JP2018013729A - Sheet-like optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet-like optical film that, in laminating a thin optical functional film on an optical cell, can suitably manufacture an optical display panel having the same composition even when both a roll-to-panel method and a sheet-to-panel method are used.SOLUTION: A sheet-like optical film 2 has a mold release film 21, an adhesive layer 22, an optical functional film 23, a first surface protective film 24, and a second surface protective film 25 laminated in this order. When the interlayer peeling force between the mold release film and adhesive layer is A, the interlayer peeling force between the adhesive layer and optical functional film is B, the interlayer peeling force between the optical functional film and first surface protective film is C, and the interlayer peeling force between the first surface protective film and the second surface protective film is D, the magnitude relationships between the interlayer peeling forces in the sheet-like optical film 2 are A<B, A<C, and A<D.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sheet-like optical film, for example, a sheet-like optical film used in sheet-to-panel manufacturing equipment.

  An optical film in which a release film, an adhesive layer, an optical functional film (typically, a polarizing film) and a surface protective film are laminated in this order is formed in a roll shape. An optical film obtained by cutting the optical film fed from the roll-shaped optical film by cutting the adhesive layer, the optical functional film and the surface protective film in the width direction (half cut) while leaving the release film. (Hereinafter also referred to as “roll-to-panel method”) in which the release film is peeled off and the optical film is bonded to the optical cell through the exposed adhesive layer (for example, Patent Documents 1 and 2). reference).

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

JP 2011-123208 A Japanese Patent Laying-Open No. 2015-049115 JP 2006-039238 A

  By the way, at the manufacturing site of optical display panels such as liquid crystal display panels, there is a new case of manufacturing optical display panels with the same configuration using not only the roll-to-panel method but also the sheet-to-panel method. It has occurred. For example, Patent Document 2 discloses that an optical display panel is continuously manufactured using a roll-to-panel method, and a rework process is performed on the optical display panel determined to be defective. When not many defective products are generated, it is conceivable to use a sheet-to-panel method when a new optical functional film is bonded to the optical cell in the rework process. Also, for example, when optical display panels with the same configuration must be produced in large quantities in a short period of time, the roll-to-panel method cannot cover all supply amounts, and the sheet-to-panel method is used together. Is also possible.

  In recent years, as the thickness of optical display panels has been reduced, optical functional films (for example, a polarizing film having a thickness of 60 μm or less) including a polarizing film are being developed. Such a thin optical functional film has a low waist (elastic modulus) and is likely to be twisted or curled.

  According to the roll-to-panel method, a thin optical functional film is transported to a bonding position in a state of being laminated on a carrier film (release film), and the optical function from the carrier film (release film) at the bonding position. Since the film is peeled off and the optical functional film is bonded to the optical cell, a thin optical functional film can be continuously bonded to the optical cell while suppressing the occurrence of twisting and curling. However, in the sheet-to-panel system, handling such as transporting the optical functional film in a single wafer state, peeling of the release film, and laminating processing of the optical functional film to the liquid crystal cell is difficult, resulting in poor bonding. There is concern about a drop in yield.

  The present invention is a sheet capable of suitably producing an optical display panel having the same configuration even when a roll-to-panel method and a sheet-to-panel method are used together when a thin optical functional film is bonded to an optical cell. An object is to provide a leaf-like optical film.

The present invention is a sheet-like optical film in which a release film, an adhesive layer, an optical functional film, a first surface protective film and a second surface protective film are laminated in this order,
The magnitude relationship of the peeling force between each layer in the sheet-like optical film is
Delamination force A between the release film and the adhesive layer,
Delamination force B between the adhesive layer and the optical functional film,
Delamination force C between the optical functional film and the first surface protective film,
In the case of the delamination force D between the first surface protective film and the second surface protective film,
A <B, A <C, A <D.

  In the above invention, the magnitude relationship of the peeling force is preferably A <D <C ≦ B or A <D <B ≦ C, and more preferably A <D <C <B.

  In the above invention, the optical functional film may be a polarizing film.

  In the above invention, the polarizing film may have a thickness of 60 μm or less.

  In the above invention, the polarizing film may have a polarizer having a thickness of 10 μm or less.

  In the above invention, the first surface protective film may have a first base film and a first pressure-sensitive adhesive layer, and may be laminated on the optical functional film via the first pressure-sensitive adhesive layer.

  In the above invention, the first surface protective film may be a self-adhesive film.

  In the above invention, the second surface protective film may have a second base film and a second pressure-sensitive adhesive layer, and may be laminated on the first surface protective film via the second pressure-sensitive adhesive layer. .

  In the above invention, the second surface protective film may be a self-adhesive film.

  The sheet-like optical film of the present invention is used in a sheet-to-panel system. Since the sheet-like optical film provided with the second surface protective film has improved handling properties, the sheet-to-panel method can be used while suppressing the occurrence of twisting and curling. It can be suitably bonded to the cell. And by removing (for example, peeling) the second surface protective film from the sheet-like optical film bonded to the optical display panel, as a result, the same as the optical display panel manufactured by the roll-to-panel method A laminated optical display panel can be manufactured. That is, according to the sheet-like optical film of the present invention, when the optical film is bonded to the optical cell, even when the roll-to-panel method and the sheet-to-panel method are used in combination, A display panel can be suitably manufactured.

The schematic diagram which shows the optical film set of Embodiment 1. Schematic diagram of roll-to-panel manufacturing system Schematic diagram of sheet-to-panel manufacturing system

<Sheet optical film>
First, a set of a sheet-like optical film and a roll-like optical film used in the present invention will be described. FIG. 1 is a schematic view showing a sheet-like optical film and a roll-like optical film. The side surface, plane, and partial cross-sectional enlarged view of the roll-shaped first optical film 1 are shown in the upper part of FIG. The side surface, plane, and partial cross-sectional enlarged view of the sheet-like first optical film 2 are shown in the lower part of FIG. In the roll-shaped first optical film 1, a first release film 11, a first pressure-sensitive adhesive layer 12, a first optical functional film 13, and a first surface protective film 14 are laminated in this order.

  The roll-shaped first optical film 1 is used for manufacturing an optical display panel by a roll-to-panel method. In such a case, the strip-shaped first optical film 10 having a width a that is fed out from the roll-shaped first optical film 1 is cut by the cutting means C leaving the release film 11 at a predetermined interval b. Reference numeral s denotes a cut formed in the first optical film 10 by the above cutting.

  Further, the sheet-like 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 25 laminated in this order. Has been. The size of the sheet-like first optical film 2 is vertical a and horizontal b. The sheet-like first optical film 2 is used for manufacturing an optical display panel by a sheet-to-panel method.

  In the present embodiment, the first release film 11 and the first release film 21 have the same configuration. The 1st adhesive layer 12 and the 1st adhesive layer 22 are the same structures. The first optical functional film 13 and the first optical functional film 23 have the same configuration. The 1st surface protection film 14, the 1st surface protection film 24, and the 2nd surface protection film 25 are the same structures. The “same configuration” is not limited as long as the materials, thicknesses, and the like completely match, but may be substantially the same (for example, the same in terms of manufacturing quality).

  In the present embodiment, the first surface protective film 14 (or 24) has a first base film and a first pressure-sensitive adhesive layer, and the first optical functional film 13 (or 23) via the first pressure-sensitive adhesive layer. ). As another embodiment, the first surface protective film 14 (or 24) may be a self-adhesive film.

  In this embodiment, the 2nd surface protection film 25 has a 2nd base film and a 2nd adhesive layer, and is laminated | stacked on the 1st surface protection film 24 through the said 2nd adhesive layer. As another embodiment, the second surface protective film 25 may be a self-adhesive film.

(Relationship between phase peeling forces)
Further, the peeling force between the first surface protective film 24 and the first optical functional film 23 is larger than the peeling force between the second surface protective film 25 and the first surface protective film 24. According to this, the 2nd surface protection film 25 can be peeled more smoothly. As the measurement of the peeling force, for example, a tensile tester can be used. The peeling condition is measured by 180 ° peeling at 0.3 m / min. The peeling force is controlled by the composition and thickness of the pressure-sensitive adhesive.

The magnitude relationship of the peeling force between each layer in the sheet-like 1st optical film 2 is as follows.
Delamination force A between the first release film 21 and the first pressure-sensitive adhesive layer 22;
Delamination force B between the first pressure-sensitive adhesive layer 22 and the first optical functional film 23,
Delamination force C between the first optical functional film 23 and the first surface protective film 24;
In the case of the delamination force D between the first surface protective film 24 and the second surface protective film 25,
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, the second surface protective film can be prevented from peeling off when the first release film is peeled off.

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

(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 a polarizing film, for example, (1) a configuration in which protective films (sometimes referred to as “polarizer protective films”) are laminated on both sides of a polarizer (sometimes referred to as “both protective polarizing films”). (2) A structure in which a protective film is laminated only on one side of a polarizer (sometimes referred to as a “single protective polarizing film”).

(Polarizer)
A polarizer using a polyvinyl alcohol-based resin is used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic material such as iodine is preferable.

  A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol in an aqueous solution of iodine and stretching it 3 to 7 times the original length. If necessary, it may contain boric acid, zinc sulfate, zinc chloride, or the like, or may be immersed in an aqueous solution such as potassium iodide. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with dirt and anti-blocking agents by washing the polyvinyl alcohol film with water, it also has the effect of preventing unevenness such as uneven coloring by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution such as boric acid or potassium iodide or in a water bath.

  The thickness of the polarizer is preferably 10 μm or less from the viewpoint of thinning, more preferably 8 μm or less, further 7 μm or less, and further preferably 6 μm or less. On the other hand, the thickness of the polarizer is preferably 2 μm or more, and more preferably 3 μm or more. Such a thin polarizer has less thickness unevenness, excellent visibility, and less dimensional change, and therefore 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 waist (elastic modulus), and therefore, there is a high possibility of twisting and curling in the sheet-to-panel system. Therefore, the present invention is particularly suitable for the polarizing film.

As a thin polarizer, typically,
Patent No. 4751486,
Japanese Patent No. 4751481,
Patent No. 4815544,
Patent No. 5048120,
International Publication No. 2014/077599 pamphlet,
International Publication No. 2014/077636 Pamphlet,
And the thin polarizers obtained from the production methods described therein.

The polarizer has an optical property represented 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 to be configured to satisfy the above condition. A polarizer configured so as to satisfy the above-described conditions uniquely has performance 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 luminance is 500 cd / m ² or more. As other uses, for example, it is bonded to the viewing side of the organic EL cell.

  As the thin polarizer, among the production methods including the step of stretching in the state of a laminate and the step of dyeing, Patent No. 4751486, Patent, in that it can be stretched at a high magnification and the polarization performance can be improved. What is obtained by the manufacturing method including the process of extending | stretching in a boric-acid aqueous solution as described in the 4751481 specification and the patent 4815544 specification is preferable, and it describes especially in the patent 4751481 specification and the patent 4815544 specification. What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary before extending | stretching in the boric-acid aqueous solution which has this 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 laminated state and a step of dyeing. With this manufacturing method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching by being supported by the stretching resin substrate.

(Protective film (polarizer protective film))
As a material constituting the protective film, a material excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is preferable. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, styrene such as polystyrene and acrylonitrile / styrene copolymer (AS resin) And polymers based on polycarbonate and polycarbonate. In addition, 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 , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy polymer, or the above Polymer blends and the like can also be mentioned as examples of the polymer forming the protective film.

  In addition, 1 or more types of arbitrary appropriate additives may be contained in the protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, a coloring inhibitor, 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, still more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. . When content of the said thermoplastic resin in a transparent protective film is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has cannot fully be expressed.

  As the protective film, a retardation film, a brightness enhancement film, a diffusion film, and 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 can 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, antireflection layer, antisticking layer, diffusion layer and antiglare layer can be provided on the transparent protective film itself, and separately provided separately from the transparent protective film. You can also.

(Intervening layer)
The protective film and the polarizer are laminated via an intervening layer such as an adhesive layer, an adhesive layer, and an undercoat layer (primer layer). At this time, it is desirable that the both are laminated without an air gap by an intervening layer.
The adhesive layer is formed of an adhesive. The type of the 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. Examples of the adhesive include water-based, solvent-based, hot-melt-based, active energy ray-curable types, and the like. Or an active energy ray hardening-type adhesive agent is suitable.
Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex, and a water-based polyester. The water-based adhesive is usually used as an adhesive made of an aqueous solution, and usually contains 0.5 to 60% by weight of a solid content.
The active energy ray curable adhesive is an adhesive that cures by an active energy ray such as an electron beam and ultraviolet rays (radical curable type and cationic curable type). Can be used. As the active energy ray curable adhesive, for example, a photo radical curable adhesive can be used. When the photo radical curable active energy ray curable adhesive is used as an ultraviolet curable adhesive, the adhesive contains a radical polymerizable compound and a photo polymerization initiator.

  In addition, in lamination | stacking of a polarizer and a protective film, an easily bonding layer can be provided between a transparent protective film and an adhesive bond layer. The easy adhesion layer can be formed of, for example, 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, and the like. These polymer resins can be used alone or in combination of two or more. Moreover, you may add another additive for formation of an easily bonding layer. Specifically, a stabilizer such as a tackifier, an ultraviolet absorber, an antioxidant, and a heat resistance stabilizer may be used.

  The pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive. Various pressure-sensitive adhesives can be used as the pressure-sensitive adhesive, such as 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, Examples include acrylamide-based adhesives and cellulose-based adhesives. An adhesive base polymer is selected according to the type of the adhesive. Among the pressure-sensitive adhesives, acrylic pressure-sensitive adhesives are preferably used because they are excellent in optical transparency, exhibit appropriate wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and are excellent in weather resistance and heat resistance. The

  The undercoat layer (primer layer) is formed in order to improve the adhesion between the polarizer and the protective film. The material constituting the primer layer is not particularly limited as long as the material 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 an acrylic resin, a polyolefin resin, a polyester resin, a polyvinyl alcohol resin, or a mixture thereof.

(Surface protection film)
A 1st, 2nd surface protection film is provided in the single side | surface (surface which has not laminated | stacked the adhesive layer) in a polarizing film in an optical film, and protects optical function films, such as a polarizing film.
As the base film of the first and second surface protective films, a film material having isotropic property or close to isotropic property is selected from the viewpoints of inspection property and manageability. Examples of film materials include polyester resins such as polyethylene terephthalate film, cellulose resins, acetate resins, polyether sulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, acrylic resins, and the like. Examples thereof include transparent polymers such as resins. Of these, polyester resins are preferred. The base film can be used as a laminate of one kind or two or more kinds of film materials, and a stretched product of the film can also be used. The thickness of the base film is preferably 10 μm to 150 μm, more preferably 20 to 100 μm.

  As the first and second surface protective films, the base film can be used as a self-adhesive film, and a film having the base film and an adhesive layer can be used. As the first and second surface protective films, those having an adhesive layer are preferably used from the viewpoint of protecting an optical functional film such as a polarizing film.

  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. A pressure-sensitive adhesive as a base polymer can be appropriately selected and used. From the viewpoints of transparency, weather resistance, heat resistance and the like, an acrylic pressure-sensitive adhesive having an acrylic polymer as a base polymer is preferable. The thickness (dry film thickness) of the pressure-sensitive adhesive layer is determined according to the required adhesive force. Usually, it is about 1-100 micrometers, Preferably it is 5-50 micrometers.

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

<Adhesive layer>
An appropriate pressure-sensitive adhesive can be used for forming the pressure-sensitive adhesive layers 12 and 22, and the type thereof is not particularly limited. Adhesives include rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinyl pyrrolidone adhesives, polyacrylamide adhesives, Examples thereof include cellulose-based pressure-sensitive adhesives.

  Among these pressure-sensitive adhesives, those having excellent optical transparency, suitable wettability, cohesiveness, and adhesive pressure-sensitive adhesive properties, and excellent weather resistance and heat resistance are preferably used. An acrylic pressure-sensitive adhesive is preferably used as one exhibiting such characteristics.

  As a method for forming the pressure-sensitive adhesive layers 12 and 22, for example, a release film obtained by removing the pressure-sensitive adhesive (applying to a separator or the like, drying and removing a polymerization solvent or the like to form a pressure-sensitive adhesive layer, and a polarizer) (Or transparent protective film) or a method of applying the pressure-sensitive adhesive to a polarizer (or transparent protective film) and drying and removing the polymerization solvent to form a pressure-sensitive adhesive layer on the polarizer. In applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be added as appropriate.

  As the release film subjected to the release treatment, a silicone release liner is preferably used. In the step of forming the pressure-sensitive adhesive layer by applying and drying the pressure-sensitive adhesive of the present invention on such a liner, an appropriate method may be adopted as appropriate according to the purpose. Preferably, a method of heating and drying the coating film is used. The heat 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 within the above range, an adhesive having excellent 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
It is 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 thereof include an extrusion coating method.

  The thickness of the 1st adhesive layers 12 and 22 is not restrict | limited in particular, For example, it is about 1-100 micrometers. Preferably, it is 2-50 micrometers, More preferably, it is 2-40 micrometers, More preferably, it is 5-35 micrometers.

<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 nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof. However, a plastic film is preferably used from the viewpoint of excellent surface smoothness.

  The plastic film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer. For example, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, and a vinyl chloride co-polymer are used. Examples thereof include a polymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

  The thickness of the 1st release films 11 and 21 is 5-200 micrometers normally, Preferably it is about 5-100 micrometers. For the separator, if necessary, mold release and antifouling treatment with a silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, silica powder, etc., coating type, kneading type, vapor deposition type It is also possible to carry out antistatic treatment such as. In particular, the release property from the pressure-sensitive adhesive layer can be further improved by appropriately performing a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment on the surface of the release film.

(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 (viewing side surface) Pa and a second substrate (back surface) Pb) disposed to face 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 achieve high contrast. A liquid crystal display panel has a polarizing film bonded to one 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 configuration in which an electroluminescent layer is sandwiched between a pair of electrodes. As the organic EL cell, for example, an arbitrary type such as a top emission method, a bottom emission method, a double emission method, or the like can be used. The organic EL display panel has a polarizing film bonded to one or both sides of an organic EL cell, and a drive circuit is incorporated as necessary.

(Roll-to-panel manufacturing system)
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 will be described as an example of an optical cell, and a liquid crystal display panel will be described as an example of an optical display panel.

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

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

(Liquid crystal cell transport process)
The liquid crystal cell P is disposed 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 pasting unit 64 by the rotation of the transport roller R. The

(First optical film feeding step, first optical film cutting step)
The strip-shaped first optical film 10 drawn out from the roll-shaped first optical film 1 is left without cutting the first release film 11 at the cutting portion 61 while adsorbing and fixing the first release film 11 side. The strip-shaped pressure-sensitive adhesive layer 12, the strip-shaped first optical functional film 13, and the strip-shaped first surface protective film 14 are of a predetermined size (length corresponding to the short side of the liquid crystal cell P (substantially shorter than the short side). )) To form a cut portion s. Examples of the cutting by the cutting unit 61 include cutting using a blade (cutting with a cutting blade) and cutting with a laser device. An example of the cut portion s after being cut is indicated by an arrow in FIG. 2, but the cut is deliberately drawn for easy explanation. A configuration in which a nip roller (not shown) is arranged on the upstream side or the downstream side of the cutting unit 61 and conveys the belt-shaped first optical film 10 may be adopted. Note that nip rollers may be arranged on the upstream side and the downstream side of the cutting portion 61.

(Tension adjustment process)
A first tension adjusting unit for enabling continuous processing so that the processing is not interrupted for a long time in the cutting processing of the strip-shaped first optical film 10 and the subsequent sticking processing and for adjusting the slackness of the film. 62 is provided. The first tension adjusting unit 62 includes a dancer mechanism using a weight, for example. A configuration in which a nip roller (not shown) is disposed on the upstream side or the downstream side of the first tension adjusting unit 62 and conveys the first optical film 10 may be employed. Note that the nip rollers may be arranged on the upstream side and the downstream side of the first tension adjusting unit 62.

(Peeling process)
The first optical film 10 is wound around the first peeling portion 63 and reversed, 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 1st winding part 65 has a roll and a rotation drive part, and winds the 1st release film 11 to a roll, when a rotation drive part rotates a roll. Moreover, the structure which a nip roller not shown is arrange | positioned in the upstream or downstream of the peeling part 63, and conveys the 1st optical film 10 or the 1st release film 11 may be sufficient. Note that the nip rollers may be disposed on the upstream side and the downstream side of the peeling portion 63.

(First sticking step)
The first pasting portion 64 conveys the liquid crystal cell P while the first optical film 10 from which the first release film 11 has been peeled off the first surface P1 of the liquid crystal cell P via the first adhesive layer 12. And paste. The 1st sticking part 64 is comprised by a pair of 1st roller 64a and the 2nd roller 64b. Either one 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 affixed to the first surface P1 of the liquid crystal cell P by feeding the first optical film 10 and the liquid crystal cell P while sandwiching the first optical film 10 and the liquid crystal cell P by the pair of first roller 64a and second roller 64b. 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 manufacturing system)
FIG. 3 shows a manufacturing system of a sheet-to-panel type optical display panel using the sheet-like first optical film 2. In this embodiment, a liquid crystal cell will be described as an example of an optical cell, and a liquid crystal display panel will be described as an example of an optical display panel.

  In the sheet-like first optical film 2, 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 are laminated in this order. . As shown in FIG. 1, the sheet-like first optical film 2 is longitudinally a and laterally b, and has a width corresponding to the long side of the liquid crystal panel (substantially shorter than the long side of the liquid crystal cell P). .

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

(Liquid crystal cell transport process)
From the storage unit 191 that stores the liquid crystal cell P, the liquid crystal cell P is disposed on the third transport unit 181 so that the first surface P1 is the top surface, and is transported to the single wafer pasting device 164 by the rotation of the transport roller R. The

  From the container 100 in which the sheet-like 1st optical film 2 was accommodated, the sheet-like 1st optical film 2 is made to adsorb | suck with the adsorption | suction part 164a of the sheet | seat sticking apparatus 164, and is supplied to a bonding position. The first release film 21 is peeled off from the sheet-like first optical film 2 by a peeling means. The suction surface of the suction part 164a has a circular arc cross section. For example, the peeling means may peel off the first release film 21 by sticking the adhesive tape to the surface of the first release film 21 using an adhesive tape and moving the adhesive tape with a moving mechanism.

  The single wafer pasting 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. The sheet-like second optical film 2 in a state where the first release film 21 is peeled and the first pressure-sensitive adhesive layer 22 is exposed is pasted on the first surface P1 of the liquid crystal cell P so as to roll the adsorption portion 164a.

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

  In the roll-to-panel manufacturing system (FIG. 2), the optical film is attached to the one surface (first surface P1) of the liquid crystal cell by the roll-to-panel method, but the present invention is not limited to this. An 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 sheet-to-panel manufacturing system (FIG. 3), the optical film is attached to the one surface (first surface P1) of the liquid crystal cell by the sheet-to-panel method, but the present invention is not limited to this. An 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 roll-to-panel manufacturing system and the sheet-to-panel manufacturing system, an optical inspection may be performed after the optical film is attached to one or both surfaces. Depending on the result of the optical inspection (for example, when a defective product is determined), the optical film is removed from the liquid crystal cell (optical cell), and the optical cell is again mounted in 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 use of the roll-shaped optical film and the sheet-shaped optical film optical film set for the continuous manufacturing method of the liquid crystal display panel has been described. You may use for a manufacturing method.

  In the embodiment, the above-described 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 a release film, you may use what wound the strip | belt-shaped optical film in which the several cut line was formed in the width direction (optical film with a notch).

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

  In the embodiment, the description has been given by taking a horizontally long liquid crystal cell and a liquid crystal display panel as examples. However, the shape of the liquid crystal cell and the liquid crystal display panel has another set of sides facing each other and another set of sides facing each other. As long as it is a shape, it is not particularly limited.

DESCRIPTION OF SYMBOLS 1 Roll-shaped optical film 11 Release film 12 Adhesive layer 13 Optical function film 14 1st surface protection film 2 Sheet-like optical film 21 Release film 22 Adhesive layer 23 Optical function film 24 1st surface protection film 25 1st 2 Surface protective film

Claims (10)

A release film, a pressure-sensitive adhesive layer, an optical functional film, a first surface protective film and a second surface protective film are laminated sheet films in this order,
The magnitude relationship of the peeling force between each layer in the sheet-like optical film is
Delamination force A between the release film and the adhesive layer,
Delamination force B between the adhesive layer and the optical functional film,
Delamination force C between the optical functional film and the first surface protective film,
In the case of the delamination force D between the first surface protective film and the second surface protective film,
A sheet-like optical film in which A <B, A <C, and A <D. The magnitude relationship of the peeling force is
The sheet-like optical film according to claim 1, wherein A <D <C ≦ B or A <D <B ≦ C. The magnitude relationship of the peeling force is
The sheet-like optical film according to claim 2, wherein A <D <C <B.   The sheet-like optical film according to claim 1, wherein the optical functional film is a polarizing film.   The sheet-like optical film according to claim 4, wherein the polarizing film has a thickness of 60 μm or less.   The sheet-like optical film according to claim 4, wherein the polarizing film has a polarizer having a thickness of 10 μm or less.   The said 1st surface protection film has a 1st base film and a 1st adhesive layer, and is laminated | stacked on the said optical function film through the said 1st adhesive layer. The sheet-like optical film according to any one of 6.   The sheet-like optical film according to claim 1, wherein the first surface protective film is a self-adhesive film.   The said 2nd surface protection film has a 2nd base film and a 2nd adhesive layer, and is laminated | stacked on the said 1st surface protection film through the said 2nd adhesive layer. The sheet-like optical film of any one of 1-8. The sheet-like optical film according to any one of claims 1 to 8, wherein the second surface protective film is a self-adhesive film.

Images