JP6732580B2 - Optical display panel manufacturing method and optical display panel manufacturing system - Google Patents

Description

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

An optical film in which a release film, a pressure-sensitive adhesive layer, an optical functional film (typically a polarizing film) and a surface protective film are laminated in this order is configured in a roll shape. An optical film obtained by cutting (half-cutting) the pressure-sensitive adhesive layer, the optical function film and the surface protection film in the width direction while leaving the release film, the optical film fed out from this roll-shaped optical film, and cutting. There is a method (hereinafter, also referred to as “roll-to-panel method”) in which the release film is peeled from the optical film and the optical film is attached to the optical cell via the exposed adhesive layer (for example, Patent Documents 1 and 2). reference).

On the other hand, as an optical film laminating method different from the roll-to-panel method, an optical film that has been put into a single-wafer state in advance is attached to an optical cell through an adhesive layer exposed by peeling the release film. There is a matching method (hereinafter, also referred to as “sheet-to-panel method”) (for example, see Patent Document 3).

JP, 2011-123208, A JP, 2015-049115, A JP, 2006-039238, A

At present, optical display panel manufacturing plants currently have a large number of sheet-to-panel manufacturing facilities, and few roll-to-panel manufacturing facilities.

In recent years, as optical display panels have become thinner, polarizing films and other optical functional films thinner than conventional ones (for example, polarizing films having a thickness of 60 μm or less) are being developed. Such a thin optical functional film has a low waist (elastic modulus), and is likely to be twisted or curled. Therefore, there is a concern that the current sheet-to-panel manufacturing equipment cannot handle it.

At the manufacturing site of optical display panels such as liquid crystal display panels, there is a new case where not only the roll-to-panel method but also the sheet-to-panel method is used to manufacture an optical display panel with the same configuration. It has occurred. For example, Patent Document 2 discloses that an optical display panel is continuously manufactured by using a roll-to-panel method, and a rework process is performed on the optical display panel determined to be defective. When a large number of defective products do not occur, it is conceivable to use a sheet-to-panel method when bonding a new optical functional film to the optical cell in such a rework process. In addition, for example, when a large number of optical display panels with the same configuration must be produced in a short period of time, the roll-to-panel method cannot cover all the supply amount, and the sheet-to-panel method is used in combination. Can also be considered.

However, as described above, as the optical film becomes thinner, twisting and curling are more likely to occur. Therefore, in the sheet-to-panel method, sheet-shaped optical film is conveyed, release film is peeled, and optical functional film is used. Since it becomes difficult to handle such as the bonding process to the liquid crystal cell, the yield may be significantly reduced.

INDUSTRIAL APPLICABILITY The present invention is capable of suitably manufacturing an optical display panel having the same configuration even when a roll-to-panel system and a sheet-to-panel system are used together when a thin optical functional film is attached to an optical cell. It is an object to provide a method for manufacturing a display panel.

The present invention uses a roll-shaped optical film formed by winding a band-shaped optical film, and at least one surface of an optical cell is adhered to the optical film to form an optical display panel. A first panel manufacturing process including
A method for manufacturing an optical display panel, comprising: a second panel manufacturing step including a second bonding step in which a sheet-shaped optical film is bonded to at least one surface of the optical cell to form an optical display panel,
In the first attaching step,
The release film is peeled off from the strip-shaped optical film that is fed from the roll-shaped optical film and has a configuration in which a release film, a pressure-sensitive adhesive layer, an optical functional film, and a first surface protection film are laminated in this order. Via the adhesive layer exposed by the above, the optical film is attached to the at least one surface of the optical cell,
In the second attaching step,
The release film is peeled from the sheet-shaped optical film having a configuration in which the release film, the pressure-sensitive adhesive layer, the optical functional film, the first surface protection film, and the second surface protection film are laminated in this order. Via the exposed adhesive layer, the sheet-shaped optical film is attached to the at least one surface of the optical cell,
In the second panel manufacturing process,
The method includes a second surface protection film peeling step of peeling the second surface protection film from the sheet-shaped optical film attached to the optical cell.

In the above invention, the first attaching step is a cutting step of cutting the strip-shaped optical film fed from the roll-shaped optical film, leaving the release film in a direction orthogonal to the longitudinal direction of the optical film. When,
A peeling step of peeling the release film from the optical film may be included.

In the above invention, the strip-shaped optical film, notches are formed at predetermined intervals except the release film,
The first attaching step may include a peeling step of peeling the release film by folding the release film inward from the optical film fed from the roll-shaped optical film.

Further, another invention uses a roll-shaped optical film formed by winding a strip-shaped optical film, and forms an optical display panel by attaching the optical film to at least one surface of an optical cell. 1st panel manufacturing department including 1 pasting department,
A system for manufacturing an optical display panel, comprising: a second panel manufacturing unit including a second bonding unit that bonds a sheet-shaped optical film to form an optical display panel on at least one surface of an optical cell,
The first pasting section,
The release film is peeled off from the strip-shaped optical film that is fed from the roll-shaped optical film and has a configuration in which a release film, a pressure-sensitive adhesive layer, an optical functional film, and a first surface protection film are laminated in this order. Via the adhesive layer exposed by the above, the optical film is attached to the at least one surface of the optical cell,
The second pasting section,
The release film is peeled from the sheet-shaped optical film having a configuration in which the release film, the pressure-sensitive adhesive layer, the optical functional film, the first surface protection film, and the second surface protection film are laminated in this order. Via the exposed adhesive layer, the sheet-shaped optical film is attached to the at least one surface of the optical cell,
The second panel manufacturing department
You may have the 2nd surface protection film peeling part which peels the said 2nd surface protection film from the said sheet-like optical film in the state affixed to the said optical cell.

In the above-mentioned invention, the 1st pasting part is a cutting part which cuts the strip-shaped optical film extended from the roll-shaped optical film, leaving the release film in a direction orthogonal to the longitudinal direction of the optical film. When,
You may have the peeling part which peels the said release film from the said optical film.

In the above invention, the strip-shaped optical film, notches are formed at predetermined intervals except the release film,
The first sticking portion may have a peeling portion that peels by peeling the release film inward from the optical film fed from the roll-shaped optical film.

In the above invention, when a polarizing film is used as the optical functional film, the first optical functional film, or the second optical functional film, or when a polarizing film is included as one member of the constitution, absorption of a belt-shaped polarizing film. The axial direction may be parallel to the longitudinal direction of the strip-shaped polarizing film, may be orthogonal to the longitudinal direction, or may be oblique (for example, a direction forming an angle of 45° with the longitudinal direction). Further, the absorption axis direction of the rectangular sheet-shaped polarizing film may be parallel to the longitudinal direction, orthogonal to the longitudinal direction, or oblique (for example, a direction forming an angle of 45° with the longitudinal direction). May be. The absorption axis direction of the square sheet-shaped polarizing film may be parallel to any one side or may be oblique (for example, a direction forming an angle of 45° with the side).

In the present invention, in the roll-shaped optical film, the pressure-sensitive adhesive layer, the optical functional film and the surface protective film are opposed to the optical cell in the direction (width direction) orthogonal to the longitudinal direction of the optical film while leaving the release film. Notches may be formed at intervals corresponding to another set of sides. According to this configuration, there is no need to cut (half cut) the optical film in the roll-to-panel method.

In the above invention, the optical cell may be a VA mode or IPS mode liquid crystal cell or an organic EL cell.

The shape of the optical cell may be square or rectangular, and is not particularly limited, as long as it has a pair of opposite sides and another pair of opposite sides. It should be noted that, usually, a pair of opposing sides of the optical cell and another pair of opposing sides are orthogonal to each other.

The "roll-to-panel method" is a method in which a release film is peeled from an optical film fed from a roll-shaped optical film, and the optical film is attached to an optical cell via an exposed adhesive layer. Here, before the release film is peeled off, it is sufficient that cut lines are formed in the optical film at predetermined intervals in the width direction while leaving the release film. A cut line may be formed in the optical film before being drawn out, or a cut line may be formed in the optical film before the release film is peeled off after being drawn out.

The "sheet-to-panel method" is a method in which a release film is peeled from an optical film that has been previously put into a single-wafer state, and the optical film is attached to an optical cell via an exposed adhesive layer.

The roll-shaped optical film is an optical display in which a pressure-sensitive adhesive layer, an optical functional film and a first surface protective film are laminated in this order on at least one surface of an optical cell by using a roll-to-panel method. Used in manufacturing panels. Further, since the sheet-like optical film provided with the second surface protection film has improved handleability, the sheet-to-panel method is used while suppressing the occurrence of twisting, curling, and the like. , An optical display panel having a structure in which an adhesive layer, an optical functional film, and a first surface protective film are laminated in this order on at least one surface of an optical cell. Then, the second surface protection film is removed (for example, peeled) from the sheet-shaped optical film attached to the optical display panel. As a result, an optical display panel having the same laminated structure as the optical display panel manufactured by the roll-to-panel method can also be manufactured by the sheet-to-panel method.

Schematic diagram showing the optical film set of Embodiment 1. Schematic diagram of roll-to-panel manufacturing system Schematic of sheet-to-panel manufacturing system

<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 set. A side view, a plane, and a partial cross-sectional enlarged view of the roll-shaped first optical film 1 are shown in the upper part of FIG. A side view, a plane, and a partial cross-sectional enlarged view of the sheet-shaped first optical film 2 are shown in the lower part of FIG. The roll-shaped first optical film 1 includes a first release film 11, a first pressure-sensitive adhesive layer 12, a first optical functional film 13, and a first surface protection film 14, which 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 such a case, the strip-shaped first optical film 10 having the width a, which is unrolled from the roll-shaped first optical film 1, is cut by the cutting means C with the release film 11 left at a predetermined interval b. Reference numeral s is a notch formed in the first optical film 10 by the above cutting.

The sheet-shaped first optical film 2 includes a first release film 21, a first pressure-sensitive adhesive layer 22, a first optical function film 23, a first surface protection film 24, and a second surface protection film 25 laminated in this order. Has been done. The size of the sheet-shaped first optical film 2 is length a and width b. The sheet-shaped first optical film 2 is used for manufacturing 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 configuration. The first adhesive layer 12 and the first adhesive layer 22 have the same configuration. The first optical function film 13 and the first optical function film 23 have the same configuration. The first surface protection film 14, the first surface protection film 24, and the second surface protection film 25 have the same structure. The “same configuration” does not have to be the same in material, thickness, etc., but may be substantially the same (for example, in terms of manufacturing quality).

In the present embodiment, the first surface protection film 14 (or 24) has a first base material film and a first pressure-sensitive adhesive layer, and the first optical function film 13 (or 23) via the first pressure-sensitive adhesive layer. ) Are stacked. In addition, as another embodiment, the first surface protection film 14 (or 24) may be a self-adhesive film.

In the present embodiment, the second surface protection film 25 has a second base film and a second pressure-sensitive adhesive layer, and is laminated on the first surface protection film 24 via the second pressure-sensitive adhesive layer. In addition, as another embodiment, the second surface protection film 25 may be a self-adhesive film.

(Relationship between interphase peeling force)
In addition, the peeling force between the layers of the first surface protection film 24 and the first optical function film 23 is larger than the peeling force between the layers of the second surface protection film 25 and the first surface protection film 24. According to this, the 2nd surface protection film 25 can be peeled off more smoothly. For measuring the peeling force, for example, a tensile tester can be used. The peeling condition is a 180° peeling of 0.3 m/min. The peeling force is controlled by the composition and thickness of the adhesive.

The magnitude relationship of the peeling force between the layers in the sheet-shaped first optical film 2 is as follows.
Interlayer peeling force A between the first release film 21 and the first pressure-sensitive adhesive layer 22,
Interlayer peeling force B between the first adhesive layer 22 and the first optical functional film 23,
Delamination force C between the first optical function film 23 and the first surface protection film 24,
When the interlayer peeling force D between the first surface protection film 24 and the second surface protection film 25 is set,
A<B, A<C, A<D.
Preferably, A<D<C≦B or A<D<B≦C.
More preferably, A<D<C<B.
According to the relationship between the interphase peeling forces, it is possible to prevent the second surface protection film from peeling off when the first release film is peeled off.

<Optical function film>
The first optical function films 13 and 23 are not particularly limited as long as they are films having an optical function, and examples thereof include a polarizing film, a retardation film, a brightness enhancement film, a diffusion film, and the like, but typically a polarizing film. ..

(Polarizing film)
In the present embodiment, from the viewpoint of thinning, it is preferable to use a polarizing film having a thickness (total thickness) of 60 μm or less, more preferably 55 μm or less, and further preferably 50 μm or less. As the polarizing film, for example, (1) a configuration in which protective films (may be referred to as “polarizer protective film”) are laminated on both sides of the polarizer (may be referred to as “both protective polarizing films”). (2) A configuration in which a protective film is laminated only on one side of the polarizer (sometimes referred to as a “single protective polarizing film”) and the like.

(Polarizer)
A polarizer using a polyvinyl alcohol resin is used as the polarizer. Examples of the polarizer include hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene/vinyl acetate copolymer partially saponified films, and dichroic dyes such as iodine and dichroic dyes. Examples thereof include polyene-based oriented films such as substances adsorbed and uniaxially stretched, polyvinyl alcohol dehydration products, polyvinyl chloride dehydrochlorination products, and the like. Among these, a polarizer made of a polyvinyl alcohol film and a dichroic substance such as iodine is preferable.

A polarizer obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching can be produced, for example, by dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine and stretching it to 3 to 7 times its original length. If necessary, boric acid, zinc sulfate, zinc chloride, etc. may be contained, or the solution may be immersed in an aqueous solution of potassium iodide or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed with water before dyeing. By washing the polyvinyl alcohol-based film with water, it is possible to wash the stains and anti-blocking agent on the surface of the polyvinyl alcohol-based film, and by swelling the polyvinyl alcohol-based film, the effect of preventing unevenness such as uneven dyeing is also obtained. is there. Stretching may be performed after dyeing with iodine, stretching while dyeing, or stretching and then dyeing with iodine. Stretching can be performed in an aqueous solution of boric acid or potassium iodide or in a water bath.

The thickness of the polarizer is preferably 10 μm or less, more preferably 8 μm or less, further preferably 7 μm or less, further preferably 6 μm or less from the viewpoint of thinning. 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 little thickness unevenness and excellent visibility, and since it has little dimensional change, it has excellent durability against thermal shock. On the other hand, a polarizing film including a polarizer having a thickness of 10 μm or less has a significantly low stiffness (elastic modulus), and therefore, in the sheet-to-panel method, twisting, curling, and the like are likely to occur. Therefore, the present invention is particularly suitable for the polarizing film.

As a thin polarizer, typically,
Patent No. 4751486 specification,
Patent No. 4751481,
Japanese Patent No. 4815544,
Japanese Patent No. 5048120,
International Publication 2014/0775599 pamphlet,
International Publication 2014/077636 pamphlet,
And the thin polarizers obtained from the production methods described therein.

The polarizer has optical characteristics represented by a single transmittance T and a polarization degree P as expressed by the following formula P>−(10 ^{0.929T−42.4} −1)×100 (where T<42.3), Or
P≧99.9 (however, T≧42.3)
It is preferable that it is configured so as to satisfy the above condition. The polarizer configured so as to satisfy the above conditions has the performance uniquely required as a display for a liquid crystal television using a large display element. Specifically, the contrast ratio is 1000:1 or more and the maximum brightness is 500 cd/m ² or more. As another application, for example, it is attached to the visible side of the organic EL cell.

As the thin polarizer, among manufacturing methods including a step of stretching in the state of a laminated body and a step of dyeing, in that it can be stretched at a high magnification and the polarization performance can be improved, Japanese Patent No. 4751486 Specification, Patent Those obtained by a production method including a step of stretching in a boric acid aqueous solution as described in Japanese Patent No. 47514881 and Japanese Patent No. 4815544 are preferable, and particularly described in Japanese Patent Nos. 4751481 and 4815544. What is obtained by a production method including a step of auxiliary stretching in the air before stretching in a boric acid aqueous solution is preferable. These thin polarizers can be obtained by a production method including a step of stretching a polyvinyl alcohol-based resin (hereinafter, also referred to as PVA-based resin) layer and a stretching resin base material in a laminate state and a dyeing step. According to this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without trouble such as breakage due to stretching because it is supported by the stretching resin base material.

(Protective film (polarizer protective film))
As a material forming the protective film, a material having excellent transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. is preferable. For example, polyester-based polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose-based polymers such as diacetyl cellulose and triacetyl cellulose, acrylic-based polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin). Examples thereof include a polymer and a polycarbonate polymer. Further, polyethylene, polypropylene, polyolefins having a cyclo or norbornene structure, polyolefin polymers such as ethylene/propylene copolymers, vinyl chloride polymers, amide polymers such as nylon and aromatic polyamide, imide polymers, sulfone polymers. , Polyethersulfone-based polymer, polyetheretherketone-based polymer, polyphenylene sulfide-based polymer, vinyl alcohol-based polymer, vinylidene chloride-based polymer, vinyl butyral-based polymer, arylate-based polymer, polyoxymethylene-based polymer, epoxy-based polymer, or the above Blends of polymers and the like are also mentioned as examples of the polymer forming the protective film.

The protective film may contain one or more kinds of any appropriate additive. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, an anti-coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment and a coloring agent. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, further preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. .. When the content of the thermoplastic resin in the transparent protective film is 50% by weight or less, the high transparency and other properties inherent in the thermoplastic resin may not be sufficiently exhibited.

As the protective film, a retardation film, a brightness enhancement film, a diffusion film or the like can also be used.

A functional layer such as a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer or an antiglare layer may be provided on the surface of the protective film to which the polarizer is not adhered. The functional layers such as the hard coat layer, the antireflection layer, the antisticking layer, the diffusion layer and the antiglare layer can be provided on the transparent protective film itself, or separately, separately from the transparent protective film. You can also

(Intervening layer)
The protective film and the polarizer are laminated via intervening layers such as an adhesive layer, a pressure-sensitive adhesive layer, and an undercoat layer (primer layer). At this time, it is desirable that both layers are laminated without an air gap by an intervening layer.
The adhesive layer is formed of an adhesive. The type of adhesive is not particularly limited, and various types can be used. The adhesive layer is not particularly limited as long as it is optically transparent, and as the adhesive, various forms such as water-based, solvent-based, hot melt-based and active energy ray-curable adhesives are used. Alternatively, an active energy ray-curable adhesive is suitable.
Examples of the water-based adhesive 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 as an adhesive composed of an aqueous solution, and usually contains 0.5 to 60% by weight of solid content.
The active energy ray-curable adhesive is an adhesive that is cured by active energy rays such as electron beams and ultraviolet rays (radical curable type, cation curable type), and is, for example, an electron beam curable type or an ultraviolet ray curable type. Can be used. As the active energy ray curable adhesive, for example, a photo radical curable adhesive 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.

When laminating the polarizer and the protective film, an easily adhesive layer can be provided between the transparent protective film and the adhesive layer. The easy-adhesion layer can be formed of various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone-based, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, or the like. These polymer resins may be used alone or in combination of two or more. Further, other additives may be added to form the easily adhesive layer. Specifically, a tackifier, a UV absorber, an antioxidant, a stabilizer such as a heat stabilizer and the like may be used.

The adhesive layer is formed from an adhesive. As the pressure-sensitive adhesive, various pressure-sensitive adhesives can be used, for example, rubber-based pressure-sensitive adhesives, acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, urethane-based pressure-sensitive adhesives, vinyl alkyl ether-based pressure-sensitive adhesives, polyvinylpyrrolidone-based pressure-sensitive adhesives, poly-based pressure-sensitive adhesives. Examples thereof include acrylamide adhesives and cellulose adhesives. An adhesive base polymer is selected according to the type of the adhesive. Among the pressure-sensitive adhesives, an acrylic pressure-sensitive adhesive is preferably used because it is excellent in optical transparency, exhibits appropriate wettability, cohesiveness, and adhesive property of adhesiveness and is excellent in weather resistance and heat resistance. It

The undercoat layer (primer layer) is formed in order to improve the adhesion between the polarizer and the protective film. The material forming the primer layer is not particularly limited as long as it is a material that 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, stretchability, etc. is used. Examples of the thermoplastic resin include acrylic resins, polyolefin resins, polyester resins, polyvinyl alcohol resins, and mixtures thereof.

(Surface protection film)
The first and second surface protective films are provided on one surface (the surface on which the pressure-sensitive adhesive layer is not laminated) of the polarizing film in the optical film, and protect the optical functional film such as the polarizing film.
As the base film of the first and second surface protection films, a film material having isotropic property or close to isotropic property is selected from the viewpoints of inspection property and manageability. Examples of the film material include polyester resin such as polyethylene terephthalate film, cellulose resin, acetate resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, acrylic resin. Examples include transparent polymers such as resins. Of these, polyester resins are preferred. The base film may be used as a laminate of one or two or more film materials, or a stretched product of the film may be used. The thickness of the substrate film is preferably 10 μm to 150 μm or less, and more preferably 20 to 100 μm.

As the first and second surface protection films, the above-mentioned base film can be used as a self-adhesive film, and also those having the above-mentioned base film and an adhesive layer can be used. From the viewpoint of protecting the optical functional film such as the polarizing film, it is preferable to use the first and second surface protective films having a pressure-sensitive adhesive layer.

Examples of the pressure-sensitive adhesive layer used for laminating the first and second surface protective films include (meth)acrylic polymers, silicone polymers, polyesters, polyurethanes, polyamides, polyethers, fluorine-based and rubber-based polymers. The pressure-sensitive adhesive used as the base polymer can be appropriately selected and used. From the viewpoint of transparency, weather resistance, heat resistance, etc., an acrylic pressure-sensitive adhesive containing an acrylic polymer as a base polymer is preferable. The thickness of the adhesive layer (dry film thickness) is determined according to the required adhesive force. It is usually about 1 to 100 μm, preferably 5 to 50 μm.

In the first and second surface protection films, a release treatment layer may be provided on the surface opposite to the surface provided with the pressure-sensitive adhesive layer, using a low-adhesion material such as silicone treatment, long-chain alkyl treatment, or fluorine treatment. it can.

<Adhesive layer>
An appropriate pressure-sensitive adhesive can be used to form the pressure-sensitive adhesive layers 12 and 22, and the type thereof is not particularly limited. As the adhesive, a rubber adhesive, an acrylic adhesive, a silicone adhesive, a urethane adhesive, a vinyl alkyl ether adhesive, a polyvinyl alcohol adhesive, a polyvinylpyrrolidone adhesive, a polyacrylamide adhesive, Cellulose adhesives and the like can be mentioned.

Among these pressure-sensitive adhesives, those having excellent optical transparency, exhibiting appropriate wettability, cohesiveness and adhesiveness, and excellent weather resistance and heat resistance are preferably used. An acrylic pressure-sensitive adhesive is preferably used to exhibit such characteristics.

As a method of forming the pressure-sensitive adhesive layers 12 and 22, for example, a release film obtained by subjecting the pressure-sensitive adhesive to a release treatment (a separator or the like is applied, and a polymerization solvent or the like is dried and removed to form a pressure-sensitive adhesive layer, and then a polarizer is used. (Or a transparent protective film), or a method of applying the pressure-sensitive adhesive to the polarizer (or the transparent protective film) and drying and removing a polymerization solvent to form a pressure-sensitive adhesive layer on the polarizer. When applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be appropriately added.

A silicone release liner is preferably used as the release film subjected to the release treatment. In the step of forming the pressure-sensitive adhesive layer by coating the pressure-sensitive adhesive of the present invention on such a liner and drying the pressure-sensitive adhesive, a suitable method can be adopted depending on the purpose. Preferably, a method of overheating and drying the above coating film is used. 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 in the above range, a pressure-sensitive adhesive having excellent pressure-sensitive adhesive properties can be obtained.

As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 2
0 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

Various methods are used as a method of forming the first pressure-sensitive adhesive layers 12 and 22. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples of the method include an extrusion coating method.

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

<Release film>
The first release films 11 and 21 protect the pressure-sensitive adhesive layer until practical use. Examples of the constituent material of the release film include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and non-woven fabric, nets, foam sheets, metal foils, and laminates thereof. Examples of suitable thin leaves include plastic films, and plastic films are preferably used because of their excellent surface smoothness.

The plastic film is not particularly limited as long as it is a film capable of protecting the pressure-sensitive adhesive layer, and examples thereof include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film and vinyl chloride. Examples thereof include polymer films, polyethylene terephthalate films, polybutylene terephthalate films, polyurethane films, ethylene-vinyl acetate copolymer films and the like.

The thickness of the first release films 11 and 21 is usually 5 to 200 μm, preferably about 5 to 100 μm. In the separator, if necessary, a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, release and antifouling treatment with silica powder or the like, coating type, kneading type, vapor deposition type It is also possible to perform antistatic treatment such as. In particular, the release property from the pressure-sensitive adhesive layer can be further enhanced by appropriately subjecting the surface of the release film to release treatment such as silicone treatment, long-chain alkyl treatment, and fluorine treatment.

(Liquid crystal cell, liquid crystal display panel)
The liquid crystal cell has a configuration in which a liquid crystal layer is sealed between a pair of substrates (a first substrate (viewing side surface) Pa and a second substrate (back surface) Pb) that are opposed to each other. Although any type of liquid crystal cell can be used, it is preferable to use a vertical alignment (VA) mode or in-plane switching (IPS) mode liquid crystal cell in order to realize high contrast. The liquid crystal display panel is one in which a polarizing film is attached to one side or both sides of a liquid crystal cell, and a drive circuit is incorporated as necessary.

(Organic EL cell, organic EL display panel)
The organic EL cell has a structure in which an electroluminescent layer is sandwiched between a pair of electrodes. The organic EL cell may be of any type such as a top emission type, a bottom emission type, a double emission type, or the like. The organic EL display panel is one in which a polarizing film is attached to one side or both sides of an organic EL cell, and a drive circuit is incorporated as necessary.

(Roll-to-panel type 1st panel manufacturing department)
FIG. 2 shows a roll-to-panel type optical display panel manufacturing system using the roll-shaped first optical film 1. In this embodiment, a liquid crystal cell is used as an optical cell and a liquid crystal display panel is used as an optical display panel.

The roll-shaped first optical film 1 includes a first release film 11, a first pressure-sensitive adhesive layer 12, a first optical functional film 13, and a first surface protection film 14, which 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 (width substantially shorter than the long side of the liquid crystal cell P).

As shown in FIG. 2, the liquid crystal display panel manufacturing system according to the present embodiment has a roll shape on the first surface P1 of the liquid crystal cell P and the first transporting section 81 that transports the liquid crystal cell P to the first attaching section 64. It has the 2nd conveyance part 82 which conveys the liquid crystal cell P after sticking the optical film using the 1st optical film 1. As shown in FIG. Each transport unit is configured to have a plurality of transport rollers R for transporting the liquid crystal cell P by rotating around a rotation axis parallel to the direction orthogonal to the transport direction. In addition to the transport roller, a suction plate or the like may be provided.

(Liquid crystal cell transfer process)
The liquid crystal cell P is arranged in the first transport unit 81 from the storage unit 91 that stores the liquid crystal cell P so that the first surface P1 is the top surface, and is transported to the first sticking unit 64 by the rotation of the transport roller R. It

(First optical film feeding step, first optical film cutting step)
The strip-shaped first optical film 10 unrolled from the roll-shaped first optical film 1 is left without cutting the first release film 11 by the cutting part 61 while adsorbing and fixing the first release film 11 side. The strip-shaped adhesive layer 12, the strip-shaped first optical function film 13, and the strip-shaped first surface protection film 14 have a predetermined size (a length corresponding to the short side of the liquid crystal cell P (a length substantially shorter than the short side). Sa)) and form a notch s. Examples of the cutting by the cutting unit 61 include cutting with a blade (cutting with a cutting blade) and cutting with a laser device. An example of the cut portion s after being cut is shown by an arrow in FIG. 2, but the cut is intentionally drawn large for ease of explanation. A configuration may be adopted in which a nip roller (not shown) is arranged on the upstream side or the downstream side of the cutting section 61 to convey the belt-shaped first optical film 10. The nip rollers may be arranged on the upstream side and the downstream side of the cutting section 61.

(Tension adjustment process)
In the cutting process of the band-shaped first optical film 10 and the subsequent laminating process, a first tension adjusting unit for adjusting the slack of the film in order to enable continuous processing so as not to be interrupted for a long time. 62 is provided. The first tension adjusting unit 62 is configured to have a dancer mechanism using a weight, for example. A nip roller (not shown) may be arranged on the upstream side or the downstream side of the first tension adjusting section 62 to convey the first optical film 10. Note that the nip rollers may be arranged on the upstream side and the downstream side of the first tension adjusting section 62.

(Peeling process)
The first optical film 10 is wound around the first peeling section 63 and inverted, and the first optical film 10 is peeled from the first release film 11. The first release film 11 is wound on a roll by the first winding unit 65. The first winding unit 65 has a roll and a rotation driving unit, and the rotation driving unit rotates the roll to wind the first release film 11 around the roll. Further, a nip roller (not shown) may be arranged on the upstream side or the downstream side of the peeling section 63 to convey the first optical film 10 or the first release film 11. The nip rollers may be arranged on the upstream side and the downstream side of the peeling section 63.

(First attaching step)
While the liquid crystal cell P is being conveyed, the first attaching unit 64 transfers the first optical film 10 from which the first release film 11 has been peeled off to the first surface P1 of the liquid crystal cell P via the first pressure-sensitive adhesive layer 12. Paste it. The 1st sticking part 64 is comprised by a pair of 1st roller 64a and 2nd roller 64b. One of them may be a driving roller and the other may be a driven roller, and both rollers may be driving rollers. The first optical film 10 is attached to the first surface P1 of the liquid crystal cell P by nipping the first optical film 10 and the liquid crystal cell P with a pair of the first roller 64a and the second roller 64b and feeding the same to the downstream side. The liquid crystal cell P after the sheet-shaped first optical film 10 is attached to the first surface P1 of the liquid crystal cell P is transported downstream by the second transport unit 82.

(Sheet-to-panel type second panel manufacturing department)
FIG. 3 shows a sheet-to-panel type optical display panel manufacturing system using the sheet-shaped first optical film 2. In this embodiment, a liquid crystal cell is used as an optical cell and a liquid crystal display panel is used as an optical display panel.

The sheet-shaped first optical film 2 includes a first release film 21, a first pressure-sensitive adhesive layer 22, a first optical functional film 23, a first surface protective film 24, and a second surface protective film, which are laminated in this order. .. As shown in FIG. 1, the sheet-shaped first optical film 2 has a length a and a width b, and has a width corresponding to the long side of the liquid crystal panel (width substantially shorter than the long side of the liquid crystal cell P). ..

As shown in FIG. 3, the liquid crystal display panel manufacturing system according to the present embodiment includes a third transport unit 181 that transports the liquid crystal cell P to the single-wafer sticking device 164 (corresponding to a second sticking unit), and a liquid crystal cell P. Has a fourth transport section 182 for transporting the liquid crystal cell P after the optical film is attached to the first surface P1 of the sheet-shaped first optical film 2. Each transport unit is configured to have a plurality of transport rollers R for transporting the liquid crystal cell P by rotating around a rotation axis parallel to the direction orthogonal to the transport direction. In addition to the transport roller, a suction plate or the like may be provided.

(Liquid crystal cell transfer process)
The liquid crystal cell P is arranged from the storage unit 191 for storing the liquid crystal cell P to the third transport unit 181 so that the first surface P1 is the top surface, and is transported to the single-wafer sticking device 164 by the rotation of the transport roller R. It

The sheet-shaped first optical film 2 is adsorbed by the adsorption section 164a of the sheet-adhering device 164 from the container 100 accommodating the sheet-shaped first optical film 2 and supplied to the laminating position. The first release film 21 is peeled off from the sheet-shaped first optical film 2 by the peeling means. The suction surface of the suction portion 164a has an arcuate cross section. As the peeling means, for example, an adhesive tape may be used to bond the adhesive tape to the surface of the first release film 21 and the first release film 21 may be removed by moving the adhesive tape with a moving mechanism.

The sheet bonding apparatus 164 has a fixing surface 164b, and the fixing surface 164b adsorbs and fixes the first surface P1 side of the liquid crystal cell P. The sheet-shaped second optical film 2 in which the first release film 21 is peeled off and the first pressure-sensitive adhesive layer 22 is exposed is attached to the first surface P1 of the liquid crystal cell P such that the suction portion 164a is rolled.

(Second surface protection film peeling step)
After the sheet-shaped first optical film 2 is attached, the second surface protection film 25 is peeled off. The peeling treatment may be performed manually or with a peeling device.

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

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

In the first and second panel manufacturing departments, an optical inspection may be performed after the optical film is attached to either one side or both sides. The optical film is removed from the liquid crystal cell (optical cell) according to the result of the optical inspection (for example, when the defective cell is determined), and the optical cell is re-installed by the second panel manufacturing unit (sheet-to-panel method). The liquid crystal display panel (optical display panel) may be remanufactured by pasting.

(Modification)
In the present embodiment, the optical film set of the roll-shaped optical film and the sheet-shaped optical film is described for use in the continuous manufacturing method of the liquid crystal display panel, but the present invention is not limited to this, and the continuous organic EL display panel You may use it for a manufacturing method.

In the embodiment, the above optical film is used as the roll-shaped optical film, but the configuration of the roll-shaped optical film is not limited to this. For example, except for the release film, a band-shaped optical film having a plurality of cut lines formed in the width direction may be wound (cut optical film).

In the embodiment, the strip-shaped optical film was cut at a predetermined interval in the width direction (half-cut), but from the viewpoint of improving the yield, the strip-shaped optical film is cut in the width direction so as to avoid the defective portion of the strip-shaped optical film. May be cut (skip cut), or the optical film including the defective portion may be cut into a size smaller than a predetermined interval (size of optical cell) (more preferably, as small as possible).

In the embodiments, the description has been given by taking the horizontally long rectangular liquid crystal cell and the liquid crystal display panel as an example, but the shape of the liquid crystal cell and the liquid crystal display panel has another pair of opposite sides and another pair of opposite sides. There is no particular limitation as long as it has a shape.

1 Roll-shaped optical film 11 Release film 12 Adhesive layer 13 Optical function film 14 First surface protection film 2 Sheet-shaped optical film 21 Release film 22 Adhesive layer 23 Optical function film 24 First surface protection film 25 2 Surface protection film

Claims (6)

Using a roll-shaped optical film formed by winding a band-shaped optical film, the first bonding step of bonding the optical film to at least one surface of the optical cell to form an optical display panel Panel manufacturing process,
A method for manufacturing an optical display panel, comprising: a second panel manufacturing step including a second bonding step in which a sheet-shaped optical film is bonded to at least one surface of the optical cell to form an optical display panel,
In the first attaching step,
The release film is peeled off from the strip-shaped optical film that is fed from the roll-shaped optical film and has a configuration in which a release film, a pressure-sensitive adhesive layer, an optical functional film, and a first surface protection film are laminated in this order. Via the adhesive layer exposed by the above, the optical film is attached to the at least one surface of the optical cell,
In the second attaching step,
The release film is peeled from the sheet-shaped optical film having a configuration in which the release film, the pressure-sensitive adhesive layer, the optical functional film, the first surface protection film, and the second surface protection film are laminated in this order. Via the exposed adhesive layer, the sheet-shaped optical film is attached to the at least one surface of the optical cell,
In the second panel manufacturing process,
A second surface protection film peeling step of peeling the second surface protecting film from the optical film of the sheet form of the state of being stuck to the optical cell, seen including,
The first surface protective film has a pressure-sensitive adhesive layer, or is a self-adhesive type,
The second surface protection film has a pressure-sensitive adhesive layer or is a self-adhesive type,
The first surface protection film and the second surface protection film have the same configuration,
The magnitude relationship of the peeling force between the layers in the sheet-shaped optical film is the peeling force A between the release film and the pressure-sensitive adhesive layer, the peeling force B between the pressure-sensitive adhesive layer and the optical function film, and When the interlayer peeling force C between the optical functional film and the first surface protective film and the interlayer peeling force D between the first surface protective film and the second surface protective film are A<D<C<B. Yes,
The optical functional film of the sheet-shaped optical film is a polarizing film having a thickness of 60 μm or less, and the polarizing film has a polarizer having a thickness of 10 μm or less,
Manufacturing method of optical display panel. In the first attaching step,
A cutting step of cutting the strip-shaped optical film fed from the roll-shaped optical film, leaving the release film in a direction orthogonal to the longitudinal direction of the optical film,
The manufacturing method of the optical display panel of Claim 1 including the peeling process which peels the said release film from the said optical film. The strip-shaped optical film, notches are formed at predetermined intervals except the release film,
In the first attaching step,
The method of manufacturing an optical display panel according to claim 1, further comprising a peeling step of peeling the release film by folding the release film inward from the optical film fed from the roll-shaped optical film. A roll-shaped optical film formed by winding a band-shaped optical film, and a first bonding part that bonds the optical film to at least one surface of an optical cell to form an optical display panel. Panel manufacturing department,
A system for manufacturing an optical display panel, comprising: a second panel manufacturing unit including a second bonding unit that bonds a sheet-shaped optical film to form an optical display panel on at least one surface of an optical cell,
The first pasting section,
The release film is peeled off from the strip-shaped optical film that is fed from the roll-shaped optical film and has a configuration in which a release film, a pressure-sensitive adhesive layer, an optical functional film, and a first surface protection film are laminated in this order. Via the adhesive layer exposed by the above, the optical film is attached to the at least one surface of the optical cell,
The second pasting section,
The release film is peeled from the sheet-shaped optical film having a configuration in which the release film, the pressure-sensitive adhesive layer, the optical functional film, the first surface protection film, and the second surface protection film are laminated in this order. Via the exposed adhesive layer, the sheet-shaped optical film is attached to the at least one surface of the optical cell,
The second panel manufacturing department
A second surface protection film peeling section for peeling the second surface protection film from the sheet-shaped optical film attached to the optical cell,
The first surface protective film has a pressure-sensitive adhesive layer, or is a self-adhesive type,
The second surface protective film has a pressure-sensitive adhesive layer, or is a self-adhesive type,
The magnitude relationship of the peeling force between the layers in the sheet-like optical film is the interlayer peeling force A between the release film and the pressure-sensitive adhesive layer, the interlayer peeling force B between the pressure-sensitive adhesive layer and the optical functional film, and When the interlayer peeling force C between the optical functional film and the first surface protective film and the interlayer peeling force D between the first surface protective film and the second surface protective film are A<D<C<B. Yes,
The optical functional film of the sheet-shaped optical film is a polarizing film having a thickness of 60 μm or less, and the polarizing film has a polarizer having a thickness of 10 μm or less,
Optical display panel manufacturing system. The first pasting section,
The strip-shaped optical film fed out from the roll-shaped optical film, a cutting portion for cutting leaving the release film in a direction orthogonal to the longitudinal direction of the optical film,
The manufacturing system of the optical display panel according to claim 4, further comprising a peeling portion that peels the release film from the optical film. The strip-shaped optical film, notches are formed at predetermined intervals except the release film,
The first pasting section,
The optical display panel manufacturing system according to claim 4, further comprising a peeling portion that peels the release film from the optical film fed from the roll-shaped optical film by folding the release film inward.

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