JP5241983B2 - Film roll body and method for producing film roll body - Google Patents

Description

  The present invention relates to, for example, a film roll body obtained by winding a film used for a magnetic tape or a packaging material into a roll, and a method for producing the film roll body.

  In the case of winding a film around a roll body, it has been conventionally known that a surface treatment is applied to a part of the film in the width direction in order to prevent end face deviation and meandering of the film. Examples of the surface treatment include embossing, formation of striped convex portions, and charging treatment. By these surface treatments, the friction coefficient between films increases, the adhesiveness between films becomes high, and the shift | offset | difference and meandering of a film can be prevented.

  Among these surface treatments, a charging method is disclosed in, for example, Japanese Patent Application Laid-Open No. 9-20296. In Japanese Patent Laid-Open No. 9-20296, the discharge electrode is brought into contact with or close to the other surface of the film in which one surface is in close contact with the grounded conductive roller, and the film is charged. It is disclosed that both surfaces of a film are charged by peeling from the surface of a ground conductive roller.

  However, in the invention described in Japanese Patent Application Laid-Open No. 9-20296, the air entrained between the film layers when the film is wound into a roll shape due to the close contact of the charging unit for preventing the winding deviation is As a result, it is prevented from escaping from the end of the film, which causes eccentricity and wrinkles during rotation of the film roll body.

  In particular, when processing with a vacuum process such as when a film roll body is deposited, the air entrained between the film layers is released at a stroke in the exhaust process in the vacuum machine, so there is a problem that the end face of the film roll body is greatly displaced. There arises a problem that the film snakes left and right when the film is unwound or unwound from the film roll in the vapor deposition machine. For this reason, a film roll body processed by a vacuum process, particularly a film roll body for vacuum deposition processed at a high vacuum, has a strong adhesion and allows air to escape appropriately between the layers of the film roll. There has been a demand for a charging method that can perform the above-described process.

  On the other hand, Japanese Patent Application Laid-Open No. 51-71351 discloses a method for ensuring the air escape from the end of the film roll by subjecting it to surface treatment such as charging and hot air in the longitudinal direction of the film in synchronization with the rotation of the film roll. A technique for forming intermittently is disclosed.

  The technique described in Japanese Patent Application Laid-Open No. 51-71351 is shown in FIG. As shown in FIG. 4, when the film 4 is wound up as the film roll body 1, the film 4 is intermittently charged by the needle-like electrode 7 connected to the high voltage power source 9. Further, the rotational speed detection device 15 of the film roll body 1 detects the rotational speed of the film roll body 1, and the control device 12 controls the high voltage output / stop of the high voltage power source 9 in synchronization with the rotation of the roll.

  However, in this method, since the surface treatment by the charging treatment is performed in synchronization with the rotation of the winding roll, the control device 12 is complicated and expensive. Furthermore, since the high voltage application cycle is changed as the roll diameter of the film roll is increased, switching of the high voltage circuit is required, the system is complicated, and the high voltage switching unit is liable to be damaged.

  In addition, since a voltage is intermittently applied to the needle electrode 7, dust adheres to and solidifies on the needle electrode, and the needle tip is oxidized, which requires much labor for maintenance and the shape of the needle tip due to corrosion. As a result, the discharge state changes with time, resulting in difficulty in control.

  Moreover, since each film layer closely_contact | adheres at the specific position of the circumferential direction of a film roll, when the winding diameter is large, the distribution difference of air arises in the circumferential direction, and a film roll foam is disturbed. Specifically, as shown in FIG. 4, the film roll has uneven hardness between the close contact portion 16 and the non-contact portion 17 of the film, and can be wound into a polygonal shape. This causes tension fluctuations and causes tears and wrinkles.

  As described above, the conventional surface treatment technique is not sufficient as a technique for preventing the roll deviation of the film roll body.

Problems to be solved by the invention

  The object of the present invention is to eliminate the disadvantages of the prior art, effectively prevent the end face shift and the like by a small charge processing part, make problems such as tearing difficult, and problems such as eccentricity, wrinkles, roll deformation, etc. There are provided a film roll body having no film and a method for producing an inexpensive and stable film roll body.

Means for solving the problem

  The configuration of the present invention for solving the above-described problems is as follows.

The film roll body of the present invention has, at the end in the width direction of the film wound in a roll shape, a charging treatment section having a difference between the maximum width and the minimum width of 10 mm or less and a width of 20 mm or less. The processing unit is intermittently present in the longitudinal direction of the film at a predetermined cycle. In the charging processing unit, the charges on the front surface and the back surface of the film are given reverse polarity, and the charges on the front and back surfaces of the overlapping film are reversed. It is polar .

Film roll of the present invention, preferably, the ratio of a static-processing unit, in the longitudinal direction, characterized in that 10 to 80 percent in one cycle.

The method for producing the film roll body of the present invention comprises:
In the longitudinal direction of the film, the edge of the film is charged with a DC power source intermittently at a predetermined cycle so that the charges on the front and back surfaces of the film have opposite polarities , The charge on the front surface and the back surface of the overlapping films is opposite in polarity, and the time ratio for performing the charging treatment within one period is 10 to 80%.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments along with the principles of the present invention will be described below with reference to the drawings.

  The film roll body of the present invention has an electrification processing part in which the difference between the maximum width and the minimum width is within 10 mm in at least part of the width direction of the film wound in a roll shape.

  As a result of the study, the inventors have not only caused spots in the charging process itself in the conventional charging method as described above, but also when the film is wound to form a film roll body, the same position of the film roll body is obtained. In this case, the potential of this portion increases significantly, and as shown in FIG. 8, a discharge 22 is generated from the charged portion to the surrounding non-charged portion, causing fluctuations in the width of the charged portion. I found out.

  If the difference between the maximum width and the minimum width of the charging portion exceeds 10 mm, it is impossible to simultaneously realize a strong displacement prevention and air escape from the end portion. By making the difference between the maximum width and the minimum width of the electrification processing section within 10 mm, it is possible to effectively prevent the deviation of the end face of the film roll body and to prevent the film roll body from decentering or wrinkling, the roll deformation, etc. .

  One embodiment of the film roll of the present invention is shown in FIG. 1, and one embodiment of the film of the present invention is shown in FIG. The charging processing unit 2 of the film roll body 1 is provided to prevent deviation. The difference between the maximum width Y and the minimum width X of the charging processing unit 2 is within 10 mm. Here, the width of the electrification processing part is the length of the electrification processing part in a direction perpendicular to the film longitudinal direction. When the length of the charging portion is 1 m or longer, the width of the charging processing portion is confirmed over an arbitrary 1 m in the longitudinal direction of the film, the difference between the maximum width being Y and the minimum width being X. Ask for. When the length of the charging portion is less than 1 m, the difference between the maximum width and the minimum width between charging portions in one cycle is obtained.

  The width and state of the charging processing unit can be confirmed by visualizing the charging processing unit by sprinkling powder or liquid in close contact with a charged portion such as toner used in a printer or a copier on the film.

  Further, by placing a film on a conductive plate and sprinkling toner or celestial pollen on the film, it is possible to clearly visualize and discriminate a portion that is strongly charged by the charging process.

  When toner adheres to other than the charging processing unit, the charging processing unit and the non-charging processing unit can be determined based on the toner adhesion amount, and the boundary between the charging processing unit and the non-charging processing unit can be confirmed. The maximum width, minimum width, and lengthwise period of the charging processing unit can be measured using this boundary as a mark.

  In the present invention, it is preferable that the charging processing unit is intermittently present at a predetermined period in the longitudinal direction of the film.

  Further, in the present invention, the ratio of the charge processing portion is preferably 10 to 80% in one cycle in the longitudinal direction.

  The ratio of the charged portion 2 of the film 4 in one cycle is obtained by dividing the length E of the charged portion by the cycle S as shown in FIG. When the film is wound up, if the charging process is intermittently performed at a predetermined period and the time ratio of performing the charging process within one period is 10 to 80%, the resulting film roll body is charged. The proportion of parts is 10 to 80% in the longitudinal direction.

  If the length E of one cycle is smaller than the circumferential length of the film roll and the total length of the film is sufficiently large relative to the cycle, the probability that the charging portions overlap with each other on the average of the entire film roll body is the charging processing portion that occupies one cycle. The ratio is approximately the same, and overlaps at a ratio of approximately 10 to 80% in the winding direction between adjacent upper and lower layers on the film roll body.

  If the proportion of the charged portion is less than 10%, the portion where the charged portion overlaps becomes too small, and the effect of preventing the original deviation may be lost. Conversely, if the proportion of the charged portion exceeds 80%, the charged portions are almost overlapped, and even if the deviation can be prevented, the air does not escape and the foam of the film roll body is disturbed. Lamination may cause unnecessary discharge in uncharged parts.

  In the present invention, the ratio of the charged portion is more preferably 40 to 60% in one cycle and most preferably 50% in one cycle in the longitudinal direction. When the ratio of the charge processing portion is 40 to 60% within one cycle, the effect of air removal and the effect of preventing deviation are most balanced.

  Further, in the case of a film having a relatively large friction coefficient between film layers, the charging process cycle is made larger than the roll circumference of the innermost layer so that one or more charging process regions are not included in each layer of the film. May be. This is because the adhesive force works with a strength inversely proportional to the square of the distance if there is a vertically charged film even if it is several layers apart. When the charging process cycle is made larger than the innermost layer roll circumference, the charging process cycle is preferably about 1 to 20 times the innermost layer roll circumference, and the proportion of the charged portion in one cycle is 10 to 10 times. 60% is preferable.

  In the present invention, the electrification processing section is not particularly limited, and it is sufficient that the electrification processing section is at least one place in the width direction of the film. When the surface of the film to be applied is strongly charged by the charging process, the metal is not uniformly bonded to the film, and therefore, it is preferable that the edge part that does not interfere with the subsequent process is charged.

  Further, when the width of the film roll body is wide, the accompanying air becomes large. Therefore, it is preferable to perform charging treatment at two or more places in the width direction such as both ends where the film is easily displaced.

  In the present invention, the film includes any polymer film such as a thermoplastic film, and a thermoplastic film is particularly preferable.

  Further, in the present invention, the film is preferably a film that is easy to hold a charge and that does not dissipate the applied charge within a short time (the time from when the charge is applied until it is wound). Is more preferable.

  Furthermore, the present invention is preferably applied to a film having a high air barrier property.

  In the present invention, the film is, for example, polyester represented by polyethylene terephthalate, polyethylene-2,6-naphthalate, etc., polyvinyl typified by polyethylene, polypropylene, etc., polyvinyl chloride, polyvinylidene chloride represented by polyvinylidene chloride, etc. , Polyamide, aromatic polyamide, polyphenylene sulfide, and the like, and polypropylene film and polyethylene terephthalate film are particularly preferable.

  The film roll body of the present invention can be applied not only to a thermoplastic resin film but also to a polymer film melted by a solvent.

  The film roll body of the present invention is preferably applied to a film immediately after film formation used for applications such as vapor deposition, but further, for use in magnetic tape, capacitors, packaging materials, circuit boards, etc. Or it can apply preferably also to the film in which secondary processing, such as a printing process, a vapor deposition process, and a lamination process with another kind of film, was given.

  As the film roll body of the present invention, a thick film of 0.2 to 0.5 mm, a film of 10 to 30 μm, and an ultrathin film of 1 to 3 μm can be used, and the film thickness is not particularly limited. .

  The film roll body of the present invention can be suitably used for a wide range of applications such as magnetic tapes, packaging materials, and capacitors. When used for magnetic tapes and capacitors, a thin film is used. Moreover, the film roll body of the present invention is preferably used for a packaging material, in particular, a film used for a packaging material for food such as confectionery requiring air and moisture barrier properties.

  An example of the manufacturing method of the film roll body of this invention is shown in FIG.

  The film 4 is conveyed from the left to the right by a plurality of guide rollers 5 including metal rollers, and is wound up as a film roll body. In this figure, the film is sandwiched between a guide roller and a discharge electrode 6 (here, a ring-shaped roller which is a ring-shaped discharge electrode) disposed as a nip roller, and is charged.

  The ring-shaped discharge electrode 6 is connected to a high voltage power source 9, and a guide roller such as a conductive roller is usually grounded.

  In the method for producing a film roll body of the present invention, it is preferable to use a ring electrode as the discharge electrode when periodic voltage application is performed. The needle-shaped electrode is severely corroded with respect to a periodic electric field change, whereas the ring-shaped electrode has a small electric field concentration and hardly undergoes deterioration with respect to the periodic electric field change.

  In the method for producing a film roll body of the present invention, it is sufficient if the film can be stably charged, and there is no restriction on the dimensions of the ring-shaped electrode, but it may be difficult to take the clearance of the discharge gap part even if it is particularly large, The ring diameter is preferably about 50 to 200 mm. The ring width of the ring-shaped electrode is preferably about 5 to 50 mm, particularly about 10 to 20 mm in order to make the charging portion as small as possible. This is because 20 mm is sufficient as the charging width necessary for preventing the deviation, and if it is 10 mm or more, the ring can be easily formed.

  Moreover, it is preferable to use what gave the ring peripheral surface the process which gives a curvature to a ring-shaped electrode in order to prevent the spark from an electrode side surface to a film surface.

  Furthermore, in the manufacturing method of the film roll body of the present invention, when the film is torn, it has a conductive rubber on the surface of the ring electrode in order to prevent an excessive current from flowing due to contact between the metal rolls. Preferably, the surface of the ring electrode is more preferably covered with conductive rubber. If the surface of the ring electrode is covered with conductive rubber, the width of the ring electrode becomes almost the same as the width of the charge processing part, and stable charge processing can be performed. Can be reduced.

The conductive rubber layer preferably has a resistivity of 10 ⁴ to 10 ⁸ Ωcm and a thickness of about 1 to 10 mm.

  Further, as shown in FIG. 9, at least a part of the side surface of the ring-shaped electrode 6 is covered with an insulator (side surface coating 25) having an electric resistance equal to or higher than that of the conductive rubber. Is preferred. This is to prevent unnecessary discharge from the metal portion on the side surface of the electrode to the film. Thereby, the fluctuation | variation of the charging process part width | variety can be made smaller.

  Moreover, in the manufacturing method of the film roll body of this invention, when a film is torn by providing the circuit which interrupts | blocks an excessive current, it can also prevent that an excessive electric current flows by the contact of metal rolls.

  In the method for producing a film roll body of the present invention, the charging process is performed at a predetermined cycle. In the present invention, the term “predetermined period” means that the charging process is performed or stopped at a predetermined period. A constant period may be used throughout the entire length of the film roll body, or the period may be changed step by step depending on the winding diameter. It is preferable because it can be used easily and stably over a long period of time.

  By making the period of the charging process constant, for example, as shown in FIG. 3, the charging process unit 2 naturally increases the circumferential length of the film roll body as the winding diameter of the film roll body changes. The part moves in the circumferential direction and is randomly arranged with respect to the circumferential direction of the film roll body 1. When the charge processing portion of the film roll body is random, a portion where the air does not easily escape and a portion where the air easily escapes are dispersed, so that local deformation of the film roll body can be prevented. Since the film roll body 1 obtained in this way has uniform wrinkles and no eccentricity, it can prevent meandering and tearing during unwinding in a subsequent process.

  Furthermore, since the charging unit is randomly arranged with respect to the circumferential direction of the film roll body 1, it is possible to prevent the charging part from being stacked at the same position of the film roll body and to cause a significant increase in charging. As shown in FIG. 8, it is possible to prevent the occurrence of the discharge mark 22 on the non-charged portion.

  In the film roll manufacturing method of the present invention, in order to charge the film 4 at a predetermined cycle, it is preferable that the signal generated from the pulse generator 11 shown in FIG. can do.

  In the method for producing a film roll body of the present invention, the preferred charging treatment application period is in the range of 0.05 to 1.5 (m). If this value is smaller than 0.05, the clearance through which air escapes becomes smaller, and if it is larger than 1.5, the probability that a portion where charged portions overlap will be 10 to 80% tends to be smaller than 1.

  In the method for producing a film roll body of the present invention, as shown in FIG. 5, the gear-shaped ring electrode 8 can be used as the discharge electrode, and the voltage can be intermittently applied at a constant period. The gear-shaped ring electrode 8 is preferably formed by forming irregularities in the circumferential direction with a constant pitch on the ring-shaped electrode so that the height of the protrusion is sufficiently larger than the discharge gap. In this case, the DC high voltage power supply 13 can be used as the voltage application means for the charging process.

In the method for producing a film roll body of the present invention, the voltage that can be charged to the film means a voltage that is sufficiently higher than the discharge start voltage determined by the thickness δ and relative dielectric constant ε _r of the film. The voltage value is preferably about 2 to 10 times the discharge start voltage when a ring-shaped electrode as shown in FIG. 3 is used. The discharge start voltage can theoretically be obtained from the following two equations.

Ring electrode and the gap between the films formula _{V g = (V a -V c} ) Z / (δ / ε r + Z) of the voltage _{V g} applied to the (discharge gap) (1)
(Where V _a is the applied voltage, V _c is the charging potential on the film surface, and Z is the discharge gap.)
First-order approximate expression of discharge breakdown voltage V _b in the air gap according to Paschen's law V _b = 312 + 6.2Z (2)
The discharge start voltage is obtained as a value of V _a −V _c determined when V _g = V _b in equations (1) and (2). If the influence of the charging potential of the film is ignored, the applied voltage can be obtained by the following equation.

V _a = 312 + 6.2δ / ε _r + 88√ (δ / ε _r ) (3)
When charging periodically, if the voltage and current at the time of discharge are not changed, and set to a constant voltage that is 2 to 10 times the discharge start voltage first, the voltage is reduced and discharged by voltage control. Is preferable because there is no fear of becoming unstable.

  In order to stably discharge, the ring electrode is preferably pressed against a counter electrode such as a grounded conductive roller with a predetermined force. Thereby, the aforementioned discharge gap is automatically formed.

  In the method for producing a film roll body of the present invention, when charging is performed intermittently, in the film roll body, in order to prevent the front and back surfaces of the films overlapping vertically from having the same polarity, either positive or negative It is preferable to perform processing by applying a rectangular wave voltage of the polarity. Also, the waveform of the rectangular wave voltage may be a substantially rectangular wave, and may be a trapezoidal wave shape with gentle rise and fall, or a half wave rectified shape of a sine wave. It is preferable to use a rectangular wave because the voltage stop ratio can be easily controlled.

  In the method for producing a film roll body of the present invention, it is preferable that the charging treatment is performed by charging the film to opposite polarities on both sides. When the film is charged on both sides, in the film roll body, the film firmly adheres to the upper and lower layers in the charging processing section.

  Further, in the case of a film having a conductive layer on one side, such as a vapor deposition film, it is sufficient to charge only the insulating surface as necessary. That is, when a film having a conductive layer on one side is formed into a film roll body, an electric charge is induced by electrostatic induction on the conductive layer in contact with the charged portion, and an adhesion force works.

  As shown in FIG. 3, charging a film without a conductive layer on both sides can be easily realized by charging the film on a conductor having a low potential, such as a ground conductor, and then peeling the film from the conductor. This is because, due to the charge on the film surface applied on the conductor, a discharge occurs between the conductor and the film back surface at the time of peeling, and a charge having a polarity opposite to that of the surface is automatically applied to the film back surface.

  In the method for manufacturing a film roll body of the present invention, it is preferable that the conductive roller is a metal roller made of steel, aluminum, or the like as a shaft member, and a surface of which is made of a plating, a conductive coating, or a metal base. . At this time, for the sake of safety, it is preferable that the conductive roller is grounded in order to apply a voltage to the conductive roller from the ring-shaped discharge electrode.

  In the film roll manufacturing method of the present invention, the film is supplied from, for example, a film discharge machine such as a melt roll source shown in FIG. 6 or a raw roll used in a slitter shown in FIG. .

  6 and 7 illustrate a film winding mechanism that can be used in the method for producing a film roll of the present invention. The film roll body of this invention can wind up a film roll body, for example by driving a pressure roller or a winding roller with an electric motor. FIG. 7 includes a film supply mechanism A ′ composed of a raw fabric roll and a transport unit B ′ composed of a guide roller.

  As described above, the inventors were able to obtain a film roll body in which the width of the charged portion is small and does not fluctuate by intensively studying the method for producing the film roll body. The variation in the width of the charged portion of the film roll obtained in this way is 10 mm or less, and the width of the charged portion is preferably within 20 mm. As a result, wrinkles and shifts can be prevented while avoiding unnecessary charging of the processed portion in the subsequent process.

  Furthermore, the film roll body wound up by the production method of the present invention has a strong adhesive force and does not shift during evacuation with a vapor deposition machine, so the film roll body of the present invention is particularly excellent as a raw material for vapor deposition. .

Hereinafter, the present invention will be specifically described with reference to examples. In addition, the evaluation methods in the following examples and comparative examples are as follows. A polypropylene film or a polyester film was used as the film.
(1) Charging treatment After the charged portion was visualized with toner, the width of the charged portion was measured and evaluated according to the following criteria. A ruler was used to measure the width.
Width of charged portion ○: 15 mm or less, Δ: Larger than 15 mm to 20 mm or less, X: Large difference from large amount to 20 mm and minimum width ○: 10 mm or less, X: Larger than 10 mm (2) Film winding shape The end face deviation measured and evaluated according to the following criteria: ○: 0.5 mm or less, Δ: greater than 0.5 mm to 2 mm or less, x: greater than 2 mm Also, the state of the film roll, The degree of eccentricity was evaluated in the following two stages.
Degree of wrinkle generation ○: Good, △: Acceptable, ×: Degree of eccentricity below the product level ○: Good, △: Eccentric and large tension fluctuation, ×: Eccentric torn tearing (3) Deviation amount in vacuum machine Original in vapor deposition machine The film roll body was put into a vacuum machine assuming anti-deviation, and the situation where deviation occurred due to evacuation was evaluated according to the same evaluation criteria as the end face deviation.

Example 1
With the manufacturing method illustrated in FIG. 3, a polypropylene film having a width of 2 m and a thickness of 29 μm was wound up to a length of 4500 m at a film speed of 85 m / min. A ring-shaped electrode coated with a conductive neoprene rubber layer having a diameter of 100 mm, a width of 10 mm, a rubber thickness of 2 mm, and an electric resistivity of 2 × 10 ⁶ Ωcm in the shape of FIG. 9 is used, and a current value of −0.22 mA (applied) The film was subjected to charging treatment intermittently under the conditions of 10 Hz (period of 0.1 second) and 50% of the time ratio of voltage application. The results are shown in Table 1.

  As shown in Table 1, the film roll body thus obtained has a stable width of 10 to 11 mm (the difference between the maximum width and the minimum width is 1 mm) and is being wound with a strong adhesion. There was no misalignment of the end face or in the vacuum machine.

  In addition, by setting the ratio of the charge processing portion of the film roll body to 50%, air can be removed from the end portion, and there is no wrinkle and eccentricity is about 0.1 mm, so that fluctuation in tension can be minimized. An ideal film was obtained as the raw material for vapor deposition.

Comparative Example 1
A polypropylene film having a width of 2 m and a thickness of 29 μm was wound up to a length of 4500 m at a film speed of 85 m / min in the same manner as in Example 1 by the production method illustrated in FIG. Needle-like electrodes are placed at both ends, and a voltage of -7 kV is applied to the needle-like electrodes so that the lengths of the charged and non-charged treatment parts are equal for four locations per rotation of the film roll body. The charging process was intermittently performed in synchronization with the rotation. The results are shown in Table 1.

  The current value of the needle electrode was unstable, and as a result, the difference between the maximum width and the minimum width of the charging portion exceeded 10 mm and was about 15 mm. Accordingly, although the charging treatment width was initially set to 10 mm, there were portions where the width of the charging treatment portion exceeded 20 mm depending on the location, resulting in narrowing the portion to be vapor-deposited. Further, since the discharge of the needle-like electrode was unstable and the charge at this portion was very small, a displacement exceeding 30 mm occurred in the surface layer during vacuuming during the vapor deposition process.

  Although air deflation between the film layers was good and no wrinkle was generated, charging was performed in synchronism with rotation, and as a result, tension fluctuation due to eccentricity was observed as compared with Example 1.

Example 2
A film was continuously produced by the production method shown in Example 1 except when stopped. Even after one year of use, there was no noticeable damage to the electrode roll, and the applied voltage and applied current value of the ring-shaped discharge electrode did not vary greatly. Further, the state of the electrified portion of the obtained film roll and the film winding shape did not vary greatly and were good.

Comparative Example 2
A film was continuously produced by the production method shown in Comparative Example 1 in the same manner as in Example 2 except when it was stopped. The current value of the needle-like electrode was unstable, and as a result, the difference between the maximum width and the minimum width of the charging portion exceeded 10 mm and was about 20 mm. Due to the dust adhering to the electrode, cleaning is required once a week, and the tip of the electrode corrodes to an eye when used for 3 months, and the difference between the maximum width and the minimum width of the charged portion is further increased. There was a need for replacement. After this, the same acicular electrode was used for 6 months, but there was significant corrosion as before the replacement, and it was necessary to increase the voltage to 1.5 times the start in order to obtain the effect of preventing end face displacement. However, the contact point deteriorated due to high voltage switching, and abnormal noise was generated from the power supply. Need to repair.

Example 3
With the production method shown in Example 1, a stretched polyester film having a width of 3.5 m and a thickness of 10 μm was wound up to a length of 90000 m at a film speed of 200 m / min. The value of the current flowing through the electrode during the charging process is -0.1 mA (applied voltage -2.0 kV), and the charging process is intermittently performed under the conditions of 50 Hz (0.02 sec cycle) and 60% of the time ratio of voltage application. Went.

  Since the winding diameter is large, evaluation in a vacuum machine was not performed, but the other evaluation items were as good as in Example 1.

Comparative Example 3
With the production method shown in Comparative Example 1, a stretched polyester film having a width of 3.5 m and a thickness of 10 μm was wound up to a length of 90000 m at a film speed of 200 m / min. Needle-like electrodes are placed at both ends, a voltage of 10 kV is applied to the needle-like electrodes, and the lengths of the charged and non-charged treatment parts are equalized at four locations per rotation of the film roll body. The charging process was intermittently performed in synchronization with the rotation.

  As shown in Table 1, the current value was controlled so as to minimize the end face displacement. However, it is necessary to increase the voltage to 10 kV, and the width of the charged portion exceeds 30 mm. The difference was about 20 mm, exceeding 10 mm. In addition, since the winding diameter was large, the eccentricity was large and the tear did not break, but the tension fluctuation was significant, resulting in wrinkling.

Effect of the invention

  According to the present invention, it is possible to simultaneously realize strong prevention of displacement and air escape from the end portion, and it is possible to obtain a film roll body free from displacement, wrinkles, deformation, and eccentricity of the end surface.

  According to the method for producing a film roll body of the present invention, a film roll body without end face displacement, wrinkles, eccentricity, or deformation is produced by a charging process that is stable over a long period of time with little deterioration of the electrode and has good maintainability. be able to.

  Since the film roll body of the present invention has a strong adhesion and does not shift when evacuated with a vapor deposition machine, it is particularly excellent as a raw material for vapor deposition, and is suitably used for a wide range of applications such as magnetic tape, packaging materials, and capacitors. .

It is a front view which shows one Example of the film roll body of this invention. It is an external view of the film which shows one Example of the film of this invention. It is the block diagram which showed an example of the manufacturing method of the film roll body of this invention. It is the block diagram which showed the manufacturing method of the conventional film roll body. It is the block diagram which showed another example of the manufacturing method of the film roll body of this invention. It is the block diagram which showed another example of the manufacturing method of the film roll body of this invention. It is the block diagram which showed another example of the manufacturing method of the film roll body of this invention. It is a perspective view of the film roll body manufactured with the conventional charging method. It is sectional drawing which showed an example of the ring-shaped electrode used with the manufacturing method of the film roll body of this invention.

1: Film roll body 2: Charging portion 3: Winding roller 4: Film 5: Guide roller 6: Ring-shaped discharge electrode 7: Needle-shaped discharge electrode 8: Gear-shaped ring electrode 9: High-voltage power supply 10: High-voltage amplifier 11: Pulse waveform generator 12: Control device 13: DC high-voltage power supply 14: Pressure roller 15: Film roll rotation speed detection device 16: Film contact portion 17: Film non-contact portion 18: Melt discharge source 19: Solidification drum 20 : Raw roll 21: Slit blade 22: Discharge mark 23: Bearing 24: Conductive rubber layer 25: Side coating A, A ': Film supply mechanism B, B': Conveying part S: Period E of charging process part E: Charging Length X of processing portion: Maximum width of charging processing portion Y: Minimum width of charging processing portion

Claims (19)

At the end in the width direction of the film wound in the form of a roll, there is a charging processing section having a difference between the maximum width and the minimum width of 10 mm or less and a width of 20 mm or less, and the charging processing section is predetermined in the film longitudinal direction. In the charge processing section, the charge on the front and back surfaces of the film is imparted with reverse polarity, and the charge on the top and bottom surfaces of the film overlapping each other has a reverse polarity. Film roll body.
2. The film roll body according to claim 1, wherein the ratio of the charge processing portion is 10 to 80% in one cycle in the longitudinal direction.
3. The film roll body according to claim 1, wherein a ratio of the electrification processing portion is 40 to 60% in one cycle in the film longitudinal direction.
The film roll body according to any one of claims 1 to 3, wherein a period of the charging treatment is shorter than a circumference of the innermost layer of the film roll body.
The film roll body according to any one of claims 1 to 4, wherein the film is a thermoplastic film.
The film roll body according to any one of claims 1 to 5, wherein the film is an insulating film.
The film roll body according to any one of claims 1 to 6, wherein the film is a polypropylene film or a polyethylene terephthalate film.
The film roll body according to any one of claims 1 to 7, wherein the film is a raw material for vapor deposition.
The film roll body according to any one of claims 1 to 8, wherein the film is a packaging material film.
In the longitudinal direction of the film, the edge of the film is charged with a DC power source intermittently at a predetermined cycle so that the charges on the front and back surfaces of the film have opposite polarities , The manufacturing method of the film roll body which makes the electric charge of the surface and back surface of an overlapping film reverse polarity, and the time ratio which performs this charging process within one period is 10 to 80%.
The method for producing a film roll body according to claim 10, wherein the period of the charging treatment is constant.
The manufacturing method of the film roll body of Claim 10 or 11 whose time ratio which performs the charging process within one period is 40 to 60%.
The manufacturing method of the film roll body in any one of Claims 10-12 which performs an electrification process using a ring-shaped electrode.
The manufacturing method of the film roll body of Claim 13 in which the said ring-shaped electrode has conductive rubber on the surface.
The manufacturing method of the film roll body of Claim 13 or 14 with which at least one part of the side surface of the said ring-shaped electrode is coat | covered with the material which has a resistance value equivalent to the said conductive rubber or it.
The manufacturing method of the film roll body in any one of Claims 10-15 which performs an electrification process on the other surface of a film in the state which one surface of the film contact | adhered to the electroconductive roller.
The period of the charging process is 1 to 20 times the circumference of the innermost layer of the film roll body, and the ratio of the charging process part to be set to one period is 10 to 50%. Method for producing a film roll body.
The method for producing a film roll body according to any one of claims 10 to 17, wherein a period of the charging treatment is 0.05 to 1.5 (m).
The film roll according to any one of claims 10 to 18, wherein when the relative dielectric constant of the film is εr and the film thickness is δ (µm), the applied voltage is 2 to 10 times the voltage Va determined by the following equation. Body manufacturing method.
Va = 312 + 6.2δ / εr + 88√ (δ / εr)

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