JP2016016882A - Polyimide film roll package and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyimide film roll package in which electric discharge due to peeling charging does not occur when drawing a polyimide film roll after unpacking.SOLUTION: There is provided a polyimide film roll package in which a polyimide film roll is sealed with a package material. The polyimide film roll has a charging amount on a roll front layer during film taking-up within ±1 kV, and has an air biting ratio equal to or more than 0.8%. Relative humidity in the package is 40-70%.SELECTED DRAWING: Figure 1

Description

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

  Since polyimide films have high heat resistance and high electrical insulation, they are used in a wide range of industrial fields such as electrical insulation materials that require heat resistance. As one example, FPC base film and coverlay film have required characteristics such as mechanical characteristics, electrical characteristics, chemical resistance, heat resistance, and environmental resistance from the viewpoint of manufacturing and use. A polyimide film is widely used as a material that can withstand these problems. The FPC has a basic structure in which a circuit pattern is formed on a flexible and thin base film and a coverlay is applied to the surface.

  One method for making an FPC using a polyimide film as a base film is to laminate a metal foil such as copper on the film via an adhesive. However, when the surface of the polyimide film is charged, depending on the type of adhesive, the adhesive may be repelled, or conversely agglomerate, so the copper foil cannot be uniformly bonded. It can be seen. For this reason, a device that transports or winds a film is generally equipped with a static eliminator for static elimination or humidification to prevent electrification. Has proven to be difficult to later remove with a static eliminator. In particular, in peeling charging, which is a charge that is generated when a film is pulled out of a roll, it is known that ions generated by a static eliminator do not have an effective effect on static elimination because it is generated at the contact point where the film is separated. Therefore, it is common to remove the charge in a later process after peeling, but when the charge deteriorates until the discharge at the time of peeling, it becomes difficult to remove the charge as described above after that. End up.

  On the other hand, due to recent advances in mounting technology, the demand for high-density mounting has increased rapidly. In order to maintain the productivity and quality of FPC, film rolls can be wound around a polyimide film as a substrate. There is an increasing demand for appearance (longitudinal, widthwise wrinkles, and wrinkles over time). However, it is common that time is required from the production of the polyimide film roll to the actual processing. In particular, the polyimide film is highly hygroscopic, so it is known that the winding shape is likely to deteriorate due to moisture absorption after winding. In JP-A-8-230124, by defining the water absorption rate and winding hardness of the film, It is described that the deterioration of the winding shape of the polyimide film over time is prevented (see Patent Document 1). However, this method has not been able to improve the discharge due to the tightening due to the discharge of the entrained air generated after winding, or the discharge at the time of peeling due to the charging due to the deformation of the film due to moisture absorption or moisture removal. Furthermore, Japanese Patent Application Laid-Open No. 2000-177890 describes that a roll with a good winding shape can be created by using a contact roll with a specific groove when winding a film roll (Patent Document). 2). However, there is a problem that the use of a grooved contact roll increases the possibility of discharge due to peeling electrification when unwinding and processing after long-term storage.

Japanese Patent Laid-Open No. 8-23012 JP 2000-177890 A

  The present invention improves the above-described problems in the prior art, that is, charging due to tightening due to discharge of entrained air generated after winding, and discharge at the time of peeling due to charging due to film deformation due to moisture absorption or moisture removal, This was achieved as a result of examining the problem of discharge due to peeling charging when unwinding and processing after storage for a period of time.

  Accordingly, an object of the present invention is to provide a polyimide film roll package that does not generate discharge due to peeling charging when the unpacked polyimide film roll is pulled out, and a method for manufacturing the same.

  The present invention is a polyimide film roll package in which a polyimide film roll is sealed with a packaging material. The polyimide film roll has a roll surface charge amount within ± 1 kV at the time of film winding and an air biting rate. It is a polyimide film roll which is 0.8% or more, and is a polyimide film roll package whose relative humidity in the package is 40 to 70%.

  Furthermore, the present invention uses a touch roll having a groove-shaped surface, the charge amount of the roll surface layer when winding the film is within ± 1 kV, and the air biting rate is 0.8% or more and is a polyimide film Production of a polyimide film roll packaging body in which the wound polyimide film roll is sealed with a packaging material to produce a polyimide film roll packaging body having a relative humidity of 40 to 70% in the packaging body. Is the method.

  The present invention also provides a method for sealing a polyimide film roll having a roll surface layer charge amount of ± 1 kV or less and an air biting rate of 0.8% or more at the time of winding the film with a packaging material. It is the preservation | save method of the polyimide film roll which maintains the relative humidity of 40-70%.

  ADVANTAGE OF THE INVENTION According to this invention, when the polyimide film roll after unpacking is pulled out, the polyimide film roll package which does not generate | occur | produce the discharge by electrical charging and its manufacturing method can be provided.

  According to the method for packaging a polyimide film roll of the present invention, the surface of the polyimide film can be prevented from being peeled when unpacked, and the application of the adhesive during film processing can be prevented. Therefore, it is extremely useful for fields such as a base film for flexible printed circuit boards and a base film for high-density mounting.

FIG. 1 is a schematic view showing an example of a polyimide film roll package of the present invention. FIG. 2 is an explanatory diagram of a positively chargeable toner (red) and a negatively chargeable toner (blue) having different colors used for confirming the discharge trace. FIG. 3 is a schematic view of a polyimide film in which no peeling charge trace is seen. FIG. 4 is a schematic view of a polyimide film in which the peeled charge traces can be confirmed within 8 cm from either end in the width direction of the film, and the number thereof is 2 or less. FIG. 5 is a schematic diagram of a polyimide film in which the peeled charging traces can be confirmed, although the distance from both ends in the width direction of the film includes a distance longer than 8 cm, but the total number is two or less. FIG. 6 is a schematic view of a polyimide film in which the peeled charging traces can be confirmed within 8 cm from either end in the width direction of the film, and the number thereof is 3-5. In FIG. 7, the position at which the peeling charge trace can be confirmed, even if one of the occurrences occurs, the position that can be confirmed includes a distance that is longer than 8 cm from both ends in the width direction of the film. It is a schematic diagram of a polyimide film whose total number is more than three. FIG. 8 is a schematic view of a polyimide film in which the peeled charging traces can be confirmed within 8 cm from either end in the width direction of the film, and the number is more than six. FIG. 9 shows measured values of temperature and relative humidity in the polyimide film package of Example 7.

  The polyimide film roll in the present invention is a roll obtained by winding a polyimide film to a necessary length on a core or the like. The polyimide film roll is preferably a roll wound up by 500 m or more in the longitudinal direction. This is because when the winding length is short, the influence of air entrainment is reduced. The type of the core is not particularly limited, but plastic and FRP are preferable because they absorb less moisture and exhaust moisture depending on the environment.

  In the present invention, the charge amount of the roll surface layer when winding the film must be within ± 1 kV. If there is a charge higher than 1 kV at the time of winding, it not only discharges at the time of peeling, but also discharges at the time of winding. In order to wind the polyimide film without surface charging, install a static eliminator just before winding to cancel the charging with a sufficient amount of ions, or to make the material of the touch roll used conductive. It is possible to carry out with a facility response such as making the rubber a uniform contact. The charge amount of the roll surface layer at the time of winding the film is preferably ± 0.7 kV.

  In the present invention, the air biting rate of the film roll needs to be 0.8% or more. In the film winding roll, air is discharged from the end of the film after winding and tightened. At that time, the films are rubbed by the Poisson relaxation while the films are in contact with each other, so that the film is charged in the inner layer of the roll. In other words, the smaller the amount of air entrained, the less charge is stored in the interior, and no discharge occurs, so other management becomes unnecessary. The air biting rate of the film roll is preferably 1.2% or more.

  In order to set the charge amount of the roll surface layer at the time of film winding to within ± 1 kV and the air biting rate to 0.8% or more, for example, the film is discharged during film winding using a static eliminator, A touch roll having a shaped surface is used for winding.

  In the present invention, the relative humidity in the polyimide film package needs to be maintained at 40 to 70%. In the present invention, the relative humidity is a value indicating how much water is contained compared to the maximum amount of water that can be contained in air at a certain temperature. When the relative humidity is less than 40%, not only is charging easily caused by air discharge, but also a discharge phenomenon is likely to occur. On the other hand, when the relative humidity exceeds 70%, a phenomenon of blocking where the films stick to each other easily occurs, and the film may not be stably pulled out from the roll.

  In this invention, it is preferable that the surface of the touch roll used when winding a polyimide film in roll shape has a groove shape.

  In the present invention, the relative humidity in the polyimide film package is preferably 50 to 70%.

  In the present invention, the means for maintaining the relative humidity in the polyimide film package at 40 to 70% is, for example, sealed with a sheet material having a low moisture permeability and containing a humidity control agent.

Specifically, the sheet agent used as the exterior is hermetically sealed with a moisture permeability of 20 g / m ² · 24 h or less, and the moisture content is adjusted to a moisture content of 50 to 60% inside the sealed body inside the sheet material. It is manufactured by packaging.

  Moreover, it is preferable that the humidity control agent used in this invention is 50 to 60% of humidity control. Examples of the humidity control agent include Nikka Pellet OK-1 manufactured by Toshin Kasei Co., Ltd., Artsorb manufactured by Fuji Silysia Co., Ltd., and the like.

  In the present invention, the total change in relative humidity is preferably within 50%, and more preferably within 40%. The total change in relative humidity is the absolute value when the relative humidity on the second day is calculated as the difference between the relative humidity on the first day of packaging and the relative humidity on the second day of packaging. The integrated value is taken as the amount of humidity change. The polyimide film is easy to absorb and exhaust moisture, and the film expands or contracts due to moisture absorption and exhaustion. Therefore, every time the relative humidity changes, the film is deformed, and the films are rubbed to charge the inner layer of the roll. In the present invention, more preferably, the total change in relative humidity when stored for 40 days is within 50%, and even more preferably, the total change in relative humidity when stored for 60 days is within 50%. is there.

  The packaging material in the present invention is preferably a polyethylene sheet or a polypropylene sheet, and more preferably a metal laminate sheet having an aluminum film as a moisture-proof layer.

The packaging material is preferably a sheet material having a moisture permeability of 20 g / m ² · 24 h or less, and more preferably 2 g / m ² · 24 h or less. If the moisture permeability is high, there is a tendency that the relative humidity cannot be maintained due to the atmosphere outside the package.

  In the present invention, it is preferable that the polyimide film roll before packaging is stored in a room with a relative humidity of 50-60% for 48 hours or more immediately after winding, and then packaged in a room with a relative humidity of 50-60%. Moisture absorption and drainage of the film roll proceeds from the surface layer or end surface of the film to the inner layer, and therefore it takes time until the atmosphere where the roll is placed is saturated. However, 48 hours is sufficient. The polyimide film thus packaged is less likely to be charged because the film roll itself functions as a humidity control agent and contributes to maintaining the relative humidity of the package.

  The polyimide film in the present invention is produced by imidizing a film using polyamic acid dissolved in an organic solvent, and the polyamic acid in the organic solvent solution may be partially imidized. A small amount of an inorganic compound may be contained.

  The polyamic acid which is a polyimide precursor in the present invention is preferably composed of an aromatic tetracarboxylic acid and an aromatic diamine and composed of a repeating unit represented by the following formula [I].

  In the above formula, R1 is a tetravalent organic group having at least one aromatic ring, the carbon number is 25 or less, and R2 is a divalent organic group having at least one aromatic ring. The carbon number is 25 or less.

  In the present invention, the aromatic tetracarboxylic acids and the aromatic diamines are polymerized in such a ratio that the respective mole numbers are approximately equal, and one of them is within a range of 10 mol%, preferably 5 mol%, and the other. May be blended in excess.

  Specific examples of the aromatic tetracarboxylic acids include pyromellitic acid, 3,3 ′, 4,4′-biphenyltetracarboxylic acid, 2,3 ′, 3,4′-biphenyltetracarboxylic acid, 3,3 ', 4,4'-benzophenonetetracarboxylic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) propane, pyridine-2,3,5,6 -Aromatic tetracarboxylic acids derived from tetracarboxylic acids or acid anhydrides, or ester compounds or halides of the acids.

  Specific examples of the aromatic diamines include paraphenylene diamine, metaphenylene diamine, benzidine, paraxylylene diamine, 4,4′-diaminodiniphenyl ether, 3,4′-diaminodiphenyl ether, 4,4′- Diaminodiphenylmethane, 4,4′-diaminodiphenylsulfone, 3,3′-dimethyl-4,4′-diaminodiphenylmethane, 1,5-diaminonaphthalene, 3,3′-dimethoxybenzidine, 1,4-bis (3-methyl -5-aminophenyl) benzene and derivatives thereof.

  Examples of combinations of an aromatic tetracarboxylic acid component and an aromatic diamine component that are particularly suitable for the polyimide in the method of the present invention include pyromellitic dianhydride, 4,4′-diaminodiphenyl ether, and 3,3 ′, 4,4 ′. -A combination of biphenyltetracarboxylic dianhydride and 4,4'-diaminodiphenyl ether is mentioned, and further, copolymerization thereof and / or copolymerization of paraphenylenediamine is preferable. Moreover, if it is a range which does not inhibit this invention, it can also shape | mold with a multilayer body at the time of film forming.

  The intrinsic viscosity (measured in sulfuric acid at 25 ° C.) of the polyimide is preferably in the range of 0.2 to 3.0, more preferably in the range of 0.8 to 2.

  In the present invention, specific examples of the organic solvent used for forming the polyamic acid solution include organic polar amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methyl-2-pyrrolidone. A solvent is mentioned, These organic solvents are used individually or in combination of 2 or more types, but may be used in combination with non-solvents such as benzene, toluene and xylene.

  The organic solvent solution of polyamic acid used in the present invention preferably contains a solid content of 5 to 40% by weight, more preferably 10 to 30% by weight, and its viscosity is 10 as measured by a Brookfield viscometer. Those having a viscosity of ˜2000 Pa · s, preferably 100 to 1000 Pa · s are preferable because stable liquid feeding is possible.

  The polymerization reaction is continuously carried out in the temperature range of 0 to 80 ° C. for 10 minutes to 30 hours while stirring and / or mixing in an organic solvent. The polymerization reaction can be divided or the temperature can be increased or decreased as necessary. It does not matter.

  In this case, the order of addition of both reactants is not particularly limited, but it is preferable to add aromatic tetracarboxylic acids to the solution of aromatic diamines.

  Vacuum degassing during the polymerization reaction is an effective method for producing a good quality organic solvent solution of polyamic acid. Moreover, you may perform polymerization by adding a small amount of terminal blockers to aromatic diamines before a polymerization reaction.

  Specific examples of the ring-closing catalyst used in the present invention include aliphatic tertiary amines such as trimethylamine and triethylamine, and heterocyclic tertiary amines such as isoquinoline, pyridine and betapicoline. It is preferable to use at least one amine selected from tertiary amines.

  Specific examples of the dehydrating agent used in the present invention include aliphatic carboxylic acid anhydrides such as acetic anhydride, propionic anhydride, and butyric anhydride, and aromatic carboxylic acid anhydrides such as benzoic anhydride, Acetic anhydride and / or benzoic anhydride are preferred.

  The content of the ring-closing catalyst with respect to the polyamic acid is preferably in a range where the content (mol) of the ring-closing catalyst / the content (mol) of the polyamic acid is 0.5 to 8.

  Further, the content of the dehydrating agent relative to the polyamic acid is preferably in a range where the content of dehydrating agent (mol) / the content of polyamic acid (mol) is 0.1 to 4. In this case, a gelation retarder such as acetylacetone may be used in combination.

  The polyimide film of the present invention is manufactured by peeling a gel film, which is continuously extruded or coated in a film form on a rotating support of a polyamic acid solution, from the support, stretching, drying, and heat treatment. However, as a typical method for producing a polyimide film from an organic solvent of polyamic acid, a film is prepared by casting an organic solvent solution of polyimide acid containing no ring-closing catalyst and a dehydrating agent from a slit base onto a support. A heat-cycling method in which the film is formed into a gel film having a self-supporting property by heating and drying on a support, then the film is peeled off from the support, and further imidized by drying and heat treatment at a high temperature, and ring closure A film obtained by casting an organic solvent of polyamic acid containing a catalyst and a dehydrating agent onto a support from a die with a slit Molded, allowed to proceed partially imidized on the support after the film having self-supporting properties, the film was detached from the support, and heated drying / imidization, chemical cyclization method may be used to perform the heat treatment.

  The present invention may employ any of the above ring closure methods, but the chemical ring closure method requires a facility for containing a ring closure catalyst and a dehydrating agent in an organic solvent solution of polyamic acid, but has a self-retaining gel. It can be said that it is a more preferable method in that a film can be obtained in a short time.

  The gel film referred to in the present invention is a polyimide film containing a polyimide precursor and / or a partially imidized solvent.

  Next, characteristics evaluation methods and evaluation criteria used in the description of the present invention will be described.

(1) Confirmation of discharge traces For films visualized by the dust figure method, if there is even one with positive and negative charges V-shaped and aligned within 5 cm in the longitudinal direction by visual confirmation, there is a peeling discharge trace Judged as.

  In order to visualize positive and negative charges, positively charged toners (red) and negatively charged toners (blue) having different colors were used. The used toner has the following specifications, and was visualized by the dust figure method in an environment of 50% humidity.

Positively charged toner:
Color: Red Particle size: Weight average particle size: 14.8 μm (6 μm or less: 0.2 wt%, 25 μm or more: 1.8 wt%)
Specific charge: -1.2 μC / g
Negatively chargeable toner:
Color: Blue Particle size: Weight average particle size: 12.5 μm (6 μm or less: 0.8 wt%, 20 μm or more: 1.6 wt%)
Specific charge: −23.1 μC / g
The average particle diameter of the toner is a value measured with a MULTISIZER (II) manufactured by COULTER, using an aperture tube having a diameter of 100 μm. The specific charge is a value measured by a blow-off method electrification measuring device (TB-500 type manufactured by Toshiba Chemical). Specifically, a toner sample to be measured and an iron powder carrier (TSV-200R manufactured by Powder Tech Co., Ltd.) are mixed at a weight ratio of 1:19, and a powder sample after stirring for 5 minutes from a ball mill is used to measure the charge amount. Only 0.2 g was put in the measurement cell of the apparatus, the blow pressure was 0.5 kg / cm ² , the blow time was 60 seconds, and the value measured using a 400 mesh stainless mesh for the stitch screen was the toner weight (0.2 g × 1 /20=0.01 g).

  When the film is pulled out at a speed of 10 m / min for 2 minutes, the last 3 m in the longitudinal direction and the width direction is searched for peeling discharge traces for the entire width of the roll. Evaluation was made according to the following criteria depending on the number that was made, and a value of ○ or more was regarded as an acceptable range.

◎: No peeling electrification mark is seen
A to B: peeling charge traces are observed, but the confirmed positions are within 8 cm from either end in the width direction of the film, and the number is within 2.

  ○: Although peeling electrification traces are seen, the confirmed positions include distances from both ends in the width direction of the film that are longer than 8 cm, but the total number is within 2 or the width direction of the film It is within 8 cm from either end, and the number is 3-5.

  X: The position that could be confirmed even if either one occurred was a distance that is longer than 8 cm from both ends in the width direction of the film, and the total number is more than 3, or the width direction of the film Although it is within 8 cm from either end, the number is more than six.

(2) Charge amount of polyimide film roll surface layer At a distance of 50 mm from the surface of the rolled film roll, the charge amount of 5 points obtained by equally dividing the roll in the width direction was measured with a stantilon DZ (manufactured by Sicid Electric). The average value was used.

(3) Relative humidity measurement Relative humidity was continuously measured every 5 minutes during the storage period using a temperature / humidity data logger EL-USB-2 manufactured by LASCER.

(4) Humidity change The average daily relative humidity is obtained, the amount of change per day is calculated by the following formula (1), and the absolute value integrated is defined as the humidity change (formula (1)). .
Relative humidity on the first day of packaging-Relative humidity on the second day of packaging = Amount of change on the second day (1)
Humidity change amount || Change amount on the second day | + | Change amount on the third day | + | + | Change amount on the unpacking date | ・ (2).

(5) Air biting rate The outer diameter of the core before winding is measured with pie tape, and the outer diameter of the film wound using the core is measured with pie tape. Using that value,

Calculated.

(6) Moisture permeability (water vapor permeability)
Measured according to JIS Z 02080: 1976 moisture permeation test method ((cup method) of moisture-proof packaging material.

  Hereinafter, the present invention will be described by way of examples.

[Example 1]
“Kapton” (registered trademark of DuPont) 100EN (polyimide film [thickness 25.0 μm]; manufactured by Toray DuPont Co., Ltd.) is wound using a film winder at a wind speed of 100 m / min. A polyimide film roll having a width of 524 mm and a length of 1500 m was wound using a static eliminator during winding at a surface pressure of 270 N / m and a winding tension of 80 N / m. The contact roll used was a lateral groove contact roll, the charge amount of the roll was -0.6 kV, and the air biting rate was 1.0%.

  20 g of B-type silica gel (manufactured by Toyoda Chemical Co., Ltd.) was conditioned in an environment of a temperature of 22 ° C. and a relative humidity of 55% until there was no change in weight, and packed in a bag made of nonwoven fabric.

After winding, the temperature / humidity data logger EL-USB-2 (manufactured by LASSER), the polyimide film roll, and the non-woven fabric are taken with a polyethylene sheet (moisture permeability of 15.2 g / m ² · 24 h, thickness of 0.055 mm) without taking time. The B-type silica gel packed in was sealed in a room with a relative humidity of 55%. This roll was stored for 60 days in a warehouse where direct sunlight did not enter, and the humidity and the amount of change in humidity were measured. When the discharge trace was confirmed after storage for 60 days, two discharge traces were confirmed, one of which was at a position 12 cm from the end in the width direction of the film. The relative humidity change range, humidity change amount, and discharge mark evaluation results are shown in Table 1.

[Example 2]
“Kapton” (registered trademark of DuPont) 100H (polyimide film [thickness 25.0 μm]; manufactured by Toray DuPont Co., Ltd.) was treated in the same manner as in Example 1 to obtain a polyimide having a width of 524 mm and a length of 1500 m. The film roll was wound up. The charge amount of the roll was -0.6 kV, and the air biting rate was 1.0%.

  The roll was sealed and stored for 60 days in the same manner as in Example 1. When the discharge traces were confirmed after storage for 60 days, four discharge traces were confirmed, all of which were within 8 cm from the end in the width direction of the film. The relative humidity change range, humidity change amount, and discharge mark evaluation results are shown in Table 1.

[Example 3]
“Kapton” (registered trademark of DuPont) 150EN (polyimide film [thickness: 37.5 μm]; manufactured by Toray DuPont Co., Ltd.) is wound using a film winder at a winding speed of 60 m / min. A polyimide film roll having a width of 524 mm and a length of 500 m was wound using a static eliminator at the time of winding at a surface pressure of 200 N / m and a winding tension of 80 N / m. The contact roll used was a lateral groove contact roll, the charge amount of the roll was 0.1 kV, and the air biting rate was 0.8%.

  The roll was subjected to sealing treatment and storage for 60 days in the same manner as in Example 1, and the humidity and the amount of change in humidity were measured. When the discharge traces were confirmed after storage for 60 days, three discharge traces were confirmed, all of which were within 8 cm from the end in the width direction of the film. The relative humidity change range, humidity change amount, and discharge mark evaluation results are shown in Table 1.

[Comparative Example 1]
A polyimide roll that was stored for 60 days and measured for humidity and humidity change, except that it was not sealed with a polyethylene sheet and was not bundled with B-type silica gel. Got. When the discharge trace was confirmed with respect to the roll, 30 discharge traces were confirmed, and 10 of them were positions outside 8 cm or less from the end in the width direction of the film. The relative humidity change range, humidity change amount, and discharge mark evaluation results are shown in Table 1.

[Comparative Example 2]
A polyimide roll that was stored for 60 days and measured for humidity and humidity change, except that it was not sealed with a polyethylene sheet and was not bundled with B-type silica gel. Got. When the discharge trace was confirmed with respect to the roll, 40 discharge traces could be confirmed, and eight of them were positions outside 8 cm or less from the end in the width direction of the film. The relative humidity change range, humidity change amount, and discharge mark evaluation results are shown in Table 1.

[Example 4]
“Kapton” (registered trademark of DuPont) 100EN (polyimide film [thickness: 25.0 μm]; manufactured by Toray DuPont Co., Ltd.) is wound using a film winding device at a winding speed of 60 m / min. A polyimide film roll having a width of 524 mm and a length of 1500 m was wound using a static eliminator at the time of winding at a surface pressure of 175 N / m and a winding tension of 80 N / m. The contact roll used was a flat contact roll, the charge amount of the roll was -0.3 kV, and the air biting rate was 0.8%.

  The roll was subjected to sealing treatment and storage for 60 days in the same manner as in Example 1, and the humidity and the amount of change in humidity were measured. When the discharge trace was confirmed after storage for 60 days, one discharge trace was confirmed, but the position was within 8 cm from the end in the width direction of the film. The relative humidity change range, humidity change amount, and discharge mark evaluation results are shown in Table 1.

[Comparative Example 3]
A polyimide roll that was stored for 60 days and measured for humidity and humidity change, except that it was not sealed with a polyethylene sheet and was not bundled with B-type silica gel. Got. When the discharge trace was confirmed with respect to the roll, 20 discharge traces could be confirmed, and five of them were positions outside 8 cm or less from the end in the width direction of the film. Table 2 shows the relative humidity change range, humidity change amount, and discharge mark evaluation results.

[Comparative Example 4]
“Kapton” (registered trademark of DuPont) 100EN (polyimide film [thickness: 25.0 μm]; manufactured by Toray DuPont Co., Ltd.) is wound using a film winding device at a winding speed of 60 m / min. A polyimide film roll having a width of 524 mm and a length of 1500 m was wound up using a static eliminator during winding at a surface pressure of 220 N / m and a winding tension of 80 N / m. The contact roll used was a flat contact roll, the charge amount of the roll was -0.9 kV, and the air biting rate was 0.6%.

  The roll is stored for 60 days by performing the same operation as in Example 1 except that the polyethylene sheet is not sealed and the B-type silica gel is not bundled. A polyimide roll whose amount was measured was obtained. When the discharge trace was confirmed with respect to this roll, two discharge traces were confirmed, and one of them was a position 15 cm from the end in the width direction of the film. Table 2 shows the relative humidity change range, humidity change amount, and discharge mark evaluation results.

[Example 5]
After winding, the roll was taken to a room conditioned at a room temperature of 22 ° C. and a relative humidity of 55% without taking any time, and stored for 60 days by performing the same operation as in Example 1 except that it was left for 50 hours. Thus, a polyimide roll whose humidity and humidity change amount were measured was obtained. When the discharge trace was confirmed with respect to this roll, one discharge trace was confirmed, but the position was within 8 cm from the end in the width direction of the film. Table 2 shows the relative humidity change range, humidity change amount, and discharge mark evaluation results.

[Example 6]
Store for 60 days by performing the same operation as in Example 1 except that polyethylene was changed to a polyethylene bag with aluminum vapor deposition (moisture permeability of 0.9 g / m ² · 24 h, thickness of 0.102 mm). The polyimide roll which measured humidity and the amount of humidity changes was obtained. When the discharge trace was confirmed with respect to this roll, one discharge trace was confirmed, but the position was within 8 cm from the end in the width direction of the film. Table 2 shows the relative humidity change range, humidity change amount, and discharge mark evaluation results.

[Example 7]
Store for 60 days by performing the same operation as in Example 5 except that the polyethylene was changed to a polyethylene bag with aluminum vapor deposition (moisture permeability of 0.9 g / m ² · 24 h, thickness of 0.102 mm). The polyimide roll which measured humidity and the amount of humidity changes was obtained. When the discharge trace was confirmed with respect to this roll, the discharge trace could not be confirmed at all. Table 2 shows the relative humidity change range, humidity change amount, and discharge mark evaluation results. FIG. 9 shows measured values of temperature and relative humidity in the polyimide film package when stored for 60 days.

[Comparative Example 5]
“Kapton” (registered trademark of DuPont) 100EN (polyimide film [thickness 25.0 μm]; manufactured by Toray DuPont Co., Ltd.) using a winding device, winding speed of 100 m / min, winding surface The film was wound at a pressure of 270 N / m and a winding tension of 80 N / m, and a polyimide film roll having a width of 524 mm and a length of 1500 m was wound. The contact roll used was a lateral groove contact roll, the charge amount of the roll was -3.2 kV, and the air biting rate was 1.0%. When the discharge trace of this roll was confirmed, 22 discharge traces were confirmed, and eight of them were positions outside 8 cm or less from the end in the width direction of the film. Table 2 shows the relative humidity change range, humidity change amount, and discharge mark evaluation results.

  In Tables 1 and 2, the term “humidifier 55%” means that the humidity controller is conditioned until there is no change in weight in an environment of a temperature of 22 ° C. and a relative humidity of 55%.

Claims (9)

A polyimide film roll package in which a polyimide film roll is sealed with a packaging material, and the polyimide film roll has a roll surface charge amount within ± 1 kV at the time of film winding and an air biting rate of 0.8%. The polyimide film roll package which is the polyimide film roll which is the above and whose relative humidity in a package is 40 to 70%. The polyimide film roll package according to claim 1, wherein the total change in relative humidity in the package is within 50%. The packaging material is a sheet material having a moisture permeability of 20 g / m ² · 24 h or less, and a moisture conditioner having a moisture content of 50 to 60% is enclosed in a sealed body inside the sheet material. The polyimide film roll package of description. The polyimide film roll package according to claim 3, wherein the sheet material is a metal laminate sheet having an aluminum film as a moisture-proof layer. Using a touch roll having a groove-shaped surface, the surface charge of the roll when winding the film is within ± 1 kV, and the polyimide film is wound into a roll with an air biting rate of 0.8% or more. The polyimide film roll package is produced by sealing the wound polyimide film roll with a packaging material to produce a polyimide film roll package having a relative humidity of 40 to 70% in the package. A polyimide film roll packaging method in which a polyimide film roll is sealed with a packaging material and a humidity control agent having a moisture content of 50 to 60% is enclosed inside the packaging material, and the packaging material has a moisture permeability of 20 g. The method for producing a polyimide film roll package according to claim 5, wherein the sheet material is / m ² · 24h or less. The polyimide according to claim 5 or 6, wherein the polyimide film roll before packing is stored in a room with a relative humidity of 50 to 60% for 48 hours or more immediately after winding, and then packaged in a room with a relative humidity of 50 to 60%. Manufacturing method of film roll package. A polyimide film roll having a charge amount of the roll surface layer of ± 1 kV or less when the film is wound and an air biting rate of 0.8% or more is sealed with a packaging material, and the relative humidity in the package is 40 to 40%. Storage method of polyimide film roll maintained at 70%. The preservation | save method of the polyimide film roll of Claim 8 whose sum total of the change of the relative humidity in a package is 50% or less.