JP2011201970A - Film surface treatment apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance treatment performance in plasma treatment of a film to be treated, such as a protective film for a polarizing plate with a reactive gas containing a polymerizable monomer.SOLUTION: A reactive gas nozzle 40 is connected to the tip of a supply pipe 30 extending from a source 21 of a reactive gas. The reactive gas nozzle 40 is faced to a treatment region 13 between electrodes 11, 12. An interposer member 50 is disposed in the reactive gas nozzle 40. The supply pipe 30 and the reactive gas nozzle body 41 are formed of a non-metal material, preferably a resin. The interposer member 50 is formed of a metal. Acrylic acid or the like capable of undergoing metal-catalyzed polymerization is used as a polymerizable monomer in the reactive gas.

Description

  The present invention relates to an apparatus for treating the surface of a film, and more particularly to a film surface treatment apparatus suitable for an adhesive improvement treatment of an optical film for an optical device such as a polarizing plate, an imparting or improving treatment of optical properties, and the like.

  Patent Document 1 describes a surface treatment method in which a polymerizable monomer such as acrylic acid is vaporized and sprayed onto a protective film for a polarizing plate, and plasma generated under the vicinity of atmospheric pressure is irradiated. For example, acrylic acid is used as the polymerizable monomer. Thereby, a polymer film of acrylic acid is formed on the surface of the protective film. This polymerized film becomes an adhesion promoting layer, and the protective film can be securely bonded to the polarizing film.

International Publication WO2009 / 008284

  Acrylic acid is activated and polymerized by plasma. When the plasma irradiation time is short, polymerization does not proceed sufficiently, and it is difficult to obtain desired processing performance (adhesiveness, etc.). If the transport speed of the film to be processed is slowed down in order to lengthen the plasma irradiation time, the processing takes time. If the voltage applied to the electrode is increased, the plasma energy can be increased, but the load applied to the withstand voltage member is increased.

The inventor has conducted intensive research and development to solve the above problems.
A polymerizable monomer such as acrylic acid has a property of causing a polymerization reaction using a metal such as iron as a catalyst. Actually, when the supply pipe from the vaporizer of acrylic acid to the blowing nozzle was constituted by a stainless steel pipe, the polymer was deposited on the inner wall of the stainless steel pipe, resulting in clogging. On the other hand, when the treatment was carried out with the supply pipe constituted by a PVC resin tube, the blockage by the polymer did not occur, but the treatment performance was not sufficient and the input voltage had to be increased.

The present invention has been made on the basis of such knowledge, and is a film surface treatment apparatus for bringing a reaction gas containing a reaction component into contact with a film to be processed disposed in a treatment region near atmospheric pressure and irradiating with plasma. There,
A pair of electrodes for generating the plasma in the processing region;
A supply pipe extending from the supply source to the treatment region, the supply pipe having a conduit connected to a supply source of a reaction gas containing a polymerizable monomer that can be polymerized using a metal as a catalyst;
A reaction gas nozzle that faces the processing region, and has a blow-out passage that is continuous with the pipe;
An interposition member provided in the reaction gas nozzle or the supply pipe and defining a part of the blow-out path or the pipe path;
A portion defining the conduit of the supply pipe and a portion defining the outlet passage of the reaction gas nozzle are made of a non-metallic material, and the interposition member is made of metal. It is characterized by being.

When the reactive gas passes through a portion other than the supply pipe and the intervening member of the reactive gas nozzle, it is possible to avoid or suppress the polymerization reaction of the polymerizable monomer from being induced. When the reaction gas comes into contact with the interposed member, the polymerization reaction of the polymerizable monomer is induced by the catalytic action of the metal constituting the interposed member, and the dimerization or polymerization of the polymerizable monomer occurs in the reaction gas. This reactive gas is blown out from the reactive gas nozzle to the processing region to come into contact with the film to be processed and is irradiated with plasma. As a result, the polymerization of the polymerizable monomer further proceeds, and a polymer film of the polymerizable monomer is formed on the surface of the film to be processed. Since the polymerizable monomer is induced to undergo a polymerization reaction in the reaction gas supply path prior to the plasma irradiation, the polymerization on the film to be processed is promoted. Thus, a polymer film having a high degree of polymerization can be reliably formed on the surface of the film to be processed. As a result, processing performance (for example, improvement in adhesion of the film to be processed) can be enhanced.
It is not necessary to lengthen the plasma irradiation time, and processing can be performed at high speed.
Since sufficient processing performance can be obtained without increasing the voltage applied to the electrodes, the load on the withstand voltage member used for insulating the electrodes can be reduced, and deterioration and damage of the withstand voltage member can be suppressed.
On the reaction gas supply path, the portion where the polymerized polymerizable monomer is deposited can be concentrated on the surface of the interposed member. It is possible to prevent clogging due to accumulation of a polymer in an uncertain part of the reaction gas supply path, and maintenance can be easily performed.

It is preferable that the interposition member is a pressure loss member that imparts a flow resistance to the reaction gas.
By narrowing the flow passage cross-sectional area in the blow-out passage or the pipe passage in the interposed member, the reaction gas and thus the polymerizable monomer can be surely brought into contact with the interposed member. Therefore, the polymerization reaction of the polymerizable monomer can be surely induced.

It is preferable that the interposition member is provided at a distal end portion of the supply pipe or the reaction gas nozzle.
Thereby, the path length from the interposing member to the outlet of the reactive gas nozzle can be shortened, and the reactive gas can be led to the treatment region before the polymerization of the polymerizable monomer proceeds excessively. The amount of the polymer adhering to the pipe line or the outlet path downstream from the interposed member can be suppressed.

The interposition member is preferably separable from the supply pipe or the reaction gas nozzle.
When the polymer is deposited to some extent on the interposition member, the interposition member can be removed from the supply pipe or the reaction gas nozzle and replaced or cleaned. Therefore, maintenance can be further facilitated.

The present invention is suitable for the treatment of hard-to-adhere optical resin films. In adhering the hard-to-adhesive optical resin film to the easily-adhesive optical resin film, It is suitable for improving.
Examples of the main component of the hardly adhesive optical resin film include triacetate cellulose (TAC), polypropylene (PP), polyethylene (PE), cycloolefin polymer (COP), cycloolefin copolymer (COC), and polyethylene terephthalate. (PET), polymethyl methacrylate (PMMA), polyimide (PI) and the like.

  Examples of the main component of the easily adhesive optical resin film include polyvinyl alcohol (PVA) and ethylene vinyl acetate copolymer (EVA).

In the surface treatment or the like for improving the adhesiveness of the hardly adhesive optical resin film, it is preferable that a reactive gas containing a polymerizable monomer as a reaction component is brought into contact with the film and plasma irradiation is performed.
Examples of the polymerizable monomer for improving adhesion include monomers having an unsaturated bond and a predetermined functional group. The predetermined functional group is preferably selected from a hydroxyl group, a carboxyl group, an acetyl group, a glycidyl group, an epoxy group, an ester group having 1 to 10 carbon atoms, a sulfone group, and an aldehyde group. A hydrophilic group is preferred.
Examples of the monomer having an unsaturated bond and a hydroxyl group include ethylene glycol methacrylate, allyl alcohol, and hydroxyethyl methacrylate.
Examples of the monomer having an unsaturated bond and a carboxyl group include acrylic acid, methacrylic acid, itaconic acid, maleic acid, 2-methacryloylpropionic acid and the like.
Examples of the monomer having an unsaturated bond and an acetyl group include vinyl acetate.
Examples of the monomer having an unsaturated bond and a glycidyl group include glycidyl methacrylate.
Monomers having an unsaturated bond and an ester group include methyl acrylate, ethyl acrylate, butyl acrylate, t-butyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, methyl methacrylate, ethyl methacrylate, methacrylic acid. Examples include butyl, t-butyl methacrylate, isopropyl methacrylate, and 2-ethyl methacrylate.
Examples of the monomer having an unsaturated bond and an aldehyde group include acrylic aldehyde and crotonaldehyde.

In the present invention, a polymerizable monomer that can be polymerized using a metal as a catalyst is used.
Examples of the polymerizable monomer that can be polymerized using a metal as a catalyst include acrylic acid and methacrylic acid.

It is preferable that the non-metallic material has substantially no catalytic action for the polymerization reaction of the polymerizable monomer. Here, the fact that the non-metallic material does not have a catalytic action is small enough that the catalytic action of the non-metallic material is negligible compared to the case where the non-metallic material has no catalytic action as well as the catalytic action of the metal constituting the interposed member. Including cases.
Resin, ceramics, etc. are mentioned as a nonmetallic material which comprises the said supply pipe | tube. Examples of the resin constituting the supply pipe include PVC (polyvinyl chloride), PFA (perfluoroalkoxy alkane), PU (polyurethane), PE (polyethylene), and PP (polypropylene).
Resin, ceramics, etc. are mentioned as a nonmetallic material which comprises the said reactive gas nozzle. Examples of the resin constituting the reaction gas nozzle include PVC (polyvinyl chloride), PFA (perfluoroalkoxy alkane), PU (polyurethane), PE (polyethylene), PP (polypropylene), and the like.

  Examples of the metal material constituting the interposed member include aluminum, stainless steel, iron, steel, copper, and brass.

The surface treatment is preferably performed near atmospheric pressure. Here, the vicinity of atmospheric pressure refers to a range of 1.013 × 10 ⁴ Pa to 50.663 × 10 ⁴ Pa, and considering the ease of pressure adjustment and the simplification of the apparatus configuration, 1.333 × 10 ^4. Pa~10.664 × ¹⁰ 4 Pa, and more preferably from ^{9.331 × 10 4 Pa~10.397 × 10 4} Pa.

The polymerizable monomer may be conveyed by a carrier gas. The carrier gas is preferably selected from an inert gas such as nitrogen, argon or helium. From the economical viewpoint, it is preferable to use nitrogen as the carrier gas.
Many polymerizable monomers such as acrylic acid and methacrylic acid are in a liquid phase at normal temperature and pressure. Such a polymerizable monomer may be vaporized in a carrier gas such as an inert gas. As a method of vaporizing the polymerizable monomer into the carrier gas, a method of extruding a saturated vapor on the surface of the polymerizable monomer solution with the carrier gas, a method of bubbling the carrier gas into the polymerizable monomer solution, a polymerizable monomer solution For example, a method of promoting evaporation by heating can be used. Extrusion and heating, or bubbling and heating may be used in combination.

  When heating and vaporizing, it is preferable to select a polymerizable monomer having a boiling point of 300 ° C. or less in consideration of the burden on the heater. Moreover, it is preferable to select a polymerizable monomer that does not decompose (chemically change) by heating.

  ADVANTAGE OF THE INVENTION According to this invention, a to-be-processed film can be processed at high speed, and processing performance can be improved. It is possible to prevent clogging of indefinite portions of the reaction gas supply path, and it is possible to operate stably for a long period of time. Furthermore, the load applied to the withstand voltage member can be reduced.

It is a side view which shows schematic structure of the film surface treatment apparatus which concerns on 1st Embodiment of this invention. It is a plane sectional view which meets the II-II line of FIG. It is a side view which shows schematic structure of the film surface treatment apparatus which concerns on 2nd Embodiment of this invention. It is a plane sectional view showing the modification of the pressure loss way of the intervention member of the above-mentioned film surface treatment device. It is a side view which shows the modification of an intervention member. It is a side view which shows the modification of an intervention member.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a first embodiment of the present invention. The to-be-processed film 9 is an optical transparent resin film, and has a continuous sheet shape. Here, a protective film for a polarizing plate is applied as the film 9 to be processed. The protective film 9 contains triacetate cellulose (TAC) as a main component. The components of the film 9 are not limited to TAC, but polypropylene (PP), polyethylene (PE), cycloolefin polymer (COP), cycloolefin copolymer (COC), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyimide (PI), or the like may be used. The thickness of the film 9 is, for example, about 100 μm.

  A polarizing film made of a PVA film and a protective film are bonded together with an adhesive to constitute a polarizing plate. As the adhesive, an aqueous adhesive such as an aqueous PVA solution is used. Prior to the bonding step, the protective film is surface-treated by the film surface treatment system 1 to improve the adhesion of the protective film.

  As shown in FIG. 1, the film surface treatment apparatus 1 includes a treatment unit 10 and a reaction gas supply system 20. The processing unit 10 includes a pair of electrodes 11 and 12. The electrodes 11 and 12 are both constituted by cylindrical roll electrodes. Roll electrodes 11 and 12 are arranged in parallel to each other. Hereinafter, a direction along the axis of the electrodes 11 and 12 is appropriately referred to as a “process width direction” (see FIG. 2). A narrow gap 13 (processing region) is formed between the roll electrodes 11 and 12. One of the pair of electrodes 11 and 12 is connected to a power source (not shown). The other electrode is electrically grounded. The power source supplies, for example, pulsed power to the electrodes 11 and 12. As a result, an electric field is applied between the pair of electrodes 11, 12, plasma is generated in the interelectrode gap 13 near atmospheric pressure, and the interelectrode gap 13 becomes a discharge space near atmospheric pressure. Although illustration is omitted, the processing unit 10 is provided with one or a plurality of voltage-resistant members made of an insulator, and the insulating properties of the electrodes 11, 12 and the like are ensured.

  The film 9 to be processed is wound around the upper peripheral surface of the roll electrodes 11 and 12 by about a half turn with the width direction in the processing width direction orthogonal to the paper surface of FIG. The film to be treated 9 is passed through the discharge space 13 along the peripheral surfaces of the roll electrodes 11 and 12, is hung below the discharge space 13, and is folded back by the guide rolls 15 and 15. The roll electrodes 11 and 12 are rotated in the same direction (clockwise in FIG. 1) around their own axes and in synchronization with each other. Thereby, the to-be-processed film 9 is conveyed from the roll electrode 11 to the roll electrode 12. FIG.

  Each roll electrode 11, 12 incorporates film temperature adjusting means (not shown). The film temperature adjusting means is constituted by a temperature adjusting path formed in, for example, the roll electrodes 11 and 12. The temperature of the roll electrodes 11 and 12 can be controlled by flowing a temperature-controlled medium such as water through the temperature control path. As a result, the to-be-processed film 9 on the peripheral surface of the roll electrodes 11 and 12 can be temperature-controlled. The set temperature of the electrodes 11 and 12 and thus the film 9 to be processed is preferably lower than the condensation temperature of acrylic acid AA, for example, 20 to 25 ° C.

The reactive gas supply system 20 includes a reactive gas supply source 21 and a supply path unit 22. The reactive gas supply source 21 is composed of a vaporizer. In the vaporizer 21, acrylic acid (CH ₂ = CHCOOH) is stored in a liquid state as a polymerizable monomer. The vaporizer 21 incorporates a heater (not shown), and the acrylic acid AA is kept at a constant temperature. The temperature of acrylic acid AA in the vaporizer 21 is, for example, 120 ° C. to 190 ° C.

A carrier gas source 23 is connected to the vaporizer 21. The carrier gas source 23 stores nitrogen (N ₂ ) as a carrier gas. A carrier path 24 and a bypass path 25 branch from the carrier gas source 23 and extend. A carrier path 24 is connected to the vaporizer 21. The carrier gas (N ₂ ) from the carrier gas source 23 is introduced into the vaporizer 21 via the carrier path 24. Acrylic acid is vaporized and mixed with this carrier gas (N ₂ ) to generate a reaction gas (acrylic acid AA + N ₂ ). The carrier gas may be introduced above the liquid acrylic acid level in the vaporizer 21, or may be introduced into the liquid acrylic acid and bubbled.
As the carrier gas, a rare gas such as Ar or He may be used instead of N ₂ .

  The supply path unit 22 includes a supply pipe 30 and a reactive gas nozzle 40. The supply pipe 30 includes a pipe body 31, one or a plurality of pipe joints 32 (only one is shown in the figure), and a connection port 33. A supply pipe main body 31 extends from the vaporizer 21 to the processing unit 10. A pipe joint 32 is provided in the middle of the supply pipe main body 31. A connection port 33 is provided at the end of the supply pipe main body 31. These supply pipe constituting members 31, 32, 33 form a pipe line 39 for sending the reaction gas from the vaporizer 21 to the reaction gas nozzle 40. A proximal end portion of the conduit 39 is connected to the inside of the vaporizer 21.

A bypass path 25 is connected to one pipe joint 32. Part of the carrier gas (N ₂ ) joins the supply pipe 30 at the pipe joint 32 without passing through the vaporizer 21. The acrylic acid concentration in the reaction gas can be adjusted by the distribution ratio of the carrier gas to the carrier path 24 and the bypass path 25 in addition to the temperature of the vaporizer 21. The bypass path 25 may be omitted, and the entire carrier gas may pass through the vaporizer 21.

  The supply pipe 30 is made of resin (non-metallic material). Specifically, the supply pipe body 31 is made of PVC (polyvinyl chloride). The pipe joint 32 and the connection port 33 are made of PFA (perfluoroalkoxy alkane).

The supply pipe 30 is temperature-controlled by temperature control means (not shown) such as a ribbon heater. The set temperature of the supply pipe 30 is preferably higher than the condensation temperature of acrylic acid, and is, for example, 55 ° C to 70 ° C.

  A reaction gas nozzle 40 is connected to the tip of the supply pipe 30. The reactive gas nozzle 40 is disposed above the discharge space 13 between the roll electrodes 11 and 12. The reactive gas nozzle 40 has a nozzle body 41. As shown in FIGS. 1 and 2, the reactive gas nozzle main body 41 has a container shape that extends long in the processing width direction (direction perpendicular to the paper surface of FIG. 1). A cross section perpendicular to the extending direction of the reactive gas nozzle body 41 is tapered downward. As shown in FIG. 1, the lower end portion (tip portion) of the reactive gas nozzle body 41 is inserted into a gradually narrowing portion between the roll electrodes 11 and 12 and faces the discharge space (processing region) 13. A blowout passage 49 is formed inside the reaction gas nozzle body 41. A connection port 33 is provided on the upper surface of the reaction gas nozzle 40. The upstream end of the blow-out path 49 is connected to the connection port 33, and thus continues to the pipe line 39. The downstream end of the blow-out passage 49 reaches the lower end surface of the reaction gas nozzle 40 and forms a blow-out port 49a. The blowout port 49a has a slit shape extending in the processing width direction (direction orthogonal to the paper surface of FIG. 1).

  An interposition member 50 is provided inside the reaction gas nozzle body 41. Although not shown in detail, the interposition member 50 is detachably connected to and supported by the reaction gas nozzle body 41 via screws, hooks, steps, fitting portions, and the like. The interposed member 50 has a flat plate shape that extends long in the processing width direction (a direction orthogonal to the paper surface of FIG. 1). The short side direction of the interposed member 50 is directed to the opposing direction of the electrodes 11 and 12. The thickness direction of the interposed member 50 is directed upward and downward.

  The interposition member 50 is interposed in the middle of the blowing path 49. By means of the interposing member 50, the inside of the container-like reaction gas nozzle main body 41 (blowing path 49) is partitioned vertically. As shown in FIG. 2, the interposed member 50 is formed with a pressure loss path including a large number of small-diameter dispersion holes 51. The dispersion holes 51 are arranged at regular intervals in the longitudinal direction and the short direction of the interposed member 50. Each dispersion hole 51 penetrates the interposed member 50 in the thickness direction (up and down). The axial length of the dispersion hole 51 (the thickness of the interposition member 50) is extremely small with respect to the entire path length of the supply path portion 22. A chamber 49 a above the interposition member 50 in the blowout passage 49 and a chamber 49 b below the interposition member 50 are connected via the dispersion hole 51. The total cross-sectional area of all the dispersion holes 51 is sufficiently smaller than the cross-sectional areas of the upper and lower chambers 49a and 49b. The interposed member 50 constitutes a pressure loss member that imparts flow resistance to the reaction gas. The upper surface of the interposed member 50, the inner peripheral surface of the dispersion hole 51, and the lower surface define a part of the blowout path 49.

  The flow path length from the interposition member 50 to the blowout opening 49a at the tip (lower end) of the blowout path 49 is sufficiently shorter than the flow path length of the entire supply path section 22.

The reactive gas nozzle 40 is made of resin (non-metallic member) except for the interposing member 50. Specifically, the reactive gas nozzle body 41 is made of PVC (polyvinyl chloride).
The interposed member 50 is made of metal. Here, the intervention member 50 is made of aluminum, but may be made of stainless steel, iron, steel, or the like. The interposition member 50 is disposed on the side (base end side) opposite to the air outlet 49 c in the nozzle 40, and insulation between the metal interposition member 50 and the electrodes 11 and 12 is ensured.

The reaction gas nozzle 40 is temperature-controlled by nozzle temperature adjusting means (not shown). The nozzle temperature adjusting means is constituted by a temperature adjusting path through which a temperature-controlled medium such as water is passed, but may be an electric heater. The set temperature of the reaction gas nozzle 40 is preferably higher than the condensation temperature of acrylic acid, and is, for example, 50 ° C to 55 ° C.

A method for surface-treating the film 9 to be processed by the film surface treatment apparatus 1 having the above configuration will be described.
The film 9 to be processed is wound around the roll electrodes 11 and 12 and the guide roll 15.
The roll electrodes 11 and 12 are rotated clockwise in FIG. 1, and the film 9 to be processed is conveyed substantially in the right direction.

In the vaporizer 21 to the carrier gas _{(N 2)} to vaporize acrylic acid (AA), to produce a reaction gas (AA + _{N 2).} This reaction gas is sent from the vaporizer 21 to the pipe line 39 of the supply pipe 30. In the middle of the supply pipe 30, the carrier gas (N ₂ ) from the bypass path 25 is merged with the reaction gas. Further, the reaction gas (AA + N ₂ ) is caused to flow downstream of the supply line 39.

  Resins such as PVC and PFA constituting the supply pipe 30 do not have a catalytic action on the polymerization reaction of acrylic acid. Therefore, even if acrylic acid as a reaction gas flowing through the supply pipe 30 comes into contact with the inner wall of the supply pipe 30, the acrylic acid polymerization reaction hardly occurs. Therefore, it is possible to avoid or suppress the accumulation of the acrylic acid polymer on the inner wall of the supply pipe 30, and to avoid or suppress the blockage of the supply pipe 39. Thereby, the flow of the reaction gas in the supply pipe 30 can be stabilized over a long period of time.

  The reaction gas is introduced from the supply pipe 39 into the blowout passage 49 in the reaction gas nozzle 40. The reaction gas diffuses in the treatment width direction in the diffusion chamber 49 a of the blow-out passage 49. Subsequently, the reaction gas passes through each dispersion hole 51 of the interposed member 50. At this time, the reaction gas is given flow resistance and causes pressure loss. The reaction gas exiting from each dispersion hole 51 diffuses again while joining in the diffusion chamber 49b. Thereby, the flow of the reaction gas can be made uniform in the process width direction.

The reaction gas contacts the inner wall of the reaction gas nozzle body 41 and the surface of the interposition member 50 (the upper surface and the lower surface of the interposition member 50 and the inner peripheral surface of the dispersion hole 51) in the flow process in the blowout passage 49.
The resin such as PVC constituting the reaction gas nozzle body 41 does not have a catalytic action for the polymerization reaction of acrylic acid. Therefore, even when acrylic acid in the reaction gas comes into contact with the inner wall of the reaction gas nozzle body 41, the polymerization reaction of acrylic acid is hardly induced. Therefore, it is possible to avoid or suppress the deposition of the acrylic acid polymer on the inner wall of the reaction gas nozzle main body 41, and to avoid or suppress the blockage of the blowing passage 49.

  On the other hand, the metal material such as aluminum constituting the interposed member 50 has a catalytic action for the polymerization reaction of acrylic acid. Therefore, when acrylic acid in the reaction gas comes into contact with the interposition member 50, a polymerization reaction of acrylic acid is induced by the catalytic action of the metal material. In particular, since the interposition member 50 constitutes a pressure loss member in the blowout passage 49, the reaction gas, and thus acrylic acid, reliably contacts the interposition member 50. Therefore, the polymerization reaction of acrylic acid can be reliably induced. Thereby, dimerization or polymerization of the acrylic acid monomer occurs in the reaction gas.

  Soon after the induction of the polymerization reaction, the reaction gas reaches the outlet 49a at the tip (lower end) of the outlet passage 49. Therefore, the reaction gas can be blown out before the polymerization of acrylic acid proceeds excessively. The amount of the polymer adhering to the blowing passage 49 downstream from the interposition member 50 can be suppressed. The flow of reactant gas is uniformly distributed in the process width direction. This reactive gas is introduced into the interelectrode gap 13 and comes into contact with the film 9 to be processed in the interelectrode gap 13.

In parallel, power is supplied to the electrodes 11 and 12 from a power source (not shown), an electric field is applied between the electrodes 11 and 12, and a plasma discharge near atmospheric pressure is generated in the gap 13. Thereby, the polymerization reaction of acrylic acid further proceeds. Also, nitrogen in the reaction gas is turned into plasma. The film 9 to be treated is irradiated with the nitrogen plasma or plasma light, and bonds such as C—C, C—O, and C—H of the surface molecules of the film 9 to be treated are cut. It is considered that a polymer of acrylic acid is bonded (graft polymerization) to this bond cutting part, or a COOH group decomposed from acrylic acid is bonded. Thereby, an adhesion promoting layer is formed on the surface of the film 9 to be processed. Since acrylic acid is induced to be polymerized in the interposed member 50 prior to the plasma irradiation, the degree of polymerization on the film 9 can be increased. Therefore, the adhesion promoting layer can be reliably formed.
It is not necessary to lengthen the plasma irradiation time, the conveyance speed of the film 9 can be increased, and processing can be performed at high speed.
The degree of polymerization of acrylic acid can be sufficiently increased without increasing the voltage applied to the electrodes 11 and 12. Therefore, the load applied to the withstand voltage member of the processing unit 10 can be alleviated, and deterioration and damage of the withstand voltage member can be suppressed.

  A polarizing plate is produced by bonding the treated film 9 after treatment with a polarizing film made of a PVA film or the like. An aqueous adhesive such as an aqueous PVA solution is used as the adhesive. Since the adhesiveness of the film to be treated 9 is enhanced in advance by the surface treatment, a polarizing plate having sufficient adhesive strength can be obtained.

  In the supply path portion 22, the place where the acrylic acid polymer is deposited can be concentrated on the surface of the interposed member 50. It is possible to prevent the polymer from being deposited at an uncertain location of the supply path section 22. Therefore, if the interposition member 50 is periodically replaced or cleaned, the reaction gas flow in the supply path portion 22 can be stably maintained over a long period of time, and maintenance is easy.

  Next, another embodiment of the present invention will be described. In the following embodiments, the same reference numerals are attached to the drawings for the same contents as those of the above-described embodiments, and the description thereof is omitted.

  In the first embodiment, the discharge space 13 between the electrodes 11 and 12 and the processing region coincide with each other, but the processing region may include the discharge space 13 and be wider than the discharge space 13. The pair of electrodes 11 and 12 is not limited to defining the entire processing region, and it is only necessary to define at least a part of the processing region (plasma irradiation region portion). The reactive gas spray region and the plasma irradiation region in the processing region may be separated.

  FIG. 3 shows a second embodiment of the present invention. In the film surface treatment apparatus 1 </ b> A of the second embodiment, the reactive gas spray area is separated from the plasma irradiation area 13 between the electrodes 11 and 12, and is disposed upstream of the plasma irradiation area 13 in the film conveyance direction. Has been. More specifically, the reaction gas nozzle 40 of the supply path portion 22 is disposed away from the discharge space 13 on the upstream side in the rotation direction of the roll electrode 11. The front end surface (lower surface) of the reactive gas nozzle 40 is disposed to face the upper peripheral surface of the roll electrode 11.

  A portion between the position facing the nozzle 40 on the peripheral surface of the roll electrode 11 and the discharge space 13 along the film conveyance direction constitutes a processing region 14. A portion of the peripheral surface of the roll electrode 11 facing the nozzle 40 is a reactive gas spray region.

  The point that the metal-made interposing member 50 is provided in the resin-made reactive gas nozzle body 41 is the same as in the first embodiment.

The film surface treatment apparatus 1 </ b> A further includes a discharge generated gas supply system 70. The discharge generated gas supply system 70 includes a discharge generated gas source 71, a supply path 72, and a nozzle 73. The discharge generated gas source 71 stores a discharge generated gas. Nitrogen (N ₂ ) is used as the discharge product gas. The discharge product gas does not contain a polymerizable monomer. One nitrogen gas source may serve as both the discharge generation gas source 71 and the carrier source 23.
The discharge generated gas is not limited to nitrogen, and a rare gas such as argon or helium may be used.

  A discharge generation gas supply path 72 extends from the discharge generation gas source 71 to the processing unit 10. The pipe member constituting the supply path 72 may be made of metal or resin. A discharge generated gas nozzle 73 is connected to the tip of the path 72. Each component of the discharge generated gas nozzle 73 may be made of metal or non-metal such as resin, but the portions close to the electrodes 11 and 12 are preferably made of an insulating material such as resin. The shape of the discharge generated gas nozzle 73 is substantially the same as that of the nozzle 40 of the first embodiment, and extends in the processing width direction orthogonal to the paper surface of FIG. The discharge generation gas nozzle 73 is disposed above the discharge space 13 between the roll electrodes 11 and 12 (position of the reaction gas nozzle 40 in the first embodiment). The tip of the discharge generation gas nozzle 73 faces the discharge space 13.

In the film surface treatment apparatus 1 </ _b > A, a reaction gas (acrylic acid + N ₂ ) is passed through the supply path portion 22 and sprayed from the reaction gas nozzle 40 onto the film to be treated 9 on the upper peripheral surface of the roll electrode 11. The acrylic acid in the reaction gas is condensed on the film 9 to be processed and adheres to the surface of the film 9 to be processed. A part of acrylic acid is dimerized or polymerized by the catalytic action of the interposed member 50.

At the same time, the discharge generated gas (N ₂ ) of the discharge generated gas source 71 is supplied from the nozzle 73 to the discharge space 13 through the supply path 72 to be turned into plasma. The acrylic acid adhering portion of the film to be processed 9 eventually enters the discharge space 13 and receives plasma irradiation. Thereby, the polymerization reaction of acrylic acid further proceeds. Since polymerization is induced in the intervening member 50, the degree of polymerization of acrylic acid in the discharge space 13 can be increased as in the first embodiment.

Next, the deformation | transformation aspect of an intervention member is demonstrated.
The pressure loss path of the interposing member 50 according to the first and second embodiments is not limited to a large number of small hole-like dispersion holes 51, and may be slits 52 as shown in FIG. The slit 52 extends in the processing width direction and penetrates the interposed member 50 in the thickness direction (a direction orthogonal to the paper surface of FIG. 4).

The interposed member is not limited to being provided in the reactive gas nozzle 40, and may be provided in the supply pipe 30. In this case, the pressure loss member 50 in the reaction gas nozzle 40 may be made of resin such as PVC.
In the embodiment shown in FIG. 5, a cartridge 60 is interposed in the supply pipe 30. The cartridge 60 is provided at the distal end portion (portion close to the reaction gas nozzle 40) of the supply pipe 30. The cartridge 60 is detachably connected to the supply pipe main bodies 31 on both sides of the cartridge 60 through a screw joint 63. The supply pipe main body 31 on the upstream side and the downstream side is connected to the inside of the cartridge 60 with the cartridge 60 interposed therebetween. The internal space of the cartridge 60 constitutes a part of the supply conduit 39. The container body of the cartridge 60 is made of a resin such as PVC or PFA, but may be made of a metal such as aluminum. A spiral interposition member 61 is accommodated in the cartridge 60. The spiral interposed member 61 is made of a metal such as aluminum, stainless steel, steel, or iron. The spiral interposed member 61 is interposed in the supply pipeline 39. A peripheral surface of the spiral interposed member 61 defines a part of the supply conduit 39.

  The reactive gas is introduced into the cartridge 60 through the supply pipe 30 upstream of the cartridge 60. This reactive gas contacts the spiral interposed member 61 while flowing through the cartridge 60. The flow of the reaction gas becomes turbulent around the spiral interposed member 61. Therefore, the acrylic acid in the reaction gas is surely brought into contact with the interposed member 61. At this time, the polymerization reaction of acrylic acid in the reaction gas is induced by the catalytic reaction of the metal constituting the interposed member 61. Thereafter, the reaction gas is blown out through the supply pipe 30 and the reaction gas nozzle 40 downstream from the cartridge 60. Similarly to the first and second embodiments, the polymerization reaction of acrylic acid on the film to be processed 9 can be promoted by inducing the polymerization reaction in the interposed member 61.

  During maintenance, the cartridge 60 is removed from the supply pipe 30. After replacing or cleaning the spiral interposing member 61 in the cartridge 60, the cartridge 60 is remounted on the supply pipe 30. Alternatively, the entire cartridge 60 may be replaced with a new one. Since it is a cartridge type, maintenance can be easily performed.

The interposition member accommodated in the cartridge 60 is not limited to a spiral member.
In the embodiment shown in FIG. 6, steel wool 62 is accommodated in the cartridge 60 as an interposed member. A continuous passage is formed in the steel wool 62. As the reaction gas passes through a continuous passage in the steel wool 62, acrylic acid contacts the steel wool 62 and a polymerization reaction is induced by the catalytic action of the steel. By making the steel wool 62 dense, the contact of acrylic acid and thus the polymerization reaction can surely occur.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, a plurality of intervention members may be provided. An interposed member may be provided in each of the reactive gas nozzle 40 and the supply pipe 30.
The intervening member may be a metal film or a metal plate provided on the inner wall of the outlet passage 49 of the reactive gas nozzle 40 or the inner wall of the conduit 39 of the supply pipe 30.
It is only necessary that at least the inner surface portion that defines the blow-out passage 49 in the reaction gas nozzle 40 or at least the inner surface portion that defines the conduit 39 in the supply pipe 30 is made of a non-metallic material such as resin. Portions that do not define the blowing passage 49 such as the outer peripheral portion of the reaction gas nozzle 40 may be made of metal as long as insulation from the power supply electrode is ensured. Portions such as the outer periphery of the supply pipe 30 that do not define the pipeline 39 may be made of metal.
A plurality of embodiments may be combined with each other. For example, a spiral interposed member 61 (FIG. 4) or an interposed member 62 (FIG. 5) made of steel wool may be provided in the reaction gas nozzle 40.

The structure of the processing unit 10 can be modified as appropriate. For example, in the first embodiment, the reactive gas nozzle 40 may be disposed at a lower portion than the discharge space 13 between the roll electrodes 11 and 12. In the second embodiment, the discharge generation gas nozzle 73 may be arranged in a lower part than the discharge space 13 between the roll electrodes 11 and 12. Nozzles may be provided above and below the discharge space 13, respectively.
Three roll electrodes and the like are provided side by side to form two discharge spaces 13, a reactive gas containing a polymerizable monomer is supplied to the discharge space 13 upstream of the transport direction, and the polymerizable monomer is supplied to the discharge space 13 downstream of the transport direction It is also possible to supply a discharge product gas that does not contain the gas. In this case, the part from the discharge space 13 of the front | former stage to the discharge space 13 of the back | latter stage comprises a process area | region along a film conveyance direction.

  The electrode structure of the processing unit 10 is not limited to the roll electrodes 11 and 12 but may be a parallel plate electrode, a pair of a roll electrode and a plate electrode, or a pair of a roll electrode and a partial cylindrical concave electrode.

Examples will be described, but the present invention is not limited to the following examples.
The film surface treatment apparatus 1 shown in FIGS. 1 and 2 was used. The reactive gas nozzle body 41 was made of PVC resin. The pressure loss member (interposition member) 50 was made of aluminum. The dimensional configuration of the pressure loss member 50 was as follows.
Length in the processing width direction of the pressure loss member 50: 317 mm
Length of the pressure loss member 50 in the short direction: 10 mm
Pressure loss member 50 thickness: 5 mm
Dispersion hole 51 diameter: 1 mm
Dispersion hole 51 pitch in the processing width direction: 14 mm
Spacing between two rows of dispersion holes 51: 6 mm

Acrylic acid was used as the polymerizable monomer for the reaction gas, and nitrogen (N ₂ ) was used as the carrier gas.
A TAC film was used as the film 9 to be processed. The width of the TAC film 9 was 325 mm.
Other processing conditions are as follows.
Reaction gas flow rate: 20 slm
Acrylic acid input in reaction gas: 4 g / min
Temperature of vaporizer 21: 160 ° C
Supply pipe 30 temperature: 75 ° C.
Temperature of the reaction gas nozzle 40: 55 ° C
Temperature of TAC film 9: 25 ° C
TAC film 9 transport speed: 10 m / min
Input power: 1850W (DC 500V, 3.8A converted into AC)
Applied voltage between electrodes 11 and 12: Vpp = 18 kV
Gap between electrodes 11 and 12: 1 mm

  The to-be-processed TAC film 9 subjected to the surface treatment by the film surface treatment apparatus 1 was bonded to one side of the PVA film. As the adhesive, an aqueous solution obtained by mixing (A) a 5 wt% PVA aqueous solution with a polymerization degree of 500 and (B) a 2 wt% aqueous sodium carboxymethylcellulose solution was used. The mixing ratio of (A) and (B) was (A) :( B) = 20: 1. The adhesive was dried at 80 ° C. for 5 minutes. A saponified TAC film was bonded to the opposite surface of the PVA film with the same adhesive as described above. Thereby, a polarizing plate sample having a three-layer structure was produced. The width of the polarizing plate sample was 25 mm. Sample pieces were cut out from five places in the width direction of the film 9 to be processed, and five polarizing plate samples were prepared.

After the adhesive was cured, the adhesive strength between the treated TAC film 9 and the PVA film of each sample was measured by the floating roller method (JIS K6854).
As a result of the measurement, the average adhesive strength was 7.68 N / 25 mm.

[Comparative Example 1]
In Comparative Example 1, the pressure loss member 50 was made of PVC resin instead of aluminum. The other processing conditions were the same as in Example 1. The sample preparation procedure and measurement method after treatment were also the same as in Example 1.
As a result of the measurement, the adhesive strength was 6.77 N / 25 mm on average.

In Example 2, the conveyance speed of the film 9 was 15 m / min. The other processing conditions were the same as in Example 1. The sample preparation procedure and measurement method after treatment were also the same as in Example 1.
As a result of the measurement, the adhesive strength was 5.00 N / 25 mm on average.

[Comparative Example 2]
In Comparative Example 2, the pressure loss member 50 was made of PVC resin instead of aluminum. The other processing conditions were the same as in Example 2 (film transport speed: 15 m / min). The sample preparation procedure and measurement method after treatment were also the same as in Example 2.
As a result of the measurement, the adhesive strength was 3.63 N / 25 mm on average.

  From the above results, it was confirmed that high processing performance (adhesive strength) can be obtained according to the present invention.

  The present invention can be applied to manufacture of an optical device such as a polarizing plate of a flat panel display (FPD).

1, 1A Film surface treatment apparatus 9 Film to be treated 10 Processing section 11, 12 Roll electrode 13 Gap between electrodes (processing area)
14 treatment area 15 guide roll 20 reaction gas supply system 21 vaporizer (reaction gas supply source)
22 Supply path 23 Carrier gas source 24 Carrier path 25 Bypass path 30 Supply pipe 31 Pipe body 32 Pipe joint 33 Connection port 39 Pipe 40 Reaction gas nozzle 41 Nozzle body 49 Outlet path 49a Upper diffusion chamber 49b Lower diffusion chamber 49c Outlet 50 Interposition member 51 Dispersion hole (pressure loss path)
52 Dispersion slit (pressure loss path)
60 Cartridge 61 Spiral interposed member 62 Steel wool (intervening member)
63 Threaded joint 70 Discharge generated gas supply system 71 Discharge generated gas source 72 Discharge generated gas supply path 73 Discharge generated gas nozzle

Claims (5)

A film surface treatment apparatus for bringing a reaction gas containing a reaction component into contact with a film to be processed disposed in a treatment region near atmospheric pressure, and irradiating plasma,
A pair of electrodes for generating the plasma in the processing region;
A supply pipe extending from the supply source to the treatment region, the supply pipe having a conduit connected to a supply source of a reaction gas containing a polymerizable monomer that can be polymerized using a metal as a catalyst;
A reaction gas nozzle that faces the processing region, and has a blow-out passage that is continuous with the pipe;
An interposition member provided in the reaction gas nozzle or the supply pipe and defining a part of the blow-out path or the pipe path;
A portion defining the conduit of the supply pipe and a portion defining the outlet passage of the reaction gas nozzle are made of a non-metallic material, and the interposition member is made of metal. A film surface treatment apparatus characterized by comprising:   The film surface treatment apparatus according to claim 1, wherein the interposition member is a pressure loss member that imparts flow resistance to the reaction gas.   The film surface treatment apparatus according to claim 1, wherein the interposition member is provided at a distal end portion of the supply pipe or the reaction gas nozzle.   The film surface treatment apparatus according to claim 1, wherein the interposition member is separable from the supply pipe or the reaction gas nozzle.   The film surface treatment apparatus according to claim 1, wherein the polymerizable monomer is acrylic acid.