JP2005187781A - Polyimide film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a film having a small electrostatic charge without causing the reduction of adhesiveness. <P>SOLUTION: The film is a rolled polyimide film obtained by winding a polyimide film on a winding core, wherein the rolled polyimide film is characterized in that the amount of the electrostatic charge of the unwinding part and the outer surface of the roll when measured while unwinding the rolled polyimide film are not higher than 15 kV. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a roll-shaped polyimide film obtained by being wound around a core, and more specifically, a polyimide film having a small amount of static electricity, no dust and dust uptake, and good workability such as running characteristics, The present invention relates to a roll-shaped polyimide film having excellent adhesiveness.

  A polymer film such as an aromatic polyimide film has a high tendency to generate static electricity and easily attracts dust and dirt to the film surface. Generally, when a polyimide film is continuously produced, a long film of, for example, 1500 m is shipped in the form of a winding roll on a core. The film wound up in a roll shape is particularly prone to accumulate static electricity, causing an electric shock due to the accumulation of static electricity, reducing the slip characteristics of the film, adversely affecting running characteristics, and handling the film. There was also a problem.

  In general, a polymer film such as an aromatic polyimide film is subjected to electrical treatment such as corona treatment and plasma treatment for the purpose of imparting adhesiveness, so that static electricity tends to increase. Static electricity generated by electrical treatment is often accompanied by the occurrence of a charged pattern (static mark) on the polyimide film, and it is difficult to eliminate static electricity. In addition, once static elimination treatment is performed, the amount of static electricity increases over time, static electricity is generated due to peeling when a roll-shaped film is fed out, and generation of static electricity due to contact and peeling with a transport roll is increased. To do.

  In order to solve these problems, various proposals have been made, such as improving the static elimination method and imparting antistatic properties to the polymer film.

  In the improvement of the static elimination method, the addition of static elimination devices, the static elimination method and apparatus for detecting static electricity on the film surface and controlling the static elimination output, Patent Document 1 discloses a static elimination method in which positive and negative ion generation electrodes and ion attraction electrodes are arranged to face each other. And devices have been developed. In Patent Document 2, a method has been developed in which charging is performed so that the charging polarity on one side is uniform with respect to one side of the insulating sheet, and then neutralization is performed from the same side to remove the charge on the processing surface. Yes. However, even if these methods are used, a charged pattern (static mark) generated by electrical processing cannot be removed. For this reason, in the polyimide film used in the form of a roll, in use, generation of static electricity due to peeling at the time of feeding, contact with a transport roll, generation of static electricity due to peeling is large, and various defects are generated.

  On the other hand, in a method for imparting antistatic properties to a polymer film, for example, a film is obtained by adding or applying a conductive material such as carbon black to the film, or by incorporating or applying an antistatic agent on the film. To be given antistatic properties. However, these methods have significant problems. First, in the first case, a large amount of conductive material (eg carbon black) must generally be added to the film in order to obtain the required degree of antistatic properties. The resulting film is an unfavorable black color and has a reduced mechanical strength, so a commercial value must be compromised. In addition, coatings filled with carbon black can produce sludge, and thus, contamination around the filler is caused by black conductive strips in nature.

  In the latter case, conventional antistatic agents are generally organic in nature and can be easily decomposed by raising the temperature above the 400 ° C. required to convert the polyamic acid precursor to polyimide, thus providing the desired static electricity. It is difficult to impart protective properties to the film.

With respect to these problems, Patent Document 3 contains conductive silica particles coated with a layer of tin oxide containing antimony, and has good heat resistance even after heat treatment at a temperature of 400 ° C. or higher. We are developing polyimide films that exhibit excellent antistatic properties while maintaining their mechanical properties. However, in order to exhibit sufficient antistatic properties, it is necessary to contain a large number of conductive silica particles, which has a drawback that it does not exhibit mechanical properties suitable for flexible printed circuit board applications, particularly tensile elongation.
Japanese Patent No. 2651476 JP 2002-289394 A JP-A-10-77406

  In view of the above situation, as a result of intensive studies, the present inventors have found that the above problems do not occur with respect to the polyimide film used for the base film for flexible printed circuit boards, the base film for high-density mounting, etc. This led to the invention of a small polyimide film. It is another object of the present invention to provide a film with low static electricity without reducing adhesiveness.

  (Reclaim claims)

  According to the present invention, static electricity is small, foreign matter does not occur, process troubles due to electric shock or running abnormalities in processing a film do not occur, and characteristics and quality of the final product are deteriorated. Therefore, it is useful when used for a base film for flexible printed circuit boards, a base film for high-density mounting, and the like. In addition, a film with low static electricity can be provided without reducing adhesiveness.

  Hereinafter, the form of the polyimide film concerning this invention is demonstrated concretely. First, the polyimide film concerning this invention and its manufacturing method are demonstrated.

  The polyimide film according to the present invention is obtained from various known raw materials and is not particularly limited. Mainly using organic tetracarboxylic dianhydride and organic diamine as raw materials, each component is substantially used. It is obtained via a polyamic acid varnish obtained by using equimolar amounts and polymerizing in an organic solvent solution.

  For the purpose of forming a stable polyimide film, this polyamic acid varnish has a remarkably high quality of conductive fillers such as calcium phosphate, calcium hydrogen phosphate, silica, mica, titanium oxide, alumina, and glass beads. You may add in the range which does not fall.

The polymerization reaction is not limited by a known method.
As an example of the polymerization method, one or two diamines are dispersed in an organic solvent in a solution or a slurry in an inert gas atmosphere such as argon or nitrogen. At least one tetracarboxylic dianhydride is added to this solution in a solid state, an organic solvent solution state or a slurry state to obtain a polyamic acid varnish. The reaction temperature at this time is −20 ° C. to 50 ° C., preferably 20 ° C. or less. The reaction time is preferably 1 to 6 hours.

  In this reaction, contrary to the order of addition, tetracarboxylic dianhydride is first dissolved or dispersed in an organic solvent, and a solution or slurry of the diamine solid or organic solvent is added to the solution. Also good. Moreover, you may make it react simultaneously, and the addition order of a tetracarboxylic dianhydride component and a diamine component is not limited.

  Polymerization of polyamic acid is generally carried out in two stages. In the first stage, a low-viscosity polyamic acid called a prepolymer is polymerized, and then a tetracarboxylic dianhydride or diamine compound is dissolved in an organic solvent. A highly viscous polyamic acid is obtained while adding a solvent. When shifting from the first stage to the second stage, a process for removing undissolved raw materials and mixed foreign substances in the prepolymer with a filter or the like is provided to reduce foreign substances and defects in the film. The aperture of the filter is preferably 1/2, preferably 1/5, and more preferably 1/10 of the thickness of the obtained film.

  The weight% of the polyamic acid in the organic solvent is preferably 5-40 wt%, preferably 10-30 wt%, more preferably 13-25 wt% of the polyamic acid in the organic solvent from the viewpoint of handling. The average molecular weight of the polyamic acid is preferably in the range of 10,000 to 1,000,000, more preferably in the range of 50,000 to 500,000, and most preferably in the range of 100,000 to 500,000 in terms of polyethylene glycol by GPC measurement. . If it is out of this range, the mechanical properties are not satisfied if the molecular weight is low. Further, when the molecular weight is high, the handleability is poor and the productivity is greatly reduced.

  Examples of the organic solvent used for the polymerization of the polyamic acid include ureas such as tetramethylurea, N, N-dimethylethylurea, sulfoxides or sulfones such as dimethylsulfoxide, diphenylsulfone, and tetramethylsulfone, N, N Aprotic solvents of amides such as methylacetamide, N, N-dimethylformamide, N, N′-diethyl N-methyl-2-pyrrolidone, γ-butyllactone, hexamethylphosphoric triamide, or phosphorylamides , Alkyl halides such as chloroform and methylene chloride, aromatic hydrocarbons such as benzene and toluene, phenols such as phenol and cresol, ethers such as dimethyl ether, diethyl ether and p-cresol methyl ether. , Normal but use of these solvents alone may be used in combination of two or more as needed.

  The solvent used in the present invention may be a commercially available special grade or first grade, as it is, but these solvents are used after carrying out a dehydration purification treatment by a normal operation such as dry distillation. May be.

  Further, after use in the present invention, the volatile solvent may be recovered and purified before use. At this time, a certain kind of mixed solvent may be obtained after purification. Specifically, a solvent decomposition product or the like may be mixed in the recovered solvent, but it can be appropriately used in view of film properties.

  Polyimide is obtained by imidizing polyamic acid, and either a thermal curing method or a chemical curing method is used for imidization. The thermal cure method is a method in which an imidization reaction proceeds by heating alone without the action of a dehydrating ring-closing agent or the like. In addition, the chemical curing method is carried out by adding a chemical conversion agent typified by an acid anhydride such as acetic anhydride, and a pyridine derivative such as quinoline, isoquinoline, β-picoline, 3,5-lutidine, etc. to a polyamic acid organic solvent solution. In this method, a catalyst typified by a tertiary amine is used. A thermal cure method may be used in combination with a chemical cure method. The reaction conditions for imidization can vary depending on the type of polyamic acid, the thickness of the film, the selection of a thermal curing method and / or a chemical curing method, and the like. Preferably, it is chemically cured from the viewpoints of film toughness, breaking strength, and productivity.

  Next, the material used for the polyimide precursor polyamic acid composition concerning this invention is demonstrated.

  Suitable tetracarboxylic anhydrides for use in this polyimide are pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3 ′, 4,4′-biphenyl. Tetracarboxylic dianhydride, 1,2,5,6-naphthalene tetracarboxylic dianhydride, 2,2 ′, 3,3′-biphenyltetracarboxylic dianhydride, 3,3 ′, 4,4 ′ -Benzophenonetetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis (3,4- Dicarboxyphenyl) propane dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2 , 3- Carboxyphenyl) methane dianhydride, bis (3,4-dicarboxyphenyl) ethane dianhydride, oxydiphthalic dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, p-phenylenebis (tri Including merit acid monoester acid anhydride), ethylene bis (trimellitic acid monoester acid anhydride), bisphenol A bis (trimellitic acid monoester acid anhydride) and the like, these alone or in any A mixture of proportions can be preferably used.

  Among these, the most suitable tetracarboxylic dianhydride in the polyimide precursor polyamic acid composition used in the present invention is pyromellitic dianhydride, from the viewpoint of the mechanical properties and moisture absorption properties of the resulting polyimide film. ', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, p-phenylenebis (trimellitic acid monoester acid anhydride), These may be used alone or in any desired mixture.

  In general, tetracarboxylic dianhydride contains tetracarboxylic acid and tetracarboxylic acid monoanhydride, which are ring-opened products due to moisture, as impurities, but the tetracarboxylic dianhydride used in the present invention is a machine for the polyimide film obtained. From the viewpoint of mechanical strength and adhesiveness, it is preferable that the purity is high, and the purity is preferably an impurity amount of 1.5 wt% or less, more preferably an impurity amount of 1 wt% or less, most preferably an impurity amount of 0 .5 wt% or less.

  Suitable diamines that can be used in the polyimide precursor polyamic acid composition according to the present invention are 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenylmethane, benzidine, 3,3′-dichlorobenzidine, 4,4. '-Diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1, 5-diaminonaphthalene, 4,4′-diaminodiphenyldiethylsilane, 4,4′-diaminodiphenylsilane, 4,4′-diaminodiphenylethylphosphine oxide, 4,4′-diaminodiphenyl N-methylamine, 4,4 '-Diaminodiphenyl N-phenylamine, 1,4-diaminobenzene (p-phenylenediamine), 1,3-diaminobenzene, 1,2-diaminobenzene, and the like, which are used alone or in a mixture in any proportion Can be preferably used.

  Among these diamines, 4,4′-diaminodiphenyl ether and / or p-phenylenediamine are particularly preferable, and these are in a molar ratio of 100: 0 to 0: 100, preferably 100: 0 to 10:90, more preferably. A mixture mixed at a ratio of 100: 0 to 40:60, more preferably 90:10 to 60:40 can be preferably used.

  Further, when the imidization is performed by a chemical curing method, the chemical conversion agent added to the polyamic acid composition according to the present invention is, for example, an aliphatic acid anhydride, an aromatic acid anhydride, N, N′-dialkylcarbodiimide, Examples include lower aliphatic halides, halogenated lower aliphatic halides, halogenated lower fatty acid anhydrides, arylphosphonic acid dihalides, thionyl halides, or mixtures of two or more thereof, among which organic carboxylic acid anhydrides are preferred. Here, as the organic carboxylic acid anhydride, acetic anhydride, propionic anhydride, butyric anhydride, valeric anhydride, anhydrides mixed with each other, and aromatic monocarboxylic acids such as benzoic acid and naphthoic acid Mixtures with anhydrides such as carbonic acid, formic acid and aliphatic ketenes (ketene, and dimethylketene) anhydrides, and aliphatic anhydrides such as acetic anhydride, propionic anhydride, and anhydride, or 2 of them A mixture of two or more species can be mentioned, and among them, acetic anhydride can be preferably used. The amount of the chemical conversion agent can be used in a molar ratio of 1.0 to 8.0 times, more preferably 1.2 to 5.0 times, per mole of the amic acid of the polyamic acid varnish. If the amount of the chemical conversion agent is too small, the imidization rate tends to be smaller than the preferred range. If the amount is too large, decomposition occurs in the process of forming a partially cured and / or partially dried polyamic acid film. It progresses and the target mechanical properties are not expressed.

  Moreover, in order to perform imidation effectively, it is preferable to use a catalyst simultaneously with a chemical conversion agent. As the catalyst, aliphatic tertiary amine, aromatic tertiary amine, heterocyclic tertiary amine and the like are used. Among them, those selected from heterocyclic tertiary amines can be particularly preferably used. Specifically, quinoline, isoquinoline, β-picoline, pyridine and the like are preferably used. The amount of the catalyst may be 0.2 to 2.0 times, more preferably 0.3 to 1.5 times in molar ratio with respect to 1 mol of the amic acid of the polyamic acid varnish. If the amount is too small, the imidization rate tends to be smaller than the preferred range, and if the amount is too large, the curing becomes fast and it becomes difficult to cast on the support. Further, an imidization retarder such as acetylacetone may be used in combination as long as the physical properties are not affected.

  It should be noted that the polyamic acid organic solvent solution or the chemical imidizing agent solution to be added thereto is optionally provided with an antioxidant, a light stabilizer, a flame retardant, an antistatic agent, a heat stabilizer, an ultraviolet absorber, or an inorganic Fillers or various reinforcing agents may be added.

  After mixing the polyamic acid varnish obtained by the above method and a chemical imidizing agent, the polyimide film is continuously extruded as a smooth thin film curtain from a slit die, cast on an endless belt, and self-dried by drying and cooling. A gel film having supportability is formed. This gel film is further heat-treated to obtain a polyimide film having the desired mechanical properties.

  In the above method, the viscosity in the die of the resin solution composition in which the polyamic acid varnish and the chemical imidizing agent are mixed is preferably 450 poise or less, more preferably 300 poise or less, particularly preferably 50 to 300 poise. is there. When the viscosity is within this range, the variation in film thickness becomes remarkably high, and it is impossible to obtain a polyimide film that does not generate deformation or wrinkles during storage. Moreover, the bubble entrainment phenomenon is likely to occur, which is not preferable. In addition, when it is 50 poises or less, it is difficult to stably form a film in the present invention using the casting method using a die. This viscosity is a value measured with a B-type viscometer.

  Moreover, it is preferable to control the clearance of the die opening for the purpose of suppressing variations in film thickness and preventing the polyimide film from being deformed or wrinkled during storage.

  Next, the manufacturing process of the polyimide film concerning this invention is demonstrated.

  The production method for imidizing the polyamic acid, which is a polyimide precursor, and finally making a polyimide film product is a belt chamber or drum chamber which is cast-coated on an endless belt or casting drum to obtain a gel film, and a post-heating cure. It is divided into a tenter room.

  An example of the manufacturing process of the polyimide film concerning this invention is shown. First, in the process of the belt chamber, a process of extruding the polyimide precursor mixed with the mixer into a film shape by a T-die is performed, and in the reaction curing chamber, the film-shaped polyimide precursor extruded from the T-die is an endless belt or a casting drum. Form a film on top. The precursor formed in the form of a film is imidized by being heated by a heating means while being moved by the rotation of a belt or a drum. In the belt chamber, the product produced by the reaction, mainly water, organic solvent, etc. evaporate.

  Heating means adjusts the ambient temperature and the rotation speed of the belt or drum in order to prevent the risk of ignition of flammable volatile components evaporated from the resin or to prevent the resin itself from igniting. For example, heating by hot air, hot air, radiant heat, belt heating or the like can be used.

  Through these steps, while the polyimide precursor film is imidized, the film is heated and dried to the extent that it has self-supporting properties, and then peeled off from the endless belt or casting drum to obtain the gel film referred to in the present invention. .

  By the way, in the case of performing imidization while transporting a normal film through the above steps, the shape and surface state of the gel film are best maintained, and the difficulty on the surface such as peeling and wrinkling of the film is prevented, and the film has self-supporting properties. The amount of residual volatiles is measured as an index for producing a film without problems in transportation and processing.

The amount of residual volatiles in the gel film is given by Equation 1.
(AB) × 100 / B... Formula 1
In Formula 1, A and B represent the following.
A: Weight of the gel film B: Calculated from the weight after heating the gel film at 450 ° C. for 20 minutes, and its volatile content is preferably in the range of 5 to 300%, more preferably 5 to 100%. It is in the range, more preferably in the range of 10-80%, most preferably in the range of 15-50%. It is preferable to use a gel film in this range, and if it is removed, the predetermined effect is hardly exhibited.

In addition, using infrared absorption spectrometry, the formula 2
(C / D) × 100 / (E / F)... Formula 2
In Formula 2, C, D, E, and F represent the following.
C: Absorption peak height of 1370 cm ⁻¹ of the gel film D: Absorption peak height of 1500 cm ⁻¹ of the gel film E: Absorption peak height of 1370 cm ⁻¹ of the polyimide film F: Absorption peak of 1500 cm ⁻¹ of the polyimide film The imidation ratio of the gel film calculated from the height is in the range of 50% or more, preferably 80% or more, more preferably 85% or more, and most preferably 90% or more. It is preferable to use a film in this range, and if it is removed, the predetermined effect is hardly exhibited.

  The gel film thus obtained is supplied to a tenter chamber where a heat treatment step is performed, and the ends are fixed and heat treatment is performed in the tenter chamber. For example, the tenter chamber is composed of a heating furnace and a slow cooling furnace, and the film moves in the tenter chamber by moving a pin sheet having a film fixed with pins by rotational driving of a pin conveyor. The gel film is further imidized by gradually heating in a heating furnace that performs thermal curing. In the heating furnace, the temperature is gradually raised from a temperature of usually about 200 ° C. to complete imidation into polyimide.

In order to completely remove residual volatiles and completely convert the polyamic acid to polyimide, it is preferable to heat stepwise and continuously according to a conventional method, and finally use a high temperature for a short time. Specifically, it is preferable to finally heat at a temperature of 400 to 650 ° C., more preferably at a temperature of 450 to 620 ° C. for 10 to 400 seconds. An aromatic polyamide-based polymer substantially composed of units selected from the group consisting of the following structural units.
In the thermal curing step, the completely imidized polyimide film is gradually cooled in a slow cooling furnace.

  In addition, before supplying the gel film to the tenter chamber, a surface treatment solution may be applied to the gel film, or the gel film may be immersed in the surface treatment solution. The surface treatment solution to be treated is also a mechanical property of the film. And it will not be specifically limited if it is a grade which does not deteriorate an external appearance remarkably.

  Moreover, the polyimide film obtained above is heat-treated at 200 ° C. or more and 500 ° C. or less, if necessary, and then wound on a core to form a film roll. Here, the heat treatment can be performed under tension, under a constant length, or in a relaxed state, and can be performed in two or more stages by combining these.

  In addition, the polyimide film can be imparted with better properties by performing a known physical surface treatment such as corona discharge treatment or plasma discharge treatment, or a chemical surface treatment such as primer treatment. Among the above surface treatments, electrical treatment such as corona discharge treatment and plasma discharge treatment is preferred, and corona discharge treatment is more preferred from the viewpoint of productivity and cost.

In the electrical treatment, for the purpose of improving the adhesive strength of the polyimide / metal laminate when the metal layer is laminated on the polyimide film, the discharge density, which is a value obtained by dividing the discharge output by the production rate and the treatment width, is 150 W · min / The electrical treatment is preferably performed at m ² or more, more preferably at a discharge density of 180 W · min / m ² or more, more preferably at a discharge density of 200 W · min / m ² or more. When the discharge density is about 150 W · min / m ² , the adhesive strength required for a base film for a flexible printed circuit board or a base film for high-density mounting is lowered. In this invention, it is preferable that the adhesive strength at the time of laminating | stacking a metal layer through an adhesive bond layer on a polyimide film is 800 N / m or more.

On the other hand, in order to increase the discharge density, it is necessary to increase the discharge output or decrease the processing speed. However, when the discharge output is increased, the amount of static electricity of the polyimide film obtained is increased, and when the processing speed is decreased, the productivity is deteriorated. In order to maintain productivity and adhesive strength against these problems, that is, to reduce the static electricity amount of the polyimide film obtained while maintaining the discharge density, the discharge output per electrode area is 15 W / cm ² or less, preferably It was found that 10 W / cm ² or less, more preferably 8 W / cm ² or less, is good. The electrode area is the area of the effective discharge portion. When the discharge output per electrode area is 15 W / cm ² or more, a charge pattern (static mark) is generated on the polyimide film, and the static electricity cannot be removed by an ion spraying type static eliminator. As a result, static electricity becomes 20 kV or higher.

  The amount of static electricity in the present invention is measured as follows. Roll film is fed out sequentially, and the amount of static electricity at the feeding part and the roll surface part is continuously measured. Moreover, it is desirable that the film obtained above is subjected to static elimination treatment. The static elimination process includes a static elimination method for controlling static elimination output by sensing static electricity on the film surface, a static elimination method using a device in which positive and negative ion generation electrodes and ion suction electrodes described in Japanese Patent No. 2651476 are opposed to each other, and a special feature. Various methods such as a method of performing charging treatment so that the charging polarity of one surface is uniform with respect to one surface described in Kai 2002-289394, and then performing charge neutralization processing from the same surface to remove the charge on the processing surface, etc. These methods can be used in combination.

  Moreover, the film obtained above is slit to an appropriate width, and is rolled up on a core to obtain a product. In winding, in order to reduce the occurrence of uneven thickness or a so-called gauge band on the roll due to uneven thickness in the width direction of the film, winding the film while meandering is also a preferred embodiment. In addition, it is desirable to perform static elimination processing for the purpose of removing static electricity generated during the slitting operation.

  The material of the core used in the above is not particularly limited, and is a fiber reinforced plastic made of a combination of paper, vinyl chloride, or a combination of glass fiber and epoxy resin, paper and phenol resin, carbon fiber and epoxy resin, etc. (FRP), a metal such as stainless steel, a paper core impregnated with a resin, or a resin layer formed on the surface thereof is used as long as it does not impair the effects of the present invention. It is done.

  It is also a preferred embodiment that a sheet material made of a metal material is wound around the outermost layer of the roll. Of course, it is also a preferable embodiment to arrange a sheet material made of a metal material at the same time on the roll end face.

  When it is not preferable that the sheet material made of a metal material is in direct contact with the film roll, the roll may be temporarily covered with a packaging film, and the sheet material made of the metal material may be disposed thereon. As the packaging film, general-purpose polyethylene, polypropylene, polyester or the like is used.

  As a sheet material made of a metal material, a metal foil such as aluminum, copper or stainless steel, a polyethylene film, a polypropylene film, a polyester film or the like laminated with a metal such as aluminum or copper, or a polyethylene film, a polypropylene film or a polyester film. For example, a metal vapor-deposited film obtained by vapor-depositing a metal such as aluminum, chromium, or copper can be used.

  The sealing method of the packaging film is not particularly limited as long as it can substantially prevent or suppress the intrusion of moisture, and a method for adhering or pasting both ends of the film to the core, A method in which both ends are folded into the inner surface of the core and sealed by pressing with a pad of the core, or a sheet material or packaging film made of a metal material is formed into a bag shape and bonded by heating the entrance or the like is arbitrarily used.

  In addition, a buffer material may be installed on the outer periphery of the film roll to protect the film roll, and a buffer material or a pad for preventing end face collapse may be installed on the roll end surface or roll outermost layer. It is also possible to omit the installation. Furthermore, it is also a preferred embodiment that the container is stored in a container such as a cardboard box in order to prevent damage on transportation and to improve handling.

  Embodiments and effects of the present invention will be described below with reference to examples, but the present invention is not limited thereto.

  In addition, the measurement of the electrostatic quantity in an Example used ELECTROSTATIC FIELDMETER FMX-002 (Shimco Japan Co., Ltd.), and rolled out the roll-shaped film sequentially, and measured the electrostatic quantity of the delivery part and the roll surface part continuously. Moreover, the measurement of the adhesiveness in an Example is a polyimide film and electrolytic copper foil (the Mitsui Kinzoku Mining Co., Ltd. make, brand name: 3ECVLP, thickness 35 micrometers), an acrylic adhesive (DuPont company make, brand name: Pyralx LF0100). A three-layered copper-clad laminate is prepared through the measurement, and the copper pattern width is 1 mm and measured at 90 degrees peel according to JIS C-6481.

<Manufacture of polyimide films used in Examples and Comparative Examples>
Polyamic acid DMF solution polymerized using 4,4′-diaminodiphenyl ether, p-phenylenediamine and pyromellitic dianhydride in a molar ratio of 3/4 (solid concentration 20%, viscosity 2800 at 20 ° C.) (Poise) 100 parts by weight of acetic anhydride 200 parts by weight, isoquinoline 100 parts by weight and DMF 190 parts by weight of an imidizing agent 50 parts by weight, quickly stirred with a mixer, extruded from a T-die and stainless steel endless Casting was applied on the belt. The gel was heated on this endless belt at 150 ° C. for 1 minute to obtain a self-supporting gel film. This gel film had a residual volatile content of 30% by weight and an imidation ratio of 85%. This gel film was heated at 250 ° C., 300 ° C., 400 ° C., and 550 ° C. for 15 seconds to obtain a polyimide film having a thickness of 25 μm. This polyimide film was heat-treated at 330 ° C. for 30 seconds with a tension of 5 kgf / m to produce a polyimide film used in Examples and Comparative Examples.

(Example 1)
An aluminum electrode was used for the polyimide film, and a corona discharge treatment was performed with a corona discharge density of 200 W · min / m ² and a discharge output per electrode area of 12 W / cm ² . The polyimide film was slit to a width of 520 mm, and wound on a paper tube having an inner diameter of 6 inches and an outer diameter of 7 inches while performing static elimination treatment on the static eliminator immediately before winding, to produce a roll of 1500 m polyimide film. The amount of static electricity of the polyimide roll immediately after winding was 0.5 kV. Moreover, the static electricity quantity of the polyimide film roll part after 1 week passed was 3 kV, and the static electricity quantity of the film of the delivery part was 7 kV.

(Example 2)
A 1500 m wound polyimide film was prepared in the same manner as in Example 1 except that a corona discharge density of 200 W · min / m ² and a discharge output per electrode area of 8 W / cm ² was performed using a ceramic electrode. A roll was produced. The amount of static electricity of the polyimide roll immediately after winding was 0.5 kV. Moreover, the static electricity amount of the polyimide film roll part after one week passed was 2 kV, and the static electricity quantity of the film of the delivery part was 5 kV. The adhesive strength was 1380 N / m.

(Example 3)
The 1500 m winding polyimide film was prepared in the same manner as in Example 1 except that the corona discharge density was 100 W · min / m ² and the discharge output per electrode area was 12 W / cm ² using an aluminum electrode. A roll was produced. The amount of static electricity of the polyimide roll immediately after winding was 0.5 kV. Moreover, the static electricity amount of the polyimide film roll part after 1 week passed was 4 kV, and the static electricity quantity of the film of the delivery part was 10 kV. The adhesive strength was 480 N / m.

(Comparative Example 1)
The 1500 m winding polyimide film was prepared in the same manner as in Example 1 except that the corona discharge density was 200 W · min / m ² and the discharge output per electrode area was 20 W / cm ² using an aluminum electrode. A roll was produced. The amount of static electricity of the polyimide roll immediately after winding was 0.5 kV. Moreover, the static electricity amount of the polyimide film roll part after one week passed was 12 kV, and the static electricity quantity of the film of the delivery part was 20 kV. The adhesive strength was 1420 N / m.

Claims (5)

A roll-shaped polyimide film obtained by winding a polyimide film around a core, wherein the amount of static electricity is 15 kV or less when the roll-shaped polyimide film is fed out and the amount of static electricity at the feeding portion and the outer peripheral surface of the roll is measured. A roll-shaped polyimide film characterized by that. The roll-shaped polyimide film according to claim 1, wherein static electricity between the feeding portion and the outer peripheral surface of the roll is 10 kV or less. The roll-shaped polyimide film according to claim 1 or 2, wherein the adhesive strength of the polyimide / metal laminate obtained by laminating the polyimide film and the metal layer via an adhesive layer is 800 N / m or more. The polyimide film according to any one of claims 1 to 3, wherein an electrical treatment is performed on both sides or one side of the polyimide film. The polyimide film according to claim 4, wherein the electrical treatment is performed by at least one of corona treatment and plasma treatment.