mol%. Here, examples of the copolymerizable component include an alicyclic compound such as cyclohexylene and an aliphatic compound such as hexylene. Further, a polymer in which the above aromatic ring is bonded at the para position accounts for 50 mol% or more, preferably 75 mol% or more of the whole aromatic ring,
This is preferable because the film has a high Young's modulus and good heat resistance. If the aromatic ring in which a part of the hydrogen atoms on the aromatic ring is substituted with a halogen group (particularly chlorine) accounts for 30 mol% or more of the whole, heat resistance is improved, and properties such as dimensional change due to moisture absorption and rigidity decrease are reduced. Preferred for improvement.

Further, a lubricant, an antioxidant, an antistatic agent and other additives may be added to the film of the present invention to such an extent that physical properties are not impaired.

The film of the present invention must have a wetting tension of at least one surface of at least 48 dyn / cm. That is, in the case of a film having a wetting tension of less than 48 dyn / cm, the magnetic layer may be repelled or unevenly applied when the magnetic layer is applied in order to obtain a magnetic recording medium, or peeling may occur after application of the magnetic layer. It is. Preferably, the surface wetting tension is 50 dyn / cm or more. In order to achieve the object, specifically, a discharge treatment on the surface is suitably used. Here, the discharge treatment means any kind of corona discharge treatment or plasma discharge treatment, regardless of the atmospheric pressure, whether in the air or in a vacuum, and the atmospheric gas is air,
Nitrogen, argon, helium or mixtures thereof,
Although the type is not limited, generally, corona discharge treatment is often used in terms of simplicity of the device configuration and treatment cost. In addition, the discharge treatment may be either single-sided treatment or double-sided treatment.
At this time, the condition of the corona discharge treatment is an E value of 3 to 30 W / m.
It must be in the range of ² / min. That is, 3 W / m ² /
When the time is less than 10 minutes, the corona discharge treatment is insufficient, and the adhesiveness to the magnetic recording layer required for a magnetic recording medium cannot be obtained. On the other hand, when it is higher than 30 W / m ² / min, the film itself is deteriorated or damaged. The condition of the corona discharge treatment is preferably 3 to 20 W / m in E value.
² / min.

At least one of the films of the present invention must have an ultra-smooth surface with a center line surface roughness of less than 3 nm so as to be suitably used for a high-density magnetic recording medium. That is, when the magnetic layer is provided with a rough surface exceeding the above range, the output characteristics required for a high-density magnetic recording medium cannot be obtained. More preferably, at least one of them has a center line surface roughness of 2 nm or less. On the other hand, the other surface is preferably a rough surface having a traveling property,
Specifically, the thickness is preferably in the range of 4 to 30 nm.

The film of the present invention has a Young's modulus of 10 GP.
a must be greater than or equal to a. That is, the Young's modulus is 10G
In the case of a film having a weak "stiffness" such as less than Pa, it is difficult to make the film thinner when used for a magnetic tape, and the recording capacity per cassette cannot be increased. Here, the Young's modulus of the film needs to be 10 GPa or more in at least one direction.
Pa or more, more preferably the Young's modulus in the width direction of the film is 10 GPa or more. In addition, both the Young's modulus in the longitudinal direction and the width direction are 10 GPa.
More preferably, it is the above. The thickness of the film of the present invention is desirably a thin film, preferably from 1 to 1 for the purpose of increasing the recording capacity of the magnetic tape.
The range is 8 μm, more preferably 2 to 6 μm, and still more preferably 3 to 5 μm.

In the film roll of the present invention, the following measures are taken to prevent static electricity since the quality of the magnetic tape is maintained and the handling property is improved. In particular, the corona discharge treatment strongly charges the film. First, the surface potential of the film roll needs to be in the range of ± 60 KV. That is, ±
If it is in a strong charged state exceeding 60 KV, there is a concern that the quality of the tape is deteriorated due to poor coating of the magnetic layer, discomfort due to static electricity at the time of handling, and spark discharge is generated in severe cases. is there. Still preferably,
The surface potential is ± 50 KV, more preferably ± 40 KV. In order to achieve the above, it is effective to lower the capacitance of the “winding device”, that is, the portion including the winding core, the core receiving shaft, and the winding driving device with respect to the ground. In particular, it is particularly effective to use a resin core having at least one or more conductive portions and an insulative portion as a winding core. That is, although the resin generally used as the material of the core has an insulating property, by having a conductive portion, the capacitance with respect to the ground increases, and as a result, the surface potential of the film roll is suppressed. The volume resistance of the conductive portion is preferably less than 10 ⁹ Ωcm, more preferably less than 10 ⁷ Ωcm, and specific examples include metal, carbon, and conductive resin. On the other hand, in the case of a metal core, which is only conductive, for example, although the purpose of increasing the capacitance with respect to the ground can be achieved, there is a problem that the weight is heavy and the scratch is easily formed. Preferably, there is.

The conductive portion can be provided on the outer surface of the core by lamination, coating, pasting, or vapor deposition, or used as a core material, or by laminating, coating, pasting, or vapor deposition on the inner layer surface. . Alternatively, a method of molding by kneading in an insulating resin may also be used. In particular, it is preferable to provide a conductive portion on the outer surface or the inner surface of the core, because even if damage occurs due to contact during transportation or setting, correction becomes easy, which is preferable.
In this case, the surface resistance is more preferably less than 10 ⁷ Ω / □. Other methods that can be expected to have an effect of increasing the capacitance include grounding a resin core used for winding and using a conductive material for the touch roll. The grounding method is
It may be grounded directly or via an electric resistor.

In the film roll of the present invention, it is preferable that the surface potential of the film roll during the unwinding at a speed of 100 m / min or more and the unwinding side after the unwinding is in a range of ± 50 KV. In other words, even if the surface potential of the film roll in the stationary state is “apparently” low, even if the surface potential rises beyond the above range when rewinding during use, handling is still This is because there is a concern that discomfort or spark discharge may occur. Further, it is preferable that the surface potential of one fed film is adjusted to be in a range of ± 10 KV. That is,
Even if the surface potential of the film roll is low, if the surface potential of one film is high, quality problems due to peeling off the coating,
This is because there is concern about discomfort and spark discharge during handling. Specifically, a self-discharge type static eliminator, DC and / or
Alternatively, it is preferable to adjust the surface potential per film by using an AC needle electrode type static eliminator or an air blower type static eliminator alone, in combination, or in combination.
In this case, it is preferable to control the static elimination conditions so that at least one surface is positively or negatively charged. In other words, the side with a slight charge improves the winding shape due to the Coulomb force between the films caused by the difference in the charging polarity on the front and back, and furthermore, the contact with the transport roll by the user at the time of use by the user This is because an effect of suppressing charging and the like can be expected. In particular, it is preferable to control the charging polarity to be opposite to the charging polarity generated by the user. Further, it is preferable that the static eliminator is installed at the winding side of the film or at a place where one film is floating in the air where the film is not in contact with the roll.

The film roll of the present invention has a winding hardness of 9
It is preferable that it is 5 degrees or more. That is, in the case of a film having an ultra-smooth and high rigidity as in the present invention, when the winding hardness is as soft as less than 95 degrees,
It is not preferable because “wrinkles” occur due to a change with time. When the winding hardness is too high, the charging phenomenon described above becomes remarkable. Therefore, the upper limit is 99.9 degrees or less, which is practical and preferable.

The above-mentioned method for producing a film of the present invention is particularly applicable to an ultrathin film having a thickness of 2 to 6 μm, a length of 2,000 m or more, a width of 500 mm or more, a roll diameter of 300 mm or more, and a film. It can be effectively applied to so-called "long and wide" film rolls having a lamination thickness of only 20 mm or more. In other words, ultra-smooth, wide and long films have a weak air elimination effect at the time of winding, so conventionally, high tension and high surface pressure required that the film be hard-wound, but as a result, the effects of static electricity Because of this, the solution was craved. "Ultra-smooth" with a centerline surface roughness of 1-2 nm, especially for high density magnetic recording applications
This is effective for “ultra-ultra-thin” films having a thickness of 2 to 4 μm.

Next, the method for producing a film roll of the present invention will be described with reference to an example in which an aromatic polyamide film is used.

By a known method, for example, polymerization using an acid chloride and a diamine, a film is formed by a dry method, a dry-wet method, or a semi-dry semi-wet method using the polymer solution as a stock solution. In addition, inorganic and / or organic particles are added to the polymer solution so as to have a desired surface roughness. Further, a laminated film in which films having different surface roughness are laminated by a known method may be used. In order to improve the rigidity of the film, the film is stretched in the longitudinal direction by using a draw between rolls and in the width direction by a tenter. 2-6μ by adjusting thickness
Adjust to m. The film thus obtained is once wound up as a jumbo roll.

In order to improve the adhesiveness to the film surface, a corona discharge treatment is performed. When the film is wound around the jumbo roll, slitted to a predetermined width, or wound after being slit to a predetermined width, the winding is performed. However, it is practical and preferable to perform slitting to a predetermined width, or to perform slitting once to a predetermined width and then rewinding. The corona discharge treatment may be either one-sided treatment or two-sided treatment.

During film formation, transportation and winding,
The charge generated by the contact of the film with the stretching and the transport rolls is removed by a static eliminator.

When the product is completed after the corona discharge treatment,
It is wound around a resin core having at least one or more conductive portions and at least one insulating portion. In the slit, winding is performed by controlling the pressure of the contact pressure roll and the film tension so that the winding hardness is 95 degrees or more and less than 99.9 degrees. In this case, in order to further control the electrification, the film 1 is formed by using a self-discharge type static eliminator, a DC and / or AC needle electrode type static eliminator or an air blower type static eliminator alone, plurally or in combination. Adjust the surface potential per sheet.

The film roll thus obtained has a low surface potential at the time of unwinding, so that it has good handling properties and, when used as a base material for a magnetic recording medium, has good adhesion to a magnetic layer. And the output characteristics are also good because of its super smoothness, so that it can be used favorably for high density magnetic recording media.

The evaluation of each physical property value was performed by the following methods.

(1) Measurement of wettability of film surface Wetting index standard reagent manufactured by Nacalai Tesque (No. 45-No. 45)
No. 60) on the film surface using a cotton swab or the like,
The value was taken as the value of the surface tension of the reagent when the reagent pops out on the film.

(2) Measurement of center line surface roughness of film SPM observation system (T
appingModeAFM, NanoScopeIII
Ver. 3.25. (Trade name).

Measurement area: 5 × 5 μm Number of samples: 246 Cut off: 20 μm (3) Measurement of Young's modulus of film The film was cut into a sample having a width of 10 mm and a length of 150 mm.
The chucking speed is 100 mm and the pulling speed is 300 mm / min.
At a chart speed of 500 mm / min, the wire was pulled with an Instron type universal tensile tester, and the relationship between the elongation and the stress at that time was plotted to obtain a tangent line of a load-elongation curve at the rising portion.

(4) Film roll winding hardness Ten points were measured in the width direction using an ASKER rubber hardness meter manufactured by Kobunshi Keiki Co., Ltd., and the average value was obtained.

(5) Measurement of Surface Potential of Film and Film Roll The surface potential of the film roll and one film, and the "roll-out side" when the film roll is rewound at a speed of 200 m / min. The surface potential on the roll on the side opposite to the direction) was measured by the following method.

The surface potential up to 20 kV was measured 30 mm from the sample using a TREK electrometer MODEL523.
In the case where the distance exceeds 20 kV, the measurement was carried out at a position 50 mm away from the sample using a stachylone M2 manufactured by Shisido Electrostatics.

The surface potential on the feeding side is 7000 m
It was determined as the highest value at the time of rewinding up to.

(6) Magnetic Tape Characteristics On the magnetic surface side of the obtained film, a magnetic coating film having the following composition was applied so as to have a dried film thickness of 2 μm.・ Γ-Fe ₂ O ₃ fine powder: 200 parts by weight ・ Polyurethane resin: 30 parts by weight ・ Nitrocellulose: 10 parts by weight ・ Vinyl chloride: 10 parts by weight ・ Polyisocyanate: 5 parts by weight (solvent: methyl ethyl ketone) The obtained film after coating the magnetic layer was slit to 1/2 inch, and the following magnetic tape characteristics were evaluated at normal speed using an NV-3700 type video deck manufactured by Matsushita Electric Industrial Co., Ltd. I. VTR head output: The VTR head output at a measurement frequency of 4 MHz was measured with a synchroscope.
The value relative to the reference sample was indicated in decibels (dB). B. Dropout: A signal of 1.4 MHz was recorded, the tape was reproduced, and the number of dropouts at 15 μsec-20 dB was measured for 20 minutes with a dropout counter manufactured by Okura Industries Co., Ltd., and the number of dropouts per minute was measured. (Pieces / minute). C. Adhesion of magnetic layer: Nichiban cellophane tape was stuck and pressed firmly by hand, and then rapidly peeled in the 180-degree direction, and the following judgment was made.

-No peeling at all: ○-No peeling, but magnetic layer deformed: △-Partial peeling: ×

[0037]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
The film used for winding was manufactured by the following method.

N-methylpyrrolidone (NMP) 3200
In parts, 114 parts of 2-chloroparaphenylenediamine, 4,
Forty parts of 4-diaminophenyl ether were dissolved, and 237.5 parts of 2-chloroterephthalic acid chloride was added thereto, followed by stirring for 2 hours to carry out polymerization. This was neutralized with lithium hydroxide to obtain an aromatic polyamide solution having a polymer concentration of 10 wt% and a viscosity of 3000 poise. In this solution, spherical silica having an average particle size of 0.08 μm was made into an NMP slurry,
0.40 per polymer added to the polyamide solution
The addition amount was set to be wt%.

After the polymer solution was filtered through a filter having a filtration accuracy of 1 μm, the film was heated with hot air at 180 ° C. for 2 minutes to evaporate the solvent, and the self-supporting film was continuously peeled off from the metal belt. Next, the film was introduced into a water tank having an NMP concentration gradient, and the residual solvent and the inorganic salts generated by neutralization were subjected to water extraction. At this time, the film was stretched 1.1 times in the longitudinal direction of the film. Subsequently, the water was dried with a 240 ° C. stenter, stretched 1.4 times in the width direction, and heat-treated, and then gradually cooled to finally obtain a 3.6 μm aromatic polyamide film. After the film was once formed into a jumbo roll, it was slit into a polyester resin core having a diameter of 152.4 mm so that the width of the film roll was 1010 mm, the length was 7400 m, and the winding hardness was 98.5 degrees. The film roll was further rewound by the following method. Table 1 shows the details of the conditions. The laminated thickness of the film with respect to the resin core is 37 m.
m.

Example 1 A resin core having an outer diameter of 152.4 mm and a length of 1200 m
m, a polyester resin having glass fiber as a reinforcing material and having an outer surface coated with an epoxy conductive resin was used. The core was attached to a take-up driving device that was grounded, and was taken up while pressing the film with a contact pressure roll to obtain a film roll having a rubber hardness of 98.5 degrees. E value = 3.8W / m during winding
^A corona discharge treatment was carried out at a rate of ² / min, and after that, static elimination was appropriately performed to obtain a film roll having an average hardness of 98.5 degrees.

Example 2 Example 1 was repeated except that no epoxy conductive resin coating was applied and a polyester resin core using a reinforcing material combining glass fiber and carbon fiber was used.
A film roll was obtained in the same manner as described above.

Example 3 A film roll was obtained in the same manner as in Example 1 except that the epoxy conductive resin coat was not applied and an inner aluminum layer having a thickness of 2 mm was provided.

Example 4 A film roll was obtained in the same manner as in Example 1, except that the core was mounted on a winding drive device not grounded and wound.

Example 5 A film roll was obtained in the same manner as in Example 1 except that the static elimination method was changed and static elimination was performed using positive charges.

Example 6 In Example 1, the corona discharge treatment was performed with an E value of 3.0 W /
A film roll was obtained in the same manner as in Example 1 except that the film roll was performed at m ² / min.

Example 7 A film roll was obtained in the same manner as in Example 1 except that static elimination was performed so that the surface potential of one film became 0 kV.

Comparative Example 1 A film was obtained in the same manner as in Example 1 except that the corona discharge treatment was not performed and the winding hardness was changed to 92 degrees.

Comparative Example 2 The procedure of Example 1 was repeated, except that a polyester resin core reinforced with glass fiber having no conductive portion was used, and the film was wound by being attached to a winding drive device that was not grounded. A film was obtained in the same manner as described above.

Comparative Example 3 In 3200 parts of N-methylpyrrolidone (NMP) were dissolved 114 parts of 2-chloroparaphenylenediamine and 40 parts of 4,4-diaminophenyl ether, and 237.5 parts of 2-chloroterephthalic acid chloride was added thereto. Was added and stirred for 2 hours to carry out polymerization. This was neutralized with lithium hydroxide to obtain an aromatic polyamide solution having a polymer concentration of 10 wt% and a viscosity of 3000 poise. To this solution, an agglomerated silica having an average particle size of 6 μm was added as an NMP slurry to the above polyamide solution so that the addition amount was 6 wt% per polymer.

After the polymer solution was filtered through a filter having a filtration accuracy of 3 μm, the film was heated with hot air at 180 ° C. for 2 minutes to evaporate the solvent, and the self-supporting film was continuously peeled off from the metal belt. Next, the film was introduced into a water tank having an NMP concentration gradient, and the residual solvent and the inorganic salts generated by neutralization were subjected to water extraction. At this time, the film was stretched 1.1 times in the longitudinal direction of the film. Subsequently, moisture was dried with a 280 ° C. stenter, stretched 1.4 times in the width direction and heat-treated, and then gradually cooled to finally obtain a 3.6 μm aromatic polyamide film.

The film was wound in the same manner as in Example 1 and subjected to corona discharge treatment.

Comparative Example 4 Spherical silica particles having an average particle diameter of 0.1 μm were dispersed in an ethylene glycol slurry state, and added during the polymerization of polyethylene terephthalate.
Polyethylene terephthalate chips with the added amount of
It was melt-extruded at 280 ° C., discharged from a T-die, and a sheet was obtained with a cooling drum.

The obtained polyester sheet was stretched 4.8 times at 120 ° C. in the longitudinal direction and 4.9 times at 110 ° C. in the width direction to obtain a film having a thickness of 4 μm.

The film was wound up in the same manner as in Example 1 and subjected to corona discharge treatment.

[0055]

[Table 1]

[0056]

Industrial Applicability The present invention provides a high-density magnetic recording medium having excellent adhesion between a magnetic layer and a base and excellent electromagnetic conversion characteristics as a magnetic tape, and an aromatic polyamide suitable for the medium and having excellent handling properties. A film and a film roll are provided.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G11B 5/73 G11B 5/73 // C08L 77:00 C08L 77:00 F term (Reference) 3F058 AA03 AB01 BB11 CA17 DA04 DB05 3J103 AA02 FA30 GA02 GA52 HA41 4F071 AA54 AB26 AF20 AF38 AH14 AH16 BA02 BB02 BB07 BC01 BC02 BC12 4F073 AA03 BA29 BA30 BB01 CA21 5D006 CB03 CB07

Claims (13)

[Claims] (1) at least one surface has a wetting tension of 4
The film has a center line surface roughness of at least 8 dyn / cm or more, a center line surface roughness of at least one surface of less than 3 nm, and a Young's modulus of 10 GPa or more.
Film roll characterized by the above range. 2. The film roll according to claim 1, wherein the film mainly comprises a polyamide resin. 3. The film roll according to claim 1, wherein one film is positive or negative and has a surface potential in a range of ± 10 KV. 4. A film having a thickness of 2 to 6 μm, a length of 2,000 m or more, a width of 500 mm or more, a film roll diameter of 300 mm or more, a lamination thickness of the film alone of 20 mm or more, and a winding hardness of 95 ° or more. The film roll according to any one of claims 1 to 3, wherein the film roll is in a range. 5. The surface potential of the film roll on the unwinding side in the range of ± 50 KV during or after unwinding at a speed of 100 m / min or more. The film roll according to 1. 6. The film roll according to claim 1, which is used for a high-density magnetic recording medium. 7. The method according to claim 1, wherein at least one side of the film has E
The film subjected to the discharge treatment having a value in the range of ³ to 30 W / m ² / min is wound up using a resin core having at least one or more conductive portions and at least one insulating portion. Characteristic method of manufacturing film roll. 8. The method according to claim 7, wherein when winding the film, the film is charged positively or negatively before winding. 9. The method for manufacturing a film roll according to claim 7, wherein a conductive portion of the resin core used for winding or unwinding is grounded directly or via an electric resistor. . 10. The method for producing a film roll according to claim 7, wherein the material of the touch roll used for winding is a material having conductivity. 11. A resin core comprising at least one conductive portion and at least one insulating portion. 12. The conductive part has a volume resistance of 10 ^9.
The resin core according to claim 11, wherein the resin core is less than Ωcm. 13. The resin core according to claim 11, wherein the conductive layer is present on the outer surface or the inner surface, and has a surface resistance of less than 10 ⁷ Ω / □.