JPWO2012117933A1 - Film surface treatment method and apparatus - Google Patents

Abstract

The film to be processed 9 is supported by the support unit 10 of the film surface treatment apparatus 1. The first processing unit 91 brings the first gas g1 containing a polymerizable monomer into contact with the film 9 to be processed. Next, the second processing unit 92 converts the second gas g2 containing the discharge generated gas into plasma and makes it contact the film 9 to be processed. Next, the 3rd gas g3 containing a polymerizable monomer is made to contact the to-be-processed film 9 by the 3rd process part 93. FIG. Next, the fourth processing unit 94 converts the fourth gas g4 containing the discharge generated gas into plasma and contacts the film 9 to be processed. The third gas g3 or the fourth gas g4 further contains an additive component. The additive component is an oxygen gas, a hydrogen gas, a saturated hydrocarbon gas, an unsaturated hydrocarbon gas, or a crosslinking accelerator. Thereby, the adhesion durability of the resin film can be improved. [Selection] Figure 1

Description

  The present invention relates to a method and apparatus for surface-treating a resin-treated film, for example, a film surface treatment method and apparatus suitable for treatment for improving the adhesion durability of a protective film for a polarizing plate.

  For example, a polarizing plate is mounted on a liquid crystal display device. The polarizing plate includes a polarizing film and a protective film. Generally, the polarizing film is comprised with the resin film (henceforth a "PVA film") which contains polyvinyl alcohol (PVA) as a main component. The protective film is composed of a resin film (hereinafter referred to as “TAC film”) containing triacetate cellulose (TAC) as a main component. As adhesives for adhering these films, water-based adhesives such as polyvinyl alcohol and polyether are used. The PVA film has good adhesiveness with the adhesive, but the TAC film does not have good adhesiveness. Therefore, in Patent Documents 1 and 2, before forming the thin film of the polymerizable monomer on the surface of the protective film, the atmospheric pressure plasma is irradiated before the bonding step.

JP 2009-25604 A JP 2010-150372 A

  Only the plasma polymerization treatment of the polymerizable monomer has insufficient adhesion durability. In particular, when the plasma polymerized film is a water-soluble polymer such as polyacrylic acid, the adhesive strength is likely to be lowered in a high temperature and high humidity environment.

In order to solve the above problems, the method of the present invention is a film surface treatment method for treating the surface of a resin film to be treated,
A first treatment step of contacting the film to be treated with a first gas containing a vaporized polymerizable monomer;
After the first treatment step or in parallel with the first treatment step, the second gas containing the discharge product gas is turned into plasma (including excitation, activation, radicalization, ionization, etc.) to the film to be treated. A second treatment step to contact,
After the second treatment step, a third treatment step in which a third gas containing a vaporized polymerizable monomer is brought into contact with the film to be treated;
A fourth treatment step after the third treatment step or in parallel with the third treatment step, wherein a fourth gas containing a discharge product gas is converted into plasma and brought into contact with the film to be treated;
The third gas or the fourth gas further contains an additive component, and the additive component is an oxygen gas, a hydrogen gas, a saturated hydrocarbon gas, an unsaturated hydrocarbon gas, or a crosslinking accelerator. It is characterized by.

  By the first treatment step and the second treatment step, a first plasma polymerization film formed by plasma polymerization of the polymerizable monomer in the first gas is formed on the surface of the film to be treated. The third treatment step and the fourth treatment step increase the degree of polymerization of the first plasma polymerization film, and the second plasma polymerization film formed by plasma polymerization of the polymerizable monomer in the third gas is the first plasma polymerization film. It is formed by laminating on the plasma polymerization film. By adding the additive component to the third gas or the fourth gas, it is considered that the second plasma polymerized film is hydrophobized or cross-linked (including high molecular weight). It is considered that the reactivity (adhesiveness) of the plasma polymerized film to the adhesive is improved. Therefore, the water resistance of the plasma polymerized film can be improved. In particular, even if the plasma polymerized film is a water-soluble polymer such as polyacrylic acid, its water resistance can be reliably ensured. As a result, the adhesion durability of the film to be processed can be improved. Here, the adhesion durability refers to the degree to which the adhesion strength does not decrease after the object after bonding is exposed to a high humidity and high temperature wet heat environment.

The device of the present invention is a film surface treatment device for treating the surface of a resin-treated film,
A support part for supporting the film to be processed;
A first processing unit for performing a process of bringing the first gas containing the vaporized polymerizable monomer into contact with the film to be processed;
A second processing unit for performing a process of converting the second gas containing the discharge generated gas into plasma and bringing it into contact with the film to be processed;
A third processing unit for performing a process of bringing the third gas containing the vaporized polymerizable monomer into contact with the film to be processed;
A fourth processing unit for performing a process of converting the fourth gas containing the discharge generated gas into plasma and bringing it into contact with the film to be processed;
Conveying means for conveying the film to be processed in the order of the first processing unit, the second processing unit, the third processing unit, and the fourth processing unit;
The third gas or the fourth gas further contains an additive component, and the additive component is an oxygen gas, a hydrogen gas, a saturated hydrocarbon gas, an unsaturated hydrocarbon gas, or a crosslinking accelerator. It is characterized by.

  The first treatment unit can form a first condensed layer made of a polymerizable monomer in the first gas on the surface of the film to be treated. Then, a to-be-processed film can be conveyed to a 2nd process part by a conveyance means, the said 1st condensed layer can be plasma-polymerized by a 2nd process part, and a 1st plasma polymerization film | membrane can be formed in the surface of a to-be-processed film. Then, a to-be-processed film is conveyed to a 3rd process part by a conveyance means, and the 2nd condensed layer which consists of a polymerizable monomer in 3rd gas is made on the surface of a to-be-processed film by a 3rd process part. Or the 2nd condensed layer which consists of a mixture of the polymerizable monomer and additional component in 3rd gas can be formed. Thereafter, the film to be processed is transported to the fourth processing section by the transporting means, and the degree of polymerization of the first plasma polymerized film is increased by the fourth processing section, and the second condensed layer is plasma-polymerized to generate the second plasma. A polymerized film can be laminated on the first plasma polymerized film. It is considered that the second plasma polymerized film is hydrophobized or cross-linked by adding the additive component to the third gas or the fourth gas, and depending on the additive component, the plasma polymerized film adhesive It is thought that the reactivity (adhesiveness) with respect to is improved. Therefore, the water resistance of the plasma polymerized film can be improved. In particular, even if the plasma polymerized film is a water-soluble polymer such as polyacrylic acid, its water resistance can be reliably ensured. As a result, the adhesion durability of the film to be processed can be improved.

  The support portion includes metal first, second, and third rolls arranged in parallel to each other, the film to be treated is wound around these rolls, and the first roll is rotated by the rotation of these rolls. The second roll and the third roll are preferably sent in this order. It is preferable that the first processing unit includes a first nozzle that blows out the first gas while facing a peripheral surface of the first roll. The second processing unit includes a second nozzle that blows the second gas into a gap between the first roll and the second roll, and the first and second rolls are in the vicinity of atmospheric pressure between each other. It is preferable to configure a pair of electrodes that generate a discharge. It is preferable that the third processing unit includes a third nozzle that blows out the third gas while facing a peripheral surface of the second roll. The fourth processing unit includes a fourth nozzle that blows the fourth gas into a gap between the second roll and the third roll, and the second and third rolls are in the vicinity of atmospheric pressure between each other. It is preferable to configure a pair of electrodes that generate a discharge.

  Thus, the first gas is sprayed from the first nozzle to the film to be processed on the peripheral surface of the first roll while the film to be processed is fed in the order of the first roll, the second roll, and the third roll. The film to be processed can be irradiated with plasma by converting the second gas into a gap between the two rolls. Subsequently, the third gas is sprayed from the third nozzle onto the film to be processed on the peripheral surface of the second roll, and then the fourth gas can be converted into plasma at the gap between the second and third rolls to be irradiated onto the film to be processed. The three rolls also serve as the transport unit. The first roll is provided as an image forming unit that defines the first processing space of the first processing unit. The first roll and the second roll are provided as a defining unit that defines a second processing space of the pair of electrodes that convert the second gas into plasma and the second processing unit. The second roll is provided as an image forming unit that defines the third processing space of the third processing unit. The second roll and the third roll are provided as a defining section that defines a fourth processing space of the fourth processing section and the pair of electrodes that convert the fourth gas into plasma.

The surface treatment of the present invention is preferably performed under atmospheric pressure. In particular, the plasma treatment in the second treatment step and the fourth treatment step is preferably performed near atmospheric pressure. Here, the vicinity of the atmospheric pressure refers to a range of 1.013 × 10 ^{4 to} 50.663 × 10 ⁴ Pa, and considering the ease of pressure adjustment and the simplification of the apparatus configuration, 1.333 × 10 ⁴ to 10.664 × 10 ⁴ Pa is preferable, and 9.331 × 10 ^{4 to} 10.9797 × 10 ⁴ Pa is more preferable.

  The film to be treated is preferably a hard-to-adhere optical resin film. The present invention is suitable for improving the adhesiveness and adhesion durability of a hard-to-adhere optical resin film when adhering the hard-to-adhere optical resin film to an easily-adhesive optical resin film. 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. The film to be treated is more preferably a TAC film.

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

The polymerizable monomer of the first gas and the polymerizable monomer of the third gas are preferably the same polymerizable monomer, but they may be different from each other.
Examples of the polymerizable monomers of the first and third gases 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.
When the film to be treated is an olefin monomer polymer film such as COP, COC, PP, and PE, the polymerizable monomer may be a water-soluble monomer and an olefin monomer. Examples of the water-soluble monomer include acetaldehyde, vinyl alcohol, acrylic acid (AA), methacrylic acid, styrene sulfonic acid, acrylamide, methacrylamide, N, N-dimethylaminopropylacrylamide, N, N-dimethylamide and the like. Examples of the olefin monomer include 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-cyclopentene, 1-cyclohexene, 1-cycloheptene, 1-cyclooctene, cyclopentadiene, dicyclopentadiene (DCPD). Etc.

Of the polymerizable monomers of the first and third gases, it is more preferable that the polymerizable monomer of the first gas has a high affinity with the film to be treated when plasma polymerization is performed. Examples of such a monomer include monomers having an ethylenically unsaturated double bond and a carboxyl group. Specifically, acrylic acid (CH ₂ ═CHCOOH), methacrylic acid (CH ₂ ═C (CH ₃₎ ) COOH). The polymerizable monomer for the first gas and the polymerizable monomer for the third gas are more preferably acrylic acid or methacrylic acid, and even more preferably acrylic acid. Thereby, the affinity with the film to be processed can be expressed when plasma polymerization is performed. Therefore, the adhesion of the film to be processed, and thus the adhesion durability can be reliably increased.

  Preferably, the first gas and the second gas do not contain the additive component. Thereby, when the polymerizable monomer in the first gas undergoes plasma polymerization, affinity with the film to be processed can be surely expressed. As a result, the adhesiveness and adhesion durability of a to-be-processed film can be improved reliably.

  The additive component is a compound different from the polymerizable monomer, and exhibits an action such as hydrophobization, crosslinking, or promoting reactivity with the adhesive of the plasma monomer of the polymerizable monomer. preferable.

  Of the third and fourth gases, the fourth gas preferably contains oxygen gas, hydrogen gas, saturated hydrocarbon gas, or unsaturated hydrocarbon gas as the additive component. These additive components are considered to induce actions such as hydrophobization, crosslinking, or promotion of reactivity with the adhesive of the polymerizable monomer in the fourth treatment step.

When the fourth gas contains oxygen (O ₂ ) as the additive component, the volume concentration of oxygen in the fourth gas is preferably 500 ppm to 3000 ppm. By setting the oxygen concentration to 500 ppm or more, desired adhesion durability can be secured. By setting the oxygen concentration to 3000 ppm or less, it is possible to prevent the polymerization reaction of the polymerizable monomer from being inhibited.

When the fourth gas contains hydrogen (H ₂ ) as the additive component, the volume concentration of hydrogen in the fourth gas is preferably 500 ppm to 10,000 ppm. By making the hydrogen concentration 500 ppm or more, desired adhesion durability can be secured. If the hydrogen concentration exceeds 8000 ppm to 10000 ppm, the degree of improvement in adhesion durability is saturated. By setting the hydrogen concentration to 10,000 ppm or less, desired adhesion durability can be obtained and the amount of hydrogen gas used can be saved.

  Examples of the saturated hydrocarbon include methane, ethane, propane, and butane. Examples of the unsaturated hydrocarbon include ethylene and acetylene. The fourth gas may contain methane, ethylene, or acetylene as the additional component. Unsaturated hydrocarbons such as acetylene are considered to contribute particularly to the crosslinking of the plasma polymer.

  When the additive component is a crosslinking accelerator, the additive component (crosslinking accelerator) is a compound different from the polymerizable monomer in the first gas and the polymerizable monomer in the third gas. Examples of the crosslinking accelerator include diallyl compounds, diamine compounds, glycidyl compounds, and hydroxy compounds. These compounds are known as crosslinking accelerators, and are considered to contribute particularly to crosslinking of the plasma polymer and promotion of reactivity with the adhesive. The crosslinking accelerator as the additive component is preferably contained in the third gas.

  Examples of diallyl compounds include diallylamine, diallyl maleate, and allyl methacrylate. Examples of the diamine compound include ethylenediamine. Examples of the glycidyl compound include allyl glycidyl ether and glycidyl methacrylate. Examples of the hydroxy compound include hydroxyethyl acrylate and hydroxyethyl methacrylate.

  The first gas or the third gas may contain a carrier gas that conveys a polymerizable monomer. 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 for vaporizing the polymerizable monomer into the carrier gas, there are an extrusion method in which saturated vapor on the surface of the polymerizable monomer is extruded with the carrier gas, a bubbling method in which the carrier gas is bubbled into the polymerizable monomer solution, and a polymerizable monomer solution. And a heating system for promoting evaporation by heating. An extrusion method and a heating method, or a bubbling method and a heating method may be used in combination. A part of the carrier gas may be introduced into the vaporizer and the remaining part may not be passed through the vaporizer, and the part of the carrier gas and the remaining part may be merged on the downstream side of the vaporizer. The concentration of the polymerizable monomer in the first gas or the third gas can be adjusted by the temperature of the vaporizer and the distribution ratio between the part and the remainder of the carrier gas.

  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.

  When the crosslinking accelerator in the third gas or the fourth gas is in a liquid phase at normal temperature and pressure, the crosslinking accelerator may be vaporized in a carrier gas such as an inert gas. As a method of vaporizing the crosslinking accelerator into the carrier gas, there are an extrusion method in which saturated vapor on the liquid surface of the crosslinking accelerator is extruded with a carrier gas, a bubbling method in which the carrier gas is bubbled into the liquid of the crosslinking accelerator, and a crosslinking accelerator A heating method for heating the liquid to promote evaporation and the like. An extrusion method and a heating method, or a bubbling method and a heating method may be used in combination. A part of the carrier gas may be introduced into the vaporizer and the remaining part may not be passed through the vaporizer, and the part of the carrier gas and the remaining part may be merged on the downstream side of the vaporizer. The concentration of the crosslinking accelerator in the third gas or the fourth gas can be adjusted by the temperature of the vaporizer and the distribution ratio between the part and the remainder of the carrier gas.

When the crosslinking accelerator is contained in the third gas, the liquid phase polymerizable monomer and the liquid phase crosslinking accelerator may be mixed and then the mixed liquid may be vaporized, or the liquid phase polymerizable monomer and the liquid phase After the crosslinking accelerators are vaporized separately from each other, the vaporized polymerizable monomer and the vaporized crosslinking accelerator may be mixed.
When the third gas contains the additive component, the polymerizable monomer of the third gas and the additive component may be mixed on the surface of the film to be treated.
When the fourth gas contains the additive component, the discharge product gas of the fourth gas and the additive component may be mixed on the surface of the film to be treated.

Examples of the discharge product gas of the second gas and the discharge gas of the fourth gas include an inert gas such as nitrogen (N ₂ ) and a rare gas (Ar, Ne, He, etc.). The discharge generated gas may be a mixed gas of a plurality of types of discharge generated gas components. The discharge generated gas of the second gas and the discharge generated gas of the fourth gas may be the same gas or different gases.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive durability of a to-be-processed film can be improved.

It is a side view which shows explanatoryally the film surface treatment apparatus which concerns on 1st Embodiment of this invention. It is a perspective view of the principal part of the said film surface treatment apparatus. The surface treatment process of 1st Embodiment is shown, (a) is sectional drawing of the to-be-processed film after a 1st processing process, (b) is sectional drawing of the to-be-processed film after a 2nd processing process. (C) is sectional drawing of the to-be-processed film after a 3rd process process, (d) is sectional drawing of the to-be-processed film after a 4th process process. It is sectional drawing which shows a part of polarizing plate. It is a side view which shows explanatoryally the film surface treatment apparatus which concerns on 2nd Embodiment of this invention. The surface treatment process of 2nd Embodiment is shown, (a) is sectional drawing of the to-be-processed film after a 1st processing process, (b) is sectional drawing of the to-be-processed film after a 2nd processing process. (C) is sectional drawing of the to-be-processed film after a 3rd process process, (d) is sectional drawing of the to-be-processed film after a 4th process process.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 4 shows the polarizing plate PF. The polarizing plate PF includes a polarizing film 7 and a protective film 9. A polarizing film 7 is sandwiched between two protective films 9. Each protective film 9 and polarizing film 7 are bonded together with an adhesive 8. The polarizing film 7 is composed of a PVA film containing polyvinyl alcohol (PVA) as a main component. As the adhesive 8, a PVA adhesive such as a PVA aqueous solution is used. The PVA adhesive may contain a known additive component that enhances the adhesive strength. The protective film 9 is composed of a TAC film containing triacetate cellulose (TAC) as a main component. The thickness of the film 9 is, for example, about 100 μm.

  An adhesion promoting film 80 is coated on the surface of the TAC film 9 on the adhesive 8 side. The adhesion promoting film 80 has a laminated structure of two plasma polymerization films 81 and 82. The first plasma polymerization film 81 is made of a plasma polymer of acrylic acid (polymerizable monomer) and is in contact with the TAC film 9. The second plasma polymerized film 82 is made of a plasma polymer of acrylic acid and has characteristics such as water resistance and high reactivity with the adhesive 8. The second plasma polymerization film 82 is in contact with the adhesive 8.

  FIG. 1 shows a film surface treatment apparatus 1 for forming an adhesion promoting film 80 on a TAC film 9 (hereinafter referred to as “processed film 9” as appropriate). The film surface treatment apparatus 1 includes a support unit 10, a first processing unit 91, a second processing unit 92, a third processing unit 93, and a fourth processing unit 94. The TAC film 9 to be processed is a continuous film. The film to be processed 9 is supported by the support portion 10. The 1st process part 91 performs the process which makes the to-be-processed film 9 contact the 1st gas g1 (1st process process). The second processing unit 92 converts the second gas g2 into plasma (including excitation, activation, radicalization, ionization, etc.) after the processing of the first processing unit 91 or in parallel with the processing of the first processing unit 91. Then, the film 9 is brought into contact with the film 9 (second processing step). Thereby, the first plasma polymerization film 81 is formed. The 3rd process part 93 makes the 3rd gas g3 contact the to-be-processed film 9 after the process of the 2nd process part 92 (3rd process process). The 4th process part 94 makes the 4th gas g4 into plasma after the process of the 3rd process part 93, or the process of the 3rd process part 93, and contacts the to-be-processed film 9 (4th process process). Thereby, the second plasma polymerization film 82 is formed. The details will be described below.

  As shown in FIGS. 1 and 2, the support portion 10 includes three main rolls 11, 12, and 13 and guide rolls 16 and 17. The main rolls 11 to 13 are cylindrical bodies having the same diameter and the same axial length. At least the outer peripheral portions of the rolls 11 to 13 are made of metal, and a solid dielectric layer is coated on the outer peripheral surface of the outer peripheral portion made of the metal. The axes of the rolls 11, 12, 13 are directed in the horizontal direction (hereinafter referred to as “processing width direction”) orthogonal to the paper surface of FIG. 1. Three rolls 11, 12, and 13 are arranged in this order and in parallel. In FIG. 1, the thickness of the gap 92a between the left first roll 11 and the center second roll 12 and the gap 92a, 94a between the center second roll 12 and the right third roll 13 are the same as each other. equal. The thickness of the narrowest part of the gaps 92a and 94a is, for example, about 1 mm to several mm.

  The rolls 11 to 13 also serve as plasma discharge generation electrodes of the film surface treatment apparatus 1. Although illustration is omitted, a power source is connected to the central roll 12, and the left and right rolls 11 and 13 are electrically grounded. Instead of this, a power source may be connected to each of the left and right rolls 11 and 13, and the central roll 12 may be electrically grounded. The power source outputs, for example, pulsed high frequency power. By this power supply, plasma discharge is generated between the left roll 11 and the central roll 12 under a pressure near atmospheric pressure, and the gap 92a becomes a discharge space near atmospheric pressure. Further, by the power supply, a plasma discharge is generated between the central roll 12 and the right roll 13 under a pressure near atmospheric pressure, and the gap 94a becomes a discharge space near atmospheric pressure.

  A plurality of (two in the figure) front guide rolls 16 and 16 are arranged below the rolls 11 and 12. Below the rolls 12 and 13, a plurality (two in the figure) of rear guide rolls 17 and 17 are arranged.

  A continuous sheet-like processed film 9 is supported by the support unit 10 with the width direction directed in the processing width direction (the direction perpendicular to the plane of FIG. 1). The to-be-processed film 9 is wound around the upper peripheral surface of the three rolls 11, 12, and 13 about half a circumference. The upper peripheral surface of each of the rolls 11, 12, and 13 and the approximately half-peripheral portion including the portions that define the gaps 92 a and 94 a are covered with the film 9 to be processed.

  The film 9 to be processed between the rolls 11 and 12 is hung down from the gap 92 a and is wound around the guide rolls 16 and 16. Thereby, the to-be-processed film 9 between the gap 92a and the guide rolls 16 and 16 forms the folding | turning part 9a. The folded portion 9a has a triangular shape when viewed from the processing width direction.

  The film 9 to be processed between the rolls 12 and 13 is hung downward from the gap 94 a and is wound around the guide rolls 17 and 17. Thereby, the to-be-processed film 9 between the gap 94a and the guide rolls 17 and 17 forms the folding | turning part 9b. The folded portion 9b has a triangular shape when viewed from the processing width direction.

  Although not shown, a rotating mechanism is connected to each of the rolls 11, 12, and 13. The rotation mechanism includes a drive unit such as a motor and a transmission unit that transmits the driving force of the drive unit to the shafts of the rolls 11, 12, and 13. The transmission means is constituted by, for example, a belt / pulley mechanism or a gear train. 1, the rolls 11, 12, 13 are rotated around their own axes and in the same direction (clockwise in FIG. 1) in synchronism with each other by the rotating mechanism. The Thereby, the to-be-processed film 9 is conveyed in a substantially right direction in order of the 1st roll 11, the 2nd roll 12, and the 3rd roll 13. FIG. The support unit 10 also serves as a conveying means for the film 9 to be processed.

  Each roll 11, 12, 13 is provided with temperature control means (not shown). The temperature control means is constituted by a temperature control path formed in the rolls 11, 12, and 13, for example. The temperature of the rolls 11, 12, and 13 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 rolls 11, 12, 13 can be temperature-controlled. The set temperatures of the rolls 11, 12, and 13 are preferably lower than the condensation temperature of the polymerizable monomer.

The first processing unit 91 includes a first gas g 1 supply unit 21 and a first nozzle 31. The first gas g1 contains a polymerizable monomer and a carrier gas. Acrylic acid AA is used as the polymerizable monomer. Nitrogen (N ₂ ) is used as the carrier gas.

  Although detailed illustration is omitted, the first gas supply unit 21 includes a vaporizer. In the vaporizer, liquid acrylic acid is vaporized into the carrier gas. The vaporization may be a bubbling method or an extrusion method. The first gas g1 is generated by mixing the vaporized acrylic acid and the carrier gas. The first gas g1 does not contain an additive component described later.

  The first gas supply unit 21 is connected to the first nozzle 31 through a gas path 21c. The first nozzle 31 is disposed above the first roll 11. The first nozzle 31 extends long in the processing width direction and has a certain width in the circumferential direction of the first roll 11 (left and right in FIG. 1). An outlet is provided on the lower surface of the first nozzle 31. The outlets are formed so as to be distributed over a wide range (the processing width direction and the roll circumferential direction) of the lower surface of the first nozzle 31. The blowing surface (lower surface) of the first nozzle 31 faces the film 9 to be processed on the first roll 11. The first gas g1 from the first gas supply unit 21 is supplied to the first nozzle 31 via the first gas supply line 21c, and is made uniform by a rectification unit (not shown) in the first nozzle 31. The air is blown out from the outlet of the first nozzle 31. The blow-out flow of the first gas g1 is a flow that is uniformly distributed in the processing width direction.

  The gas passage 21c and the first nozzle 31 are provided with temperature adjusting means (not shown). The temperature adjusting means of the gas passage 21c is constituted by a ribbon heater or the like. The temperature adjustment means of the first nozzle 31 is configured by a temperature adjustment path through which temperature adjustment water passes. The set temperatures of the gas passage 21c and the first nozzle 31 are higher than the condensation temperature of acrylic acid. Thereby, it is possible to prevent the acrylic acid from condensing in the gas passage 21 c or the nozzle 31 before being blown out from the nozzle 31.

  A shielding member 41 is provided at the bottom of the first nozzle 31. The shielding member 41 has an arcuate cross section along the circumferential direction of the first roll 11, and has a curved plate shape extending substantially the same length as the roll 11 in the processing width direction. Both ends of the shielding member 41 in the arc direction (left and right in FIG. 1) extend in the circumferential direction of the first roll 11 from the first nozzle 31. The circumferential length of the shielding member 41 in the arc direction (left and right in FIG. 1) is, for example, about 240 to 300 mm. In FIG. 1, the left end of the shielding member 41 is released. In FIG. 1, the right end of the shielding member 41 is in contact with or close to the closing member 51 described later.

  A first processing space 91 a is defined between the shielding member 41 and the first roll 11. The first roll 11 is provided as a defining unit of the first processing space 91 a in the first processing unit 91. The first processing space 91 a is a space having an arcuate cross section along the upper peripheral surface of the first roll 11. The outlet on the lower surface of the first nozzle 31 passes through the shielding member 41 and communicates with the first processing space 91a. The first processing space 91 a is extended by the shielding member 41 to both sides in the circumferential direction of the first roll 11 rather than the first nozzle 31. In FIG. 1, the left end portion of the first processing space 91 a is connected to the external space on the left side of the roll 11 (the side opposite to the roll 12 side). In FIG. 1, the right end portion of the first processing space 91 a is connected to a gap between a closing member 51 and a roll 11 which will be described later.

  The first processing space 91a is narrow at the central portion in the arc direction (left and right in FIG. 1), and is slightly wider toward both ends in the arc direction. The thickness of the first processing space 91a is preferably about 1 mm to 10 mm. The thickness of the narrowest portion of the first processing space 91a is preferably about 1 mm, for example. The thickness of the widest portion of the first processing space 91a is preferably about 10 mm, for example. The thickness of the first processing space 91a may be constant throughout. The shielding member 41 may be separated into an upstream portion and a downstream portion in the rotation direction of the first roll 11 with the first nozzle 31 in between, and the bottom surface of the first nozzle 31 is the first processing space. You may face 91a directly.

The second processing unit 92 includes a second gas g <b> 2 supply unit 22 and a second nozzle 32. The second gas g2 contains a discharge product gas. Nitrogen (N ₂ ) is used as the discharge product gas. The second gas does not contain an additive component described later.

A second nozzle 32 is connected to the second gas supply unit 22. The second nozzle 32 is provided inside the triangular folded portion 9 a of the film 9 to be processed. The second nozzle 32 extends long in the processing width direction, and a cross section perpendicular to the extending direction tapers upward. The blowout port at the upper end (tip) of the second nozzle 32 faces the inter-roll gap 92a. The lower end portion of the gap 92 a is blocked to some extent by the second nozzle 32. The second gas g2 from the second gas supply unit 22 is made uniform in the processing width direction by a rectifying unit (not shown) in the second nozzle 32, and then from the outlet of the second nozzle 32 to the gap 92a. Is blown out. The blow-out flow of the second gas g2 is a flow that is uniformly distributed in the processing width direction.
The gap 92a constitutes a second processing space of the second processing unit 92. The rolls 11 and 12 are provided as a definition unit of the second processing space 92 a in the second processing unit 92.

  In the second nozzle 32, a temperature control path (second gas temperature control means) (not shown) is provided. A temperature control medium such as water is passed through the temperature control path in the second nozzle 32. As a result, the temperature of the second nozzle 32 can be adjusted, and the temperature of the second gas g2 can be adjusted. The set temperature of the second nozzle 32 is lower than the set temperature of the first nozzle 31, and is preferably lower than the condensation temperature of acrylic acid (polymerizable monomer).

  The closing member 51 is disposed between the rolls 11 and 12 above the second processing space 92a. The blocking member 51 is opposed to the second nozzle 32 with the second processing space 92a interposed therebetween. The blocking member 51 extends long in the processing width direction, and a cross section perpendicular to the extending direction tapers downward. The lower end (front end) of the closing member 51 faces the second processing space 92a. The upper end portion of the second processing space 92 a is blocked to some extent by the closing member 51. The first processing space 91a and the second processing space 92a communicate with each other through a gap between the closing member 51 and the first roll 11. A nozzle having the same structure as that of the second nozzle 32 may be used as the closing member 51, and this may be installed upside down with respect to the second nozzle 32 so that the second gas g2 is blown from the nozzle 51. May be.

The third processing unit 93 includes a third gas supply unit 23 and a third nozzle 33. The third gas supply unit 23 supplies the third gas g3 to the third nozzle 33. The third gas g3 is composed of the same gas as the first gas g1. That is, the third gas g3 contains a polymerizable monomer and a carrier gas. Acrylic acid AA is used as the polymerizable monomer. Nitrogen (N ₂ ) is used as the carrier gas.

  Although detailed illustration is omitted, the third gas supply unit 23 includes a vaporizer. In the vaporizer, liquid acrylic acid is vaporized into the carrier gas. The vaporization may be a bubbling method or an extrusion method. By mixing the vaporized acrylic acid and the carrier gas, the third gas g3 is generated. The first gas supply unit 21 and the third gas supply unit 23 may be configured by a common acrylic acid supply source.

  The third gas supply unit 23 is connected to the third nozzle 33 through the gas path 23c. The third nozzle 33 is disposed above the second roll 12. The third nozzle 33 extends in the processing width direction and has a certain width in the circumferential direction of the second roll 12 (left and right in FIG. 1). An outlet is provided on the lower surface of the third nozzle 33. The outlets are formed so as to be distributed over a wide range (the processing width direction and the roll circumferential direction) of the lower surface of the third nozzle 33. The blowing surface (lower surface) of the third nozzle 33 faces the film 9 to be processed on the second roll 12. The third gas g3 from the third gas supply unit 23 is supplied to the third nozzle 33 via the third gas supply line 23c, and is made uniform by a rectification unit (not shown) in the third nozzle 33. The air is blown out from the outlet of the third nozzle 33. The blow-out flow of the third gas g3 is a flow that is uniformly distributed in the processing width direction.

  The gas passage 23c and the third nozzle 33 are provided with temperature adjusting means (not shown). The temperature adjusting means of the gas passage 23c is constituted by a ribbon heater or the like. The temperature adjustment means of the third nozzle 33 is configured by a temperature adjustment path through which temperature adjustment water passes. The set temperatures of the gas passage 23c and the third nozzle 33 are higher than the condensation temperature of acrylic acid. Accordingly, it is possible to prevent the acrylic acid from condensing in the gas path 23 c or the nozzle 31 before being blown out from the nozzle 33.

  A shielding member 43 is provided at the bottom of the third nozzle 33. The shielding member 43 has an arc-shaped cross section along the circumferential direction of the second roll 12 and has a curved plate shape extending in the processing width direction for substantially the same length as the roll 12. Both end portions of the shielding member 43 in the arc direction (left and right in FIG. 1) extend beyond the third nozzle 33 in the circumferential direction of the second roll 12. The circumferential length of the shielding member 43 in the arc direction (left and right in FIG. 1) is, for example, about 240 to 300 mm. The upstream end (left in FIG. 1) of the shielding member 43 in the rotation direction of the roll 12 is in contact with or close to the side of the closing member 51. The downstream end (right in FIG. 1) of the shielding member 43 in the rotation direction of the roll 12 is in contact with or close to the closing member 52 described later.

  A third processing space 93 a is defined between the shielding member 43 and the second roll 12. The second roll 12 is provided as a defining part of the third processing space 93 a in the third processing unit 93. The third processing space 93 a is a space having an arcuate cross section along the upper peripheral surface of the second roll 12. The outlet on the lower surface of the third nozzle 33 penetrates the shielding member 43 and communicates with the third processing space 93a. By the shielding member 43, the third processing space 93 a is extended from the third nozzle 33 to both sides in the circumferential direction of the second roll 12. In FIG. 1, the left end portion of the third processing space 93 a is connected to the second processing space 92 a through a gap between the closing member 51 and the roll 12. In FIG. 1, the right end of the third processing space 93 a is continuous with a gap between the closing member 52 and the roll 12 described later.

  The third processing space 93a is narrow at the central portion in the arc direction (left and right in FIG. 1), and is slightly wider toward both ends in the arc direction. The thickness of the third processing space 93a is preferably about 1 mm to 10 mm. The thickness of the narrowest portion of the third processing space 93a is preferably about 1 mm, for example. The thickness of the widest portion of the third processing space 93a is preferably about 10 mm, for example. The thickness of the third processing space 93a may be constant throughout. The shielding member 43 may be separated into an upstream portion and a downstream portion in the rotation direction of the second roll 12 with the third nozzle 33 interposed therebetween, and the bottom surface of the third nozzle 33 is the third processing space. You may face 93a directly.

  The fourth processing unit 94 includes a fourth gas g4 supply unit 24 and a fourth nozzle 34. The fourth gas g4 contains a discharge product gas and an additive component. The fourth gas supply unit 24 includes a discharge generation gas supply unit 24a and an additive component supply unit 24b.

Nitrogen (N ₂ ) is used as the discharge product gas of the fourth gas g4. The additive component is oxygen (O ₂ ), hydrogen (H ₂ ), saturated hydrocarbon gas (C _n H _{2n + 2} (n ≧ 1)), or unsaturated hydrocarbon gas (C _n H _2n−2 (n ≧ 2) and C _n H _2n (n ≧ 2)). In the fourth gas supply unit 24, an additive component is mixed with the discharge generated gas. As a result, the fourth gas g4 is generated.

When the additive gas is oxygen, the oxygen concentration in the fourth gas g4 is preferably 500 ppm to 3000 ppm (volume concentration). When the additive gas is hydrogen, the hydrogen concentration in the fourth gas g4 is preferably 500 ppm to 10000 ppm (volume concentration). Examples of the saturated hydrocarbon gas include methane (CH ₄ ), ethane (C ₂ H ₆ ), propane (C ₃ H ₈ ), butane (C ₄ H ₁₀ ), and the like. Examples of the unsaturated hydrocarbon gas include ethylene (C ₂ H ₄ ) and acetylene (C ₂ H ₂ ). The concentration of the saturated hydrocarbon gas or the unsaturated hydrocarbon gas in the fourth gas g4 is preferably 100 ppm to 10000 ppm (volume concentration).

A fourth nozzle 34 is connected to the fourth gas supply unit 24. The fourth nozzle 34 is provided inside the triangular folded portion 9 b of the film 9 to be processed. The fourth nozzle 34 extends long in the processing width direction, and a cross section perpendicular to the extending direction tapers upward. An outlet at the upper end (tip) of the fourth nozzle 34 faces the inter-roll gap 94a. The lower end of the gap 94a is blocked to some extent by the fourth nozzle 34. The fourth gas g2 from the fourth gas supply unit 24 is made uniform in the processing width direction by a rectification unit (not shown) in the fourth nozzle 34, and then from the outlet of the fourth nozzle 34 to the gap 94a. Is blown out. The blow-out flow of the fourth gas g4 is a flow that is uniformly distributed in the processing width direction.
The gap 94 a constitutes a fourth processing space of the fourth processing unit 94. The rolls 12 and 13 are provided as a defining unit of the fourth processing space 94a in the fourth processing unit 94.

  A temperature control path (fourth gas temperature control means) (not shown) is provided in the fourth nozzle 34. A temperature control medium such as water is passed through the temperature control path in the fourth nozzle 34. As a result, the temperature of the fourth nozzle 34 can be adjusted, and the temperature of the fourth gas g4 can be adjusted. The set temperature of the fourth nozzle 34 is lower than the set temperature of the third nozzle 33, and preferably lower than the condensation temperature of acrylic acid (polymerizable monomer).

  A closing member 52 is disposed between the rolls 12 and 13 above the fourth processing space 94a. The closing member 52 faces the fourth nozzle 34 with the fourth processing space 94a interposed therebetween. The closing member 52 extends long in the processing width direction, and a cross section perpendicular to the extending direction tapers downward. The lower end (front end) of the closing member 52 faces the fourth processing space 94a. The upper end portion of the fourth processing space 94a is blocked to some extent by the closing member 52. The third processing space 93a and the fourth processing space 94a communicate with each other through a gap between the closing member 52 and the second roll 12. The fourth processing space 94 a is connected to the external space above the third roll 13 through a gap between the closing member 52 and the third roll 13. A nozzle having the same structure as that of the fourth nozzle 34 may be used as the closing member 52, and this may be installed upside down with respect to the fourth nozzle 34 so that the second gas g2 is blown from the nozzle 52. May be.

A method for surface-treating the film 9 to be treated by the film surface treatment apparatus 1 having the above-described configuration, and a method for producing a polarizing plate will be described.
[Support process, transport process]
The to-be-processed film 9 which consists of a TAC film is hung around the main rolls 11-13 of the support part 10, and the guide rolls 16 and 17. FIG.
The rolls 11 to 13 are rotated clockwise in FIG. 1, and the film 9 to be processed is conveyed in the order of the first roll 11, the second roll 12, and the third roll 13 in a substantially right direction in FIG. 1.

[First processing step]
In the first processing unit 91, the first gas g <b> 1 is supplied from the supply unit 21 to the nozzle 31. The first gas g1 is blown out from the nozzle 31 to the first processing space 91a. The 1st gas g1 contacts the surface of the to-be-processed film 9 in the 1st process space 91a. As a result, as shown in FIG. 3A, the acrylic acid monomer in the first gas g1 condenses and adheres to the film to be processed 9, and the surface of the film to be processed 9 is made of the acrylic acid monomer. A condensed layer 83 is formed. A majority of the first gas g1 in the first processing space 91a flows toward the second processing space 92a along the transport direction of the film 9 to be processed. The shielding member 41 can suppress or prevent the first gas g1 from leaking to the outside, and can secure the amount of acrylic acid attached to the film 9 to be processed.

[Second treatment step]
As the first roll 11 rotates, the film to be processed 9 that has undergone the first processing step is conveyed to the second processing space 92a. In the second processing unit 92, the second gas g <b> 2 is supplied from the supply unit 22 to the nozzle 32. The second gas g2 is blown out from the nozzle 32 to the second processing space 92a. At the same time, power is supplied to the roll 12 to generate a discharge in the vicinity of the atmospheric pressure in the second processing space 92a, and the discharge generated gas nitrogen is turned into plasma. This nitrogen plasma comes into contact with the surface of the film 9 to be processed in the second processing space 92a. As a result, as shown in FIG. 3B, the acrylic acid monomer of the first condensing layer 83 undergoes plasma polymerization, and a first plasma polymerization film 81 made of polyacrylic acid is formed on the surface of the film 9 to be processed. . Polyacrylic acid has good affinity with TAC, and sufficiently reacts with and adheres to the surface molecules of TAC. In particular, since the first gas g1 and the second gas g2 do not contain the additive component, the purity of the polyacrylic acid in the first plasma polymerization film 81 can be increased, and the affinity can be sufficiently secured. The film to be processed 9 is folded back by the guide roll 16 so as to reciprocate in the second processing space 92 a and processed twice by the second processing unit 92.

[Third treatment step]
The processed film 9 after reciprocating in the second processing space 92 a is conveyed along the second roll 12 to the third processing space 93 a. In the third processing unit 93, the third gas g <b> 3 is supplied from the third gas supply unit 23 to the third nozzle 33. The third gas g3 is blown out from the third nozzle 33 to the third processing space 93a. The third gas g3 contacts the surface of the film 9 to be processed in the third processing space 93a. As shown in FIG. 3C, the acrylic acid monomer in the third gas g3 condenses and adheres to the film 9 to be processed, and a second plasma made of acrylic acid monomer is further formed on the first plasma polymerization film 81. The condensed layer 84 is formed. A majority of the third gas g3 in the third processing space 93a flows toward the fourth processing space 94a along the transport direction of the film 9 to be processed. It is possible to suppress or prevent the third gas g3 from leaking to the outside by the shielding member 43, and to secure an adhesion amount of acrylic acid.

[Fourth treatment step]
As the second roll 12 rotates, the film to be processed 9 that has undergone the third processing step is conveyed to the fourth processing space 94a. In the fourth processing unit 94, the fourth gas g <b> 4 is supplied from the fourth gas supply unit 24 to the fourth nozzle 34. The fourth gas g4 is blown out from the fourth nozzle 34 to the fourth processing space 94a. In the fourth processing space 94a, a discharge near atmospheric pressure is generated by the power supply. As a result, the nitrogen and additive components of the fourth gas g4 are converted into plasma, and the plasmaized gas comes into contact with the surface of the film 9 to be processed in the fourth processing space 94a. Thereby, the polymerization degree of the first plasma polymerization film 81 can be increased. In addition, as shown in FIG. 3D, the acrylic acid monomer of the second condensing layer 84 undergoes plasma polymerization, and a second plasma polymerization film 82 made of polyacrylic acid is laminated on the first plasma polymerization film 81, An adhesion promoting film 80 is formed. At this time, it is considered that the added component is decomposed and bonded to polyacrylic acid, thereby imparting hydrophobicity to the second plasma polymerized film 82 or increasing the degree of crosslinking of the second plasma polymerized film 82. As a result, the water resistance of the adhesion promoting film 80 can be improved. The film to be processed 9 is folded back by the guide roll 17 so as to reciprocate in the fourth processing space 94 a and processed twice by the fourth processing unit 94. The processed film 9 after reciprocating in the fourth processing space 94 a is sent along the third roll 13 and is carried out of the support portion 10.

  As shown in FIG. 4, the film to be processed 9 after the surface treatment by the film surface treatment apparatus 1 is adhered to the PVA film 7 through the PVA adhesive 8 to produce a polarizing plate PF. Since the adhesion promoting film 80 is formed on the surface of the film 9 to be processed, the adhesive strength between the film 9 to be processed and the PVA adhesive 8 can be increased. In addition, since the second plasma polymerization film 82 of the adhesion promoting film 80 is hydrophobized or highly crosslinked, the water resistance is high. Therefore, the adhesion durability of the polarizing plate can be increased. In addition, since the first plasma polymerization film 81 has high purity of polyacrylic acid, it can sufficiently exhibit affinity with TAC. Therefore, the adhesion between the film to be processed 9 and the adhesion promoting film 80 can be secured. Thereby, the quality of the polarizing plate PF can be improved.

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 configurations as those already described, and the description is simplified.
FIG. 5 shows a second embodiment of the present invention. In the film surface treatment apparatus 1A of the second embodiment, the third gas supply unit 23 of the third processing unit 93 includes an acrylic acid supply unit 23a and an additive component supply unit 23b. The fourth gas supply unit 24 of the fourth processing unit 94 supplies only the discharge generated gas (N ₂ ).

The acrylic acid supply unit 23a is the same as the third gas supply unit 23 of the first embodiment (FIG. 1), and vaporizes liquid acrylic acid into the carrier gas (N ₂ ).

The additive component of the additive component supply unit 23b is composed of a crosslinking accelerator. Examples of the crosslinking accelerator include diallyl compounds, diamine compounds, glycidyl compounds, and hydroxy compounds.
Examples of diallyl compounds include diallylamine, diallyl maleate, and allyl methacrylate.
Examples of the diamine compound include ethylenediamine.
Examples of the glycidyl compound include allyl glycidyl ether and glycidyl methacrylate.
Examples of the hydroxy compound include hydroxyethyl acrylate and hydroxyethyl methacrylate.

The additive component supply unit 23b includes a vaporizer. The additive component is vaporized into the carrier gas by this vaporizer. The vaporization may be an extrusion method or a bubbling method. Nitrogen (N ₂ ) is used as the carrier gas. The third gas supply unit 23 mixes the vaporized additive component with the vaporized acrylic acid. Alternatively, a liquid additive component may be mixed with liquid acrylic acid, and the mixed liquid may be vaporized in a carrier gas. Thereby, the third gas g3 is generated. The third gas g3 includes a vapor of acrylic acid, a vapor of the additive component, and a carrier gas (N ₂ ). The weight ratio of acrylic acid and additive component in the third gas g3 is preferably about (acrylic acid) :( additive component) = 99: 1 to 70:30.

The set temperature of the gas path 23c and the third nozzle 33 is preferably higher than the condensation temperature of acrylic acid and the additive component. Thereby, it is possible to prevent the acrylic acid and the additive component from condensing in the gas path 23 c or the third nozzle 33 before being blown out from the third nozzle 23.
The set temperatures of the rolls 11, 12, and 13 are preferably lower than the condensation temperatures of acrylic acid and additive components.
The set temperature of the fourth nozzle 34 is preferably lower than the condensation temperature of acrylic acid and additive components.

  In the film surface treatment apparatus 1A of the second embodiment, as shown in FIG. 6A, a first condensed layer 83 is formed on the surface of the film 9 to be treated in the first treatment unit 91 (first treatment step), Next, as shown in FIG. 6B, the first condensing layer 83 is plasma polymerized in the second processing section 92 to form a first plasma polymerized film 81 (second processing step). Then, in the 3rd process part 93, the 3rd gas g3 is blown out from the 3rd nozzle 33 to the 3rd process space 93a (3rd process process). As a result, as shown in FIG. 6C, the vaporized component (acrylic acid + added component) in the third gas g3 condenses and adheres to the film 9 to be processed, on the first plasma polymerization film 81. Further, a second condensed layer 86 is formed. The second condensed layer 86 is composed of a mixed liquid of an acrylic acid monomer and an additive component (crosslinking accelerator).

  Subsequently, in the fourth processing unit 94, the fourth gas g4 is blown from the fourth nozzle 34 into the fourth processing space 94a to be converted into plasma, and the second condensing layer 86 is irradiated with nitrogen plasma (fourth processing step). Thereby, the degree of polymerization of the first plasma polymerization film 81 is increased. In addition, as shown in FIG. 6 (d), the acrylic acid monomer in the second condensing layer 86 is plasma polymerized, and a second plasma polymer film 85 made of polyacrylic acid is laminated on the first plasma polymer film 81. At the same time, it is considered that the crosslinking accelerator is copolymerized to crosslink the polyacrylic acid of the second plasma polymerization film 85. Furthermore, it is considered that the reactivity (adhesion) of polyacrylic acid to the adhesive 8 is promoted depending on the type of the crosslinking accelerator.

  As a result, an adhesion promoting film 80 composed of the two polymer films 81 and 85 is formed. When the second plasma polymerization film 85 on the surface layer of the adhesion promoting film 80 has a cross-linked structure, the water resistance of the adhesion promoting film 80 can be increased. Furthermore, depending on the additive component, the adhesive strength between the adhesion promoting film 80 and the adhesive 8 can be increased. As a result, the adhesion durability of the polarizing plate can be improved.

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, oxygen, hydrogen, saturated hydrocarbon gas, or unsaturated hydrocarbon gas may be added to the third gas g3. A crosslinking accelerator may be an additive component of the fourth gas g4.
When the additive component is added to the third gas g3, the polymerizable monomer and the additive component of the third gas g3 may be blown out from different nozzles.
When the additive component is added to the fourth gas g4, the discharge generated gas and the additive component of the fourth gas g4 may be blown from different nozzles.

As a polymerizable monomer of the first gas g1 and the third gas g3, methacrylic acid, itaconic acid, maleic acid or the like may be used instead of acrylic acid. As the carrier gas, a rare gas such as Ar or He may be used instead of N ₂ . As the discharge generation gas, a rare gas such as Ar or He may be used instead of N ₂ .

The first processing step and the second processing step may be performed concurrently. The first gas g1 may be directly introduced into the second processing space 92a from the first nozzle 31 to form plasma. The carrier gas in the first gas g1 may also serve as the discharge generation gas of the second gas g1.
The third processing step and the fourth processing step may be performed concurrently. The third gas g3 may be directly introduced into the fourth processing space 94a from the third nozzle 33 to generate plasma. The carrier gas in the third gas g3 may also serve as the discharge generation gas of the fourth gas g4.

In 1st Embodiment (FIG. 1), the 1st gas supply part 21 and the 3rd gas supply part 23 may be comprised by the common acrylic acid supply part. In 2nd Embodiment (FIG. 5), the 1st gas supply part 21 and the acrylic acid supply part 23a may be comprised by the common acrylic acid supply part.
In the first embodiment (FIG. 1), the carrier source of the first gas supply unit 21, the second gas supply unit 22, the carrier source of the third gas supply unit 23, and the discharge gas supply of the fourth gas supply unit 24 The unit 24a may be configured with a common nitrogen supply source. In the second embodiment (FIG. 5), the carrier source of the first gas supply unit 21, the second gas supply unit 22, the carrier source of the third gas supply unit 23, and the fourth gas supply unit 24 are common. You may be comprised with the nitrogen supply source.

  The main component of the film to be treated 9 is not limited to TAC, but polypropylene (PP), polyethylene (PE), cycloolefin polymer (COP), cycloolefin copolymer (COC), polyethylene terephthalate (PET), polymethacrylic acid Methyl (PMMA), polyimide (PI), etc. may be used.

  The present invention is not limited to the surface treatment of a protective film for a polarizing plate, but can be applied to a treatment for forming a polymer film of a polymerizable monomer on various resin films.

Although an Example is described, this invention is not limited to a following example.
The film 9 was subjected to surface treatment using the film surface treatment apparatus 1 shown in FIG.
The dimensional configuration of the apparatus 1 was as follows.
Axle length in roll width direction of rolls 11, 12, 13: 390 mm
Diameter of rolls 11, 12, 13: 320 mm
Nozzle 31-34 blowing width: 300mm
Circumference of the shielding members 41 and 43 in the arc direction: 275 mm
Thickness of the first processing space 91a: 5 mm (constant) throughout
The thickness of the narrowest part of the second processing space 92a: 1 mm
Thickness of the third treatment space 93a: 5 mm (constant) throughout
The thickness of the narrowest part of the fourth processing space 94a: 1 mm

A TAC film was used as the film 9 to be processed. The width of the TAC film 9 was 325 mm.
The conveyance speed of the TAC film 9 was 30 m / min.
The temperature of the rolls 11-13 and by extension, the temperature of the TAC film 9 were set to 40 ° C.

  The power supplied from the power source to the central roll electrode 12 was 3015 W (450 V, 6.7 A direct current converted to high frequency). Half of this power (1507.5 W) was consumed for plasma discharge between roll electrodes 11 and 12, and the other half (1507.5 W) was consumed for plasma discharge between roll electrodes 12 and 13. The applied voltage between the roll electrodes 11 and 12 and the applied voltage between the roll electrodes 12 and 13 were both 18.1 kV.

[First processing step]
In the first processing unit 91, the first gas g1 was brought into contact with the TAC film 9.
Acrylic acid was used as the polymerizable monomer of the first gas g1, and nitrogen (N ₂ ) was used as the carrier gas.
The temperature of the vaporizer of the first gas supply unit 21 was 140 ° C.
The flow rate of the carrier gas (N ₂ ) of the first gas g1 and the flow rate of the first gas g1 (acrylic acid + N ₂ ) were set to 40 slm. The acrylic acid flow rate in the first gas g1 was 7.5 g / min.
The temperature of the first nozzle 31 and the blowing temperature of the first gas g1 were set to 75 ° C.

[Second treatment step]
Next, in the 2nd process part 92, the 2nd gas g2 was made into plasma and made to contact the TAC film 9. FIG.
Nitrogen (N ₂ ) was used as the second gas g2. The flow rate of the second gas g2 was 20 slm.
The temperature of the second nozzle 32 and hence the temperature of the second gas g2 were set to 40 ° C.

[Third treatment step]
Next, in the 3rd process part 93, the 3rd gas g3 was made to contact the TAC film 9. FIG.
Acrylic acid was used as the polymerizable monomer of the third gas g3, and nitrogen (N ₂ ) was used as the carrier gas.
The temperature of the vaporizer of the 3rd gas supply part 23 was 140 degreeC.
The flow rate of the carrier gas (N ₂ ) of the third gas g3, and hence the flow rate of the third gas g3 (acrylic acid + N ₂ ), was 40 slm. The acrylic acid flow rate in the third gas g3 was 7.5 g / min. The amount of the additive component in the third gas g3 was zero.
The temperature of the third nozzle 33 and the blowing temperature of the third gas g3 were set to 75 ° C.

[Fourth treatment step]
Next, in the 4th process part 94, the 4th gas g4 was made into plasma and was made to contact the TAC film 9. FIG.
Nitrogen (N ₂ ) was used as a discharge product gas of the fourth gas g4, and O ₂ was used as an additive component. The flow rate of N ₂ in the fourth gas g4 was 20 slm. The flow rate of O ₂ in the fourth gas g4 was 20 sccm. The concentration of O ₂ in the fourth gas g4 was 1000 ppm. The temperature of the fourth nozzle 34 and hence the temperature of the fourth gas g4 was set to 40 ° C.

Adhesive 8 was applied to the surface to be treated of the TAC film 9 after the surface treatment, and bonded to the PVA film 7. As the adhesive 8, 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 carboxymethyl cellulose 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 7 with the same adhesive as described above. Thus, a plurality of polarizing plate samples having a three-layer structure were produced. The width of the polarizing plate sample was 25 mm.

[Initial bond strength]
After the adhesive 8 was cured, the adhesive strength between the TAC film 9 to be treated and the PVA film 7 (referred to as “initial adhesive strength”) was measured for a polarizing plate sample that had not undergone the wet heat treatment described later. The measuring method was based on the floating roller method (JIS K6854). The result was 9.6 N / 25 mm on average of five measurements.

[Durable adhesive strength]
The remaining polarizing plate sample was subjected to wet heat treatment after the adhesive 8 was cured. The inside of the wet heat treatment tank was set to a high temperature and high humidity environment of 60 ° C. and 96% RH, and the polarizing plate sample was left in this wet heat treatment tank for 1 hour. Thereafter, the polarizing plate sample was taken out of the wet heat treatment tank and cooled at room temperature for 15 minutes. Then, the adhesive strength between the TAC film 9 to be treated and the PVA film 7 (referred to as “durable adhesive strength”) was measured by the same floating roller method (JIS K6854) as the initial adhesive strength. The result was 9.1 N / 25 mm on average of the five measurements. Therefore, it was confirmed that the adhesive strength can be maintained even when exposed to a humid heat environment.

Further, the TAC film was processed with the O ₂ concentration in the fourth gas g4 different from the above in the fourth processing step, and the durable adhesive strength was measured for the polarizing plate sample using the TAC film. When the O ₂ concentration was less than 500 ppm, the durable adhesive strength was lowered and the desired effect could not be obtained. When the O ₂ concentration exceeded 3000 ppm, not only the durable adhesive strength but also the initial adhesive strength decreased. If the O ₂ concentration exceeds 3000 ppm, it is considered that the polymerization reaction itself of acrylic acid is inhibited.

In Example 2, in the fourth process step, the additive component in the fourth gas g4 and _{H 2,} and the flow rate 40 sccm. The H ₂ concentration in the fourth gas g4 was 2000 ppm. Other processing conditions were the same as in Example 1. The procedure for preparing the polarizing plate sample after the surface treatment and the procedure for measuring the initial adhesive strength and the durable adhesive strength were also the same as in Example 1. The initial adhesive strength was 9.8 N / 25 mm, and the durable adhesive strength was 7.2 N / 25 mm. Therefore, it was confirmed that the adhesive strength can be maintained even when exposed to a humid heat environment.

In Example 3, in the fourth process step, the additive component in the fourth gas g4 and _{H 2,} and the flow rate 100 sccm. The H ₂ concentration in the fourth gas g4 was 5000 ppm. Other processing conditions were the same as in Example 1. The procedure for preparing the polarizing plate sample after the surface treatment and the procedure for measuring the initial adhesive strength and the durable adhesive strength were also the same as in Example 1. The initial adhesive strength was 9.8 N / 25 mm, and the durable adhesive strength was 8.8 N / 25 mm. Therefore, it was confirmed that the adhesive strength can be maintained even when exposed to a humid heat environment.

In Example 4, in the fourth process step, the additive component in the fourth gas g4 and _{H 2,} and the flow rate 160 sccm. The H ₂ concentration in the fourth gas g4 was 8000 ppm. Other processing conditions were the same as in Example 1. The procedure for preparing the polarizing plate sample after the surface treatment and the procedure for measuring the initial adhesive strength and the durable adhesive strength were also the same as in Example 1. The initial adhesive strength was 9.8 N / 25 mm, and the durable adhesive strength was 9.3 N / 25 mm. Therefore, it was confirmed that the adhesive strength can be maintained even when exposed to a humid heat environment.

As is clear from Examples 2 to 4, when the concentration of H ₂ in the fourth gas g4 was in the range of 200 ppm to 8000 ppm, the durable adhesive strength increased as the H ₂ concentration increased. Furthermore, the concentration of H ₂ in the fourth gas g4 against polarizer sample was subjected to treatment with different values as in Example 2-3 in the fourth process step, the measured durable adhesive strength, concentration of H ₂ When it is less than 500 ppm, the durable adhesive strength is lowered, and a desired effect cannot be obtained. When the H ₂ concentration was in the range of 8000 ppm or more, the durable adhesive strength was about the same as that when the H ₂ concentration was changed to 8000 ppm. Therefore, the effect of improving the adhesion durability was saturated.

  In Example 5, in the fourth treatment step, the additive component in the fourth gas g4 was methane, and the flow rate was 160 sccm. The methane concentration in the fourth gas g4 was 8000 ppm. Other processing conditions were the same as in Example 1. The procedure for preparing the polarizing plate sample after the surface treatment and the procedure for measuring the initial adhesive strength and the durable adhesive strength were also the same as in Example 1. The initial adhesive strength was 9.4 N / 25 mm, and the durable adhesive strength was 9.0 N / 25 mm. Therefore, it was confirmed that the adhesive strength can be maintained even when exposed to a humid heat environment.

  In Example 6, in the fourth treatment step, the additive component in the fourth gas g4 was acetylene, and the flow rate was 160 sccm. The acetylene concentration in the fourth gas g4 was 8000 ppm. Other processing conditions were the same as in Example 1. The procedure for preparing the polarizing plate sample after the surface treatment and the procedure for measuring the initial adhesive strength and the durable adhesive strength were also the same as in Example 1. The initial adhesive strength was 10.8 N / 25 mm, and the durable adhesive strength was 10.1 N / 25 mm. Therefore, it was confirmed that the adhesive strength can be maintained even when exposed to a humid heat environment.

Table 1 summarizes the processing conditions and measurement results of Examples 1-6.

In Example 7, using the apparatus 1A of the second embodiment (FIG. 5), an additive component was added to the third gas g3 in the third treatment step. Allyl methacrylate was used as an additive component. The flow rate of the carrier gas (N ₂ ) of the third gas g3, that is, the flow rate of the entire third gas g3 is 40 slm, the flow rate of acrylic acid in the third gas g3 is 7.5 g / min, and the third gas g3 The flow rate of allyl methacrylate therein was 0.375 g / min. The fourth gas g4 in the fourth treatment step was N _{2 20} slm only, and the amount of additive component in the fourth gas g4 was zero. Other processing conditions were the same as in Example 1. The procedure for preparing the polarizing plate sample after the surface treatment and the procedure for measuring the initial adhesive strength and the durable adhesive strength were also the same as in Example 1. The initial adhesive strength was 10.2 N / 25 mm, and the durable adhesive strength was 9.8 N / 25 mm. Therefore, it was confirmed that the adhesive strength can be maintained even when exposed to a humid heat environment.

In Example 8, diallylamine was used as an additive component of the third gas g3 in the third treatment step using the apparatus 1A of the second embodiment (FIG. 5). The flow rate of the carrier gas (N ₂ ) of the third gas g3, that is, the flow rate of the entire third gas g3 is 40 slm, the flow rate of acrylic acid in the third gas g3 is 7.5 g / min, and the third gas g3 The flow rate of ethylenediamine therein was 0.375 g / min. The other processing conditions were the same as in Example 5. The procedure for producing the polarizing plate sample after the surface treatment and the measurement procedure for the initial adhesive strength and the durable adhesive strength were the same as those in Example 1. The initial adhesive strength was 10.1 N / 25 mm, and the durable adhesive strength was 9.6 N / 25 mm. Therefore, it was confirmed that the adhesive strength can be maintained even when exposed to a humid heat environment.

Table 2 summarizes the processing conditions and measurement results of Examples 7 and 8.

[Comparative Example 1]
In Comparative Example 1, the additive component was not added to any of the third gas g3 in the third treatment step and the fourth gas g4 in the fourth treatment step. Other processing conditions were the same as in Example 1. Accordingly, the processing conditions of the third processing step are the same as the processing conditions of the first processing step, and the processing conditions of the fourth processing step are the same as those of the second processing step. The procedure for preparing the polarizing plate sample after the surface treatment and the procedure for measuring the initial adhesive strength and the durable adhesive strength were also the same as in Example 1. The initial adhesive strength was 10.3 N / 25 mm, and the durable adhesive strength was 6.2 N / 25 mm. Therefore, the adhesiveness deteriorated when exposed to a humid heat environment.

[Comparative Example 2]
In Comparative Example 2, 160 sccm of hydrogen (H ₂ ) was added to the discharge product gas (N _{2 20} slm) of the second gas g2 in the second treatment step. No additive component was added to the third gas g3 and the fourth gas g4. Other processing conditions were the same as in Example 1. The procedure for preparing the polarizing plate sample after the surface treatment and the procedure for measuring the initial adhesive strength and the durable adhesive strength were also the same as in Example 1. The initial adhesive strength was 10.3 N / 25 mm, and the durable adhesive strength was 5.5 N / 25 mm. Therefore, the adhesiveness deteriorated when exposed to a humid heat environment.

[Comparative Example 3]
In Comparative Example 3, 160 sccm of hydrogen (H ₂ ) is added to the discharge product gas (N _{2 20} slm) of the second gas g2 in the second treatment step, and as an additive component to the fourth gas g4 in the fourth treatment step, Hydrogen (H ₂ ) was added at 160 sccm. Other processing conditions were the same as in Example 1. The procedure for preparing the polarizing plate sample after the surface treatment and the procedure for measuring the initial adhesive strength and the durable adhesive strength were also the same as in Example 1. The initial adhesive strength was 10.3 N / 25 mm, and the durable adhesive strength was 5.9 N / 25 mm. Therefore, the adhesiveness deteriorated when exposed to a humid heat environment.

Table 3 summarizes the processing conditions and measurement results of Comparative Examples 1 to 3. From the above examples and comparative examples, no additive component is added to the first gas g1 in the first treatment step and the second gas g2 in the second treatment step, and the third gas g2 in the third treatment step, or It was confirmed that the adhesion durability of the TAC film 9 can be improved by adding an additive component to the fourth gas g2 in the four treatment steps.

  The present invention is applicable, for example, to the manufacture of a polarizing plate for a flat panel display (FPD).

PF Polarizing plate 1 Film surface treatment device 7 PVA film 8 PVA adhesive 9 Film to be treated 10 Support section (conveying means)
11 1st roll 12 2nd roll 13 3rd roll 16 1st stage guide roll 17 2nd stage guide roll 21 1st gas supply part 21c 1st gas supply line 22 2nd gas supply part 23 3rd gas supply part 23a Acrylic acid supply part ( Polymerizable monomer supply unit)
23b additive component supply unit 23c third gas supply line 24 fourth gas supply unit 24a discharge gas supply unit 24b additive component supply unit 31 first nozzle 32 second nozzle 33 third nozzle 34 fourth nozzle 41, 43 shielding member 51, 52 Closing member 80 Adhesion promoting film 81 First plasma polymerized film 82 Second plasma polymerized film 83 First condensed layer 84 Second condensed layer 85 Second plasma polymerized film 86 Second condensed layer 91 First processing unit 91a First process Space 92 Second processing section 92a Second processing space (gap between first and second rolls)
93 3rd process part 93a 3rd process space 94 4th process part 94a 4th process space (gap between 2nd, 3rd rolls)
g1 1st gas g2 2nd gas g3 3rd gas g4 4th gas

Claims (8)

A film surface treatment method for treating the surface of a resin-treated film,
A first treatment step of contacting the film to be treated with a first gas containing a vaporized polymerizable monomer;
After the first treatment step or in parallel with the first treatment step, the second treatment step for converting the second gas containing the discharge product gas into plasma and bringing it into contact with the film to be treated;
After the second treatment step, a third treatment step in which a third gas containing a vaporized polymerizable monomer is brought into contact with the film to be treated;
A fourth treatment step after the third treatment step or in parallel with the third treatment step, wherein a fourth gas containing a discharge product gas is converted into plasma and brought into contact with the film to be treated;
The third gas or the fourth gas further contains an additive component, and the additive component is an oxygen gas, a hydrogen gas, a saturated hydrocarbon gas, an unsaturated hydrocarbon gas, or a crosslinking accelerator. A film surface treatment method characterized by the above.   The film surface treatment method according to claim 1, wherein the fourth gas contains 500 ppm to 3000 ppm of oxygen as the additive component.   The film surface treatment method according to claim 1, wherein the fourth gas contains 500 ppm to 10,000 ppm of hydrogen as the additive component.   The film surface treatment method according to claim 1, wherein the fourth gas contains methane, ethylene, or acetylene as the additive component.   2. The film surface treatment according to claim 1, wherein the third gas contains a vaporization gas of a crosslinking accelerator composed of a diallyl compound, a diamine compound, a glycidyl compound, or a hydroxy compound as the additional component. apparatus.   The film surface treatment apparatus according to claim 1, wherein the polymerizable monomer of the first gas and the polymerizable monomer of the third gas are acrylic acid. A film surface treatment apparatus for treating the surface of a resin-treated film,
A support part for supporting the film to be processed;
A first processing unit for performing a process of bringing the first gas containing the vaporized polymerizable monomer into contact with the film to be processed;
A second processing unit for performing a process of converting the second gas containing the discharge generated gas into plasma and bringing it into contact with the film to be processed;
A third processing unit for performing a process of bringing the third gas containing the vaporized polymerizable monomer into contact with the film to be processed;
A fourth processing unit for performing a process of converting the fourth gas containing the discharge generated gas into plasma and bringing it into contact with the film to be processed;
Conveying means for conveying the film to be processed in the order of the first processing unit, the second processing unit, the third processing unit, and the fourth processing unit;
The third gas or the fourth gas further contains an additive component, and the additive component is an oxygen gas, a hydrogen gas, a saturated hydrocarbon gas, an unsaturated hydrocarbon gas, or a crosslinking accelerator. A film surface treatment apparatus characterized by the above. The support portion includes first, second, and third rolls arranged in parallel to each other, and the film to be processed is wound around these rolls, and the first roll, the first roll by the rotation of these rolls 2 rolls, sent in the order of the third roll,
The first processing unit includes a first nozzle that blows out the first gas facing a peripheral surface of the first roll,
The second processing unit includes a second nozzle that blows the second gas into a gap between the first roll and the second roll, and the first and second rolls are in the vicinity of atmospheric pressure between each other. Comprising a pair of electrodes that generate a discharge;
The third processing unit includes a third nozzle that blows out the third gas facing the peripheral surface of the second roll,
The fourth processing unit includes a fourth nozzle that blows the fourth gas into a gap between the second roll and the third roll, and the second and third rolls are in the vicinity of atmospheric pressure between each other. The film surface treatment apparatus according to claim 7, comprising a pair of electrodes that generate electric discharge.

Images