JP2008049604A - Method for manufacturing transparent laminate and its manufacturing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a laminate continuously sticking under a vacuum condition capable of accurately detecting mixing of air bubbles and minimizing generation of defected articles. <P>SOLUTION: The method for manufacturing a transparent laminate has at least a process obtaining the laminate by sticking continuously at least two strips, and the process of irradiating a continuously running laminate with a light and measuring a ratio of diffused light component to the whole transmitted light passing through the laminated body, and at least two processes are performed under the vacuum condition. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a transparent laminated film and an apparatus for producing the same, and more particularly to a method for producing a display filter having electromagnetic wave shielding performance.

  A transparent laminate, for example, a laminate film in which various optical functional layers are laminated on a transparent substrate made of a resin film, has applications as a filter for a display such as a liquid crystal display or a plasma display.

  For example, a front filter disposed in front of a display panel of a plasma display is required to have electromagnetic wave shielding performance, near infrared shielding performance, antireflection performance, etc., and these functional layers are provided individually or in combination. A laminate in which two or more resin films are bonded via an adhesive or an adhesive is used.

  Needless to say, the display filter is required to have high transparency, but the transparency may be impaired due to air bubbles and foreign matters mixed in the manufacturing process of the laminate. In particular, the mixing of bubbles in the bonding process is a major factor in reducing transparency.

  Therefore, as a means of increasing the transparency that has been reduced due to the mixing of bubbles, the laminated body is heated and pressurized for a long time (generally 1 hour or more) with an autoclave or the like to refine and diffuse the bubbles mixed in the laminated body. The method of achieving transparency is adopted. However, this autoclave treatment has a small amount of treatment per hour and has a limit in increasing the amount of treatment, which has been a big problem in increasing production and increasing production efficiency.

  On the other hand, a method of bonding under reduced pressure (vacuum laminating) is known as means for suppressing air bubble mixing during bonding. This method has an advantage that it can be continuously bonded, and it is possible to mass-produce a laminated body free from bubbles by continuously bonding two long strips under reduced pressure. Therefore, the method of bonding under reduced pressure is an extremely effective method for improving productivity.

  The method of laminating under reduced pressure is originally performed to suppress air bubble mixing, and it is not usually done online to observe the air bubble contamination of the laminate obtained by bonding. It was not subject to. Therefore, the present condition is that the suitable bubble detection method is not proposed in the bonding under reduced pressure.

  However, the highly transparent laminate targeted by the present invention needs to be produced in a state where there is almost no air bubble mixing, but there are subtle variations in the degree of pressure reduction and bonding conditions (for example, nip roll pressure) in the bonding process. Alternatively, bubbles may be mixed due to fluctuations in the physical properties of the material used, such as the rough state of the bonding surface of the band, the thickness profile of the band, and the adhesiveness of the adhesive. Once air bubbles are mixed, the above continuous bonding method has a risk of producing a large amount of defective products. Accordingly, it is desirable to detect bubbles in real time on-line within the manufacturing process.

  As a method for detecting bubbles in continuous bonding under normal pressure, a method for continuously measuring capacitance is described in JP-A-7-76043 (Patent Document 1), and a method using a CCD camera is disclosed in JP-A-9 -210658 (Patent Document 2) and JP-A-2003-344302 (Patent Document 3).

However, the former method of measuring capacitance cannot provide sufficient measurement accuracy with the highly transparent laminate targeted by the present invention, and the latter method using a CCD camera is online in the production process. The usable CCD camera has a problem that it cannot be used because the periphery of the lens and the element of the CCD camera is broken under reduced pressure. Therefore, in the manufacturing process of the highly transparent laminate targeted by the present invention, At present, a method suitable for air bubble detection has not been proposed yet.
JP-A-7-76043 Japanese Patent Laid-Open No. 9-210658 JP 2003-344302 A

  Accordingly, an object of the present invention is to accurately detect the mixing of bubbles that affect transparency and minimize the occurrence of defective products in a method for manufacturing a laminate that is continuously bonded under reduced pressure. It is to provide a manufacturing method that can be used. Another object of the present invention is to provide a manufacturing apparatus for realizing the above manufacturing method. In particular, the present invention is to provide a production method suitable for a filter for a display such as a plasma display.

The above object of the present invention has been basically achieved by the following invention.
(1) A method for producing a transparent laminate, the step of continuously laminating at least two strips to obtain a laminate, and irradiating light to the continuously running laminate to transmit the laminate And measuring the ratio of the diffused light component to the total transmitted light. At least the two steps are performed under reduced pressure.
(2) The manufacturing method of the laminated body as described in said (1) by which bonding of the said strip | belt-shaped body is performed via an adhesive material or an adhesive material.
(3) The manufacturing method of the laminated body as described in said (1) or (2) whose one of the said strip | belt shaped objects has a conductive mesh on a plastic film.
(4) The other of the strips has an antireflection layer or an antiglare layer on the plastic film (the method for producing a laminate according to (3).
(5) The manufacturing method of the laminated body as described in any one of said (1)-(4) whose said laminated body is a filter for a display.
(6) A transparent laminate manufacturing apparatus, comprising: a decompression chamber; unwinding means for holding and unwinding at least two roll-shaped strips in the decompression chamber; and at least two strips Bonding means for bonding, winding means for winding the laminated body obtained in a roll form, and air bubble detection arranged between the bonding means and the winding means And the bubble detecting means has a light source part and a light receiving part arranged with the laminate interposed therebetween, and the light receiving part obtains a ratio of the diffused light component to the total transmitted light transmitted through the laminate. The manufacturing apparatus of the laminated body which has.

  According to the present invention, it is possible to accurately detect the mixing of bubbles, which greatly affects the transparency of the laminate, in a continuous production process, thereby minimizing the amount of defective products generated. In particular, the present invention is suitable for mass production of display filters having high transparency and electromagnetic wave shielding performance.

  The transparency of the transparent laminate targeted by the present invention means, for example, that it is transparent to the extent that it can be used by being attached to an image display area of a display. More specifically, the haze value (based on JIS K7136; 2000 version) of the laminate is preferably 10% or less, and particularly preferably 5% or less.

  As the transparent laminate of the present invention, a laminate of a resin film and an adhesive or an adhesive, a laminate of a resin film and a resin film, a laminate of a metal foil and a resin film, or a metal foil and an adhesive or Examples include a laminate with an adhesive. The bonding between the resin film and the resin film or the metal foil includes a mode of bonding via an adhesive material (adhesive) and a mode of bonding using the adhesiveness of the resin film.

  As described above, the band-shaped body used in the present invention includes a resin film, a band-shaped sheet of an adhesive material or an adhesive, a metal foil, and the like, and an adhesive in which an adhesive (adhesive) is laminated on the resin film in advance. Resin film with material (adhesive), metal foil laminated resin film in which metal foil is pre-laminated on resin film, and functionality in which various functional layers (for example, infrared shielding layer, antireflection layer, etc.) are pre-coated on resin film A film or the like can be used. Moreover, the metal mesh processed into the mesh pattern shape can be used as said metal foil.

  The belt-like body used in the present invention is not necessarily required to have high transparency as a single body, and the laminated body obtained by pasting may exhibit high transparency.

  The present invention includes a mode in which two strips are pasted together and further pasted with another strip and a mode in which three or more strips are pasted almost simultaneously. In this case, the detection of air bubbles may be performed at any stage after bonding, but it is necessary to carry out on-line under reduced pressure.

  The laminate of the present invention is preferably a display filter, and particularly preferably a display filter having electromagnetic wave shielding performance used as a front filter for a plasma display or the like.

  Hereinafter, the structure and manufacturing method of the display filter, which is a representative example of the transparent laminate of the present invention, will be described in detail.

  A preferable configuration of the display filter of the present invention includes at least an optical functional film having an optical functional layer imparted with antireflection properties and / or antiglare properties as a surface layer, and an electromagnetic wave shielding layer.

  As the electromagnetic wave shielding layer used in the present invention, a conductive mesh is preferable. As the conductive mesh, a fiber mesh coated with a synthetic fiber or metal fiber mesh, a metal mesh obtained by processing a metal foil, and a conductive paste are pattern printed. , One that has been subjected to conductive processing after pattern printing of semiconductor paste, one that has been subjected to conductive patterning after conductive paste, one that has been subjected to conductive processing after photosensitive patterning of semiconductor paste, and metal foil is processed into a mesh by laser ablation And the like. As the material of the metal foil used for the conductive mesh, a conductive metal such as silver, gold, palladium, copper, indium, tin, or an alloy of silver and other metals is used. The sheet resistance value of the conductive mesh is preferably in the range of 0.01 to 10Ω / □.

  As the pattern shape of the conductive mesh used in the present invention, a lattice shape, a polygon having five or more pentagons, a circle, or a combination thereof can be used. The line width of the conductive mesh is preferably 5 to 30 μm, more preferably 5 to 20 μm, and particularly preferably 5 to 15 μm. The distance between the lines is preferably in the range of 100 to 500 μm, more preferably in the range of 150 to 400 μm, and particularly preferably in the range of 200 to 350 μm. 1-20 micrometers is preferable and, as for the thickness of a conductive mesh, 2-15 micrometers is more preferable.

  Next, a method for producing a conductive mesh will be described. As one method, a metal foil laminated resin film obtained by bonding a metal foil such as a copper foil to a resin film such as a plastic film via an adhesive is used to form an etching resist pattern using a photolithographic method, a screen printing method, or the like. There is a method of etching the metal foil after the production. Etching methods include chemical etching methods. Chemical etching is a method in which unnecessary conductors other than the conductor part protected by an etching resist are dissolved and removed with an etching solution. Examples of the etching solution include a ferric chloride aqueous solution, a cupric chloride aqueous solution, and an alkaline etching solution.

  In the photolithographic method, a photosensitive layer that is exposed by irradiation with ultraviolet rays or the like is provided on a metal foil of a metal foil laminated resin film, and imagewise exposure is performed on the photosensitive layer using a photomask or the like previously processed into the pattern of the present invention. And developing to form a resist image, then etching the metal foil to form a conductive mesh pattern, and finally stripping the resist.

  The screen printing method is a method in which an etching resist ink is pattern-printed on the surface of the metal foil of the metal foil laminated resin film, cured, an electroconductive mesh is formed by an etching process, and then the resist is peeled off.

  Another method for producing the conductive mesh of the present invention includes a method using a photosensitive silver salt. In this method, a laminated film in which a silver salt emulsion layer such as silver halide is coated on a transparent substrate such as a plastic film is exposed through a photomask processed into the pattern of the present invention, or the pattern is digitized by a laser. In this method, a silver mesh pattern is formed by exposure and development. The formed silver mesh is preferably further plated with a metal such as copper or nickel. These methods are described in WO 2004/7810, JP-A No. 2004-221564, JP-A No. 2006-12935, and the like.

  In the present invention, the conductive mesh is preferably blackened. The blackening treatment can be performed by oxidation treatment or black printing. For example, the methods described in JP-A-10-41682, JP-A-2000-9484, 2005-317703 and the like can be used. The blackening treatment is preferably performed on the surface and both side surfaces on the viewing side of the mesh pattern, and it is preferable to perform blackening treatment on both surfaces and both side surfaces of the conductive mesh.

  The electromagnetic wave shielding layer made of a conductive mesh needs to be processed into a mesh pattern at least in the area corresponding to the image display area of the display, but the periphery of the image display area does not need to be processed in the mesh pattern. It may be left as it is. However, in order to efficiently manufacture a display filter on a continuous production line, the electromagnetic wave shielding layer is preferably a continuous mesh. The continuous mesh means that the mesh pattern is formed without interruption. For example, when a laminate having at least an electromagnetic wave shielding layer is produced in the form of a long roll, the mesh is continuously in the winding direction of the roll. It is formed. By using such a continuous mesh, when a laminate roll is cut to produce a sheet-like display filter, yield and productivity are improved.

  The optical functional film used in the present invention is a resin film such as a plastic film provided with an antireflection layer or an antiglare layer. These layers are preferably arranged so as to be the outermost surface on the viewing side (viewing side) when the display filter is mounted on the display.

  The antireflection layer has a function of preventing reflection or reflection of outside light. As the antireflection layer, a layer in which two or more layers of a high refractive index layer and a low refractive index layer are laminated in this order is used. The film thickness of the element can be determined. As antireflection properties, the visible light reflectance of the surface is preferably 3% or less.

The refractive index of the low refractive index layer is preferably less than 1.50, more preferably 1.45 or less. Examples of the material for forming the low refractive index layer include organic materials such as fluorine-containing polymers, (meth) acrylic acid partial or fully fluorinated alkyl esters, fluorine-containing silicones, and inorganic materials. MgF ₂ , CaF ₂ , SiO _{2 and the} like. The thickness of the low refractive index layer is preferably 1 μm or less, and more preferably 0.5 μm or less.

The refractive index of the high refractive index layer is preferably 1.5 or more, and more preferably 1.6 or more. Materials for forming the high refractive index layer include those obtained by polymerizing and curing urethane (meth) acrylate, polyester (meth) acrylate, etc., and by crosslinking and curing silicon-based, melamine-based, and epoxy-based crosslinkable resin raw materials. And organic materials such as copper, or those containing indium oxide as a main component and containing a small amount of titanium dioxide or the like, or inorganic materials such as Al ₂ O ₃ , MgO, and TiO ₂ . The thickness of the high refractive index layer is preferably 50 μm or less, and more preferably 10 μm or less.

  The antiglare layer refers to a film having a minute uneven surface state, in which particles are dispersed in a thermosetting or photocurable resin and applied and cured on a support, or a thermosetting type or A photo-curing resin is used on the surface, and a mold having a desired surface state is pressed onto the surface to form irregularities, and then cured. The antiglare property of the antiglare layer is preferably a haze value of 0.5 to 20%. An antiglare function may be imparted to the antireflection layer, or an antireflection function may be imparted to the antiglare layer.

  The display filter of the present invention preferably has a near infrared shielding function or an orange light shielding color tone function. As the near-infrared shielding function, the maximum value of light transmittance in the wavelength range of 800 to 1100 nm is preferably 15% or less. The near-infrared shielding function can be imparted, for example, by containing a near-infrared absorbing dye. Examples of such near infrared absorbing dyes include phthalocyanine compounds, anthraquinone compounds, dithiol compounds, diimonium compounds, and the like.

  As the orange light shielding color tone function, it is preferable that the minimum value of the light transmittance in the wavelength range of 580 to 610 nm is 30% or less. The orange light shielding color tone function can be imparted by including an orange light absorbing dye. As the orange light absorbing dye, a known dye or pigment having a desired absorption wavelength is used.

  As a method of including a near infrared absorbing dye or an orange light absorbing dye, a method using a plastic film in which the dye is kneaded, dispersed, or dissolved, or a paint in which the dye is kneaded, dispersed or dissolved in a resin or the like is provided on the support. There are a method of applying to the surface and a method of using an adhesive material in which a pigment is kneaded, dispersed and dissolved. Moreover, you may use combining these methods.

  Next, although the structural example of the filter for displays of this invention is shown below, this invention is not limited to these.

a) Adhesive layer / plastic film / adhesive layer / electromagnetic wave shielding layer / adhesive layer / plastic film / antireflection layer (antiglare layer)
b) Adhesive layer / plastic film / electromagnetic wave shielding layer / adhesive layer / plastic film / antireflection layer (antiglare layer)
c) Adhesive layer / electromagnetic wave shielding layer / adhesive layer / plastic film / antireflection layer (antiglare layer)
d) Adhesive layer / electromagnetic wave shielding layer / plastic film / antireflection layer (antiglare layer)
e) Adhesive layer / electromagnetic wave shielding layer / adhesive layer / near infrared shielding layer / plastic film / antireflection layer (antiglare layer)
f) Adhesive layer / plastic film / adhesive layer / electromagnetic wave shielding layer / adhesive layer / near infrared shielding layer / plastic film / antireflection layer (antiglare layer)
g) Adhesive layer / near infrared shielding layer / plastic film / electromagnetic wave shielding layer / adhesive layer / plastic film / antireflection layer (antiglare layer).

  In the above configuration, the near-infrared shielding layer may be provided as an independent layer as in e), f) and g), or the near-infrared shielding performance is imparted to the plastic film, the adhesive layer or the adhesive layer. May be. Similarly, the orange light shielding color tone function may be provided as an independent layer, or this function may be imparted to a plastic film, an adhesive material layer, or an adhesive material layer. Further, the surface layer may be an antireflection layer, an antiglare layer, or a layer having both functions.

  Further, it is preferable to provide a hard coat layer between the plastic film and the antireflection layer (antiglare layer). As the hard coat agent for forming the hard coat layer, for example, a thermosetting crosslinked resin mainly composed of an organosilicon compound, an epoxy resin, a melamine resin, or the like, or two or more (meth) acryloyloxy per molecule. Examples thereof include an active energy ray-curable crosslinkable resin having a group.

  The display filter of the present invention can be directly attached to the display panel with the adhesive layer in the above configuration example, but is mounted via a known high-rigidity substrate such as a glass plate, an acrylic plate, or a polycarbonate plate. You can also

  When the display filter of the present invention is directly bonded to a display panel, the pressure-sensitive adhesive layer in the above configuration example preferably has a function as an impact relaxation layer. In order to impart an impact relaxation function to the adhesive layer, the thickness of the adhesive layer is preferably 100 μm or more, more preferably 300 μm or more, and particularly preferably 500 μm or more. The upper limit thickness is preferably 3000 μm or less in consideration of the coating suitability of the pressure-sensitive adhesive layer. Examples of the adhesive material include acrylic resins, epoxy resins, urethane resins, silicone resins, rubber resins, and the like.

  The electromagnetic wave shielding layer may be laminated directly on a transparent substrate such as a plastic film (with only a primer layer for easy adhesion), laminated via an adhesive or adhesive, or adhesive. The form embedded in the material layer or the adhesive layer is mentioned. As the transparent substrate, a plastic film having a thickness of 30 to 300 μm is preferably used. For example, polyester resin, acrylic resin, polycarbonate resin, polyethylene naphthalate resin, polyethylene terephthalate resin, triacetyl cellulose, arton resin, epoxy resin, Examples thereof include plastic films such as polyimide resin, polyetherimide resin, polyamide resin, polysulfone, polyphenylene sulfide, and polyethersulfone.

  Examples of the adhesive material include acrylic, silicon, urethane, polyvinyl butyral, and ethylene-vinyl acetate. Adhesives include bisphenol A type epoxy resins, tetrahydroxyphenylmethane type epoxy resins, novolac type epoxy resins, resorcin type epoxy resins, polyolefin type epoxy resins and other epoxy resins, natural rubber, polyisoprene, poly-1, 2- (Di) enes such as butadiene, polyisobutene, polybutene, poly-2-heptyl-1,3-butadiene, poly-1,3-butadiene, polyoxyethylene, polyoxypropylene, polyvinyl ethyl ether, polyvinyl hexyl ether, etc. Polyesters such as polyethers, polyvinyl acetate, polyvinyl propionate, polyurethane, ethyl cellulose, polyvinyl chloride, polyacrylonitrile, polymethacrylonitrile, polysulfone, phenoxy resin And so on. The thickness of the adhesive layer or the adhesive layer is preferably 0.01 to 0.1 mm.

  Next, a method for manufacturing a display filter will be described. The production method of the present invention continuously bonds at least two strips under reduced pressure, and detects bubbles in the laminate obtained by bonding under reduced pressure. Bubbles are detected by irradiating light from one side of the continuously traveling laminate and determining the ratio of the diffused light component to the total transmitted light transmitted through the laminate. That is, since the ratio of the diffused light component increases as the amount of bubbles mixed in increases, the state of mixed bubbles in the laminate can be monitored in real time by measuring the ratio of the diffused light component to the total transmitted light.

  In the method for manufacturing a filter for display according to the present invention, as a band before bonding, an adhesive film, a plastic film, a metal foil for forming an electromagnetic wave shielding layer, an optical function having an antireflection layer or an antiglare layer Examples thereof include a conductive film and a plastic film in which a conductive mesh is laminated as an electromagnetic wave shielding layer (film with a conductive mesh).

  The production method of the present invention is suitable for laminating two strips via an adhesive or an adhesive, and is beneficial when the laminating surface of at least one strip is rough. is there. In particular, a film with a conductive mesh in which a conductive mesh is provided on a plastic film has an uneven surface due to the presence of the conductive mesh. This film with a conductive mesh and other strips (for example, optical functions) When an adhesive film is bonded via an adhesive material, air remaining in the recesses of the conductive mesh is present as bubbles in the adhesive material layer or at the bonding interface, thereby reducing the transparency of the laminate. Therefore, it is possible to greatly suppress the mixing of bubbles by pasting the rough strips as described above under reduced pressure.

  The preferable aspect of the manufacturing method of the filter for displays of this invention is the method of bonding a film with an electroconductive mesh, and an optical functional film through an adhesive material. In this case, it is preferable to use a belt-like body in which an adhesive material layer is laminated in advance on a bonding surface (an opposite surface such as an antireflection layer) of the optical functional film. Furthermore, it is preferable that a peelable cover film is previously laminated on the surface of the antireflection layer (antiglare layer) of the optical functional film. The cover film is provided to protect the antireflection layer, which is a surface layer, and is peeled off before or after mounting the display filter on the display.

  The back surface of the film with the conductive mesh (the surface opposite to the conductive mesh) may be preliminarily laminated with an adhesive layer for bonding to the display, or the film with the conductive mesh and the optical functional film may be pasted. After bonding, an adhesive layer may be laminated on the back surface of the film with conductive mesh.

  In this invention, it is preferable that a strip | belt-shaped body is supplied in roll shape, and the laminated body obtained by bonding is wound up in roll shape. It is preferable to detect the air bubbles in the laminate obtained by pasting, after the pasting and before winding up into a roll. In the present invention, at least the bonding step and the bubble detection step are performed under reduced pressure, but it is preferable to perform unwinding of the roll-shaped strip, bonding, bubble detection, and winding of the laminate under reduced pressure. That is, it is preferable to perform the above series of steps in a decompression chamber (decompression chamber).

  The degree of decompression is appropriately set according to the width of the belt-like body, the surface shape of the bonding surface (rough surface state), the bonding speed, etc. In the case of the display filter targeted by the present invention, 15 kPa or less. Preferably, 10 kPa or less is more preferable, and 7 kPa or less is particularly preferable. The lower the degree of decompression, the more air bubbles can be suppressed.However, considering the increase in equipment cost for decompression and the decrease in productivity due to the longer time to reach the set pressure, A lower limit of about 1 kPa is appropriate.

  The method for detecting bubbles in a laminate used in the present invention is performed by irradiating the laminate with light and measuring the ratio of the diffused light component to the total transmitted light transmitted through the laminate. If there are bubbles inside the laminate, the light passing through the laminate strikes the bubbles and diffuses (scatters), so the amount of bubbles mixed in is quantitatively measured by measuring the ratio of the diffused light component to the total transmitted light. Can be requested.

  For the ratio of the diffused light component to the total transmitted light transmitted through the laminate in the present invention, for example, a measurement method based on measurement of haze value (JIS K7105; 1981 edition) can be used. Measure parallel light transmittance (Tp) and diffused light transmittance (Td) of the laminate with a haze meter, and obtain the value (transmitted light diffusivity) given by [Td / (Tp + Td)] × 100 (%) Can do.

  As a light source for irradiating the laminate with light, a C light source or a D65 light source is preferably used. The light receiving unit that receives light transmitted through the laminate and measures the transmitted light diffusivity has an integrating sphere. A light source is installed so that light may be irradiated to a laminated body perpendicularly. The light receiving unit is also installed so that the light receiving direction is perpendicular to the stacked body. Both the light source and the light receiving unit are installed in a non-contact state on the laminate. The light receiving part is preferably brought close to the laminated body in a non-contact state. However, if the light receiving part is too close, there is a risk that the light receiving part and the laminated body come into contact with each other to cause scratches on the laminated body. -20 mm is suitable, and the range of 3-10 mm is preferable.

  The bubble detection means of the present invention may be composed of a pair of light sources and a light receiving unit, may be composed of a plurality of pairs of light sources and a light receiving unit, or may be composed of a plurality of light receiving units and one movable light source. It may be constituted by. Which configuration is adopted is appropriately selected according to the width of the laminate.

  As in the present invention, a nip roll is suitable as a laminating means in a method of continuously laminating a belt-like body, but in the case of laminating with a nip roll, the nip pressure is low at the center in the width direction. This tends to cause air bubbles to be mixed into the center. Therefore, it is preferable to arrange the bubble detection means in the vicinity of the central portion of the laminated body. In addition, it is more preferable to dispose bubble detecting means in the vicinity of the central portion and the end portion.

  In the production method of the present invention, the laminating speed (line speed) of the strip is preferably 10 m / min or less, more preferably 8 m / min or less, from the viewpoint of the accuracy of bubble detection. From the viewpoint of productivity, it is preferably 1 m / min or more, and more preferably 2 m / min or more. The width of the strip used in the present invention is preferably 50 to 150 cm, and the winding length of the strip is preferably 300 to 2000 m.

  Next, a manufacturing apparatus for carrying out the manufacturing method of the present invention will be described. Such a manufacturing apparatus includes a decompression chamber, unwinding means for holding and unwinding at least two roll-shaped strips in the decompression chamber, and pasting means for pasting at least two strip-shaped bodies. , A winding means for winding up the laminated body obtained in a roll shape, and a bubble detection means arranged between the bonding means and the winding means, and the bubble detection The means has a light source and a light receiving portion with the laminate interposed therebetween, and the light receiving portion has means for obtaining a ratio of the diffused light component to the total transmitted light transmitted through the laminate.

  The manufacturing apparatus will be specifically described with reference to the drawings. FIG. 1 is a schematic view showing an embodiment of the production apparatus of the present invention. Such a manufacturing apparatus includes unwinding shafts 3 and 4 for holding and unwinding the roll-shaped strips 1 and 2, nip rolls 5 and 6 for continuously laminating the traveling strip-shaped bodies, and a laminate 11. The bubble detection means 7 and the take-up shaft 8 for taking up the laminated body 11 in a roll shape are installed in the decompression chamber 21. The decompression chamber 21 is maintained in a vacuum state (1 to 15 kPa) by decompression means (for example, a vacuum pump) (not shown). The take-up shaft 8 is driven and rotated by a driving means (not shown), while the unwinding shafts 3 and 4 are inhibited from rotating by a rotation restraining means (brake), whereby the unwinding shafts 3 and 4 and the take-up shaft 8 are rotated. The tension between is adjusted.

  In the roll-shaped strip 1, an adhesive material layer is previously laminated on the bonding surface, and a separate film take-up shaft 9 for winding up the separate film 12 is installed to be drivable. Similarly, a take-up shaft 10 for taking up the separate film 13 is also provided on the roll-shaped strip 2 side.

  The bubble detection means 7 includes a light source unit 7 a and a light receiving unit 7 b, and the light source unit 7 a and the light receiving unit 7 b are arranged so as to sandwich the stacked body 11. The light receiving unit 7b receives the light transmitted through the stacked body 11, and measures the ratio of the diffused light component to the total transmitted light. As the light source of the light source unit 7a, a C light source or a D65 light source is preferably used. The light source unit 7a further includes a lens and a diaphragm. Although not shown in detail, the light receiving unit 7b is composed of an integrating sphere, a standard white plate, a light trap, and the like, and the ratio of the diffused light component to the total transmitted light is obtained by these.

  As described above, the bubble detection method of the present invention can employ, for example, a measurement method based on the measurement principle of haze value (JIS K7105; 1981 edition), and therefore a commercially available haze meter can be applied with slight changes. It is. For example, the haze meter “Haze Guard II” marketed by Toyo Seiki Co., Ltd. is separated from the light source part and the light receiving part and arranged on both sides of the laminate, or at the end of the laminate. By arranging as it is, detection targeted by the present invention can be performed.

  Data (transmitted light diffusivity) measured by the light receiving unit 7 b is displayed in real time on the display device 22 arranged outside the decompression chamber 21. The display device 22 is programmed with a monitoring function of measurement data, and includes a warning means (for example, a warning buzzer) for notifying the operator when a predetermined management width (upper limit value) is exceeded.

  In the manufacturing apparatus of the present invention, although not shown, the degree of decompression, the nip pressure of the pair of nip rolls, and the line speed (conveying speed) are also provided outside the decompression chamber. Thereby, the degree of decompression, the nip pressure, and the line speed can be monitored with the set management width. However, in actual manufacturing, it may be temporarily out of the above-mentioned control range, and it is necessary to determine whether or not a single defect has occurred, but the manufacturing method of the present invention determines online in real time. It is extremely useful in that it can be done.

  In addition, bubbles may be mixed due to factors other than the manufacturing conditions as described above, for example, fluctuations in the adhesiveness of the adhesive material, the thickness profile of the strip, the surface shape of the conductive mesh, and the like. The present invention is also effective in detecting bubble contamination due to factors other than such manufacturing conditions.

  The display filter targeted by the present invention is suitable as a front filter for a plasma display. The front filter needs to be grounded by connecting the electromagnetic wave shielding layer in the filter and the external electrode of the display body. Since an insulating optical functional film is usually laminated on the electromagnetic shielding layer, conventionally, an optical functional film having a size smaller than that of the electromagnetic shielding layer is bonded, and the electromagnetic shielding layer on the outer periphery of the filter is exposed. Thus, forming a frame-shaped electrode has been performed. This method must be bonded after cutting the electromagnetic wave shielding layer (film with a conductive mesh) and the optical functional film into a sheet of a predetermined size in advance, and can be applied to continuous bonding with a strip. There wasn't.

  When continuously laminating with a belt-like body, the width of the optical functional film is made smaller than the width of the electromagnetic wave shielding layer (film with conductive mesh), so that the above-described electromagnetic wave shielding layer is exposed on the two opposite sides in the width direction. However, for the two sides corresponding to the transport direction (winding direction) at the time of manufacture, it is impossible to obtain an electrode with an electromagnetic wave shielding layer exposed in advance. It is necessary to form an electrode.

  Therefore, the roll-like laminate (display filter) obtained by the production method of the present invention needs to form electrodes on at least two sides corresponding to the winding direction before or after cutting into a sheet of a predetermined size. Yes, a preferred method of electrode formation will be described below.

  A preferable method of forming an electrode used in the present invention is that an optical function is applied to at least two opposing ends of the rectangular display filter (corresponding to the outer periphery of the image display area when mounted on the display panel of the display). This is a method of exposing the electromagnetic wave shielding layer by irradiating a laser from the conductive film side to form at least a gap reaching the electromagnetic wave shielding layer. The exposed portion of the electromagnetic wave shielding layer becomes an electrode. The gap is preferably provided in a straight line parallel to the side. The air gap may be a straight groove shape or may be formed discontinuously in a straight line shape. The total length of the gaps per side is preferably 20% or more, more preferably 30% or more, particularly from the viewpoint of obtaining high grounding efficiency and maintaining the strength of the filter. 50% or more is preferable. The upper limit is preferably 95% or less, and more preferably 90% or less. The width of the gap is preferably a width that can be formed by scanning the laser once, that is, the opening width of the surface is preferably about 0.5 to 3 mm, and more preferably 0.5 to 2 mm.

Examples of the laser used for forming the void include iodine, YAG, CO _{2 and the} like. Among these, a CO ₂ laser is preferably used. In the case of forming a void with a laser, the organic matter in the portion irradiated with the laser dissolves, evaporates, or burns, so that the void is formed only by irradiating the display filter with the laser. Therefore, compared to the method in which a display filter is cut and a part of the display filter is peeled off along the cut, the method of directly forming a void with a laser does not require a peeling step, which is beneficial for improving productivity. is there.

  The air gap can be provided in all the ends of the four sides of the rectangular display filter. This is because when an electromagnetic wave shielding layer (film with a conductive mesh) of the same width is bonded to an optical functional film, or a laminate having a size capable of removing a plurality of sheet-like filters in the width direction of the laminate is manufactured. Applies to

  In the present invention, it is preferable that the gap is further filled with a conductor such as a conductive paste. As the conductive paste, a metal paste containing silver, gold, palladium, copper, indium, tin, an alloy of silver and other metals is preferable because high conductivity is obtained.

  In the present invention, a preferred embodiment for forming an electrode on a display filter includes an optical functional film with a cover film in which a cover film for protecting the optical functional film is laminated in advance and a film with a conductive mesh. Before or after the roll-shaped laminate obtained by laminating by the production method of the invention is cut into a sheet of a predetermined size, a void is formed from above the cover film by the above-described method, and the void is electrically conductive. An electrode is formed by filling a conductor such as a paste. Since the cover film is peeled off before or after the display filter is attached to the display, an electrode protruding from the surface of the display filter is formed by forming the electrode from above the cover film. The conduction with the electrode becomes stable and reliable.

  Various plastic films can be used as the cover film. For example, polyester films such as polyethylene terephthalate, polyolefin films such as polyethylene film, polypropylene film, polybutylene film, polyacetylcellulose film, polyacryl film, polycarbonate film, epoxy film, polyurethane film, etc. A film or a polyolefin film is preferably used. 20-200 micrometers is suitable for the thickness of a cover film, and 30-100 micrometers is preferable.

  Since the cover film is finally peeled and removed from the flat display member, a peelable adhesive or adhesive is used. Or when using the film which has adhesiveness as a cover film, an adhesive material etc. are unnecessary.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these Examples.

<Example 1>
A cover film, an optical functional film, and a belt-like adhesive material shown below were bonded together to obtain a belt-like body 1 (cover film / optical functional film / adhesive material layer / separate film).
<Cover film>
“E-MASK IP300” manufactured by Nitto Denko Co., Ltd .; a laminate of 5 μm slightly adhesive layer on 38 μm PET film.
<Optical functional film>
“Clearus (registered trademark)” manufactured by Sumitomo Osaka Cement Co., Ltd .; a film having an antireflection layer as a surface layer on a PET film having a thickness of about 100 μm and a near-infrared shielding layer on the surface opposite to the antireflection layer.
<Adhesive layer>
Acrylic tone adhesive "TD43A" manufactured by Yodogawa Paper Co., Ltd .; with separate film.

  Next, the belt-like body 2 was created by the method shown below.

  A copper foil film in which a copper foil having a thickness of about 10 μm is laminated on a PET film having a thickness of about 125 μm via an adhesive layer is subjected to an etching resist pattern forming method using a photolithographic method. A film with a conductive mesh on which a grid-like conductive mesh (electromagnetic wave shielding layer) of about 250 μm was formed was obtained. In addition, the separate film is laminated | stacked on the electroconductive mesh surface of the film with an electroconductive mesh.

  The widths of the strips 1 and 2 produced above are 550 mm and 570 mm, and the winding length is 1000 m, respectively.

  Next, it bonded together using the manufacturing apparatus of FIG. 1 so that the width direction centerline of the strip | belt-shaped body 1 and the strip | belt-shaped body 2 might correspond. The production conditions were set to a line speed (conveyance speed) of 4 m / min, a degree of vacuum of 5 kPa, and a nip pressure of 5 kg / cm. When the strips 1 and 2 are unwound, the separate film is peeled off, and the adhesive material layer surface of the strip 1 and the conductive mesh surface of the strip 2 are bonded together by a nip roll pair to obtain a laminate. The obtained laminate is wound into a roll after the ratio of the diffused light component to the total transmitted light is measured by the bubble detection means. The data measured by the bubble detection means was displayed on the display device in real time, and the alarm buzzer sounded when the preset upper limit value was exceeded.

  In this example, a light source part and a light receiving part of a haze meter “Haze Guard II” marketed by Toyo Seiki Co., Ltd. as bubble detection means were separated and placed at the center of both sides of the laminate. The light source unit is set at 20 mm from the laminate and the light receiving unit is set at an interval of 5 mm from the laminate, and the upper limit of the ratio of the diffused light component to the total transmitted light is set to 3%. I made it.

  The production apparatus of FIG. 1 was operated under the above production conditions to produce 300 m of the laminate, but the alarm buzzer never sounded. Subsequently, the degree of decompression was lowered step by step while continuously operating, and when the alarm buzzer sounded, the alarm buzzer sounded when the degree of decompression was around 13 kPa. When the laminated body where the alarm buzzer sounded was sampled and observed with a microscope, microbubbles having a diameter of about 10 to 50 μm were present in the recesses of the conductive mesh. On the other hand, mixing of bubbles was not observed in the laminate where the alarm buzzer did not sound.

  As can be seen from this example, the production method and the production apparatus of the present invention can accurately detect in real time the mixing of bubbles in continuous bonding under reduced pressure, thereby reducing the amount of defective products generated. It can be stopped to a minimum.

  Next, on the film side with the conductive mesh of the obtained laminate, a UV curable urethane acrylate resin (“Hybon (registered trademark)” manufactured by Hitachi Chemical Polymer Co., Ltd.) is used in a production line different from the above production process. )) With a slot die coater so that the thickness was 250 μm. After coating, the coating film was cured using a UV irradiation device, and then a separate film (“Therapel (registered trademark)” manufactured by Toray Film Processing Co., Ltd., thickness 38 μm) was attached.

The roll laminate thus produced was cut into a length of 980 mm to obtain a display filter having a predetermined size. Subsequently, the display filter is fixed to a laser cutter (Comax laser cutter, CO ₂ laser head, maximum output 200 W), and the laser is linearly formed with a length of 530 mm 7 mm inward from the short side end of the display filter. To form voids. The laser head speed was set to 1300 cm / min, the laser output and the focal position were adjusted to form a gap that penetrated the conductive mesh from the cover film surface to the PET film. The width of the gap was 1 mm at the surface opening portion and 0.4 mm at the conductive mesh portion. Furthermore, a conductive paste (“Dotite (registered trademark)” manufactured by Fujikura Kasei Co., Ltd.) was applied to the voids with a dispenser, and dried in a hot air oven to form an electrode. On the long side of the display filter, the electromagnetic shielding layer (conductive mesh) is exposed with a width of about 10 mm from the end, and the exposed portion serves as an electrode.

  The display filter thus produced is assembled to the casing of the plasma display after the separation film is peeled off and attached to the display panel of the plasma display, the cover film is peeled off and removed.

Schematic diagram of the manufacturing apparatus of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 Strip body 3, 4 Unwinding shaft 5, 6 Nip roll 7 Bubble detection means 8 Winding shaft 11 Laminated body 21 Depressurization chamber

Claims (6)

  A method for producing a transparent laminate, the step of continuously laminating at least two strips to obtain a laminate, and the total transmission through which the laminate traveling continuously is irradiated with light and transmitted through the laminate And a step of measuring a ratio of a diffused light component to light. At least the two steps are performed under reduced pressure.   The manufacturing method of the laminated body of Claim 1 with which the bonding of the said strip | belt body is performed via an adhesive material or an adhesive material.   The method for producing a laminate according to claim 1 or 2, wherein one of the strips has a conductive mesh on a plastic film.   The method for producing a laminate according to claim 3, wherein the other of the strips has an antireflection layer or an antiglare layer on a plastic film.   The said laminated body is a filter for a display, The manufacturing method of the laminated body of any one of Claims 1-4.   An apparatus for producing a transparent laminate, wherein a decompression chamber, unwinding means for holding and unwinding at least two roll-shaped strips in the decompression chamber, and at least two strips are bonded together Bonding means for winding, a winding means for winding the laminated body obtained in a roll shape, and a bubble detection means arranged between the bonding means and the winding means The bubble detecting means has a light source part and a light receiving part arranged with a laminated body interposed therebetween, and the light receiving part has a means for obtaining a ratio of a diffused light component to a total transmitted light transmitted through the laminated body. Body manufacturing equipment.

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