JP4710333B2 - Temporary adhesive sheet, method for temporary adhesion of sheet, and substrate with provisionally adhered sheet. - Google Patents

Description

  The present invention relates to a charged sheet, a method for producing the same, a method for charging an electrically insulating sheet, and a substrate with a temporarily bonded sheet.

  Up to now, the possibility of temporarily or occasionally peeling a sheet such as paper or film on various objects such as a wall surface or a bulletin board is undeniable. A method using an adhesive such as an adhesive or a pressure-sensitive adhesive tape or a pressure-sensitive adhesive, or a method of pressing a sheet with a hook or a magnet has been used. However, when using an adhesive, etc., when the adhesive or the like moves to various objects such as a wall surface or a bulletin board (hereinafter referred to as a temporary bonding destination base material) and remains after the sheet is removed, or conversely, the sheet is removed. However, there were problems such as fouling of the substrate surface and sheet. Moreover, in the thing using a cage | basket and a magnet, there existed a problem that the material of a temporary attachment destination base material was restricted. In addition, when using a sheet coated with adhesive in advance, such as sticker paper, the sheet will not stick to other objects before being applied to the temporary bonding destination substrate, and dust may be present on the adhesive. In some cases, it is necessary to attach release paper or the like to the sticker paper for the purpose of preventing adhesion and deterioration of adhesiveness.

  On the other hand, in a process of bonding a plurality of electrically insulating sheets, a method is known in which a plurality of electrically insulating sheets are charged with each other and an adhesion force (Coulomb force) by this charging is used (for example, non-patent) Reference 1).

  According to Non-Patent Document 1, as shown in FIG. 7, the sheets 5d and 5e to be brought into close contact are placed on the upper and lower portions of the insulating base material 5c, which is the temporary bonding destination base material B. 5c and the sheets 5d and 5e to be brought into close contact with each other, the electrostatic charging electrodes 5a and 5b to which a DC high voltage of opposite polarity is applied are arranged facing each other, and the discharge needles of the upper and lower electrostatic charging electrodes A structure is disclosed in which the upper and lower sheets 5d and 5e are brought into close contact with the insulating base material 5c by charging the upper and lower sheets with opposite polarities by the ions 301 and 302 generated by the above.

  Further, according to Non-Patent Document 1, as shown in FIG. 8, a sheet 5 g having a conductive object such as a copper plate or a roller (conductive base material 5 f which is a conductive object C) as a temporary bonding destination base material B is used. When an electrostatic charging electrode 5a to which a DC high voltage is applied is arranged opposite to the sheet 5g on the grounded conductive object C, the sheet is charged by the ions 302 generated by the discharge needle. Thus, a configuration in which the sheet 5g is brought into close contact with the temporary bonding destination base material B is disclosed.

  According to the method disclosed in Non-Patent Document 1, since the pressure-sensitive adhesive is not used, it is possible to suppress the remaining of the pressure-sensitive adhesive, the scratch of the temporary adhesion destination base material at the time of peeling, and the like.

However, there are the following problems in the pasting method using such conventional charging.
(1) When the temporary adhesion destination base material is an insulator, when the sheets are bonded, the electrostatic charging electrodes 5a and 5b are sandwiched between the sheets 5d and 5e and the temporary adhesion destination base material B as shown in FIG. Need to be placed. Accordingly, it is difficult to apply the temporary bonding of a sheet using an existing wall or a bulletin board as a temporary bonding destination base material. On the other hand, even if the temporary bonding destination base material B is a conductor C, as shown in FIG. 8, the electrostatic charging electrode 5a is required when performing temporary bonding, and is not suitable for performing simple temporary bonding.
(2) In the case where the temporary adhesion destination base material is an insulator and the temporary adhesion destination base material and / or the sheet is thick, the charge charged by the ions generated by the discharge needles of the upper and lower electrostatic charging electrodes is (non-patent Although it is not clearly described in Reference 1, since the temporary adhesion destination base material and the sheet are insulative, the electric charge does not move in the thickness direction of the sheet). Fixed to each outer surface. For this reason, when another conductor, a charged object, or the like approaches the vicinity of the outer surface, it is easy to be affected by a decrease in the adhesion force due to a newly generated electric field between them. When the temporary adhesion destination base material is a conductor, the charged electric charge exists on the outer surface of the sheet and is similarly affected. Further, at this time, a potential difference is generated between the outer surface (the surface opposite to the contact surface) of the sheet and the contact surface (conductor surface), and an electric field is generated near the outer surface (due to the charged charge on the outer surface). This electric field causes ions in the air to be attracted to the outer surface of the sheet, neutralizing the charged charges, resulting in a problem that the unadhered force decreases with time, and attracts dust or the like to impair the aesthetic appearance of the sheet. In particular, it is not suitable for pasting when the temporary adhesion destination base material and / or the sheet is thick.
(3) When the temporary bonding destination base material has a complicated shape such as irregularities, it is difficult to apply the electrostatic charging electrode with a simple structure and it is difficult to apply.

  For these reasons, the method for laminating an electrically insulating sheet by static electricity disclosed in Non-Patent Document 1 is used only for limited applications such as laminating a base material and a sheet in a process such as a papermaking process. It was.

  Further, when the sheet charged by the method disclosed in Non-Patent Document 1 is to be peeled from the base material, there is a problem that peeling discharge occurs due to the sheet being strongly charged to positive or negative unipolarity. there were. Such strong charging of the sheet or charging due to the peeling discharge has caused secondary problems such as the peeled sheet sticking to another object or attracting dust. Therefore, after the sheet is once charged on the first temporary adhesion destination base material by the method disclosed in Non-Patent Document 1, the sheet is peeled off from the first temporary adhesion destination base material, and the first temporary adhesion is performed. Even if it is going to be bonded to a second temporary bonding destination base material different from the previous base material, due to problems such as sticking to an unintended part of the sheet or a decrease in adhesion due to adhesion of dust, the second temporary bonding It has been difficult to sufficiently adhere the sheet to the previous substrate. In other words, it is practically difficult to replace something once pasted with another one.

  On the other hand, as a sheet charging device, charging devices 2 and 3 having configurations shown in FIGS. 9 and 10 are conventionally known.

FIG. 9 shows the charging device 2 that irradiates the ions 301 generated by the ion generating electrode 2a from one side (first surface 100) side of the sheet S in a state where the sheet S floats in the air. The first surface 100 of the sheet is charged to the charge density σ ₁ [unit: C / m ² ] by the irradiated ions 301 (since the second surface 200 is not irradiated with ions, the second surface 200 200 and charge density sigma _{2 =} 0) of the sheet potential V _{a [unit:} V], the sheet and ground (earth is in a remote position, the electrostatic capacitance C _g between the not shown) [ By unit: F / m ² ], V _a = σ ₁ / C _g . Capacitance C _g between the seat and the ground, since as the distance between the sheet S and the earth is large becomes small, when in the state in which the seat S is floating in the air as shown in FIG. 9, the values of C _g Is small. That is, when the charge amount of the sheet S (charge density) sigma ₁ is slightly larger, the potential V _a of the sheet S is greatly increased. Although it depends on the distance to the ground, the capacitance between the sheet S and the ground in a state where the sheet S is floated in the air is about 10 to 100 pF. That is, when the sheet S is to be charged in a state where the sheet S is floated in the air, the potential becomes 10 kV to 100 kV only by charging the sheet S by about 1 μC / m ² . When the potential of the sheet S becomes high in this way, ions generated in the vicinity of the ion generating electrode 2a are subjected to a repulsive force due to Coulomb force and cannot reach the sheet. That is, it is difficult to charge the sheet to about 1 μC / m ² or more in the configuration of FIG. 9 even if ion irradiation is continued for a considerably long time.

On the other hand, the charging device 3 shown in FIG. 10 irradiates ions 301 from the first surface 100 side of the sheet S in a state where the second surface 200 of the sheet S is in contact with the ground conductor 3c. . At this time, the capacitance to the first surface 100 of the sheet, an electrostatic capacitance C _s between the ground conductor 3c, a large value because the sheet thickness is thin. Accordingly, the increase in the sheet S potential accompanying the increase in the charge density σ ₁ of the first surface 100 is gradual. The electrostatic capacity C _s [unit: C / m ² ] can be approximated by the electrostatic capacity of a parallel plate having a sheet thickness d _s [unit: m]. When the relative dielectric constant of the sheet S is ε _s , C _s = the ε ₀ ε _s / _{d s} (where, epsilon ₀ is the vacuum dielectric constant ^{.8.854 × 10 -12 F / m)} . Accordingly, unlike the charging device 2 shown in FIG. 9, a large amount of ions 301 can be irradiated onto the first surface 100 of the sheet S.

However, in the charging device 3 shown in FIG. 10, when the charge amount (charge density σ ₁ ) of the first surface 100 of the sheet S is about 30 μC / m ² or more, when the sheet S is peeled from the ground conductor 3c, The potential of the sheet S rises abruptly, and a peeling discharge 3d is generated between the sheet S (the second surface 200) and the ground conductor 3c. This is because the electric field strength between the sheet S (the second surface 200) and the ground conductor S exceeds 30 kV / cm, which is the breakdown electric field strength of air, at the time of peeling.

  The movement of electric charge due to the discharge is local on the electrically insulating sheet, and the second surface is locally charged with a polarity opposite to that of the first surface, but at any position in the in-plane direction of the sheet. The charge on both sides cannot be balanced.

If the charge amount of the first surface 100 of the sheet S is set to 30 μC / m ² or less, it is possible in principle to suppress the peeling discharge 3d. However, unlike the charging device 2 shown in FIG. On the contrary, in the charging device 3 shown, the electrostatic capacity is too large, so that the amount of charge changes greatly due to slight fluctuations in the applied voltage and ion irradiation time, and it is difficult to control.

For example, in the charging device of FIG. 10, the applied voltage, ion irradiation time, etc. are adjusted so that the charge amount of the first surface 100 of the sheet S is 30 μC / m ² or less, and the peeling discharge from the ground conductor 3c. Even if 3d is suppressed, electric discharge often occurs during handling of the sheet, for example, during winding. This is because at the time of winding, charge is superimposed on each sheet layer on the wound sheet roll, and the potential of the sheet roll is increased.

  On the other hand, in Patent Document 1, two sheets of reverse polarity DC or AC voltage are applied across one sheet S shown in FIG. Is disclosed (FIG. 11 shows an example in which an AC voltage is applied).

  Although not disclosed in Patent Document 1, according to the knowledge of the inventors of the present application, if the static eliminator 4 shown in Patent Document 1 is used, as will be described later, depending on conditions, each surface of one sheet Is charged to the polarity of the irradiated ions, and the sum of the charge densities on both surfaces at the same position in the in-plane direction of the sheet (hereinafter referred to as the apparent charge density) can be made substantially zero. . In other words, the positive and negative charges on both sides of the sheet are balanced, and if the distance from the ground point to the sheet thickness is a few times larger than the sheet thickness, the sheet is apparently charged on both the front and back sides. Looks like no. This state is hereinafter referred to as apparent non-charging.

However, Patent Document 1 discloses a sheet static eliminator 4, which is a technique for the purpose of producing an apparently uncharged sheet. Can not. Accordingly, in Patent Document 1, no study has been made on optimizing the charge amount of a sheet for the purpose of sticking to a temporary adhesion destination base material.
JP 2004-39421 A Electrostatic charging device CHARGEMASTER (R) catalog made by Simco Japan Toki et al., Electrostatic Phenomenon due to Bipolar Charging on Both Sides of the Film, Electrical Engineering A, Vol. 112, No. 8, The Institute of Electrical Engineers of Japan, August 1992, pp. 735-740 Electrostatic Handbook, Electrostatic Society, Ohmsha, 1998, p. 1155

  The object of the present invention is to solve the above-mentioned problems of the prior art described above, and to provide a temporary bonding method for a sheet that can be temporarily bonded to a substrate having a wide range of materials and shapes without remaining adhesive or fouling of the substrate. Is to provide. Another object of the present invention is to provide a charging method and a manufacturing method for manufacturing the temporarily bondable sheet.

In order to achieve the above object, according to the present invention, in at least a part of the in-plane direction of the sheet, the charge density of the first surface and the charge density of the second surface are each in the longitudinal direction of the sheet. to smoothly and periodically changes, and the amplitude of the change in the charge density, respectively, 6μC / m ² or more 1000μC / m ² or less, and, in at least a portion of the plane direction of the sheet There is provided a temporary adhesive sheet configured to include a charging sheet in which charging polarities of the first surface and the second surface are opposite to each other.

According to a preferred embodiment of the present invention, the period of change between the charge density of the first surface and the charge density of the second surface of the charging sheet is 10 mm or more and 100 mm or less, respectively. A temporary adhesive sheet is provided.

According to a preferred embodiment of the present invention, in each part on the charging sheet, the sum of the charge density of the first surface and the charge density of the second surface at the same position in the in-plane direction is − A temporary adhesive sheet is provided, which is ² μC / m ² or more and ² μC / m ² or less.

According to a preferred embodiment of the present invention, there is provided a temporary adhesive sheet characterized in that the charging sheet is a laminate of a plurality of sub-sheets.

  According to another aspect of the present invention, the first surface of the charging sheet is brought into contact with the temporary adhesion destination base material, and in this state, the second surface of the charging sheet is neutralized, thereby There is provided a method for temporarily adhering a sheet, characterized by temporarily adhering a charged sheet to the temporary adhering substrate.

  According to another aspect of the present invention, the first surface of the charging sheet having the sub-sheet is brought into contact with the temporary adhesion destination base material, and in this state, the charging sheet among the plurality of sub-sheets. The sub-sheet containing the second surface of the charging sheet is peeled off from the sub-sheet containing the first surface of the charging sheet, and the sub-sheet remaining without being peeled is used as the temporary adhering destination base material. A temporary bonding method for a sheet, characterized by temporary bonding.

  Moreover, according to the preferable form of this invention, the temporary attachment method of the sheet | seat characterized by using what the surface or the surface vicinity has electroconductivity as a temporary attachment destination base material is provided.

  Moreover, according to another form of this invention, the base material with a temporarily bonded sheet | seat characterized by the sheet | seat being temporarily bonded to the surface of the temporary bonding destination base material with the said temporary bonding method of a sheet | seat is provided.

  A typical sheet to which the present invention is applied is an electrically insulating sheet such as a plastic film, a fabric, and paper. There are two types of sheets: a long sheet that is usually handled in a rolled state, and a sheet that is usually handled in a state where a large number of sheets are stacked. Examples of the plastic film include polyethylene terephthalate film, polyethylene naphthalate film, polypropylene film, polystyrene film, polycarbonate film, polyimide film, polyphenylene sulfide film, nylon film, aramid film, and polyethylene film. In general, a plastic film has higher electrical insulation than a sheet made of other materials. The charging treatment technique provided by the present invention is suitably used for charging such a plastic film having high electrical insulation.

  In the present invention, the “sheet movement path” refers to a space through which a sheet passes for charging.

  In the present invention, “the normal direction of the sheet” means that the sheet moving along the moving path is not affected by external force such as gravity, and is regarded as a flat surface without sagging in the width direction. When there is a variation in the position of the sheet in the normal direction of the accompanying sheet, the normal direction of the plane (hereinafter referred to as a virtual average plane) when the sheet is assumed to be in the position averaged over time.

In the present invention, the “normal-direction inter-electrode distance d _i ” of the i-th charging unit refers to the tip of the first ion generation electrode 1d-i of the i-th charging unit from the most upstream in the sheet moving direction. This is the distance in the normal direction of the electrically insulating sheet between the second ion generating electrode 1f-i and the tip.

In the present invention, the i-th charging unit center position t _i i-th of the first ion generation electrode 1d-i of the distal end and the second ion generation of the charging unit from the most upstream in the moving direction of the sheet and the charging unit This is the position in the sheet moving direction of the midpoint 1x-i of the line segment connecting the tip of the electrode 1f-i.

In the present invention, the position of the sheet in the moving direction is the first charging unit center position t ₁ as a reference position (t ₁ = 0) and the sheet moving direction is positive unless otherwise specified.

  In the present invention, the charging unit center interval is an interval in the sheet moving direction of the charging unit center positions of the kth and k + 1th charging units from the most upstream in the sheet moving direction.

  In the present invention, the “rear surface equilibrium potential” of the first surface of the electrically insulating sheet means that the ground conductor is brought into close contact with the second surface, and charges are induced in the ground conductor, whereby the second surface In a state where the potential is substantially zero, the measurement probe of the surface potentiometer is sufficiently close to the first surface so that the distance from the first surface is about 0.5 to 2 mm And the potential of the first surface to be measured. As a measurement probe of the surface electrometer, a minute probe having a measurement opening diameter of 2 mm or less is used. Examples of such probes include a Monroe probe, 1017 (opening diameter: 1.75 mm), and 1017EH (opening diameter: 0.5 mm).

  In the present invention, the close contact of the back surface (second surface) of the electrical insulating sheet to the ground conductor means that the two sheets are in close contact with each other until there is no clear air layer between the interface between the insulating sheet and the metal roll. It means to make it. This state is a state in which the thickness of the air layer remaining between them is 20% or less of the sheet thickness and 10 μm or less.

  The distribution state of the back surface equilibrium potential on the first surface is determined by positioning the surface potential meter probe or the sheet with the ground conductor in close contact with the back surface (second surface) at the position of the XY stage or the like. Using the adjustable moving means, the back surface equilibrium potential is sequentially measured while moving at a low speed (about 5 mm / second), and the obtained data is obtained by mapping one-dimensionally or two-dimensionally. The back surface equilibrium potential of the second surface is measured in the same manner.

In the present invention, in each part of the film, the sum of the charge density of the first surface and the charge density of the second surface at the same position in the in-plane direction, that is, the apparent charge density is −2 μC / m. ² or more and +2 μC / m ² or less means that when a 10 cm × 10 cm film is cut out, the charge density distribution at the same position on the first surface 100 and the second surface 200 is perpendicular to the moving direction of the film. A value obtained by measuring continuously in the moving direction of the film at 20 or more positions in a certain direction and taking the sum at the corresponding position on the film is included in this range.

    According to the present invention, as will be described below, there is no residual adhesive or fouling of the base material, and it is possible to temporarily bond to a wide variety of materials and shapes of base materials. Further, a large-scale bonding apparatus is not required at the time of temporary bonding, and temporary bonding can be easily performed on any surface of the sheet. In addition, temporary adhesion is possible for a long time without lowering the adhesion.

  Hereinafter, an example of the best embodiment of the present invention will be described with reference to the drawings, taking as an example a case where a plastic film (hereinafter simply referred to as a film) is used as an electrically insulating sheet. However, the present invention is not limited to these examples.

  FIG. 1A is a schematic cross-sectional view of an electrical insulating sheet charging apparatus 1 suitable for producing the charging sheet of the present invention.

  In FIG. 1A, the charging apparatus 1 has a guide roll 1a on the left side and a guide roll 1b on the right side. A traveling film S is stretched between the guide roll 1a and the guide roll 1b. The guide roll 1a and the guide roll 1b are rotated clockwise by a motor (not shown). The film S continuously moves in the direction of the arrow 1ab at a speed u [unit: mm / second] by the rotation of the guide rolls 1a and 1b. Between the guide roll 1a and the guide roll 1b, two charging units CU1 and CU2 are provided at intervals in the moving direction of the film S (direction of the arrow 1ab). FIG. 1B shows the configuration of each charging unit, and FIG. 1C shows the arrangement of the charging units. As shown in FIG. 1B, in each charging unit, the first ion generation electrodes 1d-1 and 1d-2 arranged on the first surface 100 side of the film and spaced from the first surface 100 are the first ones. A second ion generating electrode 1f-1, which is connected to one AC power source 1c-1, 1c-2, and is disposed on the second surface 200 side of the film at a distance from the second surface 200, 1f-2 is connected to second AC power supplies 1e-1 and 1e-2 having a polarity opposite to that of the first AC power supplies 1c-1 and 1c-2.

The distance between the normal direction electrodes in the first charging unit CU1 is d ₁ [unit: mm], and the distance between the normal direction electrodes in the second charging unit CU2 is d ₂ [unit: mm]. As shown in FIG. C, the first charging unit and the second charging unit are arranged in parallel in the moving direction of the film at a charging unit center interval p [unit: mm].

  First, consider a point in time when a certain part on the film passes between the first ion generation electrode 1d-1 and the second ion generation electrode 1f-1. At this time, if a positive voltage is applied to the first ion generation electrode 1d-1 and a negative voltage is applied to the second ion generation electrode 1f-1, as shown in FIG. The positive ions 301 and the negative ions 302 are forcibly irradiated and adhered to the second surface 200 of the film S simultaneously.

The forced irradiation of ions on both surfaces of the film S is performed by the first and second ion generation electrodes 1d-i, 1f of the i-th charging unit CUi (i = 1, 2 in the example of the present embodiment). The effective value V _i [unit: V] of the potential difference of the applied voltage to −i, the distance d _{i in} the normal direction of the sheet at the tip of the first and second ion generation electrodes 1d-i, 1f- _i [unit: mm] occurs when the following equation is satisfied.

180 ≦ V _i / d _i ≦ 1060 and V _i / d _i > 0.17 × d _i xf
The above formula is the average electric field strength (V _i between the first ion generation electrode 1d-i and the ion generation electrode tip where the amount of positive and negative ions 301, 302 generated in the second ion generation electrode 1f-i increases. / D _i ). According to the study by the inventors, when the second ion generating electrode 1f-i is made to face the first ion generating electrode 1d-i under the condition that 180 ≦ V _i / d _i , the second ions made to face each other Since the reverse polarity voltage is applied to the generation electrode 1f-i, the electric field strength near the tip of the first ion generation electrode 1d-i is increased, and the discharge current generated by the first ion generation electrode 1d-i may increase. It has been confirmed (can be confirmed by a change in the output current of the first AC power supply 1c-i). That is, the ion can be radiated in a concentrated manner between the first and second ion generation electrodes 1d-i and 1f-i. Further, the upper limit (V _i / d _i ≦ 1060) of the average electric field strength between the tips of the ion generation electrodes is generally determined by the voltage of the spark discharge transition.

V _i / d _i > 0.17 × d _i xf is the relationship between the average electric field strength (V _i / d _i ) between the tips of the ion generation electrodes, the distance d _i between the normal direction electrodes, and the frequency f of the applied voltage. It is shown. When the applied voltage frequency f or the normal direction inter-electrode distance _{d i} is increased, the first ion generation electrode 1d-i, and positive and negative ions 301 and 302 generated in the second ion-generating electrode 1f-i is, the film This is because the polarity of the voltage applied to each of the ion generation electrodes 1d-i and 1f-i is reversed sooner before reaching the position, and sufficient ion irradiation (by charging the film) cannot be performed.

  As described above, when ions having opposite polarities are irradiated from both sides with the film interposed therebetween, the charge amount of the first surface 100 and the second surface 200 at each position in the in-plane direction of the film irradiated with ions. The amount of charge is opposite to the polarity and is almost equal. This is due to the following function.

  If the amount of positive ions 301 generated by the first ion generation electrode 1d-1 and the amount of negative ions 302 generated by the second ion generation electrode 1f-1, the individual difference of the ion generation electrodes, the ion generation Consider the case where there are variations due to differences in capabilities. Suppose that the amount of negative ions 302 generated by the second ion generation electrode 1f-1 is larger than the amount of positive ions 301 generated by the first ion generation electrode 1d-1. The second surface 200 of the film S is irradiated with a large amount of negative ions 302, and once the negative ions 302 are excessively attached to the film S, the second ion is applied by the Coulomb force 700 by the negative ions 302 excessively attached. Adhesion of negative ions 302 to the surface 200 is suppressed, and adhesion of positive ions 301 to the first surface 100 is promoted.

  This provides an automatic function to eliminate excessive negative ion 302 adhesion. Thereby, excessive adhesion of the negative ions 302 is quickly eliminated. The same applies when the positive ions 301 are excessively adhered, and the positive and negative charge densities of the first surface 100 and the second surface 200 of the film S are equal and have opposite polarities.

  Therefore, the apparent charge density is zero at each position in the in-plane direction of the film S. That is, the film is in an apparent uncharged state. According to the knowledge of the present inventors, the difference in ion generation capability and ion irradiation capability between the first ion generation electrode 1d-1 and the second ion generation electrode 1f-1 is usually 50% or more and 200% or less. If so, the film S is kept in an apparent uncharged state.

  In addition, a large amount of electric charge can be supplied to each surface due to such an apparent non-charged state. This is due to the following reason.

  When the apparent uncharged film is in the air, the potential from its grounded ground is nearly zero. This is because the thickness of the film is sufficiently small with respect to the distance from the ground, so that the potential from the ground point in the sum is not distinguished without distinguishing the charging of the first surface 100 and the charging of the second surface 200 of the film. It is because it becomes. Note that the potential measured in this way is called an imaginary potential.

  Therefore, if the apparent uncharged state is maintained, the imaginary potential of the film is maintained at zero.

Therefore, in the prior art, unlike the case of the charging device 2 that charges only the first surface 100 of the film shown in FIG. 9, the positive and negative ions 301 and 302 are transferred to the first surface and the second surface 100 of the film, respectively. 200, and it becomes possible to charge each side of the film to a desired charge level of several μC / m ² or more.

Further, unlike the case of the charging device 3 that charges only the first surface 100 of the film shown in FIG. 10 in the prior art, the ground conductive member even if the charge density on each surface is 30 μC / m ² or more. There is no discharge during contact with and peeling from the film, winding of the film onto a film roll, and the like. This is due to the following actions.

Suppose that the first surface 100 of the film S charged by the charging device 1 of FIG. 1 is in close contact with the ground conductive member. At this time, the charge on the first surface 100 of the film S is canceled by the reverse polarity charge induced on the surface of the ground conductive member, and the potential on the first surface (contact surface) of the film becomes zero. Therefore, in this state, the potential V _f2 [unit: V] measured from the second surface side of the film is σ ₂ [unit: C / m ² ] as the charge density of the _second surface, Assuming that the electric capacity is C _f [unit: F / m ² ], V _f2 = σ ₂ / C _f and does not become zero. Here, C _f is the film thickness d _f [unit: m], relative dielectric constant ε _f , vacuum dielectric constant ε ₀ = 8.854 × 10 ⁻¹² F / m, and C _f = ε ₀ ε _f It can be approximated by / _{d f.} The potential V _f2 measured on the ground conductive member in this way is referred to as the back surface equilibrium potential of the second surface of the film.

  As soon as the film is peeled from the ground conductive member, the influence of the charge on the first surface appears. When the distance between the film and the ground conductive member is only a few times the film thickness, the potential of the film becomes almost zero due to the balance between the charge on the first surface 100 and the charge on the second surface 200. Become. That is, when the film is charged by the charging method of the present invention shown in FIG. 1, the potential of the film is non-zero only on and around the ground conductive member. Before the electric field strength between the members becomes a strong electric field strength leading to discharge, the electric potential of the film is lowered, so that no discharge occurs.

  Therefore, when a film that is apparently uncharged and has opposite polarities on both sides, which is made by the charging apparatus 1 of FIG. 1, is used as a temporary adhesive film, it is used as follows. Hereinafter, the first surface 100 will be described as an adhesion surface to the temporary bonding destination base material B, and the second surface 200 will be described as the opposite surface. Here, the temporary bonding destination base material B will be described as a grounded conductor C.

  First, the first surface 100 of the film S is brought into contact with the portion of the temporary bonding destination base material B to be temporarily bonded. The state of charging at this point is shown in FIG. As shown in FIG. 3, the electric lines of force 500 are almost terminated between the charges 101 and 102 on the first surface 100 of the film S and the charges 201 and 202 on the second surface 200, so In this state, the adhesion force is hardly applied to the base material B.

  Next, the second surface 200 is neutralized while keeping the first surface of the film in contact with the temporary adhesion destination base material B. The method of neutralizing the second surface 200 can be performed by irradiating ions with a static eliminator, wiping with a small amount of alcohol, or wetting with a small amount of water. In particular, it is most convenient to wipe with a small amount of water or a polar solvent such as alcohol. When this static elimination is completed, that is, after ions from the static eliminator are irradiated or water or alcohol is dried, the charged state of the film S is as shown in FIG. That is, when the charges 201 and 202 on the second surface 200 of the film S shown in FIG. 3 are all or partially neutralized, the charges 101 and 102 on the first surface 100 of the film S as shown in FIG. Becomes excessive. The induced charges 402 and 401 appear on the surface of the conductor C, which is the temporary bonding destination base material B, with respect to the charges 101 and 102 on the first surface 100 that have become excessive, and the charges 101 and 102 on the first surface 100 The electric lines of force terminate between them (in FIG. 4, since the charges 101 and 102 of the first surface 100 and the induced charges 402 and 401 are very close to each other, not shown), the adhesion force (Coulomb force) works. The film S is fixed to the temporary bonding destination base material B.

  Here, when removing the charges 201 and 202 on the second surface 200, it is important that the first surface 100 of the film S is in contact with the temporary bonding destination base material B in any method. It is. This is because, when the first surface 100 of the film S is separated from the temporary bonding destination base material B, the charge of the first surface 100 and the charge of the second surface 200 (the apparent charge) ) On the other hand, that is, the static elimination action works (that is, the static elimination action does not work on a film having an apparent charge density of zero).

  However, it is not necessary to completely remove the charges 201 and 202 on the second surface 200. This is because the charges 102 and 101 of the first surface 100 that are excessive due to the charge removal of the charges 201 and 202 of the second surface 200 may be sufficient for the adhesion between the film S and the temporary bonding destination base material B. .

Further, in FIG. 4, the case where the temporary bonding destination base material B is a grounded conductor C is taken as an example, but the temporary bonding destination base material B is a conductor C coated with a semiconductor or a dielectric, non-grounded. As long as the conductor C or the like has an induction or polarization charge on the contact surface with the film (the surface of the temporary adhesion destination base material B), the charge on the first surface 100 of the film and the temporary adhesion destination An adhesion force works between the induction of the surface of the substrate B or the polarization charge. In addition, when using a charged sheet (film) formed by laminating a plurality of sub-sheets, one outer sub-sheet (referred to as the first sub-sheet) is used as a temporary bonding destination base material for conductors and insulators. Also, the charge on one side of the charging sheet (film) can be removed by separating the opposite outer sub-sheet (second sub-sheet) in a state of being in close contact with each other. Also by this, it is possible to exert an adhesion force between the excessive charge on the outer surface (adhesion surface) of the first sub-sheet and the induction or polarization charge of the temporary adhesion destination base material. In this case, when the second sub-sheet is peeled from the first sub-sheet, the first sub-sheet (the first surface of the charging sheet) is not contacted with the temporary adhesion destination base material. It is possible to remove the charge on the second sub-sheet (charge on the second surface of the charged sheet), but in this case, the charge on the first sub-sheet (first surface of the charged sheet) and the second This is not preferable because the electric field generated in the peeled portion increases due to the charging of the sub-sheet (second surface of the charging sheet), and discharge often occurs. Therefore, the first sub-sheet (the first surface of the charged sheet) is in contact with the temporary adhesion destination base material even when the charge is removed on one side of the charged sheet by separating the second sub-sheet. It is preferable to carry out with.
As described above, the apparently uncharged film having the opposite polarity on both sides, which is produced by the charging device of FIG. 1, has the following excellent characteristics as a temporary adhesive film.

  In an apparently uncharged film, the electric lines of force terminate between the charges on both sides when placed in the air, that is, the electric field due to the charges on both sides is closed inside the film (thickness direction), so the outside It is difficult to exert close contact with the object. For this reason, before performing temporary adhesion, it does not come into contact with other objects, and it is not necessary to protect the pressure-sensitive adhesive layer with a release sheet or the like.

  When such a film is temporarily bonded, at the time of positioning, as shown in FIG. 3, the electric field due to the charges 101, 102, 201, 202 on the first surface 100 and the second surface 200 of the sheet is generated. Since it is still almost closed inside the film (the electric lines of force 500 are concentrated inside the film), unnecessary adhesion force does not act on the temporary bonding destination substrate. Therefore, positioning on the temporary bonding destination base material is easy. Moreover, since the charge of the contact surface can be expressed by wiping with water or alcohol after positioning the film, the shape of the temporary adhesion destination base material is not particularly limited. In addition, since a pre-charged film is used, no large-scale equipment (such as charging by sandwiching the temporary bonding destination base material and the film) is required in the attaching process.

  In addition, since the Coulomb force (adhesion force) works between the charges on the adhesion surface of both the film and the temporary adhering substrate, unlike the charging by the conventional charging method shown in FIG. It ’s hard. That is, as shown in FIG. 7, in the method of charging by sandwiching the base material and the film, when the thickness of the base material and the film is increased, it is easy to be affected by an external conductor or a charged body, and the adhesion force is reduced. On the other hand, when the film according to the present invention is used as a temporary adhesive film, it is hardly affected by an external conductor or a charged body, and can be applied to a wide range of thicknesses of substrates and films.

When the charge on the second surface 200 is completely removed, the back surface equilibrium potential V _f2 (on the second surface) of the film is theoretically zero in the ideal state. Therefore, the film S after bonding does not attract ions or dust in the air and does not impair the aesthetic appearance (in the method disclosed in the prior art shown in FIG. 8, the back surface equilibrium potential of the film S after bonding is In principle, it does not become zero and attracts dust and the like in the air. However, in the film S according to the present invention, this is not the case when the charges 201 and 202 on the second surface 200 are completely removed.

On the other hand, when the charges 201 and 202 of the second surface 200 are not completely removed, the back surface equilibrium potential V _f2 (of the second surface 200) of the film S is non-zero. Accordingly, ions in the air are attracted and the back surface equilibrium potential V _f2 decreases with time, that is, the charges 201 and 202 on the second surface 200 may be neutralized. However, the charge removal of the charges 201 and 202 on the second surface 200 causes the unbalanced charge on the first surface 100 to become excessive. That is, the adhesion force increases with time (in the method disclosed in the prior art shown in FIG. 8, since the attachment is performed by the charge on the surface exposed to ions in the air, the charge on this surface is reduced. When the static electricity is removed over time, the adhesive force decreases, but this is not the case with the film S according to the present invention.

  Although the case where the first surface 100 of the film S is brought into close contact with the temporary bonding destination base material B to perform temporary bonding has been described above, the second surface 200 may be used for temporary bonding in the same manner. Usually there is no problem. That is, it can be used for temporary bonding without selecting the surface of one film S.

  As the charged state of the film for such temporary bonding, from the viewpoint of adhesive strength, each surface may be charged with positive or negative single polarity (each). As shown in FIG. 5, in view of ease of handling when peeling off after temporary adhesion, handling properties when handling a film as a film roll, etc. Is more preferable. FIG. 5 is a schematic diagram showing the charged state of each surface of the film, and the distribution of the back surface equilibrium potential of each surface is as shown in FIG.

  First, consider the effect of residual charge remaining on the film when the film is temporarily bonded and then peeled off. Since the charges 201 and 202 on the second surface 200 are removed at the time of temporary adhesion, if the film S is peeled after temporary adhesion, the charge on the first surface 100 is equal to the amount of charge balanced with the removed charges. Is excessive. When each surface is charged positively or negatively with a single polarity, the potential of the film S after peeling greatly increases to the polarity of the excess charge, causing discharge, It may cause sticking to an object, which is not preferable. When each surface of the film S is charged while periodically changing its polarity smoothly, the potential of the film S is low (viewed from a distance), causing electric discharge or sticking the film S to other objects. It is preferable that it does not stick.

  Moreover, when supplying this film S as a film roll body, when each surface of the film S is each charged to positive or negative monopolarity, the problem that the electric potential of a film roll surface becomes high, and it accompanies it There are problems such as peeling discharge during feeding. This is because an electric double layer having a large gap as shown in Non-Patent Document 2 is produced when the film S, which is charged with positive or negative single polarity on each surface, is wound up on a film roll body. .

As shown in FIG. 12, the electric double layer in the film roll body is as if the positive electrostatic charge 201 on the second surface (inner surface) 200 of the first layer sheet S ₁ and the outermost layer sheet S. That is, it appears that there is only a negative electrostatic charge 102 on the first surface (outer surface) 100 of _f . This positive charges of the first surface (outer surface) 100 negative charges of 102 and the second side of the sheet _{S 2} of the second layer (inner surface) 200 of the sheet _{S 1} of the first layer 201 DOO are balanced, (is j, a positive integer) the j layer below th sheet _S first surface (outer surface) 100 negative charges 102 of the (j + 1) th-layer sheet _{S j + 1} of the second of the _j This occurs because the positive electrostatic charge 201 on the face (inner face) 200 balances and it appears that no charge is present. In this state, an electric double layer having a large apparent gap is formed on the film roll body, and the electric potential on the surface of the film roll body is increased, and problems such as discharge are likely to occur. Therefore, this state is not preferable.
On the other hand, as shown in FIG. 13, when each surface of the film is wound up on a film roll body as shown in FIG. in some parts of the film roll, and the negative charges 102 of the first surface (outer surface) 100 of the j th layer of the sheet _{S j,} (j + 1) th layer of the sheet _{S j + 1} of the second surface (inner surface) 200 Negative electrostatic charge on the first surface (outer surface) 100 of the m-th layer sheet S _m even if there is a portion where the positive electrostatic charge 201 balances and there is no apparent charge. There always occurs a situation in which the portion 102 and the negative electrostatic charge 202 of the second surface (inner surface) 200 of the (m + 1) th layer sheet S _{m + 1} have the same polarity. Note that m is a positive integer different from j. For this reason, positive and negative charges are also present in the inner layer portion of the film roll body evenly and appropriately, the electric lines of force are closed between them, and the charge of the outermost layer sheet is also equal to the charge of the inner layer sheet. In addition, the electric field lines close to each other between the electric charge of the sheet of the first layer and the electric charge of the sheet of the outer layer. As a result, even if the film S is wound up as a roll body, an electric double layer having a large gap does not occur, and the potential of the roll body does not become excessive.

  If the period of change in the polarity of the charge on each side of the film is too large, as with each side of the film being charged to a single positive or negative polarity, the problem of discharge at the time of peeling after temporary bonding, Problems such as sticking of the film to other objects at the time of peeling after temporary bonding are likely to occur. On the other hand, if this period is too short, or if the polarity of the charge on each side of the film is not smooth and changes rapidly, the creeping direction of the film (positive and negative charge) when peeling the film There is a risk of discharge between the two. Therefore, it is preferable that the period in which charging (charge density) of each surface of the film changes is about 10 to 100 mm. Examples of the smooth change in the charging polarity include a case where the charge density on each surface of the film changes in a sine wave shape, a triangular wave shape, or a trapezoidal wave shape.

As described above, when a film made by the charging device 1 of FIG. 1 that is apparently uncharged and has opposite polarities on both sides is used as a temporary bonding film, a preferable charge amount is obtained as follows. It is done.
(1) In the case where the film is brought into close contact with the temporary adhesion destination base material that is a conductor When the film is brought into close contact with the temporary adhesion destination base material B that is a conductor C as shown in FIG. The distance between 102 and the induced charges 402 and 401 on the surface of the temporary bonding destination base material B is so small as to be negligible as compared with the thickness of the film. Therefore, the adhesion force between the film and the temporary bonding destination base material B is f = σ ₁ ² / 2ε ₀ [unit: N] according to the charge density σ ₁ [unit: C / m ² ] of the first surface 100. / M ² ]. On the other hand, although the density of a film changes with kinds of film, it is about 1 g / cm < ³ >. For example, in a film having a thickness of 100 μm, a force of about 0.01 gf / cm ² is applied due to gravity. If a force corresponding to gravity is required to bring the film S into close contact with the temporary bonding destination base material B by electrostatic force, this can be realized by charging at σ = 4.1 μC / m ² .

If charging of the surfaces of the film S is smoothly polarity change, as long mean square of each surface charge density is an 4.1μC / m ^2, achieves this in a sinusoidal charge amplitude about 6μC / m ² it can.
(2) In the case where the film is brought into intimate contact with the temporary adhering base material which is a dielectric having a conductive layer therein When the film S is brought into intimate contact with the temporary adhesion base material B which is a dielectric having a conductive layer D therein, The distance between the charges 101 and 102 on one surface 100 and the induced charges 402 and 401 on the surface of the conductive layer D is the thickness d _C [unit: m] of the dielectric layer therebetween. The adhesion force between the film S and the temporary bonding destination base material B is influenced by the external electric field of the electric charges 201 and 202 of the second surface 200, and thus it is difficult to obtain it generally. Therefore, in general, as a condition for the smallest adhesion force, the adhesion force in a state where the second surface 200 is grounded (in contact with the conductor C) as shown in FIG. 14 is obtained.

The first charge density of the surface 100 sigma ₁ [Unit: C ^{/ m} 2], the ratio of the film thickness _d f [m], the relative dielectric constant of the film epsilon _f, the dielectric layer of temporary adhesive base B When the dielectric constant is ε _c , the adhesion force is determined by f = σ ₁ ² / {2ε ₀ (ε _c + ε _f d _C / d _f ) ² } [unit: N / m ² ]. That is, 1 / (ε _c + ε _f d _c / d _f ) ² times that in the case of direct contact with the conductor C. In the case of d _f >> d _C , that is, when the thickness d _C of the dielectric layer is smaller than the film thickness d _f , the adhesion force is about 1 / ε _c ² in the case of direct adhesion to the conductor. Although it depends on the dielectric material, if the relative dielectric constant ε _c is about several to several tens, sufficient adhesion can be secured by increasing the charge density several to several tens.

On the other hand, in the case of d _f << d _C , if the relative dielectric constant ε _{c of the} dielectric layer is about the same as (below) the relative dielectric constant ε _f of the film, the adhesion force is (d _f / ε _f d _C ) becomes about ² times.
If the thickness _{d C} of the dielectric layer is set to 10 times the film thickness _{d f} (the film thickness of 100 [mu] m, thickness 1mm dielectric layer), when 3 the relative permittivity epsilon _f of the film, the charge density, When the amplitude changes to a sinusoidal shape with an amplitude of 200 μC / m ² , the adhesion force f is 0.013 gf / cm ² .

As described above, when a film having an amplitude of several to several hundreds μC / m ² and periodically changing the polarity periodically and having an apparent charge density of almost zero is manufactured, the film S is accelerated. While moving at u [mm / min], an alternating voltage may be applied to the ion generating electrodes 1d-1, 1f-1, 1d-2, 1f-2 of each charging unit as shown in FIG. The speed u needs to be determined appropriately. This is because ions are not concentrated and irradiated only on the center position of the charging unit (position in the sheet movement direction represented by 1x-1, 1x-2), but have a certain extent in the sheet movement direction. It is because it is irradiated. That is, when the velocity u is low, ions irradiated at a time passing through the charging unit center position and ions irradiated at a time before (after) the charging unit center position with respect to a certain position on the film This is because the polarity of the film is reversed, and the film cannot be sufficiently charged (if the ions of reverse polarity are irradiated, the amount is offset).

In general, when ions are irradiated with an ion generation electrode and a ground metal facing each other, the ions are distributed in a concentration range of about cos ⁵ θ within a range of about −60 ° <θ <+ 60 ° from the normal direction of the ground metal. Is known to be irradiated (see, for example, Non-Patent Document 3). As in the present invention, the electric fields in the case where the ion generation electrodes to which the reverse polarity voltage is applied are opposed to each other and the case where the ion generation electrodes are opposed to the ground metal are equivalent on the ion generation electrode side by the image method. is there. Therefore, even when the ion generating electrodes are opposed to each other, it can be considered that the ions are irradiated with a concentration distribution of about cos ⁵ θ in a range of about −60 ° <θ <+ 60 °.

Ions are cos ⁵ θ (provided that the film passes through half the normal-direction inter-electrode distance, the moving direction distance from the charging unit center position is x [unit: mm], and θ = arctan (2x / When the concentration distribution of the ion to be irradiated is calculated by convolution integration of cos ⁵ θ and sin (2πfx / u) when it is assumed that the irradiation is performed with the concentration distribution of d))). Changes in a sinusoidal shape with a period u / f [unit: mm] with respect to the sheet moving direction distance x. Therefore, when the maximum value of the convolution integral (the amplitude of the sinusoidal fluctuation) is examined for u, u = df / 2 is 2/3. This means that 1/3 of the negative ions were irradiated with 1/3 of the positive ion dose, and the charging by the positive ions was offset accordingly. At this time, the total irradiation ion amount was 1 + 1/3, which means that half of the total irradiation ion amount contributed to the charging of the film.

  That is, when the film is moved at a slow speed such that u ≦ df / 2, the negative ions generated at the time before and after the first surface on the film are irradiated with the largest number of positive ions. Due to the influence of irradiation, the position on the first surface of the film cannot be positively charged sufficiently. In order to contribute more than half of the ions irradiated to each position on the film to charge, it is important to use at a speed u where u> df / 2.

Thus, there is a lower limit to the film speed that can be used in order to charge the film strongly so that the polarity changes periodically and smoothly using one charging unit. On the other hand, when the film moving speed u is increased, the amount of ions irradiated from one charging unit per unit area of the film decreases in proportion to 1 / u. In order to charge each side of the film to a sufficient charge level (for example, a charge density of several tens to several hundreds μC / m ² ) at an appropriate speed, a plurality of charging units are used. What is necessary is just to arrange | position a charging unit so that the polarity of the ion irradiated to the 1st surface of a film from a charging unit may become the same polarity. In this case as well, in all the charging units, u> d with respect to the distance d _i between the radiation direction electrodes of each charging unit (where i represents the value in the i-th charging unit from the upstream in the sheet moving direction). _It is preferable to use at a speed satisfying if / 2.

For example, as shown in FIG. 1, when charging is performed in an apparatus having two charging units, the position on the film in which the first surface 100 is irradiated with positive ions 301 in the first charging unit CU1. Even in the second charging unit CU2, the first surface 100 may be irradiated with positive ions 301. Since the charging unit center interval is p [unit: mm], the first ion generating electrode 1d-1 of the first charging unit CU1 and the first ion generating electrode 1d-2 of the second charging unit CU2 are connected to each other. When an AC voltage of the same phase is applied, the film is applied at a speed u _m [unit: mm / second] where mu _m = pf (where m is a natural number and f is the frequency of the AC voltage [unit: Hz]). This can be achieved by moving it. Also the moving speed of the film is shifted about ± 100 mm / sec relative to u _m, the first charging unit CU1, the majority of positions on irradiated with positive ions 301 in the first surface 100 Film Even in the second charging unit CU2, there is no problem because the first surface 100 is irradiated with the positive ions 301.

  In the first charging unit CU1, the first surface 100 is irradiated with the negative ions 302 at most positions on the film where the first surface 100 is irradiated with the positive ions 301 in the second charging unit CU2. Then, each surface of the film cannot be sufficiently charged, which is not preferable. In more than 2/3 of the moving direction of the film, more than 3/4 of the irradiated ions have the same polarity (the reverse polarity ions are 1/4 or less. That is, the reverse polarity ions are determined from the irradiation amount of the same polarity ions. Even if the amount of irradiation is subtracted, more than 1/2 of all irradiated ions contributes to charging).

Even when three or more charging units CU1 to CUn (where n is the total number of charging units) are used, the charging unit center intervals are all constant values p ₀ [mm], and the first ion of each charging unit The voltages applied to the generation electrodes 1d-1 to 1d-n are substantially in phase (the voltages applied to the second ion generation electrodes 1f-1 to 1f-n of each charging unit are also substantially the same. In the case of (phase), if the sheet is moved at a moving speed u [mm / second] where the following X value indicating the degree of coincidence of the polarities of ions irradiated from each charging unit is greater than 0.5, At the position where the film is most strongly positively or negatively charged, more than half of the irradiated ions contribute to the charging, which is preferable.
X = | sin (nπfp ₀ / u) / {n × sin (πfp ₀ / u)} |
(Mu ≠ fp ₀ where m is a natural number)
= 1 (mu = fp ₀ )
Also, when 3 or more charging units are used and the center interval of each charging unit is not a constant value, or when 2 or more charging units are used and the phase of the voltage applied to the ion generating electrode of each charging unit is different Calculates the value of X indicating the degree of coincidence of the polarities of ions irradiated from each charging unit by the following formula, and moves the sheet at a moving speed u [mm / sec] at which the value is greater than 0.5. In this case, at the position where the film is most strongly positively or negatively charged, more than half of the irradiated ions contribute to the charging, which is preferable.

(However, the charging unit center position of the _i- th charging unit (where i is an integer from 1 to n) from the most upstream in the sheet moving direction is t _i [mm] (where the first charging unit The charging unit center position t ₁ is t ₁ = 0 and the sheet moving direction is positive), and the voltage applied to the first ion generating electrode is applied to the first ion generating electrode of the first charging unit. The phase with respect to the applied voltage is α _i [rad], and y _i = 2πf · t _i / u−α _i )
In particular, when the charging process is performed at a speed u where X> 0.75 in these two formulas of X, more than 75% of all irradiated ions contribute to the charging, which is particularly preferable.

    The result of charging the film using the above charging processing apparatus will be described. The effect of charging in Examples and Comparative Examples was evaluated by the following method.

The surface opposite to the evaluation surface of the film was brought into close contact with a metal roll made of a hard chrome plating roll having a diameter of 10 cm, and the potential was measured. A Monroe model 244 was used as the electrometer, and a Monroe probe 1017 having an opening diameter of 1.75 mm was used as the sensor. An electrometer was placed 2 mm above the film. The field of view at this position is in the range of about 6 mm in diameter from the Monroe catalog. The back surface equilibrium potential V _f [unit: V] was measured with an electrometer while rotating the metal roll at a low speed of about 1 m / min using a linear motor.

Based on this back surface equilibrium potential V _f [unit: V], the relational expression σ = C × V _f (where C is the capacitance per unit area [unit: F / m ² ]) is used to evaluate the film. The charge density σ of the surface was calculated. Since the film thickness is sufficiently smaller than the measurement field of view, the electrostatic capacity C per unit area is the parallel plate electrostatic capacity C = ε ₀ × ε _r / d _f (where _df is the thickness of the film) , Ε ₀ is approximated by a dielectric constant of 8.854 × 10 ⁻¹² F / m in vacuum, and ε _r is a relative dielectric constant of the film). The relative dielectric constant ε _r of polyethylene terephthalate was 3.

Further, regarding the sum of the charge density of the first surface and the charge density of the second surface at the same position in the in-plane direction, the film is cut into 10 cm × 10 cm, and the first surface 100 and the second surface The distribution of the charge density at the same position on the surface 200 was continuously measured in the film moving direction at 20 or more positions in the direction perpendicular to the film moving direction, and the sum at each position was obtained. .
[Example 1]
In the electrification apparatus shown in FIG. 1, a biaxially stretched polyethylene terephthalate film (Lumirror 75T10 manufactured by Toray Industries, Inc.) having a width of 300 mm and a thickness of 75 μm is used as the electrically insulating sheet S, and the film S at a speed of 90 m / min. Moved. It was confirmed that each surface of the film S was almost uncharged before the charging treatment.

  In all the charging units, the charging electrode 7 having a needle electrode array shown in FIG. 15 is used, and the needle electrode array 7a is used as the first and second ion generation electrodes 1d-1, 1d-2, 1f-1. Used as 1f-2. The interval z in the width direction of the needle was 12.7 mm. The charging electrode 7 was installed up and down with the film S interposed therebetween so as to be orthogonal to the moving direction of the film S and parallel to the surface of the film S, thereby forming a charging unit. In the upper and lower charging electrodes of the film S, the position of the needle tip in the sheet moving direction and the width direction are the same. The total number n of charging units was 2.

The tip of each needle electrode row 7a, that is, the tip of each ion generation electrode generation electrode 1d-1, 1d-2, 1f-1, 1f-2 of each charging unit CU1, CU2 is arranged linearly in the width direction. The deflection of the electrode with respect to the normal direction and the moving direction of the film was negligibly small. Further, as described above, since the static elimination units CU1 and CU2 are arranged so as to be orthogonal to the moving direction of the film S, the following values of d ₁ , d ₂ , p ₁ , θ ₁ , and θ ₂ have a clear width. It was judged that there was no direction distribution. These values are values measured at the widthwise ends of the charging electrode 7 and the charging units CU1 and CU2.

In each of the charging units CU1 and CU2, the normal direction inter-electrode distances d ₁ and d ₂ were both 25 mm, and the opening angles θ ₁ and θ ₂ were both π / 2 rad.

Charging unit center distance _{p 1} is a 25 mm, the width direction position of the needle tip in the two charging unit CU1, CU2 were the same. The first ion generation electrodes 1d-1 and 1d-2 of the two charging units CU1 and CU2 are in phase (the second ion generation electrodes 1f-1 and 1f-2 are also in phase), and the first ion generation electrode 1d -1 and 1d-2 are connected to a power source 1c (shared), and the second ion generation electrodes 1f-1 and 1f-2 are connected to a power source 1e (shared), an effective voltage of 4 kV and a frequency of 60 Hz. The input of the step-up transformer inside the power supply was switched so that the phases were reversed. The shield electrodes 1g-1, 1g-2, 1h-1, and 1h-2 were all grounded. The film S was allowed to pass through the approximate center between the first and second ion generation electrodes in each charging unit CU1, CU2.

Regarding the charge distribution of the film S subjected to the charge treatment, the charge densities of the first surface and the second surface were examined based on the above measurement method. The charge densities of the first surface and the second surface were sinusoidal charges with an amplitude of 60 ± 5 μC / m ² and a period of 25 ± 1 mm, respectively. The sum of the charge density of the first surface and the charge density of the second surface at the same position in the in-plane direction was in the range of −1.8 to +1.8 μC / m ² .
[Comparative Example 1]
Except for removing the charging electrode 7a (the second ion generation electrodes 1f-1 and 1f-2 of the first and second charging units in FIG. 1) installed under the film S (the film S, the first The distance between the ion generating electrodes 1d-1 and 1d-2 was about 12.5 mm in the same manner as in Example 1, and the film S was charged in the same manner as in Example 1. Regarding the charge distribution of the film S subjected to the charge treatment, the charge densities of the first surface and the second surface were examined based on the above measurement method. The charge density of the first surface (upper surface in FIG. 1) and the second surface (lower surface in FIG. 2) was in the range of −1 to 1 μC / m ² , but the charge was weak and the period was 20 to 20 It was only known to be about 30 mm.
[Example 2]
The charged film in Example 1 was cut out to 10 cm × 10 cm, and temporarily bonded to a stainless steel plate standing upright with respect to the ground by the following procedure.
(1) One surface of the film (first surface in Example 1) is brought into close contact with the stainless steel plate by hand.
(2) In the state of (1), wipe the reverse side of the film (second side in Example 1) with gauze soaked in ethyl alcohol.
(3) After confirming that the alcohol is dry by visual inspection, release the hand.

The film in Example 1 stuck to the stainless steel plate and did not peel even after 1 week or more.
[Comparative Example 2]
The film was temporarily bonded in the same manner as in Example 2 except that the charged film in Comparative Example 1 was used.

  The film in Comparative Example 2 peeled off from the stainless steel plate at the same time as the hand was released.

  The charged sheet according to the present invention is not limited to temporary bonding, but can also be charged by vapor deposition or bonding of metals, etc., and is necessary for slip control in the process, adsorption of minute objects (particles), etc. It can be applied to a wide range of applications that develop charging in various processes.

1 is a schematic cross-sectional view of an electrical insulating sheet charging apparatus according to the present invention. It is explanatory drawing which shows the structure of the charging unit of the charging processing apparatus in this invention. It is explanatory drawing which shows arrangement | positioning of the charging unit of the charging processing apparatus in this invention. It is explanatory drawing which shows the effect of the charging of the charging processing apparatus in this invention. It is explanatory drawing which shows the electrical charging state of the film in this invention at the time of making it contact with a temporary attachment destination base material. It is explanatory drawing which shows the charge state of the film in this invention in the time of completion | finish of static elimination of a 2nd surface. It is a schematic diagram showing the charged state of each surface of the sheet in the present invention. It is explanatory drawing showing distribution of the back surface equilibrium potential of each surface of the sheet | seat shown in FIG. It is a sheet bonding apparatus in the prior art. It is an apparatus for adhering a sheet to a conductive object in the prior art. 1 is a sheet charging device in the prior art. 1 is a sheet charging device in the prior art. 1 is a sheet neutralizing device in the prior art. It is a schematic explanatory drawing of the phenomenon in which the electric potential of the sheet roll body wound up by the electric double layer rises. It is a schematic explanatory drawing of the electric potential state of the sheet roll body by which the charged sheet in the present invention was wound up. It is explanatory drawing for calculating | requiring the contact | adhesion power of the charging sheet in this invention. It is the schematic of the charging electrode used for the charging unit in this invention.

Explanation of symbols

1: Charging apparatus 1a: Guide roll 1b: Guide roll 1ab: Moving direction of film 1c-1: First AC power source in the first charging unit 1c-2: First AC power source in the second charging unit 1d -1: first ion generation electrode in the first charging unit 1d-2: first ion generation electrode in the second charging unit 1d-n: first ion generation electrode in the nth charging unit (final stage charging unit) 1 ion generation electrode 1e-1: second AC power source in the first charging unit 1e-2: second AC power source in the second charging unit 1f-1: second ion generation in the first charging unit Electrode 1f-2: Second ion generating electrode in second charging unit 1f-n: Second ion in nth charging unit (final charging unit) ON generating electrode 1g-1: first shield electrode in the first charging unit 1g-2: first shield electrode in the second charging unit 1h-1: second shield electrode in the first charging unit 1h- 2: Second shield electrode in the second charging unit 1x-1: Midpoint of line segment connecting the tip of the first ion generating electrode and the tip of the second ion generating electrode in the first charging unit 1x- 2: Midpoint of line segment connecting the tip of the first ion generating electrode and the tip of the second ion generating electrode in the second charging unit 2: Charging device 2a: Ion generating electrode 2ab: Movement direction of the sheet 3: Charging device 3a: ion generation electrode 3ab: sheet moving direction 3c: ground conductor 3d: peeling discharge 4: neutralization device 4a: ion generation electrode 4b: ion generation electrode 4ab: sheet transfer Direction 5a: Electrostatic charging electrode 5b: Electrostatic charging electrode 5c: Insulating base material 5d: Sheet 5e: Sheet 5f: Conductive base material 5g: Sheet 6: Core 7a: Ion generating electrode 7b: Shield electrode 7c: High voltage core wire (Not shown)
7d: Insulating member 100: First surface (of sheet) 200: Second surface of (sheet) 101: Positive electrostatic charge (of first surface of sheet) 102: (of first surface of sheet) Negative electrostatic charge 201: Positive electrostatic charge (on the second side of the sheet) 202: Negative electrostatic charge (on the second side of the sheet) 301: Positive ions 302: Negative ions 401: (Positive) induced charges 402: (Negative) induced charge 500: Electric field line 700: Coulomb force B: Temporary bonding destination base material C: Conductor D: Conductive layer CU1: First charging unit CU2: Second charging unit CU2: nth (Final stage) charging unit d ₁ : distance between normal direction electrodes in the first charging unit d ₂ : distance between normal direction electrodes in the second charging unit d _i : normal direction electrode in the second charging unit Distance p: i-th charging unit and 2nd Charging unit center distance of the charging unit (for 2 units)
S: sheet S ₁ : first layer (innermost layer) sheet S _j : j-th layer sheet S _{1 + 1} : j + 1-th layer sheet S _f : outermost layer sheet S _m : m-th layer sheet S _{m + 1} : sheet of the (m + 1) th layer

Claims (8)

In at least a part of the in-plane direction of the sheet, the charge density of the first surface and the charge density of the second surface change smoothly and periodically in the longitudinal direction of the sheet, and the amplitude of the change in the charge density, respectively, 6μC / m ² or more 1000μC / m ² or less, and, between the first surface and the second surface in at least a portion of the plane direction of the sheet A temporary adhesive sheet, characterized in that it comprises a charged sheet having opposite charging polarities. 2. The temporary bonding according to claim 1, wherein a period in which the charge density of the first surface and the charge density of the second surface of the charging sheet changes is 10 mm or more and 100 mm or less, respectively. Sheet . In each part on the charging sheet, the sum of the charge density of the first surface and the charge density of the second surface at the same position in the in-plane direction is −2 μC / m ² or more and ² μC / m ² or less. The temporary adhesive sheet according to claim 1, wherein the temporary adhesive sheet is provided . The temporary charging sheet according to claim 1, wherein the charging sheet is obtained by bonding a plurality of sub- sheets . The first surface of the charged sheet according to any one of claims 1 to 4 is brought into contact with a temporary adhesion destination base material, and in this state, the second surface of the charged sheet is neutralized to thereby remove the charged sheet. A method for temporarily adhering a sheet, characterized by temporarily adhering to the temporary adhering substrate. The first surface of the charging sheet according to claim 4 is brought into contact with a temporary adhesion destination base material, and in this state, the sub-sheet including the second surface of the charging sheet is selected from the plurality of sub-sheets. Temporary adhesion of a sheet characterized by temporarily adhering to the temporary adhering base material a sub-sheet that remains without being peeled among the charged sheets by peeling from the sub-sheet including the first surface of the charged sheet Method. The method for temporarily adhering a sheet according to claim 5 or 6 , characterized in that the surface or the vicinity of the surface has conductivity as the temporary adhering substrate. A base material with a temporarily bonded sheet, wherein the sheet is temporarily bonded to the surface of the temporary bonding destination base material by the method for temporarily bonding a sheet according to any one of claims 5 to 7 .

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