JP7158438B2 - OPTICAL MEMBER MANUFACTURING METHOD AND MANUFACTURING APPARATUS - Google Patents

Description

The present invention relates to an optical member manufacturing method and manufacturing apparatus.

2. Description of the Related Art Conventionally, an optical member including an optical film such as a polarizer and an adhesive layer has been known.
As a method for obtaining an optical member of a desired size, cutting a raw laminate having an optical film and an adhesive layer with a laser or a blade is known (see Patent Documents 1 and 2).

WO2014/189078 JP 2009-86675 A

By the way, in recent years, demands for dimensional accuracy for optical members using optical films and pressure-sensitive adhesive layers have become stricter. Therefore, it is difficult to obtain the desired dimensional accuracy simply by cutting the raw fabric laminate. Therefore, in some cases, the end face of the laminated body after cutting is processed by grinding and polishing.

However, when the end face of the laminate is subjected to processing such as polishing, powder such as polishing dust sometimes adheres to the end face of the laminate. If the powder remains in the laminate, the final product including the laminate is unfavorably contaminated.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and an apparatus for manufacturing an optical member to which powder such as polishing dust adheres less.

A method for manufacturing an optical member according to the present invention includes preparing a laminate having an optical film and an adhesive layer provided on one surface of the optical film and having powder adhered to an end surface of the optical film. a step (preparation step); and a step (collision step) of removing the powder from the end face of the laminate by causing dry ice particles to collide with the end face.

According to the present invention, dry ice particles are used to suitably remove powder such as shavings, cutting shavings, and polishing shavings from the end face of the laminate (optical member).

Here, the dry ice particles may have an average particle size of 100 to 1000 μm.

As a result, chipping of the adhesive on the end face is suppressed while powder such as grinding dust is preferably removed.

Further, in the collision step, the dry ice particles can collide with an end face of a laminated structure in which a plurality of the laminated bodies are laminated.

According to this, mass processing of the laminate becomes possible.

Further, at the same time that the dry ice particles collide with a part of the end face, at least one selected from the group consisting of cutting, cutting, and polishing is performed on the other part of the end face of the laminate. can be done.

According to this, it is possible to shorten the process time by performing a plurality of processes in parallel.

In addition, in the preparation step, the end face is subjected to at least one treatment selected from the group consisting of cutting, cutting, and polishing, and when the dry ice particles collide with a part of the end face, the end face is Any treatment selected from the above group may not be performed on it.

According to this, the atmosphere (space) in which the powder is removed by the collision of the dry ice particles can be separated from the atmosphere (space) in which the powder is generated. It is possible to suppress the contamination of the part where the dry ice hits.

The optical film is at least one selected from the group consisting of a polarizer, a protective film, a retardation film, a brightness enhancement film, a window film, and a touch sensor, and a laminate containing two or more at least one selected from the group. It can be a film, or a laminated film containing at least two selected from the above group.

The relative humidity of the atmosphere in the impingement step may be 30-75%.

An apparatus for manufacturing an optical member according to the present invention includes an end surface processing unit that cuts, cuts, or polishes an end surface of an optical film and a laminate having an adhesive layer provided on one surface of the optical film; and a dry ice particle supply unit that causes dry ice particles to collide with the portion of the laminate that has been processed into the end surface processed portion.

The apparatus for manufacturing an optical member may further include a conveying section for moving the laminate between the end surface processing section and the dry ice particle supply section.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method and manufacturing apparatus of an optical member with little adhesion of powders, such as grinding|polishing dust, can be provided.

(a) and (b) of FIG. 1 are cross-sectional views of a laminate 100 according to one embodiment of the present invention. (a) and (b) of FIG. 2 are cross-sectional views of other examples of the laminate, respectively. FIG. 3 is a schematic configuration diagram of a dry ice particle supply unit. FIG. 4 is a conceptual diagram showing how dry ice particles collide with the end face of a laminated structure 120 including a plurality of laminated bodies 100. FIG. FIG. 5 is a perspective view of an optical member manufacturing apparatus according to an embodiment of the present invention. FIG. 6 is a perspective view showing another example of the end surface processed portion in FIG. FIG. 7 is a conceptual diagram showing how dry ice particles collide with the inner end surface of the laminated structure 120 having the through holes H'.

An optical member manufacturing method and manufacturing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(Preparation of laminate with powder adhering to the end faces)
First, as shown in (a) of FIG. 1, a laminate having an optical film 50 and an adhesive layer 80 provided on one surface of the optical film 50 and having powder f adhered to the end surface E thereof. Prepare 100. Note that the end surface E is not limited to the outer end surface of the laminate 100 . For example, as shown in FIG. 1(b), when the laminate 100 has a hole H penetrating in the lamination direction, the inner wall of the hole H, that is, the inner end surface E of the laminate 100, is also covered with drilling debris. Powder f may adhere.

(optical film)
The optical film 50 is a film that transmits at least part of visible light.
Examples of the optical film 50 are polarizers, protective films, retardation films, brightness enhancement films, window films, touch sensors, and the optical film 50 may have a laminated structure having a plurality of single types of these films. It may well have a laminated structure with multiple types of these films.

(Polarizer)
A polarizer is a film in which the transmittance of linearly polarized light is different in two orthogonal in-plane directions. As the material for the polarizer, known materials that have been used in the manufacture of polarizers can be used. Examples include polyvinyl alcohol resin, polyvinyl acetate resin, ethylene/vinyl acetate (EVA) resin, and polyamide resin. , polyester-based resins, and the like. Polyvinyl alcohol-based resins are particularly preferred. A film-like polarizer (film-type polarizer) can be obtained by stretching these resin films, then dyeing them with iodine or a dichroic dye, and subjecting them to boric acid treatment.

The thickness of the film-type polarizer can be, for example, 1-75 μm.

Another example of the polarizer may be a liquid crystal coated polarizer formed from a liquid crystalline compound. This liquid crystal-coated polarizer can be produced, for example, by using an appropriate base material and coating the liquid crystal polarizing composition on this base material. An alignment film may be formed on this substrate before applying the liquid crystal polarizing composition. The liquid crystal polarizing composition may include a liquid crystal compound and a dichroic dye compound. The liquid crystalline compound may have a property of exhibiting a liquid crystal state, and in particular, should have a high-order liquid crystal state such as a smectic phase, so that the resulting liquid crystal coated polarizer exhibits high polarizing performance. It is preferable because it can be demonstrated. It is also preferable that the liquid crystalline compound has a polymerizable functional group. The dichroic dye compound is a dye that exhibits dichroism by aligning with the liquid crystal compound, and the dichroic dye itself may have liquid crystallinity or may have a polymerizable functional group. can also be Any compound contained in the liquid crystal polarizing composition preferably has a polymerizable functional group. The liquid crystal polarizing composition may further include initiators, solvents, dispersants, leveling agents, stabilizers, surfactants, cross-linking agents, silane coupling agents, and the like.

Here, a typical example of a method for producing a liquid crystal coated polarizer is shown by forming an alignment film on a substrate and applying a liquid crystal polarizing composition onto the substrate on which the alignment film is formed.
The thickness of the liquid crystal-coated optical polarizer manufactured by this method can be made thinner than that of the film-type polarizer. The thickness of the liquid crystal-coated optical polarizer is 0.5 to 10 μm, preferably 1 to 5 μm.

The alignment film is formed by, for example, applying an alignment film-forming composition on a substrate to impart orientation to a coating film formed by rubbing, polarized light irradiation, or the like, thereby forming an alignment film on the substrate. be able to. The alignment film-forming composition contains an alignment agent, and may contain a solvent, a cross-linking agent, an initiator, a dispersant, a leveling agent, a silane coupling agent, and the like, in addition to the alignment agent. Examples of the alignment agent include polyvinyl alcohols, polyacrylates, polyamic acids, and polyimides. When photo-alignment is applied as a method of imparting the orientation, an alignment agent containing a cinnamate group is preferable.

The alignment agent may be a polymer. The polymer alignment agent has a weight average molecular weight of about 10,000 to 1,000,000. The thickness of the alignment film formed on the substrate is preferably 5 nm to 10,000 nm, and particularly preferably 10 to 500 nm, because a sufficient alignment regulating force is exhibited.

A liquid crystal polarizing composition is applied onto the base material on which the alignment film is formed, and dried if necessary to form a coating film of the liquid crystal polarizing composition. Manufacture polarizers.
The liquid crystal polarizer thus produced may be peeled from the substrate. As a method for peeling the liquid crystal coated polarizer from the base material, for example, the second base material is attached to the surface of the liquid crystal coated polarizer on which the base material is not laminated, and then the base material is peeled off. , the liquid crystal-coated polarizer-second base material, the liquid crystal-coated polarizer can be transferred to the second base material, or the second base material can be transferred to the second base material. It can also be left laminated to the substrate without being coated. It is also preferable that the base material or the second base material plays a role as a protective film, a retardation plate, or a transparent base material for a window film.

(Protective film)
The protective film is a transparent film that prevents other optical films such as polarizers and/or damage such as damage to optical devices (such as liquid crystal cells) to which the laminate 100 is attached later. The protective film can be various transparent resin films.

Here, the protective film that protects the polarizer is described. Examples of resins that form this protective film include:
Cellulose-based resin, typified by triacetyl cellulose;
Polyolefin-based resin, typified by polypropylene-based resin;
Cyclic olefin-based resins, typically norbornene-based resins;
acrylic resins, typically polymethyl methacrylate resins; and polyester resins, typically polyethylene terephthalate resins. Among these, cellulose-based resins are representative.
The thickness of the protective film can be, for example, 5-90 μm.

If necessary, the protective film contains a plasticizer, an ultraviolet absorber, an infrared absorber, a colorant such as a pigment or dye, a fluorescent brightener, a dispersant, a heat stabilizer, a light stabilizer, an antistatic agent, and an antioxidant. , a lubricant, a solvent, and the like.

A hard coat layer may be provided on at least one surface of the protective film in order to increase the scratch resistance of the surface of the protective film. The thickness of the hard coat layer is usually within the range of 2-100 μm. When the thickness of the hard coat layer is less than 2 μm, it is difficult to ensure sufficient scratch resistance. Shrinkage curling problems may occur.

The hard coat layer can be formed from a hard coat composition containing a reactive material that forms a crosslinked structure upon exposure to active energy rays or thermal energy rays. Among these, a hard coat layer obtained by irradiation with active energy rays is preferable. An active energy ray is defined as an energy ray capable of decomposing a compound that generates active species to generate active species. Visible light, ultraviolet rays, infrared rays, X-rays, α-rays, β-rays, γ-rays, electron beams, and the like can be used as active energy rays. Among these, ultraviolet rays are particularly preferred. The hard coat composition preferably contains at least one of a radical polymerizable compound and a cationically polymerizable compound. Oligomers obtained by partially polymerizing these radically polymerizable compounds and cationically polymerizable compounds may be contained in the hard coat composition.

First, the radically polymerizable compound will be described.
The radically polymerizable compound is a compound having a radically polymerizable group. The radically polymerizable group may be a functional group capable of causing a radical polymerization reaction, and examples thereof include groups containing a carbon-carbon unsaturated double bond, such as a vinyl group and a (meth)acryloyl group. . When the radically polymerizable compound has two or more radically polymerizable groups in one molecule, these radically polymerizable groups may be the same or different. When the radically polymerizable compound has two or more radically polymerizable groups in one molecule, the resulting hard coat layer tends to have improved hardness. The radically polymerizable compound is preferably a compound having a (meth)acryloyl group among them from the viewpoint of high reactivity, for example, a polyfunctional acrylate having 2 to 6 (meth)acryloyl groups in one molecule. Compounds called monomers, epoxy (meth)acrylates, urethane (meth)acrylates, polyester (meth)acrylates, which have several (meth)acryloyl groups in the molecule and have a molecular weight of several hundred to several Thousands of oligomers are mentioned. Among compounds having a (meth)acryloyl group, one or more selected from epoxy (meth)acrylates, urethane (meth)acrylates and polyester (meth)acrylates are preferred.

Next, the cationic polymerizable compound will be explained.
The cationically polymerizable compound is a compound having a cationically polymerizable group such as an epoxy group, an oxetanyl group, or a vinyl ether group. The number of cationically polymerizable groups in one molecule of the cationically polymerizable compound is preferably 2 or more, more preferably 3 or more, from the viewpoint of improving the hardness of the resulting hard coat layer. . As the cationically polymerizable compound, a compound having at least one cationically polymerizable group selected from an epoxy group and an oxetanyl group is preferable. A cyclic ether group such as an epoxy group or an oxetanyl group is advantageous in that the shrinkage associated with the polymerization reaction is small. Among the cyclic ether groups, compounds having epoxy groups are readily available in various structures from the market, and are less likely to adversely affect the durability of the resulting hard coat layer. When the hard coat composition is a mixture of a radically polymerizable compound and a cationic polymerizable compound, the compound having an epoxy group has the advantage of being easy to control compatibility with the radically polymerizable compound. In addition, among the cyclic ether groups, the oxetanyl group tends to have a higher degree of polymerization than the epoxy group, is low in toxicity, accelerates the network formation rate obtained from the cationically polymerizable compound in the resulting hard coat layer, and radically polymerizes. It has the advantage of forming an independent network without leaving unreacted monomers in the film even in a region mixed with a chemical compound.

Examples of compounds having an epoxy group include
Polyglycidyl ethers of polyhydric alcohols having alicyclic rings;
An alicyclic epoxy resin obtained by epoxidizing a cyclohexene ring- or cyclopentene ring-containing compound with a suitable oxidizing agent such as hydrogen peroxide or peracid;
Polyglycidyl ethers of aliphatic polyhydric alcohols or alkylene oxide adducts thereof;
polyglycidyl esters of aliphatic long-chain polybasic acids;
Aliphatic epoxy resins such as homopolymers and copolymers of glycidyl (meth)acrylate;
Bisphenols such as bisphenol A, bisphenol F and hydrogenated bisphenol A, or derivatives thereof such as alkylene oxide adducts and caprolactone adducts, and glycidyl ethers produced by reaction with epichlorohydrin;
and glycidyl ether type epoxy resins derived from bisphenols such as novolac epoxy resins.

The hard coat composition may further include a polymerization initiator. As the polymerization initiator, an appropriate one (radical polymerization initiator, cationic polymerization initiator, etc.) can be selected and used according to the type of polymerizable compound contained in the hard coat composition. These polymerization initiators are decomposed by at least one of active energy ray irradiation and heating to generate radicals or cations to promote radical polymerization or cationic polymerization.

Any radical polymerization initiator may be used as long as it can release a substance that initiates radical polymerization by at least one of active energy ray irradiation and heating. Examples of thermal radical polymerization initiators include organic peroxides such as hydrogen peroxide and perbenzoic acid, and azo compounds such as azobisbutyronitrile.
As active energy ray radical polymerization initiators, Type 1 type radical polymerization initiators that generate radicals by decomposition of molecules and Type 2 type radical polymerization initiators that generate radicals by hydrogen abstraction reaction in coexistence with tertiary amines are used. Yes, they can be used alone or in combination.
The cationic polymerization initiator should be capable of releasing a substance that initiates cationic polymerization by at least one of active energy ray irradiation and heating. As cationic polymerization initiators, aromatic iodonium salts, aromatic sulfonium salts, cyclopentadienyl iron (II) complexes and the like can be used. These can initiate cationic polymerization by either or both of active energy ray irradiation and heating depending on the difference in structure.

The polymerization initiator may be included in an amount of 0.1-10% by weight based on the total weight of the hard coat composition. If the content of the polymerization initiator is less than 0.1% by weight, the curing may not proceed sufficiently, and the mechanical properties of the finally obtained hard coat layer may be deteriorated. It becomes difficult or easy to realize the adhesion of the film. If the amount exceeds 10% by weight, adhesion failure, cracking, and curling may occur due to curing shrinkage during formation of the hard coat layer.

The hard coat composition may further contain one or more selected from the group consisting of solvents and additives.
The solvent is capable of dissolving or dispersing the polymerizable compound and the polymerization initiator, and any solvent known as a solvent for hard coat compositions in this technical field can be used without limitation.
The additives include inorganic particles, leveling agents, stabilizers, surfactants, antistatic agents, lubricants, antifouling agents, and the like.

Next, a method for bonding the protective film to the polarizer will be described.
The protective film for the polarizer is preferably attached to the polarizer with an adhesive. As this adhesive,
Water-based adhesives using polyvinyl alcohol-based resin aqueous solutions, water-based two-liquid urethane emulsion adhesives, or the like;
Active energy ray curable adhesion using a curable composition containing a polymerizable compound and a photoinitiator, a curable composition containing a photoreactive resin, a curable composition containing a binder resin and a photoreactive cross-linking agent, etc. agents and the like.

The polyvinyl alcohol resin contained in the polyvinyl alcohol resin aqueous solution used as an adhesive includes vinyl alcohol homopolymer obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, vinyl acetate and There are vinyl alcohol copolymers obtained by saponifying copolymers with other copolymerizable monomers, modified polyvinyl alcohol polymers obtained by partially modifying their hydroxyl groups, and the like. Polyhydric aldehydes, water-soluble epoxy compounds, melamine compounds, zirconia compounds, zinc compounds and the like may be added as additives to such water-based adhesives.

In addition, the active energy ray-curable adhesive used as the adhesive is the same as one containing a reactive material that forms a crosslinked structure upon irradiation with an active energy ray, which is exemplified as one of the hard coat compositions described above. can be mentioned.

A method of using a resin film as a protective film (or a protective film having a hard coat layer) and laminating it to a polarizer has been described above. Instead of the resin film, a thinner protective layer is directly laminated to the polarizer. It can also be used as a protective film.
As a method of directly laminating a thinner protective layer on a polarizer, for example, a coating film containing an active energy ray-curable resin is formed on the surface of the polarizer, and the coating film is cured by irradiation with an active energy ray (such as UV). Then, a protective film thinner than a conventional protective film can be directly formed on the surface of the polarizer. Examples of the active energy ray-curable resin include those containing a reactive material that forms a crosslinked structure upon irradiation with an active energy ray, which is exemplified as one of the hard coat compositions described above.

(window film)
On the other hand, a transparent protective film that prevents damage such as scratching of an optical device (liquid crystal cell, etc.) to which the laminate 100 is subsequently attached is also called a window film. For example, when the optical film 50 has a laminated structure having a plurality of films, the window film is arranged on the outermost surface of the plurality of films opposite to the surface on which the pressure-sensitive adhesive layer 80 is provided.

The window film is arranged on the viewing side of the flexible image display device, and plays a role of protecting other components from external shocks or environmental changes such as temperature and humidity. Conventionally, glass has been used as such a protective layer, but the window film in a flexible image display device is not rigid and hard like glass, but has flexible characteristics. The window film is made of a flexible transparent substrate, and may include a hard coat layer on at least one surface.

(Transparent substrate)
A transparent substrate that can be used as a window film will be described.
The transparent substrate has a visible light transmittance of 70% or more, preferably 80% or more. Any transparent polymer film can be used as the transparent substrate. In particular,
Polyolefins such as polyethylene, polypropylene, polymethylpentene, norbornene or cycloolefin derivatives having monomeric units containing cycloolefin;
(Modified) celluloses such as diacetyl cellulose, triacetyl cellulose, propionyl cellulose;
Acrylics such as methyl methacrylate (co)polymer;
Polystyrenes such as styrene (co)polymers;
acrylonitrile-butadiene-styrene copolymers, acrylonitrile-styrene copolymers;
ethylene-vinyl acetate copolymers;
Polyvinyl chlorides, polyvinylidene chlorides;
Polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate and polyarylate;
polyamides such as nylon;
polyimides, polyamideimides, polyetherimides;
polyethersulfones, polysulfones;
Polyvinyl alcohols, polyvinyl acetals;
Polyurethanes;
A film formed of polymers such as epoxy resins may be used, and a film formed of these polymers alone or in combination of two or more thereof may be used. The film can also be unstretched, monoaxially or biaxially stretched. Among the exemplified polymeric transparent substrates, preferred are polyamide films, polyamideimide films, polyimide films, polyester films, olefin films, acrylic films, and cellulose films, which are excellent in transparency and heat resistance. It is also preferable to disperse inorganic particles such as silica, organic fine particles, rubber particles, etc. in the transparent base material. In addition, colorants such as pigments and dyes, optical brighteners, dispersants, plasticizers, heat stabilizers, light stabilizers, infrared absorbers, ultraviolet absorbers, antistatic agents, antioxidants, lubricants, solvents, etc. may contain a compounding agent. The thickness of the transparent substrate is 5-200 μm, preferably 20-100 μm.

(hard coat)
A window film can also be obtained by providing a hard coat layer on at least one surface of the transparent substrate. As the hard coat layer, the same hard coat layer as the hard coat layer of the above protective film can be used.

(retardation film)
A retardation film is a transparent film having different refractive indices in two orthogonal directions within the plane, and gives a phase difference to transmitted light.
Examples of the material of the retardation film are a polycarbonate-based resin film, a polysulfone-based resin film, a polyethersulfone-based resin film, a polyarylate-based resin film, and a norbornene-based resin film.
These resin films can be given a desired retardation by stretching.
A retardation film that is readily available on the market can also be used.

The thickness of the retardation film can be, for example, 0.5-80 μm.

(brightness enhancement film)
The brightness enhancement film is a film that transmits polarized light parallel to a first in-plane direction and reflects polarized light parallel to a second direction orthogonal to the first in-plane direction. When the optical film used in the present invention has a polarizer, it is preferable to match the first direction with the transmission axis of the polarizer.

The brightness enhancement film can be a multi-layer laminate in which layers having birefringence and layers having substantially no birefringence are alternately laminated. Examples of materials for layers having birefringence are naphthalene dicarboxylic acid polyesters (e.g. polyethylene naphthalate), polycarbonates and acrylic resins (e.g. polymethyl methacrylate), examples of layers having substantially no birefringence. is a copolyester of naphthalene dicarboxylic acid and terephthalic acid.

The thickness of the brightness enhancement film can be, for example, 10-50 μm.

Each film constituting the optical film exemplified above may have a plurality of functions. For example, the protective film may be a film having an optical function such as a retardation film or a brightness enhancement film.

(Adhesion within the optical film)
When the optical film 50 has a laminated structure including a plurality of films, these films may be adhered via an adhesive. The adhesive is not particularly limited, and may be either the water-based adhesive or the active energy ray-curable adhesive described above.
A pressure-sensitive adhesive can also be used as the adhesive. This adhesive will be described later.
The thickness of the adhesive can be 1-200 μm.

(Thickness of optical film in case of laminate)
When the optical film 50 has a laminated structure including a plurality of films, the total thickness of the optical film 50 can be 10-1200 μm.

(Adhesive layer)
As described above, the laminate used in the present invention has an optical film and an adhesive layer provided on one surface thereof. This pressure-sensitive adhesive layer is formed by a pressure-sensitive adhesive. Here, the adhesive will be explained.
A pressure-sensitive adhesive is a pressure-sensitive adhesive that exhibits a soft solid (viscoelastic) state in a temperature range around room temperature (for example, 25° C.), and is a material that easily adheres to an adherend under pressure. To tell. The adhesive as used herein is described in "CA Dahlquist, Adhesion: Fundamental and Practice", McLaren & Sons, (1966), P.S. 143”, generally having properties satisfying complex tensile modulus E ^* (1 Hz) < ¹⁰⁷ dyne/ ^cm2 (typically materials having the above properties at 25°C) can be The adhesive in the technology disclosed herein can also be grasped as a solid content (non-volatile content) of the adhesive composition or a constituent component of the adhesive layer.

Examples of adhesives are compositions in which acrylic resins, styrene resins, silicone resins, etc. are used as base polymers, and cross-linking agents such as isocyanate compounds, epoxy compounds, aziridine compounds, etc. are added thereto. In this specification, the "base polymer" of the pressure-sensitive adhesive refers to the main component of the rubber-like polymer contained in the pressure-sensitive adhesive. The term "rubber-like polymer" refers to a polymer that exhibits rubber elasticity in a temperature range around room temperature. In this specification, the term "main component" refers to a component contained in an amount exceeding 50% by weight unless otherwise specified.

The thickness of the adhesive can be 1-40 μm.

(Thickness of optical film in case of laminate)
When the optical film 50 has a laminated structure including a plurality of films, the total thickness of the optical film 50 can be 10-1200 μm.

The adhesive layer 80 is provided on at least one surface of the optical film (single layer structure or laminated structure) 50 .
As the adhesive, those described above can be used.

(separator film)
The laminate 100 can have a separator film 90 on the surface of the adhesive layer 80 opposite to the surface in contact with the optical film 50 .

The separator film 90 is a film having weaker adhesion to the adhesive layer 80 than the optical film 50 . During transportation or storage of the laminate 100 before the optical film 50 is attached to another member such as an optical device (liquid crystal cell) via the adhesive layer 80, the separator film 90 covers the surface of the adhesive layer 80. Protect. The separator film 90 is easily peeled off from the adhesive layer 80 when the adhesive layer 80 is attached to another member.

The separator film need not be transparent, but is preferably transparent. An example of a separator film material is polyethylene terephthalate. The thickness of the separator film can be 1-40 μm.

(protection film)
Moreover, the laminate 100 can have a protective film 70 disposed on the outer surface of the optical film 50 opposite to the surface on which the adhesive layer 80 is provided.
The protective film 70 is used during processing of the laminate 100, when attaching the laminate 100 to an optical device (such as a liquid crystal cell), or during transportation of an optical device to which the laminate 100 is attached. and/or has a function of suppressing scratches on the optical film 50 .

Examples of materials for such protective films are polyethylene terephthalate, polyethylene, polypropylene and the like. The protective film 70 does not have to be transparent, but is preferably transparent. The thickness of the protective film can be 1-40 μm.

The protective film 70 can also be a film that protects the optical film 50 until the product using the optical film 50 is used. In this case, the protective film 70 is not peeled off from the optical film 50 even after the optical film 50 is attached to the optical device (liquid crystal cell, etc.) via the adhesive layer 80 .

The protective film 70 can be attached to the optical film 50 via an adhesive layer or by self-adhesion through electrostatic adsorption.

A specific example of the laminate structure of the laminate 100 is shown in FIGS. 2(a) and 2(b).
In the laminate 100 of FIG. 2(a), the protective film 70, the protective film 2, the polarizer 3, the protective film 2, the adhesive layer 80, and the separator film 90 are laminated in this order. The protective film 2 , the polarizer 3 and the protective film 2 constitute an optical film 50 .

In the laminated body 100 of FIG. 2(b), the protective film 70, the protective film 2, the polarizer 3, the adhesive layer 80, and the separator film 90 are laminated in this order. The protective film 2 and the polarizer 3 constitute an optical film 50 . Although not shown, in any example, the films in each optical film 50 can be adhered with an adhesive or a pressure-sensitive adhesive.

(Laminate for flexible image display device)
The optical film 50 used in the present invention may be a laminate for a flexible image display device that is used for a flexible image display device that can be folded or the like.
A typical example of this flexible image display device is an image display device having a laminate for a flexible image display device and an organic EL display panel. In this typical example, the laminate for a flexible image display device is usually arranged on the viewing side with respect to the organic EL display panel, and the flexible image display device is configured to be foldable. The laminate for a flexible image display device may contain a window film, a circularly polarizing plate, and a touch sensor, and their lamination order is arbitrary. It is preferably configured in the order of lamination or the order of lamination of the window film, the touch sensor and the circularly polarizing plate. When the circularly polarizing plate is present on the viewing side of the touch sensor, the pattern of the touch sensor becomes less visible and the visibility of the displayed image is improved, which is preferable. Each member can be laminated using an adhesive, a pressure-sensitive adhesive, or the like. Also, a light shielding pattern may be formed on at least one surface of any one of the window film, the circularly polarizing plate, and the touch sensor.

(Circularly polarizing plate)
A circularly polarizing plate is a functional film having a function of transmitting only a right-handed or left-handed circularly polarized component by laminating a λ/4 retardation film, which is a retardation film, on a linear polarizer. When the external light entering the display device passes through the circularly polarizing plate arranged on the viewing side, it is converted into right-handed circularly polarized light and emitted to the organic EL panel side. When this right-handed circularly polarized light is reflected (reflected light) by the metal electrode of the organic EL panel, this reflected light becomes left-handed circularly polarized light. Since this left-handed circularly polarized light cannot pass through the circularly polarizing plate, as a result, this reflected light is not emitted outside the display device. Due to such a function, only the light emitting component of the organic EL is visible on the display panel of the display device, and by transmitting only the light emitting component, the influence of the reflected light can be prevented to make the image easier to see. can.

In order to achieve the circular polarization function, the absorption axis of the linear polarizer and the slow axis of the λ/4 retardation plate should theoretically be 45°, but practically 45±10°. The linear polarizing plate and the λ/4 retardation plate do not necessarily have to be laminated adjacent to each other as long as the relationship between the absorption axis and the slow axis satisfies the above range. Although it is preferable to achieve perfect circular polarization at all wavelengths, it is not always necessary in practice, so the circularly polarizing plate in the present invention also includes an elliptically polarizing plate. It is also preferable to further laminate a λ/4 retardation plate on the viewing side of the linear polarizing plate to circularly polarize the emitted light, thereby improving the visibility when wearing polarized sunglasses.

A linear polarizing plate is a functional layer having a function of transmitting light oscillating in the direction of the transmission axis, but blocking the polarization of the oscillating component perpendicular thereto. The linear polarizing plate usually has a structure including a polarizer and a protective film attached to at least one surface of the polarizer. This polarizer may be either the film-type polarizer or the liquid crystal-coated polarizer described above. The already explained protective film can also be used. The thickness of the linearly polarizing plate constituting the circularly polarizing plate is preferably 200 μm or less, more preferably 0.5 μm to 100 μm. If the thickness exceeds 200 μm, the flexibility (flexibility) that can be applied to the flexible image display device laminate may decrease. Suitable thickness of the linear polarizing plate can be adjusted by appropriately adjusting the thicknesses of the polarizer and protective film described above.

The λ/4 retardation plate, which is a retardation film, is also called a quarter-wave plate, and gives a phase difference of π/2 (=λ/4) to the plane of polarization of incident light. be. A retardation film having such performance can be selected from the retardation films described above to prepare a λ/4 retardation plate, but as another example, a liquid crystal formed by applying a liquid crystal composition The coating type retardation plate can also be a λ/4 retardation plate. A liquid crystal-coated retardation plate formed by applying this liquid crystal composition can obtain a λ/4 retardation plate having an extremely thin thickness, as described later. Therefore, this liquid crystal-coated retardation plate is particularly preferable as a λ/4 retardation plate constituting a circularly polarizing plate of a laminate for a flexible image display device.

Here, the liquid crystal composition forming the λ/4 retardation plate will be described.
The liquid crystal composition includes a liquid crystalline compound exhibiting a nematic, cholesteric, smectic, or other liquid crystal state. The liquid crystalline compound has a polymerizable functional group. The liquid crystal composition may contain a plurality of types of liquid crystal compounds, and when it contains a plurality of types of liquid crystal compounds, at least one of the liquid crystal compounds has a polymerizable functional group. The liquid crystal composition may further contain initiators, solvents, dispersants, leveling agents, stabilizers, surfactants, cross-linking agents, silane coupling agents, and the like. The liquid crystal-coated retardation plate is obtained by coating and curing a liquid crystal composition on an alignment film of a substrate on which an alignment film is formed in advance, in the same manner as described in the manufacturing method of the liquid crystal polarizer. It can be manufactured by forming a liquid crystal retardation layer thereon. The liquid crystal coating type retardation plate can be formed to be thinner than the stretching type retardation plate. The thickness of the liquid crystal polarizing layer is 0.5-10 μm, preferably 1-5 μm. The liquid crystal-coated retardation plate can be laminated by peeling from the base material and transferred, or the base material can be laminated as it is. It is also preferable that the base material plays a role as a protective film or a transparent base material for a retardation plate.

Many of the general materials constituting the retardation film exhibit larger birefringence at shorter wavelengths and smaller birefringence at longer wavelengths. In this case, since it is not possible to achieve a retardation of λ / 4 in the entire visible light region, an in-plane retardation of 100 to 180 nm, preferably 130 It is often designed to be ~150 nm. It is preferable to use a reverse-dispersion λ/4 retardation plate using a material having a birefringence wavelength dispersion characteristic opposite to that of a normal one, because it can improve visibility. As such materials, it is also preferable to use those described in JP-A-2007-232873 and the like in the case of a stretched retardation plate, and those described in JP-A-2010-30979 in the case of a liquid crystal-coated retardation plate. .

In addition, as another method for forming a preferable retardation film that constitutes a circularly polarizing plate, a technique for obtaining a broadband λ/4 retardation plate by combining with a λ/2 retardation plate is also known (Japanese Patent Application Laid-Open No. 10-90521). The λ/2 retardation plate is also manufactured by a material method similar to that of the λ/4 retardation plate. The combination of the stretched retardation plate and the liquid crystal-coated retardation plate is arbitrary, but it is preferable to use the liquid crystal-coated retardation plate for both because the thickness of the film can be reduced.

A method of laminating a positive C plate on the circularly polarizing plate in order to improve visibility in oblique directions is also known (Japanese Patent Application Laid-Open No. 2014-224837). This positive C plate may also be a liquid crystal-coated retardation plate or a stretched retardation plate. The retardation in the thickness direction of this positive C plate is -200 to -20 nm, preferably -140 to -40 nm.

(touch sensor)
A touch sensor is used as an input means. Various types of touch sensors have been proposed, such as a resistive film type, a surface acoustic wave type, an infrared type, an electromagnetic induction type, and an electrostatic capacity type, and any type may be used. Among these, the capacitance method is preferable.

A capacitive touch sensor is divided into an active area and a non-active area located outside the active area when viewed from a display panel surface. The active area is an area corresponding to the area (display part) where the screen is displayed on the display panel, and is an area where a user's touch is sensed. display area).
The touch sensor includes a flexible substrate; sensing patterns formed in an active region of the substrate; and formed in a non-active region of the substrate and connected to an external driving circuit through the sensing patterns and pads. Each sensing line can be included for As the flexible substrate, a substrate made of the same material as the transparent substrate of the window film can be used. The substrate of the touch sensor preferably has a toughness of 2,000 MPa % or more from the viewpoint of suppressing cracks in the touch sensor. More preferably, the toughness may be 2,000 MPa% to 30,000 MPa%.

The sensing patterns may include first patterns formed in a first direction and second patterns formed in a second direction. The first pattern and the second pattern are arranged in different directions. The first pattern and the second pattern are formed in the same layer, and each pattern should be electrically connected to sense a touched point. The first pattern has a form in which each unit pattern is connected to each other through joints, but the second pattern has a structure in which each unit pattern is separated from each other in an island form. A separate bridge electrode is required for direct connection. The sensing pattern is formed from a known transparent electrode material. Examples of transparent electrode materials include indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium zinc tin oxide (IZTO), cadmium tin oxide (CTO), and PEDOT. (poly(3,4-ethylenedioxythiophene)), carbon nanotube (CNT), graphene, metal wire (the metal used for the metal wire is not particularly limited, for example, silver, gold, aluminum, copper, iron, nickel, titanium , terenium, chromium, etc. These can be used alone or in admixture of two or more.), etc., and these can be used alone or in admixture of two or more. . ITO is preferred. A bridge electrode may be formed on the insulating layer above the sensing pattern via an insulating layer, and the bridge electrode may be formed on the substrate, and the insulating layer and the sensing pattern may be formed thereon. The bridge electrodes may be made of the same material as the sensing pattern, such as metals such as molybdenum, silver, aluminum, copper, palladium, gold, platinum, zinc, tin, titanium, or alloys of two or more thereof. You can also Since the first pattern and the second pattern should be electrically insulated, an insulating layer is formed between the sensing pattern and the bridge electrode. The insulating layer may be formed only between the joints and the bridge electrodes of the first pattern, or it may be formed in a structure of layers covering the sensing pattern. In the latter case, the bridge electrode can connect the second pattern through a contact hole formed in the insulating layer. The touch sensor is characterized by the difference in transmittance between patterned areas and non-patterned areas, specifically the difference in optical transmission induced by the difference in refractive index in these areas. An optical adjustment layer may further be included between the substrate and the electrode as a means to properly compensate for the difference. The optical adjustment layer may include an inorganic insulating material or an organic insulating material. The optical adjustment layer may be formed by coating a photocurable composition containing a photocurable organic binder and a solvent on a substrate. The photocurable composition may further include inorganic particles. The inorganic particles may increase the refractive index of the optical adjustment layer.
The photocurable organic binder may include, for example, copolymers of monomers such as acrylate-based monomers, styrene-based monomers, and carboxylic acid-based monomers. The photocurable organic binder may be, for example, a copolymer containing different repeating units such as epoxy group-containing repeating units, acrylate repeating units, and carboxylic acid repeating units.
The inorganic particles can include, for example, zirconia particles, titania particles, alumina particles, and the like.
The photocurable composition may further include additives such as a photopolymerization initiator, a polymerizable monomer, and a curing aid.

Each layer (window film, circularly polarizing plate, touch sensor) forming the laminate for a flexible image display device can be formed with an adhesive. As the adhesive, water-based adhesives, active energy ray-curable adhesives, and pressure-sensitive adhesives, which have already been described, are often used.

(Shading pattern)
The light shielding pattern can be applied as at least part of a bezel or housing of the flexible image display device. The visibility of the image is improved by hiding the wiring arranged at the peripheral portion of the flexible image display device by the light shielding pattern and making it difficult to see. The light shielding pattern may be in the form of a single layer or multiple layers. The color of the light-shielding pattern is not particularly limited, and various colors such as black, white, and metallic color may be used. The light-shielding pattern may be formed of a pigment for realizing color and a polymer such as acrylic resin, ester resin, epoxy resin, polyurethane, silicone resin, or the like. These may be used singly or as a mixture of two or more. The light-shielding pattern can be formed by various methods such as printing, lithography, and inkjet. The thickness of the light shielding pattern may be 1 μm to 100 μm, preferably 2 μm to 50 μm. Moreover, a shape such as an inclination may be given to the thickness direction of the light shielding pattern.

The optical film and adhesive contained in the laminate used in the manufacturing method of the present invention have been described above. Next, the manufacturing method of the present invention will be described.

(powder)
Again, referring to (a) and (b) of FIG. 1, the manufacturing method of the present invention will be described.
The powder f adhering to the end face E of the optical film 50 adheres to the end face by processing the end face of the laminate 100 . Generally, the end face of the laminate 100 is processed to obtain the laminate 100 of a desired size from the original roll of the laminate 100 . Examples of processing are cutting, milling and grinding. Here, cutting is a concept including drilling. Therefore, as described above, the end face of the laminate 100 includes not only the outer end face E of the laminate 100 as shown in FIG. It also includes the forming inner end face E.

Cutting is the process of making a cut from the front surface to the back surface of the laminate by inserting a blade, removing with a laser, or the like, thereby defining the general shape of the laminate.

Cutting is a process of forming a new end face by scraping off a part of the end by bringing a relatively moving bit (blade) into contact with the end of the laminate. Moreover, as described above, this cutting includes drilling. For example, as shown in FIG. 1B, the drilling process is a process of forming a hole H at a desired position in the laminate 100 using a drill or the like. In such a drilling process, powder f (drilling dust) may adhere to the inner end face E forming the inner wall of the hole H. As shown in FIG.

Polishing is a process of bringing relatively moving abrasive grains (either fixed abrasive grains or free abrasive grains) into contact with the end face of the laminate to grind a part of the end face. Polishing also includes a process called grinding.

For example, after cutting the original fabric of the laminate 100 into a planar shape slightly larger than the desired size with a blade or laser, the planar shape of the laminate is predetermined by grinding and / or polishing the end face of the cut laminate. It can be dimensioned, and the squareness and flatness of the end faces can be enhanced.

There is no particular limitation on the planar shape of the laminate (shape viewed from the thickness direction). For example, it can be square, rectangular, circular, and the like.

Due to these processes on the end face of the laminate, powder of the material forming the laminate 100 is generated, and a portion of the powder adheres to the end face E of the laminate 100 . Therefore, performing these processes on the laminate is one embodiment of the preparatory step in the manufacturing method of the present invention. The end surface E can be a surface that connects the two main surfaces of the laminate 100 .

The average particle size of the powder can be, for example, 10-3000 μm. This particle size is the D50 of the weight-based particle size distribution according to the laser diffraction method.

(Collision process (powder removal process by collision of dry ice particles))
Subsequently, dry ice particles are caused to collide with the end face E of the laminate 100 to remove the powder f on the end face.

Specifically, it is preferable to convey dry ice particles by gas and cause them to collide with the end surface E of the laminate 100 .

Although the average particle diameter of the dry ice particles to be collided is not particularly limited, it is preferably 100 μm or more from the viewpoint of efficiently removing the powder. Moreover, from the viewpoint of suppressing chipping of the pressure-sensitive adhesive layer due to collision with dry ice, the thickness is preferably 1000 μm or less.

The average particle size of dry ice particles can be measured with a laser Doppler anemometer.

The speed of the impinging dry ice particles can be from 5 m/sec to 100 m/sec.

The carrier gas for dry ice is not particularly limited, and can be, for example, nitrogen, air, or carbon dioxide gas.

Specifically, a dry ice particle supply unit (apparatus) 300 as shown in FIG. 3 can be used.

The apparatus comprises a liquid carbon dioxide source 310, a nozzle 320, a carrier gas source 330, a line L1 connecting the liquid carbon dioxide source 310 and the nozzle 320, and a line L2 connecting the carrier gas source 330 and the nozzle 320.

A valve 340 and an orifice 350 are provided on the line L1, and a valve 360 is provided on the line L2.

Valve 340 is opened to adiabatically expand the liquid of liquid carbon dioxide source 310 through orifice 350 to produce dry ice particles (dry ice snow) that are delivered to nozzle 320 . The valve 360 is opened to supply the gas from the carrier gas source 330 to the nozzle 320 to blow out the dry ice particles d from the nozzle 320 and supply them to the end face E of the laminate 100 .

The particle size of the dry ice particles d can be adjusted by adjusting the distance (adiabatic expansion distance) from the adiabatic expansion at the orifice 350 to the blowout from the nozzle 320 and the distance (injection distance) between the nozzle 320 and the supply target of the dry ice particles. . It is also possible to conduct an appropriate preliminary experiment using a dry ice particle supply unit (apparatus), confirm the degree of removal of the powder f, and adjust the adiabatic expansion distance and the injection distance.

The distance (jetting distance) between the nozzle 320 and the end surface E of the laminate 100 is preferably less than 20 mm. Also, the adiabatic expansion distance can be, for example, 10 to 500 mm.

It is preferable to relatively move the positions of the laminate 100 and the nozzle 320 by the conveying unit 400 and scan the end face E with the portion with which the dry ice particles d collide. For example, in FIG. 3, the layered product 100 is moved by using the conveying unit 400 so that the collision portion of the dry ice particles d at the end face E moves in a plane orthogonal to the blowing direction (horizontal direction) of the dry ice particles d. can be scanned.
The scanning speed of the collision portion of the dry ice particles d on the end face E can be 1 to 100 m/sec.

(action)
According to the present embodiment, since the dry ice particles d are blown onto the end surface E of the laminate 100, powder such as cutting dust, cutting dust, drilling dust, and polishing dust is preferably removed from the end surface. . This is preferable because contamination by powder in the post-process is reduced. In addition, it takes less time to remove the powder compared to the method of sticking and peeling off the tape.
Further, when the particle size of the dry ice particles to be collided is 100 to 1000 μm, chipping of the adhesive layer on the end face can be suppressed while increasing the removal rate of powder, and it is more preferable to be 200 to 700 μm.

(Removal of powder from laminated structure obtained by laminating a plurality of laminated bodies)
In the above description, dry ice particles collide with one laminate 100, but as shown in FIG. Impingement is also preferred. According to this, mass processing of the laminated body 100 is attained.

(Order of end face processing and powder removal)
After the processing (cutting, cutting, and polishing) of a part of the end surface of the laminate 100 is completed, while the other portion of the end surface of the laminate 100 is being processed, the processing of the end surface is completed simultaneously. Powder may be removed by blowing dry ice particles to the exposed portion. This makes it possible to shorten the process time.

On the contrary, after finishing all the processing such as cutting, cutting, polishing, etc. on the end face of the laminate, the dry ice particles are caused to collide with the end face of the laminate 100 to clean the powder on the end face, and the dry ice particles are caused to collide with the end face. At that time, other portions of the end face of the laminate may not be processed. In this case, it is possible to separate the atmosphere (space) in which powder is removed by the collision of dry ice particles and the atmosphere (space) in which the end face is processed, so it is possible to prevent contamination of the end face due to powder generated by processing. becomes.

(Atmosphere during collision process (powder removal process))
The atmosphere around the laminate and the laminate structure during the step of removing the powder on the end face of the laminate and the laminate structure with dry ice particles can be an air atmosphere, but if necessary, nitrogen, carbon dioxide gas, or the like can be used. Atmosphere is fine. The temperature of the atmosphere is usually 20-30°C, preferably 20-27°C. The relative humidity of the atmosphere is usually less than 80%, preferably 30-75%, more preferably 40-70%. When the relative humidity of the atmosphere reaches 80% or more, condensation occurs due to the cooling of the laminate or laminate structure, and highly water-absorbent films (e.g., polarizers) in the laminate absorb water and swell, resulting in lamination. It may cause defects in the appearance and optical properties of the body and laminated structure.

(Optical member manufacturing equipment)
Next, with reference to FIG. 5, an optical member manufacturing apparatus 1000 suitable for carrying out the above method will be described.

This manufacturing apparatus 1000 includes an end surface processing unit 200 that processes, such as cutting, cutting, or polishing, the end surface of the laminate 100 or the laminate structure 120, and dry ice is added to the portion of the laminate 100 that has been processed by the end surface processing unit 200. A dry ice particle supply unit 300 for colliding particles and a transport unit 400 for transporting the laminate 100 are provided.

In FIG. 5 , a cutting device is drawn as the end face processing unit 200 . This cutting device comprises a horizontally extending rotary shaft 210 , a disc 220 attached to the rotary shaft, and a cutting tool 230 attached to the disc 220 . By rotating the cutting tool 230, it is possible to cut the end face of the laminate or the like.

For the dry ice particle supply unit 300, only the nozzle 320 is shown for simplicity.

The conveying unit 400 includes a pair of upper jig 420 and lower jig 422 that sandwich and support the laminate 100 or laminated structure 120 in the thickness direction, and a cylinder that presses the upper jig 420 in the thickness direction (downward). 430, a rotation mechanism 410 that is connected to the lower jig 422 and rotates the upper jig 420 and the lower jig 422 around a vertical axis (Z-axis), and a rotating mechanism 410 that rotates the upper jig 420 and the lower jig 422 in the horizontal direction (X-axis). direction).

Next, a method for manufacturing an optical member using this apparatus will be described. First, the laminate 100 or laminate structure 120 is sandwiched between the upper jig 420 and the lower jig 422 . Next, the cylinder 430 presses the upper jig 420 toward the lower jig 422 to fix the laminate 100 or the laminate structure 120 . In this embodiment, the laminate 100 or laminate structure 120 is rectangular when viewed from above and has four end faces. Therefore, the rotating mechanism 410 adjusts the rotational position of the laminate 100 or the laminate structure 120 so that the two end faces E are oriented parallel to the X-axis.

Subsequently, the end face processing section 200 is activated. Specifically, the disk 220 is rotated. Next, the moving mechanism 440 moves the laminate 100 and the laminate structure 120 in the X direction so that the end surface E and the cutting tool 230 of the end surface processing unit 200 are brought into contact with each other. Thereby, a pair of end surfaces E of the laminate 100 and the laminate structure 120 facing each other are cut by the cutting tool 230 . At this time, cutting chips adhere to the end face E.

Subsequently, the transport unit 400 moves the layered body 100 and the layered structure 120 in the −X direction, and supplies dry ice particles from the nozzle 320 of the dry ice particle supply unit 300 . As a result, the dry ice particles collide with the cut end faces E of the laminate 100 and the laminated structure 120, and the powder on the end faces E is removed.

Subsequently, the layered product 100 and the layered structure 120 are further moved in the - direction by the conveying unit 400, and the remaining two end faces are parallel to the X direction by the rotating mechanism 410. Rotate 120. After that, in the same manner as before, processing of the remaining two end faces and subsequent removal of powder by dry ice particles may be performed in order.

The end surface processing part 200 can be formed in various forms depending on the mode of processing. For example, as shown in FIG. 6, a plane-type rotary blade having a cylindrical body 240 rotating around a vertical axis and a long blade 250 provided on the outer peripheral surface of the cylindrical body 240 so as to extend in the axial direction is used for cutting. may be performed.

Further, instead of the cutting tool 230, polishing can be performed by using a polishing plate having a large number of abrasive grains provided on the surface of the disc.

It can also be used as a cutting device when cutting and polishing are not required.

Finally, an example of a method for removing the powder f (punching dust) adhering to the end face E of the hole H provided in the laminate 100 will be described with reference to FIG.

First, a plurality of laminates 100 having powder (punching dust) f adhering to the inner end faces E of the holes H are prepared by punching each laminate 100 . As shown in FIG. 1B, each laminate 100 has a hole H provided at a predetermined position by drilling. Next, the laminate structure 120 is obtained by laminating these laminates 100 such that the positions of the holes H of the laminates 100 are aligned on one axis (the axis extending in the thickness direction). As a result, the holes H of the stacked laminates 100 are connected to form a through hole H' penetrating through the laminate structure 120 in the thickness direction thereof.

Among a pair of upper jig 420 and lower jig 422 for pressing the laminated structure 120 in the thickness direction, one jig is provided with a dry ice particle supply port 420a and the other jig is provided with a dry ice particle recovery port 422b in advance. set aside. An upper jig 420 and a lower jig 422 are arranged so that the through holes H′ communicate with the dry ice particle supply port 420a and the dry ice particle recovery port 422b, and the laminated structure 120 is stretched in the thickness direction. to press. This completes the preparatory process before the dry ice collision process.

Next, dry ice particles are supplied from the nozzle 320 into the through hole H' via the dry ice particle supply port 420a (impingement step). The dry ice particles ejected from the nozzle 320 spread in the width direction as they advance, collide with the end face E of the through hole H' of the laminated structure 120, and are discharged together with the powder f from the dry ice particle recovery port 422b. By using such a device, the powder f can be efficiently removed from the laminate 100 having the powder f adhering to the end face E, which is the inner wall of the hole H, by drilling.

(Laminate raw fabric)
Protective film (made of PET (polyethylene terephthalate): 53 μm) / protective film (made of TAC (triacetylcellulose): 32 μm) / polarizer (PVA (iodine-adsorbing polyvinyl alcohol): 12 μm) / protective film (COP (cyclic olefin resin ): 23 μm)/adhesive layer (acrylic adhesive: 20 μm)/separator film (PET: 38 μm).
The protective film and the polarizer were adhered with a water-based adhesive. The thickness of the laminate was 178 μm.

(Processing of end face of laminate)
The raw fabric laminate was punched out into a rectangular shape with a size of 140×65 mm with a Thomson blade to obtain a laminate.

Next, 50 laminates were stacked to obtain a laminate structure. Each end face of the laminated structure was cut by a cutting device. After that, each end surface of the laminated structure was polished by a polishing device.

(Removal of powder on end face of laminate)
For each example and comparative example, powder was removed from the end face of the laminate under the following conditions.

(Example 1)
Dry ice particle supply device: Carbon dioxide type dry ice blast _CO2 pressure: 5 MPa ( _CO2 pressure is the supply pressure to the orifice.)
Air pressure: 0.5MPa
Distance between nozzle tip and end face: about 50 mm
Nozzle scanning speed: 50 mm/5 seconds Nozzle center position and nozzle scanning direction: The nozzle was directed to the center of the end surface of the laminated structure in the thickness direction, and the nozzle was scanned in the direction orthogonal to the thickness of the end surface of the laminated structure. .
Average particle size of dry ice particles: 1 to 100 μm
Ambient temperature: 24°C to 26°C, ambient relative humidity: 45% to 65%

(Example 2)
Dry ice particle supply device: Carbon dioxide type dry ice blast CO ₂ pressure: 7 MPa
Air pressure: 0.5MPa
Distance between nozzle tip and end face: about 50 mm
Nozzle scanning speed: 50 mm/5 seconds Nozzle center position and nozzle scanning direction: The nozzle was directed to the center of the end surface of the laminated structure in the thickness direction, and the nozzle was scanned in the direction orthogonal to the thickness of the end surface of the laminated structure. .
Average particle diameter of dry ice particles: 200 to 700 μm or less Ambient temperature: 24° C. to 26° C. Relative humidity of atmosphere: 45% to 65%

(Example 3)
Dry ice particle supply device: pellet type dry ice blast pellet diameter: φ3mm
Air pressure: 0.5MPa
Distance between nozzle tip and end face: about 50mm
Nozzle scanning speed: 50 mm/5 seconds Nozzle center position and nozzle scanning direction: The nozzle was directed to the center of the end surface of the laminated structure in the thickness direction, and the nozzle was scanned in the direction orthogonal to the thickness of the end surface of the laminated structure. .
Average particle size of dry ice particles: 1000 μm or more Ambient temperature: 24° C. to 26° C. Relative humidity of atmosphere: 45% to 65%

(Example 4)
Powder was removed from the end face of the laminate under the same conditions as in Example 2, except that the ambient temperature was 26° C. and the relative humidity of the atmosphere was 80 to 90%.
The laminate was cooled by contact with dry ice particles during removal, and dew condensation occurred in the laminate. When confirming the part where dew condensation had occurred, there was no polishing dust or chipping, but swelling had occurred at the end of the laminate.

(Comparative example 1)
A clean room wiper (manufactured by Kuraray Kuraflex Co., Ltd.) impregnated with ethanol was used to wipe the end face of the laminated structure.

(Comparative example 2)
An OLFA cutter knife was moved along the edge of the laminated structure.

(Comparative Example 3)
After sticking an adhesive tape (CELLOTAPE (registered trademark) manufactured by Nichiban Co., Ltd.) to the end face of the laminated structure, the adhesive tape was peeled off from the end face.

(Comparative Example 4)
An air flow was blown onto the end surface of the laminated structure in the same manner as in Example 1, except that liquid carbon dioxide was not supplied.

(evaluation)
The end face was observed with a microscope to examine the state of residual powder on the end face and the presence or absence of chipping of the adhesive layer on the end face.

Table 1 shows the results.

In addition, ○ of "powder residue on the end face" indicates that no powder is observed in a field of view of 30 mm in length (hereinafter simply referred to as length) in the direction perpendicular to the thickness, and △ indicates a length of 30 mm. 1 to 2 powders were observed in a narrow field of view, and × indicates that 3 or more powders were observed in a 30 mm long field of view.

In addition, ◯ in "chipping of the adhesive layer on the end surface" indicates that chipping is not observed in a field of view of 30 mm in length (hereinafter simply referred to as length) in the direction orthogonal to the thickness, and △ is 30 mm. 1 or 2 chippings were observed in the long visual field, and x indicates that 3 or more chippings were observed in the 30 mm long visual field.

50... Optical film 80... Adhesive layer 100... Laminated body 120... Laminated structure 200... End face processing unit 300... Dry ice particle supply unit 400... Conveying unit 1000... Optical member manufacturing apparatus f ... powder, E ... end face.

Claims (11)

a step of preparing a laminate having an optical film and an adhesive layer provided on one surface of the optical film and having powder adhered to an end surface thereof;
Colliding dry ice particles against the end face of the laminate to remove the powder from the end face,
The laminate has a hole penetrating in the thickness direction of the optical film and the pressure-sensitive adhesive layer,
A method for manufacturing an optical member, wherein the end face is an inner wall of the hole. The method of claim 1, wherein said dry ice particles have an average particle size of 100-1000 µm. In the preparing step, the laminate having the optical film and the adhesive layer is provided with the hole using a drill to prepare the laminate having the powder adhered to the end face. 3. A method according to claim 1 or 2. 4. The method according to any one of claims 1 to 3 , wherein in the step of colliding, the dry ice particles collide with an end face of a laminated structure in which a plurality of the laminated bodies are laminated. 3. At least one selected from the group consisting of cutting, grinding, and polishing is performed on the other portion of the end surface of the laminate at the same time that the dry ice particles collide with the portion of the end surface. 4. The method according to any one of 1 to 3 . In the preparing step, the end face is subjected to at least one selected from the group consisting of cutting, cutting, and polishing, and when the dry ice particles collide with a part of the end face, the end face is 3. The method of claim 1 or 2, wherein none selected from said group is performed. The optical film is at least one selected from the group consisting of a polarizer, a protective film, a retardation film, a brightness enhancement film, a window film, and a touch sensor. The method according to any one of claims 1 to 6 , which is a laminated film containing two or more, or a laminated film containing at least two selected from the above group. The method according to any one of claims 1 to 7 , wherein the relative humidity of the atmosphere in the step of colliding the dry ice particles with the end face is 30 to 75%. an end surface processing unit that cuts, cuts, or polishes an end surface of an optical film and a laminate having an adhesive layer provided on one surface of the optical film;
a dry ice particle supply unit that causes dry ice particles to collide with the portion of the laminate processed by the end face processing unit,
The laminate has a hole penetrating in the thickness direction of the optical film and the pressure-sensitive adhesive layer,
An apparatus for manufacturing an optical member, wherein the end surface is an inner wall of the hole. The end face processing unit has a drill,
10. The apparatus for manufacturing an optical member according to claim 9, wherein said hole is formed by said drill. 11. The apparatus for manufacturing an optical member according to claim 9 , further comprising a conveying section for moving said laminate between said end face processing section and said dry ice particle supply section.

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