JP2010070309A - Optical film and its manufacturing method - Google Patents

Abstract

Disclosed is a method for producing an optical film, which can prevent a film surface or film from being damaged by dust or the like, and can prevent nicks and wrinkles from occurring.
In a method of manufacturing an optical film in which a thin film 14 is laminated by vacuum film formation on an underlayer 12 previously layered on a film 10, embossing or slit lines are formed at both ends of the film where the underlayer 12 is layered. A winding step of winding and winding the processed tape 82 is provided.
[Selection] Figure 4

Description

  The present invention relates to an optical film and a method for producing the same, and more particularly to an optical film in which a base layer is provided on the film and a thin film is provided on the base layer by a vacuum film forming method and a method for producing the same.

  Optical films such as gas barrier films, protective films, optical filters, and antireflection films are used in various devices such as optical elements, display devices such as liquid crystal displays and organic EL displays, semiconductor devices, and thin film solar cells.

  In addition, film formation (thin film formation) by a vacuum film formation method such as sputtering or plasma CVD is used for manufacturing these optical films. In order to perform film formation efficiently and with high productivity by a vacuum film formation method, film formation is continuously performed on a long base material.

  As equipment for carrying out such a film forming method, a supply roll formed by winding a long base material (film) in a roll shape, and a winding roll for winding a film-formed base material in a roll shape A so-called roll-to-roll film forming apparatus is known. This roll-to-roll film forming device inserts a long base material from a supply roll to a take-up roll through a predetermined path passing through a film forming chamber for forming a film on the base material by plasma CVD, and supplies it. The film formation is continuously performed on the substrate to be conveyed in the film formation chamber while the base material is fed from the roll and the film-formed base material is taken up by the take-up roll in synchronization.

  When the film thus formed is wound up, there has been a problem that the film surface or film is damaged by dust or winding deviation adhering to the film.

Therefore, for example, in Patent Document 1, as a method of winding a film that can prevent a lateral shift during winding, can be wound up with no appearance of scratches, and has a good appearance, A method is disclosed in which a concavo-convex portion is formed (knurled) on at least one surface of both end portions to make the height of the convex portion higher than the average height of the film, and then wound into a roll with a winder. Further, in Cited Document 2, as a winding method in which the wound form of the wound film is good and the winding is difficult to shift, the end surface of the film wound on the core is wound so that the end surface has a predetermined uneven shape. By winding the film to be taken while traversing in the width direction with a predetermined amplitude and a predetermined cycle, even if the film has a thickness unevenness in the width direction, the thick part and the thin part are laminated together, It is disclosed that a film having a uniform winding pressure and a good winding shape can be wound.
JP-A-8-175708 Japanese Patent Laid-Open No. 10-212059

  By the way, an optical film such as a gas barrier film or a protective film is not necessarily a single layer, for example, an organic film (underlayer) mainly composed of a polymer is formed on a base material such as a plastic film, An optical film (laminated film) obtained by forming an inorganic film (thin film) made of an inorganic material thereon is also known.

  Thus, when forming a base layer and a thin film on a film, when forming a base layer, a film is once wound up as a roll, and the wound film is used for the unwinding part of a vacuum film-forming apparatus. It is common practice to install and form a thin film on the underlying layer of the film.

  In this case, in order to unwind the film under vacuum, in the method of Patent Document 1 or Patent Document 2, after the winding when the underlayer is formed, air enters and exits the central portion of the film wound as a roll. There was a problem that wrinkles and wrinkles occurred because it was not possible. In addition, even if knurling like patent document 1, an uneven | corrugated | grooved part will be compressed with the winding pressure at the time of winding, and air cannot enter / exit into the film center part.

  The present invention has been made in view of such circumstances, and it is possible to prevent damage to the film surface and film due to dust and the like, and to prevent occurrence of nicks and wrinkles. An object is to provide a manufacturing method.

  In order to achieve the above object, the invention according to claim 1 is a method of manufacturing an optical film in which a thin film is laminated by vacuum film formation on an underlayer previously formed on the film. The film is provided with a winding process in which a tape with embossing or slitting is wound around both ends of the film.

  According to claim 1, air enters and exits the central portion of the film wound up as a roll by winding and winding the tape with embossed or slitted processing around both ends of the film on which the underlayer is provided. Therefore, it is possible to prevent the occurrence of nicks (bending and pushing marks) and wrinkles. Moreover, since it can suppress that the film | membrane on a film overlaps with a film, it can prevent that a film surface and a film are damaged by dust etc.

  In particular, when forming a thin film by a vacuum film-forming method after the winding process, because the installation environment of the roll changes from the atmosphere to a vacuum state, it is preferable that the air can enter and exit from the center of the film wound as a roll, By allowing air to enter and exit, it is possible to prevent the underlying layer from being damaged by dust and the like, and to prevent nicks and wrinkles from occurring.

  The invention of claim 2 is characterized in that, in claim 1, the thickness of the tape is 50 μm or more, and the depth of the embossing or slit processing is in the range of 20 to 50% of the thickness of the tape. .

  According to claim 2, it is preferable that the thickness of the tape is 50 μm or more, and the depth of embossing or slit processing is in the range of 20 to 50% of the thickness of the tape. When the thickness of the tape is less than 50 μm, the embossing or slit processing of the tape is crushed by the winding pressure. When the embossing or slitting depth is less than 20% of the tape thickness, the embossing or slitting process of the tape is crushed by the winding pressure, and air is wound on the center of the film wound up as a roll. If it becomes impossible to enter and exit and the depth of embossing or slitting is greater than 50% of the tape thickness, the embossed or slitting part of the tape has no strength and the shape processed by the winding pressure is crushed. Will be.

  A third aspect of the present invention is an optical film manufactured by the manufacturing method according to the first or second aspect.

  Since the optical film produced by the film production method of the present invention is an optical film free from nicks and wrinkles, it can be suitably used for various devices such as optical elements, display devices, semiconductor devices, and thin film solar cells. .

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the optical film which can prevent that a base layer and a film are damaged with dust etc., and can prevent that a nick and a wrinkle generate | occur | produce can be provided.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. The present invention will be described with reference to the following preferred embodiments, but can be modified in many ways without departing from the scope of the present invention, and other embodiments than the present embodiment can be used. be able to. Accordingly, all modifications within the scope of the present invention are included in the claims. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to”.

  Hereinafter, the manufacturing method of the optical film of this invention is demonstrated. In the following embodiment, the case where the coating liquid for forming the underlayer is a coating liquid containing a radiation curable monomer or oligomer will be described.In the present invention, the coating liquid for forming the underlayer is, A thermosetting resin may be used. In this case, the UV irradiation apparatus constituting the organic film forming apparatus in the following description is unnecessary. In the following embodiments, the case where the underlayer is an organic film and the thin film is an inorganic film will be described as an example, but the present invention is not limited thereto.

  In FIG. 1, the conceptual diagram of the optical film manufactured by the manufacturing method of an optical film is shown.

  As shown in FIG. 1, in the method for producing an optical film, a base layer 12 mainly composed of a predetermined polymer is formed (formed) on the surface of a base material B (film raw fabric). A thin film 14 is formed thereon by a vacuum film forming method to manufacture a laminate (hereinafter also referred to as a laminated film or an optical film) 10.

  As an example of the method for producing an optical film, an organic film forming apparatus 20 for forming a base layer (organic film) 12 on the surface of the base material B, and a thin film (inorganic film) 14 on the base layer 12 (surface). The laminated film 10 is manufactured by the inorganic film forming apparatus 22 for forming a film.

  FIG. 2A conceptually shows an example of an organic film forming apparatus 20 that implements the method for producing an optical film.

  The organic film forming apparatus 20 includes a coating unit 26, a heating unit 28, and a UV irradiation unit 30. A coating solution containing a radiation curable monomer or oligomer prepared in advance is applied to the base material B. The base layer 12 is formed by coating with the above, drying with the heating means 28, and polymerizing with the UV irradiation device 30.

  The organic film forming apparatus 20 forms an organic film (underlayer) by roll-to-roll, and the base material B is loaded on the rotary shaft 32 as a base material roll 40 and is conveyed in the longitudinal direction. An organic film is formed, and the substrate Bo on which the organic film is formed is wound around the winding shaft 34 as a roll 42.

  The base material B sent out from the base material roll 40 is first transported to the coating means 26. In the coating means 26, a coating solution containing a radiation curable monomer or oligomer that becomes the base layer 12 prepared in advance is applied to the surface of the base material B. All the usual liquid application methods can be used for applying the coating liquid.

  The substrate B is then conveyed to the heating means 28. The heating unit 28 dries the solvent in the coating solution applied by the coating unit 26. There is no particular limitation on the heating method of the coating liquid, and the coating liquid can be heated before reaching the UV irradiation device 30 depending on the conveyance speed of the base material B, such as heating with a heater or heating with warm air. Any known heating means can be used.

  Next, the base material B is conveyed to the UV irradiation device 30. In the UV irradiation device 30, the coating solution coated by the coating unit 26 and heated and dried by the heating unit 28 is irradiated with UV (ultraviolet rays) to polymerize a radiation curable monomer or oligomer, thereby forming the underlayer 12. Film.

  In the present invention, the tape 82 is unwound from the tape unwinding machine 81, and the tape 82 having embossed or slit-like processing applied to both ends of the base material (film) Bo is wound around the winding shaft 34. .

  Next, the base material roll 42 around which the base material Bo on which the base layer 12 is formed is loaded into the inorganic film forming apparatus 22 as conceptually shown in FIG.

  The inorganic film forming apparatus 22 forms (forms) the inorganic film 14 on the surface of the base material Bo (that is, the surface of the base layer 12) by a vacuum film forming method, and includes a supply chamber 50, a film forming chamber 52, And a winding chamber 54.

  Similarly to the organic film forming apparatus 20, the inorganic film forming apparatus 22 is an apparatus that performs film formation by roll-to-roll. The substrate Bo is sent out from the base roll 42, and the thin film 14 is formed while being conveyed in the longitudinal direction. The optical film 10 having the base layer 12 and the thin film 14 formed thereon is wound up in a roll shape by a winding shaft 58.

  The supply chamber 50 includes a rotation shaft 56, a guide roller 60, and a vacuum exhaust unit 61. Further, the organic film forming apparatus 20 includes a winder 83 that winds the tape 82 wound around the base material Bo of the base material roll 42.

  In the inorganic film forming apparatus 22, the base material roll 42 obtained by winding the base material Bo formed by forming the base layer 12 on the base material B and the tape 82 is loaded on the rotation shaft 56 of the supply chamber 50. When the substrate roll 42 is loaded on the rotating shaft 56, the substrate Bo passes through a predetermined conveyance path from the supply chamber 50 through the film forming chamber 52 to the winding shaft 58 of the winding chamber 54. (Passed through). Also in the inorganic film forming apparatus 22, the feeding of the base material Bo from the base material roll 42 and the winding of the optical film 10 on the take-up shaft 56 are performed in synchronization, and the long base material Bo is conveyed in a predetermined manner. The thin film 14 is continuously formed on the base material Bo while being transported in the longitudinal direction along the path.

  In the supply chamber 50, the rotating shaft 56 is rotated clockwise in the drawing by a driving source (not shown) to feed the substrate Bo from the substrate roll 42, and a predetermined path is guided by the guide roller 60. It is sent to the film formation chamber 52.

  Further, a vacuum exhaust means 61 is disposed in the supply chamber 50, and the inside of the supply chamber 50 is depressurized to a predetermined degree of vacuum (pressure) corresponding to the film formation pressure in the film formation chamber 52. This prevents the pressure in the supply chamber 50 from adversely affecting the pressure (film formation) in the film formation chamber 52. The evacuation unit 61 may be a publicly known one as with the evacuation unit 72 of the film formation chamber 52 described later.

  The guide roller 60 that comes into contact with the base layer 12 in a vacuum is preferably a stepped roller that comes into contact only with the end of the base material Bo (the end in the direction (width direction) perpendicular to the transport direction).

  In addition to the illustrated members, the supply chamber 50 includes various members for transporting the base material Bo along a predetermined path, such as a pair of transport rollers and a guide member for regulating the position of the base material Bo in the width direction. (Conveying means) may be included. However, during the formation of the thin film 14, the inside of the supply chamber 50 is at a degree of vacuum corresponding to the pressure in the film formation chamber, so that the member that contacts the base layer 12 is the same as the guide roller 60 that is a stepped roller. It shall be the thing which has the structure which contacts only the edge part of base material Bo.

  The substrate Bo is guided by the guide roller 60 and conveyed to the film forming chamber 52.

  In the film forming chamber 52, the thin film 14 is formed (formed) on the surface of the base material Bo (that is, the surface of the base layer 12) by a vacuum film forming method. In the illustrated example, the film forming chamber 52 includes a drum 62, film forming means 64 a, 64 b, 64 c, and 64 d, guide rollers 68 and 70, and a vacuum exhaust means 72. In the case where the film formation chamber 52 performs film formation by sputtering, plasma CVD, or the like, the film formation chamber 52 is further provided with a high-frequency power source or the like.

  The substrate Bo is transferred to the film forming chamber 52 from a slit 74 a formed in a partition wall 74 that separates the supply chamber 50 and the film forming chamber 52.

  In addition, the inorganic film forming apparatus 22 in the illustrated example is preferably provided with a vacuum evacuation unit in the supply chamber 50 and the winding chamber 54, and the supply chamber 50 and the winding chamber are arranged according to the film forming pressure in the film forming chamber 52. Although the chamber 54 is also evacuated, the apparatus for carrying out the present invention is not limited to this. For example, the supply chamber 50 and the winding chamber 54 are not provided with a vacuum evacuation unit, and a slit through which the base material Bo passes can be provided at a minimum without allowing the base material B to pass through the slit. The film forming chamber 52 may be configured to be substantially airtight by setting the size to the above. Alternatively, the supply chamber 50 and the winding chamber 54 are provided with a sub-chamber through which the substrate B passes between the supply chamber 50 and the winding chamber 54 and the film forming chamber 52 without providing a vacuum exhaust means. The sub chamber may be evacuated by a vacuum pump.

  When a sub-chamber or the like is provided upstream of the film forming chamber 52 (upstream in the transport direction of the base material B), the means for transporting the base material in the sub-chamber or the like is also in contact with the base layer 12. Needs to be configured to contact only the end of the base material Bo.

  The drum 62 of the film forming chamber 52 is a cylindrical member that rotates counterclockwise in the drawing around the center line.

  The base material Bo supplied from the supply chamber 50 and guided to a predetermined path by the guide roller 68 is hung around a predetermined area on the peripheral surface of the drum 62 and supported / guided by the drum 62 while being predetermined. The thin film 14 is formed on the surface (on the base layer 12) by the film forming means 64a to 64d and the like. When the film formation chamber 52 performs film formation by sputtering, plasma CVD, or the like, the drum 62 may be grounded (earthed) so as to act as a counter electrode, or a high-frequency power source. May be connected.

  The film forming means 64a to 64d are for forming the thin film 14 on the surface of the base material B by a vacuum film forming method.

  Here, in the manufacturing method of the present invention, the method for forming the thin film 14 is not particularly limited, and a known vacuum film forming method (vapor phase deposition method) such as CVD, plasma CVD, sputtering, vacuum deposition, ion plating, or the like. ) Are all available.

  Therefore, the film forming means 64a to 64d are configured by various members according to the vacuum film forming method to be performed.

  For example, if the film formation chamber 52 performs film formation of the thin film 14 by the ICP-CVD method (inductively coupled plasma CVD), the film forming units 64a to 64d include induction coils for forming an induction magnetic field, It has gas supply means for supplying a reaction gas to the film formation region.

  If the film forming chamber 52 is for forming the thin film 14 by the CCP-CVD method (capacitive coupling type plasma CVD), the film forming means 64 a to 64 d are hollow and have a large number of surfaces facing the drum 46. A high-frequency electrode having a small hole and connected to a reaction gas supply source, a shower electrode acting as a reaction gas supply means, and the like are configured.

  If the film forming chamber 52 is for depositing the thin film 14 by the CVD method, the film forming means 64a to 64d are configured to include a reaction gas introducing means and the like.

  Further, if the film forming chamber 52 is for depositing the thin film 14 by sputtering, the film forming means 64a to 64d are configured to include a target holding means, a high frequency electrode, a sputtering gas supply means, and the like. The

  The vacuum evacuation means 72 evacuates the film forming chamber 52 to a degree of vacuum corresponding to the film formation of the thin film 14 by a vacuum film forming method.

  There is no particular limitation on the vacuum exhaust means 72, and a vacuum pump such as a turbo pump, a mechanical booster pump, and a rotary pump, an auxiliary means such as a cryocoil, an ultimate vacuum degree and an exhaust amount adjusting means, etc. are used. Various known (vacuum) evacuation means used in vacuum film forming apparatuses can be used.

  The substrate Bo, that is, the optical film 10 on which the thin film 14 is formed by the film forming units 64a to 64d while being supported / conveyed by the drum 62, is guided to a predetermined path by the guide roller 70, and is conveyed to the winding chamber 54. Then, it is wound up in a roll shape by the winding shaft 58. The laminated film (optical film) roll wound up in a roll shape is subjected to the next step.

  In the method for producing an optical film as described above, in the present invention, tape 82 embossed or slit-processed is wound around both ends of the base material Bo on which the base layer 12 is formed on the base material B. I have to.

  FIG. 3 (A) is a view of the base material roll 42 wound from around the tape Bo that has been embossed or slit-worked around both ends of the base material Bo. FIG. 3B is an enlarged view of a cross section of a circled portion A in FIG.

  Usually, when the base material Bo with the base layer 12 formed on the base material B is taken up by the take-up shaft 34, a tape 82 having an embossed or slit-like process is wound around both ends of the base material Bo. Not taking. Therefore, there has been a problem that damage such as scratches is given to the base material Bo due to dust or winding deviation adhering to the base material Bo.

  As in the present invention, by wrapping and winding the tape 82 embossed or slitted around both ends of the base material Bo, the base material Bo is damaged by dust or winding deviation. Can be prevented.

  FIG. 4 is an enlarged view of the tape 82. FIG. 4A shows the tape 82 sandwiched between the surface of the embossed tape and the base material Bo and the base material Bo. FIG. 4B shows a cross section when the tape 82 is sandwiched between the base material Bo and the base material Bo. And are shown.

  By winding and winding the tape 82 embossed or slitted as shown in FIG. 4 around both ends of the substrate Bo, air can pass through the tape 82 embossed or slitted. Air can enter and exit the central portion of the base material Bo wound as the roll 42. Therefore, when the substrate roll 42 is moved from the organic film forming apparatus 20 to the inorganic film forming apparatus 22, the installation environment of the substrate roll 42 changes from the atmosphere to the vacuum state, but the central portion of the substrate Bo wound up as a roll. Since air can flow in and out, the present invention can prevent the occurrence of nicks (bending and pushing marks) and wrinkles.

  Here, the thickness X of the tape 82 is preferably 50 μm or more, and the depth x of the embossing or slit processing is preferably in the range of 20 to 50% of the thickness of the tape.

  If the thickness X of the tape is less than 50 μm, the embossing or slit processing of the tape 82 is crushed by the winding pressure. If the embossing or slitting depth x is less than 20% of the tape thickness X, the tape embossing or slitting process is crushed by the winding pressure, and the base roll 42 is wound up. Air cannot enter or leave the center of the material Bo. On the other hand, when the depth x of embossing or slitting is greater than 50% of the thickness X of the tape, the strength of the embossed or slitting part is weak, and the shape processed by the winding pressure is crushed.

  Thus, according to the method for producing an optical film of the present invention, it is possible to prevent the film surface or film from being damaged by dust or the like, and to prevent the occurrence of nicks and wrinkles.

  The underlayer 12 is preferably smooth and has a high film hardness. The smoothness of the underlayer 12 is preferably 10 nm or less, and more preferably 2 nm or less, as an average roughness (Ra value) of 10 μm square.

It is preferable that the film hardness of the underlayer 12 has a certain degree of hardness. The preferable hardness is preferably 100 N / mm ² or more, and more preferably 200 N / mm ² or more as the indentation hardness when measured by the nanoindentation method. The pencil hardness is preferably HB or higher, more preferably H or higher.

  In the present invention, the base material B on which the base layer 12 and the thin film 14 are formed is not particularly limited, and various base films 12 described later such as various resin films such as PET films and various metal sheets such as aluminum sheets. As long as the thin film 14 can be formed by vacuum film formation, all the various base materials (base films) used for various functional films such as gas barrier films, optical films and protective films are used. Is possible.

  Moreover, the base material B may have a surface on which various films such as a protective film and an adhesive film are formed.

  The coating film for forming the base layer (organic film) 12 is a film mainly composed of a radiation curable monomer or oligomer. Specifically, the monomer or oligomer used is preferably a monomer or oligomer that has two or more ethylenically unsaturated double bonds and undergoes addition polymerization upon irradiation with light. Examples of such monomers and oligomers include compounds having at least one addition-polymerizable ethylenically unsaturated group in the molecule and having a boiling point of 100 ° C. or higher at normal pressure. Examples include monofunctional acrylates and monofunctional methacrylates such as polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate and phenoxyethyl (meth) acrylate; polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) ) Acrylate, trimethylolethane triacrylate, trimethylolpropane tri (meth) acrylate, trimethylolpropane diacrylate, neopentyl glycol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, di Pentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, hexane All di (meth) acrylate, trimethylolpropane tri (acryloyloxypropyl) ether, tri (acryloyloxyethyl) isocyanurate, tri (acryloyloxyethyl) cyanurate, glycerin tri (meth) acrylate; multifunctional such as trimethylolpropane and glycerin Polyfunctional acrylates and polyfunctional methacrylates such as those obtained by adding ethylene oxide or propylene oxide to alcohol and then (meth) acrylated can be mentioned.

  Further, urethane acrylates described in JP-B-48-41708, JP-B-50-6034 and JP-A-51-37193; JP-A-48-64183, JP-B-49-43191 And polyester acrylates described in JP-B-52-30490; polyfunctional acrylates and methacrylates such as epoxy acrylates which are reaction products of epoxy resin and (meth) acrylic acid.

  Among these, trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and dipentaerythritol penta (meth) acrylate are preferable.

  In addition, “polymerizable compound B” described in JP-A-11-133600 can also be mentioned as a preferable example.

  Examples of the photoinitiator or photoinitiator system used include vicinal polyketaldonyl compounds disclosed in US Pat. No. 2,367,660 and acyloin described in US Pat. No. 2,448,828. Ether compounds, aromatic acyloin compounds substituted with α-hydrocarbons described in US Pat. No. 2,722,512, polynuclear quinone compounds described in US Pat. Nos. 3,046,127 and 2,951,758, US Pat. No. 3549367, a combination of a triarylimidazole dimer and a p-aminoketone, a benzothiazole compound and a trihalomethyl-s-triazine compound described in JP-B-51-48516, US Pat. No. 4,239,850 Trihalomethyl-triazine compounds described, USA And tri halomethyl oxadiazole compounds as described in Patent No. 4,212,976 A1. In particular, trihalomethyl-s-triazine, trihalomethyloxadiazole, and triarylimidazole dimer are preferable.

In addition, “polymerization initiator C” described in JP-A-11-133600 can also be mentioned as a preferable example. The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 10% by mass, based on the solid content of the coating solution. Light irradiation for the polymerization of the liquid crystalline compound is preferably performed using ultraviolet rays. The irradiation energy ^is preferably ^{20mJ / cm 2 ~50J / cm 2} , further preferably 100 to 2000 mJ / cm ^2. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions.

  Examples of the method for forming the underlayer 12 include a normal solution coating method or a vacuum film forming method.

  Examples of the solution coating method include a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, a wire bar coating method, a gravure coating method, a slide coating method, or a hopper described in US Pat. No. 2,681,294. It can apply | coat by the extrusion-coating method which uses-.

In addition, acrylate and methacrylate are subject to polymerization inhibition by oxygen in the air. Therefore, in the present invention, when these are used as the organic film 12, it is preferable to lower the oxygen concentration or oxygen partial pressure during polymerization. When the oxygen concentration during polymerization is lowered by the nitrogen substitution method, the oxygen concentration is preferably 2% or less, and more preferably 0.5% or less. When the oxygen partial pressure during polymerization is reduced by the decompression method, the total pressure is preferably 1000 Pa or less, and more preferably 100 Pa or less. In addition, it is particularly preferable to perform ultraviolet polymerization by irradiating energy of ² J / cm ² or more under a reduced pressure condition of 100 Pa or less.

  In the present invention, the polymerization rate of the monomer is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more. The polymerization rate here means the ratio of the reacted polymerizable groups among all polymerizable groups in the monomer mixture (for example, acrylate and methacrylate, acryloyl group and methacryloyl group).

  When manufacturing protective films for various devices and devices such as display devices such as organic EL displays and liquid crystal displays as laminated films (optical films), if a silicon oxide film or the like is formed as the inorganic film 14 Good.

  Furthermore, when manufacturing an optical film such as a light reflection preventing film, a light reflection film, and various filters, as the inorganic film 14, a film made of a material having or expressing a desired optical characteristic may be formed. Good.

  Especially, since the inorganic film 14 having excellent gas barrier properties can be formed by the excellent surface smoothness of the organic film 12, the present invention is most suitable for the production of gas barrier films.

  As mentioned above, although the manufacturing method of the optical film of this invention was demonstrated in detail, this invention is not limited to the said embodiment, You may perform various improvement and a change in the range which does not deviate from the summary of this invention. Of course.

  Hereinafter, the present invention will be described with reference to specific examples of the present invention.

  98 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was dissolved in 900 g of methyl ethyl ketone solvent. To the resulting solution, 2 g of a photopolymerization initiator (Irgacure 907, manufactured by Ciba Fine Chemicals Co., Ltd.) was added, and the mixture was stirred and dissolved to obtain a coating solution.

  As the base material, a TAC (triacetyl cellulose film) manufactured by Fuji Film Co., Ltd. having a thickness of 80 μm and a width of 1460 mm was used. The running speed of the film was 10 m / min.

After passing through a roll heated to 90 ° C., a coating solution containing a polymerizable compound having the above composition was continuously applied with a wire bar in the coating step. After the coating solution was applied, it was dried at 100 ° C. in the heating step. Next, a UV irradiation apparatus (Light Hammer 10, 240 W / cm, manufactured by Fusion UV Systems) equipped with a D-Bulb having a strong emission spectrum at 350 to 400 nm as a UV light source is used. At 30, UV irradiation was performed at 0.4 W / cm ² and 0.4 J / cm ² for 1 second at a position 5 mm from the focal point to polymerize the polymerizable compound. Then, it stood to cool to room temperature and wound up the elongate film (base material Bo) in which the base layer (film thickness: 0.5 micrometer) was formed.

  Here, when winding the base material Bo, the tape shown in Table 1 below was wound around the ear end. In addition, the embossing and slit eye processing described in Table 1 indicate the shapes shown in FIG. The tape width was 20 mm.

  The wound roll was brought into a sputtering apparatus, and an aluminum oxide film having a thickness of 50 nm was formed as a thin film 14 on the underlayer 12. The aluminum oxide film used aluminum as a target, argon as a discharge gas, and oxygen as a reaction gas.

Here, the number of defects of the manufactured optical film was evaluated. The number of defects of 1 μm or more was counted per unit area and evaluated according to the following criteria.
A: Number of defects is 5 / cm ² or less B: Number of defects is 10 / cm ² or less
X: The number of defects exceeds 10 / cm ²

  From the above, in the method for producing an optical film in which a thin film is laminated on the underlayer by vacuum film formation, by winding the tape with embossed or slit-like processing on both ends of the film where the underlayer is layered, It can be seen that the number of defects in the optical film can be suppressed.

The figure which shows the optical film manufactured by the manufacturing method of an optical film The figure which shows an example of the apparatus which enforces the manufacturing method of an optical film The figure which shows the base-material roll which wound the tape around the both ends of the base material and wound up The figure which shows the surface and cross section of the tape to which embossing or slitting was performed

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Laminated film (optical film), 12 ... Underlayer (organic film), 14 ... Thin film (inorganic film), 20 ... Organic film-forming apparatus, 22 ... Inorganic film-forming apparatus, 26 ... Application | coating means, 28 ... Drying means, DESCRIPTION OF SYMBOLS 30 ... UV irradiation apparatus, 52 ... Film formation chamber, 64a, 64b, 64c, 64d ... Film formation means, 81 ... Tape unwinding machine, 82 ... Tape, 83 ... Tape winder

Claims (3)

In the method for producing an optical film in which a thin film is laminated by vacuum film formation on a base layer previously provided on the film
A method for producing an optical film, comprising a winding step of winding and winding a tape embossed or slit-finished on both ends of the film on which the underlayer is provided.   2. The method for producing an optical film according to claim 1, wherein the tape has a thickness of 50 μm or more, and the embossing or slitting depth is in a range of 20 to 50% of the thickness of the tape. .   An optical film manufactured by the manufacturing method according to claim 1.

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