TWI729163B - Manufacturing method of optical display panel and manufacturing system of optical display panel - Google Patents

Abstract

The object of the present invention is to provide a method for manufacturing an optical display panel, which can appropriately manufacture optical display panels with the same structure even when a roll-to-panel method and a sheet-to-panel method are used in combination when a thin optical functional film is attached to an optical unit. Display panel. The manufacturing method of the optical display panel of the present invention includes the following steps: a first panel manufacturing step, which uses a rolled optical film to attach an optical film to one surface of an optical unit; and a second panel manufacturing step, which is based on optics A single-piece optical film is attached to one side of the unit. The second panel manufacturing step includes the following steps: peeling the release film from the monolithic optical film that is structured as laminated release film, adhesive layer, optical function film, first surface protection film, and second surface protection film, and The single-piece optical film is attached to one surface of the optical unit through the exposed adhesive layer, and the second surface protection film is peeled from the single-piece optical film in the state of being attached to the optical unit.

Description

Manufacturing method of optical display panel and manufacturing system of optical display panel

The present invention relates to a manufacturing method of an optical display panel and a manufacturing system of the optical display panel.

There are methods for attaching the optical film to the optical unit: an optical film system composed of a release film, an adhesive layer, an optical function film (typically a polarizing film), and a surface protection film are laminated in a roll shape. The optical film sent from the roll of optical film is cut in the width direction (half-cut) of the adhesive layer, optical function film and surface protection film while leaving the release film, and the release film is cut from the The obtained optical film is peeled off, and the optical film is bonded to the optical unit via the exposed adhesive layer (hereinafter also referred to as "roll-to-panel method") (for example, refer to Patent Documents 1 and 2).

On the other hand, an optical film bonding method that is different from the roll-to-panel method has the following method: the optical film previously prepared in a single sheet state is bonded to the optical unit through the adhesive layer that has been peeled off the release film and exposed. Hereinafter, it is also referred to as a "sheet-to-panel method") (for example, refer to Patent Document 3).

Prior Art Documents Patent Documents Patent Document 1: Japanese Patent Application Publication No. 2011-123208 Patent Document 2: Japanese Patent Application Publication No. 2015-049115 Patent Document 3: Japanese Patent Application Publication No. 2006-039238

The problem to be solved by the invention The current situation of optical display panel manufacturing plants is that most of them have sheet-to-panel manufacturing equipment, while roll-to-panel manufacturing equipment is scarce.

In recent years, with the development of thinning of optical display panels, the development of thinner optical function films (for example, polarizing films with a thickness of 60 μm or less), including polarizing films, has continued. Such thin optical functional films have low toughness (modulus of elasticity) and are prone to distortion and warpage. Therefore, the existing sheet material may not be able to respond to the manufacturing equipment of the panel method.

In addition, in the manufacturing sites of optical display panels such as liquid crystal display panels, it has recently emerged that not only the roll-to-panel method but also the sheet-to-panel method are used to manufacture optical display panels of the same structure. For example, Patent Document 2 discloses that an optical display panel is continuously manufactured using a roll-to-panel method, and the optical display panel that has been determined to be defective is subjected to rework processing. In the case that defective products do not occur so often, it is conceivable to use a sheet-to-panel method when laminating a new optical functional film on the optical unit in the heavy industry process. For another example, when it is necessary to mass-produce optical display panels of the same structure in a short time, it is also conceivable that the sheet-to-panel method will be used in combination when the roll-to-panel method cannot supply the full supply amount.

However, as mentioned above, since the thinner the optical film, the more likely it is to be warped and warped. Therefore, in the sheet-to-panel method, the transport of the single-piece optical film, the peeling of the release film, and the pairing of the optical function film Operations such as the bonding process of the liquid crystal cell become difficult, and therefore the yield rate may be significantly lowered.

The object of the present invention is to provide a method for manufacturing an optical display panel, which can appropriately manufacture optical display panels with the same structure even when a roll-to-panel method and a sheet-to-panel method are used in combination when a thin optical functional film is attached to an optical unit. Display panel.

Means to Solve the Problem The present invention is a method of manufacturing an optical display panel, which includes the following steps: The first panel manufacturing step, including the first attaching step, is a roll-shaped optical film wound by a ribbon-shaped optical film , Attaching the optical film to at least any side of the optical unit to form an optical display panel; and the second panel manufacturing step, including a second attaching step, which is to attach a single-piece optical film to at least any side of the optical unit An optical display panel is formed; wherein, the first attaching step is: output from the roll-shaped optical film and the structure is sequentially laminated with a release film, an adhesive layer, an optical function film, and a first surface protection film The strip-shaped optical film peels off the release film, and attaches the optical film to at least any one surface of the optical unit through the exposed adhesive layer; the second attaching step is: stacking sequentially from the structure The single-piece optical film having the release film, the adhesive layer, the optical function film, the first surface protection film, and the second surface protection film peels off the release film, and removes it through the exposed adhesive layer The single-piece optical film is attached to at least any one surface of the optical unit; and, the second panel manufacturing step includes: a second surface protection film peeling step, which is from the state of being attached to the optical unit The single-sheet optical film peels off the second surface protection film.

In the above invention, the first attaching step may include the following step: a cutting step, which is a step of cutting the tape-shaped optical film output from the roll-shaped optical film while retaining the release film in the longitudinal direction of the optical film. Cutting in an orthogonal direction; and a peeling step of peeling the release film from the optical film.

In the above invention, the strip-shaped optical film may be formed with slits at predetermined intervals except for the release film, and the first attaching step may include a peeling step, which is to fold the release film back inward. The type film is peeled from the optical film output from the roll optical film.

Yet another invention is an optical display panel manufacturing system, including: a first panel manufacturing part, including a first attaching part, which is a roll-shaped optical film wound by using a ribbon-shaped optical film, and at least any part of the optical unit The optical film is attached to one side to form an optical display panel; and the second panel manufacturing part includes a second attachment part that is attached to at least any one side of the optical unit to form a single-piece optical film to form an optical display panel; wherein , The first attaching part is: peeling off the tape-shaped optical film that has been output from the roll-shaped optical film and has a structure in which a release film, an adhesive layer, an optical function film, and a first surface protective film are sequentially laminated Release film, and attach the optical film to at least any one surface of the optical unit through the exposed adhesive layer; The single-piece optical film of the adhesive layer, the optical function film, the first surface protection film, and the second surface protection film peels off the release film, and passes through the exposed adhesive layer to the single-piece optical film Attached to at least any one surface of the optical unit; and the second panel manufacturing section may have: a second surface protection film peeling section, which is from the single-piece optical film attached to the optical unit The second surface protection film is peeled off.

In the above invention, the first attaching portion may have: a cutting portion, which is a strip-shaped optical film output from the roll-shaped optical film, leaving the release film at an angle perpendicular to the longitudinal direction of the optical film Direction cut; and a peeling part, which peels the release film from the optical film.

In the above invention, the strip-shaped optical film may be formed with slits at predetermined intervals except for the release film, and the first attaching part may have a peeling part which is folded back inward to remove the release film. The type film is peeled from the optical film output from the roll optical film.

In the above invention, when a polarizing film is used as the optical function film, the first optical function film, the second optical function film, or the polarizing film is included as one of its structural members, the direction of the absorption axis of the strip-shaped polarizing film It may be parallel to the longitudinal direction, orthogonal to the longitudinal direction, or oblique (for example, a direction at an angle of 45° to the longitudinal direction). In addition, the direction of the absorption axis of the rectangular monolithic polarizing film may be parallel to the longitudinal direction, orthogonal to the longitudinal direction, or oblique (for example, a direction at an angle of 45° to the longitudinal direction). In addition, the direction of the absorption axis of the square monolithic polarizing film may be parallel to any one side and may be oblique (for example, a direction at an angle of 45° to one side).

In the present invention, the roll-shaped optical film can keep the release film, the adhesive layer, the optical function film and the surface protection film along the direction (width direction) orthogonal to the length direction of the optical film to correspond to the other of the optical unit. The gap between opposite sides of the group forms a slit. According to this structure, there is no need to cut (half-cut) the optical film in the roll-to-panel method.

In the above-mentioned invention, the aforementioned optical unit may be a VA type or IPS type liquid crystal unit or an organic EL unit.

The shape of the aforementioned optical unit only needs to be a shape having one set of opposite sides and another set of opposite sides, and may be square or rectangular, and is not particularly limited. In addition, generally speaking, one set of opposite sides of the optical unit and the other set of opposite sides are orthogonal to each other.

"Roll-to-panel method" is a method in which the release film is peeled from the optical film output from the roll optical film, and the optical film is bonded to the optical unit through the exposed adhesive layer. Here, until the release film is peeled off, the optical film may have slits with a predetermined interval under the release film in the width direction of the optical film. Cuts can be formed in the optical film before output, or cuts can be formed in the optical film after output and before the release film is peeled off.

The "sheet-to-panel method" is a method in which the release film is peeled from the optical film that has been previously made into a single sheet, and the optical film is bonded to the optical unit through the exposed adhesive.

Effect of the Invention The roll-shaped optical film is used to manufacture an optical display panel using a roll-to-panel method, and the structure of the optical display panel is that an adhesive layer, an optical function film, and a first surface protection are sequentially laminated on at least any side of the optical unit film. In addition, the single-sheet optical film provided with the second surface protection film has improved operability, so it is used to manufacture an optical display panel using a sheet-to-panel method while suppressing the occurrence of distortion, warpage, etc., and the optical display panel It is a structure in which an adhesive layer, an optical function film, and a first surface protection film are sequentially laminated on at least any surface of the optical unit. Then, the second surface protection film is removed (for example, peeled) from the single-sheet optical film bonded to the optical display panel. As a result, the sheet-to-panel method can still produce an optical display panel with the same layered structure as the optical display panel made by the roll-to-panel method.

<Optical film set> First, the optical film set used in the present invention will be described. Fig. 1 is a schematic diagram showing an optical film group. The upper part of FIG. 1 shows an enlarged cross-sectional view of the side, plane, and part of the first optical film 1 in a rolled form. The lower part of FIG. 1 shows an enlarged cross-sectional view of the side, plane and part of the single-piece first optical film 2. In the roll-shaped first optical film 1, a first release film 11, a first adhesive layer 12, a first optical function film 13, and a first surface protection film 14 are laminated in this order.

The roll-shaped first optical film 1 is used to manufacture an optical display panel by a roll-to-panel method. In this case, the strip-shaped first optical film 10 of the width a that has been output from the roll-shaped first optical film 1 is cut by the cutting means C at a predetermined interval b while leaving the release film 11. The symbol s is a slit formed by the above-mentioned cutting of the first optical film 10.

In addition, in the monolithic first optical film 2, a first release film 21, a first adhesive layer 22, a first optical function film 23, a first surface protection film 24, and a second surface protection film 25 are laminated in this order. The dimensions of the single sheet-shaped first optical film 2 are longitudinal a and lateral b. The monolithic first optical film 2 is used to manufacture an optical display panel by a sheet-to-panel method.

In this embodiment, the first release film 11 and the first release film 21 have the same structure. The first adhesive layer 12 and the first adhesive layer 22 have the same structure. The first optically functional film 13 and the first optically functional film 23 have the same structure. The first surface protection film 14, the first surface protection film 24, and the second surface protection film 25 have the same structure. The so-called "same structure" only needs to be substantially the same (for example, the same in manufacturing quality), and it is not only that the materials, thickness, etc. are completely the same.

In this embodiment, the first surface protection film 14 (or 24) has a first base film and a first adhesive layer, and is laminated on the first optical function film 13 (or 23) through the first adhesive layer. In addition, in another embodiment, the first surface protection film 14 (or 24) may also be a self-adhesive film.

In this embodiment, the second surface protection film 25 has a second base film and a second adhesive layer, and is laminated on the first surface protection film 24 through the second adhesive layer. In addition, in another embodiment, the second surface protection film 25 may be a self-adhesive film.

(Relationship of interlayer peeling force) In addition, structurally, the interlayer peeling force between the first surface protective film 24 and the first optically functional film 23 is greater than the interlayer peeling force between the second surface protective film 25 and the first surface protective film 24. Thereby, the second surface protection film 25 can be peeled off relatively smoothly. For the measurement of the peeling force, for example, a tensile tester can be used. Regarding the peeling conditions, the measurement was performed at 0.3 m/min 180° peeling. The peeling force is controlled by the composition or thickness of the adhesive.

The magnitude relationship of the peeling force between each layer in the single sheet-like first optical film 2 is as follows. Set as the interlayer peeling force A between the first release film 21 and the first adhesive layer 22, the interlayer peeling force B between the first adhesive layer 22 and the first optically functional film 23, the first optically functional film 23 and the first surface When the interlayer peeling force C of the protective film 24 and the interlayer peeling force D of the first surface protective film 24 and the second surface protective film 25 are A<B, A<C, A<D. And preferably A<D<C≦B, or A<D<B≦C. Preferably, A<D<C<B. According to the relationship of the above-mentioned interlayer peeling force, when the first release film is peeled off, the peeling of the second surface protection film can be suppressed.

<Optical Function Film> The first optical function films 13, 23 are not particularly limited as long as they are films with optical functions. Examples include polarizing films, retardation films, brightness enhancement films, diffusion films, etc. The representative ones are polarizing films .

(Polarizing film) From the viewpoint of thinning, it is preferable to use a polarizing film having a thickness (total thickness) of 60 μm or less, preferably 55 μm or less, and more preferably 50 μm or less. Examples of polarizing films include: (1) a structure in which protective films (also known as "polarizer protective film") are laminated on both sides of the polarizer (also known as "double-sided protective polarizing film"); (2) only on one side of the polarizer A structure in which a protective film is laminated (also known as a "single-side protective polarizing film"), etc.

(Polarizer) The polarizer is made of polyvinyl alcohol resin. Examples of polarizers include hydrophilic polymer films such as polyvinyl alcohol-based films, partially formalized polyvinyl alcohol-based films, and ethylene-vinyl acetate copolymer-based partially saponified films that adsorb iodine or dichroic dyes. Color materials and uniaxially stretched, and polyolefin-based alignment films such as dehydrated polyvinyl alcohol or dehydrated polyvinyl chloride. Among them, a polarizer composed of a polyvinyl alcohol-based film and a dichroic substance such as iodine is suitable.

A polarizer made of polyvinyl alcohol-based film dyed with iodine and then uniaxially stretched can be produced in the following way, for example: the polyvinyl alcohol film is dipped in an aqueous solution of iodine to dye, and then stretched to 3-7 of the original length Times. It can also be immersed in aqueous solutions such as boric acid or potassium iodide that may contain zinc sulfate or zinc chloride. Furthermore, if necessary, the polyvinyl alcohol-based film may be immersed in water for washing before dyeing. By washing the polyvinyl alcohol-based film with water, the dirt and anti-caking agent on the surface of the polyvinyl alcohol-based film can be cleaned. In addition, the polyvinyl alcohol-based film can be swollen, which also has the effect of preventing uneven dyeing. The extension can be performed after dyeing with iodine, or it can be extended while dyeing, or it can be dyed with iodine after extension. It can also be extended in aqueous solutions such as boric acid or potassium iodide or in a water bath.

From the viewpoint of thinning, the thickness of the polarizer is preferably 10 μm or less, preferably 8 μm or less, preferably 7 μm or less, and preferably 6 μm or less. On the other hand, the thickness of the polarizer is preferably 2 μm or more, more preferably 3 μm or more. Such a thin polarizer has few variations in thickness, excellent visibility (visibility), and low dimensional change, so it has excellent durability against thermal shock. On the other hand, a polarizing film containing a polarizer with a thickness of 10 μm or less has a significantly lower film toughness (modulus of elasticity), so that distortion, warping, etc. are likely to occur in the sheet-to-panel method. Therefore, the polarizing film in the present invention is particularly suitable.

As a thin polarizer, representative ones include Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014/077599, International Publication The thin polarizer described in the manuals such as the 2014/077636 manual, or the thin polarizer obtained by the manufacturing method described in the manual.

The aforementioned polarizer should be constructed so that its optical characteristics expressed by monomer transmittance T and polarization degree P satisfy the conditions of the following formula: P>-(10 ^0.929 T ^-42.4 -1)×100 (but T<42.3), or P≧99.9 (but T≧42.3). A polarizer configured to satisfy the aforementioned conditions will undoubtedly have the performance required for a liquid crystal television display using a large display element. Specifically, the contrast ratio is 1000:1 or more and the maximum brightness is 500cd/m2 or more. For other uses, for example, it can be attached to the viewing side of the organic EL unit.

As the aforementioned thin polarizer, in the manufacturing method including the stretching step and the dyeing step in the state of a laminate, in terms of high-magnification stretching and improved polarization performance, it is preferable to use the Japanese Patent No. 4751486 and the Japanese Patent As described in the specification No. 4751481 and the specification No. 4815544 of the Japanese Patent No. 4815544, the preparation method including the step of extending in an aqueous solution of boric acid is particularly preferably obtained by the specification of the specification No. 4751481 and the specification No. 4815544 contained in the boric acid. Obtained from the manufacturing method of performing auxiliary aerial stretching step before stretching in aqueous solution. These thin polarizers can be produced by a manufacturing method containing the following steps: the step of extending the polyvinyl alcohol resin (hereinafter also referred to as PVA resin) layer and the resin substrate for stretching in the state of a laminate and performing dyeing A step of. According to this manufacturing method, even if the PVA-based resin layer is thin, it can still be stretched and supported by the resin base material, so that it can be stretched without problems such as breakage caused by stretching.

(Protective film (polarizer protective film)) The material constituting the protective film is preferably one that is excellent in transparency, mechanical strength, thermal stability, moisture barrier properties, and isotropy. Examples include polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate; cellulose-based polymers such as cellulose diacetate and cellulose triacetate; acrylic acid such as polymethyl methacrylate -Based polymers; styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymer (AS resin); and polycarbonate-based polymers. In addition, the following polymers can also be cited as examples of polymers forming the above-mentioned protective film: polyethylene, polypropylene, polyolefins having cyclic or even norbornene structures, such as polyolefin polymerization of ethylene-propylene copolymers Compounds, chlorinated vinyl polymers, amide-based polymers such as nylon and aromatic polyamides, imine-based polymers, turbid polymers, polyether-based polymers, polyether ether ketone-based polymers, Polyphenylene sulfide polymer, vinyl alcohol polymer, chlorinated vinylidene polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer or the above-mentioned polymerization Blends of materials, etc.

In addition, the protective film may contain one or more arbitrary appropriate additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments, colorants, and the like. The content of the above-mentioned thermoplastic resin in the protective film is preferably 50-100% by weight, preferably 50-99% by weight, more preferably 60-98% by weight, and particularly preferably 70-97% by weight. In the transparent protective film, when the content of the thermoplastic resin is 50% by weight or less, the thermoplastic resin may not fully exhibit its inherent high transparency.

The aforementioned protective film can also use a retardation film, a brightness enhancement film, a diffusion film, and the like.

Functional layers such as hard coating, anti-reflection layer, anti-adhesion layer, diffusion layer and anti-glare layer can be provided on the surface of the aforementioned protective film that is not bonded to the polarizer. In addition, the above-mentioned functional layers such as the hard coat layer, the anti-reflection layer, the anti-adhesion layer, the diffusion layer, and the anti-glare layer can be provided on the transparent protective film itself, or can be provided separately from the transparent protective film and be another entity.

(Intermediate layer) The aforementioned protective film and polarizer are laminated via an intermediary layer such as an adhesive layer, an adhesive layer, and an undercoat layer (primer layer). At this time, it is ideal to use an interposer to laminate the two without an air gap. The adhesive layer is formed by the adhesive. The type of adhesive is not particularly limited, and various types can be used. The aforementioned adhesive layer is not particularly limited as long as it is optically transparent, and various forms such as water-based, solvent-based, hot-melt adhesive-based, active energy ray hardening type, etc. can be used as the adhesive. However, water-based adhesives are ideal. Agent or active energy ray hardening adhesive. Examples of water-based adhesives include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, and water-based polyesters. The water-based adhesive is usually used in the form of an adhesive composed of an aqueous solution, and usually contains 0.5 to 60% by weight of solid content. The active energy ray hardening type adhesive is an adhesive that is hardened with active energy rays such as electron beams and ultraviolet rays (radical hardening type, cation hardening type). For example, electron beam hardening type and ultraviolet hardening type can be used. As the active energy ray curable adhesive agent, for example, a light radical curable adhesive agent can be used. When the photoradical curable active energy ray curable adhesive is used as an ultraviolet curable adhesive, the adhesive contains a radical polymerizable compound and a photopolymerization initiator.

In addition, when the polarizer and the protective film are laminated, an easy-to-bond layer can be provided between the transparent protective film and the adhesive layer. The easy-adhesive layer can be formed using various resins having, for example, the following skeletons: polyester skeleton, polyether skeleton, polycarbonate skeleton, polyurethane skeleton, polysiloxane, polyamide skeleton, polyimide Skeleton, polyvinyl alcohol skeleton, etc. These polymer resins can be used individually by 1 type or in combination of 2 or more types. In addition, other additives may be added in the formation of the easy-to-bond layer. Specifically, stabilizers such as tackifiers, ultraviolet absorbers, antioxidants, and heat-resistant stabilizers can be further used.

The adhesive layer is formed of an adhesive. Various adhesives can be used for the adhesive, such as rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinylpyrrole Pyridone-based adhesives, polyacrylamide-based adhesives, cellulose-based adhesives, etc. The adhesive base polymer can be selected according to the type of the aforementioned adhesive. Among the aforementioned adhesives, it is preferable to use an acrylic adhesive in terms of excellent optical transparency, exhibiting suitable adhesive properties such as wettability, cohesiveness, and adhesiveness, and excellent weather resistance and heat resistance.

The primer layer (primer layer) is formed to improve the adhesion between the polarizer and the protective film. The material constituting the primer layer is not particularly limited as long as it exhibits a certain degree of strong adhesion to both the base film and the polyvinyl alcohol-based resin layer. For example, a thermoplastic resin excellent in transparency, thermal stability, extensibility, etc. can be used. Examples of thermoplastic resins include acrylic resins, polyolefin resins, polyester resins, polyvinyl alcohol resins, or mixtures thereof.

(Surface protection film) The first and second surface protection films are set on one side of the polarizing film (the side without an adhesive layer) in the optical film to protect the polarizing film and other optical functional films. As the base film of the first and second surface protection films, a film material having isotropy or nearly isotropy is selected from the viewpoints of inspectability and manageability. The film material may include, for example, polyester resins such as polyethylene terephthalate films, cellulose resins, acetate resins, polyether turpentine resins, polycarbonate resins, polyamide resins, etc. Transparent polymers like polyimide resins, polyolefin resins, and acrylic resins. Among them, polyester-based resins are suitable. The substrate film can also use a laminate of one or more than two types of film materials, and in addition, an extension of the aforementioned film can also be used. The thickness of the substrate film is preferably 10 μm to 150 μm or less, and more preferably 20 to 100 μm.

For the first and second surface protection films, in addition to using the aforementioned base film as a self-adhesive film, one having the aforementioned base film and adhesive layer can also be used. From the viewpoint of protecting optically functional films such as polarizing films, it is preferable to use those having an adhesive layer for the first and second surface protection films.

The adhesive layer used to laminate the first and second surface protection films, for example, can be appropriately selected and used with (meth)acrylic polymers, silicone polymers, polyesters, and polyurethanes. Ester, polyamide, polyether, fluorine-based and rubber-based polymers are used as adhesives for the base polymer. From the viewpoints of transparency, weather resistance, heat resistance, etc., an acrylic adhesive having an acrylic polymer as a base polymer is suitable. The thickness of the adhesive layer (dry film thickness) is determined according to the required adhesive force. It is usually about 1-100μm, and preferably 5-50μm.

In addition, the first and second surface protection films can be provided with a release treatment layer on the opposite side of the surface where the adhesive layer is provided, using low-adhesion materials such as silicone treatment, long-chain alkyl treatment, fluorine treatment, etc.

<Adhesive layer> For the formation of the adhesive layers 12 and 22, an appropriate adhesive can be used, and the type is not particularly limited. Examples of adhesives include rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, and polysiloxane adhesives. Vinylpyrrolidone-based adhesives, polyacrylamide-based adhesives, cellulose-based adhesives, etc.

Among these adhesives, it is suitable to use those having good optical transparency, exhibiting appropriate wettability, cohesive and adhesive properties, and excellent weather resistance and heat resistance. As those exhibiting these characteristics, it is preferable to use an acrylic adhesive.

The method of forming the adhesive layers 12 and 22, for example, can be produced by the following method: coating the aforementioned adhesive on a release film (separator, etc.) subjected to a peeling treatment, and drying to remove the polymerization solvent, etc. After the adhesive layer, transfer to the polarizer (or transparent protective film); or apply the aforementioned adhesive to the polarizer (or transparent protective film), dry and remove the polymerization solvent, etc., to form an adhesive layer on the polarizer Methods etc. In addition, when applying the adhesive, one or more solvents other than the polymerization solvent may be appropriately added.

It is advisable to use silicone release liner as the release film after release treatment. In the step of coating and drying the adhesive of the present invention on such a lining material to form an adhesive layer, a suitable and appropriate method can be used as a method for drying the adhesive according to the purpose. It is preferable to use a method of overheating and drying the above-mentioned coating film. The heating and drying temperature is preferably 40°C to 200°C, more preferably 50°C to 180°C, and particularly preferably 70°C to 170°C. By setting the heating temperature to the above range, an adhesive with excellent adhesive properties can be obtained.

Suitable drying time can be adopted. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

Various methods can be used to form the first adhesive layers 12 and 22. Specifically, for example, roller coating method, contact sizing roller coating method, gravure coating method, reverse coating method, roller brush method, spraying method, dip roller coating method, bar coating method, knife coating method, gas Knife coating method, curtain coating method, lip die coating method, extrusion coating method using a mold coater, etc.

The thickness of the first adhesive layers 12 and 22 is not particularly limited, and is, for example, about 1 to 100 μm. It is preferably 2 to 50 μm, preferably 2 to 40 μm, and more preferably 5 to 35 μm.

<Release film> The first release films 11 and 21 protect the adhesive layer until it is used for actual use. The constituent materials of the release film include, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and non-woven fabrics, meshes, foam sheets, and metals. Appropriate monolithic bodies such as foils and laminates, etc., but from the viewpoint of excellent surface smoothness, plastic films are suitably used.

The plastic film is not particularly limited as long as it is a film that can protect the aforementioned adhesive layer. Examples include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, and polymethylpentene film. Vinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate copolymer film, etc.

The thickness of the first release films 11 and 21 is usually about 5 to 200 μm, and preferably about 5 to 100 μm. If necessary, the aforementioned separating parts can be subjected to release and antifouling treatments, coating type, kneading type, etc., using polysiloxane-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agents, silica powder, etc. , Evaporation type and other antistatic treatment. In particular, by appropriately applying release treatments such as silicone treatment, long-chain alkyl treatment, fluorine treatment, etc., to the surface of the release film, the releasability of the adhesive layer can be further improved.

(Liquid crystal cell, liquid crystal display panel) The liquid crystal cell has a structure in which a liquid crystal layer is sealed between a pair of substrates (a first substrate (view side) Pa and a second substrate (rear surface) Pb) arranged opposite to each other. Any type of liquid crystal cell can be used, but in order to achieve high contrast, vertical alignment (VA) mode and in-plane switching (IPS) mode liquid crystal cells should be used. The liquid crystal display panel is a thing with a polarizing film attached to one or both sides of the liquid crystal cell, and a drive circuit is installed as needed.

(Organic EL unit, organic EL display panel) The organic EL unit has a structure in which an electroluminescent layer is sandwiched between a pair of electrodes. The organic EL unit can be any type such as a top emission type, a bottom emission type, and a dual emission type. The organic EL display panel is a thing with a polarizing film attached to one or both sides of the organic EL unit, and a drive circuit is installed as needed.

(The first panel manufacturing section of the roll-to-panel method) Fig. 2 shows an optical display panel manufacturing system of the roll-to-panel method using the roll-shaped first optical film 1. In this embodiment, the liquid crystal cell is an optical unit and the liquid crystal display panel is an optical display panel.

In the roll-shaped first optical film 1, a first release film 11, a first adhesive layer 12, a first optical function film 13, and a first surface protection film 14 are laminated in this order. As shown in FIG. 1, the roll-shaped first optical film 1 has a width a, and has a width corresponding to the long side of the liquid crystal panel (a width substantially shorter than the long side of the liquid crystal cell P).

The manufacturing system of the liquid crystal display panel of this embodiment, as shown in FIG. 2, has: a first conveying section 81 to convey the liquid crystal cell P to the first attaching section 64; and a second conveying section 82 to convey the used roll The first optical film 1 is a liquid crystal cell P with an optical film attached to the first surface P1 of the liquid crystal cell P. Each conveying section is configured to have a plurality of conveying rollers R for conveying the liquid crystal cell P by rotating around a rotating shaft, wherein the rotating shaft is parallel to the orthogonal direction of the conveying direction. Moreover, in addition to the conveying rollers, it may also be configured to have a suction tray or the like.

(Liquid crystal cell conveying step) From the accommodating section 91 accommodating the liquid crystal cell P, the liquid crystal cell P is arranged to the first conveying section 81 with the first surface P1 as the top surface, and the conveying roller R is rotated to the first attaching section 64 delivery.

(First optical film output step, first optical film cutting step) The strip-shaped first optical film 10 output from the roll-shaped first optical film 1 is cut while the first release film 11 side is sucked and fixed. The slit portion s is formed, and the cutting is performed while leaving the first release film 11 uncut, and the strip-shaped adhesive layer 12, the strip-shaped first optical functional film 13 and the strip-shaped first film are separated by the cutting portion 61. The surface protection film 14 is cut into a predetermined size (corresponding to the length of the short side of the liquid crystal cell P (substantially shorter length of the shorter side)). Examples of the cutting by the cutting portion 61 include cutting with a blade (cutting with a cutting blade) and cutting with a laser device. The arrow in Fig. 2 shows an example of the cut seam s after cutting, but for the convenience of explanation, the cut seam has been enlarged and drawn. There may be a structure in which a nip roller (not shown) is arranged on the upstream side or the downstream side of the cutting portion 61 to convey the belt-shaped first optical film 10. In addition, the nip rollers may be arranged on the upstream side and the downstream side of the cutting portion 61.

(Tension adjustment step) In the cutting process of the tape-shaped first optical film 10 and the subsequent attaching process, in order to be able to continue processing without interrupting the process over a long period of time, and to adjust the tension of the film, the first tension is provided调部62。 Adjusting section 62. The first tension adjusting unit 62 is configured to have a dancer mechanism using a spindle, for example. The not-shown nip roller may be arranged on the upstream side or the downstream side of the first tension adjusting part 62 to convey the first optical film 10. In addition, the nip rollers may be arranged on the upstream side and the downstream side of the first tension adjusting portion 62.

(Peeling step) The first optical film 10 is wound and inverted at the first peeling portion 63 to peel the first optical film 10 from the first release film 11. The first release film 11 is wound by a roller via the first winding section 65. The first winding part 65 has a roller and a rotation driving part, and the rotation driving part drives the rotation of the roller to wind the first release film 11 on the roller. In addition, a nip roller (not shown) may be arranged on the upstream side or the downstream side of the peeling part 63 to convey the first optical film 10 or the first release film 11. In addition, the nip rollers may be arranged on the upstream side and the downstream side of the peeling part 63.

(The first attaching step) The first attaching part 64 is a device for attaching the first optical film 10 from which the first release film 11 has been peeled to the liquid crystal cell P through the first adhesive layer 12 while transporting the liquid crystal cell P On the first side P1. The first attaching portion 64 is composed of a pair of a first roller member 64a and a second roller member 64b. Either one of them may be a driving roller and the other may be a driven roller, or both of the rollers may be driving rollers. The paired first roller member 64a and second roller member 64b are fed downstream while sandwiching the first optical film 10 and the liquid crystal cell P, so that the first optical film 10 is pasted against the first surface P1 of the liquid crystal cell P Attached. The liquid crystal cell P on which the single sheet-shaped first optical film 10 has been attached to the first surface P1 of the liquid crystal cell P is conveyed downstream by the second conveying unit 82.

(Second panel manufacturing section of the sheet-to-panel method) Fig. 3 shows an optical display panel manufacturing system of the sheet-to-panel method using the single-piece-shaped first optical film 2. In this embodiment, the liquid crystal cell is an optical unit and the liquid crystal display panel is an optical display panel.

The monolithic first optical film 2 has a first release film 21, a first adhesive layer 22, a first optical function film 23, a first surface protection film 24, and a second surface protection film laminated in this order. As shown in FIG. 1, the monolithic first optical film 2 is longitudinally a and laterally b, and has a width corresponding to the long side of the liquid crystal panel (a width substantially shorter than the long side of the liquid crystal cell P).

The manufacturing system of the liquid crystal display panel in this embodiment has, as shown in FIG. 3, a third conveying section 181 that conveys the liquid crystal cell P to the single-piece bonding device 164 (equivalent to the second bonding section); and The fourth conveying unit 182 conveys the liquid crystal cell P after the optical film is attached to the first surface P1 of the liquid crystal cell P using the single-sheet first optical film 2. Each conveying section is configured to have a plurality of conveying rollers R for conveying the liquid crystal cell P by rotating around a rotating shaft, wherein the rotating shaft is parallel to the orthogonal direction of the conveying direction. Moreover, in addition to the conveying rollers, it may also be configured to have a suction tray or the like.

(Liquid crystal cell conveying step) From the accommodating section 191 where the liquid crystal cell P is housed, the liquid crystal cell P is arranged to the third conveying section 181 so that the first surface P1 is the top surface, and the rotation of the conveying roller R is used to move to the sheet bonding device 164 delivery.

The suction part 164a of the single-piece bonding apparatus 164 sucks the single-piece-shaped first optical film 2 from the container 100 containing the single-piece-shaped first optical film 2 and supplies it to the bonding position. The first release film 21 is peeled from the single sheet-shaped first optical film 2 by a peeling means. The suction surface of the suction portion 164a has an arc shape in cross section. The peeling means may be, for example, by using an adhesive tape, sticking the adhesive tape on the surface of the first release film 21, and moving the adhesive tape by a moving mechanism to peel the first release film 21.

The single-piece bonding device 164 has a fixed surface 164b, and the fixed surface 164b sucks and fixes the first surface P1 side of the liquid crystal cell P. In a state where the first release film 21 has been peeled off and the first adhesive layer 22 is exposed, the single-piece second optical film 2 is attached to the first surface P1 of the liquid crystal cell P such that the suction portion 164a is rotated.

(Second surface protection film peeling step) After the single sheet-like first optical film 2 is attached, the second surface protection film 25 is peeled off. The peeling process can be implemented manually or by a peeling device.

In the above-mentioned first panel manufacturing section, the optical film is attached to one surface (first surface P1) of the liquid crystal cell by a roll-to-panel method, but it is not limited to this. The optical film can also be attached to the other side (the second side P2) of the liquid crystal cell in a roll-to-panel method or a sheet-to-panel method.

In the second panel manufacturing section described above, the optical film is attached to one surface (first surface P1) of the liquid crystal cell by a sheet-to-panel method, but it is not limited to this. The optical film can also be attached to the other side (the second side P2) of the liquid crystal cell in a roll-to-panel method or a sheet-to-panel method.

In the above-mentioned first and second panel manufacturing sections, optical inspection can be performed after the optical film is attached to either side or both sides. According to the results of the optical inspection (for example, in the case of defective products), the optical film can be removed from the liquid crystal cell (optical unit), and the optical unit can be attached again in the second panel manufacturing department (sheet-to-panel method) to manufacture the liquid crystal display Panel (optical display panel).

(Variation) This embodiment is to describe the continuous manufacturing method of using the optical film group of the roll optical film and the monolithic optical film in the liquid crystal display panel, but it is not limited to this, and can also be used in the continuous manufacturing of the organic EL display panel. Production method.

In the embodiment, the above-mentioned optical film is used as a roll optical film, but the structure of the roll optical film is not limited to this. For example, in addition to the release film, a strip-shaped optical film having a plurality of slit lines formed in the width direction (optical film including slits) can be used.

In the embodiment, the tape-shaped optical film is cut (half-cut) in the width direction at predetermined intervals. However, from the viewpoint of improving the yield, the tape-shaped optical film is cut across the width in a way that avoids the defects of the tape-shaped optical film. Directional cutting (skip cut) is also possible, and the optical film containing defective parts may be cut in a smaller size (preferably as small as possible) than the predetermined interval (the size of the optical unit).

The embodiment is described by taking an oblate rectangular liquid crystal cell and a liquid crystal display panel as an example, but the shape of the liquid crystal cell and the liquid crystal display panel is not particularly limited as long as it has one set of opposite sides and another set of opposite sides.

1‧‧‧Roll Optical Film 10‧‧‧Strip optical film 11‧‧‧Release film 12‧‧‧Adhesive layer 13‧‧‧Optical function film 14‧‧‧The first surface protective film 2‧‧‧Single sheet optical film 21‧‧‧Release film 22‧‧‧Adhesive layer 23‧‧‧Optical function film 24‧‧‧The first surface protective film 25‧‧‧Second surface protective film a‧‧‧Width, vertical b‧‧‧Predetermined interval, horizontal s‧‧‧Cutting part C‧‧‧cutting method 61‧‧‧Cut off 62‧‧‧The first tension adjustment part 63‧‧‧The first peeling part 64‧‧‧Part 1 Attachment 64a‧‧‧The first roller 64b‧‧‧The second roller 65‧‧‧Volume 1 81‧‧‧The first conveying department 82‧‧‧The second conveying department 91‧‧‧Receiving Department 100‧‧‧Container 164‧‧‧Single piece bonding device 164a‧‧‧Adsorption part 164b‧‧‧Fixed surface 181‧‧‧Conveying Department 3 182‧‧‧4th Conveying Department 191‧‧‧Receiving Department R‧‧‧Conveying roller P1‧‧‧The first side of LCD unit P P2‧‧‧Second side of LCD unit P P‧‧‧LCD unit Y‧‧‧Conveying direction

Fig. 1 is a schematic diagram showing the optical film set of the first embodiment. Figure 2 is a schematic diagram of a roll-to-panel manufacturing system. Figure 3 is a schematic diagram of a sheet-to-panel manufacturing system.

1‧‧‧Roll Optical Film

10‧‧‧Strip optical film

11‧‧‧Release film

12‧‧‧Adhesive layer

13‧‧‧Optical function film

14‧‧‧The first surface protective film

2‧‧‧Single sheet optical film

21‧‧‧Release film

22‧‧‧Adhesive layer

23‧‧‧Optical function film

24‧‧‧The first surface protective film

25‧‧‧Second surface protective film

a‧‧‧Width, vertical

b‧‧‧Predetermined interval, horizontal

s‧‧‧Cutting part

C‧‧‧cutting method

Claims (8)

A method for manufacturing an optical display panel includes the following steps: a first panel manufacturing step, including a first attaching step, which uses a roll-shaped optical film wound by a ribbon-shaped optical film on at least any side of the optical unit Attaching the optical film to form an optical display panel; and a second panel manufacturing step, including a second attaching step, which is to attach a monolithic optical film to at least any side of the optical unit to form an optical display panel; wherein, the aforementioned The first attaching step is: peeling off the release film from the release film, the adhesive layer, the optical function film, and the first surface protection film, which have been output from the roll optical film and have a structure in which a release film, an adhesive layer, an optical function film, and a first surface protection film are sequentially laminated. The optical film is attached to at least any one surface of the optical unit through the exposed adhesive layer; the second attaching step is: from the structure, the release film and the adhesive are sequentially laminated Layer, the optical function film, the first surface protection film, and the second surface protection film of the single sheet optical film. The release film is peeled off, and the single sheet optical film is attached through the exposed adhesive layer On at least any one surface of the optical unit; and, the second panel manufacturing step includes: a second surface protection film peeling step, which is to remove the single-piece optical film from the single-piece optical film in a state that has been attached to the optical unit Surface protection 2 The protective film peels off; the first surface protective film has an adhesive layer or the first surface protective film is a self-adhesive film; the second surface protective film has an adhesive layer or the second surface protective film is a self-adhesive film; The first surface protective film and the second surface protective film have the same structure; suppose the interlayer peeling force between the release film and the adhesive layer is the interlayer peeling force A, and the interlayer peeling force between the adhesive layer and the optical function film is When the interlayer peeling force B, the interlayer peeling force between the optical functional film and the first surface protective film is the interlayer peeling force C, and the interlayer peeling force between the first surface protective film and the second surface protective film is the interlayer peeling force D, The size relationship of the peeling force between the layers in the aforementioned single-piece optical film is A<D<C<B. The method of manufacturing an optical display panel of claim 1, wherein the first attaching step includes the following step: a cutting step, which is to retain the release film on the tape-shaped optical film output from the aforementioned roll-shaped optical film Next, cutting in a direction orthogonal to the longitudinal direction of the optical film; and a peeling step in which the release film is peeled from the optical film. The method for manufacturing an optical display panel according to claim 1, wherein the strip-shaped optical film is formed with slits at predetermined intervals in a portion other than the release film, and The first attaching step includes a peeling step of peeling the release film from the optical film output from the roll optical film by folding back inward. The method for manufacturing an optical display panel according to claim 1, wherein the optically functional film of the monolithic optical film is a polarizing film having a thickness of 60 μm or less, and the polarizing film has a polarizing member having a thickness of 10 μm or less. A manufacturing system for an optical display panel, comprising: a first panel manufacturing section, including a first attaching section, which is a roll-shaped optical film wound by using a ribbon-shaped optical film, and attaching the optical film to at least any one surface of the optical unit An optical film to form an optical display panel; and a second panel manufacturing section, including a second attaching section, which is formed by attaching a monolithic optical film to at least any one side of the optical unit to form an optical display panel; wherein, the first attaching Attachment system: peel off the release film from the tape-shaped optical film that has been output from the roll-shaped optical film and has a structure in which a release film, an adhesive layer, an optical function film, and a first surface protection film are sequentially laminated, and Attach the optical film to at least any one surface of the optical unit through the exposed adhesive layer; the second attaching part is structured in that the release film, the adhesive layer, and the The single-piece optical film of the optical function film, the first surface protection film, and the second surface protection film peels off the release film and passes through the exposed film. From the adhesive layer, the single-piece optical film is attached to at least any one surface of the optical unit; and the second panel manufacturing section has: a second surface protection film peeling section, which is attached from The single-piece optical film in the state of the optical unit peels off the second surface protection film; the first surface protection film has an adhesive layer or the first surface protection film is a self-adhesive film; the second surface protection The film has an adhesive layer or the second surface protection film is a self-adhesive film; the first surface protection film and the second surface protection film have the same structure; the interlayer peeling force between the release film and the adhesive layer is set as the interlayer Peeling force A, the peeling force between the adhesive layer and the optical function film is the interlayer peeling force B, the peeling force between the optical function film and the first surface protective film is the interlayer peeling force C, the first surface protective film When the interlayer peeling force with the second surface protection film is the interlayer peeling force D, the magnitude relationship of the peeling force between the layers in the single-sheet optical film is A<D<C<B. According to claim 5, the optical display panel manufacturing system, wherein the first attaching part has: a cutting part, which is the strip-shaped optical film output from the aforementioned roll-shaped optical film, while keeping the release film under the The optical film is cut in a direction orthogonal to the longitudinal direction of the optical film; and The peeling part peels the said release film from the said optical film. The optical display panel manufacturing system of claim 5, wherein the strip-shaped optical film is formed with slits at predetermined intervals in parts other than the release film, and the first attaching part has a peeling part, which is obtained by The release film is peeled from the optical film output from the roll-shaped optical film by folding back inward. The optical display panel manufacturing system of claim 5, wherein the optically functional film of the monolithic optical film is a polarizing film having a thickness of 60 μm or less, and the polarizing film has a polarizing member having a thickness of 10 μm or less.

Images